From 5e820e9ea2e949aeb93071fe31c80b0c42f2b2de Mon Sep 17 00:00:00 2001 From: "djm@openbsd.org" Date: Fri, 6 Jan 2017 03:53:58 +0000 Subject: upstream commit show a useful error message when included config files can't be opened; bz#2653, ok dtucker@ Upstream-ID: f598b73b5dfe497344cec9efc9386b4e5a3cb95b --- readconf.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'readconf.c') diff --git a/readconf.c b/readconf.c index fa3fab8f0..3588ee906 100644 --- a/readconf.c +++ b/readconf.c @@ -1,4 +1,4 @@ -/* $OpenBSD: readconf.c,v 1.262 2016/10/25 04:08:13 jsg Exp $ */ +/* $OpenBSD: readconf.c,v 1.263 2017/01/06 03:53:58 djm Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -1502,6 +1502,11 @@ parse_keytypes: flags | SSHCONF_CHECKPERM | (oactive ? 0 : SSHCONF_NEVERMATCH), activep, depth + 1); + if (errno != ENOENT) { + fatal("Can't open user config file " + "%.100s: %.100s", gl.gl_pathv[i], + strerror(errno)); + } /* * don't let Match in includes clobber the * containing file's Match state. -- cgit v1.2.3 From b64077f9767634715402014f509e58decf1e140d Mon Sep 17 00:00:00 2001 From: "djm@openbsd.org" Date: Fri, 6 Jan 2017 09:27:52 +0000 Subject: upstream commit fix previous Upstream-ID: c107d6a69bc22325d79fbf78a2a62e04bcac6895 --- readconf.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'readconf.c') diff --git a/readconf.c b/readconf.c index 3588ee906..7194b0ccc 100644 --- a/readconf.c +++ b/readconf.c @@ -1,4 +1,4 @@ -/* $OpenBSD: readconf.c,v 1.263 2017/01/06 03:53:58 djm Exp $ */ +/* $OpenBSD: readconf.c,v 1.264 2017/01/06 09:27:52 djm Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -1502,7 +1502,7 @@ parse_keytypes: flags | SSHCONF_CHECKPERM | (oactive ? 0 : SSHCONF_NEVERMATCH), activep, depth + 1); - if (errno != ENOENT) { + if (r != 1 && errno != ENOENT) { fatal("Can't open user config file " "%.100s: %.100s", gl.gl_pathv[i], strerror(errno)); -- cgit v1.2.3 From 4833d01591b7eb049489d9558b65f5553387ed43 Mon Sep 17 00:00:00 2001 From: "djm@openbsd.org" Date: Mon, 30 Jan 2017 00:34:01 +0000 Subject: upstream commit some explicit NULL tests when dumping configured forwardings; from Karsten Weiss Upstream-ID: 40957b8dea69672b0e50df6b4a91a94e3e37f72d --- readconf.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'readconf.c') diff --git a/readconf.c b/readconf.c index 7194b0ccc..5064e33ee 100644 --- a/readconf.c +++ b/readconf.c @@ -1,4 +1,4 @@ -/* $OpenBSD: readconf.c,v 1.264 2017/01/06 09:27:52 djm Exp $ */ +/* $OpenBSD: readconf.c,v 1.265 2017/01/30 00:34:01 djm Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -2451,10 +2451,10 @@ dump_cfg_forwards(OpCodes code, u_int count, const struct Forward *fwds) /* oDynamicForward */ for (i = 0; i < count; i++) { fwd = &fwds[i]; - if (code == oDynamicForward && + if (code == oDynamicForward && fwd->connect_host != NULL && strcmp(fwd->connect_host, "socks") != 0) continue; - if (code == oLocalForward && + if (code == oLocalForward && fwd->connect_host != NULL && strcmp(fwd->connect_host, "socks") == 0) continue; printf("%s", lookup_opcode_name(code)); -- cgit v1.2.3 From 381a2615a154a82c4c53b787f4a564ef894fe9ac Mon Sep 17 00:00:00 2001 From: "djm@openbsd.org" Date: Mon, 30 Jan 2017 00:38:50 +0000 Subject: upstream commit small cleanup post SSHv1 removal: remove SSHv1-isms in commented examples reorder token table to group deprecated and compile-time conditional tokens better fix config dumping code for some compile-time conditional options that weren't being correctly skipped (SSHv1 and PKCS#11) Upstream-ID: f2e96b3cb3158d857c5a91ad2e15925df3060105 --- readconf.c | 76 ++++++++++++++++++++++++++++++++++++++------------------------ 1 file changed, 47 insertions(+), 29 deletions(-) (limited to 'readconf.c') diff --git a/readconf.c b/readconf.c index 5064e33ee..72b4a637c 100644 --- a/readconf.c +++ b/readconf.c @@ -1,4 +1,4 @@ -/* $OpenBSD: readconf.c,v 1.265 2017/01/30 00:34:01 djm Exp $ */ +/* $OpenBSD: readconf.c,v 1.266 2017/01/30 00:38:50 djm Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -93,7 +93,7 @@ Host books.com RemoteForward 9999 shadows.cs.hut.fi:9999 - Cipher 3des + Ciphers 3des-cbc Host fascist.blob.com Port 23123 @@ -108,7 +108,7 @@ PublicKeyAuthentication no Host *.su - Cipher none + Ciphers aes128-ctr PasswordAuthentication no Host vpn.fake.com @@ -180,6 +180,44 @@ static struct { const char *name; OpCodes opcode; } keywords[] = { + /* Deprecated options */ + { "fallbacktorsh", oDeprecated }, + { "globalknownhostsfile2", oDeprecated }, + { "rhostsauthentication", oDeprecated }, + { "userknownhostsfile2", oDeprecated }, + { "useroaming", oDeprecated }, + { "usersh", oDeprecated }, + + /* Unsupported options */ + { "afstokenpassing", oUnsupported }, + { "kerberosauthentication", oUnsupported }, + { "kerberostgtpassing", oUnsupported }, + + /* Sometimes-unsupported options */ +#if defined(GSSAPI) + { "gssapiauthentication", oGssAuthentication }, + { "gssapidelegatecredentials", oGssDelegateCreds }, +# else + { "gssapiauthentication", oUnsupported }, + { "gssapidelegatecredentials", oUnsupported }, +#endif +#ifdef ENABLE_PKCS11 + { "smartcarddevice", oPKCS11Provider }, + { "pkcs11provider", oPKCS11Provider }, +# else + { "smartcarddevice", oUnsupported }, + { "pkcs11provider", oUnsupported }, +#endif +#ifdef WITH_SSH1 + { "rsaauthentication", oRSAAuthentication }, + { "rhostsrsaauthentication", oRhostsRSAAuthentication }, + { "compressionlevel", oCompressionLevel }, +# else + { "rsaauthentication", oUnsupported }, + { "rhostsrsaauthentication", oUnsupported }, + { "compressionlevel", oUnsupported }, +#endif + { "forwardagent", oForwardAgent }, { "forwardx11", oForwardX11 }, { "forwardx11trusted", oForwardX11Trusted }, @@ -188,30 +226,15 @@ static struct { { "xauthlocation", oXAuthLocation }, { "gatewayports", oGatewayPorts }, { "useprivilegedport", oUsePrivilegedPort }, - { "rhostsauthentication", oDeprecated }, { "passwordauthentication", oPasswordAuthentication }, { "kbdinteractiveauthentication", oKbdInteractiveAuthentication }, { "kbdinteractivedevices", oKbdInteractiveDevices }, - { "rsaauthentication", oRSAAuthentication }, { "pubkeyauthentication", oPubkeyAuthentication }, { "dsaauthentication", oPubkeyAuthentication }, /* alias */ - { "rhostsrsaauthentication", oRhostsRSAAuthentication }, { "hostbasedauthentication", oHostbasedAuthentication }, { "challengeresponseauthentication", oChallengeResponseAuthentication }, { "skeyauthentication", oChallengeResponseAuthentication }, /* alias */ { "tisauthentication", oChallengeResponseAuthentication }, /* alias */ - { "kerberosauthentication", oUnsupported }, - { "kerberostgtpassing", oUnsupported }, - { "afstokenpassing", oUnsupported }, -#if defined(GSSAPI) - { "gssapiauthentication", oGssAuthentication }, - { "gssapidelegatecredentials", oGssDelegateCreds }, -#else - { "gssapiauthentication", oUnsupported }, - { "gssapidelegatecredentials", oUnsupported }, -#endif - { "fallbacktorsh", oDeprecated }, - { "usersh", oDeprecated }, { "identityfile", oIdentityFile }, { "identityfile2", oIdentityFile }, /* obsolete */ { "identitiesonly", oIdentitiesOnly }, @@ -233,15 +256,12 @@ static struct { { "match", oMatch }, { "escapechar", oEscapeChar }, { "globalknownhostsfile", oGlobalKnownHostsFile }, - { "globalknownhostsfile2", oDeprecated }, { "userknownhostsfile", oUserKnownHostsFile }, - { "userknownhostsfile2", oDeprecated }, { "connectionattempts", oConnectionAttempts }, { "batchmode", oBatchMode }, { "checkhostip", oCheckHostIP }, { "stricthostkeychecking", oStrictHostKeyChecking }, { "compression", oCompression }, - { "compressionlevel", oCompressionLevel }, { "tcpkeepalive", oTCPKeepAlive }, { "keepalive", oTCPKeepAlive }, /* obsolete */ { "numberofpasswordprompts", oNumberOfPasswordPrompts }, @@ -250,13 +270,6 @@ static struct { { "preferredauthentications", oPreferredAuthentications }, { "hostkeyalgorithms", oHostKeyAlgorithms }, { "bindaddress", oBindAddress }, -#ifdef ENABLE_PKCS11 - { "smartcarddevice", oPKCS11Provider }, - { "pkcs11provider", oPKCS11Provider }, -#else - { "smartcarddevice", oUnsupported }, - { "pkcs11provider", oUnsupported }, -#endif { "clearallforwardings", oClearAllForwardings }, { "enablesshkeysign", oEnableSSHKeysign }, { "verifyhostkeydns", oVerifyHostKeyDNS }, @@ -277,7 +290,6 @@ static struct { { "localcommand", oLocalCommand }, { "permitlocalcommand", oPermitLocalCommand }, { "visualhostkey", oVisualHostKey }, - { "useroaming", oDeprecated }, { "kexalgorithms", oKexAlgorithms }, { "ipqos", oIPQoS }, { "requesttty", oRequestTTY }, @@ -2527,8 +2539,10 @@ dump_client_config(Options *o, const char *host) dump_cfg_fmtint(oProxyUseFdpass, o->proxy_use_fdpass); dump_cfg_fmtint(oPubkeyAuthentication, o->pubkey_authentication); dump_cfg_fmtint(oRequestTTY, o->request_tty); +#ifdef WITH_RSA1 dump_cfg_fmtint(oRhostsRSAAuthentication, o->rhosts_rsa_authentication); dump_cfg_fmtint(oRSAAuthentication, o->rsa_authentication); +#endif dump_cfg_fmtint(oStreamLocalBindUnlink, o->fwd_opts.streamlocal_bind_unlink); dump_cfg_fmtint(oStrictHostKeyChecking, o->strict_host_key_checking); dump_cfg_fmtint(oTCPKeepAlive, o->tcp_keep_alive); @@ -2540,7 +2554,9 @@ dump_client_config(Options *o, const char *host) /* Integer options */ dump_cfg_int(oCanonicalizeMaxDots, o->canonicalize_max_dots); +#ifdef WITH_SSH1 dump_cfg_int(oCompressionLevel, o->compression_level); +#endif dump_cfg_int(oConnectionAttempts, o->connection_attempts); dump_cfg_int(oForwardX11Timeout, o->forward_x11_timeout); dump_cfg_int(oNumberOfPasswordPrompts, o->number_of_password_prompts); @@ -2560,7 +2576,9 @@ dump_client_config(Options *o, const char *host) dump_cfg_string(oLocalCommand, o->local_command); dump_cfg_string(oLogLevel, log_level_name(o->log_level)); dump_cfg_string(oMacs, o->macs ? o->macs : KEX_CLIENT_MAC); +#ifdef ENABLE_PKCS11 dump_cfg_string(oPKCS11Provider, o->pkcs11_provider); +#endif dump_cfg_string(oPreferredAuthentications, o->preferred_authentications); dump_cfg_string(oPubkeyAcceptedKeyTypes, o->pubkey_key_types); dump_cfg_string(oRevokedHostKeys, o->revoked_host_keys); -- cgit v1.2.3 From c924b2ef941028a1f31e6e94f54dfeeeef462a4e Mon Sep 17 00:00:00 2001 From: "djm@openbsd.org" Date: Fri, 3 Feb 2017 05:05:56 +0000 Subject: upstream commit allow form-feed characters at EOL; bz#2431 ok dtucker@ Upstream-ID: 1f453afaba6da2ae69d6afdf1ae79a917552f1a2 --- readconf.c | 6 +++--- servconf.c | 11 ++++++++++- 2 files changed, 13 insertions(+), 4 deletions(-) (limited to 'readconf.c') diff --git a/readconf.c b/readconf.c index 72b4a637c..6c934406e 100644 --- a/readconf.c +++ b/readconf.c @@ -1,4 +1,4 @@ -/* $OpenBSD: readconf.c,v 1.266 2017/01/30 00:38:50 djm Exp $ */ +/* $OpenBSD: readconf.c,v 1.267 2017/02/03 05:05:56 djm Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -842,11 +842,11 @@ process_config_line_depth(Options *options, struct passwd *pw, const char *host, activep = &cmdline; } - /* Strip trailing whitespace */ + /* Strip trailing whitespace. Allow \f (form feed) at EOL only */ if ((len = strlen(line)) == 0) return 0; for (len--; len > 0; len--) { - if (strchr(WHITESPACE, line[len]) == NULL) + if (strchr(WHITESPACE "\f", line[len]) == NULL) break; line[len] = '\0'; } diff --git a/servconf.c b/servconf.c index c9105a592..1880b8cfd 100644 --- a/servconf.c +++ b/servconf.c @@ -1,5 +1,5 @@ -/* $OpenBSD: servconf.c,v 1.302 2017/01/06 03:45:41 djm Exp $ */ +/* $OpenBSD: servconf.c,v 1.303 2017/02/03 05:05:56 djm Exp $ */ /* * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland * All rights reserved @@ -966,6 +966,15 @@ process_server_config_line(ServerOptions *options, char *line, long long val64; const struct multistate *multistate_ptr; + /* Strip trailing whitespace. Allow \f (form feed) at EOL only */ + if ((len = strlen(line)) == 0) + return 0; + for (len--; len > 0; len--) { + if (strchr(WHITESPACE "\f", line[len]) == NULL) + break; + line[len] = '\0'; + } + cp = line; if ((arg = strdelim(&cp)) == NULL) return 0; -- cgit v1.2.3 From 68bc8cfa7642d3ccbf2cd64281c16b8b9205be59 Mon Sep 17 00:00:00 2001 From: "djm@openbsd.org" Date: Fri, 3 Feb 2017 23:01:19 +0000 Subject: upstream commit support =- for removing methods from algorithms lists, e.g. Ciphers=-*cbc; suggested by Cristian Ionescu-Idbohrn in bz#2671 "I like it" markus@ Upstream-ID: c78c38f9f81a963b33d0eade559f6048add24a6d --- compat.c | 48 +++++++++++++----------------------------------- kex.c | 21 +++++++++++++-------- match.c | 31 ++++++++++++++++++++++++++++++- match.h | 3 ++- readconf.c | 12 +++++++----- servconf.c | 12 +++++++----- ssh_config.5 | 28 ++++++++++++++++++++++++++-- sshd_config.5 | 24 ++++++++++++++++++++++-- 8 files changed, 120 insertions(+), 59 deletions(-) (limited to 'readconf.c') diff --git a/compat.c b/compat.c index 69a104fbf..1e80cfa9a 100644 --- a/compat.c +++ b/compat.c @@ -1,4 +1,4 @@ -/* $OpenBSD: compat.c,v 1.99 2016/05/24 02:31:57 dtucker Exp $ */ +/* $OpenBSD: compat.c,v 1.100 2017/02/03 23:01:19 djm Exp $ */ /* * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved. * @@ -37,6 +37,7 @@ #include "compat.h" #include "log.h" #include "match.h" +#include "kex.h" int compat13 = 0; int compat20 = 0; @@ -250,42 +251,14 @@ proto_spec(const char *spec) return ret; } -/* - * Filters a proposal string, excluding any algorithm matching the 'filter' - * pattern list. - */ -static char * -filter_proposal(char *proposal, const char *filter) -{ - Buffer b; - char *orig_prop, *fix_prop; - char *cp, *tmp; - - buffer_init(&b); - tmp = orig_prop = xstrdup(proposal); - while ((cp = strsep(&tmp, ",")) != NULL) { - if (match_pattern_list(cp, filter, 0) != 1) { - if (buffer_len(&b) > 0) - buffer_append(&b, ",", 1); - buffer_append(&b, cp, strlen(cp)); - } else - debug2("Compat: skipping algorithm \"%s\"", cp); - } - buffer_append(&b, "\0", 1); - fix_prop = xstrdup((char *)buffer_ptr(&b)); - buffer_free(&b); - free(orig_prop); - - return fix_prop; -} - char * compat_cipher_proposal(char *cipher_prop) { if (!(datafellows & SSH_BUG_BIGENDIANAES)) return cipher_prop; debug2("%s: original cipher proposal: %s", __func__, cipher_prop); - cipher_prop = filter_proposal(cipher_prop, "aes*"); + if ((cipher_prop = match_filter_list(cipher_prop, "aes*")) == NULL) + fatal("match_filter_list failed"); debug2("%s: compat cipher proposal: %s", __func__, cipher_prop); if (*cipher_prop == '\0') fatal("No supported ciphers found"); @@ -298,7 +271,8 @@ compat_pkalg_proposal(char *pkalg_prop) if (!(datafellows & SSH_BUG_RSASIGMD5)) return pkalg_prop; debug2("%s: original public key proposal: %s", __func__, pkalg_prop); - pkalg_prop = filter_proposal(pkalg_prop, "ssh-rsa"); + if ((pkalg_prop = match_filter_list(pkalg_prop, "ssh-rsa")) == NULL) + fatal("match_filter_list failed"); debug2("%s: compat public key proposal: %s", __func__, pkalg_prop); if (*pkalg_prop == '\0') fatal("No supported PK algorithms found"); @@ -312,10 +286,14 @@ compat_kex_proposal(char *p) return p; debug2("%s: original KEX proposal: %s", __func__, p); if ((datafellows & SSH_BUG_CURVE25519PAD) != 0) - p = filter_proposal(p, "curve25519-sha256@libssh.org"); + if ((p = match_filter_list(p, + "curve25519-sha256@libssh.org")) == NULL) + fatal("match_filter_list failed"); if ((datafellows & SSH_OLD_DHGEX) != 0) { - p = filter_proposal(p, "diffie-hellman-group-exchange-sha256"); - p = filter_proposal(p, "diffie-hellman-group-exchange-sha1"); + if ((p = match_filter_list(p, + "diffie-hellman-group-exchange-sha256," + "diffie-hellman-group-exchange-sha1")) == NULL) + fatal("match_filter_list failed"); } debug2("%s: compat KEX proposal: %s", __func__, p); if (*p == '\0') diff --git a/kex.c b/kex.c index 6a94bc535..a30dabe5f 100644 --- a/kex.c +++ b/kex.