diff options
| -rw-r--r-- | PROTOCOL | 21 | ||||
| -rw-r--r-- | misc.c | 49 | ||||
| -rw-r--r-- | misc.h | 3 | ||||
| -rw-r--r-- | scp.c | 17 | ||||
| -rw-r--r-- | sftp-client.c | 59 | ||||
| -rw-r--r-- | sftp-client.h | 10 | ||||
| -rw-r--r-- | sftp-server.c | 63 |
7 files changed, 187 insertions, 35 deletions
@@ -525,6 +525,25 @@ limits. This extension is advertised in the SSH_FXP_VERSION hello with version "1". +3.9. sftp: Extension request "expand-path@openssh.com" + +This request supports canonicalisation of relative paths and +those that need tilde-expansion, i.e. "~", "~/..." and "~user/..." +These paths are expanded using shell-like rules and the resultant +path is canonicalised similarly to SSH2_FXP_REALPATH. + +It is implemented as a SSH_FXP_EXTENDED request with the following +format: + + uint32 id + string "expand-path@openssh.com" + string path + +Its reply is the same format as that of SSH2_FXP_REALPATH. + +This extension is advertised in the SSH_FXP_VERSION hello with version +"1". + 4. Miscellaneous changes 4.1 Public key format @@ -556,4 +575,4 @@ OpenSSH's connection multiplexing uses messages as described in PROTOCOL.mux over a Unix domain socket for communications between a master instance and later clients. -$OpenBSD: PROTOCOL,v 1.41 2021/02/18 02:49:35 djm Exp $ +$OpenBSD: PROTOCOL,v 1.42 2021/08/09 23:47:44 djm Exp $ @@ -1,4 +1,4 @@ -/* $OpenBSD: misc.c,v 1.168 2021/07/12 06:22:57 dtucker Exp $ */ +/* $OpenBSD: misc.c,v 1.169 2021/08/09 23:47:44 djm Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. * Copyright (c) 2005-2020 Damien Miller. All rights reserved. @@ -1115,29 +1115,37 @@ freeargs(arglist *args) * Expands tildes in the file name. Returns data allocated by xmalloc. * Warning: this calls getpw*. */ -char * -tilde_expand_filename(const char *filename, uid_t uid) +int +tilde_expand(const char *filename, uid_t uid, char **retp) { const char *path, *sep; char user[128], *ret; struct passwd *pw; u_int len, slash; - if (*filename != '~') - return (xstrdup(filename)); + if (*filename != '~') { + *retp = xstrdup(filename); + return 0; + } filename++; path = strchr(filename, '/'); if (path != NULL && path > filename) { /* ~user/path */ slash = path - filename; - if (slash > sizeof(user) - 1) - fatal("tilde_expand_filename: ~username too long"); + if (slash > sizeof(user) - 1) { + error_f("~username too long"); + return -1; + } memcpy(user, filename, slash); user[slash] = '\0'; - if ((pw = getpwnam(user)) == NULL) - fatal("tilde_expand_filename: No such user %s", user); - } else if ((pw = getpwuid(uid)) == NULL) /* ~/path */ - fatal("tilde_expand_filename: No such uid %ld", (long)uid); + if ((pw = getpwnam(user)) == NULL) { + error_f("No such user %s", user); + return -1; + } + } else if ((pw = getpwuid(uid)) == NULL) { /* ~/path */ + error_f("No such uid %ld", (long)uid); + return -1; + } /* Make sure directory has a trailing '/' */ len = strlen(pw->pw_dir); @@ -1150,10 +1158,23 @@ tilde_expand_filename(const char *filename, uid_t uid) if (path != NULL) filename = path + 1; - if (xasprintf(&ret, "%s%s%s", pw->pw_dir, sep, filename) >= PATH_MAX) - fatal("tilde_expand_filename: Path too long"); + if (xasprintf(&ret, "%s%s%s", pw->pw_dir, sep, filename) >= PATH_MAX) { + error_f("Path too long"); + return -1; + } + + *retp = ret; + return 0; +} - return (ret); +char * +tilde_expand_filename(const char *filename, uid_t