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)
42 data = asn1_init(talloc_tos());
44 return data_blob_null;
47 asn1_push_tag(data,ASN1_APPLICATION(0));
48 asn1_write_OID(data,OID_SPNEGO);
49 asn1_push_tag(data,ASN1_CONTEXT(0));
50 asn1_push_tag(data,ASN1_SEQUENCE(0));
52 asn1_push_tag(data,ASN1_CONTEXT(0));
53 asn1_push_tag(data,ASN1_SEQUENCE(0));
54 for (i=0; OIDs[i]; i++) {
55 asn1_write_OID(data,OIDs[i]);
60 if (psecblob && psecblob->length && psecblob->data) {
61 asn1_push_tag(data, ASN1_CONTEXT(2));
62 asn1_write_OctetString(data,psecblob->data,
68 asn1_push_tag(data, ASN1_CONTEXT(3));
69 asn1_push_tag(data, ASN1_SEQUENCE(0));
70 asn1_push_tag(data, ASN1_CONTEXT(0));
71 asn1_write_GeneralString(data,principal);
82 if (data->has_error) {
83 DEBUG(1,("Failed to build negTokenInit at offset %d\n", (int)data->ofs));
86 ret = data_blob_talloc(ctx, data->data, data->length);
93 parse a negTokenInit packet giving a GUID, a list of supported
94 OIDs (the mechanisms) and a principal name string
96 bool spnego_parse_negTokenInit(TALLOC_CTX *ctx,
98 char *OIDs[ASN1_MAX_OIDS],
106 data = asn1_init(talloc_tos());
111 asn1_load(data, blob);
113 asn1_start_tag(data,ASN1_APPLICATION(0));
115 asn1_check_OID(data,OID_SPNEGO);
117 /* negTokenInit [0] NegTokenInit */
118 asn1_start_tag(data,ASN1_CONTEXT(0));
119 asn1_start_tag(data,ASN1_SEQUENCE(0));
121 /* mechTypes [0] MechTypeList OPTIONAL */
123 /* Not really optional, we depend on this to decide
124 * what mechanisms we have to work with. */
126 asn1_start_tag(data,ASN1_CONTEXT(0));
127 asn1_start_tag(data,ASN1_SEQUENCE(0));
128 for (i=0; asn1_tag_remaining(data) > 0 && i < ASN1_MAX_OIDS-1; i++) {
129 if (!asn1_read_OID(data,ctx, &OIDs[i])) {
132 if (data->has_error) {
144 *secblob = data_blob_null;
148 Win7 + Live Sign-in Assistant attaches a mechToken
149 ASN1_CONTEXT(2) to the negTokenInit packet
150 which breaks our negotiation if we just assume
151 the next tag is ASN1_CONTEXT(3).
154 if (asn1_peek_tag(data, ASN1_CONTEXT(1))) {
157 /* reqFlags [1] ContextFlags OPTIONAL */
158 asn1_start_tag(data, ASN1_CONTEXT(1));
159 asn1_start_tag(data, ASN1_BIT_STRING);
160 while (asn1_tag_remaining(data) > 0) {
161 asn1_read_uint8(data, &flags);
167 if (asn1_peek_tag(data, ASN1_CONTEXT(2))) {
168 DATA_BLOB sblob = data_blob_null;
169 /* mechToken [2] OCTET STRING OPTIONAL */
170 asn1_start_tag(data, ASN1_CONTEXT(2));
171 asn1_read_OctetString(data, ctx, &sblob);
176 data_blob_free(&sblob);
180 if (asn1_peek_tag(data, ASN1_CONTEXT(3))) {
182 /* mechListMIC [3] OCTET STRING OPTIONAL */
183 asn1_start_tag(data, ASN1_CONTEXT(3));
184 asn1_start_tag(data, ASN1_SEQUENCE(0));
185 asn1_start_tag(data, ASN1_CONTEXT(0));
186 asn1_read_GeneralString(data, ctx, &princ);
202 ret = !data->has_error;
203 if (data->has_error) {
206 TALLOC_FREE(*principal);
209 data_blob_free(secblob);
211 for(j = 0; j < i && j < ASN1_MAX_OIDS-1; j++) {
212 TALLOC_FREE(OIDs[j]);
221 generate a krb5 GSS-API wrapper packet given a ticket
223 DATA_BLOB spnego_gen_krb5_wrap(TALLOC_CTX *ctx, const DATA_BLOB ticket, const uint8 tok_id[2])
228 data = asn1_init(talloc_tos());
230 return data_blob_null;
233 asn1_push_tag(data, ASN1_APPLICATION(0));
234 asn1_write_OID(data, OID_KERBEROS5);
236 asn1_write(data, tok_id, 2);
237 asn1_write(data, ticket.data, ticket.length);
240 if (data->has_error) {
241 DEBUG(1,("Failed to build krb5 wrapper at offset %d\n", (int)data->ofs));
244 ret = data_blob_talloc(ctx, data->data, data->length);
251 parse a krb5 GSS-API wrapper packet giving a ticket
253 bool spnego_parse_krb5_wrap(TALLOC_CTX *ctx, DATA_BLOB blob, DATA_BLOB *ticket, uint8 tok_id[2])
259 data = asn1_init(talloc_tos());
264 asn1_load(data, blob);
265 asn1_start_tag(data, ASN1_APPLICATION(0));
266 asn1_check_OID(data, OID_KERBEROS5);
268 data_remaining = asn1_tag_remaining(data);
270 if (data_remaining < 3) {
271 data->has_error = True;
273 asn1_read(data, tok_id, 2);
