blob: b56f43a92388f6a82e952136907866180bab3feb [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 Miller61b05cf2001-11-14 00:02:10 +11005 * $OpenBSD: auth-krb5.c,v 1.2 2001/11/12 01:47:09 dugsong Exp $
Damien Miller964fed52001-09-25 12:58:23 +10006 */
7
8#include "includes.h"
9#include "ssh.h"
10#include "ssh1.h"
11#include "packet.h"
12#include "xmalloc.h"
13#include "log.h"
14#include "servconf.h"
15#include "uidswap.h"
16#include "auth.h"
17
18#ifdef KRB5
19#include <krb5.h>
20
21extern ServerOptions options;
22
23static int
24krb5_init(void *context)
25{
26 Authctxt *authctxt = (Authctxt *)context;
27 krb5_error_code problem;
28 static int cleanup_registered = 0;
29
30 if (authctxt->krb5_ctx == NULL) {
31 problem = krb5_init_context(&authctxt->krb5_ctx);
32 if (problem)
33 return (problem);
34 krb5_init_ets(authctxt->krb5_ctx);
35 }
36 if (!cleanup_registered) {
37 fatal_add_cleanup(krb5_cleanup_proc, authctxt);
38 cleanup_registered = 1;
39 }
40 return (0);
41}
42
43/*
44 * Try krb5 authentication. server_user is passed for logging purposes
45 * only, in auth is received ticket, in client is returned principal
46 * from the ticket
47 */
48int
49auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client)
50{
51 krb5_error_code problem;
52 krb5_principal server;
53 krb5_data reply;
54 krb5_ticket *ticket;
Damien Miller61b05cf2001-11-14 00:02:10 +110055 int fd, ret;
56
57 ret = 0;
Damien Miller964fed52001-09-25 12:58:23 +100058 server = NULL;
59 ticket = NULL;
60 reply.length = 0;
61
62 problem = krb5_init(authctxt);
63 if (problem)
64 goto err;
65
66 problem = krb5_auth_con_init(authctxt->krb5_ctx,
67 &authctxt->krb5_auth_ctx);
68 if (problem)
69 goto err;
70
71 fd = packet_get_connection_in();
72 problem = krb5_auth_con_setaddrs_from_fd(authctxt->krb5_ctx,
73 authctxt->krb5_auth_ctx, &fd);
74 if (problem)
75 goto err;
76
77 problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL ,
78 KRB5_NT_SRV_HST, &server);
79 if (problem)
80 goto err;
81
82 problem = krb5_rd_req(authctxt->krb5_ctx, &authctxt->krb5_auth_ctx,
83 auth, server, NULL, NULL, &ticket);
84 if (problem)
85 goto err;
86
87 problem = krb5_copy_principal(authctxt->krb5_ctx, ticket->client,
88 &authctxt->krb5_user);
89 if (problem)
90 goto err;
91
92 /* if client wants mutual auth */
93 problem = krb5_mk_rep(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
94 &reply);
95 if (problem)
96 goto err;
97
98 /* Check .k5login authorization now. */
99 if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user,
100 authctxt->pw->pw_name))
101 goto err;
102
103 if (client)
104 krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user,
105 client);
106
107 packet_start(SSH_SMSG_AUTH_KERBEROS_RESPONSE);
108 packet_put_string((char *) reply.data, reply.length);
109 packet_send();
110 packet_write_wait();
Damien Miller61b05cf2001-11-14 00:02:10 +1100111
112 ret = 1;
Damien Miller964fed52001-09-25 12:58:23 +1000113 err:
114 if (server)
115 krb5_free_principal(authctxt->krb5_ctx, server);
116 if (ticket)
117 krb5_free_ticket(authctxt->krb5_ctx, ticket);
118 if (reply.length)
119 xfree(reply.data);
120
Damien Miller61b05cf2001-11-14 00:02:10 +1100121 if (problem)
Damien Miller964fed52001-09-25 12:58:23 +1000122 debug("Kerberos v5 authentication failed: %s",
123 krb5_get_err_text(authctxt->krb5_ctx, problem));
Damien Miller61b05cf2001-11-14 00:02:10 +1100124
125 return (ret);
Damien Miller964fed52001-09-25 12:58:23 +1000126}
127
128int
129auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt)
130{
131 krb5_error_code problem;
132 krb5_ccache ccache = NULL;
133 char *pname;
134
135 if (authctxt->pw == NULL || authctxt->krb5_user == NULL)
136 return (0);
137
138 temporarily_use_uid(authctxt->pw);
139
140 problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops, &ccache);
141 if (problem)
142 goto fail;
143
144 problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache,
145 authctxt->krb5_user);
146 if (problem)
147 goto fail;
148
149 problem = krb5_rd_cred2(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
150 ccache, tgt);
151 if (problem)
152 goto fail;
153
154 authctxt->krb5_fwd_ccache = ccache;
155 ccache = NULL;
156
157 authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
158
159 problem = krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user,
160 &pname);
161 if (problem)
162 goto fail;
163
164 debug("Kerberos v5 TGT accepted (%s)", pname);
165
166 restore_uid();
167
168 return (1);
169
170 fail:
171 if (problem)
172 debug("Kerberos v5 TGT passing failed: %s",
173 krb5_get_err_text(authctxt->krb5_ctx, problem));
174 if (ccache)
175 krb5_cc_destroy(authctxt->krb5_ctx, ccache);
176
177 restore_uid();
178
179 return (0);
180}
181
182int
183auth_krb5_password(Authctxt *authctxt, const char *password)
184{
185 krb5_error_code problem;
186
187 if (authctxt->pw == NULL)
188 return (0);
189
190 temporarily_use_uid(authctxt->pw);
191
192 problem = krb5_init(authctxt);
193 if (problem)
194 goto out;
195
196 problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name,
197 &authctxt->krb5_user);
198 if (problem)
199 goto out;
200
201 problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_mcc_ops,
202 &authctxt->krb5_fwd_ccache);
203 if (problem)
204 goto out;
205
206 problem = krb5_cc_initialize(authctxt->krb5_ctx,
207 authctxt->krb5_fwd_ccache, authctxt->krb5_user);
208 if (problem)
209 goto out;
210
211 problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user,
212 authctxt->krb5_fwd_ccache, password, 1, NULL);
213 if (problem)
214 goto out;
215
216 authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
217
218 out:
219 restore_uid();
220
221 if (problem) {
222 debug("Kerberos password authentication failed: %s",
223 krb5_get_err_text(authctxt->krb5_ctx, problem));
224
225 krb5_cleanup_proc(authctxt);
226
227 if (options.kerberos_or_local_passwd)
228 return (-1);
229 else
230 return (0);
231 }
232 return (1);
233}
234
235void
236krb5_cleanup_proc(void *context)
237{
238 Authctxt *authctxt = (Authctxt *)context;
239
240 debug("krb5_cleanup_proc called");
241 if (authctxt->krb5_fwd_ccache) {
242 krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
243 authctxt->krb5_fwd_ccache = NULL;
244 }
245 if (authctxt->krb5_user) {
246 krb5_free_principal(authctxt->krb5_ctx, authctxt->krb5_user);
247 authctxt->krb5_user = NULL;
248 }
249 if (authctxt->krb5_auth_ctx) {
250 krb5_auth_con_free(authctxt->krb5_ctx,
251 authctxt->krb5_auth_ctx);
252 authctxt->krb5_auth_ctx = NULL;
253 }
254 if (authctxt->krb5_ctx) {
255 krb5_free_context(authctxt->krb5_ctx);
256 authctxt->krb5_ctx = NULL;
257 }
258}
259
260#endif /* KRB5 */