1 /* $OpenBSD: gss-serv.c,v 1.22 2008/05/08 12:02:23 djm Exp $ */
4 * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
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.
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.
31 #include <sys/types.h>
32 #include <sys/param.h>
38 #include "openbsd-compat/sys-queue.h"
51 static ssh_gssapi_client gssapi_client =
52 { GSS_C_EMPTY_BUFFER, GSS_C_EMPTY_BUFFER,
53 GSS_C_NO_CREDENTIAL, GSS_C_NO_NAME, {NULL, NULL, NULL}};
56 * Acquire credentials for a server running on the current host.
57 * Requires that the context structure contains a valid OID
60 /* Returns a GSSAPI error code */
61 /* Privileged (called from ssh_gssapi_server_ctx) */
63 ssh_gssapi_acquire_cred(Gssctxt *ctx)
66 char lname[MAXHOSTNAMELEN];
69 gss_create_empty_oid_set(&status, &oidset);
70 gss_add_oid_set_member(&status, ctx->oid, &oidset);
72 if (gethostname(lname, MAXHOSTNAMELEN)) {
73 gss_release_oid_set(&status, &oidset);
77 if (GSS_ERROR(ssh_gssapi_import_name(ctx, lname))) {
78 gss_release_oid_set(&status, &oidset);
82 if ((ctx->major = gss_acquire_cred(&ctx->minor,
83 ctx->name, 0, oidset, GSS_C_ACCEPT, &ctx->creds, NULL, NULL)))
84 ssh_gssapi_error(ctx);
86 gss_release_oid_set(&status, &oidset);
92 ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID oid)
95 ssh_gssapi_delete_ctx(ctx);
96 ssh_gssapi_build_ctx(ctx);
97 ssh_gssapi_set_oid(*ctx, oid);
98 return (ssh_gssapi_acquire_cred(*ctx));
103 ssh_gssapi_supported_oids(gss_OID_set *oidset)
105 OM_uint32 min_status;
107 gss_indicate_mechs(&min_status, oidset);
111 /* Wrapper around accept_sec_context
112 * Requires that the context contains:
114 * credentials (from ssh_gssapi_acquire_cred)
118 ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *recv_tok,
119 gss_buffer_desc *send_tok, OM_uint32 *flags)
124 ctx->major = gss_accept_sec_context(&ctx->minor,
125 &ctx->context, ctx->creds, recv_tok,
126 GSS_C_NO_CHANNEL_BINDINGS, &ctx->client, &mech,
127 send_tok, flags, NULL, &ctx->client_creds);
129 if (GSS_ERROR(ctx->major))
130 ssh_gssapi_error(ctx);
132 if (ctx->client_creds)
133 debug("Received some client credentials");
135 debug("Got no client credentials");
139 /* Now, if we're complete and we have the right flags, then
140 * we flag the user as also having been authenticated
143 if (((flags == NULL) || ((*flags & GSS_C_MUTUAL_FLAG) &&
144 (*flags & GSS_C_INTEG_FLAG))) && (ctx->major == GSS_S_COMPLETE)) {
145 if (ssh_gssapi_getclient(ctx, &gssapi_client))
146 fatal("Couldn't convert client name");
153 * This parses an exported name, extracting the mechanism specific portion
154 * to use for ACL checking. It verifies that the name belongs the mechanism
155 * originally selected.
158 ssh_gssapi_parse_ename(Gssctxt *ctx, gss_buffer_t ename, gss_buffer_t name)
167 * Check that ename is long enough for all of the fixed length
168 * header, and that the initial ID bytes are correct
171 if (ename->length < 6 || memcmp(tok, "\x04\x01", 2) != 0)
172 return GSS_S_FAILURE;
175 * Extract the OID, and check it. Here GSSAPI breaks with tradition
176 * and does use the OID type and length bytes. To confuse things
177 * there are two lengths - the first including these, and the
181 oidl = get_u16(tok+2); /* length including next two bytes */
182 oidl = oidl-2; /* turn it into the _real_ length of the variable OID */
185 * Check the BER encoding for correct type and length, that the
186 * string is long enough and that the OID matches that in our context
188 if (tok[4] != 0x06 || tok[5] != oidl ||
189 ename->length < oidl+6 ||
190 !ssh_gssapi_check_oid(ctx, tok+6, oidl))
191 return GSS_S_FAILURE;
195 if (ename->length < offset+4)
196 return GSS_S_FAILURE;
198 name->length = get_u32(tok+offset);
201 if (ename->length < offset+name->length)
202 return GSS_S_FAILURE;
204 name->value = xmalloc(name->length+1);
205 memcpy(name->value, tok+offset, name->length);
206 ((char *)name->value)[name->length] = 0;
208 return GSS_S_COMPLETE;
211 /* Extract the client details from a given context. This can only reliably
212 * be called once for a context */
214 /* Privileged (called from accept_secure_ctx) */
216 ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client)
218 gss_buffer_desc ename;
220 if ((ctx->major = gss_display_name(&ctx->minor, ctx->client,
221 &client->displayname, NULL))) {
222 ssh_gssapi_error(ctx);
226 if ((ctx->major = gss_duplicate_name(&ctx->minor, ctx->client,
228 ssh_gssapi_error(ctx);
232 if ((ctx->major = gss_export_name(&ctx->minor, ctx->client,
234 ssh_gssapi_error(ctx);
238 if ((ctx->major = ssh_gssapi_parse_ename(ctx,&ename,
239 &client->exportedname))) {
243 /* We can't copy this structure, so we just move the pointer to it */
244 client->creds = ctx->client_creds;
245 ctx->client_creds = GSS_C_NO_CREDENTIAL;
249 /* As user - called on fatal/exit */
251 ssh_gssapi_cleanup_creds(void)
253 if (gssapi_client.store.filename != NULL) {
254 /* Unlink probably isn't sufficient */
255 debug("removing gssapi cred file\"%s\"",
256 gssapi_client.store.filename);
257 unlink(gssapi_client.store.filename);
263 ssh_gssapi_storecreds(void)
267 gss_store_cred(&lmin, gssapi_client.creds,
268 GSS_C_INITIATE, GSS_C_NO_OID,
272 /* This allows GSSAPI methods to do things to the childs environment based
273 * on the passed authentication process and credentials.
277 ssh_gssapi_do_child(char ***envp, u_int *envsizep)
280 if (gssapi_client.store.envvar != NULL &&
281 gssapi_client.store.envval != NULL) {
282 debug("Setting %s to %s", gssapi_client.store.envvar,
283 gssapi_client.store.envval);
284 child_set_env(envp, envsizep, gssapi_client.store.envvar,
285 gssapi_client.store.envval);
291 ssh_gssapi_userok(char *user)
296 if (gssapi_client.exportedname.length == 0 ||
297 gssapi_client.exportedname.value == NULL) {
298 debug("No suitable client data");
301 if (GSS_ERROR(gss_userok(&lmin, gssapi_client.name, user, &userok)) ||
303 /* Destroy delegated credentials if userok fails */
304 gss_release_buffer(&lmin, &gssapi_client.displayname);
305 gss_release_buffer(&lmin, &gssapi_client.exportedname);
306 gss_release_name(&lmin, &gssapi_client.name);
307 gss_release_cred(&lmin, &gssapi_client.creds);
308 memset(&gssapi_client, 0, sizeof(ssh_gssapi_client));
317 ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
319 ctx->major = gss_verify_mic(&ctx->minor, ctx->context,
320 gssbuf, gssmic, NULL);