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aa9f6a6e | 1 | /* |
2 | * Kerberos v5 authentication and ticket-passing routines. | |
762715ce | 3 | * |
aa9f6a6e | 4 | * $FreeBSD: src/crypto/openssh/auth-krb5.c,v 1.6 2001/02/13 16:58:04 assar Exp $ |
aa9f6a6e | 5 | */ |
bb15f28b | 6 | /* |
7 | * Copyright (c) 2002 Daniel Kouril. All rights reserved. | |
8 | * | |
9 | * Redistribution and use in source and binary forms, with or without | |
10 | * modification, are permitted provided that the following conditions | |
11 | * are met: | |
12 | * 1. Redistributions of source code must retain the above copyright | |
13 | * notice, this list of conditions and the following disclaimer. | |
14 | * 2. Redistributions in binary form must reproduce the above copyright | |
15 | * notice, this list of conditions and the following disclaimer in the | |
16 | * documentation and/or other materials provided with the distribution. | |
17 | * | |
18 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
19 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
20 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
21 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
22 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
23 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
24 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
25 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
26 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
27 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
28 | */ | |
aa9f6a6e | 29 | |
30 | #include "includes.h" | |
762715ce | 31 | RCSID("$OpenBSD: auth-krb5.c,v 1.8 2002/03/19 10:49:35 markus Exp $"); |
93c3b6de | 32 | |
aa9f6a6e | 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; | |
52 | static int cleanup_registered = 0; | |
a0105740 | 53 | |
aa9f6a6e | 54 | if (authctxt->krb5_ctx == NULL) { |
55 | problem = krb5_init_context(&authctxt->krb5_ctx); | |
56 | if (problem) | |
57 | return (problem); | |
58 | krb5_init_ets(authctxt->krb5_ctx); | |
59 | } | |
60 | if (!cleanup_registered) { | |
61 | fatal_add_cleanup(krb5_cleanup_proc, authctxt); | |
62 | cleanup_registered = 1; | |
63 | } | |
64 | return (0); | |
65 | } | |
66 | ||
67 | /* | |
68 | * Try krb5 authentication. server_user is passed for logging purposes | |
69 | * only, in auth is received ticket, in client is returned principal | |
70 | * from the ticket | |
71 | */ | |
a0105740 | 72 | int |
aa9f6a6e | 73 | auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client) |
74 | { | |
75 | krb5_error_code problem; | |
76 | krb5_principal server; | |
77 | krb5_data reply; | |
78 | krb5_ticket *ticket; | |
ede8cea6 | 79 | int fd, ret; |
80 | ||
81 | ret = 0; | |
aa9f6a6e | 82 | server = NULL; |
83 | ticket = NULL; | |
84 | reply.length = 0; | |
a0105740 | 85 | |
aa9f6a6e | 86 | problem = krb5_init(authctxt); |
a0105740 | 87 | if (problem) |
aa9f6a6e | 88 | goto err; |
a0105740 | 89 | |
aa9f6a6e | 90 | problem = krb5_auth_con_init(authctxt->krb5_ctx, |
91 | &authctxt->krb5_auth_ctx); | |
92 | if (problem) | |
93 | goto err; | |
a0105740 | 94 | |
aa9f6a6e | 95 | fd = packet_get_connection_in(); |
96 | problem = krb5_auth_con_setaddrs_from_fd(authctxt->krb5_ctx, | |
97 | authctxt->krb5_auth_ctx, &fd); | |
98 | if (problem) | |
99 | goto err; | |
a0105740 | 100 | |