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kex.c,v 1.127 2016/10/10 19:28:48 markus Exp $ */ +/* $OpenBSD: kex.c,v 1.128 2017/02/03 23:01:19 djm Exp $ */ /* * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. * @@ -211,7 +211,8 @@ kex_names_cat(const char *a, const char *b) /* * Assemble a list of algorithms from a default list and a string from a * configuration file. The user-provided string may begin with '+' to - * indicate that it should be appended to the default. + * indicate that it should be appended to the default or '-' that the + * specified names should be removed. */ int kex_assemble_names(const char *def, char **list) @@ -222,14 +223,18 @@ kex_assemble_names(const char *def, char **list) *list = strdup(def); return 0; } - if (**list != '+') { - return 0; + if (**list == '+') { + if ((ret = kex_names_cat(def, *list + 1)) == NULL) + return SSH_ERR_ALLOC_FAIL; + free(*list); + *list = ret; + } else if (**list == '-') { + if ((ret = match_filter_list(def, *list + 1)) == NULL) + return SSH_ERR_ALLOC_FAIL; + free(*list); + *list = ret; } - if ((ret = kex_names_cat(def, *list + 1)) == NULL) - return SSH_ERR_ALLOC_FAIL; - free(*list); - *list = ret; return 0; } diff --git a/match.c b/match.c index c15dcd1ef..aeba4bb77 100644 --- a/match.c +++ b/match.c @@ -1,4 +1,4 @@ -/* $OpenBSD: match.c,v 1.33 2016/11/06 05:46:37 djm Exp $ */ +/* $OpenBSD: match.c,v 1.34 2017/02/03 23:01:19 djm Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -284,3 +284,32 @@ match_list(const char *client, const char *server, u_int *next) free(s); return NULL; } + +/* + * Filters a comma-separated list of strings, excluding any entry matching + * the 'filter' pattern list. Caller must free returned string. + */ +char * +match_filter_list(const char *proposal, const char *filter) +{ + size_t len = strlen(proposal) + 1; + char *fix_prop = malloc(len); + char *orig_prop = strdup(proposal); + char *cp, *tmp; + + if (fix_prop == NULL || orig_prop == NULL) + return NULL; + + tmp = orig_prop; + *fix_prop = '\0'; + while ((cp = strsep(&tmp, ",")) != NULL) { + if (match_pattern_list(cp, filter, 0) != 1) { + if (*fix_prop != '\0') + strlcat(fix_prop, ",", len); + strlcat(fix_prop, cp, len); + } + } + free(orig_prop); + return fix_prop; +} + diff --git a/match.h b/match.h index db97ca8f7..937ba0412 100644 --- a/match.h +++ b/match.h @@ -1,4 +1,4 @@ -/* $OpenBSD: match.h,v 1.16 2015/05/04 06:10:48 djm Exp $ */ +/* $OpenBSD: match.h,v 1.17 2017/02/03 23:01:19 djm Exp $ */ /* * Author: Tatu Ylonen @@ -20,6 +20,7 @@ int match_hostname(const char *, const char *); int match_host_and_ip(const char *, const char *, const char *); int match_user(const char *, const char *, const char *, const char *); char *match_list(const char *, const char *, u_int *); +char *match_filter_list(const char *, const char *); /* addrmatch.c */ int addr_match_list(const char *, const char *); diff --git a/readconf.c b/readconf.c index 6c934406e..e51481b10 100644 --- a/readconf.c +++ b/readconf.c @@ -1,4 +1,4 @@ -/* $OpenBSD: readconf.c,v 1.267 2017/02/03 05:05:56 djm Exp $ */ +/* $OpenBSD: readconf.c,v 1.268 2017/02/03 23:01:19 djm Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -1194,7 +1194,7 @@ parse_int: arg = strdelim(&s); if (!arg || *arg == '\0') fatal("%.200s line %d: Missing argument.", filename, linenum); - if (!ciphers_valid(*arg == '+' ? arg + 1 : arg)) + if (*arg != '-' && !ciphers_valid(*arg == '+' ? arg + 1 : arg)) fatal("%.200s line %d: Bad SSH2 cipher spec '%s'.", filename, linenum, arg ? arg : ""); if (*activep && options->ciphers == NULL) @@ -1205,7 +1205,7 @@ parse_int: arg = strdelim(&s); if (!arg || *arg == '\0') fatal("%.200s line %d: Missing argument.", filename, linenum); - if (!mac_valid(*arg == '+' ? arg + 1 : arg)) + if (*arg != '-' && !mac_valid(*arg == '+' ? arg + 1 : arg)) fatal("%.200s line %d: Bad SSH2 Mac spec '%s'.", filename, linenum, arg ? arg : ""); if (*activep && options->macs == NULL) @@ -1217,7 +1217,8 @@ parse_int: if (!arg || *arg == '\0') fatal("%.200s line %d: Missing argument.", filename, linenum); - if (!kex_names_valid(*arg == '+' ? arg + 1 : arg)) + if (*arg != '-' && + !kex_names_valid(*arg == '+' ? arg + 1 : arg)) fatal("%.200s line %d: Bad SSH2 KexAlgorithms '%s'.", filename, linenum, arg ? arg : ""); if (*activep && options->kex_algorithms == NULL) @@ -1231,7 +1232,8 @@ parse_keytypes: if (!arg || *arg == '\0') fatal("%.200s line %d: Missing argument.", filename, linenum); - if (!sshkey_names_valid2(*arg == '+' ? arg + 1 : arg, 1)) + if (*arg != '-' && + !sshkey_names_valid2(*arg == '+' ? arg + 1 : arg, 1)) fatal("%s line %d: Bad key types '%s'.", filename, linenum, arg ? arg : ""); if (*activep && *charptr == NULL) diff --git a/servconf.c b/servconf.c index 1880b8cfd..2f8e29d4c 100644 --- a/servconf.c +++ b/servconf.c @@ -1,5 +1,5 @@ -/* $OpenBSD: servconf.c,v 1.303 2017/02/03 05:05:56 djm Exp $ */ +/* $OpenBSD: servconf.c,v 1.304 2017/02/03 23:01:19 djm Exp $ */ /* * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland * All rights reserved @@ -1177,7 +1177,8 @@ process_server_config_line(ServerOptions *options, char *line, if (!arg || *arg == '\0') fatal("%s line %d: Missing argument.", filename, linenum); - if (!sshkey_names_valid2(*arg == '+' ? arg + 1 : arg, 1)) + if (*arg != '-' && + !sshkey_names_valid2(*arg == '+' ? arg + 1 : arg, 1)) fatal("%s line %d: Bad key types '%s'.", filename, linenum, arg ? arg : ""); if (*activep && *charptr == NULL) @@ -1436,7 +1437,7 @@ process_server_config_line(ServerOptions *options, char *line, arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: Missing argument.", filename, linenum); - if (!ciphers_valid(*arg == '+' ? arg + 1 : arg)) + if (*arg != '-' && !ciphers_valid(*arg == '+' ? arg + 1 : arg)) fatal("%s line %d: Bad SSH2 cipher spec '%s'.", filename, linenum, arg ? arg : ""); if (options->ciphers == NULL) @@ -1447,7 +1448,7 @@ process_server_config_line(ServerOptions *options, char *line, arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: Missing argument.", filename, linenum); - if (!mac_valid(*arg == '+' ? arg + 1 : arg)) + if (*arg != '-' && !mac_valid(*arg == '+' ? arg + 1 : arg)) fatal("%s line %d: Bad SSH2 mac spec '%s'.", filename, linenum, arg ? arg : ""); if (options->macs == NULL) @@ -1459,7 +1460,8 @@ process_server_config_line(ServerOptions *options, char *line, if (!arg || *arg == '\0') fatal("%s line %d: Missing argument.", filename, linenum); - if (!kex_names_valid(*arg == '+' ? arg + 1 : arg)) + if (*arg != '-' && + !kex_names_valid(*arg == '+' ? arg + 1 : arg)) fatal("%s line %d: Bad SSH2 KexAlgorithms '%s'.", filename, linenum, arg ? arg : ""); if (options->kex_algorithms == NULL) diff --git a/ssh_config.5 b/ssh_config.5 index 591365f34..016adbc73 100644 --- a/ssh_config.5 +++ b/ssh_config.5 @@ -33,8 +33,8 @@ .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. .\" -.\" $OpenBSD: ssh_config.5,v 1.240 2016/10/15 19:56:25 jmc Exp $ -.Dd $Mdocdate: October 15 2016 $ +.\" $OpenBSD: ssh_config.5,v 1.241 2017/02/03 23:01:19 djm Exp $ +.Dd $Mdocdate: February 3 2017 $ .Dt SSH_CONFIG 5 .Os .Sh NAME @@ -415,6 +415,10 @@ If the specified value begins with a .Sq + character, then the specified ciphers will be appended to the default set instead of replacing them. +If the specified value begins with a +.Sq - +character, then the specified ciphers (including wildcards) will be removed +from the default set instead of replacing them. .Pp The supported ciphers are: .Bd -literal -offset indent @@ -784,6 +788,10 @@ Alternately if the specified value begins with a .Sq + character, then the specified key types will be appended to the default set instead of replacing them. +If the specified value begins with a +.Sq - +character, then the specified key types (including wildcards) will be removed +from the default set instead of replacing them. The default for this option is: .Bd -literal -offset 3n ecdsa-sha2-nistp256-cert-v01@openssh.com, @@ -807,6 +815,10 @@ Alternately if the specified value begins with a .Sq + character, then the specified key types will be appended to the default set instead of replacing them. +If the specified value begins with a +.Sq - +character, then the specified key types (including wildcards) will be removed +from the default set instead of replacing them. The default for this option is: .Bd -literal -offset 3n ecdsa-sha2-nistp256-cert-v01@openssh.com, @@ -1027,6 +1039,10 @@ Alternately if the specified value begins with a .Sq + character, then the specified methods will be appended to the default set instead of replacing them. +If the specified value begins with a +.Sq - +character, then the specified methods (including wildcards) will be removed +from the default set instead of replacing them. The default is: .Bd -literal -offset indent curve25519-sha256,curve25519-sha256@libssh.org, @@ -1102,6 +1118,10 @@ If the specified value begins with a .Sq + character, then the specified algorithms will be appended to the default set instead of replacing them. +If the specified value begins with a +.Sq - +character, then the specified algorithms (including wildcards) will be removed +from the default set instead of replacing them. .Pp The algorithms that contain .Qq -etm @@ -1264,6 +1284,10 @@ Alternately if the specified value begins with a .Sq + character, then the key types after it will be appended to the default instead of replacing it. +If the specified value begins with a +.Sq - +character, then the specified key types (including wildcards) will be removed +from the default set instead of replacing them. The default for this option is: .Bd -literal -offset 3n ecdsa-sha2-nistp256-cert-v01@openssh.com, diff --git a/sshd_config.5 b/sshd_config.5 index 935fda4b7..454e46e0b 100644 --- a/sshd_config.5 +++ b/sshd_config.5 @@ -33,8 +33,8 @@ .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. .\" -.\" $OpenBSD: sshd_config.5,v 1.241 2017/01/06 16:28:12 jmc Exp $ -.Dd $Mdocdate: January 6 2017 $ +.\" $OpenBSD: sshd_config.5,v 1.242 2017/02/03 23:01:19 djm Exp $ +.Dd $Mdocdate: February 3 2017 $ .Dt SSHD_CONFIG 5 .Os .Sh NAME @@ -437,6 +437,10 @@ If the specified value begins with a .Sq + character, then the specified ciphers will be appended to the default set instead of replacing them. +If the specified value begins with a +.Sq - +character, then the specified ciphers (including wildcards) will be removed +from the default set instead of replacing them. .Pp The supported ciphers are: .Pp @@ -649,6 +653,10 @@ Alternately if the specified value begins with a .Sq + character, then the specified key types will be appended to the default set instead of replacing them. +If the specified value begins with a +.Sq - +character, then the specified key types (including wildcards) will be removed +from the default set instead of replacing them. The default for this option is: .Bd -literal -offset 3n ecdsa-sha2-nistp256-cert-v01@openssh.com, @@ -843,6 +851,10 @@ Alternately if the specified value begins with a .Sq + character, then the specified methods will be appended to the default set instead of replacing them. +If the specified value begins with a +.Sq - +character, then the specified methods (including wildcards) will be removed +from the default set instead of replacing them. The supported algorithms are: .Pp .Bl -item -compact -offset indent @@ -933,6 +945,10 @@ If the specified value begins with a .Sq + character, then the specified algorithms will be appended to the default set instead of replacing them. +If the specified value begins with a +.Sq - +character, then the specified algorithms (including wildcards) will be removed +from the default set instead of replacing them. .Pp The algorithms that contain .Qq -etm @@ -1280,6 +1296,10 @@ Alternately if the specified value begins with a .Sq + character, then the specified key types will be appended to the default set instead of replacing them. +If the specified value begins with a +.Sq - +character, then the specified key types (including wildcards) will be removed +from the default set instead of replacing them. The default for this option is: .Bd -literal -offset 3n ecdsa-sha2-nistp256-cert-v01@openssh.com, -- cgit v1.2.3 From f6edbe9febff8121f26835996b1229b5064d31b7 Mon Sep 17 00:00:00 2001 From: "dtucker@openbsd.org" Date: Fri, 10 Mar 2017 03:24:48 +0000 Subject: upstream commit Plug mem leak on GLOB_NOMATCH case. From jjelen at redhat.com via bz#2687, ok djm@ Upstream-ID: 8016a7ae97719d3aa55fb723fc2ad3200058340d --- readconf.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'readconf.c') diff --git a/readconf.c b/readconf.c index e51481b10..c62c2eaba 100644 --- a/readconf.c +++ b/readconf.c @@ -1,4 +1,4 @@ -/* $OpenBSD: readconf.c,v 1.268 2017/02/03 23:01:19 djm Exp $ */ +/* $OpenBSD: readconf.c,v 1.269 2017/03/10 03:24:48 dtucker Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -1500,6 +1500,7 @@ parse_keytypes: if (r == GLOB_NOMATCH) { debug("%.200s line %d: include %s matched no " "files",filename, linenum, arg2); + free(arg2); continue; } else if (r != 0 || gl.gl_pathc < 0) fatal("%.200s line %d: glob failed for %s.", -- cgit v1.2.3 From 61b8ef6a66efaec07e023342cb94a10bdc2254dc Mon Sep 17 00:00:00 2001 From: "djm@openbsd.org" Date: Fri, 10 Mar 2017 04:27:32 +0000 Subject: upstream commit better match sshd config parser behaviour: fatal() if line is overlong, increase line buffer to match sshd's; bz#2651 reported by Don Fong; ok dtucker@ Upstream-ID: b175ae7e0ba403833f1ee566edf10f67443ccd18 --- readconf.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'readconf.c') diff --git a/readconf.c b/readconf.c index c62c2eaba..9d59493f0 100644 --- a/readconf.c +++ b/readconf.c @@ -1,4 +1,4 @@ -/* $OpenBSD: readconf.c,v 1.269 2017/03/10 03:24:48 dtucker Exp $ */ +/* $OpenBSD: readconf.c,v 1.270 2017/03/10 04:27:32 djm Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -1720,7 +1720,7 @@ read_config_file_depth(const char *filename, struct passwd *pw, int flags, int *activep, int depth) { FILE *f; - char line[1024]; + char line[4096]; int linenum; int bad_options = 0; @@ -1750,6 +1750,8 @@ read_config_file_depth(const char *filename, struct passwd *pw, while (fgets(line, sizeof(line), f)) { /* Update line number counter. */ linenum++; + if (strlen(line) == sizeof(line) - 1) + fatal("%s line %d too long", filename, linenum); if (process_config_line_depth(options, pw, host, original_host, line, filename, linenum, activep, flags, depth) != 0) bad_options++; -- cgit v1.2.3 From d51c7ac3328464dec21514fb398ab5c140a0664f Mon Sep 17 00:00:00 2001 From: Simon Wilkinson Date: Sun, 9 Feb 2014 16:09:48 +0000 Subject: GSSAPI key exchange support This patch has been rejected upstream: "None of the OpenSSH developers are in favour of adding this, and this situation has not changed for several years. This is not a slight on Simon's patch, which is of fine quality, but just that a) we don't trust GSSAPI implementations that much and b) we don't like adding new KEX since they are pre-auth attack surface. This one is particularly scary, since it requires hooks out to typically root-owned system resources." However, quite a lot of people rely on this in Debian, and it's better to have it merged into the main openssh package rather than having separate -krb5 packages (as we used to have). It seems to have a generally good security history. Bug: https://bugzilla.mindrot.org/show_bug.cgi?id=1242 Last-Updated: 2017-01-16 Patch-Name: gssapi.patch --- ChangeLog.gssapi | 113 +++++++++++++++++++ Makefile.in | 3 +- auth-krb5.c | 17 ++- auth.c | 96 +--------------- auth2-gss.c | 48 +++++++- auth2.c | 2 + canohost.c | 93 +++++++++++++++ canohost.h | 3 + clientloop.c | 15 ++- config.h.in | 6 + configure.ac | 24 ++++ gss-genr.c | 275 +++++++++++++++++++++++++++++++++++++++++++- gss-serv-krb5.c | 85 ++++++++++++-- gss-serv.c | 184 +++++++++++++++++++++++++++--- kex.c | 19 ++++ kex.h | 14 +++ kexgssc.c | 338 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ kexgsss.c | 295 ++++++++++++++++++++++++++++++++++++++++++++++++ monitor.c | 115 +++++++++++++++++-- monitor.h | 3 + monitor_wrap.c | 47 +++++++- monitor_wrap.h | 4 +- readconf.c | 43 +++++++ readconf.h | 5 + servconf.c | 26 +++++ servconf.h | 2 + ssh-gss.h | 41 ++++++- ssh_config | 2 + ssh_config.5 | 32 ++++++ sshconnect2.c | 131 ++++++++++++++++++++- sshd.c | 112 +++++++++++++++++- sshd_config | 2 + sshd_config.5 | 10 ++ sshkey.c | 3 +- sshkey.h | 1 + 35 files changed, 2062 insertions(+), 147 deletions(-) create mode 100644 ChangeLog.gssapi create mode 100644 kexgssc.c create mode 100644 kexgsss.c (limited to 'readconf.c') diff --git a/ChangeLog.gssapi b/ChangeLog.gssapi new file mode 100644 index 000000000..f117a336a --- /dev/null +++ b/ChangeLog.gssapi @@ -0,0 +1,113 @@ +20110101 + - Finally update for OpenSSH 5.6p1 + - Add GSSAPIServerIdentity option from Jim Basney + +20100308 + - [ Makefile.in, key.c, key.h ] + Updates for OpenSSH 5.4p1 + - [ servconf.c ] + Include GSSAPI options in the sshd -T configuration dump, and flag + some older configuration options as being unsupported. Thanks to Colin + Watson. + - + +20100124 + - [ sshconnect2.c ] + Adapt to deal with additional element in Authmethod structure. Thanks to + Colin Watson + +20090615 + - [ gss-genr.c gss-serv.c kexgssc.c kexgsss.c monitor.c sshconnect2.c + sshd.c ] + Fix issues identified by Greg Hudson following a code review + Check return value of gss_indicate_mechs + Protect GSSAPI calls in monitor, so they can only be used if enabled + Check return values of bignum functions in key exchange + Use BN_clear_free to clear other side's DH value + Make ssh_gssapi_id_kex more robust + Only configure kex table pointers if GSSAPI is enabled + Don't leak mechanism list, or gss mechanism list + Cast data.length before printing + If serverkey isn't provided, use an empty string, rather than NULL + +20090201 + - [ gss-genr.c gss-serv.c kex.h kexgssc.c readconf.c readconf.h ssh-gss.h + ssh_config.5 sshconnet2.c ] + Add support for the GSSAPIClientIdentity option, which allows the user + to specify which GSSAPI identity to use to contact a given server + +20080404 + - [ gss-serv.c ] + Add code to actually implement GSSAPIStrictAcceptCheck, which had somehow + been omitted from a previous version of this patch. Reported by Borislav + Stoichkov + +20070317 + - [ gss-serv-krb5.c ] + Remove C99ism, where new_ccname was being declared in the middle of a + function + +20061220 + - [ servconf.c ] + Make default for GSSAPIStrictAcceptorCheck be Yes, to match previous, and + documented, behaviour. Reported by Dan Watson. + +20060910 + - [ gss-genr.c kexgssc.c kexgsss.c kex.h monitor.c sshconnect2.c sshd.c + ssh-gss.h ] + add support for gss-group14-sha1 key exchange mechanisms + - [ gss-serv.c servconf.c servconf.h sshd_config sshd_config.5 ] + Add GSSAPIStrictAcceptorCheck option to allow the disabling of + acceptor principal checking on multi-homed machines. + + - [ sshd_config ssh_config ] + Add settings for GSSAPIKeyExchange and GSSAPITrustDNS to the sample + configuration files + - [ kexgss.c kegsss.c sshconnect2.c sshd.c ] + Code cleanup. Replace strlen/xmalloc/snprintf sequences with xasprintf() + Limit length of error messages displayed by client + +20060909 + - [ gss-genr.c gss-serv.c ] + move ssh_gssapi_acquire_cred() and ssh_gssapi_server_ctx to be server + only, where they belong + + +20060829 + - [ gss-serv-krb5.c ] + Fix CCAPI credentials cache name when creating KRB5CCNAME environment + variable + +20060828 + - [ gss-genr.c ] + Avoid Heimdal context freeing problem + + +20060818 + - [ gss-genr.c ssh-gss.h sshconnect2.c ] + Make sure that SPENGO is disabled + + +20060421 + - [ gssgenr.c, sshconnect2.c ] + a few type changes (signed versus unsigned, int versus size_t) to + fix compiler errors/warnings + (from jbasney AT ncsa.uiuc.edu) + - [ kexgssc.c, sshconnect2.c ] + fix uninitialized variable warnings + (from jbasney AT ncsa.uiuc.edu) + - [ gssgenr.c ] + pass oid to gss_display_status (helpful when using GSSAPI mechglue) + (from jbasney