blob: 8d75ee5c7bb28d3fda6fda89d94cee913034b9d2 [file] [log] [blame]
Damien Millera66cf682006-03-26 00:05:23 +11001/* $OpenBSD: gss-genr.c,v 1.7 2006/03/20 04:07:49 djm Exp $ */
Darren Tucker0efd1552003-08-26 11:49:55 +10002
3/*
4 * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include "includes.h"
28
29#ifdef GSSAPI
30
31#include "xmalloc.h"
32#include "bufaux.h"
Darren Tucker0efd1552003-08-26 11:49:55 +100033#include "log.h"
Damien Miller0425d402003-11-17 22:18:21 +110034#include "ssh2.h"
Darren Tucker0efd1552003-08-26 11:49:55 +100035
36#include "ssh-gss.h"
37
Damien Miller0425d402003-11-17 22:18:21 +110038extern u_char *session_id2;
39extern u_int session_id2_len;
Darren Tucker0efd1552003-08-26 11:49:55 +100040
41/* Check that the OID in a data stream matches that in the context */
42int
43ssh_gssapi_check_oid(Gssctxt *ctx, void *data, size_t len)
44{
45 return (ctx != NULL && ctx->oid != GSS_C_NO_OID &&
46 ctx->oid->length == len &&
47 memcmp(ctx->oid->elements, data, len) == 0);
48}
49
50/* Set the contexts OID from a data stream */
51void
52ssh_gssapi_set_oid_data(Gssctxt *ctx, void *data, size_t len)
53{
54 if (ctx->oid != GSS_C_NO_OID) {
55 xfree(ctx->oid->elements);
56 xfree(ctx->oid);
57 }
58 ctx->oid = xmalloc(sizeof(gss_OID_desc));
59 ctx->oid->length = len;
60 ctx->oid->elements = xmalloc(len);
61 memcpy(ctx->oid->elements, data, len);
62}
63
64/* Set the contexts OID */
65void
66ssh_gssapi_set_oid(Gssctxt *ctx, gss_OID oid)
67{
68 ssh_gssapi_set_oid_data(ctx, oid->elements, oid->length);
69}
70
71/* All this effort to report an error ... */
72void
73ssh_gssapi_error(Gssctxt *ctxt)
74{
Damien Millera66cf682006-03-26 00:05:23 +110075 char *s;
76
77 s = ssh_gssapi_last_error(ctxt, NULL, NULL);
78 debug("%s", s);
79 xfree(s);
Darren Tucker0efd1552003-08-26 11:49:55 +100080}
81
82char *
Damien Miller0dc1bef2005-07-17 17:22:45 +100083ssh_gssapi_last_error(Gssctxt *ctxt, OM_uint32 *major_status,
84 OM_uint32 *minor_status)
Darren Tucker0efd1552003-08-26 11:49:55 +100085{
86 OM_uint32 lmin;
87 gss_buffer_desc msg = GSS_C_EMPTY_BUFFER;
88 OM_uint32 ctx;
89 Buffer b;
90 char *ret;
91
92 buffer_init(&b);
93
94 if (major_status != NULL)
95 *major_status = ctxt->major;
96 if (minor_status != NULL)
97 *minor_status = ctxt->minor;
98
99 ctx = 0;
100 /* The GSSAPI error */
101 do {
102 gss_display_status(&lmin, ctxt->major,
103 GSS_C_GSS_CODE, GSS_C_NULL_OID, &ctx, &msg);
104
105 buffer_append(&b, msg.value, msg.length);
106 buffer_put_char(&b, '\n');
107
108 gss_release_buffer(&lmin, &msg);
109 } while (ctx != 0);
110
111 /* The mechanism specific error */
112 do {
113 gss_display_status(&lmin, ctxt->minor,
114 GSS_C_MECH_CODE, GSS_C_NULL_OID, &ctx, &msg);
115
116 buffer_append(&b, msg.value, msg.length);
117 buffer_put_char(&b, '\n');
118
119 gss_release_buffer(&lmin, &msg);
120 } while (ctx != 0);
121
122 buffer_put_char(&b, '\0');
123 ret = xmalloc(buffer_len(&b));
124 buffer_get(&b, ret, buffer_len(&b));
125 buffer_free(&b);
126 return (ret);
127}
128
129/*
130 * Initialise our GSSAPI context. We use this opaque structure to contain all
131 * of the data which both the client and server need to persist across
132 * {accept,init}_sec_context calls, so that when we do it from the userauth
133 * stuff life is a little easier
134 */
135void
136ssh_gssapi_build_ctx(Gssctxt **ctx)
137{
138 *ctx = xmalloc(sizeof (Gssctxt));
139 (*ctx)->major = 0;
140 (*ctx)->minor = 0;
141 (*ctx)->context = GSS_C_NO_CONTEXT;
142 (*ctx)->name = GSS_C_NO_NAME;
143 (*ctx)->oid = GSS_C_NO_OID;
144 (*ctx)->creds = GSS_C_NO_CREDENTIAL;
145 (*ctx)->client = GSS_C_NO_NAME;
146 (*ctx)->client_creds = GSS_C_NO_CREDENTIAL;
147}
148
149/* Delete our context, providing it has been built correctly */
150void
151ssh_gssapi_delete_ctx(Gssctxt **ctx)
152{
153 OM_uint32 ms;
154
155 if ((*ctx) == NULL)
156 return;
157 if ((*ctx)->context != GSS_C_NO_CONTEXT)
158 gss_delete_sec_context(&ms, &(*ctx)->context, GSS_C_NO_BUFFER);
159 if ((*ctx)->name != GSS_C_NO_NAME)
160 gss_release_name(&ms, &(*ctx)->name);
161 if ((*ctx)->oid != GSS_C_NO_OID) {
162 xfree((*ctx)->oid->elements);
163 xfree((*ctx)->oid);
