2 Unix SMB/CIFS implementation.
3 simple kerberos5/SPNEGO routines
4 Copyright (C) Andrew Tridgell 2001
5 Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2002
6 Copyright (C) Luke Howard 2003
7 Copyright (C) Jeremy Allison 2010
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>.
24 #include "../libcli/auth/spnego.h"
26 #include "../lib/util/asn1.h"
29 generate a negTokenInit packet given a list of supported
30 OIDs (the mechanisms) a blob, and a principal name string
33 DATA_BLOB spnego_gen_negTokenInit(TALLOC_CTX *ctx,
36 const char *principal)
40 DATA_BLOB ret = data_blob_null;
42 data = asn1_init(talloc_tos());
44 return data_blob_null;
47 if (!asn1_push_tag(data,ASN1_APPLICATION(0))) goto err;
48 if (!asn1_write_OID(data,OID_SPNEGO)) goto err;
49 if (!asn1_push_tag(data,ASN1_CONTEXT(0))) goto err;
50 if (!asn1_push_tag(data,ASN1_SEQUENCE(0))) goto err;
52 if (!asn1_push_tag(data,ASN1_CONTEXT(0))) goto err;
53 if (!asn1_push_tag(data,ASN1_SEQUENCE(0))) goto err;
54 for (i=0; OIDs[i]; i++) {
55 if (!asn1_write_OID(data,OIDs[i])) goto err;
57 if (!asn1_pop_tag(data)) goto err;
58 if (!asn1_pop_tag(data)) goto err;
60 if (psecblob && psecblob->length && psecblob->data) {
61 if (!asn1_push_tag(data, ASN1_CONTEXT(2))) goto err;
62 if (!asn1_write_OctetString(data,psecblob->data,
63 psecblob->length)) goto err;
64 if (!asn1_pop_tag(data)) goto err;
68 if (!asn1_push_tag(data, ASN1_CONTEXT(3))) goto err;
69 if (!asn1_push_tag(data, ASN1_SEQUENCE(0))) goto err;
70 if (!asn1_push_tag(data, ASN1_CONTEXT(0))) goto err;
71 if (!asn1_write_GeneralString(data,principal)) goto err;
72 if (!asn1_pop_tag(data)) goto err;
73 if (!asn1_pop_tag(data)) goto err;
74 if (!asn1_pop_tag(data)) goto err;
77 if (!asn1_pop_tag(data)) goto err;
78 if (!asn1_pop_tag(data)) goto err;
80 if (!asn1_pop_tag(data)) goto err;
82 ret = data_blob_talloc(ctx, data->data, data->length);
86 if (asn1_has_error(data)) {
87 DEBUG(1,("Failed to build negTokenInit at offset %d\n", (int)data->ofs));
96 parse a negTokenInit packet giving a GUID, a list of supported
97 OIDs (the mechanisms) and a principal name string
99 bool spnego_parse_negTokenInit(TALLOC_CTX *ctx,
101 char *OIDs[ASN1_MAX_OIDS],
109 for (i = 0; i < ASN1_MAX_OIDS; i++) {
117 *secblob = data_blob_null;
120 data = asn1_init(talloc_tos());
125 if (!asn1_load(data, blob)) goto err;
127 if (!asn1_start_tag(data,ASN1_APPLICATION(0))) goto err;
129 if (!asn1_check_OID(data,OID_SPNEGO)) goto err;
131 /* negTokenInit [0] NegTokenInit */
132 if (!asn1_start_tag(data,ASN1_CONTEXT(0))) goto err;
133 if (!asn1_start_tag(data,ASN1_SEQUENCE(0))) goto err;
135 /* mechTypes [0] MechTypeList OPTIONAL */
137 /* Not really optional, we depend on this to decide
138 * what mechanisms we have to work with. */
140 if (!asn1_start_tag(data,ASN1_CONTEXT(0))) goto err;
141 if (!asn1_start_tag(data,ASN1_SEQUENCE(0))) goto err;
142 for (i=0; asn1_tag_remaining(data) > 0 && i < ASN1_MAX_OIDS-1; i++) {
143 if (!asn1_read_OID(data,ctx, &OIDs[i])) {
146 if (asn1_has_error(data)) {
151 if (!asn1_end_tag(data)) goto err;
152 if (!asn1_end_tag(data)) goto err;
155 Win7 + Live Sign-in Assistant attaches a mechToken
156 ASN1_CONTEXT(2) to the negTokenInit packet
157 which breaks our negotiation if we just assume
158 the next tag is ASN1_CONTEXT(3).
