2 Unix SMB/CIFS implementation.
4 dcerpc schannel operations
6 Copyright (C) Andrew Tridgell 2004
7 Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
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/>.
25 #include "lib/util/tevent_ntstatus.h"
26 #include "librpc/gen_ndr/ndr_schannel.h"
27 #include "auth/auth.h"
28 #include "auth/credentials/credentials.h"
29 #include "auth/gensec/gensec.h"
30 #include "auth/gensec/gensec_internal.h"
31 #include "auth/gensec/gensec_proto.h"
32 #include "../libcli/auth/schannel.h"
33 #include "librpc/gen_ndr/dcerpc.h"
34 #include "param/param.h"
35 #include "auth/gensec/gensec_toplevel_proto.h"
36 #include "lib/crypto/crypto.h"
38 struct schannel_state {
39 struct gensec_security *gensec;
42 struct netlogon_creds_CredentialState *creds;
43 struct auth_user_info_dc *user_info_dc;
46 #define SETUP_SEQNUM(state, buf, initiator) do { \
47 uint8_t *_buf = buf; \
48 uint32_t _seq_num_low = (state)->seq_num & UINT32_MAX; \
49 uint32_t _seq_num_high = (state)->seq_num >> 32; \
51 _seq_num_high |= 0x80000000; \
53 RSIVAL(_buf, 0, _seq_num_low); \
54 RSIVAL(_buf, 4, _seq_num_high); \
57 static struct schannel_state *netsec_create_state(
58 struct gensec_security *gensec,
59 struct netlogon_creds_CredentialState *creds,
62 struct schannel_state *state;
64 state = talloc_zero(gensec, struct schannel_state);
69 state->gensec = gensec;
70 state->initiator = initiator;
71 state->creds = netlogon_creds_copy(state, creds);
72 if (state->creds == NULL) {
77 gensec->private_data = state;
82 static void netsec_offset_and_sizes(struct schannel_state *state,
84 uint32_t *_min_sig_size,
85 uint32_t *_used_sig_size,
86 uint32_t *_checksum_length,
87 uint32_t *_confounder_ofs)
89 uint32_t min_sig_size;
90 uint32_t used_sig_size;
91 uint32_t checksum_length;
92 uint32_t confounder_ofs;
94 if (state->creds->negotiate_flags & NETLOGON_NEG_SUPPORTS_AES) {
98 * Note: windows has a bug here and uses the old values...
100 * checksum_length = 32;
101 * confounder_ofs = 48;
117 *_min_sig_size = min_sig_size;
120 if (_used_sig_size) {
121 *_used_sig_size = used_sig_size;
124 if (_checksum_length) {
125 *_checksum_length = checksum_length;
128 if (_confounder_ofs) {
129 *_confounder_ofs = confounder_ofs;
133 /*******************************************************************
134 Encode or Decode the sequence number (which is symmetric)
135 ********************************************************************/
136 static void netsec_do_seq_num(struct schannel_state *state,
137 const uint8_t *checksum,
138 uint32_t checksum_length,
141 if (state->creds->negotiate_flags & NETLOGON_NEG_SUPPORTS_AES) {
143 uint8_t iv[AES_BLOCK_SIZE];
145 AES_set_encrypt_key(state->creds->session_key, 128, &key);
147 memcpy(iv+0, checksum, 8);
148 memcpy(iv+8, checksum, 8);
150 aes_cfb8_encrypt(seq_num, seq_num, 8, &key, iv, AES_ENCRYPT);
152 static const uint8_t zeros[4];
153 uint8_t sequence_key[16];
156 hmac_md5(state->creds->session_key, zeros, sizeof(zeros), digest1);
157 hmac_md5(digest1, checksum, checksum_length, sequence_key);
158 arcfour_crypt(seq_num, sequence_key, 8);
164 static void netsec_do_seal(struct schannel_state *state,
165 const uint8_t seq_num[8],
166 uint8_t confounder[8],
167 uint8_t *data, uint32_t length,
170 if (state->creds->negotiate_flags & NETLOGON_NEG_SUPPORTS_AES) {
172 uint8_t iv[AES_BLOCK_SIZE];
173 uint8_t sess_kf0[16];
176 for (i = 0; i < 16; i++) {
177 sess_kf0[i] = state->creds->session_key[i] ^ 0xf0;
180 AES_set_encrypt_key(sess_kf0, 128, &key);
182 memcpy(iv+0, seq_num, 8);
183 memcpy(iv+8, seq_num, 8);
186 aes_cfb8_encrypt(confounder, confounder, 8, &key, iv, AES_ENCRYPT);
187 aes_cfb8_encrypt(data, data, length, &key, iv, AES_ENCRYPT);
189 aes_cfb8_encrypt(confounder, confounder, 8, &key, iv, AES_DECRYPT);
190 aes_cfb8_encrypt(data, data, length, &key, iv, AES_DECRYPT);
193 uint8_t sealing_key[16];
194 static const uint8_t zeros[4];
196 uint8_t sess_kf0[16];
199 for (i = 0; i < 16; i++) {
200 sess_kf0[i] = state->creds->session_key[i] ^ 0xf0;
203 hmac_md5(sess_kf0, zeros, 4, digest2);
204 hmac_md5(digest2, seq_num, 8, sealing_key);
206 arcfour_crypt(confounder, sealing_key, 8);
207 arcfour_crypt(data, sealing_key, length);
