Darren Tucker | 43ff44e | 2006-05-06 18:40:53 +1000 | [diff] [blame] | 1 | /* $OpenBSD: auth-krb5.c,v 1.18 2006/05/06 08:35:40 dtucker Exp $ */ |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 2 | /* |
| 3 | * Kerberos v5 authentication and ticket-passing routines. |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 4 | * |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 5 | * $FreeBSD: src/crypto/openssh/auth-krb5.c,v 1.6 2001/02/13 16:58:04 assar Exp $ |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 6 | */ |
Ben Lindstrom | eacc71b | 2002-03-22 01:22:27 +0000 | [diff] [blame] | 7 | /* |
| 8 | * Copyright (c) 2002 Daniel Kouril. All rights reserved. |
| 9 | * |
| 10 | * Redistribution and use in source and binary forms, with or without |
| 11 | * modification, are permitted provided that the following conditions |
| 12 | * are met: |
| 13 | * 1. Redistributions of source code must retain the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer. |
| 15 | * 2. Redistributions in binary form must reproduce the above copyright |
| 16 | * notice, this list of conditions and the following disclaimer in the |
| 17 | * documentation and/or other materials provided with the distribution. |
| 18 | * |
| 19 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 20 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 21 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 22 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 23 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 24 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 25 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 26 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 27 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 28 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 29 | */ |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 30 | |
| 31 | #include "includes.h" |
Ben Lindstrom | 05764b9 | 2002-03-05 01:53:02 +0000 | [diff] [blame] | 32 | |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 33 | #include "ssh.h" |
| 34 | #include "ssh1.h" |
| 35 | #include "packet.h" |
| 36 | #include "xmalloc.h" |
| 37 | #include "log.h" |
| 38 | #include "servconf.h" |
| 39 | #include "uidswap.h" |
| 40 | #include "auth.h" |
| 41 | |
| 42 | #ifdef KRB5 |
| 43 | #include <krb5.h> |
| 44 | |
| 45 | extern ServerOptions options; |
| 46 | |
| 47 | static int |
| 48 | krb5_init(void *context) |
| 49 | { |
| 50 | Authctxt *authctxt = (Authctxt *)context; |
| 51 | krb5_error_code problem; |
Damien Miller | db95e4e | 2002-02-13 16:56:44 +1100 | [diff] [blame] | 52 | |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 53 | if (authctxt->krb5_ctx == NULL) { |
| 54 | problem = krb5_init_context(&authctxt->krb5_ctx); |
| 55 | if (problem) |
| 56 | return (problem); |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 57 | } |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 58 | return (0); |
| 59 | } |
| 60 | |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 61 | int |
| 62 | auth_krb5_password(Authctxt *authctxt, const char *password) |
| 63 | { |
Damien Miller | fd4c9ee | 2002-04-13 11:04:40 +1000 | [diff] [blame] | 64 | #ifndef HEIMDAL |
| 65 | krb5_creds creds; |
| 66 | krb5_principal server; |
Damien Miller | 787b2ec | 2003-11-21 23:56:47 +1100 | [diff] [blame] | 67 | #endif |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 68 | krb5_error_code problem; |
Darren Tucker | ec0943a | 2003-08-11 22:55:36 +1000 | [diff] [blame] | 69 | krb5_ccache ccache = NULL; |
Damien Miller | 9c870f9 | 2004-04-16 22:47:55 +1000 | [diff] [blame] | 70 | int len; |
Damien Miller | db95e4e | 2002-02-13 16:56:44 +1100 | [diff] [blame] | 71 | |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 72 | temporarily_use_uid(authctxt->pw); |
Damien Miller | db95e4e | 2002-02-13 16:56:44 +1100 | [diff] [blame] | 73 | |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 74 | problem = krb5_init(authctxt); |
| 75 | if (problem) |
| 76 | goto out; |
Damien Miller | db95e4e | 2002-02-13 16:56:44 +1100 | [diff] [blame] | 77 | |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 78 | problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name, |
| 79 | &authctxt->krb5_user); |
| 80 | if (problem) |
| 81 | goto out; |
