blob: 2da0669ae629f7e1153a970f03447e0853960c7c [file] [log] [blame]
Damien Miller964fed52001-09-25 12:58:23 +10001/*
2 * Kerberos v5 authentication and ticket-passing routines.
3 *
4 * $FreeBSD: src/crypto/openssh/auth-krb5.c,v 1.6 2001/02/13 16:58:04 assar Exp $
Damien Miller964fed52001-09-25 12:58:23 +10005 */
6
7#include "includes.h"
Ben Lindstrom05764b92002-03-05 01:53:02 +00008RCSID("$OpenBSD: auth-krb5.c,v 1.6 2002/03/04 17:27:39 stevesk Exp $");
9
Damien Miller964fed52001-09-25 12:58:23 +100010#include "ssh.h"
11#include "ssh1.h"
12#include "packet.h"
13#include "xmalloc.h"
14#include "log.h"
15#include "servconf.h"
16#include "uidswap.h"
17#include "auth.h"
18
19#ifdef KRB5
20#include <krb5.h>
21
22extern ServerOptions options;
23
24static int
25krb5_init(void *context)
26{
27 Authctxt *authctxt = (Authctxt *)context;
28 krb5_error_code problem;
29 static int cleanup_registered = 0;
Damien Millerdb95e4e2002-02-13 16:56:44 +110030
Damien Miller964fed52001-09-25 12:58:23 +100031 if (authctxt->krb5_ctx == NULL) {
32 problem = krb5_init_context(&authctxt->krb5_ctx);
33 if (problem)
34 return (problem);
35 krb5_init_ets(authctxt->krb5_ctx);
36 }
37 if (!cleanup_registered) {
38 fatal_add_cleanup(krb5_cleanup_proc, authctxt);
39 cleanup_registered = 1;
40 }
41 return (0);
42}
43
44/*
45 * Try krb5 authentication. server_user is passed for logging purposes
46 * only, in auth is received ticket, in client is returned principal
47 * from the ticket
48 */
Damien Millerdb95e4e2002-02-13 16:56:44 +110049int
Damien Miller964fed52001-09-25 12:58:23 +100050auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client)
51{
52 krb5_error_code problem;
53 krb5_principal server;
54 krb5_data reply;
55 krb5_ticket *ticket;
Damien Miller61b05cf2001-11-14 00:02:10 +110056 int fd, ret;
57
58 ret = 0;
Damien Miller964fed52001-09-25 12:58:23 +100059 server = NULL;
60 ticket = NULL;
61 reply.length = 0;
Damien Millerdb95e4e2002-02-13 16:56:44 +110062
Damien Miller964fed52001-09-25 12:58:23 +100063 problem = krb5_init(authctxt);
Damien Millerdb95e4e2002-02-13 16:56:44 +110064 if (problem)
Damien Miller964fed52001-09-25 12:58:23 +100065 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +110066
Damien Miller964fed52001-09-25 12:58:23 +100067 problem = krb5_auth_con_init(authctxt->krb5_ctx,
68 &authctxt->krb5_auth_ctx);
69 if (problem)
70 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +110071
Damien Miller964fed52001-09-25 12:58:23 +100072 fd = packet_get_connection_in();
73 problem = krb5_auth_con_setaddrs_from_fd(authctxt->krb5_ctx,
74 authctxt->krb5_auth_ctx, &fd);
75 if (problem)
76 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +110077
Damien Miller964fed52001-09-25 12:58:23 +100078 problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL ,
79 KRB5_NT_SRV_HST, &server);
80 if (problem)
81 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +110082
Damien Miller964fed52001-09-25 12:58:23 +100083 problem = krb5_rd_req(authctxt->krb5_ctx, &authctxt->krb5_auth_ctx,
84 auth, server, NULL, NULL, &ticket);
85 if (problem)
86 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +110087
Damien Miller964fed52001-09-25 12:58:23 +100088 problem = krb5_copy_principal(authctxt->krb5_ctx, ticket->client,
89 &authctxt->krb5_user);
90 if (problem)
91 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +110092
Damien Miller964fed52001-09-25 12:58:23 +100093 /* if client wants mutual auth */
94 problem = krb5_mk_rep(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
95 &reply);
96 if (problem)
97 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +110098
Damien Miller964fed52001-09-25 12:58:23 +100099 /* Check .k5login authorization now. */
100 if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user,
101 authctxt->pw->pw_name))
102 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100103
Damien Miller964fed52001-09-25 12:58:23 +1000104 if (client)
105 krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user,
106 client);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100107
Damien Miller964fed52001-09-25 12:58:23 +1000108 packet_start(SSH_SMSG_AUTH_KERBEROS_RESPONSE);
109 packet_put_string((char *) reply.data, reply.length);
110 packet_send();
111 packet_write_wait();
Damien Miller61b05cf2001-11-14 00:02:10 +1100112
113 ret = 1;
Damien Miller964fed52001-09-25 12:58:23 +1000114 err:
115 if (server)
116 krb5_free_principal(authctxt->krb5_ctx, server);
117 if (ticket)
118 krb5_free_ticket(authctxt->krb5_ctx, ticket);
119 if (reply.length)
120 xfree(reply.data);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100121
Ben Lindstromb8550282002-02-26 17:46:11 +0000122 if (problem) {
123 if (authctxt->krb5_ctx != NULL)
124 debug("Kerberos v5 authentication failed: %s",
125 krb5_get_err_text(authctxt->krb5_ctx, problem));
126 else
127 debug("Kerberos v5 authentication failed: %d",
128 problem);
129 }
Damien Miller61b05cf2001-11-14 00:02:10 +1100130
131 return (ret);
Damien Miller964fed52001-09-25 12:58:23 +1000132}
133
134int
135auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt)
136{
137 krb5_error_code problem;
138 krb5_ccache ccache = NULL;
139 char *pname;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100140
Damien Miller964fed52001-09-25 12:58:23 +1000141 if (authctxt->pw == NULL || authctxt->krb5_user == NULL)
142 return (0);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100143
Damien Miller964fed52001-09-25 12:58:23 +1000144 temporarily_use_uid(authctxt->pw);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100145