211 /*******************************************************************
212 Create a digest over the entire packet (including the data), and
213 MD5 it with the session key.
214 ********************************************************************/
215 static void netsec_do_sign(struct schannel_state *state,
216 const uint8_t *confounder,
217 const uint8_t *data, size_t length,
221 if (state->creds->negotiate_flags & NETLOGON_NEG_SUPPORTS_AES) {
222 struct HMACSHA256Context ctx;
224 hmac_sha256_init(state->creds->session_key,
225 sizeof(state->creds->session_key),
229 SSVAL(header, 0, NL_SIGN_HMAC_SHA256);
230 SSVAL(header, 2, NL_SEAL_AES128);
231 SSVAL(header, 4, 0xFFFF);
232 SSVAL(header, 6, 0x0000);
234 hmac_sha256_update(header, 8, &ctx);
235 hmac_sha256_update(confounder, 8, &ctx);
237 SSVAL(header, 0, NL_SIGN_HMAC_SHA256);
238 SSVAL(header, 2, NL_SEAL_NONE);
239 SSVAL(header, 4, 0xFFFF);
240 SSVAL(header, 6, 0x0000);
242 hmac_sha256_update(header, 8, &ctx);
245 hmac_sha256_update(data, length, &ctx);
247 hmac_sha256_final(checksum, &ctx);
249 uint8_t packet_digest[16];
250 static const uint8_t zeros[4];
254 MD5Update(&ctx, zeros, 4);
256 SSVAL(header, 0, NL_SIGN_HMAC_MD5);
257 SSVAL(header, 2, NL_SEAL_RC4);
258 SSVAL(header, 4, 0xFFFF);
259 SSVAL(header, 6, 0x0000);
261 MD5Update(&ctx, header, 8);
262 MD5Update(&ctx, confounder, 8);
264 SSVAL(header, 0, NL_SIGN_HMAC_MD5);
265 SSVAL(header, 2, NL_SEAL_NONE);
266 SSVAL(header, 4, 0xFFFF);
267 SSVAL(header, 6, 0x0000);
269 MD5Update(&ctx, header, 8);
271 MD5Update(&ctx, data, length);
272 MD5Final(packet_digest, &ctx);
274 hmac_md5(state->creds->session_key,
275 packet_digest, sizeof(packet_digest),
280 static NTSTATUS netsec_incoming_packet(struct schannel_state *state,
282 uint8_t *data, size_t length,
283 const uint8_t *whole_pdu, size_t pdu_length,
284 const DATA_BLOB *sig)
286 uint32_t min_sig_size = 0;
288 uint8_t checksum[32];
289 uint32_t checksum_length = sizeof(checksum_length);
290 uint8_t _confounder[8];
291 uint8_t *confounder = NULL;
292 uint32_t confounder_ofs = 0;
295 const uint8_t *sign_data = NULL;
296 size_t sign_length = 0;
298 netsec_offset_and_sizes(state,
305 if (sig->length < min_sig_size) {
306 return NT_STATUS_ACCESS_DENIED;
310 confounder = _confounder;
311 memcpy(confounder, sig->data+confounder_ofs, 8);
316 SETUP_SEQNUM(state, seq_num, !state->initiator);
319 netsec_do_seal(state, seq_num,
325 if (state->gensec->want_features & GENSEC_FEATURE_SIGN_PKT_HEADER) {
326 sign_data = whole_pdu;
327 sign_length = pdu_length;
330 sign_length = length;
333 netsec_do_sign(state, confounder,
334 sign_data, sign_length,
337 ret = memcmp(checksum, sig->data+16, checksum_length);
339 dump_data_pw("calc digest:", checksum, checksum_length);
340 dump_data_pw("wire digest:", sig->data+16, checksum_length);
341 return NT_STATUS_ACCESS_DENIED;
344 netsec_do_seq_num(state, checksum, checksum_length, seq_num);
346 ret = memcmp(seq_num, sig->data+8, 8);
348 dump_data_pw("calc seq num:", seq_num, 8);
349 dump_data_pw("wire seq num:", sig->data+8, 8);
350 return NT_STATUS_ACCESS_DENIED;
356 static uint32_t netsec_outgoing_sig_size(struct schannel_state *state)
358 uint32_t sig_size = 0;
360 netsec_offset_and_sizes(state,
370 static NTSTATUS netsec_outgoing_packet(struct schannel_state *state,
373 uint8_t *data, size_t length,
