2 Unix SMB/CIFS implementation.
3 kerberos authorization data (PAC) utility library
4 Copyright (C) Andrew Bartlett <abartlet@samba.org> 2011
5 Copyright (C) Simo Sorce 2010.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>.
24 #define DBGC_CLASS DBGC_AUTH
28 #include "auth/kerberos/pac_utils.h"
31 /* FIXME - need proper configure/waf test
32 * to determine if gss_mech_krb5 and friends
36 * These are not exported by Solaris -lkrb5
37 * Maybe move to libreplace somewhere?
39 static const gss_OID_desc krb5_gss_oid_array[] = {
40 /* this is the official, rfc-specified OID */
41 { 9, "\052\206\110\206\367\022\001\002\002" },
42 /* this is the pre-RFC mech OID */
43 { 5, "\053\005\001\005\002" },
44 /* this is the unofficial, incorrect mech OID emitted by MS */
45 { 9, "\052\206\110\202\367\022\001\002\002" },
49 const gss_OID_desc * const gss_mech_krb5 = krb5_gss_oid_array+0;
50 const gss_OID_desc * const gss_mech_krb5_old = krb5_gss_oid_array+1;
51 const gss_OID_desc * const gss_mech_krb5_wrong = krb5_gss_oid_array+2;
54 #ifndef GSS_KRB5_INQ_SSPI_SESSION_KEY_OID
55 #define GSS_KRB5_INQ_SSPI_SESSION_KEY_OID_LENGTH 11
56 #define GSS_KRB5_INQ_SSPI_SESSION_KEY_OID "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02\x05\x05"
59 gss_OID_desc gse_sesskey_inq_oid = {
60 GSS_KRB5_INQ_SSPI_SESSION_KEY_OID_LENGTH,
61 discard_const(GSS_KRB5_INQ_SSPI_SESSION_KEY_OID)
64 #ifndef GSS_KRB5_SESSION_KEY_ENCTYPE_OID
65 #define GSS_KRB5_SESSION_KEY_ENCTYPE_OID_LENGTH 10
66 #define GSS_KRB5_SESSION_KEY_ENCTYPE_OID "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02\x04"
69 gss_OID_desc gse_sesskeytype_oid = {
70 GSS_KRB5_SESSION_KEY_ENCTYPE_OID_LENGTH,
71 discard_const(GSS_KRB5_SESSION_KEY_ENCTYPE_OID)
74 /* The Heimdal OID for getting the PAC */
75 #define EXTRACT_PAC_AUTHZ_DATA_FROM_SEC_CONTEXT_OID_LENGTH 8
76 /* EXTRACTION OID AUTHZ ID */
77 #define EXTRACT_PAC_AUTHZ_DATA_FROM_SEC_CONTEXT_OID "\x2a\x85\x70\x2b\x0d\x03" "\x81\x00"
79 NTSTATUS gssapi_obtain_pac_blob(TALLOC_CTX *mem_ctx,
80 gss_ctx_id_t gssapi_context,
81 gss_name_t gss_client_name,
85 OM_uint32 gss_maj, gss_min;
86 #ifdef HAVE_GSS_GET_NAME_ATTRIBUTE
88 * gss_get_name_attribute() in MIT krb5 1.10.0 can return unintialized pac_display_buffer
89 * and later gss_release_buffer() will crash on attempting to release it.
91 * So always initialize the buffer descriptors.