AT ncsa.uiuc.edu) + + - [ gss-serv-krb5.c ] + #ifdef HAVE_GSSAPI_KRB5 should be #ifdef HAVE_GSSAPI_KRB5_H + (from jbasney AT ncsa.uiuc.edu) + + - [ readconf.c, readconf.h, ssh_config.5, sshconnect2.c + add client-side GssapiKeyExchange option + (from jbasney AT ncsa.uiuc.edu) + - [ sshconnect2.c ] + add support for GssapiTrustDns option for gssapi-with-mic + (from jbasney AT ncsa.uiuc.edu) + diff --git a/Makefile.in b/Makefile.in index 5870e9e6e..6b774c1ab 100644 --- a/Makefile.in +++ b/Makefile.in @@ -92,6 +92,7 @@ LIBSSH_OBJS=${LIBOPENSSH_OBJS} \ kex.o kexdh.o kexgex.o kexecdh.o kexc25519.o \ kexdhc.o kexgexc.o kexecdhc.o kexc25519c.o \ kexdhs.o kexgexs.o kexecdhs.o kexc25519s.o \ + kexgssc.o \ platform-pledge.o platform-tracing.o SSHOBJS= ssh.o readconf.o clientloop.o sshtty.o \ @@ -105,7 +106,7 @@ SSHDOBJS=sshd.o auth-rhosts.o auth-passwd.o \ auth-skey.o auth-bsdauth.o auth2-hostbased.o auth2-kbdint.o \ auth2-none.o auth2-passwd.o auth2-pubkey.o \ monitor.o monitor_wrap.o auth-krb5.o \ - auth2-gss.o gss-serv.o gss-serv-krb5.o \ + auth2-gss.o gss-serv.o gss-serv-krb5.o kexgsss.o \ loginrec.o auth-pam.o auth-shadow.o auth-sia.o md5crypt.o \ sftp-server.o sftp-common.o \ sandbox-null.o sandbox-rlimit.o sandbox-systrace.o sandbox-darwin.o \ diff --git a/auth-krb5.c b/auth-krb5.c index a5a81ed2e..38e7fee21 100644 --- a/auth-krb5.c +++ b/auth-krb5.c @@ -182,8 +182,13 @@ auth_krb5_password(Authctxt *authctxt, const char *password) len = strlen(authctxt->krb5_ticket_file) + 6; authctxt->krb5_ccname = xmalloc(len); +#ifdef USE_CCAPI + snprintf(authctxt->krb5_ccname, len, "API:%s", + authctxt->krb5_ticket_file); +#else snprintf(authctxt->krb5_ccname, len, "FILE:%s", authctxt->krb5_ticket_file); +#endif #ifdef USE_PAM if (options.use_pam) @@ -240,15 +245,22 @@ krb5_cleanup_proc(Authctxt *authctxt) #ifndef HEIMDAL krb5_error_code ssh_krb5_cc_gen(krb5_context ctx, krb5_ccache *ccache) { - int tmpfd, ret, oerrno; + int ret, oerrno; char ccname[40]; mode_t old_umask; +#ifdef USE_CCAPI + char cctemplate[] = "API:krb5cc_%d"; +#else + char cctemplate[] = "FILE:/tmp/krb5cc_%d_XXXXXXXXXX"; + int tmpfd; +#endif ret = snprintf(ccname, sizeof(ccname), - "FILE:/tmp/krb5cc_%d_XXXXXXXXXX", geteuid()); + cctemplate, geteuid()); if (ret < 0 || (size_t)ret >= sizeof(ccname)) return ENOMEM; +#ifndef USE_CCAPI old_umask = umask(0177); tmpfd = mkstemp(ccname + strlen("FILE:")); oerrno = errno; @@ -265,6 +277,7 @@ ssh_krb5_cc_gen(krb5_context ctx, krb5_ccache *ccache) { return oerrno; } close(tmpfd); +#endif return (krb5_cc_resolve(ctx, ccname, ccache)); } diff --git a/auth.c b/auth.c index 6ee6116df..c63906873 100644 --- a/auth.c +++ b/auth.c @@ -372,7 +372,8 @@ auth_root_allowed(const char *method) case PERMIT_NO_PASSWD: if (strcmp(method, "publickey") == 0 || strcmp(method, "hostbased") == 0 || - strcmp(method, "gssapi-with-mic") == 0) + strcmp(method, "gssapi-with-mic") == 0 || + strcmp(method, "gssapi-keyex") == 0) return 1; break; case PERMIT_FORCED_ONLY: @@ -794,99 +795,6 @@ fakepw(void) return (&fake); } -/* - * Returns the remote DNS hostname as a string. The returned string must not - * be freed. NB. this will usually trigger a DNS query the first time it is - * called. - * This function does additional checks on the hostname to mitigate some - * attacks on legacy rhosts-style authentication. - * XXX is RhostsRSAAuthentication vulnerable to these? - * XXX Can we remove these checks? (or if not, remove RhostsRSAAuthentication?) - */ - -static char * -remote_hostname(struct ssh *ssh) -{ - struct sockaddr_storage from; - socklen_t fromlen; - struct addrinfo hints, *ai, *aitop; - char name[NI_MAXHOST], ntop2[NI_MAXHOST]; - const char *ntop = ssh_remote_ipaddr(ssh); - - /* Get IP address of client. */ - fromlen = sizeof(from); - memset(&from, 0, sizeof(from)); - if (getpeername(ssh_packet_get_connection_in(ssh), - (struct sockaddr *)&from, &fromlen) < 0) { - debug("getpeername failed: %.100s", strerror(errno)); - return strdup(ntop); - } - - ipv64_normalise_mapped(&from, &fromlen); - if (from.ss_family == AF_INET6) - fromlen = sizeof(struct sockaddr_in6); - - debug3("Trying to reverse map address %.100s.", ntop); - /* Map the IP address to a host name. */ - if (getnameinfo((struct sockaddr *)&from, fromlen, name, sizeof(name), - NULL, 0, NI_NAMEREQD) != 0) { - /* Host name not found. Use ip address. */ - return strdup(ntop); - } - - /* - * if reverse lookup result looks like a numeric hostname, - * someone is trying to trick us by PTR record like following: - * 1.1.1.10.in-addr.arpa. IN PTR 2.3.4.5 - */ - memset(&hints, 0, sizeof(hints)); - hints.ai_socktype = SOCK_DGRAM; /*dummy*/ - hints.ai_flags = AI_NUMERICHOST; - if (getaddrinfo(name, NULL, &hints, &ai) == 0) { - logit("Nasty PTR record \"%s\" is set up for %s, ignoring", - name, ntop); - freeaddrinfo(ai); - return strdup(ntop); - } - - /* Names are stored in lowercase. */ - lowercase(name); - - /* - * Map it back to an IP address and check that the given - * address actually is an address of this host. This is - * necessary because anyone with access to a name server can - * define arbitrary names for an IP address. Mapping from - * name to IP address can be trusted better (but can still be - * fooled if the intruder has access to the name server of - * the domain). - */ - memset(&hints, 0, sizeof(hints)); - hints.ai_family = from.ss_family; - hints.ai_socktype = SOCK_STREAM; - if (getaddrinfo(name, NULL, &hints, &aitop) != 0) { - logit("reverse mapping checking getaddrinfo for %.700s " - "[%s] failed.", name, ntop); - return strdup(ntop); - } - /* Look for the address from the list of addresses. */ - for (ai = aitop; ai; ai = ai->ai_next) { - if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop2, - sizeof(ntop2), NULL, 0, NI_NUMERICHOST) == 0 && - (strcmp(ntop, ntop2) == 0)) - break; - } - freeaddrinfo(aitop); - /* If we reached the end of the list, the address was not there. */ - if (ai == NULL) { - /* Address not found for the host name. */ - logit("Address %.100s maps to %.600s, but this does not " - "map back to the address.", ntop, name); - return strdup(ntop); - } - return strdup(name); -} - /* * Return the canonical name of the host in the other side of the current * connection. The host name is cached, so it is efficient to call this diff --git a/auth2-gss.c b/auth2-gss.c index 1ca835773..3b5036dfd 100644 --- a/auth2-gss.c +++ b/auth2-gss.c @@ -1,7 +1,7 @@ /* $OpenBSD: auth2-gss.c,v 1.22 2015/01/19 20:07:45 markus Exp $ */ /* - * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved. + * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -53,6 +53,40 @@ static int input_gssapi_mic(int type, u_int32_t plen, void *ctxt); static int input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt); static int input_gssapi_errtok(int, u_int32_t, void *); +/* + * The 'gssapi_keyex' userauth mechanism. + */ +static int +userauth_gsskeyex(Authctxt *authctxt) +{ + int authenticated = 0; + Buffer b; + gss_buffer_desc mic, gssbuf; + u_int len; + + mic.value = packet_get_string(&len); + mic.length = len; + + packet_check_eom(); + + ssh_gssapi_buildmic(&b, authctxt->user, authctxt->service, + "gssapi-keyex"); + + gssbuf.value = buffer_ptr(&b); + gssbuf.length = buffer_len(&b); + + /* gss_kex_context is NULL with privsep, so we can't check it here */ + if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gss_kex_context, + &gssbuf, &mic)))) + authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user, + authctxt->pw)); + + buffer_free(&b); + free(mic.value); + + return (authenticated); +} + /* * We only support those mechanisms that we know about (ie ones that we know * how to check local user kuserok and the like) @@ -238,7 +272,8 @@ input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt) packet_check_eom(); - authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user)); + authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user, + authctxt->pw)); authctxt->postponed = 0; dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL); @@ -274,7 +309,8 @@ input_gssapi_mic(int type, u_int32_t plen, void *ctxt) gssbuf.length = buffer_len(&b); if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic)))) - authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user)); + authenticated = + PRIVSEP(ssh_gssapi_userok(authctxt->user, authctxt->pw)); else logit("GSSAPI MIC check failed"); @@ -290,6 +326,12 @@ input_gssapi_mic(int type, u_int32_t plen, void *ctxt) return 0; } +Authmethod method_gsskeyex = { + "gssapi-keyex", + userauth_gsskeyex, + &options.gss_authentication +}; + Authmethod method_gssapi = { "gssapi-with-mic", userauth_gssapi, diff --git a/auth2.c b/auth2.c index 97dd2ef0a..946e92355 100644 --- a/auth2.c +++ b/auth2.c @@ -70,6 +70,7 @@ extern Authmethod method_passwd; extern Authmethod method_kbdint; extern Authmethod method_hostbased; #ifdef GSSAPI +extern Authmethod method_gsskeyex; extern Authmethod method_gssapi; #endif @@ -77,6 +78,7 @@ Authmethod *authmethods[] = { &method_none, &method_pubkey, #ifdef GSSAPI + &method_gsskeyex, &method_gssapi, #endif &method_passwd, diff --git a/canohost.c b/canohost.c index f71a08568..404731d24 100644 --- a/canohost.c +++ b/canohost.c @@ -35,6 +35,99 @@ #include "canohost.h" #include "misc.h" +/* + * Returns the remote DNS hostname as a string. The returned string must not + * be freed. NB. this will usually trigger a DNS query the first time it is + * called. + * This function does additional checks on the hostname to mitigate some + * attacks on legacy rhosts-style authentication. + * XXX is RhostsRSAAuthentication vulnerable to these? + * XXX Can we remove these checks? (or if not, remove RhostsRSAAuthentication?) + */ + +char * +remote_hostname(struct ssh *ssh) +{ + struct sockaddr_storage from; + socklen_t fromlen; + struct addrinfo hints, *ai, *aitop; + char name[NI_MAXHOST], ntop2[NI_MAXHOST]; + const char *ntop = ssh_remote_ipaddr(ssh); + + /* Get IP address of client. */ + fromlen = sizeof(from); + memset(&from, 0, sizeof(from)); + if (getpeername(ssh_packet_get_connection_in(ssh), + (struct sockaddr *)&from, &fromlen) < 0) { + debug("getpeername failed: %.100s", strerror(errno)); + return strdup(ntop); + } + + ipv64_normalise_mapped(&from, &fromlen); + if (from.ss_family == AF_INET6) + fromlen = sizeof(struct sockaddr_in6); + + debug3("Trying to reverse map address %.100s.", ntop); + /* Map the IP address to a host name. */ + if (getnameinfo((struct sockaddr *)&from, fromlen, name, sizeof(name), + NULL, 0, NI_NAMEREQD) != 0) { + /* Host name not found. Use ip address. */ + return strdup(ntop); + } + + /* + * if reverse lookup result looks like a numeric hostname, + * someone is trying to trick us by PTR record like following: + * 1.1.1.10.in-addr.arpa. IN PTR 2.3.4.5 + */ + memset(&hints, 0, sizeof(hints)); + hints.ai_socktype = SOCK_DGRAM; /*dummy*/ + hints.ai_flags = AI_NUMERICHOST; + if (getaddrinfo(name, NULL, &hints, &ai) == 0) { + logit("Nasty PTR record \"%s\" is set up for %s, ignoring", + name, ntop); + freeaddrinfo(ai); + return strdup(ntop); + } + + /* Names are stored in lowercase. */ + lowercase(name); + + /* + * Map it back to an IP address and check that the given + * address actually is an address of this host. This is + * necessary because anyone with access to a name server can + * define arbitrary names for an IP address. Mapping from + * name to IP address can be trusted better (but can still be + * fooled if the intruder has access to the name server of + * the domain). + */ + memset(&hints, 0, sizeof(hints)); + hints.ai_family = from.ss_family; + hints.ai_socktype = SOCK_STREAM; + if (getaddrinfo(name, NULL, &hints, &aitop) != 0) { + logit("reverse mapping checking getaddrinfo for %.700s " + "[%s] failed.", name, ntop); + return strdup(ntop); + } + /* Look for the address from the list of addresses. */ + for (ai = aitop; ai; ai = ai->ai_next) { + if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop2, + sizeof(ntop2), NULL, 0, NI_NUMERICHOST) == 0 && + (strcmp(ntop, ntop2) == 0)) + break; + } + freeaddrinfo(aitop); + /* If we reached the end of the list, the address was not there. */ + if (ai == NULL) { + /* Address not found for the host name. */ + logit("Address %.100s maps to %.600s, but this does not " + "map back to the address.", ntop, name); + return strdup(ntop); + } + return strdup(name); +} + void ipv64_normalise_mapped(struct sockaddr_storage *addr, socklen_t *len) { diff --git a/canohost.h b/canohost.h index 26d62855a..0cadc9f18 100644 --- a/canohost.h +++ b/canohost.h @@ -15,6 +15,9 @@ #ifndef _CANOHOST_H #define _CANOHOST_H +struct ssh; + +char *remote_hostname(struct ssh *); char *get_peer_ipaddr(int); int get_peer_port(int); char *get_local_ipaddr(int); diff --git a/clientloop.c b/clientloop.c index 064816234..38b0330e9 100644 --- a/clientloop.c +++ b/clientloop.c @@ -113,6 +113,10 @@ #include "ssherr.h" #include "hostfile.h" +#ifdef GSSAPI +#include "ssh-gss.h" +#endif + /* import options */ extern Options options; @@ -1664,9 +1668,18 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) break; /* Do channel operations unless rekeying in progress. */ - if (!ssh_packet_is_rekeying(active_state)) + if (!ssh_packet_is_rekeying(active_state)) { channel_after_select(readset, writeset); +#ifdef GSSAPI + if (options.gss_renewal_rekey && + ssh_gssapi_credentials_updated(NULL)) { + debug("credentials updated - forcing rekey"); + need_rekeying = 1; + } +#endif + } + /* Buffer input from the connection. */ client_process_net_input(readset); diff --git a/config.h.in b/config.h.in index b65420e4a..fd8a73f1b 100644 --- a/config.h.in +++ b/config.h.in @@ -1670,6 +1670,9 @@ /* Use btmp to log bad logins */ #undef USE_BTMP +/* platform uses an in-memory credentials cache */ +#undef USE_CCAPI + /* Use libedit for sftp */ #undef USE_LIBEDIT @@ -1685,6 +1688,9 @@ /* Use PIPES instead of a socketpair() */ #undef USE_PIPES +/* platform has the Security Authorization Session API */ +#undef USE_SECURITY_SESSION_API + /* Define if you have Solaris privileges */ #undef USE_SOLARIS_PRIVS diff --git a/configure.ac b/configure.ac index c2878e3d4..ead34acf5 100644 --- a/configure.ac +++ b/configure.ac @@ -623,6 +623,30 @@ main() { if (NSVersionOfRunTimeLibrary("System") >= (60 << 16)) [Use tunnel device compatibility to OpenBSD]) AC_DEFINE([SSH_TUN_PREPEND_AF], [1], [Prepend the address family to IP tunnel traffic]) + AC_MSG_CHECKING([if we have the Security Authorization Session API]) + AC_TRY_COMPILE([#include ], + [SessionCreate(0, 0);], + [ac_cv_use_security_session_api="yes" + AC_DEFINE([USE_SECURITY_SESSION_API], [1], + [platform has the Security Authorization Session API]) + LIBS="$LIBS -framework Security" + AC_MSG_RESULT([yes])], + [ac_cv_use_security_session_api="no" + AC_MSG_RESULT([no])]) + AC_MSG_CHECKING([if we have an in-memory credentials cache]) + AC_TRY_COMPILE( + [#include ], + [cc_context_t c; + (void) cc_initialize (&c, 0, NULL, NULL);], + [AC_DEFINE([USE_CCAPI], [1], + [platform uses an in-memory credentials cache]) + LIBS="$LIBS -framework Security" + AC_MSG_RESULT([yes]) + if test "x$ac_cv_use_security_session_api" = "xno"; then + AC_MSG_ERROR([*** Need a security framework to use the credentials cache API ***]) + fi], + [AC_MSG_RESULT([no])] + ) m4_pattern_allow([AU_IPv]) AC_CHECK_DECL([AU_IPv4], [], AC_DEFINE([AU_IPv4], [0], [System only supports IPv4 audit records]) diff --git a/gss-genr.c b/gss-genr.c index 62559ed9e..0b3ae073c 100644 --- a/gss-genr.c +++ b/gss-genr.c @@ -1,7 +1,7 @@ /* $OpenBSD: gss-genr.c,v 1.24 2016/09/12 01:22:38 deraadt Exp $ */ /* - * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved. + * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -40,12 +40,167 @@ #include "buffer.h" #include "log.h" #include "ssh2.h" +#include "cipher.h" +#include "key.h" +#include "kex.h" +#include #include "ssh-gss.h" extern u_char *session_id2; extern u_int session_id2_len; +typedef struct { + char *encoded; + gss_OID oid; +} ssh_gss_kex_mapping; + +/* + * XXX - It would be nice to find a more elegant way of handling the + * XXX passing of the key exchange context to the userauth routines + */ + +Gssctxt *gss_kex_context = NULL; + +static ssh_gss_kex_mapping *gss_enc2oid = NULL; + +int +ssh_gssapi_oid_table_ok(void) { + return (gss_enc2oid != NULL); +} + +/* + * Return a list of the gss-group1-sha1 mechanisms supported by this program + * + * We test mechanisms to ensure that we can use them, to avoid starting + * a key exchange with a bad mechanism + */ + +char * +ssh_gssapi_client_mechanisms(const char *host, const char *client) { + gss_OID_set gss_supported; + OM_uint32 min_status; + + if (GSS_ERROR(gss_indicate_mechs(&min_status, &gss_supported))) + return NULL; + + return(ssh_gssapi_kex_mechs(gss_supported, ssh_gssapi_check_mechanism, + host, client)); +} + +char * +ssh_gssapi_kex_mechs(gss_OID_set gss_supported, ssh_gssapi_check_fn *check, + const char *host, const char *client) { + Buffer buf; + size_t i; + int oidpos, enclen; + char *mechs, *encoded; + u_char digest[EVP_MAX_MD_SIZE]; + char deroid[2]; + const EVP_MD *evp_md = EVP_md5(); + EVP_MD_CTX md; + + if (gss_enc2oid != NULL) { + for (i = 0; gss_enc2oid[i].encoded != NULL; i++) + free(gss_enc2oid[i].encoded); + free(gss_enc2oid); + } + + gss_enc2oid = xmalloc(sizeof(ssh_gss_kex_mapping) * + (gss_supported->count + 1)); + + buffer_init(&buf); + + oidpos = 0; + for (i = 0; i < gss_supported->count; i++) { + if (gss_supported->elements[i].length < 128 && + (*check)(NULL, &(gss_supported->elements[i]), host, client)) { + + deroid[0] = SSH_GSS_OIDTYPE; + deroid[1] = gss_supported->elements[i].length; + + EVP_DigestInit(&md, evp_md); + EVP_DigestUpdate(&md, deroid, 2); + EVP_DigestUpdate(&md, + gss_supported->elements[i].elements, + gss_supported->elements[i].length); + EVP_DigestFinal(&md, digest, NULL); + + encoded = xmalloc(EVP_MD_size(evp_md) * 2); + enclen = __b64_ntop(digest, EVP_MD_size(evp_md), + encoded, EVP_MD_size(evp_md) * 2); + + if (oidpos != 0) + buffer_put_char(&buf, ','); + + buffer_append(&buf, KEX_GSS_GEX_SHA1_ID, + sizeof(KEX_GSS_GEX_SHA1_ID) - 1); + buffer_append(&buf, encoded, enclen); + buffer_put_char(&buf, ','); + buffer_append(&buf, KEX_GSS_GRP1_SHA1_ID, + sizeof(KEX_GSS_GRP1_SHA1_ID) - 1); + buffer_append(&buf, encoded, enclen); + buffer_put_char(&buf, ','); + buffer_append(&buf, KEX_GSS_GRP14_SHA1_ID, + sizeof(KEX_GSS_GRP14_SHA1_ID) - 1); + buffer_append(&buf, encoded, enclen); + + gss_enc2oid[oidpos].oid = &(gss_supported->elements[i]); + gss_enc2oid[oidpos].encoded = encoded; + oidpos++; + } + } + gss_enc2oid[oidpos].oid = NULL; + gss_enc2oid[oidpos].encoded = NULL; + + buffer_put_char(&buf, '\0'); + + mechs = xmalloc(buffer_len(&buf)); + buffer_get(&buf, mechs, buffer_len(&buf)); + buffer_free(&buf); + + if (strlen(mechs) == 0) { + free(mechs); + mechs = NULL; + } + + return (mechs); +} + +gss_OID +ssh_gssapi_id_kex(Gssctxt *ctx, char *name, int kex_type) { + int i = 0; + + switch (kex_type) { + case KEX_GSS_GRP1_SHA1: + if (strlen(name) < sizeof(KEX_GSS_GRP1_SHA1_ID)) + return GSS_C_NO_OID; + name += sizeof(KEX_GSS_GRP1_SHA1_ID) - 1; + break; + case KEX_GSS_GRP14_SHA1: + if (strlen(name) < sizeof(KEX_GSS_GRP14_SHA1_ID)) + return GSS_C_NO_OID; + name += sizeof(KEX_GSS_GRP14_SHA1_ID) - 1; + break; + case KEX_GSS_GEX_SHA1: + if (strlen(name) < sizeof(KEX_GSS_GEX_SHA1_ID)) + return GSS_C_NO_OID; + name += sizeof(KEX_GSS_GEX_SHA1_ID) - 1; + break; + default: + return GSS_C_NO_OID; + } + + while (gss_enc2oid[i].encoded != NULL && + strcmp(name, gss_enc2oid[i].encoded) != 0) + i++; + + if (gss_enc2oid[i].oid != NULL && ctx != NULL) + ssh_gssapi_set_oid(ctx, gss_enc2oid[i].oid); + + return gss_enc2oid[i].oid; +} + /* Check that the OID in a data stream matches that in the context */ int ssh_gssapi_check_oid(Gssctxt *ctx, void *data, size_t len) @@ -198,7 +353,7 @@ ssh_gssapi_init_ctx(Gssctxt *ctx, int deleg_creds, gss_buffer_desc *recv_tok, } ctx->major = gss_init_sec_context(&ctx->minor, - GSS_C_NO_CREDENTIAL, &ctx->context, ctx->name, ctx->oid, + ctx->client_creds, &ctx->context, ctx->name, ctx->oid, GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG | deleg_flag, 0, NULL, recv_tok, NULL, send_tok, flags, NULL); @@ -227,9 +382,43 @@ ssh_gssapi_import_name(Gssctxt *ctx, const char *host) return (ctx->major); } +OM_uint32 +ssh_gssapi_client_identity(Gssctxt *ctx, const char *name) +{ + gss_buffer_desc gssbuf; + gss_name_t gssname; + OM_uint32 status; + gss_OID_set oidset; + + gssbuf.value = (void *) name; + gssbuf.length = strlen(gssbuf.value); + + gss_create_empty_oid_set(&status, &oidset); + gss_add_oid_set_member(&status, ctx->oid, &oidset); + + ctx->major = gss_import_name(&ctx->minor, &gssbuf, + GSS_C_NT_USER_NAME, &gssname); + + if (!ctx->major) + ctx->major = gss_acquire_cred(&ctx->minor, + gssname, 0, oidset, GSS_C_INITIATE, + &ctx->client_creds, NULL, NULL); + + gss_release_name(&status, &gssname); + gss_release_oid_set(&status, &oidset); + + if (ctx->major) + ssh_gssapi_error(ctx); + + return(ctx->major); +} + OM_uint32 ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash) { + if (ctx == NULL) + return -1; + if ((ctx->major = gss_get_mic(&ctx->minor, ctx->context, GSS_C_QOP_DEFAULT, buffer, hash))) ssh_gssapi_error(ctx); @@ -237,6 +426,19 @@ ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash) return (ctx->major); } +/* Priviledged when used by server */ +OM_uint32 +ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic) +{ + if (ctx == NULL) + return -1; + + ctx->major = gss_verify_mic(&ctx->minor, ctx->context, + gssbuf, gssmic, NULL); + + return (ctx->major); +} + void ssh_gssapi_buildmic(Buffer *b, const char *user, const char *service, const char *context) @@ -250,11 +452,16 @@ ssh_gssapi_buildmic(Buffer *b, const char *user, const char *service, } int -ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host) +ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host, + const char *client) { gss_buffer_desc token = GSS_C_EMPTY_BUFFER; OM_uint32 major, minor; gss_OID_desc spnego_oid = {6, (void *)"\x2B\x06\x01\x05\x05\x02"}; + Gssctxt *intctx = NULL; + + if (ctx == NULL) + ctx = &intctx; /* RFC 4462 says we MUST NOT do SPNEGO */ if (oid->length == spnego_oid.length && @@ -264,6 +471,10 @@ ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host) ssh_gssapi_build_ctx(ctx); ssh_gssapi_set_oid(*ctx, oid); major = ssh_gssapi_import_name(*ctx, host); + + if (!GSS_ERROR(major) && client) + major = ssh_gssapi_client_identity(*ctx, client); + if (!GSS_ERROR(major)) { major = ssh_gssapi_init_ctx(*ctx, 0, GSS_C_NO_BUFFER, &token, NULL); @@ -273,10 +484,66 @@ ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host) GSS_C_NO_BUFFER); } - if (GSS_ERROR(major)) + if (GSS_ERROR(major) || intctx != NULL) ssh_gssapi_delete_ctx(ctx); return (!GSS_ERROR(major)); } +int +ssh_gssapi_credentials_updated(Gssctxt *ctxt) { + static gss_name_t saved_name = GSS_C_NO_NAME; + static OM_uint32 saved_lifetime = 0; + static gss_OID saved_mech = GSS_C_NO_OID; + static gss_name_t name; + static OM_uint32 last_call = 0; + OM_uint32 lifetime, now, major, minor; + int equal; + + now = time(NULL); + + if (ctxt) { + debug("Rekey has happened - updating saved versions"); + + if (saved_name != GSS_C_NO_NAME) + gss_release_name(&minor, &saved_name); + + major = gss_inquire_cred(&minor, GSS_C_NO_CREDENTIAL, + &saved_name, &saved_lifetime, NULL, NULL); + + if (!GSS_ERROR(major)) { + saved_mech = ctxt->oid; + saved_lifetime+= now; + } else { + /* Handle the error */ + } + return 0; + } + + if (now - last_call < 10) + return 0; + + last_call = now; + + if (saved_mech == GSS_C_NO_OID) + return 0; + + major = gss_inquire_cred(&minor, GSS_C_NO_CREDENTIAL, + &name, &lifetime, NULL, NULL); + if (major == GSS_S_CREDENTIALS_EXPIRED) + return 0; + else if (GSS_ERROR(major)) + return 0; + + major = gss_compare_name(&minor, saved_name, name, &equal); + gss_release_name(&minor, &name); + if (GSS_ERROR(major)) + return 0; + + if (equal && (saved_lifetime < lifetime + now - 10)) + return 1; + + return 0; +} + #endif /* GSSAPI */ diff --git a/gss-serv-krb5.c b/gss-serv-krb5.c index 795992d9f..fd8b37183 100644 --- a/gss-serv-krb5.c +++ b/gss-serv-krb5.c @@ -1,7 +1,7 @@ /* $OpenBSD: gss-serv-krb5.c,v 1.8 2013/07/20 01:55:13 djm Exp $ */ /* - * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved. + * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -121,8 +121,8 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_client *client) krb5_error_code problem; krb5_principal princ; OM_uint32 maj_status, min_status; - int len; const char *errmsg; + const char *new_ccname; if (client->creds == NULL) { debug("No credentials stored"); @@ -181,11 +181,16 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_client *client) return; } - client->store.filename = xstrdup(krb5_cc_get_name(krb_context, ccache)); + new_ccname = krb5_cc_get_name(krb_context, ccache); + client->store.envvar = "KRB5CCNAME"; - len = strlen(client->store.filename) + 6; - client->store.envval = xmalloc(len); - snprintf(client->store.envval, len, "FILE:%s", client->store.filename); +#ifdef USE_CCAPI + xasprintf(&client->store.envval, "API:%s", new_ccname); + client->store.filename = NULL; +#else + xasprintf(&client->store.envval, "FILE:%s", new_ccname); + client->store.filename = xstrdup(new_ccname); +#endif #ifdef USE_PAM if (options.use_pam) @@ -197,6 +202,71 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_client *client) return; } +int +ssh_gssapi_krb5_updatecreds(ssh_gssapi_ccache *store, + ssh_gssapi_client *client) +{ + krb5_ccache ccache = NULL; + krb5_principal principal = NULL; + char *name = NULL; + krb5_error_code problem; + OM_uint32 maj_status, min_status; + + if ((problem = krb5_cc_resolve(krb_context, store->envval, &ccache))) { + logit("krb5_cc_resolve(): %.100s", + krb5_get_err_text(krb_context, problem)); + return 0; + } + + /* Find out who the principal in this cache is */ + if ((problem = krb5_cc_get_principal(krb_context, ccache, + &principal))) { + logit("krb5_cc_get_principal(): %.100s", + krb5_get_err_text(krb_context, problem)); + krb5_cc_close(krb_context, ccache); + return 0; + } + + if ((problem = krb5_unparse_name(krb_context, principal, &name))) { + logit("krb5_unparse_name(): %.100s", + krb5_get_err_text(krb_context, problem)); + krb5_free_principal(krb_context, principal); + krb5_cc_close(krb_context, ccache); + return 0; + } + + + if (strcmp(name,client->exportedname.value)!=0) { + debug("Name in local credentials cache differs. Not storing"); + krb5_free_principal(krb_context, principal); + krb5_cc_close(krb_context, ccache); + krb5_free_unparsed_name(krb_context, name); + return 0; + } + krb5_free_unparsed_name(krb_context, name); + + /* Name matches, so lets get on with it! */ + + if ((problem = krb5_cc_initialize(krb_context, ccache, principal))) { + logit("krb5_cc_initialize(): %.100s", + krb5_get_err_text(krb_context, problem)); + krb5_free_principal(krb_context, principal); + krb5_cc_close(krb_context, ccache); + return 0; + } + + krb5_free_principal(krb_context, principal); + + if ((maj_status = gss_krb5_copy_ccache(&min_status, client->creds, + ccache))) { + logit("gss_krb5_copy_ccache() failed. Sorry!"); + krb5_cc_close(krb_context, ccache); + return 0; + } + + return 1; +} + ssh_gssapi_mech gssapi_kerberos_mech = { "toWM5Slw5Ew8Mqkay+al2g==", "Kerberos", @@ -204,7 +274,8 @@ ssh_gssapi_mech gssapi_kerberos_mech = { NULL, &ssh_gssapi_krb5_userok, NULL, - &ssh_gssapi_krb5_storecreds + &ssh_gssapi_krb5_storecreds, + &ssh_gssapi_krb5_updatecreds }; #endif /* KRB5 */ diff --git a/gss-serv.c b/gss-serv.c index 53993d674..2e27cbf9c 100644 --- a/gss-serv.c +++ b/gss-serv.c @@ -1,7 +1,7 @@ /* $OpenBSD: gss-serv.c,v 1.29 2015/05/22 03:50:02 djm Exp $ */ /* - * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved. + * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -45,17 +45,22 @@ #include "session.h" #include "misc.h" #include "servconf.h" +#include "uidswap.h" #include "ssh-gss.h" +#include "monitor_wrap.h" + +extern ServerOptions options; extern ServerOptions options; static ssh_gssapi_client gssapi_client = { GSS_C_EMPTY_BUFFER, GSS_C_EMPTY_BUFFER, - GSS_C_NO_CREDENTIAL, NULL, {NULL, NULL, NULL, NULL}}; + GSS_C_NO_CREDENTIAL, GSS_C_NO_NAME, NULL, + {NULL, NULL, NULL, NULL, NULL}, 0, 0}; ssh_gssapi_mech gssapi_null_mech = - { NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL}; + { NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL, NULL}; #ifdef KRB5 extern ssh_gssapi_mech gssapi_kerberos_mech; @@ -141,6 +146,28 @@ ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID oid) return (ssh_gssapi_acquire_cred(*ctx)); } +/* Unprivileged */ +char * +ssh_gssapi_server_mechanisms(void) { + if (supported_oids == NULL) + ssh_gssapi_prepare_supported_oids(); + return (ssh_gssapi_kex_mechs(supported_oids, + &ssh_gssapi_server_check_mech, NULL, NULL)); +} + +/* Unprivileged */ +int +ssh_gssapi_server_check_mech(Gssctxt **dum, gss_OID oid, const char *data, + const char *dummy) { + Gssctxt *ctx = NULL; + int res; + + res = !GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctx, oid))); + ssh_gssapi_delete_ctx(&ctx); + + return (res); +} + /* Unprivileged */ void ssh_gssapi_supported_oids(gss_OID_set *oidset) @@ -151,7 +178,9 @@ ssh_gssapi_supported_oids(gss_OID_set *oidset) gss_OID_set supported; gss_create_empty_oid_set(&min_status, oidset); - gss_indicate_mechs(&min_status, &supported); + + if (GSS_ERROR(gss_indicate_mechs(&min_status, &supported))) + return; while (supported_mechs[i]->name != NULL) { if (GSS_ERROR(gss_test_oid_set_member(&min_status, @@ -277,8 +306,48 @@ OM_uint32 ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client) { int i = 0; + int equal = 0; + gss_name_t new_name = GSS_C_NO_NAME; + gss_buffer_desc ename = GSS_C_EMPTY_BUFFER; + + if (options.gss_store_rekey && client->used && ctx->client_creds) { + if (client->mech->oid.length != ctx->oid->length || + (memcmp(client->mech->oid.elements, + ctx->oid->elements, ctx->oid->length) !=0)) { + debug("Rekeyed credentials have different mechanism"); + return GSS_S_COMPLETE; + } + + if ((ctx->major = gss_inquire_cred_by_mech(&ctx->minor, + ctx->client_creds, ctx->oid, &new_name, + NULL, NULL, NULL))) { + ssh_gssapi_error(ctx); + return (ctx->major); + } + + ctx->major = gss_compare_name(&ctx->minor, client->name, + new_name, &equal); + + if (GSS_ERROR(ctx->major)) { + ssh_gssapi_error(ctx); + return (ctx->major); + } + + if (!equal) { + debug("Rekeyed credentials have different name"); + return GSS_S_COMPLETE; + } - gss_buffer_desc ename; + debug("Marking rekeyed credentials for export"); + + gss_release_name(&ctx->minor, &client->name); + gss_release_cred(&ctx->minor, &client->creds); + client->name = new_name; + client->creds = ctx->client_creds; + ctx->client_creds = GSS_C_NO_CREDENTIAL; + client->updated = 1; + return GSS_S_COMPLETE; + } client->mech = NULL; @@ -293,6 +362,13 @@ ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client) if (client->mech == NULL) return GSS_S_FAILURE; + if (ctx->client_creds && + (ctx->major = gss_inquire_cred_by_mech(&ctx->minor, + ctx->client_creds, ctx->oid, &client->name, NULL, NULL, NULL))) { + ssh_gssapi_error(ctx); + return (ctx->major); + } + if ((ctx->major = gss_display_name(&ctx->minor, ctx->client, &client->displayname, NULL))) { ssh_gssapi_error(ctx); @@ -310,6 +386,8 @@ ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client) return (ctx->major); } + gss_release_buffer(&ctx->minor, &ename); + /* We can't copy this structure, so we just move the pointer to it */ client->creds = ctx->client_creds; ctx->client_creds = GSS_C_NO_CREDENTIAL; @@ -357,7 +435,7 @@ ssh_gssapi_do_child(char ***envp, u_int *envsizep) /* Privileged */ int -ssh_gssapi_userok(char *user) +ssh_gssapi_userok(char *user, struct passwd *pw) { OM_uint32 lmin; @@ -367,9 +445,11 @@ ssh_gssapi_userok(char *user) return 0; } if (gssapi_client.mech && gssapi_client.mech->userok) - if ((*gssapi_client.mech->userok)(&gssapi_client, user)) + if ((*gssapi_client.mech->userok)(&gssapi_client, user)) { + gssapi_client.used = 1; + gssapi_client.store.owner = pw; return 1; - else { + } else { /* Destroy delegated credentials if userok fails */ gss_release_buffer(&lmin, &gssapi_client.displayname); gss_release_buffer(&lmin, &gssapi_client.exportedname); @@ -383,14 +463,90 @@ ssh_gssapi_userok(char *user) return (0); } -/* Privileged */ -OM_uint32 -ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic) +/* These bits are only used for rekeying. The unpriviledged child is running + * as the user, the monitor is root. + * + * In the child, we want to : + * *) Ask the monitor to store our credentials into the store we specify + * *) If it succeeds, maybe do a PAM update + */ + +/* Stuff for PAM */ + +#ifdef USE_PAM +static int ssh_gssapi_simple_conv(int n, const struct pam_message **msg, + struct pam_response **resp, void *data) { - ctx->major = gss_verify_mic(&ctx->minor, ctx->context, - gssbuf, gssmic, NULL); + return (PAM_CONV_ERR); +} +#endif - return (ctx->major); +void +ssh_gssapi_rekey_creds(void) { + int ok; + int ret; +#ifdef USE_PAM + pam_handle_t *pamh = NULL; + struct pam_conv pamconv = {ssh_gssapi_simple_conv, NULL}; + char *envstr; +#endif + + if (gssapi_client.store.filename == NULL && + gssapi_client.store.envval == NULL && + gssapi_client.store.envvar == NULL) + return; + + ok = PRIVSEP(ssh_gssapi_update_creds(&gssapi_client.store)); + + if (!ok) + return; + + debug("Rekeyed credentials stored successfully"); + + /* Actually managing to play with the ssh pam stack from here will + * be next to impossible. In any case, we may want different options + * for rekeying. So, use our own :) + */ +#ifdef USE_PAM + if (!use_privsep) { + debug("Not even going to try and do PAM with privsep disabled"); + return; + } + + ret = pam_start("sshd-rekey", gssapi_client.store.owner->pw_name, + &pamconv, &pamh); + if (ret) + return; + + xasprintf(&envstr, "%s=%s", gssapi_client.store.envvar, + gssapi_client.store.envval); + + ret = pam_putenv(pamh, envstr); + if (!ret) + pam_setcred(pamh, PAM_REINITIALIZE_CRED); + pam_end(pamh, PAM_SUCCESS); +#endif +} + +int +ssh_gssapi_update_creds(ssh_gssapi_ccache *store) { + int ok = 0; + + /* Check we've got credentials to store */ + if (!gssapi_client.updated) + return 0; + + gssapi_client.updated = 0; + + temporarily_use_uid(gssapi_client.store.owner); + if (gssapi_client.mech && gssapi_client.mech->updatecreds) + ok = (*gssapi_client.mech->updatecreds)(store, &gssapi_client); + else + debug("No update function for this mechanism"); + + restore_uid(); + + return ok; } #endif diff --git a/kex.c b/kex.c index cf4ac0dc5..556a32e98 100644 --- a/kex.c +++ b/kex.c @@ -54,6 +54,10 @@ #include "sshbuf.h" #include "digest.h" +#ifdef GSSAPI +#include "ssh-gss.h" +#endif + #if OPENSSL_VERSION_NUMBER >= 0x00907000L # if defined(HAVE_EVP_SHA256) # define evp_ssh_sha256 EVP_sha256 @@ -113,6 +117,14 @@ static const struct kexalg kexalgs[] = { #endif /* HAVE_EVP_SHA256 || !WITH_OPENSSL */ { NULL, -1, -1, -1}, }; +static const struct kexalg kexalg_prefixes[] = { +#ifdef GSSAPI + { KEX_GSS_GEX_SHA1_ID, KEX_GSS_GEX_SHA1, 0, SSH_DIGEST_SHA1 }, + { KEX_GSS_GRP1_SHA1_ID, KEX_GSS_GRP1_SHA1, 0, SSH_DIGEST_SHA1 }, + { KEX_GSS_GRP14_SHA1_ID, KEX_GSS_GRP14_SHA1, 0, SSH_DIGEST_SHA1 }, +#endif + { NULL, -1, -1, -1 }, +}; char * kex_alg_list(char sep) @@ -145,6 +157,10 @@ kex_alg_by_name(const char *name) if (strcmp(k->name, name) == 0) return k; } + for (k = kexalg_prefixes; k->name != NULL; k++) { + if (strncmp(k->name, name, strlen(k->name)) == 0) + return k; + } return NULL; } @@ -605,6 +621,9 @@ kex_free(struct kex *kex) sshbuf_free(kex->peer); sshbuf_free(kex->my); free(kex->session_id); +#ifdef GSSAPI + free(kex->gss_host); +#endif /* GSSAPI */ free(kex->client_version_string); free(kex->server_version_string); free(kex->failed_choice); diff --git a/kex.h b/kex.h index 3794f2127..fd56171d2 100644 --- a/kex.h +++ b/kex.h @@ -99,6 +99,9 @@ enum kex_exchange { KEX_DH_GEX_SHA256, KEX_ECDH_SHA2, KEX_C25519_SHA256, + KEX_GSS_GRP1_SHA1, + KEX_GSS_GRP14_SHA1, + KEX_GSS_GEX_SHA1, KEX_MAX }; @@ -147,6 +150,12 @@ struct kex { u_int flags; int hash_alg; int ec_nid; +#ifdef GSSAPI + int gss_deleg_creds; + int gss_trust_dns; + char *gss_host; + char *gss_client; +#endif char *client_version_string; char *server_version_string; char *failed_choice; @@ -197,6 +206,11 @@ int kexecdh_server(struct ssh *); int kexc25519_client(struct ssh *); int kexc25519_server(struct ssh *); +#ifdef GSSAPI +int kexgss_client(struct ssh *); +int kexgss_server(struct ssh *); +#endif + int kex_dh_hash(int, const char *, const char *, const u_char *, size_t, const u_char *, size_t, const u_char *, size_t, const BIGNUM *, const BIGNUM *, const BIGNUM *, u_char *, size_t *); diff --git a/kexgssc.c b/kexgssc.c new file mode 100644 index 000000000..10447f2b0 --- /dev/null +++ b/kexgssc.c @@ -0,0 +1,338 @@ +/* + * Copyright (c) 2001-2009 Simon Wilkinson. 