374 const uint8_t *whole_pdu, size_t pdu_length,
377 uint32_t min_sig_size = 0;
378 uint32_t used_sig_size = 0;
380 uint8_t checksum[32];
381 uint32_t checksum_length = sizeof(checksum_length);
382 uint8_t _confounder[8];
383 uint8_t *confounder = NULL;
384 uint32_t confounder_ofs = 0;
386 const uint8_t *sign_data = NULL;
387 size_t sign_length = 0;
389 netsec_offset_and_sizes(state,
396 SETUP_SEQNUM(state, seq_num, state->initiator);
399 confounder = _confounder;
400 generate_random_buffer(confounder, 8);
405 if (state->gensec->want_features & GENSEC_FEATURE_SIGN_PKT_HEADER) {
406 sign_data = whole_pdu;
407 sign_length = pdu_length;
410 sign_length = length;
413 netsec_do_sign(state, confounder,
414 sign_data, sign_length,
418 netsec_do_seal(state, seq_num,
424 netsec_do_seq_num(state, checksum, checksum_length, seq_num);
426 (*sig) = data_blob_talloc_zero(mem_ctx, used_sig_size);
428 memcpy(sig->data, header, 8);
429 memcpy(sig->data+8, seq_num, 8);
430 memcpy(sig->data+16, checksum, checksum_length);
433 memcpy(sig->data+confounder_ofs, confounder, 8);
436 dump_data_pw("signature:", sig->data+ 0, 8);
437 dump_data_pw("seq_num :", sig->data+ 8, 8);
438 dump_data_pw("digest :", sig->data+16, checksum_length);
439 dump_data_pw("confound :", sig->data+confounder_ofs, 8);
444 _PUBLIC_ NTSTATUS gensec_schannel_init(TALLOC_CTX *ctx);
446 static size_t schannel_sig_size(struct gensec_security *gensec_security, size_t data_size)
448 struct schannel_state *state =
449 talloc_get_type_abort(gensec_security->private_data,
450 struct schannel_state);
452 return netsec_outgoing_sig_size(state);
455 struct schannel_update_state {
460 static NTSTATUS schannel_update_internal(struct gensec_security *gensec_security,
461 TALLOC_CTX *out_mem_ctx,
462 const DATA_BLOB in, DATA_BLOB *out);
464 static struct tevent_req *schannel_update_send(TALLOC_CTX *mem_ctx,
465 struct tevent_context *ev,
466 struct gensec_security *gensec_security,
469 struct tevent_req *req;
470 struct schannel_update_state *state = NULL;
473 req = tevent_req_create(mem_ctx, &state,
474 struct schannel_update_state);
479 status = schannel_update_internal(gensec_security,
482 state->status = status;
483 if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
484 status = NT_STATUS_OK;
486 if (tevent_req_nterror(req, status)) {
487 return tevent_req_post(req, ev);
490 tevent_req_done(req);
491 return tevent_req_post(req, ev);
494 static NTSTATUS schannel_update_internal(struct gensec_security *gensec_security,
495 TALLOC_CTX *out_mem_ctx,
496 const DATA_BLOB in, DATA_BLOB *out)
498 struct schannel_state *state =
499 talloc_get_type(gensec_security->private_data,
500 struct schannel_state);
502 enum ndr_err_code ndr_err;
503 struct NL_AUTH_MESSAGE bind_schannel = {};
504 struct NL_AUTH_MESSAGE bind_schannel_ack;
505 struct netlogon_creds_CredentialState *creds;
506 const char *workstation;
509 *out = data_blob(NULL, 0);
511 if (gensec_security->dcerpc_auth_level < DCERPC_AUTH_LEVEL_INTEGRITY) {
512 switch (gensec_security->gensec_role) {
514 return NT_STATUS_INVALID_PARAMETER_MIX;
516 return NT_STATUS_INVALID_PARAMETER;
518 return NT_STATUS_INTERNAL_ERROR;
521 switch (gensec_security->gensec_role) {
524 /* we could parse the bind ack, but we don't know what it is yet */
528 creds = cli_credentials_get_netlogon_creds(gensec_security->credentials);