161 if (asn1_peek_tag(data, ASN1_CONTEXT(1))) {
164 /* reqFlags [1] ContextFlags OPTIONAL */
165 if (!asn1_start_tag(data, ASN1_CONTEXT(1))) goto err;
166 if (!asn1_start_tag(data, ASN1_BIT_STRING)) goto err;
167 while (asn1_tag_remaining(data) > 0) {
168 if (!asn1_read_uint8(data, &flags)) goto err;
170 if (!asn1_end_tag(data)) goto err;
171 if (!asn1_end_tag(data)) goto err;
174 if (asn1_peek_tag(data, ASN1_CONTEXT(2))) {
175 DATA_BLOB sblob = data_blob_null;
176 /* mechToken [2] OCTET STRING OPTIONAL */
177 if (!asn1_start_tag(data, ASN1_CONTEXT(2))) goto err;
178 if (!asn1_read_OctetString(data, ctx, &sblob)) goto err;
179 if (!asn1_end_tag(data)) {
180 data_blob_free(&sblob);
186 data_blob_free(&sblob);
190 if (asn1_peek_tag(data, ASN1_CONTEXT(3))) {
192 /* mechListMIC [3] OCTET STRING OPTIONAL */
193 if (!asn1_start_tag(data, ASN1_CONTEXT(3))) goto err;
194 if (!asn1_start_tag(data, ASN1_SEQUENCE(0))) goto err;
195 if (!asn1_start_tag(data, ASN1_CONTEXT(0))) goto err;
196 if (!asn1_read_GeneralString(data, ctx, &princ)) goto err;
197 if (!asn1_end_tag(data)) goto err;
198 if (!asn1_end_tag(data)) goto err;
199 if (!asn1_end_tag(data)) goto err;
207 if (!asn1_end_tag(data)) goto err;
208 if (!asn1_end_tag(data)) goto err;
210 if (!asn1_end_tag(data)) goto err;
212 ret = !asn1_has_error(data);
216 if (asn1_has_error(data)) {
219 TALLOC_FREE(*principal);
222 data_blob_free(secblob);
224 for(j = 0; j < i && j < ASN1_MAX_OIDS-1; j++) {
225 TALLOC_FREE(OIDs[j]);
234 generate a krb5 GSS-API wrapper packet given a ticket
236 DATA_BLOB spnego_gen_krb5_wrap(TALLOC_CTX *ctx, const DATA_BLOB ticket, const uint8_t tok_id[2])
239 DATA_BLOB ret = data_blob_null;
241 data = asn1_init(talloc_tos());
243 return data_blob_null;
246 if (!asn1_push_tag(data, ASN1_APPLICATION(0))) goto err;
247 if (!asn1_write_OID(data, OID_KERBEROS5)) goto err;
249 if (!asn1_write(data, tok_id, 2)) goto err;
250 if (!asn1_write(data, ticket.data, ticket.length)) goto err;
251 if (!asn1_pop_tag(data)) goto err;
253 ret = data_blob_talloc(ctx, data->data, data->length);
257 if (asn1_has_error(data)) {
258 DEBUG(1,("Failed to build krb5 wrapper at offset %d\n", (int)data->ofs));
267 generate a SPNEGO krb5 negTokenInit packet, ready for a EXTENDED_SECURITY
268 kerberos session setup
270 int spnego_gen_krb5_negTokenInit(TALLOC_CTX *ctx,
271 const char *principal, int time_offset,
273 DATA_BLOB *session_key_krb5, uint32_t extra_ap_opts,
274 const char *ccname, time_t *expire_time)
277 DATA_BLOB tkt, tkt_wrapped;
278 const char *krb_mechs[] = {OID_KERBEROS5_OLD, OID_KERBEROS5, OID_NTLMSSP, NULL};
280 /* get a kerberos ticket for the service and extract the session key */
281 retval = cli_krb5_get_ticket(ctx, principal, time_offset,
282 &tkt, session_key_krb5,
283 extra_ap_opts, ccname,
289 /* wrap that up in a nice GSS-API wrapping */
290 tkt_wrapped = spnego_gen_krb5_wrap(ctx, tkt, TOK_ID_KRB_AP_REQ);
292 /* and wrap that in a shiny SPNEGO wrapper */
293 *targ = spnego_gen_negTokenInit(ctx, krb_mechs, &tkt_wrapped, NULL);
295 data_blob_free(&tkt_wrapped);
296 data_blob_free(&tkt);
303 parse a spnego NTLMSSP challenge packet giving two security blobs
305 bool spnego_parse_challenge(TALLOC_CTX *ctx, const DATA_BLOB blob,
306 DATA_BLOB *chal1, DATA_BLOB *chal2)
314 data = asn1_init(talloc_tos());
319 if (!asn1_load(data, blob)) goto err;
320 if (!asn1_start_tag(data,ASN1_CONTEXT(1))) goto err;
321 if (!asn1_start_tag(data,ASN1_SEQUENCE(0))) goto err;
323 if (!asn1_start_tag(data,ASN1_CONTEXT(0))) goto err;