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. + * + * 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" + +#ifdef GSSAPI + +#include "includes.h" + +#include +#include + +#include + +#include "xmalloc.h" +#include "buffer.h" +#include "ssh2.h" +#include "key.h" +#include "cipher.h" +#include "kex.h" +#include "log.h" +#include "packet.h" +#include "dh.h" +#include "digest.h" + +#include "ssh-gss.h" + +int +kexgss_client(struct ssh *ssh) { + gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; + gss_buffer_desc recv_tok, gssbuf, msg_tok, *token_ptr; + Gssctxt *ctxt; + OM_uint32 maj_status, min_status, ret_flags; + u_int klen, kout, slen = 0, strlen; + DH *dh; + BIGNUM *dh_server_pub = NULL; + BIGNUM *shared_secret = NULL; + BIGNUM *p = NULL; + BIGNUM *g = NULL; + u_char *kbuf; + u_char *serverhostkey = NULL; + u_char *empty = ""; + char *msg; + int type = 0; + int first = 1; + int nbits = 0, min = DH_GRP_MIN, max = DH_GRP_MAX; + u_char hash[SSH_DIGEST_MAX_LENGTH]; + size_t hashlen; + + /* Initialise our GSSAPI world */ + ssh_gssapi_build_ctx(&ctxt); + if (ssh_gssapi_id_kex(ctxt, ssh->kex->name, ssh->kex->kex_type) + == GSS_C_NO_OID) + fatal("Couldn't identify host exchange"); + + if (ssh_gssapi_import_name(ctxt, ssh->kex->gss_host)) + fatal("Couldn't import hostname"); + + if (ssh->kex->gss_client && + ssh_gssapi_client_identity(ctxt, ssh->kex->gss_client)) + fatal("Couldn't acquire client credentials"); + + switch (ssh->kex->kex_type) { + case KEX_GSS_GRP1_SHA1: + dh = dh_new_group1(); + break; + case KEX_GSS_GRP14_SHA1: + dh = dh_new_group14(); + break; + case KEX_GSS_GEX_SHA1: + debug("Doing group exchange\n"); + nbits = dh_estimate(ssh->kex->we_need * 8); + packet_start(SSH2_MSG_KEXGSS_GROUPREQ); + packet_put_int(min); + packet_put_int(nbits); + packet_put_int(max); + + packet_send(); + + packet_read_expect(SSH2_MSG_KEXGSS_GROUP); + + if ((p = BN_new()) == NULL) + fatal("BN_new() failed"); + packet_get_bignum2(p); + if ((g = BN_new()) == NULL) + fatal("BN_new() failed"); + packet_get_bignum2(g); + packet_check_eom(); + + if (BN_num_bits(p) < min || BN_num_bits(p) > max) + fatal("GSSGRP_GEX group out of range: %d !< %d !< %d", + min, BN_num_bits(p), max); + + dh = dh_new_group(g, p); + break; + default: + fatal("%s: Unexpected KEX type %d", __func__, ssh->kex->kex_type); + } + + /* Step 1 - e is dh->pub_key */ + dh_gen_key(dh, ssh->kex->we_need * 8); + + /* This is f, we initialise it now to make life easier */ + dh_server_pub = BN_new(); + if (dh_server_pub == NULL) + fatal("dh_server_pub == NULL"); + + token_ptr = GSS_C_NO_BUFFER; + + do { + debug("Calling gss_init_sec_context"); + + maj_status = ssh_gssapi_init_ctx(ctxt, + ssh->kex->gss_deleg_creds, token_ptr, &send_tok, + &ret_flags); + + if (GSS_ERROR(maj_status)) { + if (send_tok.length != 0) { + packet_start(SSH2_MSG_KEXGSS_CONTINUE); + packet_put_string(send_tok.value, + send_tok.length); + } + fatal("gss_init_context failed"); + } + + /* If we've got an old receive buffer get rid of it */ + if (token_ptr != GSS_C_NO_BUFFER) + free(recv_tok.value); + + if (maj_status == GSS_S_COMPLETE) { + /* If mutual state flag is not true, kex fails */ + if (!(ret_flags & GSS_C_MUTUAL_FLAG)) + fatal("Mutual authentication failed"); + + /* If integ avail flag is not true kex fails */ + if (!(ret_flags & GSS_C_INTEG_FLAG)) + fatal("Integrity check failed"); + } + + /* + * If we have data to send, then the last message that we + * received cannot have been a 'complete'. + */ + if (send_tok.length != 0) { + if (first) { + packet_start(SSH2_MSG_KEXGSS_INIT); + packet_put_string(send_tok.value, + send_tok.length); + packet_put_bignum2(dh->pub_key); + first = 0; + } else { + packet_start(SSH2_MSG_KEXGSS_CONTINUE); + packet_put_string(send_tok.value, + send_tok.length); + } + packet_send(); + gss_release_buffer(&min_status, &send_tok); + + /* If we've sent them data, they should reply */ + do { + type = packet_read(); + if (type == SSH2_MSG_KEXGSS_HOSTKEY) { + debug("Received KEXGSS_HOSTKEY"); + if (serverhostkey) + fatal("Server host key received more than once"); + serverhostkey = + packet_get_string(&slen); + } + } while (type == SSH2_MSG_KEXGSS_HOSTKEY); + + switch (type) { + case SSH2_MSG_KEXGSS_CONTINUE: + debug("Received GSSAPI_CONTINUE"); + if (maj_status == GSS_S_COMPLETE) + fatal("GSSAPI Continue received from server when complete"); + recv_tok.value = packet_get_string(&strlen); + recv_tok.length = strlen; + break; + case SSH2_MSG_KEXGSS_COMPLETE: + debug("Received GSSAPI_COMPLETE"); + packet_get_bignum2(dh_server_pub); + msg_tok.value = packet_get_string(&strlen); + msg_tok.length = strlen; + + /* Is there a token included? */ + if (packet_get_char()) { + recv_tok.value= + packet_get_string(&strlen); + recv_tok.length = strlen; + /* If we're already complete - protocol error */ + if (maj_status == GSS_S_COMPLETE) + packet_disconnect("Protocol error: received token when complete"); + } else { + /* No token included */ + if (maj_status != GSS_S_COMPLETE) + packet_disconnect("Protocol error: did not receive final token"); + } + break; + case SSH2_MSG_KEXGSS_ERROR: + debug("Received Error"); + maj_status = packet_get_int(); + min_status = packet_get_int(); + msg = packet_get_string(NULL); + (void) packet_get_string_ptr(NULL); + fatal("GSSAPI Error: \n%.400s",msg); + default: + packet_disconnect("Protocol error: didn't expect packet type %d", + type); + } + token_ptr = &recv_tok; + } else { + /* No data, and not complete */ + if (maj_status != GSS_S_COMPLETE) + fatal("Not complete, and no token output"); + } + } while (maj_status & GSS_S_CONTINUE_NEEDED); + + /* + * We _must_ have received a COMPLETE message in reply from the + * server, which will have set dh_server_pub and msg_tok + */ + + if (type != SSH2_MSG_KEXGSS_COMPLETE) + fatal("Didn't receive a SSH2_MSG_KEXGSS_COMPLETE when I expected it"); + + /* Check f in range [1, p-1] */ + if (!dh_pub_is_valid(dh, dh_server_pub)) + packet_disconnect("bad server public DH value"); + + /* compute K=f^x mod p */ + klen = DH_size(dh); + kbuf = xmalloc(klen); + kout = DH_compute_key(kbuf, dh_server_pub, dh); + if (kout < 0) + fatal("DH_compute_key: failed"); + + shared_secret = BN_new(); + if (shared_secret == NULL) + fatal("kexgss_client: BN_new failed"); + + if (BN_bin2bn(kbuf, kout, shared_secret) == NULL) + fatal("kexdh_client: BN_bin2bn failed"); + + memset(kbuf, 0, klen); + free(kbuf); + + hashlen = sizeof(hash); + switch (ssh->kex->kex_type) { + case KEX_GSS_GRP1_SHA1: + case KEX_GSS_GRP14_SHA1: + kex_dh_hash( + ssh->kex->hash_alg, + ssh->kex->client_version_string, + ssh->kex->server_version_string, + buffer_ptr(ssh->kex->my), buffer_len(ssh->kex->my), + buffer_ptr(ssh->kex->peer), buffer_len(ssh->kex->peer), + (serverhostkey ? serverhostkey : empty), slen, + dh->pub_key, /* e */ + dh_server_pub, /* f */ + shared_secret, /* K */ + hash, &hashlen + ); + break; + case KEX_GSS_GEX_SHA1: + kexgex_hash( + ssh->kex->hash_alg, + ssh->kex->client_version_string, + ssh->kex->server_version_string, + buffer_ptr(ssh->kex->my), buffer_len(ssh->kex->my), + buffer_ptr(ssh->kex->peer), buffer_len(ssh->kex->peer), + (serverhostkey ? serverhostkey : empty), slen, + min, nbits, max, + dh->p, dh->g, + dh->pub_key, + dh_server_pub, + shared_secret, + hash, &hashlen + ); + break; + default: + fatal("%s: Unexpected KEX type %d", __func__, ssh->kex->kex_type); + } + + gssbuf.value = hash; + gssbuf.length = hashlen; + + /* Verify that the hash matches the MIC we just got. */ + if (GSS_ERROR(ssh_gssapi_checkmic(ctxt, &gssbuf, &msg_tok))) + packet_disconnect("Hash's MIC didn't verify"); + + free(msg_tok.value); + + DH_free(dh); + free(serverhostkey); + BN_clear_free(dh_server_pub); + + /* save session id */ + if (ssh->kex->session_id == NULL) { + ssh->kex->session_id_len = hashlen; + ssh->kex->session_id = xmalloc(ssh->kex->session_id_len); + memcpy(ssh->kex->session_id, hash, ssh->kex->session_id_len); + } + + if (ssh->kex->gss_deleg_creds) + ssh_gssapi_credentials_updated(ctxt); + + if (gss_kex_context == NULL) + gss_kex_context = ctxt; + else + ssh_gssapi_delete_ctx(&ctxt); + + kex_derive_keys_bn(ssh, hash, hashlen, shared_secret); + BN_clear_free(shared_secret); + return kex_send_newkeys(ssh); +} + +#endif /* GSSAPI */ diff --git a/kexgsss.c b/kexgsss.c new file mode 100644 index 000000000..38ca082ba --- /dev/null +++ b/kexgsss.c @@ -0,0 +1,295 @@ +/* + * Copyright (c) 2001-2009 Simon Wilkinson. 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. + * + * 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" + +#ifdef GSSAPI + +#include + +#include +#include + +#include "xmalloc.h" +#include "buffer.h" +#include "ssh2.h" +#include "key.h" +#include "cipher.h" +#include "kex.h" +#include "log.h" +#include "packet.h" +#include "dh.h" +#include "ssh-gss.h" +#include "monitor_wrap.h" +#include "misc.h" +#include "servconf.h" +#include "digest.h" + +extern ServerOptions options; + +int +kexgss_server(struct ssh *ssh) +{ + OM_uint32 maj_status, min_status; + + /* + * Some GSSAPI implementations use the input value of ret_flags (an + * output variable) as a means of triggering mechanism specific + * features. Initializing it to zero avoids inadvertently + * activating this non-standard behaviour. + */ + + OM_uint32 ret_flags = 0; + gss_buffer_desc gssbuf, recv_tok, msg_tok; + gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; + Gssctxt *ctxt = NULL; + u_int slen, klen, kout; + u_char *kbuf; + DH *dh; + int min = -1, max = -1, nbits = -1; + BIGNUM *shared_secret = NULL; + BIGNUM *dh_client_pub = NULL; + int type = 0; + gss_OID oid; + char *mechs; + u_char hash[SSH_DIGEST_MAX_LENGTH]; + size_t hashlen; + + /* Initialise GSSAPI */ + + /* If we're rekeying, privsep means that some of the private structures + * in the GSSAPI code are no longer available. This kludges them back + * into life + */ + if (!ssh_gssapi_oid_table_ok()) { + mechs = ssh_gssapi_server_mechanisms(); + free(mechs); + } + + debug2("%s: Identifying %s", __func__, ssh->kex->name); + oid = ssh_gssapi_id_kex(NULL, ssh->kex->name, ssh->kex->kex_type); + if (oid == GSS_C_NO_OID) + fatal("Unknown gssapi mechanism"); + + debug2("%s: Acquiring credentials", __func__); + + if (GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctxt, oid)))) + fatal("Unable to acquire credentials for the server"); + + switch (ssh->kex->kex_type) { + case KEX_GSS_GRP1_SHA1: + dh = dh_new_group1(); + break; + case KEX_GSS_GRP14_SHA1: + dh = dh_new_group14(); + break; + case KEX_GSS_GEX_SHA1: + debug("Doing group exchange"); + packet_read_expect(SSH2_MSG_KEXGSS_GROUPREQ); + min = packet_get_int(); + nbits = packet_get_int(); + max = packet_get_int(); + packet_check_eom(); + if (max < min || nbits < min || max < nbits) + fatal("GSS_GEX, bad parameters: %d !< %d !< %d", + min, nbits, max); + dh = PRIVSEP(choose_dh(MAX(DH_GRP_MIN, min), + nbits, MIN(DH_GRP_MAX, max))); + if (dh == NULL) + packet_disconnect("Protocol error: no matching group found"); + + packet_start(SSH2_MSG_KEXGSS_GROUP); + packet_put_bignum2(dh->p); + packet_put_bignum2(dh->g); + packet_send(); + + packet_write_wait(); + break; + default: + fatal("%s: Unexpected KEX type %d", __func__, ssh->kex->kex_type); + } + + dh_gen_key(dh, ssh->kex->we_need * 8); + + do { + debug("Wait SSH2_MSG_GSSAPI_INIT"); + type = packet_read(); + switch(type) { + case SSH2_MSG_KEXGSS_INIT: + if (dh_client_pub != NULL) + fatal("Received KEXGSS_INIT after initialising"); + recv_tok.value = packet_get_string(&slen); + recv_tok.length = slen; + + if ((dh_client_pub = BN_new()) == NULL) + fatal("dh_client_pub == NULL"); + + packet_get_bignum2(dh_client_pub); + + /* Send SSH_MSG_KEXGSS_HOSTKEY here, if we want */ + break; + case SSH2_MSG_KEXGSS_CONTINUE: + recv_tok.value = packet_get_string(&slen); + recv_tok.length = slen; + break; + default: + packet_disconnect( + "Protocol error: didn't expect packet type %d", + type); + } + + maj_status = PRIVSEP(ssh_gssapi_accept_ctx(ctxt, &recv_tok, + &send_tok, &ret_flags)); + + free(recv_tok.value); + + if (maj_status != GSS_S_COMPLETE && send_tok.length == 0) + fatal("Zero length token output when incomplete"); + + if (dh_client_pub == NULL) + fatal("No client public key"); + + if (maj_status & GSS_S_CONTINUE_NEEDED) { + debug("Sending GSSAPI_CONTINUE"); + packet_start(SSH2_MSG_KEXGSS_CONTINUE); + packet_put_string(send_tok.value, send_tok.length); + packet_send(); + gss_release_buffer(&min_status, &send_tok); + } + } while (maj_status & GSS_S_CONTINUE_NEEDED); + + if (GSS_ERROR(maj_status)) { + if (send_tok.length > 0) { + packet_start(SSH2_MSG_KEXGSS_CONTINUE); + packet_put_string(send_tok.value, send_tok.length); + packet_send(); + } + fatal("accept_ctx died"); + } + + if (!(ret_flags & GSS_C_MUTUAL_FLAG)) + fatal("Mutual Authentication flag wasn't set"); + + if (!(ret_flags & GSS_C_INTEG_FLAG)) + fatal("Integrity flag wasn't set"); + + if (!dh_pub_is_valid(dh, dh_client_pub)) + packet_disconnect("bad client public DH value"); + + klen = DH_size(dh); + kbuf = xmalloc(klen); + kout = DH_compute_key(kbuf, dh_client_pub, dh); + if (kout < 0) + fatal("DH_compute_key: failed"); + + shared_secret = BN_new(); + if (shared_secret == NULL) + fatal("kexgss_server: BN_new failed"); + + if (BN_bin2bn(kbuf, kout, shared_secret) == NULL) + fatal("kexgss_server: BN_bin2bn failed"); + + memset(kbuf, 0, klen); + free(kbuf); + + hashlen = sizeof(hash); + switch (ssh->kex->kex_type) { + case KEX_GSS_GRP1_SHA1: + case KEX_GSS_GRP14_SHA1: + kex_dh_hash( + ssh->kex->hash_alg, + ssh->kex->client_version_string, ssh->kex->server_version_string, + buffer_ptr(ssh->kex->peer), buffer_len(ssh->kex->peer), + buffer_ptr(ssh->kex->my), buffer_len(ssh->kex->my), + NULL, 0, /* Change this if we start sending host keys */ + dh_client_pub, dh->pub_key, shared_secret, + hash, &hashlen + ); + break; + case KEX_GSS_GEX_SHA1: + kexgex_hash( + ssh->kex->hash_alg, + ssh->kex->client_version_string, ssh->kex->server_version_string, + buffer_ptr(ssh->kex->peer), buffer_len(ssh->kex->peer), + buffer_ptr(ssh->kex->my), buffer_len(ssh->kex->my), + NULL, 0, + min, nbits, max, + dh->p, dh->g, + dh_client_pub, + dh->pub_key, + shared_secret, + hash, &hashlen + ); + break; + default: + fatal("%s: Unexpected KEX type %d", __func__, ssh->kex->kex_type); + } + + BN_clear_free(dh_client_pub); + + if (ssh->kex->session_id == NULL) { + ssh->kex->session_id_len = hashlen; + ssh->kex->session_id = xmalloc(ssh->kex->session_id_len); + memcpy(ssh->kex->session_id, hash, ssh->kex->session_id_len); + } + + gssbuf.value = hash; + gssbuf.length = hashlen; + + if (GSS_ERROR(PRIVSEP(ssh_gssapi_sign(ctxt,&gssbuf,&msg_tok)))) + fatal("Couldn't get MIC"); + + packet_start(SSH2_MSG_KEXGSS_COMPLETE); + packet_put_bignum2(dh->pub_key); + packet_put_string(msg_tok.value,msg_tok.length); + + if (send_tok.length != 0) { + packet_put_char(1); /* true */ + packet_put_string(send_tok.value, send_tok.length); + } else { + packet_put_char(0); /* false */ + } + packet_send(); + + gss_release_buffer(&min_status, &send_tok); + gss_release_buffer(&min_status, &msg_tok); + + if (gss_kex_context == NULL) + gss_kex_context = ctxt; + else + ssh_gssapi_delete_ctx(&ctxt); + + DH_free(dh); + + kex_derive_keys_bn(ssh, hash, hashlen, shared_secret); + BN_clear_free(shared_secret); + kex_send_newkeys(ssh); + + /* If this was a rekey, then save out any delegated credentials we + * just exchanged. */ + if (options.gss_store_rekey) + ssh_gssapi_rekey_creds(); + return 0; +} +#endif /* GSSAPI */ diff --git a/monitor.c b/monitor.c index 96d22b7e4..506645c7c 100644 --- a/monitor.c +++ b/monitor.c @@ -157,6 +157,8 @@ int mm_answer_gss_setup_ctx(int, Buffer *); int mm_answer_gss_accept_ctx(int, Buffer *); int mm_answer_gss_userok(int, Buffer *); int mm_answer_gss_checkmic(int, Buffer *); +int mm_answer_gss_sign(int, Buffer *); +int mm_answer_gss_updatecreds(int, Buffer *); #endif #ifdef SSH_AUDIT_EVENTS @@ -230,11 +232,18 @@ struct mon_table mon_dispatch_proto20[] = { {MONITOR_REQ_GSSSTEP, 0, mm_answer_gss_accept_ctx}, {MONITOR_REQ_GSSUSEROK, MON_ONCE|MON_AUTHDECIDE, mm_answer_gss_userok}, {MONITOR_REQ_GSSCHECKMIC, MON_ONCE, mm_answer_gss_checkmic}, + {MONITOR_REQ_GSSSIGN, MON_ONCE, mm_answer_gss_sign}, #endif {0, 0, NULL} }; struct mon_table mon_dispatch_postauth20[] = { +#ifdef GSSAPI + {MONITOR_REQ_GSSSETUP, 0, mm_answer_gss_setup_ctx}, + {MONITOR_REQ_GSSSTEP, 0, mm_answer_gss_accept_ctx}, + {MONITOR_REQ_GSSSIGN, 0, mm_answer_gss_sign}, + {MONITOR_REQ_GSSUPCREDS, 0, mm_answer_gss_updatecreds}, +#endif #ifdef WITH_OPENSSL {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, #endif @@ -302,6 +311,10 @@ monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor) /* Permit requests for moduli and signatures */ monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); +#ifdef GSSAPI + /* and for the GSSAPI key exchange */ + monitor_permit(mon_dispatch, MONITOR_REQ_GSSSETUP, 1); +#endif /* The first few requests do not require asynchronous access */ while (!authenticated) { @@ -402,6 +415,10 @@ monitor_child_postauth(struct monitor *pmonitor) monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); +#ifdef GSSAPI + /* and for the GSSAPI key exchange */ + monitor_permit(mon_dispatch, MONITOR_REQ_GSSSETUP, 1); +#endif if (!no_pty_flag) { monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); @@ -1606,6 +1623,13 @@ monitor_apply_keystate(struct monitor *pmonitor) # endif #endif /* WITH_OPENSSL */ kex->kex[KEX_C25519_SHA256] = kexc25519_server; +#ifdef GSSAPI + if (options.gss_keyex) { + kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_server; + kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_server; + kex->kex[KEX_GSS_GEX_SHA1] = kexgss_server; + } +#endif kex->load_host_public_key=&get_hostkey_public_by_type; kex->load_host_private_key=&get_hostkey_private_by_type; kex->host_key_index=&get_hostkey_index; @@ -1685,8 +1709,8 @@ mm_answer_gss_setup_ctx(int sock, Buffer *m) OM_uint32 major; u_int len; - if (!options.gss_authentication) - fatal("%s: GSSAPI authentication not enabled", __func__); + if (!options.gss_authentication && !options.gss_keyex) + fatal("%s: GSSAPI not enabled", __func__); goid.elements = buffer_get_string(m, &len); goid.length = len; @@ -1715,8 +1739,8 @@ mm_answer_gss_accept_ctx(int sock, Buffer *m) OM_uint32 flags = 0; /* GSI needs this */ u_int len; - if (!options.gss_authentication) - fatal("%s: GSSAPI authentication not enabled", __func__); + if (!options.gss_authentication && !options.gss_keyex) + fatal("%s: GSSAPI not enabled", __func__); in.value = buffer_get_string(m, &len); in.length = len; @@ -1735,6 +1759,7 @@ mm_answer_gss_accept_ctx(int sock, Buffer *m) monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); + monitor_permit(mon_dispatch, MONITOR_REQ_GSSSIGN, 1); } return (0); } @@ -1746,8 +1771,8 @@ mm_answer_gss_checkmic(int sock, Buffer *m) OM_uint32 ret; u_int len; - if (!options.gss_authentication) - fatal("%s: GSSAPI authentication not enabled", __func__); + if (!options.gss_authentication && !options.gss_keyex) + fatal("%s: GSSAPI not enabled", __func__); gssbuf.value = buffer_get_string(m, &len); gssbuf.length = len; @@ -1775,10 +1800,11 @@ mm_answer_gss_userok(int sock, Buffer *m) { int authenticated; - if (!options.gss_authentication) - fatal("%s: GSSAPI authentication not enabled", __func__); + if (!options.gss_authentication && !options.gss_keyex) + fatal("%s: GSSAPI not enabled", __func__); - authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); + authenticated = authctxt->valid && + ssh_gssapi_userok(authctxt->user, authctxt->pw); buffer_clear(m); buffer_put_int(m, authenticated); @@ -1791,5 +1817,76 @@ mm_answer_gss_userok(int sock, Buffer *m) /* Monitor loop will terminate if authenticated */ return (authenticated); } + +int +mm_answer_gss_sign(int socket, Buffer *m) +{ + gss_buffer_desc data; + gss_buffer_desc hash = GSS_C_EMPTY_BUFFER; + OM_uint32 major, minor; + u_int len; + + if (!options.gss_authentication && !options.gss_keyex) + fatal("%s: GSSAPI not enabled", __func__); + + data.value = buffer_get_string(m, &len); + data.length = len; + if (data.length != 20) + fatal("%s: data length incorrect: %d", __func__, + (int) data.length); + + /* Save the session ID on the first time around */ + if (session_id2_len == 0) { + session_id2_len = data.length; + session_id2 = xmalloc(session_id2_len); + memcpy(session_id2, data.value, session_id2_len); + } + major = ssh_gssapi_sign(gsscontext, &data, &hash); + + free(data.value); + + buffer_clear(m); + buffer_put_int(m, major); + buffer_put_string(m, hash.value, hash.length); + + mm_request_send(socket, MONITOR_ANS_GSSSIGN, m); + + gss_release_buffer(&minor, &hash); + + /* Turn on getpwnam permissions */ + monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); + + /* And credential updating, for when rekeying */ + monitor_permit(mon_dispatch, MONITOR_REQ_GSSUPCREDS, 1); + + return (0); +} + +int +mm_answer_gss_updatecreds(int socket, Buffer *m) { + ssh_gssapi_ccache store; + int ok; + + if (!options.gss_authentication && !options.gss_keyex) + fatal("%s: GSSAPI not enabled", __func__); + + store.filename = buffer_get_string(m, NULL); + store.envvar = buffer_get_string(m, NULL); + store.envval = buffer_get_string(m, NULL); + + ok = ssh_gssapi_update_creds(&store); + + free(store.filename); + free(store.envvar); + free(store.envval); + + buffer_clear(m); + buffer_put_int(m, ok); + + mm_request_send(socket, MONITOR_ANS_GSSUPCREDS, m); + + return(0); +} + #endif /* GSSAPI */ diff --git a/monitor.h b/monitor.h index d68f67458..ec41404c7 100644 --- a/monitor.h +++ b/monitor.h @@ -65,6 +65,9 @@ enum monitor_reqtype { MONITOR_REQ_PAM_FREE_CTX = 110, MONITOR_ANS_PAM_FREE_CTX = 111, MONITOR_REQ_AUDIT_EVENT = 112, MONITOR_REQ_AUDIT_COMMAND = 113, + MONITOR_REQ_GSSSIGN = 150, MONITOR_ANS_GSSSIGN = 151, + MONITOR_REQ_GSSUPCREDS = 152, MONITOR_ANS_GSSUPCREDS = 153, + }; struct monitor { diff --git a/monitor_wrap.c b/monitor_wrap.c index 64ff92885..d5cb640af 100644 --- a/monitor_wrap.c +++ b/monitor_wrap.c @@ -924,7 +924,7 @@ mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic) } int -mm_ssh_gssapi_userok(char *user) +mm_ssh_gssapi_userok(char *user, struct passwd *pw) { Buffer m; int authenticated = 0; @@ -941,5 +941,50 @@ mm_ssh_gssapi_userok(char *user) debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not "); return (authenticated); } + +OM_uint32 +mm_ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_desc *data, gss_buffer_desc *hash) +{ + Buffer m; + OM_uint32 major; + u_int len; + + buffer_init(&m); + buffer_put_string(&m, data->value, data->length); + + mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSIGN, &m); + mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSIGN, &m); + + major = buffer_get_int(&m); + hash->value = buffer_get_string(&m, &len); + hash->length = len; + + buffer_free(&m); + + return(major); +} + +int +mm_ssh_gssapi_update_creds(ssh_gssapi_ccache *store) +{ + Buffer m; + int ok; + + buffer_init(&m); + + buffer_put_cstring(&m, store->filename ? store->filename : ""); + buffer_put_cstring(&m, store->envvar ? store->envvar : ""); + buffer_put_cstring(&m, store->envval ? store->envval : ""); + + mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUPCREDS, &m); + mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSUPCREDS, &m); + + ok = buffer_get_int(&m); + + buffer_free(&m); + + return (ok); +} + #endif /* GSSAPI */ diff --git a/monitor_wrap.h b/monitor_wrap.h index db5902f55..8f9dd8961 100644 --- a/monitor_wrap.h +++ b/monitor_wrap.h @@ -55,8 +55,10 @@ int mm_key_verify(Key *, u_char *, u_int, u_char *, u_int); OM_uint32 mm_ssh_gssapi_server_ctx(Gssctxt **, gss_OID); OM_uint32 mm_ssh_gssapi_accept_ctx(Gssctxt *, gss_buffer_desc *, gss_buffer_desc *, OM_uint32 *); -int mm_ssh_gssapi_userok(char *user); +int mm_ssh_gssapi_userok(char *user, struct passwd *); OM_uint32 mm_ssh_gssapi_checkmic(Gssctxt *, gss_buffer_t, gss_buffer_t); +OM_uint32 mm_ssh_gssapi_sign(Gssctxt *, gss_buffer_t, gss_buffer_t); +int mm_ssh_gssapi_update_creds(ssh_gssapi_ccache *); #endif #ifdef USE_PAM diff --git a/readconf.c b/readconf.c index 9d59493f0..00d9cc302 100644 --- a/readconf.c +++ b/readconf.c @@ -160,6 +160,8 @@ typedef enum { oClearAllForwardings, oNoHostAuthenticationForLocalhost, oEnableSSHKeysign, oRekeyLimit, oVerifyHostKeyDNS, oConnectTimeout, oAddressFamily, oGssAuthentication, oGssDelegateCreds, + oGssTrustDns, oGssKeyEx, oGssClientIdentity, oGssRenewalRekey, + oGssServerIdentity, oServerAliveInterval, oServerAliveCountMax, oIdentitiesOnly, oSendEnv, oControlPath, oControlMaster, oControlPersist, oHashKnownHosts, @@ -196,10 +198,20 @@ static struct { /* Sometimes-unsupported options */ #if defined(GSSAPI) { "gssapiauthentication", oGssAuthentication }, + { "gssapikeyexchange", oGssKeyEx }, { "gssapidelegatecredentials", oGssDelegateCreds }, + { "gssapitrustdns", oGssTrustDns }, + { "gssapiclientidentity", oGssClientIdentity }, + { "gssapiserveridentity", oGssServerIdentity }, + { "gssapirenewalforcesrekey", oGssRenewalRekey }, # else { "gssapiauthentication", oUnsupported }, + { "gssapikeyexchange", oUnsupported }, { "gssapidelegatecredentials", oUnsupported }, + { "gssapitrustdns", oUnsupported }, + { "gssapiclientidentity", oUnsupported }, + { "gssapiserveridentity", oUnsupported }, + { "gssapirenewalforcesrekey", oUnsupported }, #endif #ifdef ENABLE_PKCS11 { "smartcarddevice", oPKCS11Provider }, @@ -973,10 +985,30 @@ parse_time: intptr = &options->gss_authentication; goto parse_flag; + case oGssKeyEx: + intptr = &options->gss_keyex; + goto parse_flag; + case oGssDelegateCreds: intptr = &options->gss_deleg_creds; goto parse_flag; + case oGssTrustDns: + intptr = &options->gss_trust_dns; + goto parse_flag; + + case oGssClientIdentity: + charptr = &options->gss_client_identity; + goto parse_string; + + case oGssServerIdentity: + charptr = &options->gss_server_identity; + goto parse_string; + + case oGssRenewalRekey: + intptr = &options->gss_renewal_rekey; + goto parse_flag; + case oBatchMode: intptr = &options->batch_mode; goto parse_flag; @@ -1798,7 +1830,12 @@ initialize_options(Options * options) options->pubkey_authentication = -1; options->challenge_response_authentication = -1; options->gss_authentication = -1; + options->gss_keyex = -1; options->gss_deleg_creds = -1; + options->gss_trust_dns = -1; + options->gss_renewal_rekey = -1; + options->gss_client_identity = NULL; + options->gss_server_identity = NULL; options->password_authentication = -1; options->kbd_interactive_authentication = -1; options->kbd_interactive_devices = NULL; @@ -1942,8 +1979,14 @@ fill_default_options(Options * options) options->challenge_response_authentication = 1; if (options->gss_authentication == -1) options->gss_authentication = 0; + if (options->gss_keyex == -1) + options->gss_keyex = 0; if (options->gss_deleg_creds == -1) options->gss_deleg_creds = 0; + if (options->gss_trust_dns == -1) + options->gss_trust_dns = 0; + if (options->gss_renewal_rekey == -1) + options->gss_renewal_rekey = 0; if (options->password_authentication == -1) options->password_authentication = 1; if (options->kbd_interactive_authentication == -1) diff --git a/readconf.h b/readconf.h index cef55f71c..fd3d7c75d 100644 --- a/readconf.h +++ b/readconf.h @@ -45,7 +45,12 @@ typedef struct { int challenge_response_authentication; /* Try S/Key or TIS, authentication. */ int gss_authentication; /* Try GSS authentication */ + int gss_keyex; /* Try GSS key exchange */ int gss_deleg_creds; /* Delegate GSS credentials */ + int gss_trust_dns; /* Trust DNS for GSS canonicalization */ + int gss_renewal_rekey; /* Credential renewal forces rekey */ + char *gss_client_identity; /* Principal to initiate GSSAPI with */ + char *gss_server_identity; /* GSSAPI target principal */ int password_authentication; /* Try password * authentication. */ int kbd_interactive_authentication; /* Try keyboard-interactive auth. */ diff --git a/servconf.c b/servconf.c index 56b831652..d796b7c8a 100644 --- a/servconf.c +++ b/servconf.c @@ -113,8 +113,10 @@ initialize_server_options(ServerOptions *options) options->kerberos_ticket_cleanup = -1; options->kerberos_get_afs_token = -1; options->gss_authentication=-1; + options->gss_keyex = -1; options->gss_cleanup_creds = -1; options->gss_strict_acceptor = -1; + options->gss_store_rekey = -1; options->password_authentication = -1; options->kbd_interactive_authentication = -1; options->challenge_response_authentication = -1; @@ -267,10 +269,14 @@ fill_default_server_options(ServerOptions *options) options->kerberos_get_afs_token = 0; if (options->gss_authentication == -1) options->gss_authentication = 0; + if (options->gss_keyex == -1) + options->gss_keyex = 0; if (options->gss_cleanup_creds == -1) options->gss_cleanup_creds = 1; if (options->gss_strict_acceptor == -1) options->gss_strict_acceptor = 1; + if (options->gss_store_rekey == -1) + options->gss_store_rekey = 0; if (options->password_authentication == -1) options->password_authentication = 1; if (options->kbd_interactive_authentication == -1) @@ -407,6 +413,7 @@ typedef enum { sHostKeyAlgorithms, sClientAliveInterval, sClientAliveCountMax, sAuthorizedKeysFile, sGssAuthentication, sGssCleanupCreds, sGssStrictAcceptor, + sGssKeyEx, sGssStoreRekey, sAcceptEnv, sPermitTunnel, sMatch, sPermitOpen, sForceCommand, sChrootDirectory, sUsePrivilegeSeparation, sAllowAgentForwarding, @@ -480,12 +487,20 @@ static struct { #ifdef GSSAPI { "gssapiauthentication", sGssAuthentication, SSHCFG_ALL }, { "gssapicleanupcredentials", sGssCleanupCreds, SSHCFG_GLOBAL }, + { "gssapicleanupcreds", sGssCleanupCreds, SSHCFG_GLOBAL }, { "gssapistrictacceptorcheck", sGssStrictAcceptor, SSHCFG_GLOBAL }, + { "gssapikeyexchange", sGssKeyEx, SSHCFG_GLOBAL }, + { "gssapistorecredentialsonrekey", sGssStoreRekey, SSHCFG_GLOBAL }, #else { "gssapiauthentication", sUnsupported, SSHCFG_ALL }, { "gssapicleanupcredentials", sUnsupported, SSHCFG_GLOBAL }, + { "gssapicleanupcreds", sUnsupported, SSHCFG_GLOBAL }, { "gssapistrictacceptorcheck", sUnsupported, SSHCFG_GLOBAL }, + { "gssapikeyexchange", sUnsupported, SSHCFG_GLOBAL }, + { "gssapistorecredentialsonrekey", sUnsupported, SSHCFG_GLOBAL }, #endif + { "gssusesessionccache", sUnsupported, SSHCFG_GLOBAL }, + { "gssapiusesessioncredcache", sUnsupported, SSHCFG_GLOBAL }, { "passwordauthentication", sPasswordAuthentication, SSHCFG_ALL }, { "kbdinteractiveauthentication", sKbdInteractiveAuthentication, SSHCFG_ALL }, { "challengeresponseauthentication", sChallengeResponseAuthentication, SSHCFG_GLOBAL }, @@ -1217,6 +1232,10 @@ process_server_config_line(ServerOptions *options, char *line, intptr = &options->gss_authentication; goto parse_flag; + case sGssKeyEx: + intptr = &options->gss_keyex; + goto parse_flag; + case sGssCleanupCreds: intptr = &options->gss_cleanup_creds; goto parse_flag; @@ -1225,6 +1244,10 @@ process_server_config_line(ServerOptions *options, char *line, intptr = &options->gss_strict_acceptor; goto parse_flag; + case sGssStoreRekey: + intptr = &options->gss_store_rekey; + goto parse_flag; + case sPasswordAuthentication: intptr = &options->password_authentication; goto parse_flag; @@ -2250,7 +2273,10 @@ dump_config(ServerOptions *o) #endif #ifdef GSSAPI dump_cfg_fmtint(sGssAuthentication, o->gss_authentication); + dump_cfg_fmtint(sGssKeyEx, o->gss_keyex); dump_cfg_fmtint(sGssCleanupCreds, o->gss_cleanup_creds); + dump_cfg_fmtint(sGssStrictAcceptor, o->gss_strict_acceptor); + dump_cfg_fmtint(sGssStoreRekey, o->gss_store_rekey); #endif dump_cfg_fmtint(sPasswordAuthentication, o->password_authentication); dump_cfg_fmtint(sKbdInteractiveAuthentication, diff --git a/servconf.h b/servconf.h index 5853a9747..90dfa4c24 100644 --- a/servconf.h +++ b/servconf.h @@ -112,8 +112,10 @@ typedef struct { int kerberos_get_afs_token; /* If true, try to get AFS token if * authenticated with Kerberos. */ int gss_authentication; /* If true, permit GSSAPI authentication */ + int gss_keyex; /* If true, permit GSSAPI key exchange */ int gss_cleanup_creds; /* If true, destroy cred cache on logout */ int gss_strict_acceptor; /* If true, restrict the GSSAPI acceptor name */ + int gss_store_rekey; int password_authentication; /* If true, permit password * authentication. */ int kbd_interactive_authentication; /* If true, permit */ diff --git a/ssh-gss.h b/ssh-gss.h index a99d7f08b..914701bcf 100644 --- a/ssh-gss.h +++ b/ssh-gss.h @@ -1,6 +1,6 @@ /* $OpenBSD: ssh-gss.h,v 1.11 2014/02/26 20:28:44 djm Exp $ */ /* - * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved. + * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -61,10 +61,22 @@ #define SSH_GSS_OIDTYPE 0x06 +#define SSH2_MSG_KEXGSS_INIT 30 +#define SSH2_MSG_KEXGSS_CONTINUE 31 +#define SSH2_MSG_KEXGSS_COMPLETE 32 +#define SSH2_MSG_KEXGSS_HOSTKEY 33 +#define SSH2_MSG_KEXGSS_ERROR 34 +#define SSH2_MSG_KEXGSS_GROUPREQ 40 +#define SSH2_MSG_KEXGSS_GROUP 41 +#define KEX_GSS_GRP1_SHA1_ID "gss-group1-sha1-" +#define KEX_GSS_GRP14_SHA1_ID "gss-group14-sha1-" +#define KEX_GSS_GEX_SHA1_ID "gss-gex-sha1-" + typedef struct { char *filename; char *envvar; char *envval; + struct passwd *owner; void *data; } ssh_gssapi_ccache; @@ -72,8 +84,11 @@ typedef struct { gss_buffer_desc displayname; gss_buffer_desc exportedname; gss_cred_id_t creds; + gss_name_t name; struct ssh_gssapi_mech_struct *mech; ssh_gssapi_ccache store; + int used; + int updated; } ssh_gssapi_client; typedef struct ssh_gssapi_mech_struct { @@ -84,6 +99,7 @@ typedef struct ssh_gssapi_mech_struct { int (*userok) (ssh_gssapi_client *, char *); int (*localname) (ssh_gssapi_client *, char **); void (*storecreds) (ssh_gssapi_client *); + int (*updatecreds) (ssh_gssapi_ccache *, ssh_gssapi_client *); } ssh_gssapi_mech; typedef struct { @@ -94,10 +110,11 @@ typedef struct { gss_OID oid; /* client */ gss_cred_id_t creds; /* server */ gss_name_t client; /* server */ - gss_cred_id_t client_creds; /* server */ + gss_cred_id_t client_creds; /* both */ } Gssctxt; extern ssh_gssapi_mech *supported_mechs[]; +extern Gssctxt *gss_kex_context; int ssh_gssapi_check_oid(Gssctxt *, void *, size_t); void ssh_gssapi_set_oid_data(Gssctxt *, void *, size_t); @@ -119,16 +136,32 @@ void ssh_gssapi_build_ctx(Gssctxt **); void ssh_gssapi_delete_ctx(Gssctxt **); OM_uint32 ssh_gssapi_sign(Gssctxt *, gss_buffer_t, gss_buffer_t); void ssh_gssapi_buildmic(Buffer *, const char *, const char *, const char *); -int