Damien Miller964fed52001-09-25 12:58:23 +1000146 problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops, &ccache);
147 if (problem)
148 goto fail;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100149
Damien Miller964fed52001-09-25 12:58:23 +1000150 problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache,
151 authctxt->krb5_user);
152 if (problem)
153 goto fail;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100154
Damien Miller964fed52001-09-25 12:58:23 +1000155 problem = krb5_rd_cred2(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
156 ccache, tgt);
157 if (problem)
158 goto fail;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100159
Damien Miller964fed52001-09-25 12:58:23 +1000160 authctxt->krb5_fwd_ccache = ccache;
161 ccache = NULL;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100162
Damien Miller964fed52001-09-25 12:58:23 +1000163 authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100164
Damien Miller964fed52001-09-25 12:58:23 +1000165 problem = krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user,
166 &pname);
167 if (problem)
168 goto fail;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100169
Damien Miller964fed52001-09-25 12:58:23 +1000170 debug("Kerberos v5 TGT accepted (%s)", pname);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100171
Damien Miller964fed52001-09-25 12:58:23 +1000172 restore_uid();
Damien Millerdb95e4e2002-02-13 16:56:44 +1100173
Damien Miller964fed52001-09-25 12:58:23 +1000174 return (1);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100175
Damien Miller964fed52001-09-25 12:58:23 +1000176 fail:
177 if (problem)
178 debug("Kerberos v5 TGT passing failed: %s",
179 krb5_get_err_text(authctxt->krb5_ctx, problem));
180 if (ccache)
181 krb5_cc_destroy(authctxt->krb5_ctx, ccache);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100182
Damien Miller964fed52001-09-25 12:58:23 +1000183 restore_uid();
Damien Millerdb95e4e2002-02-13 16:56:44 +1100184
Damien Miller964fed52001-09-25 12:58:23 +1000185 return (0);
186}
187
188int
189auth_krb5_password(Authctxt *authctxt, const char *password)
190{
191 krb5_error_code problem;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100192
Damien Miller964fed52001-09-25 12:58:23 +1000193 if (authctxt->pw == NULL)
194 return (0);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100195
Damien Miller964fed52001-09-25 12:58:23 +1000196 temporarily_use_uid(authctxt->pw);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100197
Damien Miller964fed52001-09-25 12:58:23 +1000198 problem = krb5_init(authctxt);
199 if (problem)
200 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100201
Damien Miller964fed52001-09-25 12:58:23 +1000202 problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name,
203 &authctxt->krb5_user);
204 if (problem)
205 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100206
Damien Miller964fed52001-09-25 12:58:23 +1000207 problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_mcc_ops,
208 &authctxt->krb5_fwd_ccache);
209 if (problem)
210 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100211
Damien Miller964fed52001-09-25 12:58:23 +1000212 problem = krb5_cc_initialize(authctxt->krb5_ctx,
213 authctxt->krb5_fwd_ccache, authctxt->krb5_user);
214 if (problem)
215 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100216
217 restore_uid();
Damien Miller964fed52001-09-25 12:58:23 +1000218 problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user,
219 authctxt->krb5_fwd_ccache, password, 1, NULL);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100220 temporarily_use_uid(authctxt->pw);
221
Damien Miller964fed52001-09-25 12:58:23 +1000222 if (problem)
223 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100224
Damien Miller964fed52001-09-25 12:58:23 +1000225 authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100226
Damien Miller964fed52001-09-25 12:58:23 +1000227 out:
228 restore_uid();
Damien Millerdb95e4e2002-02-13 16:56:44 +1100229
Damien Miller964fed52001-09-25 12:58:23 +1000230 if (problem) {
Ben Lindstromb8550282002-02-26 17:46:11 +0000231 if (authctxt->krb5_ctx != NULL)
232 debug("Kerberos password authentication failed: %s",
233 krb5_get_err_text(authctxt->krb5_ctx, problem));
234 else
235 debug("Kerberos password authentication failed: %d",
236 problem);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100237
Damien Miller964fed52001-09-25 12:58:23 +1000238 krb5_cleanup_proc(authctxt);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100239
Damien Miller964fed52001-09-25 12:58:23 +1000240 if (options.kerberos_or_local_passwd)
241 return (-1);
242 else
243 return (0);
244 }
245 return (1);
246}
247
248void
249krb5_cleanup_proc(void *context)
250{
251 Authctxt *authctxt = (Authctxt *)context;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100252
Damien Miller964fed52001-09-25 12:58:23 +1000253 debug("krb5_cleanup_proc called");
254 if (authctxt->krb5_fwd_ccache) {
255 krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
256 authctxt->krb5_fwd_ccache = NULL;
257 }
258 if (authctxt->krb5_user) {
259 krb5_free_principal(authctxt->krb5_ctx, authctxt->krb5_user);
260 authctxt->krb5_user = NULL;
261 }
262 if (authctxt->krb5_auth_ctx) {
263 krb5_auth_con_free(authctxt->krb5_ctx,
264 authctxt->krb5_auth_ctx);
265 authctxt->krb5_auth_ctx = NULL;
266 }
267 if (authctxt->krb5_ctx) {
268 krb5_free_context(authctxt->krb5_ctx);
269 authctxt->krb5_ctx = NULL;
270 }
271}
272
273#endif /* KRB5 */