diff options
| -rw-r--r-- | ChangeLog | 32 | ||||
| -rw-r--r-- | Makefile.in | 4 | ||||
| -rw-r--r-- | auth.c | 606 | ||||
| -rw-r--r-- | auth.h | 6 | ||||
| -rw-r--r-- | bufaux.c | 53 | ||||
| -rw-r--r-- | bufaux.h | 5 | ||||
| -rw-r--r-- | channels.c | 1194 | ||||
| -rw-r--r-- | channels.h | 194 | ||||
| -rw-r--r-- | cipher.c | 123 | ||||
| -rw-r--r-- | cipher.h | 22 | ||||
| -rw-r--r-- | clientloop.c | 205 | ||||
| -rw-r--r-- | compress.c | 40 | ||||
| -rw-r--r-- | dispatch.c | 78 | ||||
| -rw-r--r-- | dispatch.h | 11 | ||||
| -rw-r--r-- | log-server.c | 12 | ||||
| -rw-r--r-- | mpaux.c | 8 | ||||
| -rw-r--r-- | nchan.c | 9 | ||||
| -rw-r--r-- | nchan.h | 4 | ||||
| -rw-r--r-- | packet.c | 3 | ||||
| -rw-r--r-- | pty.h | 4 | ||||
| -rw-r--r-- | readconf.c | 3 | ||||
| -rw-r--r-- | serverloop.c | 195 | ||||
| -rw-r--r-- | session.c | 1153 | ||||
| -rw-r--r-- | session.h | 7 | ||||
| -rw-r--r-- | ssh.c | 3 | ||||
| -rw-r--r-- | ssh.h | 171 | ||||
| -rw-r--r-- | ssh2.h | 106 | ||||
| -rw-r--r-- | sshd.8 | 10 | ||||
| -rw-r--r-- | sshd.c | 1855 |
29 files changed, 3410 insertions, 2706 deletions
@@ -1,3 +1,35 @@ +20000401 + - Big OpenBSD CVS update (mainly beginnings of SSH2 infrastructure) + - [auth.c session.c sshd.c auth.h] + split sshd.c -> auth.c session.c sshd.c plus cleanup and goto-removal + - [bufaux.c bufaux.h] + support ssh2 bignums + - [channels.c channels.h clientloop.c sshd.c nchan.c nchan.h packet.c] + [readconf.c ssh.c ssh.h serverloop.c] + replace big switch() with function tables (prepare for ssh2) + - [ssh2.h] + ssh2 message type codes + - [sshd.8] + reorder Xr to avoid cutting + - [serverloop.c] + close(fdin) if fdin != fdout, shutdown otherwise, ok theo@ + - [channels.c] + missing close + allow bigger packets + - [cipher.c cipher.h] + support ssh2 ciphers + - [compress.c] + cleanup, less code + - [dispatch.c dispatch.h] + function tables for different message types + - [log-server.c] + do not log() if debuggin to stderr + rename a cpp symbol, to avoid param.h collision + - [mpaux.c] + KNF + - [nchan.c] + sync w/ channels.c + 20000326 - Better tests for OpenSSL w/ RSAref - Added replacement setenv() function from OpenBSD libc. Suggested by diff --git a/Makefile.in b/Makefile.in index 6fee608df..43870d5f9 100644 --- a/Makefile.in +++ b/Makefile.in @@ -31,11 +31,11 @@ LDFLAGS=-L. @LDFLAGS@ TARGETS=ssh sshd ssh-add ssh-keygen ssh-agent scp $(EXTRA_TARGETS) -LIBOBJS= atomicio.o authfd.o authfile.o bsd-bindresvport.o bsd-daemon.o bsd-misc.o bsd-mktemp.o bsd-rresvport.o bsd-setenv.o bsd-snprintf.o bsd-strlcat.o bsd-strlcpy.o bufaux.o buffer.o canohost.o channels.o cipher.o compat.o compress.o crc32.o deattack.o fake-getaddrinfo.o fake-getnameinfo.o fingerprint.o hostfile.o key.o log.o match.o mpaux.o nchan.o packet.o radix.o random.o readpass.o rsa.o tildexpand.o ttymodes.o uidswap.o xmalloc.o +LIBOBJS= atomicio.o authfd.o authfile.o bsd-bindresvport.o bsd-daemon.o bsd-misc.o bsd-mktemp.o bsd-rresvport.o bsd-setenv.o bsd-snprintf.o bsd-strlcat.o bsd-strlcpy.o bufaux.o buffer.o canohost.o channels.o cipher.o compat.o compress.o crc32.o deattack.o dispatch.o fake-getaddrinfo.o fake-getnameinfo.o fingerprint.o hostfile.o key.o log.o match.o mpaux.o nchan.o packet.o radix.o random.o readpass.o rsa.o tildexpand.o ttymodes.o uidswap.o xmalloc.o SSHOBJS= ssh.o sshconnect.o log-client.o readconf.o clientloop.o -SSHDOBJS= sshd.o auth-rhosts.o auth-krb4.o auth-pam.o auth-passwd.o auth-rsa.o auth-rh-rsa.o pty.o log-server.o login.o servconf.o serverloop.o bsd-login.o md5crypt.o +SSHDOBJS= sshd.o auth-rhosts.o auth-krb4.o auth-pam.o auth-passwd.o auth-rsa.o auth-rh-rsa.o pty.o log-server.o login.o servconf.o serverloop.o bsd-login.o md5crypt.o session.o auth.o TROFFMAN = scp.1 ssh-add.1 ssh-agent.1 ssh-keygen.1 ssh.1 sshd.8 CATMAN = scp.0 ssh-add.0 ssh-agent.0 ssh-keygen.0 ssh.0 sshd.0 @@ -0,0 +1,606 @@ +/* + * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland + * All rights reserved + */ + +#include "includes.h" +RCSID("$OpenBSD: auth.c,v 1.1 2000/03/28 21:15:45 markus Exp $"); + +#include "xmalloc.h" +#include "rsa.h" +#include "ssh.h" +#include "pty.h" +#include "packet.h" +#include "buffer.h" +#include "cipher.h" +#include "mpaux.h" +#include "servconf.h" +#include "channels.h" +#include "match.h" + +#include "session.h" +#include "dispatch.h" + +/* import */ +extern ServerOptions options; +extern char *forced_command; + +/* + * Check if the user is allowed to log in via ssh. If user is listed in + * DenyUsers or user's primary group is listed in DenyGroups, false will + * be returned. If AllowUsers isn't empty and user isn't listed there, or + * if AllowGroups isn't empty and user isn't listed there, false will be + * returned. + * If the user's shell is not executable, false will be returned. + * Otherwise true is returned. + */ +static int +allowed_user(struct passwd * pw) +{ + struct stat st; + struct group *grp; + int i; +#ifdef WITH_AIXAUTHENTICATE + char *loginmsg; +#endif /* WITH_AIXAUTHENTICATE */ + + /* Shouldn't be called if pw is NULL, but better safe than sorry... */ + if (!pw) + return 0; + + /* deny if shell does not exists or is not executable */ + if (stat(pw->pw_shell, &st) != 0) + return 0; + if (!((st.st_mode & S_IFREG) && (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP)))) + return 0; + + /* Return false if user is listed in DenyUsers */ + if (options.num_deny_users > 0) { + if (!pw->pw_name) + return 0; + for (i = 0; i < options.num_deny_users; i++) + if (match_pattern(pw->pw_name, options.deny_users[i])) + return 0; + } + /* Return false if AllowUsers isn't empty and user isn't listed there */ + if (options.num_allow_users > 0) { + if (!pw->pw_name) + return 0; + for (i = 0; i < options.num_allow_users; i++) + if (match_pattern(pw->pw_name, options.allow_users[i])) + break; + /* i < options.num_allow_users iff we break for loop */ + if (i >= options.num_allow_users) + return 0; + } + /* Get the primary group name if we need it. Return false if it fails */ + if (options.num_deny_groups > 0 || options.num_allow_groups > 0) { + grp = getgrgid(pw->pw_gid); + if (!grp) + return 0; + + /* Return false if user's group is listed in DenyGroups */ + if (options.num_deny_groups > 0) { + if (!grp->gr_name) + return 0; + for (i = 0; i < options.num_deny_groups; i++) + if (match_pattern(grp->gr_name, options.deny_groups[i])) + return 0; + } + /* + * Return false if AllowGroups isn't empty and user's group + * isn't listed there + */ + if (options.num_allow_groups > 0) { + if (!grp->gr_name) + return 0; + for (i = 0; i < options.num_allow_groups; i++) + if (match_pattern(grp->gr_name, options.allow_groups[i])) + break; + /* i < options.num_allow_groups iff we break for + loop */ + if (i >= options.num_allow_groups) + return 0; + } + } + +#ifdef WITH_AIXAUTHENTICATE + if (loginrestrictions(pw->pw_name,S_LOGIN,NULL,&loginmsg) != 0) + return 0; +#endif /* WITH_AIXAUTHENTICATE */ + + /* We found no reason not to let this user try to log on... */ + return 1; +} + +/* + * convert ssh auth msg type into description + */ +char * +get_authname(int type) +{ + static char buf[1024]; + switch (type) { + case SSH_CMSG_AUTH_PASSWORD: + return "password"; + case SSH_CMSG_AUTH_RSA: + return "rsa"; + case SSH_CMSG_AUTH_RHOSTS_RSA: + return "rhosts-rsa"; + case SSH_CMSG_AUTH_RHOSTS: + return "rhosts"; +#ifdef KRB4 + case SSH_CMSG_AUTH_KERBEROS: + return "kerberos"; +#endif +#ifdef SKEY + case SSH_CMSG_AUTH_TIS_RESPONSE: + return "s/key"; +#endif + } + snprintf(buf, sizeof buf, "bad-auth-msg-%d", type); + return buf; +} + +#define AUTH_FAIL_MAX 6 +#define AUTH_FAIL_LOG (AUTH_FAIL_MAX/2) +#define AUTH_FAIL_MSG "Too many authentication failures for %.100s" + +/* + * The user does not exist or access is denied, + * but fake indication that authentication is needed. + */ +void +do_fake_authloop1(char *user) +{ + int attempt = 0; + + log("Faking authloop for illegal user %.200s from %.200s port %d", + user, + get_remote_ipaddr(), + get_remote_port()); + +#ifdef WITH_AIXAUTHENTICATE + if (strncmp(get_authname(type),"password", + strlen(get_authname(type))) == 0) + loginfailed(pw->pw_name,get_canonical_hostname(),"ssh"); +#endif /* WITH_AIXAUTHENTICATE */ + + /* Indicate that authentication is needed. */ + packet_start(SSH_SMSG_FAILURE); + packet_send(); + packet_write_wait(); + + /* + * Keep reading packets, and always respond with a failure. This is + * to avoid disclosing whether such a user really exists. + */ + for (attempt = 1;; attempt++) { + /* Read a packet. This will not return if the client disconnects. */ + int plen; +#ifndef SKEY + (void)packet_read(&plen); +#else /* SKEY */ + int type = packet_read(&plen); + unsigned int dlen; + char *password, *skeyinfo; + /* Try to send a fake s/key challenge. */ + if (options.skey_authentication == 1 && + (skeyinfo = skey_fake_keyinfo(user)) != NULL) { + password = NULL; + if (type == SSH_CMSG_AUTH_TIS) { + packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE); + packet_put_string(skeyinfo, strlen(skeyinfo)); + packet_send(); + packet_write_wait(); + continue; + } else if (type == SSH_CMSG_AUTH_PASSWORD && + options.password_authentication && + (password = packet_get_string(&dlen)) != NULL && + dlen == 5 && + strncasecmp(password, "s/key", 5) == 0 ) { + packet_send_debug(skeyinfo); + } + if (password != NULL) + xfree(password); + } +#endif + if (attempt > AUTH_FAIL_MAX) + packet_disconnect(AUTH_FAIL_MSG, user); + + /* + * Send failure. This should be indistinguishable from a + * failed authentication. + */ + packet_start(SSH_SMSG_FAILURE); + packet_send(); + packet_write_wait(); + } + /* NOTREACHED */ + abort(); +} + +/* + * read packets and try to authenticate local user *pw. + * return if authentication is successfull + */ +void +do_authloop(struct passwd * pw) +{ + int attempt = 0; + unsigned int bits; + RSA *client_host_key; + BIGNUM *n; + char *client_user = NULL, *password = NULL; + char user[1024]; + unsigned int dlen; + int plen, nlen, elen; + unsigned int ulen; + int type = 0; + void (*authlog) (const char *fmt,...) = verbose; + + /* Indicate that authentication is needed. */ + packet_start(SSH_SMSG_FAILURE); + packet_send(); + packet_write_wait(); + + for (attempt = 1;; attempt++) { + int authenticated = 0; + strlcpy(user, "", sizeof user); + + /* Get a packet from the client. */ + type = packet_read(&plen); + + /* Process the packet. */ + switch (type) { +#ifdef AFS + case SSH_CMSG_HAVE_KERBEROS_TGT: + if (!options.kerberos_tgt_passing) { + /* packet_get_all(); */ + verbose("Kerberos tgt passing disabled."); + break; + } else { + /* Accept Kerberos tgt. */ + char *tgt = packet_get_string(&dlen); + packet_integrity_check(plen, 4 + dlen, type); + if (!auth_kerberos_tgt(pw, tgt)) + verbose("Kerberos tgt REFUSED for %s", pw->pw_name); + xfree(tgt); + } + continue; + + case SSH_CMSG_HAVE_AFS_TOKEN: + if (!options.afs_token_passing || !k_hasafs()) { + /* packet_get_all(); */ + verbose("AFS token passing disabled."); + break; + } else { + /* Accept AFS token. */ + char *token_string = packet_get_string(&dlen); + packet_integrity_check(plen, 4 + dlen, type); + if (!auth_afs_token(pw, token_string)) + verbose("AFS token REFUSED for %s", pw->pw_name); + xfree(token_string); + } + continue; +#endif /* AFS */ +#ifdef KRB4 + case SSH_CMSG_AUTH_KERBEROS: + if (!options.kerberos_authentication) { + /* packet_get_all(); */ + verbose("Kerberos authentication disabled."); + break; + } else { + /* Try Kerberos v4 authentication. */ + KTEXT_ST auth; + char *tkt_user = NULL; + char *kdata = packet_get_string((unsigned int *) &auth.length); + packet_integrity_check(plen, 4 + auth.length, type); + + if (auth.length < MAX_KTXT_LEN) + memcpy(auth.dat, kdata, auth.length); + xfree(kdata); + + authenticated = auth_krb4(pw->pw_name, &auth, &tkt_user); + + if (authenticated) { + snprintf(user, sizeof user, " tktuser %s", tkt_user); + xfree(tkt_user); + } + } + break; +#endif /* KRB4 */ + + case SSH_CMSG_AUTH_RHOSTS: + if (!options.rhosts_authentication) { + verbose("Rhosts authentication disabled."); + break; + } + /* + * Get client user name. Note that we just have to + * trust the client; this is one reason why rhosts + * authentication is insecure. (Another is + * IP-spoofing on a local network.) + */ + client_user = packet_get_string(&ulen); + packet_integrity_check(plen, 4 + ulen, type); + + /* Try to authenticate using /etc/hosts.equiv and + .rhosts. */ + authenticated = auth_rhosts(pw, client_user); + + snprintf(user, sizeof user, " ruser %s", client_user); + break; + + case SSH_CMSG_AUTH_RHOSTS_RSA: + if (!options.rhosts_rsa_authentication) { + verbose("Rhosts with RSA authentication disabled."); + break; + } + /* + * Get client user name. Note that we just have to + * trust the client; root on the client machine can + * claim to be any user. + */ + client_user = packet_get_string(&ulen); + + /* Get the client host key. */ + client_host_key = RSA_new(); + if (client_host_key == NULL) + fatal("RSA_new failed"); + client_host_key->e = BN_new(); + client_host_key->n = BN_new(); + if (client_host_key->e == NULL || client_host_key->n == NULL) + fatal("BN_new failed"); + bits = packet_get_int(); + packet_get_bignum(client_host_key->e, &elen); + packet_get_bignum(client_host_key->n, &nlen); + + if (bits != BN_num_bits(client_host_key->n)) + error("Warning: keysize mismatch for client_host_key: " + "actual %d, announced %d", BN_num_bits(client_host_key->n), bits); + packet_integrity_check(plen, (4 + ulen) + 4 + elen + nlen, type); + + authenticated = auth_rhosts_rsa(pw, client_user, client_host_key); + RSA_free(client_host_key); + + snprintf(user, sizeof user, " ruser %s", client_user); + break; + + case SSH_CMSG_AUTH_RSA: + if (!options.rsa_authentication) { + verbose("RSA authentication disabled."); + break; + } + /* RSA authentication requested. */ + n = BN_new(); + packet_get_bignum(n, &nlen); + packet_integrity_check(plen, nlen, type); + authenticated = auth_rsa(pw, n); + BN_clear_free(n); + break; + + case SSH_CMSG_AUTH_PASSWORD: + if (!options.password_authentication) { + verbose("Password authentication disabled."); + break; + } + /* + * Read user password. It is in plain text, but was + * transmitted over the encrypted channel so it is + * not visible to an outside observer. + */ + password = packet_get_string(&dlen); + packet_integrity_check(plen, 4 + dlen, type); + +#ifdef USE_PAM + /* Do PAM auth with password */ + authenticated = auth_pam_password(pw, password); +#else /* USE_PAM */ + /* Try authentication with the password. */ + authenticated = auth_password(pw, password); +#endif /* USE_PAM */ + memset(password, 0, strlen(password)); + xfree(password); + break; + +#ifdef SKEY + case SSH_CMSG_AUTH_TIS: + debug("rcvd SSH_CMSG_AUTH_TIS"); + if (options.skey_authentication == 1) { + char *skeyinfo = skey_keyinfo(pw->pw_name); + if (skeyinfo == NULL) { + debug("generating fake skeyinfo for %.100s.", pw->pw_name); + skeyinfo = skey_fake_keyinfo(pw->pw_name); + } + if (skeyinfo != NULL) { + /* we send our s/key- in tis-challenge messages */ + debug("sending challenge '%s'", skeyinfo); + packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE); + packet_put_string(skeyinfo, strlen(skeyinfo)); + packet_send(); + packet_write_wait(); + continue; + } + } + break; + case SSH_CMSG_AUTH_TIS_RESPONSE: + debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE"); + if (options.skey_authentication == 1) { + char *response = packet_get_string(&dlen); + debug("skey response == '%s'", response); + packet_integrity_check(plen, 4 + dlen, type); + authenticated = (skey_haskey(pw->pw_name) == 0 && + skey_passcheck(pw->pw_name, response) != -1); + xfree(response); + } + break; +#else + case SSH_CMSG_AUTH_TIS: + /* TIS Authentication is unsupported */ + log("TIS authentication unsupported."); + break; +#endif + + default: + /* + * Any unknown messages will be ignored (and failure + * returned) during authentication. + */ + log("Unknown message during authentication: type %d", type); + break; + } + + /* + * Check if the user is logging in as root and root logins + * are disallowed. + * Note that root login is allowed for forced commands. + */ + if (authenticated && pw->pw_uid == 0 && !options.permit_root_login) { + if (forced_command) { + log("Root login accepted for forced command."); + } else { + authenticated = 0; + log("ROOT LOGIN REFUSED FROM %.200s", + get_canonical_hostname()); + } + } + + /* Raise logging level */ + if (authenticated || + attempt == AUTH_FAIL_LOG || + type == SSH_CMSG_AUTH_PASSWORD) + authlog = log; + + authlog("%s %s for %.200s from %.200s port %d%s", + authenticated ? "Accepted" : "Failed", + get_authname(type), + pw->pw_uid == 0 ? "ROOT" : pw->pw_name, + get_remote_ipaddr(), + get_remote_port(), + user); + +#ifdef USE_PAM + if (authenticated) { + if (!do_pam_account(pw->pw_name, client_user)) { + if (client_user != NULL) { + xfree(client_user); + client_user = NULL; + } + do_fake_authloop1(pw->pw_name); + } + return; + } +#else /* USE_PAM */ + if (authenticated) { + return; + } +#endif /* USE_PAM */ + + if (client_user != NULL) { + xfree(client_user); + client_user = NULL; + } + + if (attempt > AUTH_FAIL_MAX) + packet_disconnect(AUTH_FAIL_MSG, pw->pw_name); + + /* Send a message indicating that the authentication attempt failed. */ + packet_start(SSH_SMSG_FAILURE); + packet_send(); + packet_write_wait(); + } +} + +/* + * Performs authentication of an incoming connection. Session key has already + * been exchanged and encryption is enabled. + */ +void +do_authentication() +{ + struct passwd *pw, pwcopy; + int plen; + unsigned int ulen; + char *user; +#ifdef WITH_AIXAUTHENTICATE + char *loginmsg; +#endif /* WITH_AIXAUTHENTICATE */ + + /* Get the name of the user that we wish to log in as. */ + packet_read_expect(&plen, SSH_CMSG_USER); + + /* Get the user name. */ + user = packet_get_string(&ulen); + packet_integrity_check(plen, (4 + ulen), SSH_CMSG_USER); + + setproctitle("%s", user); + +#ifdef AFS + /* If machine has AFS, set process authentication group. */ + if (k_hasafs()) { + k_setpag(); + k_unlog(); + } +#endif /* AFS */ + + /* Verify that the user is a valid user. */ + pw = getpwnam(user); + if (!pw || !allowed_user(pw)) + do_fake_authloop1(user); + xfree(user); + + /* Take a copy of the returned structure. */ + memset(&pwcopy, 0, sizeof(pwcopy)); + pwcopy.pw_name = xstrdup(pw->pw_name); + pwcopy.pw_passwd = xstrdup(pw->pw_passwd); + pwcopy.pw_uid = pw->pw_uid; + pwcopy.pw_gid = pw->pw_gid; + pwcopy.pw_dir = xstrdup(pw->pw_dir); + pwcopy.pw_shell = xstrdup(pw->pw_shell); + pw = &pwcopy; + +#ifdef USE_PAM + start_pam(pw); +#endif + + /* + * If we are not running as root, the user must have the same uid as + * the server. + */ + if (getuid() != 0 && pw->pw_uid != getuid()) + packet_disconnect("Cannot change user when server not running as root."); + + debug("Attempting authentication for %.100s.", pw->pw_name); + + /* If the user has no password, accept authentication immediately. */ + if (options.password_authentication && +#ifdef KRB4 + (!options.kerberos_authentication || options.kerberos_or_local_passwd) && +#endif /* KRB4 */ +#ifdef USE_PAM + auth_pam_password(pw, "")) { +#else /* USE_PAM */ + auth_password(pw, "")) { +#endif /* USE_PAM */ + /* Authentication with empty password succeeded. */ + log("Login for user %s from %.100s, accepted without authentication.", + pw->pw_name, get_remote_ipaddr()); + } else { + /* Loop until the user has been authenticated or the + connection is closed, do_authloop() returns only if + authentication is successfull */ + do_authloop(pw); + } + + /* The user has been authenticated and accepted. */ +#ifdef WITH_AIXAUTHENTICATE + loginsuccess(user,get_canonical_hostname(),"ssh",&loginmsg); +#endif /* WITH_AIXAUTHENTICATE */ + packet_start(SSH_SMSG_SUCCESS); + packet_send(); + packet_write_wait(); + + /* Perform session preparation. */ + do_authenticated(pw); +} @@ -0,0 +1,6 @@ +#ifndef AUTH_H +#define AUTH_H + +void do_authentication(void); + +#endif @@ -12,10 +12,12 @@ * Auxiliary functions for storing and retrieving various data types to/from * Buffers. * + * SSH2 packet format added by Markus Friedl + * */ #include "includes.h" -RCSID("$Id: bufaux.c,v 1.8 2000/03/17 12:40:15 damien Exp $"); +RCSID("$Id: bufaux.c,v 1.9 2000/04/01 01:09:23 damien Exp $"); #include "ssh.h" @@ -83,6 +85,50 @@ buffer_get_bignum(Buffer *buffer, BIGNUM *value) } /* + * Stores an BIGNUM in the buffer in SSH2 format. + */ +void +buffer_put_bignum2(Buffer *buffer, BIGNUM *value) +{ + int bytes = BN_num_bytes(value) + 1; + unsigned char *buf = xmalloc(bytes); + int oi; + int hasnohigh = 0; + buf[0] = '\0'; + /* Get the value of in binary */ + oi = BN_bn2bin(value, buf+1); + if (oi != bytes-1) + fatal("buffer_put_bignum: BN_bn2bin() failed: oi %d != bin_size %d", + oi, bytes); + hasnohigh = (buf[1] & 0x80) ? 0 : 1; + if (value->neg) { + /**XXX should be two's-complement */ + int i, carry; + unsigned char *uc = buf; + log("negativ!"); + for(i = bytes-1, carry = 1; i>=0; i--) { + uc[i] ^= 0xff; + if(carry) + carry = !++uc[i]; + } + } + buffer_put_string(buffer, buf+hasnohigh, bytes-hasnohigh); + memset(buf, 0, bytes); + xfree(buf); +} + +int +buffer_get_bignum2(Buffer *buffer, BIGNUM *value) +{ + /**XXX should be two's-complement */ + int len; + unsigned char *bin = (unsigned char *)buffer_get_string(buffer, (unsigned int *)&len); + BN_bin2bn(bin, len, value); + xfree(bin); + return len; +} + +/* * Returns an integer from the buffer (4 bytes, msb first). */ unsigned int @@ -142,6 +188,11 @@ buffer_put_string(Buffer *buffer, const void *buf, unsigned int len) buffer_put_int(buffer, len); buffer_append(buffer, buf, len); } +void +buffer_put_cstring(Buffer *buffer, const char *s) +{ + buffer_put_string(buffer, s, strlen(s)); +} /* * Returns a character from the buffer (0 - 255). @@ -11,7 +11,7 @@ * */ -/* RCSID("$Id: bufaux.h,v 1.3 1999/11/25 00:54:58 damien Exp $"); */ +/* RCSID("$Id: bufaux.h,v 1.4 2000/04/01 01:09:23 damien Exp $"); */ #ifndef BUFAUX_H #define BUFAUX_H @@ -23,9 +23,11 @@ * by (bits+7)/8 bytes of binary data, msb first. */ void buffer_put_bignum(Buffer * buffer, BIGNUM * value); +void buffer_put_bignum2(Buffer * buffer, BIGNUM * value); /* Retrieves an BIGNUM from the buffer. */ int buffer_get_bignum(Buffer * buffer, BIGNUM * value); +int buffer_get_bignum2(Buffer *buffer, BIGNUM * value); /* Returns an integer from the buffer (4 bytes, msb first). */ unsigned int buffer_get_int(Buffer * buffer); @@ -51,5 +53,6 @@ char *buffer_get_string(Buffer * buffer, unsigned int *length_ptr); /* Stores and arbitrary binary string in the buffer. */ void buffer_put_string(Buffer * buffer, const void *buf, unsigned int len); +void buffer_put_cstring(Buffer *buffer, const char *s); #endif /* BUFAUX_H */ diff --git a/channels.c b/channels.c index e60ecc614..b87ff9f4f 100644 --- a/channels.c +++ b/channels.c @@ -16,7 +16,7 @@ */ #include "includes.h" -RCSID("$Id: channels.c,v 1.19 2000/03/17 12:40:15 damien Exp $"); +RCSID("$Id: channels.c,v 1.20 2000/04/01 01:09:23 damien Exp $"); #include "ssh.h" #include "packet.h" @@ -37,6 +37,10 @@ RCSID("$Id: channels.c,v 1.19 2000/03/17 12:40:15 damien Exp $"); /* Max len of agent socket */ #define MAX_SOCKET_NAME 100 +/* default buffer for tcp-fwd-channel */ +#define CHAN_WINDOW_DEFAULT (8*1024) +#define CHAN_PACKET_DEFAULT (CHAN_WINDOW_DEFAULT/2) + /* * Pointer to an array containing all allocated channels. The array is * dynamically extended as needed. @@ -81,8 +85,9 @@ unsigned int x11_fake_data_len; * network (which might be behind a firewall). */ typedef struct { - char *host; /* Host name. */ - u_short port; /* Port number. */ + char *host_to_connect; /* Connect to 'host'. */ + u_short port_to_connect; /* Connect to 'port'. */ + u_short listen_port; /* Remote side should listen port number. */ } ForwardPermission; /* List of all permitted host/port pairs to connect. */ @@ -119,20 +124,43 @@ channel_permit_all_opens() all_opens_permitted = 1; } +/* lookup channel by id */ + +Channel * +channel_lookup(int id) +{ + Channel *c; + if (id < 0 && id > channels_alloc) { + log("channel_lookup: %d: bad id", id); + return NULL; + } + c = &channels[id]; + if (c->type == SSH_CHANNEL_FREE) { + log("channel_lookup: %d: bad id: channel free", id); + return NULL; + } + return c; +} + /* * Allocate a new channel object and set its type and socket. This will cause * remote_name to be freed. */ int -channel_allocate(int type, int sock, char *remote_name) +channel_new(char *ctype, int type, int rfd, int wfd, int efd, + int window, int maxpack, int extended_usage, char *remote_name) { int i, found; Channel *c; /* Update the maximum file descriptor value. */ - if (sock > channel_max_fd_value) - channel_max_fd_value = sock; + if (rfd > channel_max_fd_value) + channel_max_fd_value = rfd; + if (wfd > channel_max_fd_value) + channel_max_fd_value = wfd; + if (efd > channel_max_fd_value) + channel_max_fd_value = efd; /* XXX set close-on-exec -markus */ /* Do initial allocation if this is the first call. */ @@ -167,388 +195,514 @@ channel_allocate(int type, int sock, char *remote_name) c = &channels[found]; buffer_init(&c->input); buffer_init(&c->output); + buffer_init(&c->extended); chan_init_iostates(c); c->self = found; c->type = type; - c->sock = sock; + c->ctype = ctype; + c->local_window = window; + c->local_window_max = window; + c->local_consumed = 0; + c->local_maxpacket = maxpack; + c->remote_window = 0; + c->remote_maxpacket = 0; + c->rfd = rfd; + c->wfd = wfd; + c->sock = (rfd == wfd) ? rfd : -1; + c->efd = efd; + c->extended_usage = extended_usage; c->remote_id = -1; c->remote_name = remote_name; + c->remote_window = 0; + c->remote_maxpacket = 0; + c->cb_fn = NULL; + c->cb_arg = NULL; + c->cb_event = 0; + c->dettach_user = NULL; debug("channel %d: new [%s]", found, remote_name); return found; } +int +channel_allocate(int type, int sock, char *remote_name) +{ + return channel_new("", type, sock, sock, -1, 0, 0, 0, remote_name); +} /* Free the channel and close its socket. */ void -channel_free(int channel) +channel_free(int id) { - if (channel < 0 || channel >= channels_alloc || - channels[channel].type == SSH_CHANNEL_FREE) - packet_disconnect("channel free: bad local channel %d", channel); - - if (compat13) - shutdown(channels[channel].sock, SHUT_RDWR); - close(channels[channel].sock); - buffer_free(&channels[channel].input); - buffer_free(&channels[channel].output); - channels[channel].type = SSH_CHANNEL_FREE; - if (channels[channel].remote_name) { - xfree(channels[channel].remote_name); - channels[channel].remote_name = NULL; + Channel *c = channel_lookup(id); + if (c == NULL) + packet_disconnect("channel free: bad local channel %d", id); + debug("channel_free: channel %d: status: %s", id, channel_open_message()); + if (c->sock != -1) { + shutdown(c->sock, SHUT_RDWR); + close(c->sock); + } + buffer_free(&c->input); + buffer_free(&c->output); + buffer_free(&c->extended); + c->type = SSH_CHANNEL_FREE; + if (c->remote_name) { + xfree(c->remote_name); + c->remote_name = NULL; } } /* - * This is called just before select() to add any bits relevant to channels - * in the select bitmasks. + * 'channel_pre*' are called just before select() to add any bits relevant to + * channels in the select bitmasks. + */ +/* + * 'channel_post*': perform any appropriate operations for channels which + * have events pending. */ +typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset); +chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE]; +chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE]; -void -channel_prepare_select(fd_set * readset, fd_set * writeset) +void +channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset) { - int i; - Channel *ch; - unsigned char *ucp; - unsigned int proto_len, data_len; + FD_SET(c->sock, readset); +} - for (i = 0; i < channels_alloc; i++) { - ch = &channels[i]; -redo: - switch (ch->type) { - case SSH_CHANNEL_X11_LISTENER: - case SSH_CHANNEL_PORT_LISTENER: - case SSH_CHANNEL_AUTH_SOCKET: - FD_SET(ch->sock, readset); - break; +void +channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset) +{ + if (buffer_len(&c->input) < packet_get_maxsize()) + FD_SET(c->sock, readset); + if (buffer_len(&c->output) > 0) + FD_SET(c->sock, writeset); +} - case SSH_CHANNEL_OPEN: - if (compat13) { - if (buffer_len(&ch->input) < packet_get_maxsize()) - FD_SET(ch->sock, readset); - if (buffer_len(&ch->output) > 0) - FD_SET(ch->sock, writeset); - break; - } - /* test whether sockets are 'alive' for read/write */ - if (ch->istate == CHAN_INPUT_OPEN) - if (buffer_len(&ch->input) < packet_get_maxsize()) - FD_SET(ch->sock, readset); - if (ch->ostate == CHAN_OUTPUT_OPEN || - ch->ostate == CHAN_OUTPUT_WAIT_DRAIN) { - if (buffer_len(&ch->output) > 0) { - FD_SET(ch->sock, writeset); - } else if (ch->ostate == CHAN_OUTPUT_WAIT_DRAIN) { - chan_obuf_empty(ch); - } - } - break; +void +channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset) +{ + /* test whether sockets are 'alive' for read/write */ + if (c->istate == CHAN_INPUT_OPEN) + if (buffer_len(&c->input) < packet_get_maxsize()) + FD_SET(c->sock, readset); + if (c->ostate == CHAN_OUTPUT_OPEN || + c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { + if (buffer_len(&c->output) > 0) { + FD_SET(c->sock, writeset); + } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { + chan_obuf_empty(c); + } + } +} - case SSH_CHANNEL_INPUT_DRAINING: - if (!compat13) - fatal("cannot happen: IN_DRAIN"); - if (buffer_len(&ch->input) == 0) { - packet_start(SSH_MSG_CHANNEL_CLOSE); - packet_put_int(ch->remote_id); - packet_send(); - ch->type = SSH_CHANNEL_CLOSED; - debug("Closing channel %d after input drain.", ch->self); - break; - } - break; +void +channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset) +{ + if (buffer_len(&c->input) == 0) { + packet_start(SSH_MSG_CHANNEL_CLOSE); + packet_put_int(c->remote_id); + packet_send(); + c->type = SSH_CHANNEL_CLOSED; + debug("Closing channel %d after input drain.", c->self); + } +} - case SSH_CHANNEL_OUTPUT_DRAINING: - if (!compat13) - fatal("cannot happen: OUT_DRAIN"); - if (buffer_len(&ch->output) == 0) { - channel_free(i); - break; - } - FD_SET(ch->sock, writeset); - break; +void +channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset) +{ + if (buffer_len(&c->output) == 0) + channel_free(c->self); + else + FD_SET(c->sock, writeset); +} - case SSH_CHANNEL_X11_OPEN: - /* - * This is a special state for X11 authentication - * spoofing. An opened X11 connection (when - * authentication spoofing is being done) remains in - * this state until the first packet has been - * completely read. The authentication data in that - * packet is then substituted by the real data if it - * matches the fake data, and the channel is put into - * normal mode. - */ - /* Check if the fixed size part of the packet is in buffer. */ - if (buffer_len(&ch->output) < 12) - break; +/* + * This is a special state for X11 authentication spoofing. An opened X11 + * connection (when authentication spoofing is being done) remains in this + * state until the first packet has been completely read. The authentication + * data in that packet is then substituted by the real data if it matches the + * fake data, and the channel is put into normal mode. + */ +int +x11_open_helper(Channel *c) +{ + unsigned char *ucp; + unsigned int proto_len, data_len; - /* Parse the lengths of variable-length fields. */ - ucp = (unsigned char *) buffer_ptr(&ch->output); - if (ucp[0] == 0x42) { /* Byte order MSB first. */ - proto_len = 256 * ucp[6] + ucp[7]; - data_len = 256 * ucp[8] + ucp[9]; - } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */ - proto_len = ucp[6] + 256 * ucp[7]; - data_len = ucp[8] + 256 * ucp[9]; - } else { - debug("Initial X11 packet contains bad byte order byte: 0x%x", - ucp[0]); - ch->type = SSH_CHANNEL_OPEN; - goto reject; - } + /* Check if the fixed size part of the packet is in buffer. */ + if (buffer_len(&c->output) < 12) + return 0; + + /* Parse the lengths of variable-length fields. */ + ucp = (unsigned char *) buffer_ptr(&c->output); + if (ucp[0] == 0x42) { /* Byte order MSB first. */ + proto_len = 256 * ucp[6] + ucp[7]; + data_len = 256 * ucp[8] + ucp[9]; + } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */ + proto_len = ucp[6] + 256 * ucp[7]; + data_len = ucp[8] + 256 * ucp[9]; + } else { + debug("Initial X11 packet contains bad byte order byte: 0x%x", + ucp[0]); + return -1; + } - /* Check if the whole packet is in buffer. */ - if (buffer_len(&ch->output) < - 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3)) - break; + /* Check if the whole packet is in buffer. */ + if (buffer_len(&c->output) < + 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3)) + return 0; - /* Check if authentication protocol matches. */ - if (proto_len != strlen(x11_saved_proto) || - memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) { - debug("X11 connection uses different authentication protocol."); - ch->type = SSH_CHANNEL_OPEN; - goto reject; - } - /* Check if authentication data matches our fake data. */ - if (data_len != x11_fake_data_len || - memcmp(ucp + 12 + ((proto_len + 3) & ~3), - x11_fake_data, x11_fake_data_len) != 0) { - debug("X11 auth data does not match fake data."); - ch->type = SSH_CHANNEL_OPEN; - goto reject; - } - /* Check fake data length */ - if (x11_fake_data_len != x11_saved_data_len) { - error("X11 fake_data_len %d != saved_data_len %d", - x11_fake_data_len, x11_saved_data_len); - ch->type = SSH_CHANNEL_OPEN; - goto reject; - } - /* - * Received authentication protocol and data match - * our fake data. Substitute the fake data with real - * data. - */ - memcpy(ucp + 12 + ((proto_len + 3) & ~3), - x11_saved_data, x11_saved_data_len); + /* Check if authentication protocol matches. */ + if (proto_len != strlen(x11_saved_proto) || + memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) { + debug("X11 connection uses different authentication protocol."); + return -1; + } + /* Check if authentication data matches our fake data. */ + if (data_len != x11_fake_data_len || + memcmp(ucp + 12 + ((proto_len + 3) & ~3), + x11_fake_data, x11_fake_data_len) != 0) { + debug("X11 auth data does not match fake data."); + return -1; + } + /* Check fake data length */ + if (x11_fake_data_len != x11_saved_data_len) { + error("X11 fake_data_len %d != saved_data_len %d", + x11_fake_data_len, x11_saved_data_len); + return -1; + } + /* + * Received authentication protocol and data match + * our fake data. Substitute the fake data with real + * data. + */ + memcpy(ucp + 12 + ((proto_len + 3) & ~3), + x11_saved_data, x11_saved_data_len); + return 1; +} - /* Start normal processing for the channel. */ - ch->type = SSH_CHANNEL_OPEN; - goto redo; +void +channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset) +{ + int ret = x11_open_helper(c); + if (ret == 1) { + /* Start normal processing for the channel. */ + c->type = SSH_CHANNEL_OPEN; + } else if (ret == -1) { + /* + * We have received an X11 connection that has bad + * authentication information. + */ + log("X11 connection rejected because of wrong authentication.\r\n"); + buffer_clear(&c->input); + buffer_clear(&c->output); + close(c->sock); + c->sock = -1; + c->type = SSH_CHANNEL_CLOSED; + packet_start(SSH_MSG_CHANNEL_CLOSE); + packet_put_int(c->remote_id); + packet_send(); + } +} - reject: - /* - * We have received an X11 connection that has bad - * authentication information. - */ - log("X11 connection rejected because of wrong authentication.\r\n"); - buffer_clear(&ch->input); - buffer_clear(&ch->output); - if (compat13) { - close(ch->sock); - ch->sock = -1; - ch->type = SSH_CHANNEL_CLOSED; - packet_start(SSH_MSG_CHANNEL_CLOSE); - packet_put_int(ch->remote_id); - packet_send(); - } else { - debug("X11 rejected %d i%d/o%d", ch->self, ch->istate, ch->ostate); - chan_read_failed(ch); - chan_write_failed(ch); - debug("X11 rejected %d i%d/o%d", ch->self, ch->istate, ch->ostate); - } - break; +void +channel_pre_x11_open_15(Channel *c, fd_set * readset, fd_set * writeset) +{ + int ret = x11_open_helper(c); + if (ret == 1) { + c->type = SSH_CHANNEL_OPEN; + } else if (ret == -1) { + debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate); + chan_read_failed(c); + chan_write_failed(c); + debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate); + } +} - case SSH_CHANNEL_FREE: - default: - continue; +/* This is our fake X11 server socket. */ +void +channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset) +{ + struct sockaddr addr; + int newsock, newch; + socklen_t addrlen; + char buf[16384], *remote_hostname; + + if (FD_ISSET(c->sock, readset)) { + debug("X11 connection requested."); + addrlen = sizeof(addr); + newsock = accept(c->sock, &addr, &addrlen); + if (newsock < 0) { + error("accept: %.100s", strerror(errno)); + return; } + remote_hostname = get_remote_hostname(newsock); + snprintf(buf, sizeof buf, "X11 connection from %.200s port %d", + remote_hostname, get_peer_port(newsock)); + xfree(remote_hostname); + newch = channel_allocate(SSH_CHANNEL_OPENING, newsock, + xstrdup(buf)); + packet_start(SSH_SMSG_X11_OPEN); + packet_put_int(newch); + if (have_hostname_in_open) + packet_put_string(buf, strlen(buf)); + packet_send(); } } /* - * After select, perform any appropriate operations for channels which have - * events pending. + * This socket is listening for connections to a forwarded TCP/IP port. */ +void +channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset) +{ + struct sockaddr addr; + int newsock, newch; + socklen_t addrlen; + char buf[1024], *remote_hostname; + int remote_port; + + if (FD_ISSET(c->sock, readset)) { + debug("Connection to port %d forwarding " + "to %.100s port %d requested.", + c->listening_port, c->path, c->host_port); + addrlen = sizeof(addr); + newsock = accept(c->sock, &addr, &addrlen); + if (newsock < 0) { + error("accept: %.100s", strerror(errno)); + return; + } + remote_hostname = get_remote_hostname(newsock); + remote_port = get_peer_port(newsock); + snprintf(buf, sizeof buf, + "listen port %d for %.100s port %d, " + "connect from %.200s port %d", + c->listening_port, c->path, c->host_port, + remote_hostname, remote_port); + newch = channel_new("direct-tcpip", + SSH_CHANNEL_OPENING, newsock, newsock, -1, + c->local_window_max, c->local_maxpacket, + 0, xstrdup(buf)); + + packet_start(SSH_MSG_PORT_OPEN); + packet_put_int(newch); + packet_put_string(c->path, strlen(c->path)); + packet_put_int(c->host_port); + if (have_hostname_in_open) { + packet_put_string(buf, strlen(buf)); + } + packet_send(); + xfree(remote_hostname); + } +} -void -channel_after_select(fd_set * readset, fd_set * writeset) +/* + * This is the authentication agent socket listening for connections from + * clients. + */ +void +channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset) { struct sockaddr addr; - int newsock, i, newch, len; + int newsock, newch; socklen_t addrlen; - Channel *ch; - char buf[16384], *remote_hostname; - /* Loop over all channels... */ - for (i = 0; i < channels_alloc; i++) { - ch = &channels[i]; - switch (ch->type) { - case SSH_CHANNEL_X11_LISTENER: - /* This is our fake X11 server socket. */ - if (FD_ISSET(ch->sock, readset)) { - debug("X11 connection requested."); - addrlen = sizeof(addr); - newsock = accept(ch->sock, &addr, &addrlen); - if (newsock < 0) { - error("accept: %.100s", strerror(errno)); - break; - } - remote_hostname = get_remote_hostname(newsock); - snprintf(buf, sizeof buf, "X11 connection from %.200s port %d", - remote_hostname, get_peer_port(newsock)); - xfree(remote_hostname); - newch = channel_allocate(SSH_CHANNEL_OPENING, newsock, - xstrdup(buf)); - packet_start(SSH_SMSG_X11_OPEN); - packet_put_int(newch); - if (have_hostname_in_open) - packet_put_string(buf, strlen(buf)); - packet_send(); - } - break; + if (FD_ISSET(c->sock, readset)) { + addrlen = sizeof(addr); + newsock = accept(c->sock, &addr, &addrlen); + if (newsock < 0) { + error("accept from auth socket: %.100s", strerror(errno)); + return; + } + newch = channel_allocate(SSH_CHANNEL_OPENING, newsock, + xstrdup("accepted auth socket")); + packet_start(SSH_SMSG_AGENT_OPEN); + packet_put_int(newch); + packet_send(); + } +} - case SSH_CHANNEL_PORT_LISTENER: - /* - * This socket is listening for connections to a - * forwarded TCP/IP port. - */ - if (FD_ISSET(ch->sock, readset)) { - debug("Connection to port %d forwarding to %.100s port %d requested.", - ch->listening_port, ch->path, ch->host_port); - addrlen = sizeof(addr); - newsock = accept(ch->sock, &addr, &addrlen); - if (newsock < 0) { - error("accept: %.100s", strerror(errno)); - break; - } - remote_hostname = get_remote_hostname(newsock); - snprintf(buf, sizeof buf, "listen port %d for %.100s port %d, connect from %.200s port %d", - ch->listening_port, ch->path, ch->host_port, - remote_hostname, get_peer_port(newsock)); - xfree(remote_hostname); - newch = channel_allocate(SSH_CHANNEL_OPENING, newsock, - xstrdup(buf)); - packet_start(SSH_MSG_PORT_OPEN); - packet_put_int(newch); - packet_put_string(ch->path, strlen(ch->path)); - packet_put_int(ch->host_port); - if (have_hostname_in_open) - packet_put_string(buf, strlen(buf)); - packet_send(); +int +channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset) +{ + char buf[16*1024]; + int len; + + if (c->rfd != -1 && + FD_ISSET(c->rfd, readset)) { + len = read(c->rfd, buf, sizeof(buf)); + if (len <= 0) { + debug("channel %d: read<0 rfd %d len %d", + c->self, c->rfd, len); + if (compat13) { + buffer_consume(&c->output, buffer_len(&c->output)); + c->type = SSH_CHANNEL_INPUT_DRAINING; + debug("Channel %d status set to input draining.", c->self); + } else { + chan_read_failed(c); } - break; - - case SSH_CHANNEL_AUTH_SOCKET: - /* - * This is the authentication agent socket listening - * for connections from clients. - */ - if (FD_ISSET(ch->sock, readset)) { - addrlen = sizeof(addr); - newsock = accept(ch->sock, &addr, &addrlen); - if (newsock < 0) { - error("accept from auth socket: %.100s", strerror(errno)); - break; - } - newch = channel_allocate(SSH_CHANNEL_OPENING, newsock, - xstrdup("accepted auth socket")); - packet_start(SSH_SMSG_AGENT_OPEN); - packet_put_int(newch); - packet_send(); + return -1; + } + buffer_append(&c->input, buf, len); + } + return 1; +} +int +channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset) +{ + int len; + + /* Send buffered output data to the socket. */ + if (c->wfd != -1 && + FD_ISSET(c->wfd, writeset) && + buffer_len(&c->output) > 0) { + len = write(c->wfd, buffer_ptr(&c->output), + buffer_len(&c->output)); + if (len <= 0) { + if (compat13) { + buffer_consume(&c->output, buffer_len(&c->output)); + debug("Channel %d status set to input draining.", c->self); + c->type = SSH_CHANNEL_INPUT_DRAINING; + } else { + chan_write_failed(c); } - break; + return -1; + } + buffer_consume(&c->output, len); + } + return 1; +} - case SSH_CHANNEL_OPEN: - /* - * This is an open two-way communication channel. It - * is not of interest to us at this point what kind - * of data is being transmitted. - */ +void +channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset) +{ + channel_handle_rfd(c, readset, writeset); + channel_handle_wfd(c, readset, writeset); +} - /* - * Read available incoming data and append it to - * buffer; shutdown socket, if read or write failes - */ - if (FD_ISSET(ch->sock, readset)) { - len = read(ch->sock, buf, sizeof(buf)); - if (len <= 0) { - if (compat13) { - buffer_consume(&ch->output, buffer_len(&ch->output)); - ch->type = SSH_CHANNEL_INPUT_DRAINING; - debug("Channel %d status set to input draining.", i); - } else { - chan_read_failed(ch); - } - break; - } - buffer_append(&ch->input, buf, len); - } - /* Send buffered output data to the socket. */ - if (FD_ISSET(ch->sock, writeset) && buffer_len(&ch->output) > 0) { - len = write(ch->sock, buffer_ptr(&ch->output), - buffer_len(&ch->output)); - if (len <= 0) { - if (compat13) { - buffer_consume(&ch->output, buffer_len(&ch->output)); - debug("Channel %d status set to input draining.", i); - ch->type = SSH_CHANNEL_INPUT_DRAINING; - } else { - chan_write_failed(ch); - } - break; - } - buffer_consume(&ch->output, len); - } - break; +void +channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset) +{ + int len; + /* Send buffered output data to the socket. */ + if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) { + len = write(c->sock, buffer_ptr(&c->output), + buffer_len(&c->output)); + if (len <= 0) + buffer_consume(&c->output, buffer_len(&c->output)); + else + buffer_consume(&c->output, len); + } +} - case SSH_CHANNEL_OUTPUT_DRAINING: - if (!compat13) - fatal("cannot happen: OUT_DRAIN"); - /* Send buffered output data to the socket. */ - if (FD_ISSET(ch->sock, writeset) && buffer_len(&ch->output) > 0) { - len = write(ch->sock, buffer_ptr(&ch->output), - buffer_len(&ch->output)); - if (len <= 0) - buffer_consume(&ch->output, buffer_len(&ch->output)); - else - buffer_consume(&ch->output, len); - } - break; +void +channel_handler_init_13(void) +{ + channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13; + channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13; + channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; + channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; + channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; + channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining; + channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining; + + channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1; + channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; + channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; + channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; + channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13; +} - case SSH_CHANNEL_X11_OPEN: - case SSH_CHANNEL_FREE: - default: +void +channel_handler_init_15(void) +{ + channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15; + channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_15; + channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; + channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; + channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; + + channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; + channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; + channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; + channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1; +} + +void +channel_handler_init(void) +{ + int i; + for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) { + channel_pre[i] = NULL; + channel_post[i] = NULL; + } + if (compat13) + channel_handler_init_13(); + else + channel_handler_init_15(); +} + +void +channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset) +{ + static int did_init = 0; + int i; + Channel *c; + + if (!did_init) { + channel_handler_init(); + did_init = 1; + } + for (i = 0; i < channels_alloc; i++) { + c = &channels[i]; + if (c->type == SSH_CHANNEL_FREE) continue; - } + if (ftab[c->type] == NULL) + continue; + (*ftab[c->type])(c, readset, writeset); + if (!compat13) + chan_delete_if_full_closed(c); } } +void +channel_prepare_select(fd_set * readset, fd_set * writeset) +{ + channel_handler(channel_pre, readset, writeset); +} + +void +channel_after_select(fd_set * readset, fd_set * writeset) +{ + channel_handler(channel_post, readset, writeset); +} + /* If there is data to send to the connection, send some of it now. */ void channel_output_poll() { int len, i; - Channel *ch; + Channel *c; for (i = 0; i < channels_alloc; i++) { - ch = &channels[i]; + c = &channels[i]; /* We are only interested in channels that can have buffered incoming data. */ if (compat13) { - if (ch->type != SSH_CHANNEL_OPEN && - ch->type != SSH_CHANNEL_INPUT_DRAINING) + if (c->type != SSH_CHANNEL_OPEN && + c->type != SSH_CHANNEL_INPUT_DRAINING) continue; } else { - if (ch->type != SSH_CHANNEL_OPEN) + if (c->type != SSH_CHANNEL_OPEN) continue; - if (ch->istate != CHAN_INPUT_OPEN && - ch->istate != CHAN_INPUT_WAIT_DRAIN) + if (c->istate != CHAN_INPUT_OPEN && + c->istate != CHAN_INPUT_WAIT_DRAIN) continue; } /* Get the amount of buffered data for this channel. */ - len = buffer_len(&ch->input); + len = buffer_len(&c->input); if (len > 0) { /* Send some data for the other side over the secure connection. */ if (packet_is_interactive()) { @@ -556,22 +710,26 @@ channel_output_poll() len = 512; } else { /* Keep the packets at reasonable size. */ - if (len > packet_get_maxsize()/2) + if (len > packet_get_maxsize()) len = packet_get_maxsize()/2; } - packet_start(SSH_MSG_CHANNEL_DATA); - packet_put_int(ch->remote_id); - packet_put_string(buffer_ptr(&ch->input), len); - packet_send(); - buffer_consume(&ch->input, len); - } else if (ch->istate == CHAN_INPUT_WAIT_DRAIN) { + if (len > 0) { + packet_start(SSH_MSG_CHANNEL_DATA); + packet_put_int(c->remote_id); + packet_put_string(buffer_ptr(&c->input), len); + packet_send(); + buffer_consume(&c->input, len); + c->remote_window -= len; +debug("channel %d: send data len %d", c->self, len); + } + } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) { if (compat13) fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3"); /* * input-buffer is empty and read-socket shutdown: * tell peer, that we will not send more data: send IEOF */ - chan_ibuf_empty(ch); + chan_ibuf_empty(c); } } } @@ -583,35 +741,33 @@ channel_output_poll() */ void -channel_input_data(int payload_len) +channel_input_data(int type, int plen) { int id; char *data; unsigned int data_len; - Channel *ch; + Channel *c; /* Get the channel number and verify it. */ id = packet_get_int(); - if (id < 0 || id >= channels_alloc) + c = channel_lookup(id); + if (c == NULL) packet_disconnect("Received data for nonexistent channel %d.", id); - ch = &channels[id]; - - if (ch->type == SSH_CHANNEL_FREE) - packet_disconnect("Received data for free channel %d.", ch->self); /* Ignore any data for non-open channels (might happen on close) */ - if (ch->type != SSH_CHANNEL_OPEN && - ch->type != SSH_CHANNEL_X11_OPEN) + if (c->type != SSH_CHANNEL_OPEN && + c->type != SSH_CHANNEL_X11_OPEN) return; /* same for protocol 1.5 if output end is no longer open */ - if (!compat13 && ch->ostate != CHAN_OUTPUT_OPEN) + if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) return; /* Get the data. */ data = packet_get_string(&data_len); - packet_integrity_check(payload_len, 4 + 4 + data_len, SSH_MSG_CHANNEL_DATA); - buffer_append(&ch->output, data, data_len); + + packet_integrity_check(plen, 4 + 4 + data_len, SSH_MSG_CHANNEL_DATA); + buffer_append(&c->output, data, data_len); xfree(data); } @@ -624,45 +780,60 @@ int channel_not_very_much_buffered_data() { unsigned int i; - Channel *ch; + Channel *c; for (i = 0; i < channels_alloc; i++) { - ch = &channels[i]; - if (ch->type == SSH_CHANNEL_OPEN) { - if (buffer_len(&ch->input) > packet_get_maxsize()) + c = &channels[i]; + if (c->type == SSH_CHANNEL_OPEN) { + if (buffer_len(&c->input) > packet_get_maxsize()) { + debug("channel %d: big input buffer %d", + c->self, buffer_len(&c->input)); return 0; - if (buffer_len(&ch->output) > packet_get_maxsize()) + } + if (buffer_len(&c->output) > packet_get_maxsize()) { + debug("channel %d: big output buffer %d", + c->self, buffer_len(&c->output)); return 0; + } } } return 1; } -/* This is called after receiving CHANNEL_CLOSE/IEOF. */ +void +channel_input_ieof(int type, int plen) +{ + int id; + Channel *c; + + packet_integrity_check(plen, 4, type); + + id = packet_get_int(); + c = channel_lookup(id); + if (c == NULL) + packet_disconnect("Received ieof for nonexistent channel %d.", id); + chan_rcvd_ieof(c); +} void -channel_input_close() +channel_input_close(int type, int plen) { - int channel; + int id; + Channel *c; - /* Get the channel number and verify it. */ - channel = packet_get_int(); - if (channel < 0 || channel >= channels_alloc || - channels[channel].type == SSH_CHANNEL_FREE) - packet_disconnect("Received data for nonexistent channel %d.", channel); - - if (!compat13) { - /* proto version 1.5 overloads CLOSE with IEOF */ - chan_rcvd_ieof(&channels[channel]); - return; - } + packet_integrity_check(plen, 4, type); + + id = packet_get_int(); + c = channel_lookup(id); + if (c == NULL) + packet_disconnect("Received close for nonexistent channel %d.", id); /* * Send a confirmation that we have closed the channel and no more * data is coming for it. */ packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION); - packet_put_int(channels[channel].remote_id); + packet_put_int(c->remote_id); packet_send(); /* @@ -672,81 +843,80 @@ channel_input_close() * no-one to receive the confirmation. The channel gets freed when * the confirmation arrives. */ - if (channels[channel].type != SSH_CHANNEL_CLOSED) { + if (c->type != SSH_CHANNEL_CLOSED) { /* * Not a closed channel - mark it as draining, which will * cause it to be freed later. */ - buffer_consume(&channels[channel].input, - buffer_len(&channels[channel].input)); - channels[channel].type = SSH_CHANNEL_OUTPUT_DRAINING; + buffer_consume(&c->input, buffer_len(&c->input)); + c->type = SSH_CHANNEL_OUTPUT_DRAINING; } } -/* This is called after receiving CHANNEL_CLOSE_CONFIRMATION/OCLOSE. */ - +/* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */ void -channel_input_close_confirmation() +channel_input_oclose(int type, int plen) { - int channel; - - /* Get the channel number and verify it. */ - channel = packet_get_int(); - if (channel < 0 || channel >= channels_alloc) - packet_disconnect("Received close confirmation for out-of-range channel %d.", - channel); - - if (!compat13) { - /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */ - chan_rcvd_oclose(&channels[channel]); - return; - } - if (channels[channel].type != SSH_CHANNEL_CLOSED) - packet_disconnect("Received close confirmation for non-closed channel %d (type %d).", - channel, channels[channel].type); - - /* Free the channel. */ - channel_free(channel); + int id = packet_get_int(); + Channel *c = channel_lookup(id); + packet_integrity_check(plen, 4, type); + if (c == NULL) + packet_disconnect("Received oclose for nonexistent channel %d.", id); + chan_rcvd_oclose(c); } -/* This is called after receiving CHANNEL_OPEN_CONFIRMATION. */ +void +channel_input_close_confirmation(int type, int plen) +{ + int id = packet_get_int(); + Channel *c = channel_lookup(id); + + if (c == NULL) + packet_disconnect("Received close confirmation for " + "out-of-range channel %d.", id); + if (c->type != SSH_CHANNEL_CLOSED) + packet_disconnect("Received close confirmation for " + "non-closed channel %d (type %d).", id, c->type); + channel_free(c->self); +} void -channel_input_open_confirmation() +channel_input_open_confirmation(int type, int plen) { - int channel, remote_channel; + int id, remote_id; + Channel *c; - /* Get the channel number and verify it. */ - channel = packet_get_int(); - if (channel < 0 || channel >= channels_alloc || - channels[channel].type != SSH_CHANNEL_OPENING) - packet_disconnect("Received open confirmation for non-opening channel %d.", - channel); + packet_integrity_check(plen, 4 + 4, type); - /* Get remote side's id for this channel. */ - remote_channel = packet_get_int(); + id = packet_get_int(); + c = channel_lookup(id); + if (c==NULL || c->type != SSH_CHANNEL_OPENING) + packet_disconnect("Received open confirmation for " + "non-opening channel %d.", id); + remote_id = packet_get_int(); /* Record the remote channel number and mark that the channel is now open. */ - channels[channel].remote_id = remote_channel; - channels[channel].type = SSH_CHANNEL_OPEN; + c->remote_id = remote_id; + c->type = SSH_CHANNEL_OPEN; } -/* This is called after receiving CHANNEL_OPEN_FAILURE from the other side. */ - void -channel_input_open_failure() +channel_input_open_failure(int type, int plen) { - int channel; + int id; + Channel *c; - /* Get the channel number and verify it. */ - channel = packet_get_int(); - if (channel < 0 || channel >= channels_alloc || - channels[channel].type != SSH_CHANNEL_OPENING) - packet_disconnect("Received open failure for non-opening channel %d.", - channel); + packet_integrity_check(plen, 4, type); + + id = packet_get_int(); + c = channel_lookup(id); + + if (c==NULL || c->type != SSH_CHANNEL_OPENING) + packet_disconnect("Received open failure for " + "non-opening channel %d.", id); /* Free the channel. This will also close the socket. */ - channel_free(channel); + channel_free(id); } /* @@ -859,15 +1029,16 @@ channel_open_message() case SSH_CHANNEL_X11_OPEN: case SSH_CHANNEL_INPUT_DRAINING: case SSH_CHANNEL_OUTPUT_DRAINING: - snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d)\r\n", + snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n", c->self, c->remote_name, c->type, c->remote_id, c->istate, buffer_len(&c->input), - c->ostate, buffer_len(&c->output)); + c->ostate, buffer_len(&c->output), + c->rfd, c->wfd); buffer_append(&buffer, buf, strlen(buf)); continue; default: - fatal("channel_still_open: bad channel type %d", c->type); + fatal("channel_open_message: bad channel type %d", c->type); /* NOTREACHED */ } } @@ -950,8 +1121,11 @@ channel_request_local_forwarding(u_short port, const char *host, continue; } /* Allocate a channel number for the socket. */ - ch = channel_allocate(SSH_CHANNEL_PORT_LISTENER, sock, - xstrdup("port listener")); + ch = channel_new( + "port listener", SSH_CHANNEL_PORT_LISTENER, + sock, sock, -1, + CHAN_WINDOW_DEFAULT, CHAN_PACKET_DEFAULT, + 0, xstrdup("port listener")); strlcpy(channels[ch].path, host, sizeof(channels[ch].path)); channels[ch].host_port = host_port; channels[ch].listening_port = port; @@ -968,26 +1142,26 @@ channel_request_local_forwarding(u_short port, const char *host, */ void -channel_request_remote_forwarding(u_short port, const char *host, - u_short remote_port) +channel_request_remote_forwarding(u_short listen_port, const char *host_to_connect, + u_short port_to_connect) { int payload_len; /* Record locally that connection to this host/port is permitted. */ if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION) fatal("channel_request_remote_forwarding: too many forwards"); - permitted_opens[num_permitted_opens].host = xstrdup(host); - permitted_opens[num_permitted_opens].port = remote_port; + permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect); + permitted_opens[num_permitted_opens].port_to_connect = port_to_connect; + permitted_opens[num_permitted_opens].listen_port = listen_port; num_permitted_opens++; /* Send the forward request to the remote side. */ packet_start(SSH_CMSG_PORT_FORWARD_REQUEST); - packet_put_int(port); - packet_put_string(host, strlen(host)); - packet_put_int(remote_port); + packet_put_int(port_to_connect); + packet_put_string(host_to_connect, strlen(host_to_connect)); + packet_put_int(listen_port); packet_send(); packet_write_wait(); - /* * Wait for response from the remote side. It will send a disconnect * message on failure, and we will never see it here. @@ -1029,63 +1203,14 @@ channel_input_port_forward_request(int is_root) xfree(hostname); } -/* - * This is called after receiving PORT_OPEN message. This attempts to - * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION - * or CHANNEL_OPEN_FAILURE. - */ - -void -channel_input_port_open(int payload_len) +/* XXX move to aux.c */ +int +channel_connect_to(const char *host, u_short host_port) { - int remote_channel, sock = 0, newch, i; - u_short host_port; - char *host, *originator_string; - unsigned int host_len, originator_len; struct addrinfo hints, *ai, *aitop; char ntop[NI_MAXHOST], strport[NI_MAXSERV]; int gaierr; - - /* Get remote channel number. */ - remote_channel = packet_get_int(); - - /* Get host name to connect to. */ - host = packet_get_string(&host_len); - - /* Get port to connect to. */ - host_port = packet_get_int(); - - /* Get remote originator name. */ - if (have_hostname_in_open) { - originator_string = packet_get_string(&originator_len); - originator_len += 4; /* size of packet_int */ - } else { - originator_string = xstrdup("unknown (remote did not supply name)"); - originator_len = 0; /* no originator supplied */ - } - - packet_integrity_check(payload_len, - 4 + 4 + host_len + 4 + originator_len, - SSH_MSG_PORT_OPEN); - - /* Check if opening that port is permitted. */ - if (!all_opens_permitted) { - /* Go trough all permitted ports. */ - for (i = 0; i < num_permitted_opens; i++) - if (permitted_opens[i].port == host_port && - strcmp(permitted_opens[i].host, host) == 0) - break; - - /* Check if we found the requested port among those permitted. */ - if (i >= num_permitted_opens) { - /* The port is not permitted. */ - log("Received request to connect to %.100s:%d, but the request was denied.", - host, host_port); - packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); - packet_put_int(remote_channel); - packet_send(); - } - } + int sock = -1; memset(&hints, 0, sizeof(hints)); hints.ai_family = IPv4or6; @@ -1093,15 +1218,14 @@ channel_input_port_open(int payload_len) snprintf(strport, sizeof strport, "%d", host_port); if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) { error("%.100s: unknown host (%s)", host, gai_strerror(gaierr)); - goto fail; + return -1; } - for (ai = aitop; ai; ai = ai->ai_next) { if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) continue; if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { - error("channel_input_port_open: getnameinfo failed"); + error("channel_connect_to: getnameinfo failed"); continue; } /* Create the socket. */ @@ -1121,37 +1245,82 @@ channel_input_port_open(int payload_len) } freeaddrinfo(aitop); - if (!ai) { error("connect %.100s port %d: failed.", host, host_port); - goto fail; + return -1; } + /* success */ + return sock; +} - /* Successful connection. */ +/* + * This is called after receiving PORT_OPEN message. This attempts to + * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION + * or CHANNEL_OPEN_FAILURE. + */ - /* Allocate a channel for this connection. */ - newch = channel_allocate(SSH_CHANNEL_OPEN, sock, originator_string); - channels[newch].remote_id = remote_channel; +void +channel_input_port_open(int type, int plen) +{ + u_short host_port; + char *host, *originator_string; + int remote_channel, sock = -1, newch, i, denied; + unsigned int host_len, originator_len; - /* Send a confirmation to the remote host. */ - packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); - packet_put_int(remote_channel); - packet_put_int(newch); - packet_send(); + /* Get remote channel number. */ + remote_channel = packet_get_int(); - /* Free the argument string. */ - xfree(host); + /* Get host name to connect to. */ + host = packet_get_string(&host_len); - return; + /* Get port to connect to. */ + host_port = packet_get_int(); -fail: - /* Free the argument string. */ - xfree(host); + /* Get remote originator name. */ + if (have_hostname_in_open) { + originator_string = packet_get_string(&originator_len); + originator_len += 4; /* size of packet_int */ + } else { + originator_string = xstrdup("unknown (remote did not supply name)"); + originator_len = 0; /* no originator supplied */ + } - /* Send refusal to the remote host. */ - packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); - packet_put_int(remote_channel); - packet_send(); + packet_integrity_check(plen, + 4 + 4 + host_len + 4 + originator_len, SSH_MSG_PORT_OPEN); + + /* Check if opening that port is permitted. */ + denied = 0; + if (!all_opens_permitted) { + /* Go trough all permitted ports. */ + for (i = 0; i < num_permitted_opens; i++) + if (permitted_opens[i].port_to_connect == host_port && + strcmp(permitted_opens[i].host_to_connect, host) == 0) + break; + + /* Check if we found the requested port among those permitted. */ + if (i >= num_permitted_opens) { + /* The port is not permitted. */ + log("Received request to connect to %.100s:%d, but the request was denied.", + host, host_port); + denied = 1; + } + } + sock = denied ? -1 : channel_connect_to(host, host_port); + if (sock > 0) { + /* Allocate a channel for this connection. */ + newch = channel_allocate(SSH_CHANNEL_OPEN, sock, originator_string); + channels[newch].remote_id = remote_channel; + + packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); + packet_put_int(remote_channel); + packet_put_int(newch); + packet_send(); + } else { + packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); + packet_put_int(remote_channel); + packet_send(); + } + xfree(host); } /* @@ -1336,7 +1505,7 @@ connect_local_xsocket(unsigned int dnr) */ void -x11_input_open(int payload_len) +x11_input_open(int type, int plen) { int remote_channel, display_number, sock = 0, newch; const char *display; @@ -1359,7 +1528,7 @@ x11_input_open(int payload_len) } debug("Received X11 open request."); - packet_integrity_check(payload_len, 4 + remote_len, SSH_SMSG_X11_OPEN); + packet_integrity_check(plen, 4 + remote_len, SSH_SMSG_X11_OPEN); /* Try to open a socket for the local X server. */ display = getenv("DISPLAY"); @@ -1425,19 +1594,18 @@ x11_input_open(int payload_len) sock = socket(ai->ai_family, SOCK_STREAM, 0); if (sock < 0) { debug("socket: %.100s", strerror(errno)); - continue; - } - /* Connect it to the display. */ - if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) { - debug("connect %.100s port %d: %.100s", buf, 6000 + display_number, - strerror(errno)); - close(sock); - continue; + continue; + } + /* Connect it to the display. */ + if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) { + debug("connect %.100s port %d: %.100s", buf, + 6000 + display_number, strerror(errno)); + close(sock); + continue; + } + /* Success */ + break; } - /* Success */ - break; - - } /* (ai = aitop, ai; ai = ai->ai_next) */ freeaddrinfo(aitop); if (!ai) { error("connect %.100s port %d: %.100s", buf, 6000 + display_number, @@ -1625,11 +1793,13 @@ auth_input_request_forwarding(struct passwd * pw) /* This is called to process an SSH_SMSG_AGENT_OPEN message. */ void -auth_input_open_request() +auth_input_open_request(int type, int plen) { int remch, sock, newch; char *dummyname; + packet_integrity_check(plen, 4, type); + /* Read the remote channel number from the message. */ remch = packet_get_int(); diff --git a/channels.h b/channels.h index f8bca5c9a..73ff5a595 100644 --- a/channels.h +++ b/channels.h @@ -1,4 +1,4 @@ -/* RCSID("$Id: channels.h,v 1.4 1999/11/25 00:54:58 damien Exp $"); */ +/* RCSID("$Id: channels.h,v 1.5 2000/04/01 01:09:23 damien Exp $"); */ #ifndef CHANNELS_H #define CHANNELS_H @@ -10,17 +10,18 @@ #define SSH_CHANNEL_OPENING 3 /* waiting for confirmation */ #define SSH_CHANNEL_OPEN 4 /* normal open two-way channel */ #define SSH_CHANNEL_CLOSED 5 /* waiting for close confirmation */ -/* SSH_CHANNEL_AUTH_FD 6 authentication fd */ -#define SSH_CHANNEL_AUTH_SOCKET 7 /* authentication socket */ -/* SSH_CHANNEL_AUTH_SOCKET_FD 8 connection to auth socket */ -#define SSH_CHANNEL_X11_OPEN 9 /* reading first X11 packet */ -#define SSH_CHANNEL_INPUT_DRAINING 10 /* sending remaining data to conn */ -#define SSH_CHANNEL_OUTPUT_DRAINING 11 /* sending remaining data to app */ +#define SSH_CHANNEL_AUTH_SOCKET 6 /* authentication socket */ +#define SSH_CHANNEL_X11_OPEN 7 /* reading first X11 packet */ +#define SSH_CHANNEL_INPUT_DRAINING 8 /* sending remaining data to conn */ +#define SSH_CHANNEL_OUTPUT_DRAINING 9 /* sending remaining data to app */ +#define SSH_CHANNEL_LARVAL 10 /* larval session */ +#define SSH_CHANNEL_MAX_TYPE 11 /* * Data structure for channel data. This is iniailized in channel_allocate * and cleared in channel_free. */ +typedef void channel_callback_fn(int id, void *arg); typedef struct Channel { int type; /* channel type/state */ @@ -29,15 +30,192 @@ typedef struct Channel { /* peer can be reached over encrypted connection, via packet-sent */ int istate; /* input from channel (state of receive half) */ int ostate; /* output to channel (state of transmit half) */ - int sock; /* data socket, linked to this channel */ + int rfd; /* read fd */ + int wfd; /* write fd */ + int efd; /* extended fd */ + int sock; /* sock fd */ Buffer input; /* data read from socket, to be sent over * encrypted connection */ Buffer output; /* data received over encrypted connection for * send on socket */ + Buffer extended; char path[200]; /* path for unix domain sockets, or host name * for forwards */ int listening_port; /* port being listened for forwards */ int host_port; /* remote port to connect for forwards */ char *remote_name; /* remote hostname */ + + int remote_window; + int remote_maxpacket; + int local_window; + int local_window_max; + int local_consumed; + int local_maxpacket; + int extended_usage; + + char *ctype; /* type */ + + // callback + channel_callback_fn *cb_fn; + void *cb_arg; + int cb_event; + channel_callback_fn *dettach_user; } Channel; + +#define CHAN_EXTENDED_IGNORE 0 +#define CHAN_EXTENDED_READ 1 +#define CHAN_EXTENDED_WRITE 2 + +void channel_open(int id); +Channel *channel_lookup(int id); + +int +channel_new(char *ctype, int type, int rfd, int wfd, int efd, + int window, int maxpack, int extended_usage, char *remote_name); + +void channel_input_close(int type, int plen); +void channel_input_close_confirmation(int type, int plen); +void channel_input_data(int type, int plen); +void channel_input_ieof(int type, int plen); +void channel_input_oclose(int type, int plen); +void channel_input_open_confirmation(int type, int plen); +void channel_input_open_failure(int type, int plen); +void channel_input_port_open(int type, int plen); +void channel_input_open(int type, int plen); + +/* Sets specific protocol options. */ +void channel_set_options(int hostname_in_open); + +/* + * Allocate a new channel object and set its type and socket. Remote_name + * must have been allocated with xmalloc; this will free it when the channel + * is freed. + */ +int channel_allocate(int type, int sock, char *remote_name); + +/* Free the channel and close its socket. */ +void channel_free(int channel); + +/* Add any bits relevant to channels in select bitmasks. */ +void channel_prepare_select(fd_set * readset, fd_set * writeset); + +/* + * After select, perform any appropriate operations for channels which have + * events pending. + */ +void channel_after_select(fd_set * readset, fd_set * writeset); + +/* If there is data to send to the connection, send some of it now. */ +void channel_output_poll(void); + +/* Returns true if no channel has too much buffered data. */ +int channel_not_very_much_buffered_data(void); + +/* This closes any sockets that are listening for connections; this removes + any unix domain sockets. */ +void channel_stop_listening(void); + +/* + * Closes the sockets of all channels. This is used to close extra file + * descriptors after a fork. + */ +void channel_close_all(void); + +/* Returns the maximum file descriptor number used by the channels. */ +int channel_max_fd(void); + +/* Returns true if there is still an open channel over the connection. */ +int channel_still_open(void); + +/* + * Returns a string containing a list of all open channels. The list is + * suitable for displaying to the user. It uses crlf instead of newlines. + * The caller should free the string with xfree. + */ +char *channel_open_message(void); + +/* + * Initiate forwarding of connections to local port "port" through the secure + * channel to host:port from remote side. This never returns if there was an + * error. + */ +void +channel_request_local_forwarding(u_short port, const char *host, + u_short remote_port, int gateway_ports); + +/* + * Initiate forwarding of connections to port "port" on remote host through + * the secure channel to host:port from local side. This never returns if + * there was an error. This registers that open requests for that port are + * permitted. + */ +void +channel_request_remote_forwarding(u_short port, const char *host, + u_short remote_port); + +/* + * Permits opening to any host/port in SSH_MSG_PORT_OPEN. This is usually + * called by the server, because the user could connect to any port anyway, + * and the server has no way to know but to trust the client anyway. + */ +void channel_permit_all_opens(void); + +/* + * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates + * listening for the port, and sends back a success reply (or disconnect + * message if there was an error). This never returns if there was an error. + */ +void channel_input_port_forward_request(int is_root); + +/* + * Creates a port for X11 connections, and starts listening for it. Returns + * the display name, or NULL if an error was encountered. + */ +char *x11_create_display(int screen); + +/* + * Creates an internet domain socket for listening for X11 connections. + * Returns a suitable value for the DISPLAY variable, or NULL if an error + * occurs. + */ +char *x11_create_display_inet(int screen, int x11_display_offset); + +/* + * This is called when SSH_SMSG_X11_OPEN is received. The packet contains + * the remote channel number. We should do whatever we want, and respond + * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE. + */ +void x11_input_open(int type, int plen); + +/* + * Requests forwarding of X11 connections. This should be called on the + * client only. + */ +void x11_request_forwarding(void); + +/* + * Requests forwarding for X11 connections, with authentication spoofing. + * This should be called in the client only. + */ +void x11_request_forwarding_with_spoofing(const char *proto, const char *data); + +/* Sends a message to the server to request authentication fd forwarding. */ +void auth_request_forwarding(void); + +/* + * Returns the name of the forwarded authentication socket. Returns NULL if + * there is no forwarded authentication socket. The returned value points to + * a static buffer. + */ +char *auth_get_socket_name(void); + +/* + * This if called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server. + * This starts forwarding authentication requests. + */ +void auth_input_request_forwarding(struct passwd * pw); + +/* This is called to process an SSH_SMSG_AGENT_OPEN message. */ +void auth_input_open_request(int type, int plen); + #endif @@ -12,7 +12,7 @@ */ #include "includes.h" -RCSID("$Id: cipher.c,v 1.14 2000/03/26 03:04:52 damien Exp $"); +RCSID("$Id: cipher.c,v 1.15 2000/04/01 01:09:23 damien Exp $"); #include "ssh.h" #include "cipher.h" @@ -122,7 +122,12 @@ static char *cipher_names[] = "3des", "tss", "rc4", - "blowfish" + "blowfish", + "reserved", + "blowfish-cbc", + "3des-cbc", + "arcfour", + "cast128-cbc" }; /* @@ -137,6 +142,10 @@ cipher_mask() unsigned int