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author | Damien Miller <djm@mindrot.org> | 2014-02-04 01:12:56 +0100 |
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committer | Damien Miller <djm@mindrot.org> | 2014-02-04 01:12:56 +0100 |
commit | 7cc194f70d4a5ec9a82d19422eaf18db4a6624c6 (patch) | |
tree | 8bf6b25f93b3ee74dc184349a45125738e89df5b /auth2-jpake.c | |
parent | - djm@cvs.openbsd.org 2014/01/29 00:19:26 (diff) | |
download | openssh-7cc194f70d4a5ec9a82d19422eaf18db4a6624c6.tar.xz openssh-7cc194f70d4a5ec9a82d19422eaf18db4a6624c6.zip |
- djm@cvs.openbsd.org 2014/01/29 06:18:35
[Makefile.in auth.h auth2-jpake.c auth2.c jpake.c jpake.h monitor.c]
[monitor.h monitor_wrap.c monitor_wrap.h readconf.c readconf.h]
[schnorr.c schnorr.h servconf.c servconf.h ssh2.h sshconnect2.c]
remove experimental, never-enabled JPAKE code; ok markus@
Diffstat (limited to 'auth2-jpake.c')
-rw-r--r-- | auth2-jpake.c | 563 |
1 files changed, 0 insertions, 563 deletions
diff --git a/auth2-jpake.c b/auth2-jpake.c deleted file mode 100644 index 78a6b8817..000000000 --- a/auth2-jpake.c +++ /dev/null @@ -1,563 +0,0 @@ -/* $OpenBSD: auth2-jpake.c,v 1.6 2013/05/17 00:13:13 djm Exp $ */ -/* - * Copyright (c) 2008 Damien Miller. All rights reserved. - * - * Permission to use, copy, modify, and distribute this software for any - * purpose with or without fee is hereby granted, provided that the above - * copyright notice and this permission notice appear in all copies. - * - * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES - * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF - * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR - * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES - * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN - * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF - * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. - */ - -/* - * Server side of zero-knowledge password auth using J-PAKE protocol - * as described in: - * - * F. Hao, P. Ryan, "Password Authenticated Key Exchange by Juggling", - * 16th Workshop on Security Protocols, Cambridge, April 2008 - * - * http://grouper.ieee.org/groups/1363/Research/contributions/hao-ryan-2008.pdf - */ - -#ifdef JPAKE - -#include <sys/types.h> -#include <sys/param.h> - -#include <pwd.h> -#include <stdio.h> -#include <string.h> -#include <login_cap.h> - -#include <openssl/bn.h> -#include <openssl/evp.h> - -#include "xmalloc.h" -#include "ssh2.h" -#include "key.h" -#include "hostfile.h" -#include "auth.h" -#include "buffer.h" -#include "packet.h" -#include "dispatch.h" -#include "log.h" -#include "servconf.h" -#include "auth-options.h" -#include "canohost.h" -#ifdef GSSAPI -#include "ssh-gss.h" -#endif -#include "monitor_wrap.h" - -#include "schnorr.h" -#include "jpake.h" - -/* - * XXX options->permit_empty_passwd (at the moment, they will be refused - * anyway because they will mismatch on fake salt. - */ - -/* Dispatch handlers */ -static void input_userauth_jpake_client_step1(int, u_int32_t, void *); -static void input_userauth_jpake_client_step2(int, u_int32_t, void *); -static void input_userauth_jpake_client_confirm(int, u_int32_t, void *); - -static int auth2_jpake_start(Authctxt *); - -/* import */ -extern ServerOptions options; -extern u_char *session_id2; -extern u_int session_id2_len; - -/* - * Attempt J-PAKE authentication. - */ -static int -userauth_jpake(Authctxt *authctxt) -{ - int authenticated = 0; - - packet_check_eom(); - - debug("jpake-01@openssh.com requested"); - - if (authctxt->user != NULL) { - if (authctxt->jpake_ctx == NULL) - authctxt->jpake_ctx = jpake_new(); - if (options.zero_knowledge_password_authentication) - authenticated = auth2_jpake_start(authctxt); - } - - return authenticated; -} - -Authmethod method_jpake = { - "jpake-01@openssh.com", - userauth_jpake, - &options.zero_knowledge_password_authentication -}; - -/* Clear context and callbacks */ -void -auth2_jpake_stop(Authctxt *authctxt) -{ - /* unregister callbacks */ - dispatch_set(SSH2_MSG_USERAUTH_JPAKE_CLIENT_STEP1, NULL); - dispatch_set(SSH2_MSG_USERAUTH_JPAKE_CLIENT_STEP2, NULL); - dispatch_set(SSH2_MSG_USERAUTH_JPAKE_CLIENT_CONFIRM, NULL); - if (authctxt->jpake_ctx != NULL) { - jpake_free(authctxt->jpake_ctx); - authctxt->jpake_ctx = NULL; - } -} - -/* Returns 1 if 'c' is a valid crypt(3) salt character, 0 otherwise */ -static int -valid_crypt_salt(int c) -{ - if (c >= 'A' && c <= 'Z') - return 1; - if (c >= 'a' && c <= 'z') - return 1; - if (c >= '.' && c <= '9') - return 1; - return 0; -} - -/* - * Derive fake salt as H(username || first_private_host_key) - * This provides relatively stable fake salts for non-existent - * users and avoids the jpake method becoming an account validity - * oracle. - */ -static void -derive_rawsalt(const char *username, u_char *rawsalt, u_int len) -{ - u_char *digest; - u_int digest_len; - Buffer b; - Key *k; - - buffer_init(&b); - buffer_put_cstring(&b, username); - if ((k = get_hostkey_by_index(0)) == NULL || - (k->flags & KEY_FLAG_EXT)) - fatal("%s: no hostkeys", __func__); - switch (k->type) { - case KEY_RSA1: - case KEY_RSA: - if (k->rsa->p == NULL || k->rsa->q == NULL) - fatal("%s: RSA key missing p and/or q", __func__); - buffer_put_bignum2(&b, k->rsa->p); - buffer_put_bignum2(&b, k->rsa->q); - break; - case KEY_DSA: - if (k->dsa->priv_key == NULL) - fatal("%s: DSA key missing priv_key", __func__); - buffer_put_bignum2(&b, k->dsa->priv_key); - break; - case KEY_ECDSA: - if (EC_KEY_get0_private_key(k->ecdsa) == NULL) - fatal("%s: ECDSA key missing priv_key", __func__); - buffer_put_bignum2(&b, EC_KEY_get0_private_key(k->ecdsa)); - break; - default: - fatal("%s: unknown key type %d", __func__, k->type); - } - if (hash_buffer(buffer_ptr(&b), buffer_len(&b), EVP_sha256(), - &digest, &digest_len) != 0) - fatal("%s: hash_buffer", __func__); - buffer_free(&b); - if (len > digest_len) - fatal("%s: not enough bytes for rawsalt (want %u have %u)", - __func__, len, digest_len); - memcpy(rawsalt, digest, len); - bzero(digest, digest_len); - free(digest); -} - -/* ASCII an integer [0, 64) for inclusion in a password/salt */ -static char -pw_encode64(u_int i64) -{ - const u_char e64[] = - "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; - return e64[i64 % 64]; -} - -/* Generate ASCII salt bytes for user */ -static char * -makesalt(u_int want, const char *user) -{ - u_char rawsalt[32]; - static char ret[33]; - u_int i; - - if (want > sizeof(ret) - 1) - fatal("%s: want %u", __func__, want); - - derive_rawsalt(user, rawsalt, sizeof(rawsalt)); - bzero(ret, sizeof(ret)); - for (i = 0; i < want; i++) - ret[i] = pw_encode64(rawsalt[i]); - bzero(rawsalt, sizeof(rawsalt)); - - return ret; -} - -/* - * Select the system's default password hashing scheme and generate - * a stable