ssh_gssapi_check_mechanism(Gssctxt **, gss_OID, const char *); +int ssh_gssapi_check_mechanism(Gssctxt **, gss_OID, const char *, const char *); +OM_uint32 ssh_gssapi_client_identity(Gssctxt *, const char *); +int ssh_gssapi_credentials_updated(Gssctxt *); /* In the server */ +typedef int ssh_gssapi_check_fn(Gssctxt **, gss_OID, const char *, + const char *); +char *ssh_gssapi_client_mechanisms(const char *, const char *); +char *ssh_gssapi_kex_mechs(gss_OID_set, ssh_gssapi_check_fn *, const char *, + const char *); +gss_OID ssh_gssapi_id_kex(Gssctxt *, char *, int); +int ssh_gssapi_server_check_mech(Gssctxt **,gss_OID, const char *, + const char *); OM_uint32 ssh_gssapi_server_ctx(Gssctxt **, gss_OID); -int ssh_gssapi_userok(char *name); +int ssh_gssapi_userok(char *name, struct passwd *); OM_uint32 ssh_gssapi_checkmic(Gssctxt *, gss_buffer_t, gss_buffer_t); void ssh_gssapi_do_child(char ***, u_int *); void ssh_gssapi_cleanup_creds(void); void ssh_gssapi_storecreds(void); +char *ssh_gssapi_server_mechanisms(void); +int ssh_gssapi_oid_table_ok(void); + +int ssh_gssapi_update_creds(ssh_gssapi_ccache *store); +void ssh_gssapi_rekey_creds(void); + #endif /* GSSAPI */ #endif /* _SSH_GSS_H */ diff --git a/ssh_config b/ssh_config index 90fb63f0b..4e879cd20 100644 --- a/ssh_config +++ b/ssh_config @@ -26,6 +26,8 @@ # HostbasedAuthentication no # GSSAPIAuthentication no # GSSAPIDelegateCredentials no +# GSSAPIKeyExchange no +# GSSAPITrustDNS no # BatchMode no # CheckHostIP yes # AddressFamily any diff --git a/ssh_config.5 b/ssh_config.5 index 532745b2f..ec60273ea 100644 --- a/ssh_config.5 +++ b/ssh_config.5 @@ -752,10 +752,42 @@ The default is Specifies whether user authentication based on GSSAPI is allowed. The default is .Cm no . +.It Cm GSSAPIKeyExchange +Specifies whether key exchange based on GSSAPI may be used. When using +GSSAPI key exchange the server need not have a host key. +The default is +.Cm no . +.It Cm GSSAPIClientIdentity +If set, specifies the GSSAPI client identity that ssh should use when +connecting to the server. The default is unset, which means that the default +identity will be used. +.It Cm GSSAPIServerIdentity +If set, specifies the GSSAPI server identity that ssh should expect when +connecting to the server. The default is unset, which means that the +expected GSSAPI server identity will be determined from the target +hostname. .It Cm GSSAPIDelegateCredentials Forward (delegate) credentials to the server. The default is .Cm no . +.It Cm GSSAPIRenewalForcesRekey +If set to +.Cm yes +then renewal of the client's GSSAPI credentials will force the rekeying of the +ssh connection. With a compatible server, this can delegate the renewed +credentials to a session on the server. +The default is +.Cm no . +.It Cm GSSAPITrustDns +Set to +.Cm yes +to indicate that the DNS is trusted to securely canonicalize +the name of the host being connected to. If +.Cm no , +the hostname entered on the +command line will be passed untouched to the GSSAPI library. +The default is +.Cm no . .It Cm HashKnownHosts Indicates that .Xr ssh 1 diff --git a/sshconnect2.c b/sshconnect2.c index f8a54beea..5743c2c41 100644 --- a/sshconnect2.c +++ b/sshconnect2.c @@ -162,6 +162,11 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port) struct kex *kex; int r; +#ifdef GSSAPI + char *orig = NULL, *gss = NULL; + char *gss_host = NULL; +#endif + xxx_host = host; xxx_hostaddr = hostaddr; @@ -192,6 +197,35 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port) order_hostkeyalgs(host, hostaddr, port)); } +#ifdef GSSAPI + if (options.gss_keyex) { + /* Add the GSSAPI mechanisms currently supported on this + * client to the key exchange algorithm proposal */ + orig = myproposal[PROPOSAL_KEX_ALGS]; + + if (options.gss_server_identity) + gss_host = xstrdup(options.gss_server_identity); + else if (options.gss_trust_dns) + gss_host = remote_hostname(active_state); + else + gss_host = xstrdup(host); + + gss = ssh_gssapi_client_mechanisms(gss_host, + options.gss_client_identity); + if (gss) { + debug("Offering GSSAPI proposal: %s", gss); + xasprintf(&myproposal[PROPOSAL_KEX_ALGS], + "%s,%s", gss, orig); + + /* If we've got GSSAPI algorithms, then we also + * support the 'null' hostkey, as a last resort */ + orig = myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]; + xasprintf(&myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS], + "%s,null", orig); + } + } +#endif + if (options.rekey_limit || options.rekey_interval) packet_set_rekey_limits(options.rekey_limit, options.rekey_interval); @@ -213,15 +247,41 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port) # endif #endif kex->kex[KEX_C25519_SHA256] = kexc25519_client; +#ifdef GSSAPI + if (options.gss_keyex) { + kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_client; + kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_client; + kex->kex[KEX_GSS_GEX_SHA1] = kexgss_client; + } +#endif kex->client_version_string=client_version_string; kex->server_version_string=server_version_string; kex->verify_host_key=&verify_host_key_callback; +#ifdef GSSAPI + if (options.gss_keyex) { + kex->gss_deleg_creds = options.gss_deleg_creds; + kex->gss_trust_dns = options.gss_trust_dns; + kex->gss_client = options.gss_client_identity; + kex->gss_host = gss_host; + } +#endif + dispatch_run(DISPATCH_BLOCK, &kex->done, active_state); /* remove ext-info from the KEX proposals for rekeying */ myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(options.kex_algorithms); +#ifdef GSSAPI + /* repair myproposal after it was crumpled by the */ + /* ext-info removal above */ + if (gss) { + orig = myproposal[PROPOSAL_KEX_ALGS]; + xasprintf(&myproposal[PROPOSAL_KEX_ALGS], + "%s,%s", gss, orig); + free(gss); + } +#endif if ((r = kex_prop2buf(kex->my, myproposal)) != 0) fatal("kex_prop2buf: %s", ssh_err(r)); @@ -311,6 +371,7 @@ int input_gssapi_token(int type, u_int32_t, void *); int input_gssapi_hash(int type, u_int32_t, void *); int input_gssapi_error(int, u_int32_t, void *); int input_gssapi_errtok(int, u_int32_t, void *); +int userauth_gsskeyex(Authctxt *authctxt); #endif void userauth(Authctxt *, char *); @@ -327,6 +388,11 @@ static char *authmethods_get(void); Authmethod authmethods[] = { #ifdef GSSAPI + {"gssapi-keyex", + userauth_gsskeyex, + NULL, + &options.gss_authentication, + NULL}, {"gssapi-with-mic", userauth_gssapi, NULL, @@ -652,25 +718,40 @@ userauth_gssapi(Authctxt *authctxt) static u_int mech = 0; OM_uint32 min; int ok = 0; + char *gss_host; + + if (options.gss_server_identity) + gss_host = xstrdup(options.gss_server_identity); + else if (options.gss_trust_dns) + gss_host = remote_hostname(active_state); + else + gss_host = xstrdup(authctxt->host); /* Try one GSSAPI method at a time, rather than sending them all at * once. */ if (gss_supported == NULL) - gss_indicate_mechs(&min, &gss_supported); + if (GSS_ERROR(gss_indicate_mechs(&min, &gss_supported))) { + gss_supported = NULL; + free(gss_host); + return 0; + } /* Check to see if the mechanism is usable before we offer it */ while (mech < gss_supported->count && !ok) { /* My DER encoding requires length<128 */ if (gss_supported->elements[mech].length < 128 && ssh_gssapi_check_mechanism(&gssctxt, - &gss_supported->elements[mech], authctxt->host)) { + &gss_supported->elements[mech], gss_host, + options.gss_client_identity)) { ok = 1; /* Mechanism works */ } else { mech++; } } + free(gss_host); + if (!ok) return 0; @@ -761,8 +842,8 @@ input_gssapi_response(int type, u_int32_t plen, void *ctxt) { Authctxt *authctxt = ctxt; Gssctxt *gssctxt; - int oidlen; - char *oidv; + u_int oidlen; + u_char *oidv; if (authctxt == NULL) fatal("input_gssapi_response: no authentication context"); @@ -875,6 +956,48 @@ input_gssapi_error(int type, u_int32_t plen, void *ctxt) free(lang); return 0; } + +int +userauth_gsskeyex(Authctxt *authctxt) +{ + Buffer b; + gss_buffer_desc gssbuf; + gss_buffer_desc mic = GSS_C_EMPTY_BUFFER; + OM_uint32 ms; + + static int attempt = 0; + if (attempt++ >= 1) + return (0); + + if (gss_kex_context == NULL) { + debug("No valid Key exchange context"); + return (0); + } + + ssh_gssapi_buildmic(&b, authctxt->server_user, authctxt->service, + "gssapi-keyex"); + + gssbuf.value = buffer_ptr(&b); + gssbuf.length = buffer_len(&b); + + if (GSS_ERROR(ssh_gssapi_sign(gss_kex_context, &gssbuf, &mic))) { + buffer_free(&b); + return (0); + } + + packet_start(SSH2_MSG_USERAUTH_REQUEST); + packet_put_cstring(authctxt->server_user); + packet_put_cstring(authctxt->service); + packet_put_cstring(authctxt->method->name); + packet_put_string(mic.value, mic.length); + packet_send(); + + buffer_free(&b); + gss_release_buffer(&ms, &mic); + + return (1); +} + #endif /* GSSAPI */ int diff --git a/sshd.c b/sshd.c index 010a2c38a..20a7a5f33 100644 --- a/sshd.c +++ b/sshd.c @@ -123,6 +123,10 @@ #include "version.h" #include "ssherr.h" +#ifdef USE_SECURITY_SESSION_API +#include +#endif + /* Re-exec fds */ #define REEXEC_DEVCRYPTO_RESERVED_FD (STDERR_FILENO + 1) #define REEXEC_STARTUP_PIPE_FD (STDERR_FILENO + 2) @@ -531,7 +535,7 @@ privsep_preauth_child(void) #ifdef GSSAPI /* Cache supported mechanism OIDs for later use */ - if (options.gss_authentication) + if (options.gss_authentication || options.gss_keyex) ssh_gssapi_prepare_supported_oids(); #endif @@ -1719,10 +1723,13 @@ main(int ac, char **av) key ? "private" : "agent", i, sshkey_ssh_name(pubkey), fp); free(fp); } +#ifndef GSSAPI + /* The GSSAPI key exchange can run without a host key */ if (!sensitive_data.have_ssh2_key) { logit("sshd: no hostkeys available -- exiting."); exit(1); } +#endif /* * Load certificates. They are stored in an array at identical @@ -1992,6 +1999,60 @@ main(int ac, char **av) remote_ip, remote_port, laddr, ssh_local_port(ssh)); free(laddr); +#ifdef USE_SECURITY_SESSION_API + /* + * Create a new security session for use by the new user login if + * the current session is the root session or we are not launched + * by inetd (eg: debugging mode or server mode). We do not + * necessarily need to create a session if we are launched from + * inetd because Panther xinetd will create a session for us. + * + * The only case where this logic will fail is if there is an + * inetd running in a non-root session which is not creating + * new sessions for us. Then all the users will end up in the + * same session (bad). + * + * When the client exits, the session will be destroyed for us + * automatically. + * + * We must create the session before any credentials are stored + * (including AFS pags, which happens a few lines below). + */ + { + OSStatus err = 0; + SecuritySessionId sid = 0; + SessionAttributeBits sattrs = 0; + + err = SessionGetInfo(callerSecuritySession, &sid, &sattrs); + if (err) + error("SessionGetInfo() failed with error %.8X", + (unsigned) err); + else + debug("Current Session ID is %.8X / Session Attributes are %.8X", + (unsigned) sid, (unsigned) sattrs); + + if (inetd_flag && !(sattrs & sessionIsRoot)) + debug("Running in inetd mode in a non-root session... " + "assuming inetd created the session for us."); + else { + debug("Creating new security session..."); + err = SessionCreate(0, sessionHasTTY | sessionIsRemote); + if (err) + error("SessionCreate() failed with error %.8X", + (unsigned) err); + + err = SessionGetInfo(callerSecuritySession, &sid, + &sattrs); + if (err) + error("SessionGetInfo() failed with error %.8X", + (unsigned) err); + else + debug("New Session ID is %.8X / Session Attributes are %.8X", + (unsigned) sid, (unsigned) sattrs); + } + } +#endif + /* * We don't want to listen forever unless the other side * successfully authenticates itself. So we set up an alarm which is @@ -2173,6 +2234,48 @@ do_ssh2_kex(void) myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = compat_pkalg_proposal( list_hostkey_types()); +#ifdef GSSAPI + { + char *orig; + char *gss = NULL; + char *newstr = NULL; + orig = myproposal[PROPOSAL_KEX_ALGS]; + + /* + * If we don't have a host key, then there's no point advertising + * the other key exchange algorithms + */ + + if (strlen(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]) == 0) + orig = NULL; + + if (options.gss_keyex) + gss = ssh_gssapi_server_mechanisms(); + else + gss = NULL; + + if (gss && orig) + xasprintf(&newstr, "%s,%s", gss, orig); + else if (gss) + newstr = gss; + else if (orig) + newstr = orig; + + /* + * If we've got GSSAPI mechanisms, then we've got the 'null' host + * key alg, but we can't tell people about it unless its the only + * host key algorithm we support + */ + if (gss && (strlen(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS])) == 0) + myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = "null"; + + if (newstr) + myproposal[PROPOSAL_KEX_ALGS] = newstr; + else + fatal("No supported key exchange algorithms"); + } +#endif + /* start key exchange */ if ((r = kex_setup(active_state, myproposal)) != 0) fatal("kex_setup: %s", ssh_err(r)); @@ -2190,6 +2293,13 @@ do_ssh2_kex(void) # endif #endif kex->kex[KEX_C25519_SHA256] = kexc25519_server; +#ifdef GSSAPI + if (options.gss_keyex) { + kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_server; + kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_server; + kex->kex[KEX_GSS_GEX_SHA1] = kexgss_server; + } +#endif kex->server = 1; kex->client_version_string=client_version_string; kex->server_version_string=server_version_string; diff --git a/sshd_config b/sshd_config index 4eb2e02e0..c01dd6561 100644 --- a/sshd_config +++ b/sshd_config @@ -70,6 +70,8 @@ AuthorizedKeysFile .ssh/authorized_keys # GSSAPI options #GSSAPIAuthentication no #GSSAPICleanupCredentials yes +#GSSAPIStrictAcceptorCheck yes +#GSSAPIKeyExchange no # Set this to 'yes' to enable PAM authentication, account processing, # and session processing. If this is enabled, PAM authentication will diff --git a/sshd_config.5 b/sshd_config.5 index ac6ccc793..3f819c76a 100644 --- a/sshd_config.5 +++ b/sshd_config.5 @@ -627,6 +627,11 @@ The default is Specifies whether user authentication based on GSSAPI is allowed. The default is .Cm no . +.It Cm GSSAPIKeyExchange +Specifies whether key exchange based on GSSAPI is allowed. GSSAPI key exchange +doesn't rely on ssh keys to verify host identity. +The default is +.Cm no . .It Cm GSSAPICleanupCredentials Specifies whether to automatically destroy the user's credentials cache on logout. @@ -646,6 +651,11 @@ machine's default store. This facility is provided to assist with operation on multi homed machines. The default is .Cm yes . +.It Cm GSSAPIStoreCredentialsOnRekey +Controls whether the user's GSSAPI credentials should be updated following a +successful connection rekeying. This option can be used to accepted renewed +or updated credentials from a compatible client. The default is +.Cm no . .It Cm HostbasedAcceptedKeyTypes Specifies the key types that will be accepted for hostbased authentication as a comma-separated pattern list. diff --git a/sshkey.c b/sshkey.c index 53a7674b5..540019898 100644 --- a/sshkey.c +++ b/sshkey.c @@ -116,6 +116,7 @@ static const struct keytype keytypes[] = { # endif /* OPENSSL_HAS_NISTP521 */ # endif /* OPENSSL_HAS_ECC */ #endif /* WITH_OPENSSL */ + { "null", "null", KEY_NULL, 0, 0, 0 }, { NULL, NULL, -1, -1, 0, 0 } }; @@ -204,7 +205,7 @@ sshkey_alg_list(int certs_only, int plain_only, int include_sigonly, char sep) const struct keytype *kt; for (kt = keytypes; kt->type != -1; kt++) { - if (kt->name == NULL) + if (kt->name == NULL || kt->type == KEY_NULL) continue; if (!include_sigonly && kt->sigonly) continue; diff --git a/sshkey.h b/sshkey.h index 1b9e42f45..f91e4a081 100644 --- a/sshkey.h +++ b/sshkey.h @@ -62,6 +62,7 @@ enum sshkey_types { KEY_DSA_CERT, KEY_ECDSA_CERT, KEY_ED25519_CERT, + KEY_NULL, KEY_UNSPEC }; -- cgit v1.2.3 From fb7c3c37876359b7a110e1386a6b7887cd2c8ca2 Mon Sep 17 00:00:00 2001 From: Colin Watson Date: Sun, 9 Feb 2014 16:09:50 +0000 Subject: Accept obsolete ssh-vulnkey configuration options These options were used as part of Debian's response to CVE-2008-0166. Nearly six years later, we no longer need to continue carrying the bulk of that patch, but we do need to avoid failing when the associated configuration options are still present. Last-Update: 2014-02-09 Patch-Name: ssh-vulnkey-compat.patch --- readconf.c | 1 + servconf.c | 1 + 2 files changed, 2 insertions(+) (limited to 'readconf.c') diff --git a/readconf.c b/readconf.c index 00d9cc302..32a729574 100644 --- a/readconf.c +++ b/readconf.c @@ -186,6 +186,7 @@ static struct { { "fallbacktorsh", oDeprecated }, { "globalknownhostsfile2", oDeprecated }, { "rhostsauthentication", oDeprecated }, + { "useblacklistedkeys", oDeprecated }, { "userknownhostsfile2", oDeprecated }, { "useroaming", oDeprecated }, { "usersh", oDeprecated }, diff --git a/servconf.c b/servconf.c index d796b7c8a..ca73f7c55 100644 --- a/servconf.c +++ b/servconf.c @@ -521,6 +521,7 @@ static struct { { "x11uselocalhost", sX11UseLocalhost, SSHCFG_ALL }, { "xauthlocation", sXAuthLocation, SSHCFG_GLOBAL }, { "strictmodes", sStrictModes, SSHCFG_GLOBAL }, + { "permitblacklistedkeys", sDeprecated, SSHCFG_GLOBAL }, { "permitemptypasswords", sEmptyPasswd, SSHCFG_ALL }, { "permituserenvironment", sPermitUserEnvironment, SSHCFG_GLOBAL }, { "uselogin", sDeprecated, SSHCFG_GLOBAL }, -- cgit v1.2.3 From 74415628b380db26961259a25dcc47c4f02e8703 Mon Sep 17 00:00:00 2001 From: Richard Kettlewell Date: Sun, 9 Feb 2014 16:09:52 +0000 Subject: Various keepalive extensions Add compatibility aliases for ProtocolKeepAlives and SetupTimeOut, supported in previous versions of Debian's OpenSSH package but since superseded by ServerAliveInterval. (We're probably stuck with this bit for compatibility.) In batch mode, default ServerAliveInterval to five minutes. Adjust documentation to match and to give some more advice on use of keepalives. Author: Ian Jackson Author: Matthew Vernon Author: Colin Watson Last-Update: 