324 if (!asn1_check_enumerated(data,1)) goto err;
325 if (!asn1_end_tag(data)) goto err;
327 if (!asn1_start_tag(data,ASN1_CONTEXT(1))) goto err;
328 if (!asn1_check_OID(data, OID_NTLMSSP)) goto err;
329 if (!asn1_end_tag(data)) goto err;
331 if (!asn1_start_tag(data,ASN1_CONTEXT(2))) goto err;
332 if (!asn1_read_OctetString(data, ctx, chal1)) goto err;
333 if (!asn1_end_tag(data)) goto err;
335 /* the second challenge is optional (XP doesn't send it) */
336 if (asn1_tag_remaining(data)) {
337 if (!asn1_start_tag(data,ASN1_CONTEXT(3))) goto err;
338 if (!asn1_read_OctetString(data, ctx, chal2)) goto err;
339 if (!asn1_end_tag(data)) goto err;
342 if (!asn1_end_tag(data)) goto err;
343 if (!asn1_end_tag(data)) goto err;
345 ret = !asn1_has_error(data);
349 if (asn1_has_error(data)) {
350 data_blob_free(chal1);
351 data_blob_free(chal2);
360 generate a SPNEGO auth packet. This will contain the encrypted passwords
362 DATA_BLOB spnego_gen_auth(TALLOC_CTX *ctx, DATA_BLOB blob)
365 DATA_BLOB ret = data_blob_null;
367 data = asn1_init(talloc_tos());
369 return data_blob_null;
372 if (!asn1_push_tag(data, ASN1_CONTEXT(1))) goto err;
373 if (!asn1_push_tag(data, ASN1_SEQUENCE(0))) goto err;
374 if (!asn1_push_tag(data, ASN1_CONTEXT(2))) goto err;
375 if (!asn1_write_OctetString(data,blob.data,blob.length)) goto err;
376 if (!asn1_pop_tag(data)) goto err;
377 if (!asn1_pop_tag(data)) goto err;
378 if (!asn1_pop_tag(data)) goto err;
380 ret = data_blob_talloc(ctx, data->data, data->length);
390 parse a SPNEGO auth packet. This contains the encrypted passwords
392 bool spnego_parse_auth_response(TALLOC_CTX *ctx,
393 DATA_BLOB blob, NTSTATUS nt_status,
401 if (NT_STATUS_IS_OK(nt_status)) {
402 negResult = SPNEGO_ACCEPT_COMPLETED;
403 } else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
404 negResult = SPNEGO_ACCEPT_INCOMPLETE;
406 negResult = SPNEGO_REJECT;
409 data = asn1_init(talloc_tos());
414 *auth = data_blob_null;
416 if (!asn1_load(data, blob)) goto err;
417 if (!asn1_start_tag(data, ASN1_CONTEXT(1))) goto err;
418 if (!asn1_start_tag(data, ASN1_SEQUENCE(0))) goto err;
419 if (!asn1_start_tag(data, ASN1_CONTEXT(0))) goto err;
420 if (!asn1_check_enumerated(data, negResult)) goto err;
421 if (!asn1_end_tag(data)) goto err;
423 if (asn1_tag_remaining(data)) {
424 if (!asn1_start_tag(data,ASN1_CONTEXT(1))) goto err;
425 if (!asn1_check_OID(data, mechOID)) goto err;
426 if (!asn1_end_tag(data)) goto err;
428 if (asn1_tag_remaining(data)) {
429 if (!asn1_start_tag(data,ASN1_CONTEXT(2))) goto err;
430 if (!asn1_read_OctetString(data, ctx, auth)) goto err;
431 if (!asn1_end_tag(data)) goto err;
433 } else if (negResult == SPNEGO_ACCEPT_INCOMPLETE) {
438 /* Binding against Win2K DC returns a duplicate of the responseToken in
439 * the optional mechListMIC field. This is a bug in Win2K. We ignore
440 * this field if it exists. Win2K8 may return a proper mechListMIC at
441 * which point we need to implement the integrity checking. */
442 if (asn1_tag_remaining(data)) {
443 DATA_BLOB mechList = data_blob_null;
444 if (!asn1_start_tag(data, ASN1_CONTEXT(3))) goto err;
445 if (!asn1_read_OctetString(data, ctx, &mechList)) goto err;
446 data_blob_free(&mechList);
447 if (!asn1_end_tag(data)) goto err;
448 DEBUG(5,("spnego_parse_auth_response received mechListMIC, "
452 if (!asn1_end_tag(data)) goto err;
453 if (!asn1_end_tag(data)) goto err;
455 ret = !asn1_has_error(data);
459 if (asn1_has_error(data)) {
460 DEBUG(3,("spnego_parse_auth_response failed at %d\n", (int)data->ofs));
462 data_blob_free(auth);