uid) +{ + char *ret; + + if (tilde_expand(filename, uid, &ret) != 0) + cleanup_exit(255); + return ret; } /* @@ -1,4 +1,4 @@ -/* $OpenBSD: misc.h,v 1.97 2021/06/08 06:54:40 djm Exp $ */ +/* $OpenBSD: misc.h,v 1.98 2021/08/09 23:47:44 djm Exp $ */ /* * Author: Tatu Ylonen <ylo@cs.hut.fi> @@ -71,6 +71,7 @@ int parse_user_host_port(const char *, char **, char **, int *); int parse_uri(const char *, const char *, char **, char **, int *, char **); int convtime(const char *); const char *fmt_timeframe(time_t t); +int tilde_expand(const char *, uid_t, char **); char *tilde_expand_filename(const char *, uid_t); char *dollar_expand(int *, const char *string, ...); @@ -1,4 +1,4 @@ -/* $OpenBSD: scp.c,v 1.226 2021/08/09 23:44:32 djm Exp $ */ +/* $OpenBSD: scp.c,v 1.227 2021/08/09 23:47:44 djm Exp $ */ /* * scp - secure remote copy. This is basically patched BSD rcp which * uses ssh to do the data transfer (instead of using rcmd). @@ -1255,10 +1255,14 @@ tolocal(int argc, char **argv, enum scp_mode_e mode, char *sftp_direct) /* Canonicalise a remote path, handling ~ by assuming cwd is the homedir */ static char * -absolute_remote_path(const char *path, const char *remote_path) +absolute_remote_path(struct sftp_conn *conn, const char *path, + const char *remote_path) { char *ret; + if (can_expand_path(conn)) + return do_expand_path(conn, path); + /* Handle ~ prefixed paths */ if (*path != '~') ret = xstrdup(path); @@ -1296,7 +1300,7 @@ source_sftp(int argc, char *src, char *targ, * No need to glob here - the local shell already took care of * the expansions */ - if ((target = absolute_remote_path(targ, *remote_path)) == NULL) + if ((target = absolute_remote_path(conn, targ, *remote_path)) == NULL) cleanup_exit(255); target_is_dir = remote_is_dir(conn, target); if (targetshouldbedirectory && !target_is_dir) { @@ -1508,7 +1512,7 @@ sink_sftp(int argc, char *dst, const char *src, struct sftp_conn *conn) goto out; } - if ((abs_src = absolute_remote_path(src, remote_path)) == NULL) { + if ((abs_src = absolute_remote_path(conn, src, remote_path)) == NULL) { err = -1; goto out; } @@ -1920,8 +1924,9 @@ throughlocal_sftp(struct sftp_conn *from, struct sftp_conn *to, if ((filename = basename(src)) == NULL) fatal("basename %s: %s", src, strerror(errno)); - if ((abs_src = absolute_remote_path(src, from_remote_path)) == NULL || - (target = absolute_remote_path(targ, *to_remote_path)) == NULL) + if ((abs_src = absolute_remote_path(from, src, + from_remote_path)) == NULL || + (target = absolute_remote_path(to, targ, *to_remote_path)) == NULL) cleanup_exit(255); free(from_remote_path); memset(&g, 0, sizeof(g)); diff --git a/sftp-client.c b/sftp-client.c index ce31c35aa..5bfff90d1 100644 --- a/sftp-client.c +++ b/sftp-client.c @@ -1,4 +1,4 @@ -/* $OpenBSD: sftp-client.c,v 1.153 2021/08/09 07:16:09 djm Exp $ */ +/* $OpenBSD: sftp-client.c,v 1.154 2021/08/09 23:47:44 djm Exp $ */ /* * Copyright (c) 2001-2004 Damien Miller <djm@openbsd.org> * @@ -102,6 +102,7 @@ struct sftp_conn { #define SFTP_EXT_FSYNC 0x00000010 #define SFTP_EXT_LSETSTAT 0x00000020 #define SFTP_EXT_LIMITS 0x00000040 +#define SFTP_EXT_PATH_EXPAND 0x00000080 u_int exts; u_int64_t limit_kbps; struct bwlimit bwlimit_in, bwlimit_out; @@ -529,6 +530,10 @@ do_init(int fd_in, int fd_out, u_int transfer_buflen, u_int num_requests, strcmp((char *)value, "1") == 0) { ret->exts |= SFTP_EXT_LIMITS; known = 1; + } else if (strcmp(name, "expand-path@openssh.com") == 0 && + strcmp((char *)value, "1") == 0) { + ret->exts |= SFTP_EXT_PATH_EXPAND; + known = 1; } if (known) { debug2("Server supports extension \"%s\" revision %s", @@ -964,8 +969,9 @@ do_fsetstat(struct sftp_conn *conn, const u_char *handle, u_int handle_len, return status == SSH2_FX_OK ? 