mask = 0; mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */ mask |= 1 << SSH_CIPHER_BLOWFISH; + mask |= 1 << SSH_CIPHER_BLOWFISH_CBC; + mask |= 1 << SSH_CIPHER_3DES_CBC; + mask |= 1 << SSH_CIPHER_ARCFOUR; + mask |= 1 << SSH_CIPHER_CAST128_CBC; return mask; } @@ -233,16 +242,84 @@ cipher_set_key(CipherContext *context, int cipher, break; case SSH_CIPHER_BLOWFISH: + if (keylen < 16) + error("Key length %d is insufficient for blowfish.", keylen); BF_set_key(&context->u.bf.key, keylen, padded); memset(context->u.bf.iv, 0, 8); break; + case SSH_CIPHER_3DES_CBC: + case SSH_CIPHER_BLOWFISH_CBC: + case SSH_CIPHER_ARCFOUR: + case SSH_CIPHER_CAST128_CBC: + fatal("cipher_set_key: illegal cipher: %s", cipher_name(cipher)); + break; + default: fatal("cipher_set_key: unknown cipher: %s", cipher_name(cipher)); } memset(padded, 0, sizeof(padded)); } + +void +cipher_set_key_iv(CipherContext * context, int cipher, + const unsigned char *key, int keylen, + const unsigned char *iv, int ivlen) +{ + /* Set cipher type. */ + context->type = cipher; + + /* Initialize the initialization vector. */ + switch (cipher) { + case SSH_CIPHER_NONE: + break; + + case SSH_CIPHER_3DES: + case SSH_CIPHER_BLOWFISH: + fatal("cipher_set_key_iv: illegal cipher: %s", cipher_name(cipher)); + break; + + case SSH_CIPHER_3DES_CBC: + if (keylen < 24) + error("Key length %d is insufficient for 3des-cbc.", keylen); + des_set_key((void *) key, context->u.des3.key1); + des_set_key((void *) (key+8), context->u.des3.key2); + des_set_key((void *) (key+16), context->u.des3.key3); + if (ivlen < 8) + error("IV length %d is insufficient for 3des-cbc.", ivlen); + memcpy(context->u.des3.iv3, (char *)iv, 8); + break; + + case SSH_CIPHER_BLOWFISH_CBC: + if (keylen < 16) + error("Key length %d is insufficient for blowfish.", keylen); + if (ivlen < 8) + error("IV length %d is insufficient for blowfish.", ivlen); + BF_set_key(&context->u.bf.key, keylen, (unsigned char *)key); + memcpy(context->u.bf.iv, (char *)iv, 8); + break; + + case SSH_CIPHER_ARCFOUR: + if (keylen < 16) + error("Key length %d is insufficient for arcfour.", keylen); + RC4_set_key(&context->u.rc4, keylen, (unsigned char *)key); + break; + + case SSH_CIPHER_CAST128_CBC: + if (keylen < 16) + error("Key length %d is insufficient for cast128.", keylen); + if (ivlen < 8) + error("IV length %d is insufficient for cast128.", ivlen); + CAST_set_key(&context->u.cast.key, keylen, (unsigned char *) key); + memcpy(context->u.cast.iv, (char *)iv, 8); + break; + + default: + fatal("cipher_set_key: unknown cipher: %s", cipher_name(cipher)); + } +} + /* Encrypts data using the cipher. */ void @@ -272,6 +349,27 @@ cipher_encrypt(CipherContext *context, unsigned char *dest, swap_bytes(dest, dest, len); break; + case SSH_CIPHER_BLOWFISH_CBC: + BF_cbc_encrypt((void *)src, dest, len, + &context->u.bf.key, context->u.bf.iv, + BF_ENCRYPT); + break; + + case SSH_CIPHER_3DES_CBC: + des_ede3_cbc_encrypt(src, dest, len, + context->u.des3.key1, context->u.des3.key2, + context->u.des3.key3, &context->u.des3.iv3, DES_ENCRYPT); + break; + + case SSH_CIPHER_ARCFOUR: + RC4(&context->u.rc4, len, (unsigned char *)src, dest); + break; + + case SSH_CIPHER_CAST128_CBC: + CAST_cbc_encrypt(src, dest, len, + &context->u.cast.key, context->u.cast.iv, CAST_ENCRYPT); + break; + default: fatal("cipher_encrypt: unknown cipher: %s", cipher_name(context->type)); } @@ -306,6 +404,27 @@ cipher_decrypt(CipherContext *context, unsigned char *dest, swap_bytes(dest, dest, len); break; + case SSH_CIPHER_BLOWFISH_CBC: + BF_cbc_encrypt((void *) src, dest, len, + &context->u.bf.key, context->u.bf.iv, + BF_DECRYPT); + break; + + case SSH_CIPHER_3DES_CBC: + des_ede3_cbc_encrypt(src, dest, len, + context->u.des3.key1, context->u.des3.key2, + context->u.des3.key3, &context->u.des3.iv3, DES_DECRYPT); + break; + + case SSH_CIPHER_ARCFOUR: + RC4(&context->u.rc4, len, (unsigned char *)src, dest); + break; + + case SSH_CIPHER_CAST128_CBC: + CAST_cbc_encrypt(src, dest, len, + &context->u.cast.key, context->u.cast.iv, CAST_DECRYPT); + break; + default: fatal("cipher_decrypt: unknown cipher: %s", cipher_name(context->type)); } @@ -11,7 +11,7 @@ * */ -/* RCSID("$Id: cipher.h,v 1.6 2000/03/26 03:04:52 damien Exp $"); */ +/* RCSID("$Id: cipher.h,v 1.7 2000/04/01 01:09:23 damien Exp $"); */ #ifndef CIPHER_H #define CIPHER_H @@ -21,10 +21,14 @@ #ifdef HAVE_OPENSSL #include <openssl/des.h> #include <openssl/blowfish.h> +#include <openssl/rc4.h> +#include <openssl/cast.h> #endif #ifdef HAVE_SSL #include <ssl/des.h> #include <ssl/blowfish.h> +#include <ssl/rc4.h> +#include <ssl/cast.h> #endif /* Cipher types. New types can be added, but old types should not be removed @@ -37,6 +41,13 @@ #define SSH_CIPHER_BROKEN_TSS 4 /* TRI's Simple Stream encryption CBC */ #define SSH_CIPHER_BROKEN_RC4 5 /* Alleged RC4 */ #define SSH_CIPHER_BLOWFISH 6 +#define SSH_CIPHER_RESERVED 7 + +/* these ciphers are used in SSH2: */ +#define SSH_CIPHER_BLOWFISH_CBC 8 +#define SSH_CIPHER_3DES_CBC 9 +#define SSH_CIPHER_ARCFOUR 10 /* Alleged RC4 */ +#define SSH_CIPHER_CAST128_CBC 11 typedef struct { unsigned int type; @@ -52,6 +63,11 @@ typedef struct { struct bf_key_st key; unsigned char iv[8]; } bf; + struct { + CAST_KEY key; + unsigned char iv[8]; + } cast; + RC4_KEY rc4; } u; } CipherContext; /* @@ -77,6 +93,10 @@ int cipher_number(const char *name); void cipher_set_key(CipherContext * context, int cipher, const unsigned char *key, int keylen, int for_encryption); +void +cipher_set_key_iv(CipherContext * context, int cipher, + const unsigned char *key, int keylen, + const unsigned char *iv, int ivlen); /* * Sets key for the cipher by computing the MD5 checksum of the passphrase, diff --git a/clientloop.c b/clientloop.c index bfa3019b6..1bc6d7e67 100644 --- a/clientloop.c +++ b/clientloop.c @@ -15,7 +15,7 @@ */ #include "includes.h" -RCSID("$Id: clientloop.c,v 1.7 1999/12/07 04:38:32 damien Exp $"); +RCSID("$Id: clientloop.c,v 1.8 2000/04/01 01:09:23 damien Exp $"); #include "xmalloc.h" #include "ssh.h" @@ -24,6 +24,11 @@ RCSID("$Id: clientloop.c,v 1.7 1999/12/07 04:38:32 damien Exp $"); #include "authfd.h" #include "readconf.h" +#include "compat.h" +#include "channels.h" +#include "dispatch.h" + + /* Flag indicating that stdin should be redirected from /dev/null. */ extern int stdin_null_flag; @@ -228,108 +233,6 @@ client_check_initial_eof_on_stdin() } } -/* - * Get packets from the connection input buffer, and process them as long as - * there are packets available. - */ - -void -client_process_buffered_input_packets() -{ - int type; - char *data; - unsigned int data_len; - int payload_len; - - /* Process any buffered packets from the server. */ - while (!quit_pending && - (type = packet_read_poll(&payload_len)) != SSH_MSG_NONE) { - switch (type) { - - case SSH_SMSG_STDOUT_DATA: - data = packet_get_string(&data_len); - packet_integrity_check(payload_len, 4 + data_len, type); - buffer_append(&stdout_buffer, data, data_len); - stdout_bytes += data_len; - memset(data, 0, data_len); - xfree(data); - break; - - case SSH_SMSG_STDERR_DATA: - data = packet_get_string(&data_len); - packet_integrity_check(payload_len, 4 + data_len, type); - buffer_append(&stderr_buffer, data, data_len); - stdout_bytes += data_len; - memset(data, 0, data_len); - xfree(data); - break; - - case SSH_SMSG_EXITSTATUS: - packet_integrity_check(payload_len, 4, type); - exit_status = packet_get_int(); - /* Acknowledge the exit. */ - packet_start(SSH_CMSG_EXIT_CONFIRMATION); - packet_send(); - /* - * Must wait for packet to be sent since we are - * exiting the loop. - */ - packet_write_wait(); - /* Flag that we want to exit. */ - quit_pending = 1; - break; - - case SSH_SMSG_X11_OPEN: - x11_input_open(payload_len); - break; - - case SSH_MSG_PORT_OPEN: - channel_input_port_open(payload_len); - break; - - case SSH_SMSG_AGENT_OPEN: - packet_integrity_check(payload_len, 4, type); - auth_input_open_request(); - break; - - case SSH_MSG_CHANNEL_OPEN_CONFIRMATION: - packet_integrity_check(payload_len, 4 + 4, type); - channel_input_open_confirmation(); - break; - - case SSH_MSG_CHANNEL_OPEN_FAILURE: - packet_integrity_check(payload_len, 4, type); - channel_input_open_failure(); - break; - - case SSH_MSG_CHANNEL_DATA: - channel_input_data(payload_len); - break; - - case SSH_MSG_CHANNEL_CLOSE: - packet_integrity_check(payload_len, 4, type); - channel_input_close(); - break; - - case SSH_MSG_CHANNEL_CLOSE_CONFIRMATION: - packet_integrity_check(payload_len, 4, type); - channel_input_close_confirmation(); - break; - - default: - /* - * Any unknown packets received during the actual - * session cause the session to terminate. This is - * intended to make debugging easier since no - * confirmations are sent. Any compatible protocol - * extensions must be negotiated during the - * preparatory phase. - */ - packet_disconnect("Protocol error during session: type %d", - type); - } - } -} /* * Make packets from buffered stdin data, and buffer them for sending to the @@ -776,12 +679,32 @@ client_process_output(fd_set * writeset) } /* + * Get packets from the connection input buffer, and process them as long as + * there are packets available. + * + * Any unknown packets received during the actual + * session cause the session to terminate. This is + * intended to make debugging easier since no + * confirmations are sent. Any compatible protocol + * extensions must be negotiated during the + * preparatory phase. + */ + +void +client_process_buffered_input_packets() +{ + dispatch_run(DISPATCH_NONBLOCK, &quit_pending); +} + +/* * Implements the interactive session with the server. This is called after * the user has been authenticated, and a command has been started on the * remote host. If escape_char != -1, it is the character used as an escape * character for terminating or suspending the session. */ +void client_init_dispatch(void); + int client_loop(int have_pty, int escape_char_arg) { @@ -816,6 +739,8 @@ client_loop(int have_pty, int escape_char_arg) buffer_init(&stdout_buffer); buffer_init(&stderr_buffer); + client_init_dispatch(); + /* Set signal handlers to restore non-blocking mode. */ signal(SIGINT, signal_handler); signal(SIGQUIT, signal_handler); @@ -950,3 +875,77 @@ client_loop(int have_pty, int escape_char_arg) debug("Exit status %d", exit_status); return exit_status; } + +/*********/ + +void +client_input_stdout_data(int type, int plen) +{ + unsigned int data_len; + char *data = packet_get_string(&data_len); + packet_integrity_check(plen, 4 + data_len, type); + buffer_append(&stdout_buffer, data, data_len); + stdout_bytes += data_len; + memset(data, 0, data_len); + xfree(data); +} +void +client_input_stderr_data(int type, int plen) +{ + unsigned int data_len; + char *data = packet_get_string(&data_len); + packet_integrity_check(plen, 4 + data_len, type); + buffer_append(&stderr_buffer, data, data_len); + stdout_bytes += data_len; + memset(data, 0, data_len); + xfree(data); +} +void +client_input_exit_status(int type, int plen) +{ + packet_integrity_check(plen, 4, type); + exit_status = packet_get_int(); + /* Acknowledge the exit. */ + packet_start(SSH_CMSG_EXIT_CONFIRMATION); + packet_send(); + /* + * Must wait for packet to be sent since we are + * exiting the loop. + */ + packet_write_wait(); + /* Flag that we want to exit. */ + quit_pending = 1; +} + +void +client_init_dispatch_13() +{ + dispatch_init(NULL); + dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); + dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); + dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); + dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); + dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); + dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); + dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); + dispatch_set(SSH_SMSG_AGENT_OPEN, &auth_input_open_request); + dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status); + dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data); + dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data); + dispatch_set(SSH_SMSG_X11_OPEN, &x11_input_open); +} +void +client_init_dispatch_15() +{ + client_init_dispatch_13(); + dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); + dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose); +} +void +client_init_dispatch() +{ + if (compat13) + client_init_dispatch_13(); + else + client_init_dispatch_15(); +} diff --git a/compress.c b/compress.c index cf15c6670..ee5cdccb5 100644 --- a/compress.c +++ b/compress.c @@ -14,7 +14,7 @@ */ #include "includes.h" -RCSID("$Id: compress.c,v 1.4 2000/03/17 12:40:16 damien Exp $"); +RCSID("$Id: compress.c,v 1.5 2000/04/01 01:09:24 damien Exp $"); #include "ssh.h" #include "buffer.h" @@ -90,23 +90,13 @@ buffer_compress(Buffer * input_buffer, Buffer * output_buffer) case Z_OK: /* Append compressed data to output_buffer. */ buffer_append(output_buffer, buf, - sizeof(buf) - outgoing_stream.avail_out); + sizeof(buf) - outgoing_stream.avail_out); break; - case Z_STREAM_END: - fatal("buffer_compress: deflate returned Z_STREAM_END"); - /* NOTREACHED */ - case Z_STREAM_ERROR: - fatal("buffer_compress: deflate returned Z_STREAM_ERROR"); - /* NOTREACHED */ - case Z_BUF_ERROR: - fatal("buffer_compress: deflate returned Z_BUF_ERROR"); - /* NOTREACHED */ default: fatal("buffer_compress: deflate returned %d", status); /* NOTREACHED */ } - } - while (outgoing_stream.avail_out == 0); + } while (outgoing_stream.avail_out == 0); } /* @@ -127,27 +117,17 @@ buffer_uncompress(Buffer * input_buffer, Buffer * output_buffer) incoming_stream.next_in = (unsigned char *) buffer_ptr(input_buffer); incoming_stream.avail_in = buffer_len(input_buffer); - incoming_stream.next_out = (unsigned char *) buf; - incoming_stream.avail_out = sizeof(buf); - for (;;) { + /* Set up fixed-size output buffer. */ + incoming_stream.next_out = (unsigned char *) buf; + incoming_stream.avail_out = sizeof(buf); + status = inflate(&incoming_stream, Z_PARTIAL_FLUSH); switch (status) { case Z_OK: buffer_append(output_buffer, buf, - sizeof(buf) - incoming_stream.avail_out); - incoming_stream.next_out = (unsigned char *) buf; - incoming_stream.avail_out = sizeof(buf); + sizeof(buf) - incoming_stream.avail_out); break; - case Z_STREAM_END: - fatal("buffer_uncompress: inflate returned Z_STREAM_END"); - /* NOTREACHED */ - case Z_DATA_ERROR: - fatal("buffer_uncompress: inflate returned Z_DATA_ERROR"); - /* NOTREACHED */ - case Z_STREAM_ERROR: - fatal("buffer_uncompress: inflate returned Z_STREAM_ERROR"); - /* NOTREACHED */ case Z_BUF_ERROR: /* * Comments in zlib.h say that we should keep calling @@ -155,11 +135,9 @@ buffer_uncompress(Buffer * input_buffer, Buffer * output_buffer) * be the error that we get. */ return; - case Z_MEM_ERROR: - fatal("buffer_uncompress: inflate returned Z_MEM_ERROR"); - /* NOTREACHED */ default: fatal("buffer_uncompress: inflate returned %d", status); + /* NOTREACHED */ } } } diff --git a/dispatch.c b/dispatch.c new file mode 100644 index 000000000..8594f986e --- /dev/null +++ b/dispatch.c @@ -0,0 +1,78 @@ +/* + * Copyright (c) 2000 Markus Friedl. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by Markus Friedl. + * 4. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ +#include "includes.h" +RCSID("$Id: dispatch.c,v 1.1 2000/04/01 01:09:24 damien Exp $"); +#include "ssh.h" +#include "dispatch.h" +#include "packet.h" + +#define DISPATCH_MIN 0 +#define DISPATCH_MAX 255 + +dispatch_fn *dispatch[DISPATCH_MAX]; + +void +dispatch_protocol_error(int type, int plen) +{ + error("Hm, dispatch protocol error: type %d plen %d", type, plen); +} +void +dispatch_init(dispatch_fn *dflt) +{ + int i; + for (i = 0; i < DISPATCH_MAX; i++) + dispatch[i] = dflt; +} +void +dispatch_set(int type, dispatch_fn *fn) +{ + dispatch[type] = fn; +} +void +dispatch_run(int mode, int *done) +{ + for (;;) { + int plen; + int type; + + if (mode == DISPATCH_BLOCK) { + type = packet_read(&plen); + } else { + type = packet_read_poll(&plen); + if (type == SSH_MSG_NONE) + return; + } + if (type > 0 && type < DISPATCH_MAX && dispatch[type] != NULL) + (*dispatch[type])(type, plen); + else + packet_disconnect("protocol error: rcvd type %d", type); + if (done != NULL && *done) + return; + } +} diff --git a/dispatch.h b/dispatch.h new file mode 100644 index 000000000..12084aafe --- /dev/null +++ b/dispatch.h @@ -0,0 +1,11 @@ +enum { + DISPATCH_BLOCK, + DISPATCH_NONBLOCK +}; + +typedef void dispatch_fn(int type, int plen); + +void dispatch_init(dispatch_fn *dflt); +void dispatch_set(int type, dispatch_fn *fn); +void dispatch_run(int mode, int *done); +void dispatch_protocol_error(int type, int plen); diff --git a/log-server.c b/log-server.c index 7f732ed3b..476e49f80 100644 --- a/log-server.c +++ b/log-server.c @@ -15,7 +15,7 @@ */ #include "includes.h" -RCSID("$Id: log-server.c,v 1.7 2000/03/09 10:27:50 damien Exp $"); +RCSID("$Id: log-server.c,v 1.8 2000/04/01 01:09:24 damien Exp $"); #include <syslog.h> #include "packet.h" @@ -137,9 +137,11 @@ do_log(LogLevel level, const char *fmt, va_list args) } else { vsnprintf(msgbuf, sizeof(msgbuf), fmt, args); } - if (log_on_stderr) + if (log_on_stderr) { fprintf(stderr, "%s\n", msgbuf); - openlog(__progname, LOG_PID, log_facility); - syslog(pri, "%.500s", msgbuf); - closelog(); + } else { + openlog(__progname, LOG_PID, log_facility); + syslog(pri, "%.500s", msgbuf); + closelog(); + } } @@ -15,7 +15,7 @@ */ #include "includes.h" -RCSID("$Id: mpaux.c,v 1.8 1999/12/13 23:47:16 damien Exp $"); +RCSID("$Id: mpaux.c,v 1.9 2000/04/01 01:09:24 damien Exp $"); #include "getput.h" #include "xmalloc.h" @@ -31,9 +31,9 @@ RCSID("$Id: mpaux.c,v 1.8 1999/12/13 23:47:16 damien Exp $"); void compute_session_id(unsigned char session_id[16], - unsigned char cookie[8], - BIGNUM* host_key_n, - BIGNUM* session_key_n) + unsigned char cookie[8], + BIGNUM* host_key_n, + BIGNUM* session_key_n) { unsigned int host_key_bytes = BN_num_bytes(host_key_n); unsigned int session_key_bytes = BN_num_bytes(session_key_n); @@ -28,7 +28,7 @@ */ #include "includes.h" -RCSID("$Id: nchan.c,v 1.5 2000/01/14 04:45:50 damien Exp $"); +RCSID("$Id: nchan.c,v 1.6 2000/04/01 01:09:24 damien Exp $"); #include "ssh.h" @@ -41,7 +41,6 @@ static void chan_send_ieof(Channel *c); static void chan_send_oclose(Channel *c); static void chan_shutdown_write(Channel *c); static void chan_shutdown_read(Channel *c); -static void chan_delete_if_full_closed(Channel *c); /* * EVENTS update channel input/output states execute ACTIONS @@ -73,7 +72,6 @@ chan_rcvd_oclose(Channel *c) error("protocol error: chan_rcvd_oclose %d for istate %d", c->self, c->istate); return; } - chan_delete_if_full_closed(c); } void chan_read_failed(Channel *c) @@ -121,7 +119,6 @@ chan_rcvd_ieof(Channel *c) case CHAN_OUTPUT_WAIT_IEOF: debug("channel %d: OUTPUT_WAIT_IEOF -> OUTPUT_CLOSED [rvcd IEOF]", c->self); c->ostate = CHAN_OUTPUT_CLOSED; - chan_delete_if_full_closed(c); break; default: error("protocol error: chan_rcvd_ieof %d for ostate %d", c->self, c->ostate); @@ -141,7 +138,6 @@ chan_write_failed(Channel *c) debug("channel %d: OUTPUT_WAIT_DRAIN -> OUTPUT_CLOSED [write failed]", c->self); chan_send_oclose(c); c->ostate = CHAN_OUTPUT_CLOSED; - chan_delete_if_full_closed(c); break; default: error("internal error: chan_write_failed %d for ostate %d", c->self, c->ostate); @@ -160,7 +156,6 @@ chan_obuf_empty(Channel *c) debug("channel %d: OUTPUT_WAIT_DRAIN -> OUTPUT_CLOSED [obuf empty, send OCLOSE]", c->self); chan_send_oclose(c); c->ostate = CHAN_OUTPUT_CLOSED; - chan_delete_if_full_closed(c); break; default: error("internal error: chan_obuf_empty %d for ostate %d", c->self, c->ostate); @@ -222,7 +217,7 @@ chan_shutdown_read(Channel *c) error("chan_shutdown_read failed for #%d/fd%d [i%d o%d]: %.100s", c->self, c->sock, c->istate, c->ostate, strerror(errno)); } -static void +void chan_delete_if_full_closed(Channel *c) { if (c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED) { @@ -27,7 +27,7 @@ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ -/* RCSID("$Id: nchan.h,v 1.3 1999/11/25 00:54:59 damien Exp $"); */ +/* RCSID("$Id: nchan.h,v 1.4 2000/04/01 01:09:24 damien Exp $"); */ #ifndef NCHAN_H #define NCHAN_H @@ -83,4 +83,6 @@ void chan_write_failed(Channel * c); void chan_obuf_empty(Channel * c); void chan_init_iostates(Channel * c); + +void chan_delete_if_full_closed(Channel *c); #endif @@ -15,7 +15,7 @@ */ #include "includes.h" -RCSID("$Id: packet.c,v 1.12 2000/03/09 10:27:50 damien Exp $"); +RCSID("$Id: packet.c,v 1.13 2000/04/01 01:09:25 damien Exp $"); #include "xmalloc.h" #include "buffer.h" @@ -28,6 +28,7 @@ RCSID("$Id: packet.c,v 1.12 2000/03/09 10:27:50 damien Exp $"); #include "compress.h" #include "deattack.h" +#include "channels.h" /* * This variable contains the file descriptors used for communicating with @@ -13,7 +13,7 @@ * tty. */ -/* RCSID("$Id: pty.h,v 1.6 2000/03/09 10:27:51 damien Exp $"); */ +/* RCSID("$Id: pty.h,v 1.7 2000/04/01 01:09:25 damien Exp $"); */ #ifndef PTY_H #define PTY_H @@ -45,6 +45,4 @@ pty_change_window_size(int ptyfd, int row, int col, void pty_setowner(struct passwd *pw, const char *ttyname); -void pty_setowner(struct passwd *pw, const char *ttyname); - #endif /* PTY_H */ diff --git a/readconf.c b/readconf.c index 99023d136..bb420ac05 100644 --- a/readconf.c +++ b/readconf.c @@ -14,11 +14,12 @@ */ #include "includes.h" -RCSID("$Id: readconf.c,v 1.8 2000/03/09 10:27:51 damien Exp $"); +RCSID("$Id: readconf.c,v 1.9 2000/04/01 01:09:25 damien Exp $"); #include "ssh.h" #include "cipher.h" #include "readconf.h" +#include "match.h" #include "xmalloc.h" /* Format of the configuration file: diff --git a/serverloop.c b/serverloop.c index 2afca7637..8bf448ceb 100644 --- a/serverloop.c +++ b/serverloop.c @@ -13,6 +13,10 @@ #include "buffer.h" #include "servconf.h" #include "pty.h" +#include "channels.h" + +#include "compat.h" +#include "dispatch.h" static Buffer stdin_buffer; /* Buffer for stdin data. */ static Buffer stdout_buffer; /* Buffer for stdout data. */ @@ -47,6 +51,8 @@ static volatile int child_terminated; /* The child has terminated. */ static volatile int child_has_selected; /* Child has had chance to drain. */ static volatile int child_wait_status; /* Status from wait(). */ +void server_init_dispatch(void); + void sigchld_handler(int sig) { @@ -68,104 +74,6 @@ sigchld_handler(int sig) } /* - * Process any buffered packets that have been received from the client. - */ -void -process_buffered_input_packets() -{ - int type; - char *data; - unsigned int data_len; - int row, col, xpixel, ypixel; - int payload_len; - - /* Process buffered packets from the client. */ - while ((type = packet_read_poll(&payload_len)) != SSH_MSG_NONE) { - switch (type) { - case SSH_CMSG_STDIN_DATA: - /* Stdin data from the client. Append it to the buffer. */ - /* Ignore any data if the client has closed stdin. */ - if (fdin == -1) - break; - data = packet_get_string(&data_len); - packet_integrity_check(payload_len, (4 + data_len), type); - buffer_append(&stdin_buffer, data, data_len); - memset(data, 0, data_len); - xfree(data); - break; - - case SSH_CMSG_EOF: - /* - * Eof from the client. The stdin descriptor to the - * program will be closed when all buffered data has - * drained. - */ - debug("EOF received for stdin."); - packet_integrity_check(payload_len, 0, type); - stdin_eof = 1; - break; - - case SSH_CMSG_WINDOW_SIZE: - debug("Window change received."); - packet_integrity_check(payload_len, 4 * 4, type); - row = packet_get_int(); - col = packet_get_int(); - xpixel = packet_get_int(); - ypixel = packet_get_int(); - if (fdin != -1) - pty_change_window_size(fdin, row, col, xpixel, ypixel); - break; - - case SSH_MSG_PORT_OPEN: - debug("Received port open request."); - channel_input_port_open(payload_len); - break; - - case SSH_MSG_CHANNEL_OPEN_CONFIRMATION: - debug("Received channel open confirmation."); - packet_integrity_check(payload_len, 4 + 4, type); - channel_input_open_confirmation(); - break; - - case SSH_MSG_CHANNEL_OPEN_FAILURE: - debug("Received channel open failure."); - packet_integrity_check(payload_len, 4, type); - channel_input_open_failure(); - break; - - case SSH_MSG_CHANNEL_DATA: - channel_input_data(payload_len); - break; - - case SSH_MSG_CHANNEL_CLOSE: - debug("Received channel close."); - packet_integrity_check(payload_len, 4, type); - channel_input_close(); - break; - - case SSH_MSG_CHANNEL_CLOSE_CONFIRMATION: - debug("Received channel close confirmation."); - packet_integrity_check(payload_len, 4, type); - channel_input_close_confirmation(); - break; - - default: - /* - * In this phase, any unexpected messages cause a - * protocol error. This is to ease debugging; also, - * since no confirmations are sent messages, - * unprocessed unknown messages could cause strange - * problems. Any compatible protocol extensions must - * be negotiated before entering the interactive - * session. - */ - packet_disconnect("Protocol error during session: type %d", - type); - } - } -} - -/* * Make packets from buffered stderr data, and buffer it for sending * to the client. */ @@ -378,7 +286,7 @@ process_output(fd_set * writeset) #ifdef USE_PIPES close(fdin); #else - if (fdout == -1) + if (fdin != fdout) close(fdin); else shutdown(fdin, SHUT_WR); /* We will no longer send. */ @@ -425,6 +333,12 @@ drain_output() packet_write_wait(); } +void +process_buffered_input_packets() +{ + dispatch_run(DISPATCH_NONBLOCK, NULL); +} + /* * Performs the interactive session. This handles data transmission between * the client and the program. Note that the notion of stdin, stdout, and @@ -490,6 +404,8 @@ server_loop(int pid, int fdin_arg, int fdout_arg, int fderr_arg) if (fderr == -1) fderr_eof = 1; + server_init_dispatch(); + /* Main loop of the server for the interactive session mode. */ for (;;) { fd_set readset, writeset; @@ -505,7 +421,7 @@ server_loop(int pid, int fdin_arg, int fdout_arg, int fderr_arg) #ifdef USE_PIPES close(fdin); #else - if (fdout == -1) + if (fdin != fdout) close(fdin); else shutdown(fdin, SHUT_WR); /* We will no longer send. */ @@ -549,7 +465,7 @@ server_loop(int pid, int fdin_arg, int fdout_arg, int fderr_arg) (buffer_len(&stdout_buffer) == 0) && (buffer_len(&stderr_buffer) == 0)) { if (!channel_still_open()) - goto quit; + break; if (!waiting_termination) { const char *s = "Waiting for forwarded connections to terminate...