93 * See following links for more details:
94 * http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=658514
95 * http://krbdev.mit.edu/rt/Ticket/Display.html?user=guest&pass=guest&id=7087
97 gss_buffer_desc pac_buffer = {
101 gss_buffer_desc pac_display_buffer = {
105 gss_buffer_desc pac_name = {
106 .value = discard_const("urn:mspac:"),
107 .length = sizeof("urn:mspac:")-1
110 int authenticated = false;
111 int complete = false;
113 gss_maj = gss_get_name_attribute(
114 &gss_min, gss_client_name, &pac_name,
115 &authenticated, &complete,
116 &pac_buffer, &pac_display_buffer, &more);
119 gss_OID oid = discard_const(gss_mech_krb5);
120 DBG_NOTICE("obtaining PAC via GSSAPI gss_get_name_attribute "
121 "failed: %s\n", gssapi_error_string(mem_ctx,
124 return NT_STATUS_ACCESS_DENIED;
125 } else if (authenticated && complete) {
126 /* The PAC blob is returned directly */
127 *pac_blob = data_blob_talloc(mem_ctx, pac_buffer.value,
130 if (!pac_blob->data) {
131 status = NT_STATUS_NO_MEMORY;
133 status = NT_STATUS_OK;
136 gss_maj = gss_release_buffer(&gss_min, &pac_buffer);
137 gss_maj = gss_release_buffer(&gss_min, &pac_display_buffer);
140 DEBUG(0, ("obtaining PAC via GSSAPI failed: authenticated: %s, complete: %s, more: %s\n",
141 authenticated ? "true" : "false",
142 complete ? "true" : "false",
143 more ? "true" : "false"));
144 return NT_STATUS_ACCESS_DENIED;
147 #elif defined(HAVE_GSS_INQUIRE_SEC_CONTEXT_BY_OID)
148 gss_OID_desc pac_data_oid = {
149 .elements = discard_const(EXTRACT_PAC_AUTHZ_DATA_FROM_SEC_CONTEXT_OID),
150 .length = EXTRACT_PAC_AUTHZ_DATA_FROM_SEC_CONTEXT_OID_LENGTH
153 gss_buffer_set_t set = GSS_C_NO_BUFFER_SET;
155 /* If we didn't have the routine to get a verified, validated
156 * PAC (supplied only by MIT at the time of writing), then try
157 * with the Heimdal OID (fetches the PAC directly and always
159 gss_maj = gss_inquire_sec_context_by_oid(
160 &gss_min, gssapi_context,
161 &pac_data_oid, &set);
163 /* First check for the error MIT gives for an unknown OID */
164 if (gss_maj == GSS_S_UNAVAILABLE) {
165 DEBUG(1, ("unable to obtain a PAC against this GSSAPI library. "
166 "GSSAPI secured connections are available only with Heimdal or MIT Kerberos >= 1.8\n"));
167 } else if (gss_maj != 0) {
168 DEBUG(2, ("obtaining PAC via GSSAPI gss_inquire_sec_context_by_oid (Heimdal OID) failed: %s\n",
169 gssapi_error_string(mem_ctx, gss_maj, gss_min, gss_mech_krb5)));
171 if (set == GSS_C_NO_BUFFER_SET) {
172 DEBUG(0, ("gss_inquire_sec_context_by_oid returned unknown "
173 "data in results.\n"));
174 return NT_STATUS_INTERNAL_ERROR;
177 /* The PAC blob is returned directly */
178 *pac_blob = data_blob_talloc(mem_ctx, set->elements[0].value,
179 set->elements[0].length);
180 if (!pac_blob->data) {
181 status = NT_STATUS_NO_MEMORY;
183 status = NT_STATUS_OK;
186 gss_maj = gss_release_buffer_set(&gss_min, &set);
190 DEBUG(1, ("unable to obtain a PAC against this GSSAPI library. "
191 "GSSAPI secured connections are available only with Heimdal or MIT Kerberos >= 1.8\n"));
193 return NT_STATUS_ACCESS_DENIED;
196 NTSTATUS gssapi_get_session_key(TALLOC_CTX *mem_ctx,
197 gss_ctx_id_t gssapi_context,
198 DATA_BLOB *session_key,
201 OM_uint32 gss_min, gss_maj;
202 gss_buffer_set_t set = GSS_C_NO_BUFFER_SET;
204 gss_maj = gss_inquire_sec_context_by_oid(
205 &gss_min, gssapi_context,