0 : -1; } -char * -do_realpath(struct sftp_conn *conn, const char *path) +/* Implements both the realpath and expand-path operations */ +static char * +do_realpath_expand(struct sftp_conn *conn, const char *path, int expand) { struct sshbuf *msg; u_int expected_id, count, id; @@ -973,14 +979,26 @@ do_realpath(struct sftp_conn *conn, const char *path) Attrib a; u_char type; int r; + const char *what = "SSH2_FXP_REALPATH"; - expected_id = id = conn->msg_id++; - send_string_request(conn, id, SSH2_FXP_REALPATH, path, - strlen(path)); - + if (expand) + what = "expand-path@openssh.com"; if ((msg = sshbuf_new()) == NULL) fatal_f("sshbuf_new failed"); + expected_id = id = conn->msg_id++; + if (expand) { + if ((r = sshbuf_put_u8(msg, SSH2_FXP_EXTENDED)) != 0 || + (r = sshbuf_put_u32(msg, id)) != 0 || + (r = sshbuf_put_cstring(msg, + "expand-path@openssh.com")) != 0 || + (r = sshbuf_put_cstring(msg, path)) != 0) + fatal_fr(r, "compose %s", what); + send_msg(conn, msg); + } else { + send_string_request(conn, id, SSH2_FXP_REALPATH, + path, strlen(path)); + } get_msg(conn, msg); if ((r = sshbuf_get_u8(msg, &type)) != 0 || (r = sshbuf_get_u32(msg, &id)) != 0) @@ -1004,15 +1022,14 @@ do_realpath(struct sftp_conn *conn, const char *path) if ((r = sshbuf_get_u32(msg, &count)) != 0) fatal_fr(r, "parse count"); if (count != 1) - fatal("Got multiple names (%d) from SSH_FXP_REALPATH", count); + fatal("Got multiple names (%d) from %s", count, what); if ((r = sshbuf_get_cstring(msg, &filename, NULL)) != 0 || (r = sshbuf_get_cstring(msg, &longname, NULL)) != 0 || (r = decode_attrib(msg, &a)) != 0) fatal_fr(r, "parse filename/attrib"); - debug3("SSH_FXP_REALPATH %s -> %s size %lu", path, filename, - (unsigned long)a.size); + debug3("%s %s -> %s", what, path, filename); free(longname); @@ -1021,6 +1038,28 @@ do_realpath(struct sftp_conn *conn, const char *path) return(filename); } +char * +do_realpath(struct sftp_conn *conn, const char *path) +{ + return do_realpath_expand(conn, path, 0); +} + +int +can_expand_path(struct sftp_conn *conn) +{ + return (conn->exts & SFTP_EXT_PATH_EXPAND) != 0; +} + +char * +do_expand_path(struct sftp_conn *conn, const char *path) +{ + if (!can_expand_path(conn)) { + debug3_f("no server support, fallback to realpath"); + return do_realpath_expand(conn, path, 0); + } + return do_realpath_expand(conn, path, 1); +} + int do_rename(struct sftp_conn *conn, const char *oldpath, const char *newpath, int force_legacy) diff --git a/sftp-client.h b/sftp-client.h index 00707f7ce..7d0bd12ae 100644 --- a/sftp-client.h +++ b/sftp-client.h @@ -1,4 +1,4 @@ -/* $OpenBSD: sftp-client.h,v 1.33 2021/08/07 00:12:09 djm Exp $ */ +/* $OpenBSD: sftp-client.h,v 1.34 2021/08/09 23:47:44 djm Exp $ */ /* * Copyright (c) 2001-2004 Damien Miller <djm@openbsd.org> @@ -113,11 +113,17 @@ int do_lsetstat(struct sftp_conn *conn, const char *path, Attrib *a); /* Canonicalise 'path' - caller must free result */ char *do_realpath(struct sftp_conn *, const char *); +/* Canonicalisation with tilde expansion (requires server extension) */ +char *do_expand_path(struct sftp_conn *, const char *); + +/* Returns non-zero if server can tilde-expand paths */ +int can_expand_path(struct sftp_conn *); + /* Get statistics for filesystem hosting file at "path" */ int do_statvfs(struct sftp_conn *, const char *, struct sftp_statvfs *, int); /* Rename 'oldpath' to 'newpath' */ -int do_rename(struct sftp_conn *, const char *, const char *, int force_legacy); +int do_rename(struct sftp_conn *, const char *, const char *, int); /* Link 'oldpath' to 'newpath' */ int do_hardlink(struct sftp_conn *, const char *, const char *); diff --git a/sftp-server.c b/sftp-server.c index c89c1f424..18d194911 100644 --- a/sftp-server.c +++ b/sftp-server.c @@ -1,4 +1,4 @@ -/* $OpenBSD: sftp-server.c,v 1.128 2021/06/06 03:15:39 djm Exp $ */ +/* $OpenBSD: sftp-server.c,v 1.129 2021/08/09 23:47:44 djm Exp $ */ /* * Copyright (c) 2000-2004 Markus Friedl. All rights reserved. * @@ -115,6 +115,7 @@ static void process_extended_hardlink(u_int32_t id); static void process_extended_fsync(u_int32_t id); static void process_extended_lsetstat(u_int32_t id); static void process_extended_limits(u_int32_t id); +static void process_extended_expand(u_int32_t id); static void process_extended(u_int32_t id); struct sftp_handler { @@ -158,6 +159,8 @@ static const struct sftp_handler extended_handlers[] = { { "fsync", "fsync@openssh.com", 0, process_extended_fsync, 1 }, { "lsetstat", "lsetstat@openssh.com", 0, process_extended_lsetstat, 1 }, { "limits", "limits@openssh.com", 0, process_extended_limits, 0 }, + { "expand-path", "expand-path@openssh.com", 0, + process_extended_expand, 0 }, { NULL, NULL, 0, NULL, 0 } }; @@ -706,6 +709,7 @@ process_init(void) compose_extension(msg, "fsync@openssh.com", "1"); compose_extension(msg, "lsetstat@openssh.com", "1"); compose_extension(msg, "limits@openssh.com", "1"); + compose_extension(msg, "expand-path@openssh.com", "1"); send_msg(msg); sshbuf_free(msg); @@ -1520,6 +1524,63 @@ process_extended_limits(u_int32_t id) } static void +process_extended_expand(u_int32_t id) +{ + char cwd[PATH_MAX], resolvedname[PATH_MAX]; + char *path, *npath; + int r; + Stat s; + + if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0) + fatal_fr(r, "parse"); + if (getcwd(cwd, sizeof(cwd)) == NULL) { + send_status(id, errno_to_portable(errno)); + goto out; + } + + debug3("request %u: expand, original \"%s\"", id, path); + if (path[0] == '\0') { + /* empty path */ + free(path); + path = xstrdup("."); + } else if (*path == '~') { + /* ~ expand path */ + /* Special-case for "~" and "~/" to respect homedir flag */ + if (strcmp(path, "~") == 0) { + free(path); + path = xstrdup(cwd); + } else if (strncmp(path, "~/", 2) == 0) { + npath = xstrdup(path + 2); + free(path); + xasprintf(&path, "%s/%s", cwd, npath); + } else { + /* ~user expansions */ + if (tilde_expand(path, pw->pw_uid, &npath) != 0) { + send_status(id, errno_to_portable(EINVAL)); + goto out; + } + free(path); + path = npath; + } + } else if (*path != '/') { + /* relative path */ + xasprintf(&npath, "%s/%s", cwd, path); + free(path); + path = npath; + } + verbose("expand \"%s\"", path); + if (sftp_realpath(path, resolvedname) == NULL) { + send_status(id, errno_to_portable(errno)); + goto out; + } + attrib_clear(&s.attrib); + s.name = s.long_name = resolvedname; + send_names(id, 1, &s); + out: + free(path); +} + +static void process_extended(u_int32_t id) { char *request; |