blob: 9bc31aa2a2a1ae61130f85e604c7dfbad9b7d69c [file] [log] [blame]
Damien Miller0dc1bef2005-07-17 17:22:45 +10001/* $OpenBSD: gss-genr.c,v 1.4 2005/07/17 07:17:55 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"
33#include "compat.h"
34#include "log.h"
35#include "monitor_wrap.h"
Damien Miller0425d402003-11-17 22:18:21 +110036#include "ssh2.h"
Darren Tucker0efd1552003-08-26 11:49:55 +100037
38#include "ssh-gss.h"
39
Damien Miller0425d402003-11-17 22:18:21 +110040extern u_char *session_id2;
41extern u_int session_id2_len;
Darren Tucker0efd1552003-08-26 11:49:55 +100042
43/* Check that the OID in a data stream matches that in the context */
44int
45ssh_gssapi_check_oid(Gssctxt *ctx, void *data, size_t len)
46{
47 return (ctx != NULL && ctx->oid != GSS_C_NO_OID &&
48 ctx->oid->length == len &&
49 memcmp(ctx->oid->elements, data, len) == 0);
50}
51
52/* Set the contexts OID from a data stream */
53void
54ssh_gssapi_set_oid_data(Gssctxt *ctx, void *data, size_t len)
55{
56 if (ctx->oid != GSS_C_NO_OID) {
57 xfree(ctx->oid->elements);
58 xfree(ctx->oid);
59 }
60 ctx->oid = xmalloc(sizeof(gss_OID_desc));
61 ctx->oid->length = len;
62 ctx->oid->elements = xmalloc(len);
63 memcpy(ctx->oid->elements, data, len);
64}
65
66/* Set the contexts OID */
67void
68ssh_gssapi_set_oid(Gssctxt *ctx, gss_OID oid)
69{
70 ssh_gssapi_set_oid_data(ctx, oid->elements, oid->length);
71}
72
73/* All this effort to report an error ... */
74void
75ssh_gssapi_error(Gssctxt *ctxt)
76{
77 debug("%s", ssh_gssapi_last_error(ctxt, NULL, NULL));
78}
79
80char *
Damien Miller0dc1bef2005-07-17 17:22:45 +100081ssh_gssapi_last_error(Gssctxt *ctxt, OM_uint32 *major_status,
82 OM_uint32 *minor_status)
Darren Tucker0efd1552003-08-26 11:49:55 +100083{
84 OM_uint32 lmin;
85 gss_buffer_desc msg = GSS_C_EMPTY_BUFFER;
86 OM_uint32 ctx;
87 Buffer b;
88 char *ret;
89
90 buffer_init(&b);
91
92 if (major_status != NULL)
93 *major_status = ctxt->major;
94 if (minor_status != NULL)
95 *minor_status = ctxt->minor;
96
97 ctx = 0;
98 /* The GSSAPI error */
99 do {
100 gss_display_status(&lmin, ctxt->major,
101 GSS_C_GSS_CODE, GSS_C_NULL_OID, &ctx, &msg);
102
103 buffer_append(&b, msg.value, msg.length);
104 buffer_put_char(&b, '\n');
105
106 gss_release_buffer(&lmin, &msg);
107 } while (ctx != 0);
108
109 /* The mechanism specific error */
110 do {
111 gss_display_status(&lmin, ctxt->minor,
112 GSS_C_MECH_CODE, GSS_C_NULL_OID, &ctx, &msg);
113
114 buffer_append(&b, msg.value, msg.length);
115 buffer_put_char(&b, '\n');
116
117 gss_release_buffer(&lmin, &msg);
118 } while (ctx != 0);
119
120 buffer_put_char(&b, '\0');
121 ret = xmalloc(buffer_len(&b));
122 buffer_get(&b, ret, buffer_len(&b));
123 buffer_free(&b);
124 return (ret);
125}
126
127/*
128 * Initialise our GSSAPI context. We use this opaque structure to contain all
129 * of the data which both the client and server need to persist across
130 * {accept,init}_sec_context calls, so that when we do it from the userauth
131 * stuff life is a little easier
132 */
133void
134ssh_gssapi_build_ctx(Gssctxt **ctx)
135{
136 *ctx = xmalloc(sizeof (Gssctxt));
137 (*ctx)->major = 0;
138 (*ctx)->minor = 0;
139 (*ctx)->context = GSS_C_NO_CONTEXT;
140 (*ctx)->name = GSS_C_NO_NAME;
141 (*ctx)->oid = GSS_C_NO_OID;
142 (*ctx)->creds = GSS_C_NO_CREDENTIAL;
143 (*ctx)->client = GSS_C_NO_NAME;
144 (*ctx)->client_creds = GSS_C_NO_CREDENTIAL;
145}
146
147/* Delete our context, providing it has been built correctly */
148void
149ssh_gssapi_delete_ctx(Gssctxt **ctx)
150{
151 OM_uint32 ms;
152
153 if ((*ctx) == NULL)
154 return;
155 if ((*ctx)->context != GSS_C_NO_CONTEXT)
156 gss_delete_sec_context(&ms, &(*ctx)->context, GSS_C_NO_BUFFER);
157 if ((*ctx)->name != GSS_C_NO_NAME)