\r\n"; char *cp; @@ -576,7 +492,6 @@ server_loop(int pid, int fdin_arg, int fdout_arg, int fderr_arg) process_output(&writeset); } -quit: /* Cleanup and termination code. */ /* Wait until all output has been sent to the client. */ @@ -662,3 +577,79 @@ quit: packet_disconnect("wait returned status %04x.", wait_status); /* NOTREACHED */ } + +void +server_input_stdin_data(int type, int plen) +{ + char *data; + unsigned int data_len; + + /* Stdin data from the client. Append it to the buffer. */ + /* Ignore any data if the client has closed stdin. */ + if (fdin == -1) + return; + data = packet_get_string(&data_len); + packet_integrity_check(plen, (4 + data_len), type); + buffer_append(&stdin_buffer, data, data_len); + memset(data, 0, data_len); + xfree(data); +} + +void +server_input_eof(int type, int plen) +{ + /* + * Eof from the client. The stdin descriptor to the + * program will be closed when all buffered data has + * drained. + */ + debug("EOF received for stdin."); + packet_integrity_check(plen, 0, type); + stdin_eof = 1; +} + +void +server_input_window_size(int type, int plen) +{ + int row = packet_get_int(); + int col = packet_get_int(); + int xpixel = packet_get_int(); + int ypixel = packet_get_int(); + + debug("Window change received."); + packet_integrity_check(plen, 4 * 4, type); + if (fdin != -1) + pty_change_window_size(fdin, row, col, xpixel, ypixel); +} + +void +server_init_dispatch_13() +{ + debug("server_init_dispatch_13"); + dispatch_init(NULL); + dispatch_set(SSH_CMSG_EOF, &server_input_eof); + dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data); + dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size); + dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); + dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); + dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); + dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); + dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); + dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); +} +void +server_init_dispatch_15() +{ + server_init_dispatch_13(); + debug("server_init_dispatch_15"); + dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); + dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose); +} +void +server_init_dispatch() +{ + if (compat13) + server_init_dispatch_13(); + else + server_init_dispatch_15(); +} diff --git a/session.c b/session.c new file mode 100644 index 000000000..2128fe394 --- /dev/null +++ b/session.c @@ -0,0 +1,1153 @@ +/* + * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland + * All rights reserved + */ + +#include "includes.h" +RCSID("$OpenBSD: session.c,v 1.1 2000/03/28 21:15:45 markus Exp $"); + +#include "xmalloc.h" +#include "ssh.h" +#include "pty.h" +#include "packet.h" +#include "buffer.h" +#include "cipher.h" +#include "mpaux.h" +#include "servconf.h" +#include "uidswap.h" +#include "compat.h" +#include "channels.h" +#include "nchan.h" + +/* types */ + +#define TTYSZ 64 +typedef struct Session Session; +struct Session { + int used; + int self; + struct passwd *pw; + pid_t pid; + /* tty */ + char *term; + int ptyfd, ttyfd, ptymaster; + int row, col, xpixel, ypixel; + char tty[TTYSZ]; + /* X11 */ + char *display; + int screen; + char *auth_proto; + char *auth_data; + /* proto 2 */ + int chanid; +}; + +/* func */ + +Session *session_new(void); +void session_set_fds(Session *s, int fdin, int fdout, int fderr); +void session_pty_cleanup(Session *s); +void do_exec_pty(Session *s, const char *command, struct passwd * pw); +void do_exec_no_pty(Session *s, const char *command, struct passwd * pw); + +void +do_child(const char *command, struct passwd * pw, const char *term, + const char *display, const char *auth_proto, + const char *auth_data, const char *ttyname); + +/* import */ +extern ServerOptions options; +extern char *__progname; +extern int log_stderr; +extern int debug_flag; + +/* Local Xauthority file. */ +static char *xauthfile; + +/* data */ +#define MAX_SESSIONS 10 +Session sessions[MAX_SESSIONS]; + +/* Flags set in auth-rsa from authorized_keys flags. These are set in auth-rsa.c. */ +int no_port_forwarding_flag = 0; +int no_agent_forwarding_flag = 0; +int no_x11_forwarding_flag = 0; +int no_pty_flag = 0; + +/* RSA authentication "command=" option. */ +char *forced_command = NULL; + +/* RSA authentication "environment=" options. */ +struct envstring *custom_environment = NULL; + +/* + * Remove local Xauthority file. + */ +void +xauthfile_cleanup_proc(void *ignore) +{ + debug("xauthfile_cleanup_proc called"); + + if (xauthfile != NULL) { + char *p; + unlink(xauthfile); + p = strrchr(xauthfile, '/'); + if (p != NULL) { + *p = '\0'; + rmdir(xauthfile); + } + xfree(xauthfile); + xauthfile = NULL; + } +} + +/* + * Function to perform cleanup if we get aborted abnormally (e.g., due to a + * dropped connection). + */ +void +pty_cleanup_proc(void *session) +{ + Session *s=session; + if (s == NULL) + fatal("pty_cleanup_proc: no session"); + debug("pty_cleanup_proc: %s", s->tty); + + if (s->pid != 0) { + /* Record that the user has logged out. */ + record_logout(s->pid, s->tty); + } + + /* Release the pseudo-tty. */ + pty_release(s->tty); +} + +/* + * Prepares for an interactive session. This is called after the user has + * been successfully authenticated. During this message exchange, pseudo + * terminals are allocated, X11, TCP/IP, and authentication agent forwardings + * are requested, etc. + */ +void +do_authenticated(struct passwd * pw) +{ + Session *s; + int type; + int compression_level = 0, enable_compression_after_reply = 0; + int have_pty = 0; + char *command; + int n_bytes; + int plen; + unsigned int proto_len, data_len, dlen; + + /* + * Cancel the alarm we set to limit the time taken for + * authentication. + */ + alarm(0); + + /* + * Inform the channel mechanism that we are the server side and that + * the client may request to connect to any port at all. (The user + * could do it anyway, and we wouldn\'t know what is permitted except + * by the client telling us, so we can equally well trust the client + * not to request anything bogus.) + */ + if (!no_port_forwarding_flag) + channel_permit_all_opens(); + + s = session_new(); + + /* + * We stay in this loop until the client requests to execute a shell + * or a command. + */ + for (;;) { + int success = 0; + + /* Get a packet from the client. */ + type = packet_read(&plen); + + /* Process the packet. */ + switch (type) { + case SSH_CMSG_REQUEST_COMPRESSION: + packet_integrity_check(plen, 4, type); + compression_level = packet_get_int(); + if (compression_level < 1 || compression_level > 9) { + packet_send_debug("Received illegal compression level %d.", + compression_level); + break; + } + /* Enable compression after we have responded with SUCCESS. */ + enable_compression_after_reply = 1; + success = 1; + break; + + case SSH_CMSG_REQUEST_PTY: + if (no_pty_flag) { + debug("Allocating a pty not permitted for this authentication."); + break; + } + if (have_pty) + packet_disconnect("Protocol error: you already have a pty."); + + debug("Allocating pty."); + + /* Allocate a pty and open it. */ + if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, + sizeof(s->tty))) { + error("Failed to allocate pty."); + break; + } + fatal_add_cleanup(pty_cleanup_proc, (void *)s); + pty_setowner(pw, s->tty); + + /* Get TERM from the packet. Note that the value may be of arbitrary length. */ + s->term = packet_get_string(&dlen); + packet_integrity_check(dlen, strlen(s->term), type); + /* packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); */ + /* Remaining bytes */ + n_bytes = plen - (4 + dlen + 4 * 4); + + if (strcmp(s->term, "") == 0) { + xfree(s->term); + s->term = NULL; + } + /* Get window size from the packet. */ + s->row = packet_get_int(); + s->col = packet_get_int(); + s->xpixel = packet_get_int(); + s->ypixel = packet_get_int(); + pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); + + /* Get tty modes from the packet. */ + tty_parse_modes(s->ttyfd, &n_bytes); + packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type); + + /* Indicate that we now have a pty. */ + success = 1; + have_pty = 1; + break; + + case SSH_CMSG_X11_REQUEST_FORWARDING: + if (!options.x11_forwarding) { + packet_send_debug("X11 forwarding disabled in server configuration file."); + break; + } +#ifdef XAUTH_PATH + if (no_x11_forwarding_flag) { + packet_send_debug("X11 forwarding not permitted for this authentication."); + break; + } + debug("Received request for X11 forwarding with auth spoofing."); + if (s->display != NULL) + packet_disconnect("Protocol error: X11 display already set."); + + s->auth_proto = packet_get_string(&proto_len); + s->auth_data = packet_get_string(&data_len); + packet_integrity_check(plen, 4 + proto_len + 4 + data_len + 4, type); + + if (packet_get_protocol_flags() & SSH_PROTOFLAG_SCREEN_NUMBER) + s->screen = packet_get_int(); + else + s->screen = 0; + s->display = x11_create_display_inet(s->screen, options.x11_display_offset); + + if (s->display == NULL) + break; + + /* Setup to always have a local .Xauthority. */ + xauthfile = xmalloc(MAXPATHLEN); + strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN); + temporarily_use_uid(pw->pw_uid); + if (mkdtemp(xauthfile) == NULL) { + restore_uid(); + error("private X11 dir: mkdtemp %s failed: %s", + xauthfile, strerror(errno)); + xfree(xauthfile); + xauthfile = NULL; + break; + } + strlcat(xauthfile, "/cookies", MAXPATHLEN); + open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600); + restore_uid(); + fatal_add_cleanup(xauthfile_cleanup_proc, NULL); + success = 1; + break; +#else /* XAUTH_PATH */ + packet_send_debug("No xauth program; cannot forward with spoofing."); + break; +#endif /* XAUTH_PATH */ + + case SSH_CMSG_AGENT_REQUEST_FORWARDING: + if (no_agent_forwarding_flag || compat13) { + debug("Authentication agent forwarding not permitted for this authentication."); + break; + } + debug("Received authentication agent forwarding request."); + auth_input_request_forwarding(pw); + success = 1; + break; + + case SSH_CMSG_PORT_FORWARD_REQUEST: + if (no_port_forwarding_flag) { + debug("Port forwarding not permitted for this authentication."); + break; + } + debug("Received TCP/IP port forwarding request."); + channel_input_port_forward_request(pw->pw_uid == 0); + success = 1; + break; + + case SSH_CMSG_MAX_PACKET_SIZE: + if (packet_set_maxsize(packet_get_int()) > 0) + success = 1; + break; + + case SSH_CMSG_EXEC_SHELL: + case SSH_CMSG_EXEC_CMD: + /* Set interactive/non-interactive mode. */ + packet_set_interactive(have_pty || s->display != NULL, + options.keepalives); + + if (type == SSH_CMSG_EXEC_CMD) { + command = packet_get_string(&dlen); + debug("Exec command '%.500s'", command); + packet_integrity_check(plen, 4 + dlen, type); + } else { + command = NULL; + packet_integrity_check(plen, 0, type); + } + if (forced_command != NULL) { + command = forced_command; + debug("Forced command '%.500s'", forced_command); + } + if (have_pty) + do_exec_pty(s, command, pw); + else + do_exec_no_pty(s, command, pw); + + if (command != NULL) + xfree(command); + /* Cleanup user's local Xauthority file. */ + if (xauthfile) + xauthfile_cleanup_proc(NULL); + return; + + default: + /* + * Any unknown messages in this phase are ignored, + * and a failure message is returned. + */ + log("Unknown packet type received after authentication: %d", type); + } + packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE); + packet_send(); + packet_write_wait(); + + /* Enable compression now that we have replied if appropriate. */ + if (enable_compression_after_reply) { + enable_compression_after_reply = 0; + packet_start_compression(compression_level); + } + } +} + +/* + * This is called to fork and execute a command when we have no tty. This + * will call do_child from the child, and server_loop from the parent after + * setting up file descriptors and such. + */ +void +do_exec_no_pty(Session *s, const char *command, struct passwd * pw) +{ + int pid; + +#ifdef USE_PIPES + int pin[2], pout[2], perr[2]; + /* Allocate pipes for communicating with the program. */ + if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0) + packet_disconnect("Could not create pipes: %.100s", + strerror(errno)); +#else /* USE_PIPES */ + int inout[2], err[2]; + /* Uses socket pairs to communicate with the program. */ + if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 || + socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) + packet_disconnect("Could not create socket pairs: %.100s", + strerror(errno)); +#endif /* USE_PIPES */ + if (s == NULL) + fatal("do_exec_no_pty: no session"); + + setproctitle("%s@notty", pw->pw_name); + +#ifdef USE_PAM + do_pam_setcred(); +#endif /* USE_PAM */ + + /* Fork the child. */ + if ((pid = fork()) == 0) { + /* Child. Reinitialize the log since the pid has changed. */ + log_init(__progname, options.log_level, options.log_facility, log_stderr); + + /* + * Create a new session and process group since the 4.4BSD + * setlogin() affects the entire process group. + */ + if (setsid() < 0) + error("setsid failed: %.100s", strerror(errno)); + +#ifdef USE_PIPES + /* + * Redirect stdin. We close the parent side of the socket + * pair, and make the child side the standard input. + */ + close(pin[1]); + if (dup2(pin[0], 0) < 0) + perror("dup2 stdin"); + close(pin[0]); + + /* Redirect stdout. */ + close(pout[0]); + if (dup2(pout[1], 1) < 0) + perror("dup2 stdout"); + close(pout[1]); + + /* Redirect stderr. */ + close(perr[0]); + if (dup2(perr[1], 2) < 0) + perror("dup2 stderr"); + close(perr[1]); +#else /* USE_PIPES */ + /* + * Redirect stdin, stdout, and stderr. Stdin and stdout will + * use the same socket, as some programs (particularly rdist) + * seem to depend on it. + */ + close(inout[1]); + close(err[1]); + if (dup2(inout[0], 0) < 0) /* stdin */ + perror("dup2 stdin"); + if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */ + perror("dup2 stdout"); + if (dup2(err[0], 2) < 0) /* stderr */ + perror("dup2 stderr"); +#endif /* USE_PIPES */ + + /* Do processing for the child (exec command etc). */ + do_child(command, pw, NULL, s->display, s->auth_proto, s->auth_data, NULL); + /* NOTREACHED */ + } + if (pid < 0) + packet_disconnect("fork failed: %.100s", strerror(errno)); + s->pid = pid; +#ifdef USE_PIPES + /* We are the parent. Close the child sides of the pipes. */ + close(pin[0]); + close(pout[1]); + close(perr[1]); + + /* Enter the interactive session. */ + server_loop(pid, pin[1], pout[0], perr[0]); + /* server_loop has closed pin[1], pout[1], and perr[1]. */ +#else /* USE_PIPES */ + /* We are the parent. Close the child sides of the socket pairs. */ + close(inout[0]); + close(err[0]); + + /* + * Enter the interactive session. Note: server_loop must be able to + * handle the case that fdin and fdout are the same. + */ + server_loop(pid, inout[1], inout[1], err[1]); + /* server_loop has closed inout[1] and err[1]. */ +#endif /* USE_PIPES */ +} + +/* + * This is called to fork and execute a command when we have a tty. This + * will call do_child from the child, and server_loop from the parent after + * setting up file descriptors, controlling tty, updating wtmp, utmp, + * lastlog, and other such operations. + */ +void +do_exec_pty(Session *s, const char *command, struct passwd * pw) +{ + FILE *f; + char buf[100], *time_string; + char line[256]; + const char *hostname; + int fdout, ptyfd, ttyfd, ptymaster; + int quiet_login; + pid_t pid; + socklen_t fromlen; + struct sockaddr_storage from; + struct stat st; + time_t last_login_time; + + if (s == NULL) + fatal("do_exec_pty: no session"); + ptyfd = s->ptyfd; + ttyfd = s->ttyfd; + + /* Get remote host name. */ + hostname = get_canonical_hostname(); + + /* + * Get the time when the user last logged in. Buf will be set to + * contain the hostname the last login was from. + */ + if (!options.use_login) { + last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name, + buf, sizeof(buf)); + } + setproctitle("%s@%s", pw->pw_name, strrchr(s->tty, '/') + 1); + +#ifdef USE_PAM + do_pam_session(pw->pw_name, s->tty); + do_pam_setcred(); +#endif /* USE_PAM */ + + /* Fork the child. */ + if ((pid = fork()) == 0) { + pid = getpid(); + + /* Child. Reinitialize the log because the pid has + changed. */ + log_init(__progname, options.log_level, options.log_facility, log_stderr); + + /* Close the master side of the pseudo tty. */ + close(ptyfd); + + /* Make the pseudo tty our controlling tty. */ + pty_make_controlling_tty(&ttyfd, s->tty); + + /* Redirect stdin from the pseudo tty. */ + if (dup2(ttyfd, fileno(stdin)) < 0) + error("dup2 stdin failed: %.100s", strerror(errno)); + + /* Redirect stdout to the pseudo tty. */ + if (dup2(ttyfd, fileno(stdout)) < 0) + error("dup2 stdin failed: %.100s", strerror(errno)); + + /* Redirect stderr to the pseudo tty. */ + if (dup2(ttyfd, fileno(stderr)) < 0) + error("dup2 stdin failed: %.100s", strerror(errno)); + + /* Close the extra descriptor for the pseudo tty. */ + close(ttyfd); + +///XXXX ? move to do_child() ?? + /* + * Get IP address of client. This is needed because we want + * to record where the user logged in from. If the + * connection is not a socket, let the ip address be 0.0.0.0. + */ + memset(&from, 0, sizeof(from)); + if (packet_connection_is_on_socket()) { + fromlen = sizeof(from); + if (getpeername(packet_get_connection_in(), + (struct sockaddr *) & from, &fromlen) < 0) { + debug("getpeername: %.100s", strerror(errno)); + fatal_cleanup(); + } + } + /* Record that there was a login on that terminal. */ + record_login(pid, s->tty, pw->pw_name, pw->pw_uid, hostname, + (struct sockaddr *)&from); + + /* Check if .hushlogin exists. */ + snprintf(line, sizeof line, "%.200s/.hushlogin", pw->pw_dir); + quiet_login = stat(line, &st) >= 0; + +#ifdef USE_PAM + if (!quiet_login) + print_pam_messages(); +#endif /* USE_PAM */ + + /* + * If the user has logged in before, display the time of last + * login. However, don't display anything extra if a command + * has been specified (so that ssh can be used to execute + * commands on a remote machine without users knowing they + * are going to another machine). Login(1) will do this for + * us as well, so check if login(1) is used + */ + if (command == NULL && last_login_time != 0 && !quiet_login && + !options.use_login) { + /* Convert the date to a string. */ + time_string = ctime(&last_login_time); + /* Remove the trailing newline. */ + if (strchr(time_string, '\n')) + *strchr(time_string, '\n') = 0; + /* Display the last login time. Host if displayed + if known. */ + if (strcmp(buf, "") == 0) + printf("Last login: %s\r\n", time_string); + else + printf("Last login: %s from %s\r\n", time_string, buf); + } + /* + * Print /etc/motd unless a command was specified or printing + * it was disabled in server options or login(1) will be + * used. Note that some machines appear to print it in + * /etc/profile or similar. + */ + if (command == NULL && options.print_motd && !quiet_login && + !options.use_login) { + /* Print /etc/motd if it exists. */ + f = fopen("/etc/motd", "r"); + if (f) { + while (fgets(line, sizeof(line), f)) + fputs(line, stdout); + fclose(f); + } + } + /* Do common processing for the child, such as execing the command. */ + do_child(command, pw, s->term, s->display, s->auth_proto, s->auth_data, s->tty); + /* NOTREACHED */ + } + if (pid < 0) + packet_disconnect("fork failed: %.100s", strerror(errno)); + s->pid = pid; + + /* Parent. Close the slave side of the pseudo tty. */ + close(ttyfd); + + /* + * Create another descriptor of the pty master side for use as the + * standard input. We could use the original descriptor, but this + * simplifies code in server_loop. The descriptor is bidirectional. + */ + fdout = dup(ptyfd); + if (fdout < 0) + packet_disconnect("dup #1 failed: %.100s", strerror(errno)); + + /* we keep a reference to the pty master */ + ptymaster = dup(ptyfd); + if (ptymaster < 0) + packet_disconnect("dup #2 failed: %.100s", strerror(errno)); + s->ptymaster = ptymaster; + + /* Enter interactive session. */ + server_loop(pid, ptyfd, fdout, -1); + /* server_loop _has_ closed ptyfd and fdout. */ + session_pty_cleanup(s); +} + +/* + * Sets the value of the given variable in the environment. If the variable + * already exists, its value is overriden. + */ +void +child_set_env(char ***envp, unsigned int *envsizep, const char *name, + const char *value) +{ + unsigned int i, namelen; + char **env; + + /* + * Find the slot where the value should be stored. If the variable + * already exists, we reuse the slot; otherwise we append a new slot + * at the end of the array, expanding if necessary. + */ + env = *envp; + namelen = strlen(name); + for (i = 0; env[i]; i++) + if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') + break; + if (env[i]) { + /* Reuse the slot. */ + xfree(env[i]); + } else { + /* New variable. Expand if necessary. */ + if (i >= (*envsizep) - 1) { + (*envsizep) += 50; + env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *)); + } + /* Need to set the NULL pointer at end of array beyond the new slot. */ + env[i + 1] = NULL; + } + + /* Allocate space and format the variable in the appropriate slot. */ + env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); + snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); +} + +/* + * Reads environment variables from the given file and adds/overrides them + * into the environment. If the file does not exist, this does nothing. + * Otherwise, it must consist of empty lines, comments (line starts with '#') + * and assignments of the form name=value. No other forms are allowed. + */ +void +read_environment_file(char ***env, unsigned int *envsize, + const char *filename) +{ + FILE *f; + char buf[4096]; + char *cp, *value; + + f = fopen(filename, "r"); + if (!f) + return; + + while (fgets(buf, sizeof(buf), f)) { + for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) + ; + if (!