aa9f6a6e | 101 | problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL , |
102 | KRB5_NT_SRV_HST, &server); | |
103 | if (problem) | |
104 | goto err; | |
a0105740 | 105 | |
aa9f6a6e | 106 | problem = krb5_rd_req(authctxt->krb5_ctx, &authctxt->krb5_auth_ctx, |
107 | auth, server, NULL, NULL, &ticket); | |
108 | if (problem) | |
109 | goto err; | |
a0105740 | 110 | |
aa9f6a6e | 111 | problem = krb5_copy_principal(authctxt->krb5_ctx, ticket->client, |
112 | &authctxt->krb5_user); | |
113 | if (problem) | |
114 | goto err; | |
a0105740 | 115 | |
aa9f6a6e | 116 | /* if client wants mutual auth */ |
117 | problem = krb5_mk_rep(authctxt->krb5_ctx, authctxt->krb5_auth_ctx, | |
118 | &reply); | |
119 | if (problem) | |
120 | goto err; | |
a0105740 | 121 | |
aa9f6a6e | 122 | /* Check .k5login authorization now. */ |
123 | if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user, | |
124 | authctxt->pw->pw_name)) | |
125 | goto err; | |
a0105740 | 126 | |
aa9f6a6e | 127 | if (client) |
128 | krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user, | |
129 | client); | |
a0105740 | 130 | |
aa9f6a6e | 131 | packet_start(SSH_SMSG_AUTH_KERBEROS_RESPONSE); |
132 | packet_put_string((char *) reply.data, reply.length); | |
133 | packet_send(); | |
134 | packet_write_wait(); | |
ede8cea6 | 135 | |
136 | ret = 1; | |
aa9f6a6e | 137 | err: |
138 | if (server) | |
139 | krb5_free_principal(authctxt->krb5_ctx, server); | |
140 | if (ticket) | |
141 | krb5_free_ticket(authctxt->krb5_ctx, ticket); | |
142 | if (reply.length) | |
143 | xfree(reply.data); | |
a0105740 | 144 | |
c12337d9 | 145 | if (problem) { |
146 | if (authctxt->krb5_ctx != NULL) | |
147 | debug("Kerberos v5 authentication failed: %s", | |
148 | krb5_get_err_text(authctxt->krb5_ctx, problem)); | |
149 | else | |
150 | debug("Kerberos v5 authentication failed: %d", | |
151 | problem); | |
152 | } | |
ede8cea6 | 153 | |
154 | return (ret); | |
aa9f6a6e | 155 | } |
156 | ||
157 | int | |
158 | auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt) | |
159 | { | |
160 | krb5_error_code problem; | |
161 | krb5_ccache ccache = NULL; | |
162 | char *pname; | |
a0105740 | 163 | |
aa9f6a6e | 164 | if (authctxt->pw == NULL || authctxt->krb5_user == NULL) |
165 | return (0); | |
a0105740 | 166 | |
aa9f6a6e | 167 | temporarily_use_uid(authctxt->pw); |
a0105740 | 168 | |
aa9f6a6e | 169 | problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops, &ccache); |
170 | if (problem) | |
171 | goto fail; | |
a0105740 | 172 | |
aa9f6a6e | 173 | problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache, |
174 | authctxt->krb5_user); | |
175 | if (problem) | |
176 | goto fail; | |
a0105740 | 177 | |
aa9f6a6e | 178 | problem = krb5_rd_cred2(authctxt->krb5_ctx, authctxt->krb5_auth_ctx, |
179 | ccache, tgt); | |
180 | if (problem) | |
181 | goto fail; | |
a0105740 | 182 | |
aa9f6a6e | 183 | authctxt->krb5_fwd_ccache = ccache; |
184 | ccache = NULL; | |
a0105740 | 185 | |
aa9f6a6e | 186 | authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache); |
a0105740 | 187 | |
aa9f6a6e | 188 | problem = krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user, |
189 | &pname); | |
190 | if (problem) | |
191 | goto fail; | |
a0105740 | 192 | |
aa9f6a6e | 193 | debug("Kerberos v5 TGT accepted (%s)", pname); |
a0105740 | 194 | |
aa9f6a6e | 195 | restore_uid(); |