158 gss_release_name(&ms, &(*ctx)->name);
159 if ((*ctx)->oid != GSS_C_NO_OID) {
160 xfree((*ctx)->oid->elements);
161 xfree((*ctx)->oid);
162 (*ctx)->oid = GSS_C_NO_OID;
163 }
164 if ((*ctx)->creds != GSS_C_NO_CREDENTIAL)
165 gss_release_cred(&ms, &(*ctx)->creds);
166 if ((*ctx)->client != GSS_C_NO_NAME)
167 gss_release_name(&ms, &(*ctx)->client);
168 if ((*ctx)->client_creds != GSS_C_NO_CREDENTIAL)
169 gss_release_cred(&ms, &(*ctx)->client_creds);
170
171 xfree(*ctx);
172 *ctx = NULL;
173}
174
175/*
176 * Wrapper to init_sec_context
177 * Requires that the context contains:
178 * oid
179 * server name (from ssh_gssapi_import_name)
180 */
181OM_uint32
182ssh_gssapi_init_ctx(Gssctxt *ctx, int deleg_creds, gss_buffer_desc *recv_tok,
183 gss_buffer_desc* send_tok, OM_uint32 *flags)
184{
185 int deleg_flag = 0;
186
187 if (deleg_creds) {
188 deleg_flag = GSS_C_DELEG_FLAG;
189 debug("Delegating credentials");
190 }
191
192 ctx->major = gss_init_sec_context(&ctx->minor,
193 GSS_C_NO_CREDENTIAL, &ctx->context, ctx->name, ctx->oid,
194 GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG | deleg_flag,
195 0, NULL, recv_tok, NULL, send_tok, flags, NULL);
196
197 if (GSS_ERROR(ctx->major))
198 ssh_gssapi_error(ctx);
199
200 return (ctx->major);
201}
202
203/* Create a service name for the given host */
204OM_uint32
205ssh_gssapi_import_name(Gssctxt *ctx, const char *host)
206{
207 gss_buffer_desc gssbuf;
208
209 gssbuf.length = sizeof("host@") + strlen(host);
210 gssbuf.value = xmalloc(gssbuf.length);
211 snprintf(gssbuf.value, gssbuf.length, "host@%s", host);
212
213 if ((ctx->major = gss_import_name(&ctx->minor,
214 &gssbuf, GSS_C_NT_HOSTBASED_SERVICE, &ctx->name)))
215 ssh_gssapi_error(ctx);
216
217 xfree(gssbuf.value);
218 return (ctx->major);
219}
220
221/* Acquire credentials for a server running on the current host.
222 * Requires that the context structure contains a valid OID
223 */
224
225/* Returns a GSSAPI error code */
226OM_uint32
227ssh_gssapi_acquire_cred(Gssctxt *ctx)
228{
229 OM_uint32 status;
230 char lname[MAXHOSTNAMELEN];
231 gss_OID_set oidset;
232
233 gss_create_empty_oid_set(&status, &oidset);
234 gss_add_oid_set_member(&status, ctx->oid, &oidset);
235
236 if (gethostname(lname, MAXHOSTNAMELEN))
237 return (-1);
238
239 if (GSS_ERROR(ssh_gssapi_import_name(ctx, lname)))
240 return (ctx->major);
241
242 if ((ctx->major = gss_acquire_cred(&ctx->minor,
243 ctx->name, 0, oidset, GSS_C_ACCEPT, &ctx->creds, NULL, NULL)))
244 ssh_gssapi_error(ctx);
245
246 gss_release_oid_set(&status, &oidset);
247 return (ctx->major);
248}
249
250OM_uint32
Damien Miller0425d402003-11-17 22:18:21 +1100251ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
252{
253 if ((ctx->major = gss_get_mic(&ctx->minor, ctx->context,
254 GSS_C_QOP_DEFAULT, buffer, hash)))
255 ssh_gssapi_error(ctx);
Damien Miller787b2ec2003-11-21 23:56:47 +1100256
Damien Miller0425d402003-11-17 22:18:21 +1100257 return (ctx->major);
258}
259
260void
Damien Millera8e06ce2003-11-21 23:48:55 +1100261ssh_gssapi_buildmic(Buffer *b, const char *user, const char *service,
262 const char *context)
Damien Miller787b2ec2003-11-21 23:56:47 +1100263{
Damien Miller0425d402003-11-17 22:18:21 +1100264 buffer_init(b);
265 buffer_put_string(b, session_id2, session_id2_len);
266 buffer_put_char(b, SSH2_MSG_USERAUTH_REQUEST);
267 buffer_put_cstring(b, user);
268 buffer_put_cstring(b, service);
269 buffer_put_cstring(b, context);
270}
271
272OM_uint32
Darren Tucker0efd1552003-08-26 11:49:55 +1000273ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID oid) {
274 if (*ctx)
275 ssh_gssapi_delete_ctx(ctx);
276 ssh_gssapi_build_ctx(ctx);
277 ssh_gssapi_set_oid(*ctx, oid);
278 return (ssh_gssapi_acquire_cred(*ctx));
279}
280
281#endif /* GSSAPI */