*cp || *cp == '#' || *cp == '\n') + continue; + if (strchr(cp, '\n')) + *strchr(cp, '\n') = '\0'; + value = strchr(cp, '='); + if (value == NULL) { + fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf); + continue; + } + /* Replace the equals sign by nul, and advance value to the value string. */ + *value = '\0'; + value++; + child_set_env(env, envsize, cp, value); + } + fclose(f); +} + +#ifdef USE_PAM +/* + * Sets any environment variables which have been specified by PAM + */ +void do_pam_environment(char ***env, int *envsize) +{ + char *equals, var_name[512], var_val[512]; + char **pam_env; + int i; + + if ((pam_env = fetch_pam_environment()) == NULL) + return; + + for(i = 0; pam_env[i] != NULL; i++) { + if ((equals = strstr(pam_env[i], "=")) == NULL) + continue; + + if (strlen(pam_env[i]) < (sizeof(var_name) - 1)) { + memset(var_name, '\0', sizeof(var_name)); + memset(var_val, '\0', sizeof(var_val)); + + strncpy(var_name, pam_env[i], equals - pam_env[i]); + strcpy(var_val, equals + 1); + + debug("PAM environment: %s=%s", var_name, var_val); + + child_set_env(env, envsize, var_name, var_val); + } + } +} +#endif /* USE_PAM */ + +/* + * Performs common processing for the child, such as setting up the + * environment, closing extra file descriptors, setting the user and group + * ids, and executing the command or shell. + */ +void +do_child(const char *command, struct passwd * pw, const char *term, + const char *display, const char *auth_proto, + const char *auth_data, const char *ttyname) +{ + const char *shell, *cp = NULL; + char buf[256]; + FILE *f; + unsigned int envsize, i; + char **env; + extern char **environ; + struct stat st; + char *argv[10]; + +#ifndef USE_PAM /* pam_nologin handles this */ + f = fopen("/etc/nologin", "r"); + if (f) { + /* /etc/nologin exists. Print its contents and exit. */ + while (fgets(buf, sizeof(buf), f)) + fputs(buf, stderr); + fclose(f); + if (pw->pw_uid != 0) + exit(254); + } +#endif /* USE_PAM */ + + /* Set login name in the kernel. */ + if (setlogin(pw->pw_name) < 0) + error("setlogin failed: %s", strerror(errno)); + + /* Set uid, gid, and groups. */ + /* Login(1) does this as well, and it needs uid 0 for the "-h" + switch, so we let login(1) to this for us. */ + if (!options.use_login) { + if (getuid() == 0 || geteuid() == 0) { + if (setgid(pw->pw_gid) < 0) { + perror("setgid"); + exit(1); + } + /* Initialize the group list. */ + if (initgroups(pw->pw_name, pw->pw_gid) < 0) { + perror("initgroups"); + exit(1); + } + endgrent(); + + /* Permanently switch to the desired uid. */ + permanently_set_uid(pw->pw_uid); + } + if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) + fatal("Failed to set uids to %d.", (int) pw->pw_uid); + } + /* + * Get the shell from the password data. An empty shell field is + * legal, and means /bin/sh. + */ + shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; + +#ifdef AFS + /* Try to get AFS tokens for the local cell. */ + if (k_hasafs()) { + char cell[64]; + + if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) + krb_afslog(cell, 0); + + krb_afslog(0, 0); + } +#endif /* AFS */ + + /* Initialize the environment. */ + envsize = 100; + env = xmalloc(envsize * sizeof(char *)); + env[0] = NULL; + + if (!options.use_login) { + /* Set basic environment. */ + child_set_env(&env, &envsize, "USER", pw->pw_name); + child_set_env(&env, &envsize, "LOGNAME", pw->pw_name); + child_set_env(&env, &envsize, "HOME", pw->pw_dir); + child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); + + snprintf(buf, sizeof buf, "%.200s/%.50s", + _PATH_MAILDIR, pw->pw_name); + child_set_env(&env, &envsize, "MAIL", buf); + + /* Normal systems set SHELL by default. */ + child_set_env(&env, &envsize, "SHELL", shell); + } + if (getenv("TZ")) + child_set_env(&env, &envsize, "TZ", getenv("TZ")); + + /* Set custom environment options from RSA authentication. */ + while (custom_environment) { + struct envstring *ce = custom_environment; + char *s = ce->s; + int i; + for (i = 0; s[i] != '=' && s[i]; i++); + if (s[i] == '=') { + s[i] = 0; + child_set_env(&env, &envsize, s, s + i + 1); + } + custom_environment = ce->next; + xfree(ce->s); + xfree(ce); + } + + snprintf(buf, sizeof buf, "%.50s %d %d", + get_remote_ipaddr(), get_remote_port(), get_local_port()); + child_set_env(&env, &envsize, "SSH_CLIENT", buf); + + if (ttyname) + child_set_env(&env, &envsize, "SSH_TTY", ttyname); + if (term) + child_set_env(&env, &envsize, "TERM", term); + if (display) + child_set_env(&env, &envsize, "DISPLAY", display); + +#ifdef _AIX + { + char *authstate,*krb5cc; + + if ((authstate = getenv("AUTHSTATE")) != NULL) + child_set_env(&env,&envsize,"AUTHSTATE",authstate); + + if ((krb5cc = getenv("KRB5CCNAME")) != NULL) + child_set_env(&env,&envsize,"KRB5CCNAME",krb5cc); + } +#endif + +#ifdef KRB4 + { + extern char *ticket; + + if (ticket) + child_set_env(&env, &envsize, "KRBTKFILE", ticket); + } +#endif /* KRB4 */ + +#ifdef USE_PAM + /* Pull in any environment variables that may have been set by PAM. */ + do_pam_environment(&env, &envsize); +#endif /* USE_PAM */ + + read_environment_file(&env,&envsize,"/etc/environment"); + + if (xauthfile) + child_set_env(&env, &envsize, "XAUTHORITY", xauthfile); + if (auth_get_socket_name() != NULL) + child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, + auth_get_socket_name()); + + /* read $HOME/.ssh/environment. */ + if (!options.use_login) { + snprintf(buf, sizeof buf, "%.200s/.ssh/environment", pw->pw_dir); + read_environment_file(&env, &envsize, buf); + } + if (debug_flag) { + /* dump the environment */ + fprintf(stderr, "Environment:\n"); + for (i = 0; env[i]; i++) + fprintf(stderr, " %.200s\n", env[i]); + } + /* + * Close the connection descriptors; note that this is the child, and + * the server will still have the socket open, and it is important + * that we do not shutdown it. Note that the descriptors cannot be + * closed before building the environment, as we call + * get_remote_ipaddr there. + */ + if (packet_get_connection_in() == packet_get_connection_out()) + close(packet_get_connection_in()); + else { + close(packet_get_connection_in()); + close(packet_get_connection_out()); + } + /* + * Close all descriptors related to channels. They will still remain + * open in the parent. + */ + /* XXX better use close-on-exec? -markus */ + channel_close_all(); + + /* + * Close any extra file descriptors. Note that there may still be + * descriptors left by system functions. They will be closed later. + */ + endpwent(); + + /* + * Close any extra open file descriptors so that we don\'t have them + * hanging around in clients. Note that we want to do this after + * initgroups, because at least on Solaris 2.3 it leaves file + * descriptors open. + */ + for (i = 3; i < 64; i++) + close(i); + + /* Change current directory to the user\'s home directory. */ + if (chdir(pw->pw_dir) < 0) + fprintf(stderr, "Could not chdir to home directory %s: %s\n", + pw->pw_dir, strerror(errno)); + + /* + * Must take new environment into use so that .ssh/rc, /etc/sshrc and + * xauth are run in the proper environment. + */ + environ = env; + + /* + * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first + * in this order). + */ + if (!options.use_login) { + if (stat(SSH_USER_RC, &st) >= 0) { + if (debug_flag) + fprintf(stderr, "Running /bin/sh %s\n", SSH_USER_RC); + + f = popen("/bin/sh " SSH_USER_RC, "w"); + if (f) { + if (auth_proto != NULL && auth_data != NULL) + fprintf(f, "%s %s\n", auth_proto, auth_data); + pclose(f); + } else + fprintf(stderr, "Could not run %s\n", SSH_USER_RC); + } else if (stat(SSH_SYSTEM_RC, &st) >= 0) { + if (debug_flag) + fprintf(stderr, "Running /bin/sh %s\n", SSH_SYSTEM_RC); + + f = popen("/bin/sh " SSH_SYSTEM_RC, "w"); + if (f) { + if (auth_proto != NULL && auth_data != NULL) + fprintf(f, "%s %s\n", auth_proto, auth_data); + pclose(f); + } else + fprintf(stderr, "Could not run %s\n", SSH_SYSTEM_RC); + } +#ifdef XAUTH_PATH + else { + /* Add authority data to .Xauthority if appropriate. */ + if (auth_proto != NULL && auth_data != NULL) { + if (debug_flag) + fprintf(stderr, "Running %.100s add %.100s %.100s %.100s\n", + XAUTH_PATH, display, auth_proto, auth_data); + + f = popen(XAUTH_PATH " -q -", "w"); + if (f) { + fprintf(f, "add %s %s %s\n", display, auth_proto, auth_data); + pclose(f); + } else + fprintf(stderr, "Could not run %s -q -\n", XAUTH_PATH); + } + } +#endif /* XAUTH_PATH */ + + /* Get the last component of the shell name. */ + cp = strrchr(shell, '/'); + if (cp) + cp++; + else + cp = shell; + } + /* + * If we have no command, execute the shell. In this case, the shell + * name to be passed in argv[0] is preceded by '-' to indicate that + * this is a login shell. + */ + if (!command) { + if (!options.use_login) { + char buf[256]; + + /* + * Check for mail if we have a tty and it was enabled + * in server options. + */ + if (ttyname && options.check_mail) { + char *mailbox; + struct stat mailstat; + mailbox = getenv("MAIL"); + if (mailbox != NULL) { + if (stat(mailbox, &mailstat) != 0 || mailstat.st_size == 0) + printf("No mail.\n"); + else if (mailstat.st_mtime < mailstat.st_atime) + printf("You have mail.\n"); + else + printf("You have new mail.\n"); + } + } + /* Start the shell. Set initial character to '-'. */ + buf[0] = '-'; + strncpy(buf + 1, cp, sizeof(buf) - 1); + buf[sizeof(buf) - 1] = 0; + + /* Execute the shell. */ + argv[0] = buf; + argv[1] = NULL; + execve(shell, argv, env); + + /* Executing the shell failed. */ + perror(shell); + exit(1); + + } else { + /* Launch login(1). */ + + execl("/usr/bin/login", "login", "-h", get_remote_ipaddr(), + "-p", "-f", "--", pw->pw_name, NULL); + + /* Login couldn't be executed, die. */ + + perror("login"); + exit(1); + } + } + /* + * Execute the command using the user's shell. This uses the -c + * option to execute the command. + */ + argv[0] = (char *) cp; + argv[1] = "-c"; + argv[2] = (char *) command; + argv[3] = NULL; + execve(shell, argv, env); + perror(shell); + exit(1); +} + +Session * +session_new(void) +{ + int i; + static int did_init = 0; + if (!did_init) { + debug("session_new: init"); + for(i = 0; i < MAX_SESSIONS; i++) { + sessions[i].used = 0; + sessions[i].self = i; + } + did_init = 1; + } + for(i = 0; i < MAX_SESSIONS; i++) { + Session *s = &sessions[i]; + if (! s->used) { + s->pid = 0; + s->chanid = -1; + s->ptyfd = -1; + s->ttyfd = -1; + s->term = NULL; + s->pw = NULL; + s->display = NULL; + s->screen = 0; + s->auth_data = NULL; + s->auth_proto = NULL; + s->used = 1; + debug("session_new: session %d", i); + return s; + } + } + return NULL; +} + +void +session_dump(void) +{ + int i; + for(i = 0; i < MAX_SESSIONS; i++) { + Session *s = &sessions[i]; + debug("dump: used %d session %d %p channel %d pid %d", + s->used, + s->self, + s, + s->chanid, + s->pid); + } +} + +void +session_pty_cleanup(Session *s) +{ + if (s == NULL || s->ttyfd == -1) + return; + + debug("session_pty_cleanup: session %i release %s", s->self, s->tty); + + /* Cancel the cleanup function. */ + fatal_remove_cleanup(pty_cleanup_proc, (void *)s); + + /* Record that the user has logged out. */ + record_logout(s->pid, s->tty); + + /* Release the pseudo-tty. */ + pty_release(s->tty); + + /* + * Close the server side of the socket pairs. We must do this after + * the pty cleanup, so that another process doesn't get this pty + * while we're still cleaning up. + */ + if (close(s->ptymaster) < 0) + error("close(s->ptymaster): %s", strerror(errno)); +} diff --git a/session.h b/session.h new file mode 100644 index 000000000..2051b737d --- /dev/null +++ b/session.h @@ -0,0 +1,7 @@ +#ifndef SESSION_H +#define SESSION_H + +/* SSH1 */ +void do_authenticated(struct passwd * pw); + +#endif @@ -11,7 +11,7 @@ */ #include "includes.h" -RCSID("$Id: ssh.c,v 1.22 2000/03/26 03:04:54 damien Exp $"); +RCSID("$Id: ssh.c,v 1.23 2000/04/01 01:09:26 damien Exp $"); #include "xmalloc.h" #include "ssh.h" @@ -20,6 +20,7 @@ RCSID("$Id: ssh.c,v 1.22 2000/03/26 03:04:54 damien Exp $"); #include "authfd.h" #include "readconf.h" #include "uidswap.h" +#include "channels.h" #ifdef HAVE___PROGNAME extern char *__progname; @@ -13,7 +13,7 @@ * */ -/* RCSID("$Id: ssh.h,v 1.28 2000/03/26 03:04:54 damien Exp $"); */ +/* RCSID("$Id: ssh.h,v 1.29 2000/04/01 01:09:26 damien Exp $"); */ #ifndef SSH_H #define SSH_H @@ -486,175 +486,6 @@ void fatal_add_cleanup(void (*proc) (void *context), void *context); /* Removes a cleanup function to be called at fatal(). */ void fatal_remove_cleanup(void (*proc) (void *context), void *context); -/*---------------- definitions for channels ------------------*/ - -/* Sets specific protocol options. */ -void channel_set_options(int hostname_in_open); - -/* - * Allocate a new channel object and set its type and socket. Remote_name - * must have been allocated with xmalloc; this will free it when the channel - * is freed. - */ -int channel_allocate(int type, int sock, char *remote_name); - -/* Free the channel and close its socket. */ -void channel_free(int channel); - -/* Add any bits relevant to channels in select bitmasks. */ -void channel_prepare_select(fd_set * readset, fd_set * writeset); - -/* - * After select, perform any appropriate operations for channels which have - * events pending. - */ -void channel_after_select(fd_set * readset, fd_set * writeset); - -/* If there is data to send to the connection, send some of it now. */ -void channel_output_poll(void); - -/* - * This is called when a packet of type CHANNEL_DATA has just been received. - * The message type has already been consumed, but channel number and data is - * still there. - */ -void channel_input_data(int payload_len); - -/* Returns true if no channel has too much buffered data. */ -int channel_not_very_much_buffered_data(void); - -/* This is called after receiving CHANNEL_CLOSE. */ -void channel_input_close(void); - -/* This is called after receiving CHANNEL_CLOSE_CONFIRMATION. */ -void channel_input_close_confirmation(void); - -/* This is called after receiving CHANNEL_OPEN_CONFIRMATION. */ -void channel_input_open_confirmation(void); - -/* This is called after receiving CHANNEL_OPEN_FAILURE from the other side. */ -void channel_input_open_failure(void); - -/* This closes any sockets that are listening for connections; this removes - any unix domain sockets. */ -void channel_stop_listening(void); - -/* - * Closes the sockets of all channels. This is used to close extra file - * descriptors after a fork. - */ -void channel_close_all(void); - -/* Returns the maximum file descriptor number used by the channels. */ -int channel_max_fd(void); - -/* Returns true if there is still an open channel over the connection. */ -int channel_still_open(void); - -/* - * Returns a string containing a list of all open channels. The list is - * suitable for displaying to the user. It uses crlf instead of newlines. - * The caller should free the string with xfree. - */ -char *channel_open_message(void); - -/* - * Initiate forwarding of connections to local port "port" through the secure - * channel to host:port from remote side. This never returns if there was an - * error. - */ -void -channel_request_local_forwarding(u_short port, const char *host, - u_short remote_port, int gateway_ports); - -/* - * Initiate forwarding of connections to port "port" on remote host through - * the secure channel to host:port from local side. This never returns if - * there was an error. This registers that open requests for that port are - * permitted. - */ -void -channel_request_remote_forwarding(u_short port, const char *host, - u_short remote_port); - -/* - * Permits opening to any host/port in SSH_MSG_PORT_OPEN. This is usually - * called by the server, because the user could connect to any port anyway, - * and the server has no way to know but to trust the client anyway. - */ -void channel_permit_all_opens(void); - -/* - * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates - * listening for the port, and sends back a success reply (or disconnect - * message if there was an error). This never returns if there was an error. - */ -void channel_input_port_forward_request(int is_root); - -/* - * This is called after receiving PORT_OPEN message. This attempts to - * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION - * or CHANNEL_OPEN_FAILURE. - */ -void channel_input_port_open(int payload_len); - -/* - * Creates a port for X11 connections, and starts listening for it. Returns - * the display name, or NULL if an error was encountered. - */ -char *x11_create_display(int screen); - -/* - * Creates an internet domain socket for listening for X11 connections. - * Returns a suitable value for the DISPLAY variable, or NULL if an error - * occurs. - */ -char *x11_create_display_inet(int screen, int x11_display_offset); - -/* - * This is called when SSH_SMSG_X11_OPEN is received. The packet contains - * the remote channel number. We should do whatever we want, and respond - * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE. - */ -void x11_input_open(int payload_len); - -/* - * Requests forwarding of X11 connections. This should be called on the - * client only. - */ -void x11_request_forwarding(void); - -/* - * Requests forwarding for X11 connections, with authentication spoofing. - * This should be called in the client only. - */ -void x11_request_forwarding_with_spoofing(const char *proto, const char *data); - -/* Sends a message to the server to request authentication fd forwarding. */ -void auth_request_forwarding(void); - -/* - * Returns the name of the forwarded authentication socket. Returns NULL if - * there is no forwarded authentication socket. The returned value points to - * a static buffer. - */ -char *auth_get_socket_name(void); - -/* - * This if called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server. - * This starts forwarding authentication requests. - */ -void auth_input_request_forwarding(struct passwd * pw); - -/* This is called to process an SSH_SMSG_AGENT_OPEN message. */ -void auth_input_open_request(void); - -/* - * Returns true if the given string matches the pattern (which may contain ? - * and * as wildcards), and zero if it does not match. - */ -int match_pattern(const char *s, const char *pattern); - /* * Expands tildes in the file name. Returns data allocated by xmalloc. * Warning: this calls getpw*. @@ -0,0 +1,106 @@ +/* + * draft-ietf-secsh-architecture-04.txt + * + * Transport layer protocol: + * + * 1-19 Transport layer generic (e.g. disconnect, ignore, debug, + * etc) + * 20-29 Algorithm negotiation + * 30-49 Key exchange method specific (numbers can be reused for + * different authentication methods) + * + * User authentication protocol: + * + * 50-59 User authentication generic + * 60-79 User authentication method specific (numbers can be reused + * for different authentication methods) + * + * Connection protocol: + * + * 80-89 Connection protocol generic + * 90-127 Channel related messages + * + * Reserved for client protocols: + * + * 128-191 Reserved + * + * Local extensions: + * + * 192-255 Local extensions + */ + +/* transport layer: generic */ + +#define SSH2_MSG_DISCONNECT 1 +#define SSH2_MSG_IGNORE 2 +#define SSH2_MSG_UNIMPLEMENTED 3 +#define SSH2_MSG_DEBUG 4 +#define SSH2_MSG_SERVICE_REQUEST 5 +#define SSH2_MSG_SERVICE_ACCEPT 6 + +/* transport layer: alg negotiation */ + +#define SSH2_MSG_KEXINIT 20 +#define SSH2_MSG_NEWKEYS 21 + +/* transport layer: kex specific messages, can be reused */ + +#define SSH2_MSG_KEXDH_INIT 30 +#define SSH2_MSG_KEXDH_REPLY 31 + +/* user authentication: generic */ + +#define SSH2_MSG_USERAUTH_REQUEST 50 +#define SSH2_MSG_USERAUTH_FAILURE 51 +#define SSH2_MSG_USERAUTH_SUCCESS 52 +#define SSH2_MSG_USERAUTH_BANNER 53 + +/* user authentication: method specific, can be reused */ + +#define SSH2_MSG_USERAUTH_PK_OK 60 +#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 +#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 +#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 + +/* connection protocol: generic */ + +#define SSH2_MSG_GLOBAL_REQUEST 80 +#define SSH2_MSG_REQUEST_SUCCESS 81 +#define SSH2_MSG_REQUEST_FAILURE 82 + +/* channel related messages */ + +#define SSH2_MSG_CHANNEL_OPEN 90 +#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 +#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 +#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 +#define SSH2_MSG_CHANNEL_DATA 94 +#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 +#define SSH2_MSG_CHANNEL_EOF 96 +#define SSH2_MSG_CHANNEL_CLOSE 97 +#define SSH2_MSG_CHANNEL_REQUEST 98 +#define SSH2_MSG_CHANNEL_SUCCESS 99 +#define SSH2_MSG_CHANNEL_FAILURE 100 + +/* disconnect reason code */ + +#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 +#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 +#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 +#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 +#define SSH2_DISCONNECT_MAC_ERROR 5 +#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 +#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 +#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 +#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 +#define SSH2_DISCONNECT_CONNECTION_LOST 10 +#define SSH2_DISCONNECT_BY_APPLICATION 11 + +/* misc */ + +#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 +#define SSH2_OPEN_CONNECT_FAILED 2 +#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 +#define SSH2_OPEN_RESOURCE_SHORTAGE 4 + +#define SSH2_EXTENDED_DATA_STDERR 1 @@ -9,7 +9,7 @@ .\" .\" Created: Sat Apr 22 21:55:14 1995 ylo .\" -.\" $Id: sshd.8,v 1.15 2000/03/26 03:04:55 damien Exp $ +.\" $Id: sshd.8,v 1.16 2000/04/01 01:09:27 damien Exp $ .\" .Dd September 25, 1999 .Dt SSHD 8 @@ -69,7 +69,7 @@ random number as a session key which is used to encrypt all further communications in the session. The rest of the session is encrypted using a conventional cipher, currently Blowfish and 3DES, with 3DES -being is used by default. +being used by default. The client selects the encryption algorithm to use from those offered by the server. .Pp @@ -877,11 +877,11 @@ The libraries described in .Xr ssl 8 are required for proper operation. .Sh SEE ALSO -.Xr rlogin 1 , -.Xr rsh 1 , .Xr scp 1 , .Xr ssh 1 , .Xr ssh-add 1 , .Xr ssh-agent 1 , .Xr ssh-keygen 1 , -.Xr ssl 8 +.Xr ssl 8 , +.Xr rlogin 1 , +.Xr rsh 1 @@ -11,19 +11,37 @@ */ #include "includes.h" -RCSID("$OpenBSD: sshd.c,v 1.94 2000/03/23 22:15:34 markus Exp $"); +RCSID("$OpenBSD: sshd.c,v 1.96 2000/03/28 21:15:45 markus Exp $"); #include "xmalloc.h" #include "rsa.h" #include "ssh.h" #include "pty.h" #include "packet.h" -#include "buffer.h" #include "cipher.h" #include "mpaux.h" #include "servconf.h" #include "uidswap.h" #include "compat.h" +#include "buffer.h" + +#ifdef HAVE_OPENSSL +# include <openssl/dh.h> +# include <openssl/bn.h> +# include <openssl/hmac.h> +# include <openssl/dsa.h> +# include <openssl/rsa.h> +#endif +#ifdef HAVE_SSL +# include <ssl/dh.h> +# include <ssl/bn.h> +# include <ssl/hmac.h> +# include <ssl/dsa.h> +# include <ssl/rsa.h> +#endif +#include "key.h" + +#include "auth.h" #ifdef LIBWRAP #include <tcpd.h> @@ -36,9 +54,6 @@ int deny_severity = LOG_WARNING; #define O_NOCTTY 0 #endif -/* Local Xauthority file. */ -static char *xauthfile = NULL; - /* Server configuration options. */ ServerOptions options; @@ -88,21 +103,7 @@ int num_listen_socks = 0; * sshd will skip the version-number exchange */ char *client_version_string = NULL; - -/* Flags set in auth-rsa from authorized_keys flags. These are set in auth-rsa.c. */ -int no_port_forwarding_flag = 0; -int no_agent_forwarding_flag = 0; -int no_x11_forwarding_flag = 0; -int no_pty_flag = 0; - -/* RSA authentication "command=" option. */ -char *forced_command = NULL; - -/* RSA authentication "environment=" options. */ -struct envstring *custom_environment = NULL; - -/* Session id for the current session. */ -unsigned char session_id[16]; +char *server_version_string = NULL; /* * Any really sensitive data in the application is contained in this @@ -130,43 +131,11 @@ int received_sighup = 0; the private key. */ RSA *public_key; -/* Prototypes for various functions defined later in this file. */ -void do_ssh_kex(); -void do_authentication(); -void do_authloop(struct passwd * pw); -void do_fake_authloop(char *user); -void do_authenticated(struct passwd * pw); -void do_exec_pty(const char *command, int ptyfd, int ttyfd, - const char *ttyname, struct passwd * pw, const char *term, - const char *display, const char *auth_proto, - const char *auth_data); -void do_exec_no_pty(const char *command, struct passwd * pw, - const char *display, const char *auth_proto, - const char *auth_data); -void do_child(const char *command, struct passwd * pw, const char *term, - const char *display, const char *auth_proto, - const char *auth_data, const char *ttyname); +/* session identifier, used by RSA-auth */ +unsigned char session_id[16]; -/* - * Remove local Xauthority file. - */ -void -xauthfile_cleanup_proc(void *ignore) -{ - debug("xauthfile_cleanup_proc called"); - - if (xauthfile != NULL) { - char *p; - unlink(xauthfile); - p = strrchr(xauthfile, '/'); - if (p != NULL) { - *p = '\0'; - rmdir(xauthfile); - } - xfree(xauthfile); - xauthfile = NULL; - } -} +/* Prototypes for various functions defined later in this file. */ +void do_ssh1_kex(); /* * Close all listening sockets @@ -250,35 +219,6 @@ grace_alarm_handler(int sig) } /* - * convert ssh auth msg type into description - */ -char * -get_authname(int type) -{ - static char buf[1024]; - switch (type) { - case SSH_CMSG_AUTH_PASSWORD: - return "password"; - case SSH_CMSG_AUTH_RSA: - return "rsa"; - case SSH_CMSG_AUTH_RHOSTS_RSA: - return "rhosts-rsa"; - case SSH_CMSG_AUTH_RHOSTS: - return "rhosts"; -#ifdef KRB4 - case SSH_CMSG_AUTH_KERBEROS: - return "kerberos"; -#endif -#ifdef SKEY - case SSH_CMSG_AUTH_TIS_RESPONSE: - return "s/key"; -#endif - } - snprintf(buf, sizeof buf, "bad-auth-msg-%d", type); - return buf; -} - -/* * Signal handler for the key regeneration alarm. Note that this * alarm only occurs in the daemon waiting for connections, and it does not * do anything with the private key or random state before forking. @@ -315,6 +255,88 @@ key_regeneration_alarm(int sig) errno = save_errno; } +void +sshd_exchange_identification(int sock_in, int sock_out) +{ + int i; + int remote_major, remote_minor; + char *s; + char buf[256]; /* Must not be larger than remote_version. */ + char remote_version[256]; /* Must be at least as big as buf. */ + + snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", + PROTOCOL_MAJOR, PROTOCOL_MINOR, SSH_VERSION); + server_version_string = xstrdup(buf); + + if (client_version_string == NULL) { + /* Send our protocol version identification. */ + if (atomicio(write, sock_out, server_version_string, strlen(server_version_string)) + != strlen(server_version_string)) { + log("Could not write ident string to %s.", get_remote_ipaddr()); + fatal_cleanup(); + } + + /* Read other side\'s version identification. */ + for (i = 0; i < sizeof(buf) - 1; i++) { + if (read(sock_in, &buf[i], 1) != 1) { + log("Did not receive ident string from %s.", get_remote_ipaddr()); + fatal_cleanup(); + } + if (buf[i] == '\r') { + buf[i] = '\n'; + buf[i + 1] = 0; + continue; + /*break; XXX eat \r */ + } + if (buf[i] == '\n') { + /* buf[i] == '\n' */ + buf[i + 1] = 0; + break; + } + } + buf[sizeof(buf) - 1] = 0; + client_version_string = xstrdup(buf); + } + + /* + * Check that the versions match. In future this might accept + * several versions and set appropriate flags to handle them. + */ + if (sscanf(client_version_string, "SSH-%d.