2016-12-26 Patch-Name: keepalive-extensions.patch --- readconf.c | 14 ++++++++++++-- ssh_config.5 | 21 +++++++++++++++++++-- sshd_config.5 | 3 +++ 3 files changed, 34 insertions(+), 4 deletions(-) (limited to 'readconf.c') diff --git a/readconf.c b/readconf.c index 32a729574..0b1370a8e 100644 --- a/readconf.c +++ b/readconf.c @@ -173,6 +173,7 @@ typedef enum { oStreamLocalBindMask, oStreamLocalBindUnlink, oRevokedHostKeys, oFingerprintHash, oUpdateHostkeys, oHostbasedKeyTypes, oPubkeyAcceptedKeyTypes, oProxyJump, + oProtocolKeepAlives, oSetupTimeOut, oIgnoredUnknownOption, oDeprecated, oUnsupported } OpCodes; @@ -321,6 +322,8 @@ static struct { { "pubkeyacceptedkeytypes", oPubkeyAcceptedKeyTypes }, { "ignoreunknown", oIgnoreUnknown }, { "proxyjump", oProxyJump }, + { "protocolkeepalives", oProtocolKeepAlives }, + { "setuptimeout", oSetupTimeOut }, { NULL, oBadOption } }; @@ -1417,6 +1420,8 @@ parse_keytypes: goto parse_flag; case oServerAliveInterval: + case oProtocolKeepAlives: /* Debian-specific compatibility alias */ + case oSetupTimeOut: /* Debian-specific compatibility alias */ intptr = &options->server_alive_interval; goto parse_time; @@ -2070,8 +2075,13 @@ fill_default_options(Options * options) options->rekey_interval = 0; if (options->verify_host_key_dns == -1) options->verify_host_key_dns = 0; - if (options->server_alive_interval == -1) - options->server_alive_interval = 0; + if (options->server_alive_interval == -1) { + /* in batch mode, default is 5mins */ + if (options->batch_mode == 1) + options->server_alive_interval = 300; + else + options->server_alive_interval = 0; + } if (options->server_alive_count_max == -1) options->server_alive_count_max = 3; if (options->control_master == -1) diff --git a/ssh_config.5 b/ssh_config.5 index ec60273ea..e4eaa5ae0 100644 --- a/ssh_config.5 +++ b/ssh_config.5 @@ -250,8 +250,12 @@ Valid arguments are If set to .Cm yes , passphrase/password querying will be disabled. +In addition, the +.Cm ServerAliveInterval +option will be set to 300 seconds by default (Debian-specific). This option is useful in scripts and other batch jobs where no user -is present to supply the password. +is present to supply the password, +and where it is desirable to detect a broken network swiftly. The argument must be .Cm yes or @@ -1509,7 +1513,14 @@ from the server, will send a message through the encrypted channel to request a response from the server. The default -is 0, indicating that these messages will not be sent to the server. +is 0, indicating that these messages will not be sent to the server, +or 300 if the +.Cm BatchMode +option is set (Debian-specific). +.Cm ProtocolKeepAlives +and +.Cm SetupTimeOut +are Debian-specific compatibility aliases for this option. .It Cm StreamLocalBindMask Sets the octal file creation mode mask .Pq umask @@ -1568,6 +1579,12 @@ Specifies whether the system should send TCP keepalive messages to the other side. If they are sent, death of the connection or crash of one of the machines will be properly noticed. +This option only uses TCP keepalives (as opposed to using ssh level +keepalives), so takes a long time to notice when the connection dies. +As such, you probably want +the +.Cm ServerAliveInterval +option as well. However, this means that connections will die if the route is down temporarily, and some people find it annoying. diff --git a/sshd_config.5 b/sshd_config.5 index 3f819c76a..41ec66887 100644 --- a/sshd_config.5 +++ b/sshd_config.5 @@ -1447,6 +1447,9 @@ This avoids infinitely hanging sessions. .Pp To disable TCP keepalive messages, the value should be set to .Cm no . +.Pp +This option was formerly called +.Cm KeepAlive . .It Cm TrustedUserCAKeys Specifies a file containing public keys of certificate authorities that are trusted to sign user certificates for authentication, or -- cgit v1.2.3 From 0b9c0482cbff9ce16384e4247d955676d4d77df3 Mon Sep 17 00:00:00 2001 From: Colin Watson Date: Sun, 9 Feb 2014 16:09:58 +0000 Subject: Allow harmless group-writability Allow secure files (~/.ssh/config, ~/.ssh/authorized_keys, etc.) to be group-writable, provided that the group in question contains only the file's owner. Rejected upstream for IMO incorrect reasons (e.g. a misunderstanding about the contents of gr->gr_mem). Given that per-user groups and umask 002 are the default setup in Debian (for good reasons - this makes operating in setgid directories with other groups much easier), we need to permit this by default. Bug: https://bugzilla.mindrot.org/show_bug.cgi?id=1060 Bug-Debian: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=314347 Last-Update: 2013-09-14 Patch-Name: user-group-modes.patch --- auth-rhosts.c | 6 ++---- auth.c | 9 +++----- misc.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++- misc.h | 2 ++ platform.c | 16 -------------- readconf.c | 3 +-- ssh.1 | 2 ++ ssh_config.5 | 2 ++ 8 files changed, 80 insertions(+), 29 deletions(-) (limited to 'readconf.c') diff --git a/auth-rhosts.c b/auth-rhosts.c index ecf956f06..4dccd5e6a 100644 --- a/auth-rhosts.c +++ b/auth-rhosts.c @@ -261,8 +261,7 @@ auth_rhosts2(struct passwd *pw, const char *client_user, const char *hostname, return 0; } if (options.strict_modes && - ((st.st_uid != 0 && st.st_uid != pw->pw_uid) || - (st.st_mode & 022) != 0)) { + !secure_permissions(&st, pw->pw_uid)) { logit("Rhosts authentication refused for %.100s: " "bad ownership or modes for home directory.", pw->pw_name); auth_debug_add("Rhosts authentication refused for %.100s: " @@ -288,8 +287,7 @@ auth_rhosts2(struct passwd *pw, const char *client_user, const char *hostname, * allowing access to their account by anyone. */ if (options.strict_modes && - ((st.st_uid != 0 && st.st_uid != pw->pw_uid) || - (st.st_mode & 022) != 0)) { + !secure_permissions(&st, pw->pw_uid)) { logit("Rhosts authentication refused for %.100s: bad modes for %.200s", pw->pw_name, buf); auth_debug_add("Bad file modes for %.200s", buf); diff --git a/auth.c b/auth.c index c63906873..90390724d 100644 --- a/auth.c +++ b/auth.c @@ -444,8 +444,7 @@ check_key_in_hostfiles(struct passwd *pw, Key *key, const char *host, user_hostfile = tilde_expand_filename(userfile, pw->pw_uid); if (options.strict_modes && (stat(user_hostfile, &st) == 0) && - ((st.st_uid != 0 && st.st_uid != pw->pw_uid) || - (st.st_mode & 022) != 0)) { + !secure_permissions(&st, pw->pw_uid)) { logit("Authentication refused for %.100s: " "bad owner or modes for %.200s", pw->pw_name, user_hostfile); @@ -507,8 +506,7 @@ auth_secure_path(const char *name, struct stat *stp, const char *pw_dir, snprintf(err, errlen, "%s is not a regular file", buf); return -1; } - if ((!platform_sys_dir_uid(stp->st_uid) && stp->st_uid != uid) || - (stp->st_mode & 022) != 0) { + if (!secure_permissions(stp, uid)) { snprintf(err, errlen, "bad ownership or modes for file %s", buf); return -1; @@ -523,8 +521,7 @@ auth_secure_path(const char *name, struct stat *stp, const char *pw_dir, strlcpy(buf, cp, sizeof(buf)); if (stat(buf, &st) < 0 || - (!platform_sys_dir_uid(st.st_uid) && st.st_uid != uid) || - (st.st_mode & 022) != 0) { + !secure_permissions(&st, uid)) { snprintf(err, errlen, "bad ownership or modes for directory %s", buf); return -1; diff --git a/misc.c b/misc.c index cfd32729a..6e972f563 100644 --- a/misc.c +++ b/misc.c @@ -51,8 +51,9 @@ #include #ifdef HAVE_PATHS_H # include -#include #endif +#include +#include #ifdef SSH_TUN_OPENBSD #include #endif @@ -61,6 +62,7 @@ #include "misc.h" #include "log.h" #include "ssh.h" +#include "platform.h" /* remove newline at end of string */ char * @@ -713,6 +715,71 @@ read_keyfile_line(FILE *f, const char *filename, char *buf, size_t bufsz, return -1; } +/* + * return 1 if the specified uid is a uid that may own a system directory + * otherwise 0. + */ +int +platform_sys_dir_uid(uid_t uid) +{ + if (uid == 0) + return 1; +#ifdef PLATFORM_SYS_DIR_UID + if (uid == PLATFORM_SYS_DIR_UID) + return 1; +#endif + return 0; +} + +int +secure_permissions(struct stat *st, uid_t uid) +{ + if (!platform_sys_dir_uid(st->st_uid) && st->st_uid != uid) + return 0; + if ((st->st_mode & 002) != 0) + return 0; + if ((st->st_mode & 020) != 0) { + /* If the file is group-writable, the group in question must + * have exactly one member, namely the file's owner. + * (Zero-member groups are typically used by setgid + * binaries, and are unlikely to be suitable.) + */ + struct passwd *pw; + struct group *gr; + int members = 0; + + gr = getgrgid(st->st_gid); + if (!gr) + return 0; + + /* Check primary group memberships. */ + while ((pw = getpwent()) != NULL) { + if (pw->pw_gid == gr->gr_gid) { + ++members; + if (pw->pw_uid != uid) + return 0; + } + } + endpwent(); + + pw = getpwuid(st->st_uid); + if (!pw) + return 0; + + /* Check supplementary group memberships. */ + if (gr->gr_mem[0]) { + ++members; + if (strcmp(pw->pw_name, gr->gr_mem[0]) || + gr->gr_mem[1]) + return 0; + } + + if (!members) + return 0; + } + return 1; +} + int tun_open(int tun, int mode) { diff --git a/misc.h b/misc.h index c242f9011..8b223b55e 100644 --- a/misc.h +++ b/misc.h @@ -143,6 +143,8 @@ char *read_passphrase(const char *, int); int ask_permission(const char *, ...) __attribute__((format(printf, 1, 2))); int read_keyfile_line(FILE *, const char *, char *, size_t, u_long *); +int secure_permissions(struct stat *st, uid_t uid); + #define MINIMUM(a, b) (((a) < (b)) ? (a) : (b)) #define MAXIMUM(a, b) (((a) > (b)) ? (a) : (b)) #define ROUNDUP(x, y) ((((x)+((y)-1))/(y))*(y)) diff --git a/platform.c b/platform.c index cd7bf5665..380ee3a41 100644 --- a/platform.c +++ b/platform.c @@ -197,19 +197,3 @@ platform_krb5_get_principal_name(const char *pw_name) return NULL; #endif } - -/* - * return 1 if the specified uid is a uid that may own a system directory - * otherwise 0. - */ -int -platform_sys_dir_uid(uid_t uid) -{ - if (uid == 0) - return 1; -#ifdef PLATFORM_SYS_DIR_UID - if (uid == PLATFORM_SYS_DIR_UID) - return 1; -#endif - return 0; -} diff --git a/readconf.c b/readconf.c index 0b1370a8e..70fac6824 100644 --- a/readconf.c +++ b/readconf.c @@ -1773,8 +1773,7 @@ read_config_file_depth(const char *filename, struct passwd *pw, if (fstat(fileno(f), &sb) == -1) fatal("fstat %s: %s", filename, strerror(errno)); - if (((sb.st_uid != 0 && sb.st_uid != getuid()) || - (sb.st_mode & 022) != 0)) + if (!secure_permissions(&sb, getuid())) fatal("Bad owner or permissions on %s", filename); } diff --git a/ssh.1 b/ssh.1 index 4011c65aa..feef81a54 100644 --- a/ssh.1 +++ b/ssh.1 @@ -1484,6 +1484,8 @@ The file format and configuration options are described in .Xr ssh_config 5 . Because of the potential for abuse, this file must have strict permissions: read/write for the user, and not writable by others. +It may be group-writable provided that the group in question contains only +the user. .Pp .It Pa ~/.ssh/environment Contains additional definitions for environment variables; see diff --git a/ssh_config.5 b/ssh_config.5 index e4eaa5ae0..a04e5757b 100644 --- a/ssh_config.5 +++ b/ssh_config.5 @@ -1827,6 +1827,8 @@ The format of this file is described above. This file is used by the SSH client. Because of the potential for abuse, this file must have strict permissions: read/write for the user, and not accessible by others. +It may be group-writable provided that the group in question contains only +the user. .It Pa /etc/ssh/ssh_config Systemwide configuration file. This file provides defaults for those -- cgit v1.2.3 From 78fc8282e021b0236697caedb612cab78831755f Mon Sep 17 00:00:00 2001 From: Colin Watson Date: Sun, 9 Feb 2014 16:10:18 +0000 Subject: Various Debian-specific configuration changes ssh: Enable ForwardX11Trusted, returning to earlier semantics which cause fewer problems with existing setups (http://bugs.debian.org/237021). ssh: Set 'SendEnv LANG LC_*' by default (http://bugs.debian.org/264024). ssh: Enable HashKnownHosts by default to try to limit the spread of ssh worms. ssh: Enable GSSAPIAuthentication by default. sshd: Enable PAM, disable ChallengeResponseAuthentication, and disable PrintMotd. sshd: Enable X11Forwarding. sshd: Set 'AcceptEnv LANG LC_*' by default. sshd: Change sftp subsystem path to /usr/lib/openssh/sftp-server. Document all of this. Author: Russ Allbery Forwarded: not-needed Last-Update: 2016-12-26 Patch-Name: debian-config.patch --- readconf.c | 2 +- ssh.1 | 21 +++++++++++++++++++++ ssh_config | 6 +++++- ssh_config.5 | 19 ++++++++++++++++++- sshd_config | 16 ++++++++++------ sshd_config.5 | 22 ++++++++++++++++++++++ 6 files changed, 77 insertions(+), 9 deletions(-) (limited to 'readconf.c') diff --git a/readconf.c b/readconf.c index 70fac6824..4d92d174b 100644 --- a/readconf.c +++ b/readconf.c @@ -1950,7 +1950,7 @@ fill_default_options(Options * options) if (options->forward_x11 == -1) options->forward_x11 = 0; if (options->forward_x11_trusted == -1) - options->forward_x11_trusted = 0; + options->forward_x11_trusted = 1; if (options->forward_x11_timeout == -1) options->forward_x11_timeout = 1200; /* diff --git a/ssh.1 b/ssh.1 index 22e56a7b9..6aa57c462 100644 --- a/ssh.1 +++ b/ssh.1 @@ -785,6 +785,16 @@ directive in .Xr ssh_config 5 for more information. .Pp +(Debian-specific: X11 forwarding is not subjected to X11 SECURITY extension +restrictions by default, because too many programs currently crash in this +mode. +Set the +.Cm ForwardX11Trusted +option to +.Dq no +to restore the upstream behaviour. +This may change in future depending on client-side improvements.) +.Pp .It Fl x Disables X11 forwarding. .Pp @@ -793,6 +803,17 @@ Enables trusted X11 forwarding. Trusted X11 forwardings are not subjected to the X11 SECURITY extension controls. .Pp +(Debian-specific: This option does nothing in the default configuration: it +is equivalent to +.Dq Cm ForwardX11Trusted No yes , +which is the default as described above. +Set the +.Cm ForwardX11Trusted +option to +.Dq no +to restore the upstream behaviour. +This may change in future depending on client-side improvements.) +.Pp .It Fl y Send log information using the .Xr syslog 3 diff --git a/ssh_config b/ssh_config index 4e879cd20..093c8366e 100644 --- a/ssh_config +++ b/ssh_config @@ -17,9 +17,10 @@ # list of available options, their meanings and defaults, please see the # ssh_config(5) man page. -# Host * +Host * # ForwardAgent no # ForwardX11 no +# ForwardX11Trusted yes # RhostsRSAAuthentication no # RSAAuthentication yes # PasswordAuthentication yes @@ -50,3 +51,6 @@ # VisualHostKey no # ProxyCommand ssh -q -W %h:%p gateway.example.com # RekeyLimit 1G 1h + SendEnv LANG LC_* + HashKnownHosts yes + GSSAPIAuthentication yes diff --git a/ssh_config.5 b/ssh_config.5 index 093ea8a71..fc13fa510 100644 --- a/ssh_config.5 +++ b/ssh_config.5 @@ -74,6 +74,22 @@ Since the first obtained value for each parameter is used, more host-specific declarations should be given near the beginning of the file, and general defaults at the end. .Pp +Note that the Debian +.Ic openssh-client +package sets several options as standard in +.Pa /etc/ssh/ssh_config +which are not the default in +.Xr ssh 1 : +.Pp +.Bl -bullet -offset indent -compact +.It +.Cm SendEnv No LANG LC_* +.It +.Cm HashKnownHosts No yes +.It +.Cm GSSAPIAuthentication No yes +.El +.Pp The file contains keyword-argument pairs, one per line. Lines starting with .Ql # @@ -715,11 +731,12 @@ elapsed. .It Cm ForwardX11Trusted If this option is set to .Cm yes , +(the Debian-specific default), remote X11 clients will have full access to the original X11 display. .Pp If this option is set to .Cm no -(the default), +(the upstream default), remote X11 clients will be considered untrusted and prevented from stealing or tampering with data belonging to trusted X11 clients. diff --git a/sshd_config b/sshd_config index c01dd6561..f68edf367 100644 --- a/sshd_config +++ b/sshd_config @@ -58,8 +58,9 @@ AuthorizedKeysFile .ssh/authorized_keys #PasswordAuthentication yes #PermitEmptyPasswords no -# Change to no to disable s/key passwords -#ChallengeResponseAuthentication yes +# Change to yes to enable challenge-response passwords (beware issues with +# some PAM modules and threads) +ChallengeResponseAuthentication no # Kerberos options #KerberosAuthentication no @@ -82,16 +83,16 @@ AuthorizedKeysFile .ssh/authorized_keys # If you just want the PAM account and session checks to run without # PAM authentication, then enable this but set PasswordAuthentication # and ChallengeResponseAuthentication to 'no'. -#UsePAM no +UsePAM yes #AllowAgentForwarding yes #AllowTcpForwarding yes #GatewayPorts no -#X11Forwarding no +X11Forwarding yes #X11DisplayOffset 10 #X11UseLocalhost yes #PermitTTY yes -#PrintMotd yes +PrintMotd no #PrintLastLog yes #TCPKeepAlive yes #UseLogin no @@ -109,8 +110,11 @@ AuthorizedKeysFile .ssh/authorized_keys # no default banner path #Banner none +# Allow client to pass locale environment variables +AcceptEnv LANG LC_* + # override default of no subsystems -Subsystem sftp /usr/libexec/sftp-server +Subsystem sftp /usr/lib/openssh/sftp-server # Example of overriding settings on a per-user basis #Match User anoncvs diff --git a/sshd_config.5 b/sshd_config.5 index 603c2ba7e..cc5d9fb0a 100644 --- a/sshd_config.5 +++ b/sshd_config.5 @@ -57,6 +57,28 @@ Arguments may optionally be enclosed in double quotes .Pq \&" in order to represent arguments containing spaces. .Pp +Note that the Debian +.Ic openssh-server +package sets several options as standard in +.Pa /etc/ssh/sshd_config +which are not the default in +.Xr sshd 8 : +.Pp +.Bl -bullet -offset indent -compact +.It +.Cm ChallengeResponseAuthentication No no +.It +.Cm X11Forwarding No yes +.It +.Cm PrintMotd No no +.It +.Cm AcceptEnv No LANG LC_* +.It +.Cm Subsystem No sftp /usr/lib/openssh/sftp-server +.It +.Cm UsePAM No yes +.El +.Pp The possible keywords and their meanings are as follows (note that keywords are case-insensitive and arguments are case-sensitive): -- cgit v1.2.3