fake salt under it for use by a non-existent account. - * Prevents jpake method being used to infer the validity of accounts. - */ -static void -fake_salt_and_scheme(Authctxt *authctxt, char **salt, char **scheme) -{ - char *rounds_s, *style; - long long rounds; - login_cap_t *lc; - - - if ((lc = login_getclass(authctxt->pw->pw_class)) == NULL && - (lc = login_getclass(NULL)) == NULL) - fatal("%s: login_getclass failed", __func__); - style = login_getcapstr(lc, "localcipher", NULL, NULL); - if (style == NULL) - style = xstrdup("blowfish,6"); - login_close(lc); - - if ((rounds_s = strchr(style, ',')) != NULL) - *rounds_s++ = '\0'; - rounds = strtonum(rounds_s, 1, 1<<31, NULL); - - if (strcmp(style, "md5") == 0) { - xasprintf(salt, "$1$%s$", makesalt(8, authctxt->user)); - *scheme = xstrdup("md5"); - } else if (strcmp(style, "old") == 0) { - *salt = xstrdup(makesalt(2, authctxt->user)); - *scheme = xstrdup("crypt"); - } else if (strcmp(style, "newsalt") == 0) { - rounds = MAX(rounds, 7250); - rounds = MIN(rounds, (1<<24) - 1); - xasprintf(salt, "_%c%c%c%c%s", - pw_encode64(rounds), pw_encode64(rounds >> 6), - pw_encode64(rounds >> 12), pw_encode64(rounds >> 18), - makesalt(4, authctxt->user)); - *scheme = xstrdup("crypt-extended"); - } else { - /* Default to blowfish */ - rounds = MAX(rounds, 3); - rounds = MIN(rounds, 31); - xasprintf(salt, "$2a$%02lld$%s", rounds, - makesalt(22, authctxt->user)); - *scheme = xstrdup("bcrypt"); - } - free(style); - debug3("%s: fake %s salt for user %s: %s", - __func__, *scheme, authctxt->user, *salt); -} - -/* - * Fetch password hashing scheme, password salt and derive shared secret - * for user. If user does not exist, a fake but stable and user-unique - * salt will be returned. - */ -void -auth2_jpake_get_pwdata(Authctxt *authctxt, BIGNUM **s, - char **hash_scheme, char **salt) -{ - char *cp; - u_char *secret; - u_int secret_len, salt_len; - -#ifdef JPAKE_DEBUG - debug3("%s: valid %d pw %.5s...", __func__, - authctxt->valid, authctxt->pw->pw_passwd); -#endif - - *salt = NULL; - *hash_scheme = NULL; - if (authctxt->valid) { - if (strncmp(authctxt->pw->pw_passwd, "$2$", 3) == 0 && - strlen(authctxt->pw->pw_passwd) > 28) { - /* - * old-variant bcrypt: - * "$2$", 2 digit rounds, "$", 22 bytes salt - */ - salt_len = 3 + 2 + 1 + 22 + 1; - *salt = xmalloc(salt_len); - strlcpy(*salt, authctxt->pw->pw_passwd, salt_len); - *hash_scheme = xstrdup("bcrypt"); - } else if (strncmp(authctxt->pw->pw_passwd, "$2a$", 4) == 0 && - strlen(authctxt->pw->pw_passwd) > 29) { - /* - * current-variant bcrypt: - * "$2a$", 2 digit rounds, "$", 22 bytes salt - */ - salt_len = 4 + 2 + 1 + 22 + 1; - *salt = xmalloc(salt_len); - strlcpy(*salt, authctxt->pw->pw_passwd, salt_len); - *hash_scheme = xstrdup("bcrypt"); - } else if (strncmp(authctxt->pw->pw_passwd, "$1$", 3) == 0 && - strlen(authctxt->pw->pw_passwd) > 5) { - /* - * md5crypt: - * "$1$", salt until "$" - */ - cp = strchr(authctxt->pw->pw_passwd + 3, '$'); - if (cp != NULL) { - salt_len = (cp - authctxt->pw->pw_passwd) + 1; - *salt = xmalloc(salt_len); - strlcpy(*salt, authctxt->pw->pw_passwd, - salt_len); - *hash_scheme = xstrdup("md5crypt"); - } - } else if (strncmp(authctxt->pw->pw_passwd, "_", 1) == 0 && - strlen(authctxt->pw->pw_passwd) > 9) { - /* - * BSDI extended crypt: - * "_", 4 digits count, 4 chars salt - */ - salt_len = 1 + 4 + 4 + 1; - *salt = xmalloc(salt_len); - strlcpy(*salt, authctxt->pw->pw_passwd, salt_len); - *hash_scheme = xstrdup("crypt-extended"); - } else if (strlen(authctxt->pw->pw_passwd) == 13 && - valid_crypt_salt(authctxt->pw->pw_passwd[0]) && - valid_crypt_salt(authctxt->pw->pw_passwd[1])) { - /* - * traditional crypt: - * 2 chars salt - */ - salt_len = 2 + 1; - *salt = xmalloc(salt_len); - strlcpy(*salt, authctxt->pw->pw_passwd, salt_len); - *hash_scheme = xstrdup("crypt"); - } - if (*salt == NULL) { - debug("%s: unrecognised crypt scheme for user %s", - __func__, authctxt->pw->pw_name); - } - } - if (*salt == NULL) - fake_salt_and_scheme(authctxt, salt, hash_scheme); - - if (hash_buffer(authctxt->pw->pw_passwd, - strlen(authctxt->pw->pw_passwd), EVP_sha256(), - &secret, &secret_len) != 0) - fatal("%s: hash_buffer", __func__); - if ((*s = BN_bin2bn(secret, secret_len, NULL)) == NULL) - fatal("%s: BN_bin2bn (secret)", __func__); -#ifdef JPAKE_DEBUG - debug3("%s: salt = %s (len %u)", __func__, - *salt, (u_int)strlen(*salt)); - debug3("%s: scheme = %s", __func__, *hash_scheme); - JPAKE_DEBUG_BN((*s, "%s: s = ", __func__)); -#endif - bzero(secret, secret_len); - free(secret); -} - -/* - * Begin authentication attempt. - * Note, sets authctxt->postponed while in subprotocol - */ -static int -auth2_jpake_start(Authctxt *authctxt) -{ - struct jpake_ctx *pctx = authctxt->jpake_ctx; - u_char *x3_proof, *x4_proof; - u_int x3_proof_len, x4_proof_len; - char *salt, *hash_scheme; - - debug("%s: start", __func__); - - PRIVSEP(jpake_step1(pctx->grp, - &pctx->server_id, &pctx->server_id_len, - &pctx->x3, &pctx->x4, &pctx->g_x3, &pctx->g_x4, - &x3_proof, &x3_proof_len, - &x4_proof, &x4_proof_len)); - - PRIVSEP(auth2_jpake_get_pwdata(authctxt, &pctx->s, - &hash_scheme, &salt)); - - if (!use_privsep) - JPAKE_DEBUG_CTX((pctx, "step 1 sending in %s", __func__)); - - packet_start(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP1); - packet_put_cstring(hash_scheme); - packet_put_cstring(salt); - packet_put_string(pctx->server_id, pctx->server_id_len); - packet_put_bignum2(pctx->g_x3); - packet_put_bignum2(pctx->g_x4); - packet_put_string(x3_proof, x3_proof_len); - packet_put_string(x4_proof, x4_proof_len); - packet_send(); - packet_write_wait(); - - bzero(hash_scheme, strlen(hash_scheme)); - bzero(salt, strlen(salt)); - free(hash_scheme); - free(salt); - bzero(x3_proof, x3_proof_len); - bzero(x4_proof, x4_proof_len); - free(x3_proof); - free(x4_proof); - - /* Expect step 1 packet from peer */ - dispatch_set(SSH2_MSG_USERAUTH_JPAKE_CLIENT_STEP1, - input_userauth_jpake_client_step1); - - authctxt->postponed = 1; - return 0; -} - -/* ARGSUSED */ -static void -input_userauth_jpake_client_step1(int type, u_int32_t seq, void *ctxt) -{ - Authctxt *authctxt = ctxt; - struct jpake_ctx *pctx = authctxt->jpake_ctx; - u_char *x1_proof, *x2_proof, *x4_s_proof; - u_int x1_proof_len, x2_proof_len, x4_s_proof_len; - - /* Disable this message */ - dispatch_set(SSH2_MSG_USERAUTH_JPAKE_CLIENT_STEP1, NULL); - - /* Fetch step 1 values */ - if ((pctx->g_x1 = BN_new()) == NULL || - (pctx->g_x2 = BN_new()) == NULL) - fatal("%s: BN_new", __func__); - pctx->client_id = packet_get_string(&pctx->client_id_len); - packet_get_bignum2(pctx->g_x1); - packet_get_bignum2(pctx->g_x2); - x1_proof = packet_get_string(&x1_proof_len); - x2_proof = packet_get_string(&x2_proof_len); - packet_check_eom(); - - if (!use_privsep) - JPAKE_DEBUG_CTX((pctx, "step 