1 /* $OpenBSD: gss-genr.c,v 1.24 2016/09/12 01:22:38 deraadt Exp $ */
4 * Copyright (c) 2001-2007 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>
46 extern u_char *session_id2;
47 extern u_int session_id2_len;
49 /* Check that the OID in a data stream matches that in the context */
51 ssh_gssapi_check_oid(Gssctxt *ctx, void *data, size_t len)
53 return (ctx != NULL && ctx->oid != GSS_C_NO_OID &&
54 ctx->oid->length == len &&
55 memcmp(ctx->oid->elements, data, len) == 0);
58 /* Set the contexts OID from a data stream */
60 ssh_gssapi_set_oid_data(Gssctxt *ctx, void *data, size_t len)
62 if (ctx->oid != GSS_C_NO_OID) {
63 free(ctx->oid->elements);
66 ctx->oid = xcalloc(1, sizeof(gss_OID_desc));
67 ctx->oid->length = len;
68 ctx->oid->elements = xmalloc(len);
69 memcpy(ctx->oid->elements, data, len);
72 /* Set the contexts OID */
74 ssh_gssapi_set_oid(Gssctxt *ctx, gss_OID oid)
76 ssh_gssapi_set_oid_data(ctx, oid->elements, oid->length);
79 /* All this effort to report an error ... */
81 ssh_gssapi_error(Gssctxt *ctxt)
85 s = ssh_gssapi_last_error(ctxt, NULL, NULL);
91 ssh_gssapi_last_error(Gssctxt *ctxt, OM_uint32 *major_status,
92 OM_uint32 *minor_status)
95 gss_buffer_desc msg = GSS_C_EMPTY_BUFFER;
102 if (major_status != NULL)
103 *major_status = ctxt->major;
104 if (minor_status != NULL)
105 *minor_status = ctxt->minor;
108 /* The GSSAPI error */
110 gss_display_status(&lmin, ctxt->major,
111 GSS_C_GSS_CODE, ctxt->oid, &ctx, &msg);
113 buffer_append(&b, msg.value, msg.length);
114 buffer_put_char(&b, '\n');
116 gss_release_buffer(&lmin, &msg);
119 /* The mechanism specific error */
121 gss_display_status(&lmin, ctxt->minor,
122 GSS_C_MECH_CODE, ctxt->oid, &ctx, &msg);
124 buffer_append(&b, msg.value, msg.length);
125 buffer_put_char(&b, '\n');
127 gss_release_buffer(&lmin, &msg);
130 buffer_put_char(&b, '\0');
131 ret = xmalloc(buffer_len(&b));
132 buffer_get(&b, ret, buffer_len(&b));
138 * Initialise our GSSAPI context. We use this opaque structure to contain all
139 * of the data which both the client and server need to persist across
140 * {accept,init}_sec_context calls, so that when we do it from the userauth
141 * stuff life is a little easier
144 ssh_gssapi_build_ctx(Gssctxt **ctx)
146 *ctx = xcalloc(1, sizeof (Gssctxt));
147 (*ctx)->context = GSS_C_NO_CONTEXT;
148 (*ctx)->name = GSS_C_NO_NAME;
149 (*ctx)->oid = GSS_C_NO_OID;
150 (*ctx)->creds = GSS_C_NO_CREDENTIAL;
151 (*ctx)->client = GSS_C_NO_NAME;
152 (*ctx)->client_creds = GSS_C_NO_CREDENTIAL;
155 /* Delete our context, providing it has been built correctly */
157 ssh_gssapi_delete_ctx(Gssctxt **ctx)
163 if ((*ctx)->context != GSS_C_NO_CONTEXT)
164 gss_delete_sec_context(&ms, &(*ctx)->context, GSS_C_NO_BUFFER);
165 if ((*ctx)->name != GSS_C_NO_NAME)
166 gss_release_name(&ms, &(*ctx)->name);
167 if ((*ctx)->oid != GSS_C_NO_OID) {
168 free((*ctx)->oid->elements);
170 (*ctx)->oid = GSS_C_NO_OID;
172 if ((*ctx)->creds != GSS_C_NO_CREDENTIAL)
173 gss_release_cred(&ms, &(*ctx)->creds);
174 if ((*ctx)->client != GSS_C_NO_NAME)
175 gss_release_name(&ms, &(*ctx)->client);
176 if ((*ctx)->client_creds != GSS_C_NO_CREDENTIAL)
177 gss_release_cred(&ms, &(*ctx)->client_creds);
184 * Wrapper to init_sec_context
185 * Requires that the context contains:
187 * server name (from ssh_gssapi_import_name)
190 ssh_gssapi_init_ctx(Gssctxt *ctx, int deleg_creds, gss_buffer_desc *recv_tok,
191 gss_buffer_desc* send_tok, OM_uint32 *flags)
196 deleg_flag = GSS_C_DELEG_FLAG;
197 debug("Delegating credentials");
200 ctx->major = gss_init_sec_context(&ctx->minor,
201 GSS_C_NO_CREDENTIAL, &ctx->context, ctx->name, ctx->oid,
202 GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG | deleg_flag,
203 0, NULL, recv_tok, NULL, send_tok, flags, NULL);
205 if (GSS_ERROR(ctx->major))
206 ssh_gssapi_error(ctx);
211 /* Create a service name for the given host */
213 ssh_gssapi_import_name(Gssctxt *ctx, const char *host)
215 gss_buffer_desc gssbuf;
218 xasprintf(&val, "host@%s", host);
220 gssbuf.length = strlen(gssbuf.value);
222 if ((ctx->major = gss_import_name(&ctx->minor,
223 &gssbuf, GSS_C_NT_HOSTBASED_SERVICE, &ctx->name)))
224 ssh_gssapi_error(ctx);
231 ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
233 if ((ctx->major = gss_get_mic(&ctx->minor, ctx->context,
234 GSS_C_QOP_DEFAULT, buffer, hash)))
235 ssh_gssapi_error(ctx);
241 ssh_gssapi_buildmic(Buffer *b, const char *user, const char *service,
245 buffer_put_string(b, session_id2, session_id2_len);
246 buffer_put_char(b, SSH2_MSG_USERAUTH_REQUEST);
247 buffer_put_cstring(b, user);
248 buffer_put_cstring(b, service);
249 buffer_put_cstring(b, context);
253 ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host)
255 gss_buffer_desc token = GSS_C_EMPTY_BUFFER;
256 OM_uint32 major, minor;
257 gss_OID_desc spnego_oid = {6, (void *)"\x2B\x06\x01\x05\x05\x02"};
259 /* RFC 4462 says we MUST NOT do SPNEGO */
260 if (oid->length == spnego_oid.length &&
261 (memcmp(oid->elements, spnego_oid.elements, oid->length) == 0))
262 return 0; /* false */
264 ssh_gssapi_build_ctx(ctx);
265 ssh_gssapi_set_oid(*ctx, oid);
266 major = ssh_gssapi_import_name(*ctx, host);
267 if (!GSS_ERROR(major)) {
268 major = ssh_gssapi_init_ctx(*ctx, 0, GSS_C_NO_BUFFER, &token,
270 gss_release_buffer(&minor, &token);
271 if ((*ctx)->context != GSS_C_NO_CONTEXT)
272 gss_delete_sec_context(&minor, &(*ctx)->context,
276 if (GSS_ERROR(major))
277 ssh_gssapi_delete_ctx(ctx);
279 return (!GSS_ERROR(major));