275 *ticket = data_blob_talloc(ctx, NULL, data_remaining);
276 asn1_read(data, ticket->data, ticket->length);
281 ret = !data->has_error;
283 if (data->has_error) {
284 data_blob_free(ticket);
294 generate a SPNEGO krb5 negTokenInit packet, ready for a EXTENDED_SECURITY
295 kerberos session setup
297 int spnego_gen_krb5_negTokenInit(TALLOC_CTX *ctx,
298 const char *principal, int time_offset,
300 DATA_BLOB *session_key_krb5, uint32 extra_ap_opts,
304 DATA_BLOB tkt, tkt_wrapped;
305 const char *krb_mechs[] = {OID_KERBEROS5_OLD, OID_KERBEROS5, OID_NTLMSSP, NULL};
307 /* get a kerberos ticket for the service and extract the session key */
308 retval = cli_krb5_get_ticket(ctx, principal, time_offset,
309 &tkt, session_key_krb5,
316 /* wrap that up in a nice GSS-API wrapping */
317 tkt_wrapped = spnego_gen_krb5_wrap(ctx, tkt, TOK_ID_KRB_AP_REQ);
319 /* and wrap that in a shiny SPNEGO wrapper */
320 *targ = spnego_gen_negTokenInit(ctx, krb_mechs, &tkt_wrapped, NULL);
322 data_blob_free(&tkt_wrapped);
323 data_blob_free(&tkt);
330 parse a spnego NTLMSSP challenge packet giving two security blobs
332 bool spnego_parse_challenge(TALLOC_CTX *ctx, const DATA_BLOB blob,
333 DATA_BLOB *chal1, DATA_BLOB *chal2)
341 data = asn1_init(talloc_tos());
346 asn1_load(data, blob);
347 asn1_start_tag(data,ASN1_CONTEXT(1));
348 asn1_start_tag(data,ASN1_SEQUENCE(0));
350 asn1_start_tag(data,ASN1_CONTEXT(0));
351 asn1_check_enumerated(data,1);
354 asn1_start_tag(data,ASN1_CONTEXT(1));
355 asn1_check_OID(data, OID_NTLMSSP);
358 asn1_start_tag(data,ASN1_CONTEXT(2));
359 asn1_read_OctetString(data, ctx, chal1);
362 /* the second challenge is optional (XP doesn't send it) */
363 if (asn1_tag_remaining(data)) {
364 asn1_start_tag(data,ASN1_CONTEXT(3));
365 asn1_read_OctetString(data, ctx, chal2);
372 ret = !data->has_error;
374 if (data->has_error) {
375 data_blob_free(chal1);
376 data_blob_free(chal2);
385 generate a SPNEGO auth packet. This will contain the encrypted passwords
387 DATA_BLOB spnego_gen_auth(TALLOC_CTX *ctx, DATA_BLOB blob)
392 data = asn1_init(talloc_tos());
394 return data_blob_null;
397 asn1_push_tag(data, ASN1_CONTEXT(1));
398 asn1_push_tag(data, ASN1_SEQUENCE(0));
399 asn1_push_tag(data, ASN1_CONTEXT(2));
400 asn1_write_OctetString(data,blob.data,blob.length);
405 ret = data_blob_talloc(ctx, data->data, data->length);
413 parse a SPNEGO auth packet. This contains the encrypted passwords
415 bool spnego_parse_auth_response(TALLOC_CTX *ctx,
416 DATA_BLOB blob, NTSTATUS nt_status,
423 if (NT_STATUS_IS_OK(nt_status)) {
424 negResult = SPNEGO_ACCEPT_COMPLETED;
425 } else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
426 negResult = SPNEGO_ACCEPT_INCOMPLETE;
428 negResult = SPNEGO_REJECT;
431 data = asn1_init(talloc_tos());
436 asn1_load(data, blob);
437 asn1_start_tag(data, ASN1_CONTEXT(1));
438 asn1_start_tag(data, ASN1_SEQUENCE(0));
439 asn1_start_tag(data, ASN1_CONTEXT(0));
440 asn1_check_enumerated(data, negResult);
443 *auth = data_blob_null;
445 if (asn1_tag_remaining(data)) {
446 asn1_start_tag(data,ASN1_CONTEXT(1));
447 asn1_check_OID(data, mechOID);
450 if (asn1_tag_remaining(data)) {
451 asn1_start_tag(data,ASN1_CONTEXT(2));
452 asn1_read_OctetString(data, ctx, auth);
455 } else if (negResult == SPNEGO_ACCEPT_INCOMPLETE) {
459 /* Binding against Win2K DC returns a duplicate of the responseToken in
460 * the optional mechListMIC field. This is a bug in Win2K. We ignore
461 * this field if it exists. Win2K8 may return a proper mechListMIC at
462 * which point we need to implement the integrity checking. */
463 if (asn1_tag_remaining(data)) {
464 DATA_BLOB mechList = data_blob_null;
465 asn1_start_tag(data, ASN1_CONTEXT(3));
466 asn1_read_OctetString(data, ctx, &mechList);
468 data_blob_free(&mechList);
469 DEBUG(5,("spnego_parse_auth_response received mechListMIC, "
476 if (data->has_error) {
477 DEBUG(3,("spnego_parse_auth_response failed at %d\n", (int)data->ofs));
479 data_blob_free(auth);