Damien Miller | db95e4e | 2002-02-13 16:56:44 +1100 | [diff] [blame] | 82 | |
Damien Miller | fd4c9ee | 2002-04-13 11:04:40 +1000 | [diff] [blame] | 83 | #ifdef HEIMDAL |
Darren Tucker | ec0943a | 2003-08-11 22:55:36 +1000 | [diff] [blame] | 84 | problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_mcc_ops, &ccache); |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 85 | if (problem) |
| 86 | goto out; |
Damien Miller | db95e4e | 2002-02-13 16:56:44 +1100 | [diff] [blame] | 87 | |
Darren Tucker | ec0943a | 2003-08-11 22:55:36 +1000 | [diff] [blame] | 88 | problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache, |
| 89 | authctxt->krb5_user); |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 90 | if (problem) |
| 91 | goto out; |
Damien Miller | db95e4e | 2002-02-13 16:56:44 +1100 | [diff] [blame] | 92 | |
| 93 | restore_uid(); |
Damien Miller | 787b2ec | 2003-11-21 23:56:47 +1100 | [diff] [blame] | 94 | |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 95 | problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user, |
Darren Tucker | ec0943a | 2003-08-11 22:55:36 +1000 | [diff] [blame] | 96 | ccache, password, 1, NULL); |
Damien Miller | 787b2ec | 2003-11-21 23:56:47 +1100 | [diff] [blame] | 97 | |
Damien Miller | db95e4e | 2002-02-13 16:56:44 +1100 | [diff] [blame] | 98 | temporarily_use_uid(authctxt->pw); |
| 99 | |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 100 | if (problem) |
| 101 | goto out; |
Darren Tucker | ec217ad | 2003-11-22 12:11:06 +1100 | [diff] [blame] | 102 | |
Darren Tucker | ec0943a | 2003-08-11 22:55:36 +1000 | [diff] [blame] | 103 | problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops, |
| 104 | &authctxt->krb5_fwd_ccache); |
| 105 | if (problem) |
| 106 | goto out; |
| 107 | |
| 108 | problem = krb5_cc_copy_cache(authctxt->krb5_ctx, ccache, |
| 109 | authctxt->krb5_fwd_ccache); |
| 110 | krb5_cc_destroy(authctxt->krb5_ctx, ccache); |
| 111 | ccache = NULL; |
| 112 | if (problem) |
| 113 | goto out; |
Damien Miller | db95e4e | 2002-02-13 16:56:44 +1100 | [diff] [blame] | 114 | |
Damien Miller | fd4c9ee | 2002-04-13 11:04:40 +1000 | [diff] [blame] | 115 | #else |
| 116 | problem = krb5_get_init_creds_password(authctxt->krb5_ctx, &creds, |
| 117 | authctxt->krb5_user, (char *)password, NULL, NULL, 0, NULL, NULL); |
| 118 | if (problem) |
| 119 | goto out; |
| 120 | |
| 121 | problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL, |
| 122 | KRB5_NT_SRV_HST, &server); |
| 123 | if (problem) |
| 124 | goto out; |
| 125 | |
| 126 | restore_uid(); |
| 127 | problem = krb5_verify_init_creds(authctxt->krb5_ctx, &creds, server, |
| 128 | NULL, NULL, NULL); |
| 129 | krb5_free_principal(authctxt->krb5_ctx, server); |
| 130 | temporarily_use_uid(authctxt->pw); |
| 131 | if (problem) |
| 132 | goto out; |
Damien Miller | 787b2ec | 2003-11-21 23:56:47 +1100 | [diff] [blame] | 133 | |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 134 | if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user, |
Damien Miller | fd4c9ee | 2002-04-13 11:04:40 +1000 | [diff] [blame] | 135 | authctxt->pw->pw_name)) { |
Ben Lindstrom | 5a6abda | 2002-06-09 19:41:48 +0000 | [diff] [blame] | 136 | problem = -1; |
Damien Miller | fd4c9ee | 2002-04-13 11:04:40 +1000 | [diff] [blame] | 137 | goto out; |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 138 | } |
Damien Miller | fd4c9ee | 2002-04-13 11:04:40 +1000 | [diff] [blame] | 139 | |
Darren Tucker | a916d14 | 2005-07-07 11:50:20 +1000 | [diff] [blame] | 140 | problem = ssh_krb5_cc_gen(authctxt->krb5_ctx, &authctxt->krb5_fwd_ccache); |
Damien Miller | fd4c9ee | 2002-04-13 11:04:40 +1000 | [diff] [blame] | 141 | if (problem) |
| 142 | goto out; |
| 143 | |
| 144 | problem = krb5_cc_initialize(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache, |
| 145 | authctxt->krb5_user); |
| 146 | if (problem) |
| 147 | goto out; |
Damien Miller | 787b2ec | 2003-11-21 23:56:47 +1100 | [diff] [blame] | 148 | |
Damien Miller | fd4c9ee | 2002-04-13 11:04:40 +1000 | [diff] [blame] | 149 | problem= krb5_cc_store_cred(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache, |
| 150 | &creds); |
| 151 | if (problem) |
| 152 | goto out; |
Damien Miller | 787b2ec | 2003-11-21 23:56:47 +1100 | [diff] [blame] | 153 | #endif |