1 received in %s", __func__)); - - PRIVSEP(jpake_step2(pctx->grp, pctx->s, pctx->g_x3, - pctx->g_x1, pctx->g_x2, pctx->x4, - pctx->client_id, pctx->client_id_len, - pctx->server_id, pctx->server_id_len, - x1_proof, x1_proof_len, - x2_proof, x2_proof_len, - &pctx->b, - &x4_s_proof, &x4_s_proof_len)); - - bzero(x1_proof, x1_proof_len); - bzero(x2_proof, x2_proof_len); - free(x1_proof); - free(x2_proof); - - if (!use_privsep) - JPAKE_DEBUG_CTX((pctx, "step 2 sending in %s", __func__)); - - /* Send values for step 2 */ - packet_start(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP2); - packet_put_bignum2(pctx->b); - packet_put_string(x4_s_proof, x4_s_proof_len); - packet_send(); - packet_write_wait(); - - bzero(x4_s_proof, x4_s_proof_len); - free(x4_s_proof); - - /* Expect step 2 packet from peer */ - dispatch_set(SSH2_MSG_USERAUTH_JPAKE_CLIENT_STEP2, - input_userauth_jpake_client_step2); -} - -/* ARGSUSED */ -static void -input_userauth_jpake_client_step2(int type, u_int32_t seq, void *ctxt) -{ - Authctxt *authctxt = ctxt; - struct jpake_ctx *pctx = authctxt->jpake_ctx; - u_char *x2_s_proof; - u_int x2_s_proof_len; - - /* Disable this message */ - dispatch_set(SSH2_MSG_USERAUTH_JPAKE_CLIENT_STEP2, NULL); - - if ((pctx->a = BN_new()) == NULL) - fatal("%s: BN_new", __func__); - - /* Fetch step 2 values */ - packet_get_bignum2(pctx->a); - x2_s_proof = packet_get_string(&x2_s_proof_len); - packet_check_eom(); - - if (!use_privsep) - JPAKE_DEBUG_CTX((pctx, "step 2 received in %s", __func__)); - - /* Derive shared key and calculate confirmation hash */ - PRIVSEP(jpake_key_confirm(pctx->grp, pctx->s, pctx->a, - pctx->x4, pctx->g_x3, pctx->g_x4, pctx->g_x1, pctx->g_x2, - pctx->server_id, pctx->server_id_len, - pctx->client_id, pctx->client_id_len, - session_id2, session_id2_len, - x2_s_proof, x2_s_proof_len, - &pctx->k, - &pctx->h_k_sid_sessid, &pctx->h_k_sid_sessid_len)); - - bzero(x2_s_proof, x2_s_proof_len); - free(x2_s_proof); - - if (!use_privsep) - JPAKE_DEBUG_CTX((pctx, "confirm sending in %s", __func__)); - - /* Send key confirmation proof */ - packet_start(SSH2_MSG_USERAUTH_JPAKE_SERVER_CONFIRM); - packet_put_string(pctx->h_k_sid_sessid, pctx->h_k_sid_sessid_len); - packet_send(); - packet_write_wait(); - - /* Expect confirmation from peer */ - dispatch_set(SSH2_MSG_USERAUTH_JPAKE_CLIENT_CONFIRM, - input_userauth_jpake_client_confirm); -} - -/* ARGSUSED */ -static void -input_userauth_jpake_client_confirm(int type, u_int32_t seq, void *ctxt) -{ - Authctxt *authctxt = ctxt; - struct jpake_ctx *pctx = authctxt->jpake_ctx; - int authenticated = 0; - - /* Disable this message */ - dispatch_set(SSH2_MSG_USERAUTH_JPAKE_CLIENT_CONFIRM, NULL); - - pctx->h_k_cid_sessid = packet_get_string(&pctx->h_k_cid_sessid_len); - packet_check_eom(); - - if (!use_privsep) - JPAKE_DEBUG_CTX((pctx, "confirm received in %s", __func__)); - - /* Verify expected confirmation hash */ - if (PRIVSEP(jpake_check_confirm(pctx->k, - pctx->client_id, pctx->client_id_len, - session_id2, session_id2_len, - pctx->h_k_cid_sessid, pctx->h_k_cid_sessid_len)) == 1) - authenticated = authctxt->valid ? 1 : 0; - else - debug("%s: confirmation mismatch", __func__); - - /* done */ - authctxt->postponed = 0; - jpake_free(authctxt->jpake_ctx); - authctxt->jpake_ctx = NULL; - userauth_finish(authctxt, authenticated, method_jpake.name, NULL); -} - -#endif /* JPAKE */ - |