%d-%[^\n]\n", + &remote_major, &remote_minor, remote_version) != 3) { + s = "Protocol mismatch.\n"; + (void) atomicio(write, sock_out, s, strlen(s)); + close(sock_in); + close(sock_out); + log("Bad protocol version identification '%.100s' from %s", + client_version_string, get_remote_ipaddr()); + fatal_cleanup(); + } + debug("Client protocol version %d.%d; client software version %.100s", + remote_major, remote_minor, remote_version); + + switch(remote_major) { + case 1: + if (remote_minor < 3) { + packet_disconnect("Your ssh version is too old and" + "is no longer supported. Please install a newer version."); + } else if (remote_minor == 3) { + /* note that this disables agent-forwarding */ + enable_compat13(); + } + break; + default: + s = "Protocol major versions differ.\n"; + (void) atomicio(write, sock_out, s, strlen(s)); + close(sock_in); + close(sock_out); + log("Protocol major versions differ for %s: %d vs. %d", + get_remote_ipaddr(), PROTOCOL_MAJOR, remote_major); + fatal_cleanup(); + break; + } +} + /* * Main program for the daemon. */ @@ -325,12 +347,9 @@ main(int ac, char **av) extern int optind; int opt, sock_in = 0, sock_out = 0, newsock, i, fdsetsz, pid, on = 1; socklen_t fromlen; - int remote_major, remote_minor; int silentrsa = 0; fd_set *fdset; struct sockaddr_storage from; - char buf[100]; /* Must not be larger than remote_version. */ - char remote_version[100]; /* Must be at least as big as buf. */ const char *remote_ip; int remote_port; char *comment; @@ -794,73 +813,7 @@ main(int ac, char **av) if (!debug_flag) alarm(options.login_grace_time); - if (client_version_string != NULL) { - /* we are exec'ed by sshd2, so skip exchange of protocol version */ - strlcpy(buf, client_version_string, sizeof(buf)); - } else { - /* Send our protocol version identification. */ - snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", - PROTOCOL_MAJOR, PROTOCOL_MINOR, SSH_VERSION); - if (atomicio(write, sock_out, buf, strlen(buf)) != strlen(buf)) { - log("Could not write ident string to %s.", remote_ip); - fatal_cleanup(); - } - - /* Read other side\'s version identification. */ - for (i = 0; i < sizeof(buf) - 1; i++) { - if (read(sock_in, &buf[i], 1) != 1) { - log("Did not receive ident string from %s.", remote_ip); - fatal_cleanup(); - } - if (buf[i] == '\r') { - buf[i] = '\n'; - buf[i + 1] = 0; - break; - } - if (buf[i] == '\n') { - /* buf[i] == '\n' */ - buf[i + 1] = 0; - break; - } - } - buf[sizeof(buf) - 1] = 0; - } - - /* - * Check that the versions match. In future this might accept - * several versions and set appropriate flags to handle them. - */ - if (sscanf(buf, "SSH-%d.%d-%[^\n]\n", &remote_major, &remote_minor, - remote_version) != 3) { - char *s = "Protocol mismatch.\n"; - - (void) atomicio(write, sock_out, s, strlen(s)); - close(sock_in); - close(sock_out); - log("Bad protocol version identification '%.100s' from %s", - buf, remote_ip); - fatal_cleanup(); - } - debug("Client protocol version %d.%d; client software version %.100s", - remote_major, remote_minor, remote_version); - if (remote_major != PROTOCOL_MAJOR) { - char *s = "Protocol major versions differ.\n"; - - (void) atomicio(write, sock_out, s, strlen(s)); - close(sock_in); - close(sock_out); - log("Protocol major versions differ for %s: %d vs. %d", - remote_ip, PROTOCOL_MAJOR, remote_major); - fatal_cleanup(); - } - /* Check that the client has sufficiently high software version. */ - if (remote_major == 1 && remote_minor < 3) - packet_disconnect("Your ssh version is too old and is no longer supported. Please install a newer version."); - - if (remote_major == 1 && remote_minor == 3) { - /* note that this disables agent-forwarding */ - enable_compat13(); - } + sshd_exchange_identification(sock_in, sock_out); /* * Check that the connection comes from a privileged port. Rhosts- * and Rhosts-RSA-Authentication only make sense from priviledged @@ -884,8 +837,7 @@ main(int ac, char **av) packet_set_nonblocking(); /* perform the key exchange */ - do_ssh_kex(); - + do_ssh1_kex(); /* authenticate user and start session */ do_authentication(); @@ -895,10 +847,6 @@ main(int ac, char **av) (void) dest_tkt(); #endif /* KRB4 */ - /* Cleanup user's local Xauthority file. */ - if (xauthfile) - xauthfile_cleanup_proc(NULL); - /* The connection has been terminated. */ verbose("Closing connection to %.100s", remote_ip); @@ -914,7 +862,7 @@ main(int ac, char **av) * SSH1 key exchange */ void -do_ssh_kex() +do_ssh1_kex() { int i, len; int plen, slen; @@ -1101,1586 +1049,3 @@ do_ssh_kex() packet_send(); packet_write_wait(); } - - -/* - * Check if the user is allowed to log in via ssh. If user is listed in - * DenyUsers or user's primary group is listed in DenyGroups, false will - * be returned. If AllowUsers isn't empty and user isn't listed there, or - * if AllowGroups isn't empty and user isn't listed there, false will be - * returned. - * If the user's shell is not executable, false will be returned. - * Otherwise true is returned. - */ -static int -allowed_user(struct passwd * pw) -{ - struct stat st; - struct group *grp; - int i; -#ifdef WITH_AIXAUTHENTICATE - char *loginmsg; -#endif /* WITH_AIXAUTHENTICATE */ - - /* Shouldn't be called if pw is NULL, but better safe than sorry... */ - if (!pw) - return 0; - - /* deny if shell does not exists or is not executable */ - if (stat(pw->pw_shell, &st) != 0) - return 0; - if (!((st.st_mode & S_IFREG) && (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP)))) - return 0; - - /* Return false if user is listed in DenyUsers */ - if (options.num_deny_users > 0) { - if (!pw->pw_name) - return 0; - for (i = 0; i < options.num_deny_users; i++) - if (match_pattern(pw->pw_name, options.deny_users[i])) - return 0; - } - /* Return false if AllowUsers isn't empty and user isn't listed there */ - if (options.num_allow_users > 0) { - if (!pw->pw_name) - return 0; - for (i = 0; i < options.num_allow_users; i++) - if (match_pattern(pw->pw_name, options.allow_users[i])) - break; - /* i < options.num_allow_users iff we break for loop */ - if (i >= options.num_allow_users) - return 0; - } - /* Get the primary group name if we need it. Return false if it fails */ - if (options.num_deny_groups > 0 || options.num_allow_groups > 0) { - grp = getgrgid(pw->pw_gid); - if (!grp) - return 0; - - /* Return false if user's group is listed in DenyGroups */ - if (options.num_deny_groups > 0) { - if (!grp->gr_name) - return 0; - for (i = 0; i < options.num_deny_groups; i++) - if (match_pattern(grp->gr_name, options.deny_groups[i])) - return 0; - } - /* - * Return false if AllowGroups isn't empty and user's group - * isn't listed there - */ - if (options.num_allow_groups > 0) { - if (!grp->gr_name) - return 0; - for (i = 0; i < options.num_allow_groups; i++) - if (match_pattern(grp->gr_name, options.allow_groups[i])) - break; - /* i < options.num_allow_groups iff we break for - loop */ - if (i >= options.num_allow_groups) - return 0; - } - } - -#ifdef WITH_AIXAUTHENTICATE - if (loginrestrictions(pw->pw_name,S_LOGIN,NULL,&loginmsg) != 0) - return 0; -#endif /* WITH_AIXAUTHENTICATE */ - - /* We found no reason not to let this user try to log on... */ - return 1; -} - -/* - * Performs authentication of an incoming connection. Session key has already - * been exchanged and encryption is enabled. - */ -void -do_authentication() -{ - struct passwd *pw, pwcopy; - int plen; - unsigned int ulen; - char *user; - - /* Get the name of the user that we wish to log in as. */ - packet_read_expect(&plen, SSH_CMSG_USER); - - /* Get the user name. */ - user = packet_get_string(&ulen); - packet_integrity_check(plen, (4 + ulen), SSH_CMSG_USER); - - setproctitle("%s", user); - -#ifdef WITH_AIXAUTHENTICATE - char *loginmsg; -#endif /* WITH_AIXAUTHENTICATE */ - -#ifdef AFS - /* If machine has AFS, set process authentication group. */ - if (k_hasafs()) { - k_setpag(); - k_unlog(); - } -#endif /* AFS */ - - /* Verify that the user is a valid user. */ - pw = getpwnam(user); - if (!pw || !allowed_user(pw)) - do_fake_authloop(user); - xfree(user); - - /* Take a copy of the returned structure. */ - memset(&pwcopy, 0, sizeof(pwcopy)); - pwcopy.pw_name = xstrdup(pw->pw_name); - pwcopy.pw_passwd = xstrdup(pw->pw_passwd); - pwcopy.pw_uid = pw->pw_uid; - pwcopy.pw_gid = pw->pw_gid; - pwcopy.pw_dir = xstrdup(pw->pw_dir); - pwcopy.pw_shell = xstrdup(pw->pw_shell); - pw = &pwcopy; - -#ifdef USE_PAM - start_pam(pw); -#endif - - /* - * If we are not running as root, the user must have the same uid as - * the server. - */ - if (getuid() != 0 && pw->pw_uid != getuid()) - packet_disconnect("Cannot change user when server not running as root."); - - debug("Attempting authentication for %.100s.", pw->pw_name); - - /* If the user has no password, accept authentication immediately. */ - if (options.password_authentication && -#ifdef KRB4 - (!options.kerberos_authentication || options.kerberos_or_local_passwd) && -#endif /* KRB4 */ -#ifdef USE_PAM - auth_pam_password(pw, "")) { -#else /* USE_PAM */ - auth_password(pw, "")) { -#endif /* USE_PAM */ - /* Authentication with empty password succeeded. */ - log("Login for user %s from %.100s, accepted without authentication.", - pw->pw_name, get_remote_ipaddr()); - } else { - /* Loop until the user has been authenticated or the - connection is closed, do_authloop() returns only if - authentication is successfull */ - do_authloop(pw); - } - - /* The user has been authenticated and accepted. */ -#ifdef WITH_AIXAUTHENTICATE - loginsuccess(user,get_canonical_hostname(),"ssh",&loginmsg); -#endif /* WITH_AIXAUTHENTICATE */ - packet_start(SSH_SMSG_SUCCESS); - packet_send(); - packet_write_wait(); - - /* Perform session preparation. */ - do_authenticated(pw); -} - -#define AUTH_FAIL_MAX 6 -#define AUTH_FAIL_LOG (AUTH_FAIL_MAX/2) -#define AUTH_FAIL_MSG "Too many authentication failures for %.100s" - -/* - * read packets and try to authenticate local user *pw. - * return if authentication is successfull - */ -void -do_authloop(struct passwd * pw) -{ - int attempt = 0; - unsigned int bits; - RSA *client_host_key; - BIGNUM *n; - char *client_user = NULL, *password = NULL; - char user[1024]; - unsigned int dlen; - int plen, nlen, elen; - unsigned int ulen; - int type = 0; - void (*authlog) (const char *fmt,...) = verbose; - - /* Indicate that authentication is needed. */ - packet_start(SSH_SMSG_FAILURE); - packet_send(); - packet_write_wait(); - - for (attempt = 1;; attempt++) { - int authenticated = 0; - strlcpy(user, "", sizeof user); - - /* Get a packet from the client. */ - type = packet_read(&plen); - - /* Process the packet. */ - switch (type) { -#ifdef AFS - case SSH_CMSG_HAVE_KERBEROS_TGT: - if (!options.kerberos_tgt_passing) { - /* packet_get_all(); */ - verbose("Kerberos tgt passing disabled."); - break; - } else { - /* Accept Kerberos tgt. */ - char *tgt = packet_get_string(&dlen); - packet_integrity_check(plen, 4 + dlen, type); - if (!auth_kerberos_tgt(pw, tgt)) - verbose("Kerberos tgt REFUSED for %s", pw->pw_name); - xfree(tgt); - } - continue; - - case SSH_CMSG_HAVE_AFS_TOKEN: - if (!options.afs_token_passing || !k_hasafs()) { - /* packet_get_all(); */ - verbose("AFS token passing disabled."); - break; - } else { - /* Accept AFS token. */ - char *token_string = packet_get_string(&dlen); - packet_integrity_check(plen, 4 + dlen, type); - if (!auth_afs_token(pw, token_string)) - verbose("AFS token REFUSED for %s", pw->pw_name); - xfree(token_string); - } - continue; -#endif /* AFS */ -#ifdef KRB4 - case SSH_CMSG_AUTH_KERBEROS: - if (!options.kerberos_authentication) { - /* packet_get_all(); */ - verbose("Kerberos authentication disabled."); - break; - } else { - /* Try Kerberos v4 authentication. */ - KTEXT_ST auth; - char *tkt_user = NULL; - char *kdata = packet_get_string((unsigned int *) &auth.length); - packet_integrity_check(plen, 4 + auth.length, type); - - if (auth.length < MAX_KTXT_LEN) - memcpy(auth.dat, kdata, auth.length); - xfree(kdata); - - authenticated = auth_krb4(pw->pw_name, &auth, &tkt_user); - - if (authenticated) { - snprintf(user, sizeof user, " tktuser %s", tkt_user); - xfree(tkt_user); - } - } - break; -#endif /* KRB4 */ - - case SSH_CMSG_AUTH_RHOSTS: - if (!options.rhosts_authentication) { - verbose("Rhosts authentication disabled."); - break; - } - /* - * Get client user name. Note that we just have to - * trust the client; this is one reason why rhosts - * authentication is insecure. (Another is - * IP-spoofing on a local network.) - */ - client_user = packet_get_string(&ulen); - packet_integrity_check(plen, 4 + ulen, type); - - /* Try to authenticate using /etc/hosts.equiv and - .rhosts. */ - authenticated = auth_rhosts(pw, client_user); - - snprintf(user, sizeof user, " ruser %s", client_user); - break; - - case SSH_CMSG_AUTH_RHOSTS_RSA: - if (!options.rhosts_rsa_authentication) { - verbose("Rhosts with RSA authentication disabled."); - break; - } - /* - * Get client user name. Note that we just have to - * trust the client; root on the client machine can - * claim to be any user. - */ - client_user = packet_get_string(&ulen); - - /* Get the client host key. */ - client_host_key = RSA_new(); - if (client_host_key == NULL) - fatal("RSA_new failed"); - client_host_key->e = BN_new(); - client_host_key->n = BN_new(); - if (client_host_key->e == NULL || client_host_key->n == NULL) - fatal("BN_new failed"); - bits = packet_get_int(); - packet_get_bignum(client_host_key->e, &elen); - packet_get_bignum(client_host_key->n, &nlen); - - if (bits != BN_num_bits(client_host_key->n)) - error("Warning: keysize mismatch for client_host_key: " - "actual %d, announced %d", BN_num_bits(client_host_key->n), bits); - packet_integrity_check(plen, (4 + ulen) + 4 + elen + nlen, type); - - authenticated = auth_rhosts_rsa(pw, client_user, client_host_key); - RSA_free(client_host_key); - - snprintf(user, sizeof user, " ruser %s", client_user); - break; - - case SSH_CMSG_AUTH_RSA: - if (!options.rsa_authentication) { - verbose("RSA authentication disabled."); - break; - } - /* RSA authentication requested. */ - n = BN_new(); - packet_get_bignum(n, &nlen); - packet_integrity_check(plen, nlen, type); - authenticated = auth_rsa(pw, n); - BN_clear_free(n); - break; - - case SSH_CMSG_AUTH_PASSWORD: - if (!options.password_authentication) { - verbose("Password authentication disabled."); - break; - } - /* - * Read user password. It is in plain text, but was - * transmitted over the encrypted channel so it is - * not visible to an outside observer. - */ - password = packet_get_string(&dlen); - packet_integrity_check(plen, 4 + dlen, type); - -#ifdef USE_PAM - /* Do PAM auth with password */ - authenticated = auth_pam_password(pw, password); -#else /* USE_PAM */ - /* Try authentication with the password. */ - authenticated = auth_password(pw, password); -#endif /* USE_PAM */ - memset(password, 0, strlen(password)); - xfree(password); - break; - -#ifdef SKEY - case SSH_CMSG_AUTH_TIS: - debug("rcvd SSH_CMSG_AUTH_TIS"); - if (options.skey_authentication == 1) { - char *skeyinfo = skey_keyinfo(pw->pw_name); - if (skeyinfo == NULL) { - debug("generating fake skeyinfo for %.100s.", pw->pw_name); - skeyinfo = skey_fake_keyinfo(pw->pw_name); - } - if (skeyinfo != NULL) { - /* we send our s/key- in tis-challenge messages */ - debug("sending challenge '%s'", skeyinfo); - packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE); - packet_put_string(skeyinfo, strlen(skeyinfo)); - packet_send(); - packet_write_wait(); - continue; - } - } - break; - case SSH_CMSG_AUTH_TIS_RESPONSE: - debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE"); - if (options.skey_authentication == 1) { - char *response = packet_get_string(&dlen); - debug("skey response == '%s'", response); - packet_integrity_check(plen, 4 + dlen, type); - authenticated = (skey_haskey(pw->pw_name) == 0 && - skey_passcheck(pw->pw_name, response) != -1); - xfree(response); - } - break; -#else - case SSH_CMSG_AUTH_TIS: - /* TIS Authentication is unsupported */ - log("TIS authentication unsupported."); - break; -#endif - - default: - /* - * Any unknown messages will be ignored (and failure - * returned) during authentication. - */ - log("Unknown message during authentication: type %d", type); - break; - } - - /* - * Check if the user is logging in as root and root logins - * are disallowed. - * Note that root login is allowed for forced commands. - */ - if (authenticated && pw->pw_uid == 0 && !options.permit_root_login) { - if (forced_command) { - log("Root login accepted for forced command."); - } else { - authenticated = 0; - log("ROOT LOGIN REFUSED FROM %.200s", - get_canonical_hostname()); - } - } - - /* Raise logging level */ - if (authenticated || - attempt == AUTH_FAIL_LOG || - type == SSH_CMSG_AUTH_PASSWORD) - authlog = log; - - authlog("%s %s for %.200s from %.200s port %d%s", - authenticated ? "Accepted" : "Failed", - get_authname(type), - pw->pw_uid == 0 ? "ROOT" : pw->pw_name, - get_remote_ipaddr(), - get_remote_port(), - user); - -#ifdef USE_PAM - if (authenticated) { - if (!do_pam_account(pw->pw_name, client_user)) { - if (client_user != NULL) { - xfree(client_user); - client_user = NULL; - } - do_fake_authloop(pw->pw_name); - } - return; - } -#else /* USE_PAM */ - if (authenticated) { - return; - } -#endif /* USE_PAM */ - - if (client_user != NULL) { - xfree(client_user); - client_user = NULL; - } - - if (attempt > AUTH_FAIL_MAX) - packet_disconnect(AUTH_FAIL_MSG, pw->pw_name); - - /* Send a message indicating that the authentication attempt failed. */ - packet_start(SSH_SMSG_FAILURE); - packet_send(); - packet_write_wait(); - } -} - -/* - * The user does not exist or access is denied, - * but fake indication that authentication is needed. - */ -void -do_fake_authloop(char *user) -{ - int attempt = 0; - - log("Faking authloop for illegal user %.200s from %.200s port %d", - user, - get_remote_ipaddr(), - get_remote_port()); - - /* Indicate that authentication is needed. */ - packet_start(SSH_SMSG_FAILURE); - packet_send(); - packet_write_wait(); - - /* - * Keep reading packets, and always respond with a failure. This is - * to avoid disclosing whether such a user really exists. - */ - for (attempt = 1;; attempt++) { - /* Read a packet. This will not return if the client disconnects. */ - int plen; -#ifndef SKEY - (void)packet_read(&plen); -#else /* SKEY */ - int type = packet_read(&plen); - unsigned int dlen; - char *password, *skeyinfo; - /* Try to send a fake s/key challenge. */ - if (options.skey_authentication == 1 && - (skeyinfo = skey_fake_keyinfo(user)) != NULL) { - password = NULL; - if (type == SSH_CMSG_AUTH_TIS) { - packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE); - packet_put_string(skeyinfo, strlen(skeyinfo)); - packet_send(); - packet_write_wait(); - continue; - } else if (type == SSH_CMSG_AUTH_PASSWORD && - options.password_authentication && - (password = packet_get_string(&dlen)) != NULL && - dlen == 5 && - strncasecmp(password, "s/key", 5) == 0 ) { - packet_send_debug(skeyinfo); - } - if (password != NULL) - xfree(password); - } -#endif - if (attempt > AUTH_FAIL_MAX) - packet_disconnect(AUTH_FAIL_MSG, user); - - /* - * Send failure. This should be indistinguishable from a - * failed authentication. - */ - packet_start(SSH_SMSG_FAILURE); - packet_send(); - packet_write_wait(); -#ifdef WITH_AIXAUTHENTICATE - if (strncmp(get_authname(type),"password", - strlen(get_authname(type))) == 0) - loginfailed(pw->pw_name,get_canonical_hostname(),"ssh"); -#endif /* WITH_AIXAUTHENTICATE */ - } - /* NOTREACHED */ - abort(); -} - -struct pty_cleanup_context { - const char *ttyname; - int pid; -}; - -/* - * Function to perform cleanup if we get aborted abnormally (e.g., due to a - * dropped connection). - */ -void -pty_cleanup_proc(void *context) -{ - struct pty_cleanup_context *cu = context; - - debug("pty_cleanup_proc called"); - - /* Record that the user has logged out. */ - record_logout(cu->pid, cu->ttyname); - - /* Release the pseudo-tty. */ - pty_release(cu->ttyname); -} - -/* simple cleanup: chown tty slave back to root */ -static void -pty_release_proc(void *tty) -{ - char *ttyname = tty; - pty_release(ttyname); -} - -/* - * Prepares for an interactive session. This is called after the user has - * been successfully authenticated. During this message exchange, pseudo - * terminals are allocated, X11, TCP/IP, and authentication agent forwardings - * are requested, etc. - */ -void -do_authenticated(struct passwd * pw) -{ - int type; - int compression_level = 0, enable_compression_after_reply = 0; - int have_pty = 0, ptyfd = -1, ttyfd = -1; - int row, col, xpixel, ypixel, screen; - char ttyname[64]; - char *command, *term = NULL, *display = NULL, *proto = NULL, *data = NULL; - int plen; - unsigned int dlen; - int n_bytes; - - /* - * Cancel the alarm we set to limit the time taken for - * authentication. - */ - alarm(0); - - /* - * Inform the channel mechanism that we are the server side and that - * the client may request to connect to any port at all. (The user - * could do it anyway, and we wouldn\'t know what is permitted except - * by the client telling us, so we can equally well trust the client - * not to request anything bogus.) - */ - if (!no_port_forwarding_flag) - channel_permit_all_opens(); - - /* - * We stay in this loop until the client requests to execute a shell - * or a command. - */ - while (1) { - - /* Get a packet from the client. */ - type = packet_read(&plen); - - /* Process the packet. */ - switch (type) { - case SSH_CMSG_REQUEST_COMPRESSION: - packet_integrity_check(plen, 4, type); - compression_level = packet_get_int(); - if (compression_level < 1 || compression_level > 9) { - packet_send_debug("Received illegal compression level %d.", - compression_level); - goto fail; - } - /* Enable compression after we have responded with SUCCESS. */ - enable_compression_after_reply = 1; - break; - - case SSH_CMSG_REQUEST_PTY: - if (no_pty_flag) { - debug("Allocating a pty not permitted for this authentication."); - goto fail; - } - if (have_pty) - packet_disconnect("Protocol error: you already have a pty."); - - debug("Allocating pty."); - - /* Allocate a pty and open it. */ - if (!pty_allocate(&ptyfd, &ttyfd, ttyname, - sizeof(ttyname))) { - error("Failed to allocate pty."); - goto fail; - } - fatal_add_cleanup(pty_release_proc, (void *)ttyname); - pty_setowner(pw, ttyname); - - /* Get TERM from the packet. Note that the value may be of arbitrary length. */ - term = packet_get_string(&dlen); - packet_integrity_check(dlen, strlen(term), type); - - /* Remaining bytes */ - n_bytes = plen - (4 + dlen + 4 * 4); - - if (strcmp(term, "") == 0) { - xfree(term); - term = NULL; - } - - /* Get window size from the packet. */ - row = packet_get_int(); - col = packet_get_int(); - xpixel = packet_get_int(); - ypixel = packet_get_int(); - pty_change_window_size(ptyfd, row, col, xpixel, ypixel); - - /* Get tty modes from the packet. */ - tty_parse_modes(ttyfd, &n_bytes); - packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type); - - /* Indicate that we now have a pty. */ - have_pty = 1; - break; - - case SSH_CMSG_X11_REQUEST_FORWARDING: - if (!options.x11_forwarding) { - packet_send_debug("X11 forwarding disabled in server configuration file."); - goto fail; - } -#ifdef XAUTH_PATH - if (no_x11_forwarding_flag) { - packet_send_debug("X11 forwarding not permitted for this authentication."); - goto fail; - } - debug("Received request for X11 forwarding with auth spoofing."); - if (display) - packet_disconnect("Protocol error: X11 display already