Damien Miller | fd4c9ee | 2002-04-13 11:04:40 +1000 | [diff] [blame] | 154 | |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 155 | authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache); |
Damien Miller | db95e4e | 2002-02-13 16:56:44 +1100 | [diff] [blame] | 156 | |
Damien Miller | 9c870f9 | 2004-04-16 22:47:55 +1000 | [diff] [blame] | 157 | len = strlen(authctxt->krb5_ticket_file) + 6; |
| 158 | authctxt->krb5_ccname = xmalloc(len); |
| 159 | snprintf(authctxt->krb5_ccname, len, "FILE:%s", |
| 160 | authctxt->krb5_ticket_file); |
| 161 | |
Darren Tucker | 5614d8f | 2004-09-11 23:32:09 +1000 | [diff] [blame] | 162 | #ifdef USE_PAM |
| 163 | if (options.use_pam) |
| 164 | do_pam_putenv("KRB5CCNAME", authctxt->krb5_ccname); |
| 165 | #endif |
| 166 | |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 167 | out: |
| 168 | restore_uid(); |
Damien Miller | db95e4e | 2002-02-13 16:56:44 +1100 | [diff] [blame] | 169 | |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 170 | if (problem) { |
Darren Tucker | ec0943a | 2003-08-11 22:55:36 +1000 | [diff] [blame] | 171 | if (ccache) |
| 172 | krb5_cc_destroy(authctxt->krb5_ctx, ccache); |
| 173 | |
Damien Miller | fd4c9ee | 2002-04-13 11:04:40 +1000 | [diff] [blame] | 174 | if (authctxt->krb5_ctx != NULL && problem!=-1) |
Ben Lindstrom | b855028 | 2002-02-26 17:46:11 +0000 | [diff] [blame] | 175 | debug("Kerberos password authentication failed: %s", |
| 176 | krb5_get_err_text(authctxt->krb5_ctx, problem)); |
| 177 | else |
| 178 | debug("Kerberos password authentication failed: %d", |
| 179 | problem); |
Damien Miller | db95e4e | 2002-02-13 16:56:44 +1100 | [diff] [blame] | 180 | |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 181 | krb5_cleanup_proc(authctxt); |
Damien Miller | db95e4e | 2002-02-13 16:56:44 +1100 | [diff] [blame] | 182 | |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 183 | if (options.kerberos_or_local_passwd) |
| 184 | return (-1); |
| 185 | else |
| 186 | return (0); |
| 187 | } |
Darren Tucker | f4732f6 | 2005-11-22 19:42:42 +1100 | [diff] [blame] | 188 | return (authctxt->valid ? 1 : 0); |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 189 | } |
| 190 | |
| 191 | void |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 192 | krb5_cleanup_proc(Authctxt *authctxt) |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 193 | { |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 194 | debug("krb5_cleanup_proc called"); |
| 195 | if (authctxt->krb5_fwd_ccache) { |
| 196 | krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache); |
| 197 | authctxt->krb5_fwd_ccache = NULL; |
| 198 | } |
| 199 | if (authctxt->krb5_user) { |
| 200 | krb5_free_principal(authctxt->krb5_ctx, authctxt->krb5_user); |
| 201 | authctxt->krb5_user = NULL; |
| 202 | } |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 203 | if (authctxt->krb5_ctx) { |
| 204 | krb5_free_context(authctxt->krb5_ctx); |
| 205 | authctxt->krb5_ctx = NULL; |
| 206 | } |
| 207 | } |
| 208 | |
Darren Tucker | a916d14 | 2005-07-07 11:50:20 +1000 | [diff] [blame] | 209 | #ifndef HEIMDAL |
| 210 | krb5_error_code |
| 211 | ssh_krb5_cc_gen(krb5_context ctx, krb5_ccache *ccache) { |
| 212 | int tmpfd, ret; |
| 213 | char ccname[40]; |
| 214 | mode_t old_umask; |
| 215 | |
| 216 | ret = snprintf(ccname, sizeof(ccname), |
| 217 | "FILE:/tmp/krb5cc_%d_XXXXXXXXXX", geteuid()); |
Darren Tucker | 618db97 | 2005-11-10 14:43:11 +1100 | [diff] [blame] | 218 | if (ret < 0 || (size_t)ret >= sizeof(ccname)) |
Darren Tucker | a83f261 | 2005-07-07 20:09:35 +1000 | [diff] [blame] | 219 | return ENOMEM; |
Darren Tucker | a916d14 | 2005-07-07 11:50:20 +1000 | [diff] [blame] | 220 | |
| 221 | old_umask = umask(0177); |
| 222 | tmpfd = mkstemp(ccname + strlen("FILE:")); |
| 223 | umask(old_umask); |
| 224 | if (tmpfd == -1) { |
| 225 | logit("mkstemp(): %.100s", strerror(errno)); |
| 226 | return errno; |
| 227 | } |
| 228 | |
| 229 | if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) { |
| 230 | logit("fchmod(): %.100s", strerror(errno)); |
| 231 | close(tmpfd); |
| 232 | return errno; |
| 233 | } |
| 234 | close(tmpfd); |
| 235 | |
| 236 | return (krb5_cc_resolve(ctx, ccname, ccache)); |
| 237 | } |
| 238 | #endif /* !HEIMDAL */ |
Damien Miller | 964fed5 | 2001-09-25 12:58:23 +1000 | [diff] [blame] | 239 | #endif /* KRB5 */ |