a0105740 | 196 | |
aa9f6a6e | 197 | return (1); |
a0105740 | 198 | |
aa9f6a6e | 199 | fail: |
200 | if (problem) | |
201 | debug("Kerberos v5 TGT passing failed: %s", | |
202 | krb5_get_err_text(authctxt->krb5_ctx, problem)); | |
203 | if (ccache) | |
204 | krb5_cc_destroy(authctxt->krb5_ctx, ccache); | |
a0105740 | 205 | |
aa9f6a6e | 206 | restore_uid(); |
a0105740 | 207 | |
aa9f6a6e | 208 | return (0); |
209 | } | |
210 | ||
211 | int | |
212 | auth_krb5_password(Authctxt *authctxt, const char *password) | |
213 | { | |
214 | krb5_error_code problem; | |
a0105740 | 215 | |
aa9f6a6e | 216 | if (authctxt->pw == NULL) |
217 | return (0); | |
a0105740 | 218 | |
aa9f6a6e | 219 | temporarily_use_uid(authctxt->pw); |
a0105740 | 220 | |
aa9f6a6e | 221 | problem = krb5_init(authctxt); |
222 | if (problem) | |
223 | goto out; | |
a0105740 | 224 | |
aa9f6a6e | 225 | problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name, |
226 | &authctxt->krb5_user); | |
227 | if (problem) | |
228 | goto out; | |
a0105740 | 229 | |
aa9f6a6e | 230 | problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_mcc_ops, |
231 | &authctxt->krb5_fwd_ccache); | |
232 | if (problem) | |
233 | goto out; | |
a0105740 | 234 | |
aa9f6a6e | 235 | problem = krb5_cc_initialize(authctxt->krb5_ctx, |
236 | authctxt->krb5_fwd_ccache, authctxt->krb5_user); | |
237 | if (problem) | |
238 | goto out; | |
a0105740 | 239 | |
240 | restore_uid(); | |
aa9f6a6e | 241 | problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user, |
242 | authctxt->krb5_fwd_ccache, password, 1, NULL); | |
a0105740 | 243 | temporarily_use_uid(authctxt->pw); |
244 | ||
aa9f6a6e | 245 | if (problem) |
246 | goto out; | |
a0105740 | 247 | |
aa9f6a6e | 248 | authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache); |
a0105740 | 249 | |
aa9f6a6e | 250 | out: |
251 | restore_uid(); | |
a0105740 | 252 | |
aa9f6a6e | 253 | if (problem) { |
c12337d9 | 254 | if (authctxt->krb5_ctx != NULL) |
255 | debug("Kerberos password authentication failed: %s", | |
256 | krb5_get_err_text(authctxt->krb5_ctx, problem)); | |
257 | else | |
258 | debug("Kerberos password authentication failed: %d", | |
259 | problem); | |
a0105740 | 260 | |
aa9f6a6e | 261 | krb5_cleanup_proc(authctxt); |
a0105740 | 262 | |
aa9f6a6e | 263 | if (options.kerberos_or_local_passwd) |
264 | return (-1); | |
265 | else | |
266 | return (0); | |
267 | } | |
268 | return (1); | |
269 | } | |
270 | ||
271 | void | |
272 | krb5_cleanup_proc(void *context) | |
273 | { | |
274 | Authctxt *authctxt = (Authctxt *)context; | |
a0105740 | 275 | |
aa9f6a6e | 276 | debug("krb5_cleanup_proc called"); |
277 | if (authctxt->krb5_fwd_ccache) { | |
278 | krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache); | |
279 | authctxt->krb5_fwd_ccache = NULL; | |
280 | } | |
281 | if (authctxt->krb5_user) { | |
282 | krb5_free_principal(authctxt->krb5_ctx, authctxt->krb5_user); | |
283 | authctxt->krb5_user = NULL; | |
284 | } | |
285 | if (authctxt->krb5_auth_ctx) { | |
286 | krb5_auth_con_free(authctxt->krb5_ctx, | |
287 | authctxt->krb5_auth_ctx); | |
288 | authctxt->krb5_auth_ctx = NULL; | |
289 | } | |
290 | if (authctxt->krb5_ctx) { | |
291 | krb5_free_context(authctxt->krb5_ctx); | |
292 | authctxt->krb5_ctx = NULL; | |
293 | } | |
294 | } | |
295 | ||
296 | #endif /* KRB5 */ |