set."); - { - unsigned int proto_len, data_len; - proto = packet_get_string(&proto_len); - data = packet_get_string(&data_len); - packet_integrity_check(plen, 4 + proto_len + 4 + data_len + 4, type); - } - if (packet_get_protocol_flags() & SSH_PROTOFLAG_SCREEN_NUMBER) - screen = packet_get_int(); - else - screen = 0; - display = x11_create_display_inet(screen, options.x11_display_offset); - if (!display) - goto fail; - - /* Setup to always have a local .Xauthority. */ - xauthfile = xmalloc(MAXPATHLEN); - strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN); - temporarily_use_uid(pw->pw_uid); - if (mkdtemp(xauthfile) == NULL) { - restore_uid(); - error("private X11 dir: mkdtemp %s failed: %s", - xauthfile, strerror(errno)); - xfree(xauthfile); - xauthfile = NULL; - goto fail; - } - strlcat(xauthfile, "/cookies", MAXPATHLEN); - open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600); - restore_uid(); - fatal_add_cleanup(xauthfile_cleanup_proc, NULL); - break; -#else /* XAUTH_PATH */ - packet_send_debug("No xauth program; cannot forward with spoofing."); - goto fail; -#endif /* XAUTH_PATH */ - - case SSH_CMSG_AGENT_REQUEST_FORWARDING: - if (no_agent_forwarding_flag || compat13) { - debug("Authentication agent forwarding not permitted for this authentication."); - goto fail; - } - debug("Received authentication agent forwarding request."); - auth_input_request_forwarding(pw); - break; - - case SSH_CMSG_PORT_FORWARD_REQUEST: - if (no_port_forwarding_flag) { - debug("Port forwarding not permitted for this authentication."); - goto fail; - } - debug("Received TCP/IP port forwarding request."); - channel_input_port_forward_request(pw->pw_uid == 0); - break; - - case SSH_CMSG_MAX_PACKET_SIZE: - if (packet_set_maxsize(packet_get_int()) < 0) - goto fail; - break; - - case SSH_CMSG_EXEC_SHELL: - /* Set interactive/non-interactive mode. */ - packet_set_interactive(have_pty || display != NULL, - options.keepalives); - - if (forced_command != NULL) - goto do_forced_command; - debug("Forking shell."); - packet_integrity_check(plen, 0, type); - if (have_pty) - do_exec_pty(NULL, ptyfd, ttyfd, ttyname, pw, term, display, proto, data); - else - do_exec_no_pty(NULL, pw, display, proto, data); - return; - - case SSH_CMSG_EXEC_CMD: - /* Set interactive/non-interactive mode. */ - packet_set_interactive(have_pty || display != NULL, - options.keepalives); - - if (forced_command != NULL) - goto do_forced_command; - /* Get command from the packet. */ - { - unsigned int dlen; - command = packet_get_string(&dlen); - debug("Executing command '%.500s'", command); - packet_integrity_check(plen, 4 + dlen, type); - } - if (have_pty) - do_exec_pty(command, ptyfd, ttyfd, ttyname, pw, term, display, proto, data); - else - do_exec_no_pty(command, pw, display, proto, data); - xfree(command); - return; - - default: - /* - * Any unknown messages in this phase are ignored, - * and a failure message is returned. - */ - log("Unknown packet type received after authentication: %d", type); - goto fail; - } - - /* The request was successfully processed. */ - packet_start(SSH_SMSG_SUCCESS); - packet_send(); - packet_write_wait(); - - /* Enable compression now that we have replied if appropriate. */ - if (enable_compression_after_reply) { - enable_compression_after_reply = 0; - packet_start_compression(compression_level); - } - continue; - -fail: - /* The request failed. */ - packet_start(SSH_SMSG_FAILURE); - packet_send(); - packet_write_wait(); - continue; - -do_forced_command: - /* - * There is a forced command specified for this login. - * Execute it. - */ - debug("Executing forced command: %.900s", forced_command); - if (have_pty) - do_exec_pty(forced_command, ptyfd, ttyfd, ttyname, pw, term, display, proto, data); - else - do_exec_no_pty(forced_command, pw, display, proto, data); - return; - } -} - -/* - * This is called to fork and execute a command when we have no tty. This - * will call do_child from the child, and server_loop from the parent after - * setting up file descriptors and such. - */ -void -do_exec_no_pty(const char *command, struct passwd * pw, - const char *display, const char *auth_proto, - const char *auth_data) -{ - int pid; - -#ifdef USE_PIPES - int pin[2], pout[2], perr[2]; - /* Allocate pipes for communicating with the program. */ - if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0) - packet_disconnect("Could not create pipes: %.100s", - strerror(errno)); -#else /* USE_PIPES */ - int inout[2], err[2]; - /* Uses socket pairs to communicate with the program. */ - if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 || - socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) - packet_disconnect("Could not create socket pairs: %.100s", - strerror(errno)); -#endif /* USE_PIPES */ - - setproctitle("%s@notty", pw->pw_name); - -#ifdef USE_PAM - do_pam_setcred(); -#endif /* USE_PAM */ - - /* Fork the child. */ - if ((pid = fork()) == 0) { - /* Child. Reinitialize the log since the pid has changed. */ - log_init(av0, options.log_level, options.log_facility, log_stderr); - - /* - * Create a new session and process group since the 4.4BSD - * setlogin() affects the entire process group. - */ - if (setsid() < 0) - error("setsid failed: %.100s", strerror(errno)); - -#ifdef USE_PIPES - /* - * Redirect stdin. We close the parent side of the socket - * pair, and make the child side the standard input. - */ - close(pin[1]); - if (dup2(pin[0], 0) < 0) - perror("dup2 stdin"); - close(pin[0]); - - /* Redirect stdout. */ - close(pout[0]); - if (dup2(pout[1], 1) < 0) - perror("dup2 stdout"); - close(pout[1]); - - /* Redirect stderr. */ - close(perr[0]); - if (dup2(perr[1], 2) < 0) - perror("dup2 stderr"); - close(perr[1]); -#else /* USE_PIPES */ - /* - * Redirect stdin, stdout, and stderr. Stdin and stdout will - * use the same socket, as some programs (particularly rdist) - * seem to depend on it. - */ - close(inout[1]); - close(err[1]); - if (dup2(inout[0], 0) < 0) /* stdin */ - perror("dup2 stdin"); - if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */ - perror("dup2 stdout"); - if (dup2(err[0], 2) < 0) /* stderr */ - perror("dup2 stderr"); -#endif /* USE_PIPES */ - - /* Do processing for the child (exec command etc). */ - do_child(command, pw, NULL, display, auth_proto, auth_data, NULL); - /* NOTREACHED */ - } - if (pid < 0) - packet_disconnect("fork failed: %.100s", strerror(errno)); -#ifdef USE_PIPES - /* We are the parent. Close the child sides of the pipes. */ - close(pin[0]); - close(pout[1]); - close(perr[1]); - - /* Enter the interactive session. */ - server_loop(pid, pin[1], pout[0], perr[0]); - /* server_loop has closed pin[1], pout[1], and perr[1]. */ -#else /* USE_PIPES */ - /* We are the parent. Close the child sides of the socket pairs. */ - close(inout[0]); - close(err[0]); - - /* - * Enter the interactive session. Note: server_loop must be able to - * handle the case that fdin and fdout are the same. - */ - server_loop(pid, inout[1], inout[1], err[1]); - /* server_loop has closed inout[1] and err[1]. */ -#endif /* USE_PIPES */ -} - -/* - * This is called to fork and execute a command when we have a tty. This - * will call do_child from the child, and server_loop from the parent after - * setting up file descriptors, controlling tty, updating wtmp, utmp, - * lastlog, and other such operations. - */ -void -do_exec_pty(const char *command, int ptyfd, int ttyfd, - const char *ttyname, struct passwd * pw, const char *term, - const char *display, const char *auth_proto, - const char *auth_data) -{ - int pid, fdout; - int ptymaster; - const char *hostname; - time_t last_login_time; - char buf[100], *time_string; - FILE *f; - char line[256]; - struct stat st; - int quiet_login; - struct sockaddr_storage from; - socklen_t fromlen; - struct pty_cleanup_context cleanup_context; - - /* Get remote host name. */ - hostname = get_canonical_hostname(); - - /* - * Get the time when the user last logged in. Buf will be set to - * contain the hostname the last login was from. - */ - if (!options.use_login) { - last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name, - buf, sizeof(buf)); - } - setproctitle("%s@%s", pw->pw_name, strrchr(ttyname, '/') + 1); - -#ifdef USE_PAM - do_pam_session(pw->pw_name, ttyname); - do_pam_setcred(); -#endif /* USE_PAM */ - - /* Fork the child. */ - if ((pid = fork()) == 0) { - pid = getpid(); - - /* Child. Reinitialize the log because the pid has - changed. */ - log_init(av0, options.log_level, options.log_facility, log_stderr); - - /* Close the master side of the pseudo tty. */ - close(ptyfd); - - /* Make the pseudo tty our controlling tty. */ - pty_make_controlling_tty(&ttyfd, ttyname); - - /* Redirect stdin from the pseudo tty. */ - if (dup2(ttyfd, fileno(stdin)) < 0) - error("dup2 stdin failed: %.100s", strerror(errno)); - - /* Redirect stdout to the pseudo tty. */ - if (dup2(ttyfd, fileno(stdout)) < 0) - error("dup2 stdin failed: %.100s", strerror(errno)); - - /* Redirect stderr to the pseudo tty. */ - if (dup2(ttyfd, fileno(stderr)) < 0) - error("dup2 stdin failed: %.100s", strerror(errno)); - - /* Close the extra descriptor for the pseudo tty. */ - close(ttyfd); - - /* - * Get IP address of client. This is needed because we want - * to record where the user logged in from. If the - * connection is not a socket, let the ip address be 0.0.0.0. - */ - memset(&from, 0, sizeof(from)); - if (packet_get_connection_in() == packet_get_connection_out()) { - fromlen = sizeof(from); - if (getpeername(packet_get_connection_in(), - (struct sockaddr *) & from, &fromlen) < 0) { - debug("getpeername: %.100s", strerror(errno)); - fatal_cleanup(); - } - } - /* Record that there was a login on that terminal. */ - record_login(pid, ttyname, pw->pw_name, pw->pw_uid, hostname, - (struct sockaddr *)&from); - - /* Check if .hushlogin exists. */ - snprintf(line, sizeof line, "%.200s/.hushlogin", pw->pw_dir); - quiet_login = stat(line, &st) >= 0; - -#ifdef USE_PAM - if (!quiet_login) - print_pam_messages(); -#endif /* USE_PAM */ - - /* - * If the user has logged in before, display the time of last - * login. However, don't display anything extra if a command - * has been specified (so that ssh can be used to execute - * commands on a remote machine without users knowing they - * are going to another machine). Login(1) will do this for - * us as well, so check if login(1) is used - */ - if (command == NULL && last_login_time != 0 && !quiet_login && - !options.use_login) { - /* Convert the date to a string. */ - time_string = ctime(&last_login_time); - /* Remove the trailing newline. */ - if (strchr(time_string, '\n')) - *strchr(time_string, '\n') = 0; - /* Display the last login time. Host if displayed - if known. */ - if (strcmp(buf, "") == 0) - printf("Last login: %s\r\n", time_string); - else - printf("Last login: %s from %s\r\n", time_string, buf); - } - /* - * Print /etc/motd unless a command was specified or printing - * it was disabled in server options or login(1) will be - * used. Note that some machines appear to print it in - * /etc/profile or similar. - */ - if (command == NULL && options.print_motd && !quiet_login && - !options.use_login) { - /* Print /etc/motd if it exists. */ - f = fopen("/etc/motd", "r"); - if (f) { - while (fgets(line, sizeof(line), f)) - fputs(line, stdout); - fclose(f); - } - } - /* Do common processing for the child, such as execing the command. */ - do_child(command, pw, term, display, auth_proto, auth_data, ttyname); - /* NOTREACHED */ - } - if (pid < 0) - packet_disconnect("fork failed: %.100s", strerror(errno)); - /* Parent. Close the slave side of the pseudo tty. */ - close(ttyfd); - - /* - * Add a cleanup function to clear the utmp entry and record logout - * time in case we call fatal() (e.g., the connection gets closed). - */ - cleanup_context.pid = pid; - cleanup_context.ttyname = ttyname; - fatal_add_cleanup(pty_cleanup_proc, (void *) &cleanup_context); - fatal_remove_cleanup(pty_release_proc, (void *) ttyname); - - /* - * Create another descriptor of the pty master side for use as the - * standard input. We could use the original descriptor, but this - * simplifies code in server_loop. The descriptor is bidirectional. - */ - fdout = dup(ptyfd); - if (fdout < 0) - packet_disconnect("dup #1 failed: %.100s", strerror(errno)); - - /* we keep a reference to the pty master */ - ptymaster = dup(ptyfd); - if (ptymaster < 0) - packet_disconnect("dup #2 failed: %.100s", strerror(errno)); - - /* Enter interactive session. */ - server_loop(pid, ptyfd, fdout, -1); - /* server_loop _has_ closed ptyfd and fdout. */ - - /* Cancel the cleanup function. */ - fatal_remove_cleanup(pty_cleanup_proc, (void *) &cleanup_context); - - /* Record that the user has logged out. */ - record_logout(pid, ttyname); - - /* Release the pseudo-tty. */ - pty_release(ttyname); - - /* - * Close the server side of the socket pairs. We must do this after - * the pty cleanup, so that another process doesn't get this pty - * while we're still cleaning up. - */ - if (close(ptymaster) < 0) - error("close(ptymaster): %s", strerror(errno)); -} - -/* - * Sets the value of the given variable in the environment. If the variable - * already exists, its value is overriden. - */ -void -child_set_env(char ***envp, unsigned int *envsizep, const char *name, - const char *value) -{ - unsigned int i, namelen; - char **env; - - /* - * Find the slot where the value should be stored. If the variable - * already exists, we reuse the slot; otherwise we append a new slot - * at the end of the array, expanding if necessary. - */ - env = *envp; - namelen = strlen(name); - for (i = 0; env[i]; i++) - if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') - break; - if (env[i]) { - /* Reuse the slot. */ - xfree(env[i]); - } else { - /* New variable. Expand if necessary. */ - if (i >= (*envsizep) - 1) { - (*envsizep) += 50; - env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *)); - } - /* Need to set the NULL pointer at end of array beyond the new slot. */ - env[i + 1] = NULL; - } - - /* Allocate space and format the variable in the appropriate slot. */ - env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); - snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); -} - -/* - * Reads environment variables from the given file and adds/overrides them - * into the environment. If the file does not exist, this does nothing. - * Otherwise, it must consist of empty lines, comments (line starts with '#') - * and assignments of the form name=value. No other forms are allowed. - */ -void -read_environment_file(char ***env, unsigned int *envsize, - const char *filename) -{ - FILE *f; - char buf[4096]; - char *cp, *value; - - f = fopen(filename, "r"); - if (!f) - return; - - while (fgets(buf, sizeof(buf), f)) { - for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) - ; - if (!*cp || *cp == '#' || *cp == '\n') - continue; - if (strchr(cp, '\n')) - *strchr(cp, '\n') = '\0'; - value = strchr(cp, '='); - if (value == NULL) { - fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf); - continue; - } - /* Replace the equals sign by nul, and advance value to the value string. */ - *value = '\0'; - value++; - child_set_env(env, envsize, cp, value); - } - fclose(f); -} - -#ifdef USE_PAM -/* - * Sets any environment variables which have been specified by PAM - */ -void do_pam_environment(char ***env, int *envsize) -{ - char *equals, var_name[512], var_val[512]; - char **pam_env; - int i; - - if ((pam_env = fetch_pam_environment()) == NULL) - return; - - for(i = 0; pam_env[i] != NULL; i++) { - if ((equals = strstr(pam_env[i], "=")) == NULL) - continue; - - if (strlen(pam_env[i]) < (sizeof(var_name) - 1)) - { - memset(var_name, '\0', sizeof(var_name)); - memset(var_val, '\0', sizeof(var_val)); - - strncpy(var_name, pam_env[i], equals - pam_env[i]); - strcpy(var_val, equals + 1); - - debug("PAM environment: %s=%s", var_name, var_val); - - child_set_env(env, envsize, var_name, var_val); - } - } -} -#endif /* USE_PAM */ - -/* - * Performs common processing for the child, such as setting up the - * environment, closing extra file descriptors, setting the user and group - * ids, and executing the command or shell. - */ -void -do_child(const char *command, struct passwd * pw, const char *term, - const char *display, const char *auth_proto, - const char *auth_data, const char *ttyname) -{ - const char *shell, *cp = NULL; - char buf[256]; - FILE *f; - unsigned int envsize, i; - char **env; - extern char **environ; - struct stat st; - char *argv[10]; - -#ifndef USE_PAM /* pam_nologin handles this */ - /* Check /etc/nologin. */ - f = fopen("/etc/nologin", "r"); - if (f) { - /* /etc/nologin exists. Print its contents and exit. */ - while (fgets(buf, sizeof(buf), f)) - fputs(buf, stderr); - fclose(f); - if (pw->pw_uid != 0) - exit(254); - } -#endif /* USE_PAM */ - - /* Set login name in the kernel. */ - if (setlogin(pw->pw_name) < 0) - error("setlogin failed: %s", strerror(errno)); - - /* Set uid, gid, and groups. */ - /* Login(1) does this as well, and it needs uid 0 for the "-h" - switch, so we let login(1) to this for us. */ - if (!options.use_login) { - if (getuid() == 0 || geteuid() == 0) { - if (setgid(pw->pw_gid) < 0) { - perror("setgid"); - exit(1); - } - /* Initialize the group list. */ - if (initgroups(pw->pw_name, pw->pw_gid) < 0) { - perror("initgroups"); - exit(1); - } - endgrent(); - - /* Permanently switch to the desired uid. */ - permanently_set_uid(pw->pw_uid); - } - if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) - fatal("Failed to set uids to %d.", (int) pw->pw_uid); - } - /* - * Get the shell from the password data. An empty shell field is - * legal, and means /bin/sh. - */ - shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; - -#ifdef AFS - /* Try to get AFS tokens for the local cell. */ - if (k_hasafs()) { - char cell[64]; - - if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) - krb_afslog(cell, 0); - - krb_afslog(0, 0); - } -#endif /* AFS */ - - /* Initialize the environment. */ - envsize = 100; - env = xmalloc(envsize * sizeof(char *)); - env[0] = NULL; - - if (!options.use_login) { - /* Set basic environment. */ - child_set_env(&env, &envsize, "USER", pw->pw_name); - child_set_env(&env, &envsize, "LOGNAME", pw->pw_name); - child_set_env(&env, &envsize, "HOME", pw->pw_dir); - child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); - - snprintf(buf, sizeof buf, "%.200s/%.50s", - _PATH_MAILDIR, pw->pw_name); - child_set_env(&env, &envsize, "MAIL", buf); - - /* Normal systems set SHELL by default. */ - child_set_env(&env, &envsize, "SHELL", shell); - } - if (getenv("TZ")) - child_set_env(&env, &envsize, "TZ", getenv("TZ")); - - /* Set custom environment options from RSA authentication. */ - while (custom_environment) { - struct envstring *ce = custom_environment; - char *s = ce->s; - int i; - for (i = 0; s[i] != '=' && s[i]; i++); - if (s[i] == '=') { - s[i] = 0; - child_set_env(&env, &envsize, s, s + i + 1); - } - custom_environment = ce->next; - xfree(ce->s); - xfree(ce); - } - - snprintf(buf, sizeof buf, "%.50s %d %d", - get_remote_ipaddr(), get_remote_port(), get_local_port()); - child_set_env(&env, &envsize, "SSH_CLIENT", buf); - - if (ttyname) - child_set_env(&env, &envsize, "SSH_TTY", ttyname); - if (term) - child_set_env(&env, &envsize, "TERM", term); - if (display) - child_set_env(&env, &envsize, "DISPLAY", display); - -#ifdef _AIX - { - char *authstate,*krb5cc; - - if ((authstate = getenv("AUTHSTATE")) != NULL) - child_set_env(&env,&envsize,"AUTHSTATE",authstate); - - if ((krb5cc = getenv("KRB5CCNAME")) != NULL) - child_set_env(&env,&envsize,"KRB5CCNAME",krb5cc); - } -#endif - -#ifdef KRB4 - { - extern char *ticket; - - if (ticket) - child_set_env(&env, &envsize, "KRBTKFILE", ticket); - } -#endif /* KRB4 */ - -#ifdef USE_PAM - /* Pull in any environment variables that may have been set by PAM. */ - do_pam_environment(&env, &envsize); -#endif /* USE_PAM */ - - if (xauthfile) - child_set_env(&env, &envsize, "XAUTHORITY", xauthfile); - - if (auth_get_socket_name() != NULL) - child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, - auth_get_socket_name()); - - read_environment_file(&env,&envsize,"/etc/environment"); - - /* read $HOME/.ssh/environment. */ - if (!options.use_login) { - snprintf(buf, sizeof buf, "%.200s/.ssh/environment", pw->pw_dir); - read_environment_file(&env, &envsize, buf); - } - if (debug_flag) { - /* dump the environment */ - fprintf(stderr, "Environment:\n"); - for (i = 0; env[i]; i++) - fprintf(stderr, " %.200s\n", env[i]); - } - /* - * Close the connection descriptors; note that this is the child, and - * the server will still have the socket open, and it is important - * that we do not shutdown it. Note that the descriptors cannot be - * closed before building the environment, as we call - * get_remote_ipaddr there. - */ - if (packet_get_connection_in() == packet_get_connection_out()) - close(packet_get_connection_in()); - else { - close(packet_get_connection_in()); - close(packet_get_connection_out()); - } - /* - * Close all descriptors related to channels. They will still remain - * open in the parent. - */ - /* XXX better use close-on-exec? -markus */ - channel_close_all(); - - /* - * Close any extra file descriptors. Note that there may still be - * descriptors left by system functions. They will be closed later. - */ - endpwent(); - - /* - * Close any extra open file descriptors so that we don\'t have them - * hanging around in clients. Note that we want to do this after - * initgroups, because at least on Solaris 2.3 it leaves file - * descriptors open. - */ - for (i = 3; i < 64; i++) - close(i); - - /* Change current directory to the user\'s home directory. */ - if (chdir(pw->pw_dir) < 0) - fprintf(stderr, "Could not chdir to home directory %s: %s\n", - pw->pw_dir, strerror(errno)); - - /* - * Must take new environment into use so that .ssh/rc, /etc/sshrc and - * xauth are run in the proper environment. - */ - environ = env; - - /* - * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first - * in this order). - */ - if (!options.use_login) { - if (stat(SSH_USER_RC, &st) >= 0) { - if (debug_flag) - fprintf(stderr, "Running /bin/sh %s\n", SSH_USER_RC); - - f = popen("/bin/sh " SSH_USER_RC, "w"); - if (f) { - if (auth_proto != NULL && auth_data != NULL) - fprintf(f, "%s %s\n", auth_proto, auth_data); - pclose(f); - } else - fprintf(stderr, "Could not run %s\n", SSH_USER_RC); - } else if (stat(SSH_SYSTEM_RC, &st) >= 0) { - if (debug_flag) - fprintf(stderr, "Running /bin/sh %s\n", SSH_SYSTEM_RC); - - f = popen("/bin/sh " SSH_SYSTEM_RC, "w"); - if (f) { - if (auth_proto != NULL && auth_data != NULL) - fprintf(f, "%s %s\n", auth_proto, auth_data); - pclose(f); - } else - fprintf(stderr, "Could not run %s\n", SSH_SYSTEM_RC); - } -#ifdef XAUTH_PATH - else { - /* Add authority data to .Xauthority if appropriate. */ - if (auth_proto != NULL && auth_data != NULL) { - if (debug_flag) - fprintf(stderr, "Running %.100s add %.100s %.100s %.100s\n", - XAUTH_PATH, display, auth_proto, auth_data); - - f = popen(XAUTH_PATH " -q -", "w"); - if (f) { - fprintf(f, "add %s %s %s\n", display, auth_proto, auth_data); - pclose(f); - } else - fprintf(stderr, "Could not run %s -q -\n", XAUTH_PATH); - } - } -#endif /* XAUTH_PATH */ - - /* Get the last component of the shell name. */ - cp = strrchr(shell, '/'); - if (cp) - cp++; - else - cp = shell; - } - /* - * If we have no command, execute the shell. In this case, the shell - * name to be passed in argv[0] is preceded by '-' to indicate that - * this is a login shell. - */ - if (!command) { - if (!options.use_login) { - char buf[256]; - - /* - * Check for mail if we have a tty and it was enabled - * in server options. - */ - if (ttyname && options.check_mail) { - char *mailbox; - struct stat mailstat; - mailbox = getenv("MAIL"); - if (mailbox != NULL) { - if (stat(mailbox, &mailstat) != 0 || mailstat.st_size == 0) - printf("No mail.\n"); - else if (mailstat.st_mtime < mailstat.st_atime) - printf("You have mail.\n"); - else - printf("You have new mail.\n"); - } - } - /* Start the shell. Set initial character to '-'. */ - buf[0] = '-'; - strncpy(buf + 1, cp, sizeof(buf) - 1); - buf[sizeof(buf) - 1] = 0; - - /* Execute the shell. */ - argv[0] = buf; - argv[1] = NULL; - execve(shell, argv, env); - - /* Executing the shell failed. */ - perror(shell); - exit(1); - - } else { - /* Launch login(1). */ - - execl(LOGIN_PROGRAM, "login", "-h", get_remote_ipaddr(), - "-p", "-f", "--", pw->pw_name, NULL); - - /* Login couldn't be executed, die. */ - - perror("login"); - exit(1); - } - } - /* - * Execute the command using the user's shell. This uses the -c - * option to execute the command. - */ - argv[0] = (char *) cp; - argv[1] = "-c"; - argv[2] = (char *) command; - argv[3] = NULL; - execve(shell, argv, env); - perror(shell); - exit(1); -} |