206 &gse_sesskey_inq_oid, &set);
208 DEBUG(0, ("gss_inquire_sec_context_by_oid failed [%s]\n",
209 gssapi_error_string(mem_ctx,
212 discard_const_p(struct gss_OID_desc_struct,
214 return NT_STATUS_NO_USER_SESSION_KEY;
217 if ((set == GSS_C_NO_BUFFER_SET) ||
219 #ifdef HAVE_GSSKRB5_GET_SUBKEY
220 krb5_keyblock *subkey;
221 gss_maj = gsskrb5_get_subkey(&gss_min,
225 DEBUG(1, ("NO session key for this mech\n"));
226 return NT_STATUS_NO_USER_SESSION_KEY;
229 *session_key = data_blob_talloc(mem_ctx,
230 KRB5_KEY_DATA(subkey), KRB5_KEY_LENGTH(subkey));
233 *keytype = KRB5_KEY_TYPE(subkey);
235 krb5_free_keyblock(NULL /* should be krb5_context */, subkey);
238 DEBUG(0, ("gss_inquire_sec_context_by_oid didn't return any session key (and no alternative method available)\n"));
239 return NT_STATUS_NO_USER_SESSION_KEY;
244 *session_key = data_blob_talloc(mem_ctx, set->elements[0].value,
245 set->elements[0].length);
253 if (set->count < 2) {
255 #ifdef HAVE_GSSKRB5_GET_SUBKEY
256 krb5_keyblock *subkey;
257 gss_maj = gsskrb5_get_subkey(&gss_min,
261 *keytype = KRB5_KEY_TYPE(subkey);
262 krb5_free_keyblock(NULL /* should be krb5_context */, subkey);
265 gss_maj = gss_release_buffer_set(&gss_min, &set);
269 } else if (memcmp(set->elements[1].value,
270 gse_sesskeytype_oid.elements,
271 gse_sesskeytype_oid.length) != 0) {
272 /* Perhaps a non-krb5 session key */
273 gss_maj = gss_release_buffer_set(&gss_min, &set);
276 p = (const uint8_t *)set->elements[1].value + gse_sesskeytype_oid.length;
277 diflen = set->elements[1].length - gse_sesskeytype_oid.length;
279 gss_maj = gss_release_buffer_set(&gss_min, &set);
280 return NT_STATUS_INVALID_PARAMETER;
282 for (i = 0; i < diflen; i++) {
283 *keytype = (*keytype << 7) | (p[i] & 0x7f);
284 if (i + 1 != diflen && (p[i] & 0x80) == 0) {
285 gss_maj = gss_release_buffer_set(&gss_min, &set);
286 return NT_STATUS_INVALID_PARAMETER;
291 gss_maj = gss_release_buffer_set(&gss_min, &set);
296 char *gssapi_error_string(TALLOC_CTX *mem_ctx,
297 OM_uint32 maj_stat, OM_uint32 min_stat,
300 OM_uint32 disp_min_stat, disp_maj_stat;
301 gss_buffer_desc maj_error_message;
302 gss_buffer_desc min_error_message;
303 char *maj_error_string, *min_error_string;
304 OM_uint32 msg_ctx = 0;
308 maj_error_message.value = NULL;
309 min_error_message.value = NULL;
310 maj_error_message.length = 0;
311 min_error_message.length = 0;
313 disp_maj_stat = gss_display_status(&disp_min_stat, maj_stat,
314 GSS_C_GSS_CODE, mech,
315 &msg_ctx, &maj_error_message);
316 if (disp_maj_stat != 0) {
317 maj_error_message.value = NULL;
318 maj_error_message.length = 0;
320 disp_maj_stat = gss_display_status(&disp_min_stat, min_stat,
321 GSS_C_MECH_CODE, mech,
322 &msg_ctx, &min_error_message);
323 if (disp_maj_stat != 0) {
324 min_error_message.value = NULL;
325 min_error_message.length = 0;
328 maj_error_string = talloc_strndup(mem_ctx,
329 (char *)maj_error_message.value,
330 maj_error_message.length);
332 min_error_string = talloc_strndup(mem_ctx,
333 (char *)min_error_message.value,
334 min_error_message.length);
336 ret = talloc_asprintf(mem_ctx, "%s: %s",
337 maj_error_string, min_error_string);
339 talloc_free(maj_error_string);
340 talloc_free(min_error_string);
342 gss_release_buffer(&disp_min_stat, &maj_error_message);
343 gss_release_buffer(&disp_min_stat, &min_error_message);
348 #endif /* HAVE_KRB5 */