164 (*ctx)->oid = GSS_C_NO_OID;
165 }
166 if ((*ctx)->creds != GSS_C_NO_CREDENTIAL)
167 gss_release_cred(&ms, &(*ctx)->creds);
168 if ((*ctx)->client != GSS_C_NO_NAME)
169 gss_release_name(&ms, &(*ctx)->client);
170 if ((*ctx)->client_creds != GSS_C_NO_CREDENTIAL)
171 gss_release_cred(&ms, &(*ctx)->client_creds);
172
173 xfree(*ctx);
174 *ctx = NULL;
175}
176
177/*
178 * Wrapper to init_sec_context
179 * Requires that the context contains:
180 * oid
181 * server name (from ssh_gssapi_import_name)
182 */
183OM_uint32
184ssh_gssapi_init_ctx(Gssctxt *ctx, int deleg_creds, gss_buffer_desc *recv_tok,
185 gss_buffer_desc* send_tok, OM_uint32 *flags)
186{
187 int deleg_flag = 0;
188
189 if (deleg_creds) {
190 deleg_flag = GSS_C_DELEG_FLAG;
191 debug("Delegating credentials");
192 }
193
194 ctx->major = gss_init_sec_context(&ctx->minor,
195 GSS_C_NO_CREDENTIAL, &ctx->context, ctx->name, ctx->oid,
196 GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG | deleg_flag,
197 0, NULL, recv_tok, NULL, send_tok, flags, NULL);
198
199 if (GSS_ERROR(ctx->major))
200 ssh_gssapi_error(ctx);
201
202 return (ctx->major);
203}
204
205/* Create a service name for the given host */
206OM_uint32
207ssh_gssapi_import_name(Gssctxt *ctx, const char *host)
208{
209 gss_buffer_desc gssbuf;
210
211 gssbuf.length = sizeof("host@") + strlen(host);
212 gssbuf.value = xmalloc(gssbuf.length);
213 snprintf(gssbuf.value, gssbuf.length, "host@%s", host);
214
215 if ((ctx->major = gss_import_name(&ctx->minor,
216 &gssbuf, GSS_C_NT_HOSTBASED_SERVICE, &ctx->name)))
217 ssh_gssapi_error(ctx);
218
219 xfree(gssbuf.value);
220 return (ctx->major);
221}
222
223/* Acquire credentials for a server running on the current host.
224 * Requires that the context structure contains a valid OID
225 */
226
227/* Returns a GSSAPI error code */
228OM_uint32
229ssh_gssapi_acquire_cred(Gssctxt *ctx)
230{
231 OM_uint32 status;
232 char lname[MAXHOSTNAMELEN];
233 gss_OID_set oidset;
234
235 gss_create_empty_oid_set(&status, &oidset);
236 gss_add_oid_set_member(&status, ctx->oid, &oidset);
237
Damien Millera66cf682006-03-26 00:05:23 +1100238 if (gethostname(lname, MAXHOSTNAMELEN)) {
239 gss_release_oid_set(&status, &oidset);
Darren Tucker0efd1552003-08-26 11:49:55 +1000240 return (-1);
Damien Millera66cf682006-03-26 00:05:23 +1100241 }
Darren Tucker0efd1552003-08-26 11:49:55 +1000242
Damien Millera66cf682006-03-26 00:05:23 +1100243 if (GSS_ERROR(ssh_gssapi_import_name(ctx, lname))) {
244 gss_release_oid_set(&status, &oidset);
Darren Tucker0efd1552003-08-26 11:49:55 +1000245 return (ctx->major);
Damien Millera66cf682006-03-26 00:05:23 +1100246 }
Darren Tucker0efd1552003-08-26 11:49:55 +1000247
248 if ((ctx->major = gss_acquire_cred(&ctx->minor,
249 ctx->name, 0, oidset, GSS_C_ACCEPT, &ctx->creds, NULL, NULL)))
250 ssh_gssapi_error(ctx);
251
252 gss_release_oid_set(&status, &oidset);
253 return (ctx->major);
254}
255
256OM_uint32
Damien Miller0425d402003-11-17 22:18:21 +1100257ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
258{
259 if ((ctx->major = gss_get_mic(&ctx->minor, ctx->context,
260 GSS_C_QOP_DEFAULT, buffer, hash)))
261 ssh_gssapi_error(ctx);
Damien Miller787b2ec2003-11-21 23:56:47 +1100262
Damien Miller0425d402003-11-17 22:18:21 +1100263 return (ctx->major);
264}
265
266void
Damien Millera8e06ce2003-11-21 23:48:55 +1100267ssh_gssapi_buildmic(Buffer *b, const char *user, const char *service,
268 const char *context)
Damien Miller787b2ec2003-11-21 23:56:47 +1100269{
Damien Miller0425d402003-11-17 22:18:21 +1100270 buffer_init(b);
271 buffer_put_string(b, session_id2, session_id2_len);
272 buffer_put_char(b, SSH2_MSG_USERAUTH_REQUEST);
273 buffer_put_cstring(b, user);
274 buffer_put_cstring(b, service);
275 buffer_put_cstring(b, context);
276}
277
278OM_uint32
Damien Miller6fd6def2005-11-05 15:07:05 +1100279ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID oid)
280{
Darren Tucker0efd1552003-08-26 11:49:55 +1000281 if (*ctx)
282 ssh_gssapi_delete_ctx(ctx);
283 ssh_gssapi_build_ctx(ctx);
284 ssh_gssapi_set_oid(*ctx, oid);
285 return (ssh_gssapi_acquire_cred(*ctx));
286}
287
288#endif /* GSSAPI */