530 return NT_STATUS_INVALID_PARAMETER_MIX;
533 state = netsec_create_state(gensec_security,
534 creds, true /* initiator */);
536 return NT_STATUS_NO_MEMORY;
539 bind_schannel.MessageType = NL_NEGOTIATE_REQUEST;
541 bind_schannel.Flags = NL_FLAG_OEM_NETBIOS_DOMAIN_NAME |
542 NL_FLAG_OEM_NETBIOS_COMPUTER_NAME;
543 bind_schannel.oem_netbios_domain.a = cli_credentials_get_domain(gensec_security->credentials);
544 bind_schannel.oem_netbios_computer.a = creds->computer_name;
546 if (creds->secure_channel_type == SEC_CHAN_DNS_DOMAIN) {
547 bind_schannel.Flags |= NL_FLAG_UTF8_DNS_DOMAIN_NAME;
548 bind_schannel.utf8_dns_domain.u = cli_credentials_get_realm(gensec_security->credentials);
550 bind_schannel.Flags |= NL_FLAG_UTF8_NETBIOS_COMPUTER_NAME;
551 bind_schannel.utf8_netbios_computer.u = creds->computer_name;
554 ndr_err = ndr_push_struct_blob(out, out_mem_ctx, &bind_schannel,
555 (ndr_push_flags_fn_t)ndr_push_NL_AUTH_MESSAGE);
556 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
557 status = ndr_map_error2ntstatus(ndr_err);
558 DEBUG(3, ("Could not create schannel bind: %s\n",
563 return NT_STATUS_MORE_PROCESSING_REQUIRED;
567 /* no third leg on this protocol */
568 return NT_STATUS_INVALID_PARAMETER;
571 /* parse the schannel startup blob */
572 ndr_err = ndr_pull_struct_blob(&in, out_mem_ctx, &bind_schannel,
573 (ndr_pull_flags_fn_t)ndr_pull_NL_AUTH_MESSAGE);
574 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
575 status = ndr_map_error2ntstatus(ndr_err);
576 DEBUG(3, ("Could not parse incoming schannel bind: %s\n",
581 if (bind_schannel.Flags & NL_FLAG_OEM_NETBIOS_DOMAIN_NAME) {
582 domain = bind_schannel.oem_netbios_domain.a;
583 if (strcasecmp_m(domain, lpcfg_workgroup(gensec_security->settings->lp_ctx)) != 0) {
584 DEBUG(3, ("Request for schannel to incorrect domain: %s != our domain %s\n",
585 domain, lpcfg_workgroup(gensec_security->settings->lp_ctx)));
586 return NT_STATUS_LOGON_FAILURE;
588 } else if (bind_schannel.Flags & NL_FLAG_UTF8_DNS_DOMAIN_NAME) {
589 domain = bind_schannel.utf8_dns_domain.u;
590 if (strcasecmp_m(domain, lpcfg_dnsdomain(gensec_security->settings->lp_ctx)) != 0) {
591 DEBUG(3, ("Request for schannel to incorrect domain: %s != our domain %s\n",
592 domain, lpcfg_dnsdomain(gensec_security->settings->lp_ctx)));
593 return NT_STATUS_LOGON_FAILURE;
596 DEBUG(3, ("Request for schannel to without domain\n"));
597 return NT_STATUS_LOGON_FAILURE;
600 if (bind_schannel.Flags & NL_FLAG_OEM_NETBIOS_COMPUTER_NAME) {
601 workstation = bind_schannel.oem_netbios_computer.a;
602 } else if (bind_schannel.Flags & NL_FLAG_UTF8_NETBIOS_COMPUTER_NAME) {
603 workstation = bind_schannel.utf8_netbios_computer.u;
605 DEBUG(3, ("Request for schannel to without netbios workstation\n"));
606 return NT_STATUS_LOGON_FAILURE;
609 status = schannel_get_creds_state(out_mem_ctx,
610 gensec_security->settings->lp_ctx,
611 workstation, &creds);
612 if (!NT_STATUS_IS_OK(status)) {
613 DEBUG(3, ("Could not find session key for attempted schannel connection from %s: %s\n",
614 workstation, nt_errstr(status)));
615 if (NT_STATUS_EQUAL(status, NT_STATUS_INVALID_HANDLE)) {
616 return NT_STATUS_LOGON_FAILURE;
621 state = netsec_create_state(gensec_security,
622 creds, false /* not initiator */);
624 return NT_STATUS_NO_MEMORY;
627 status = auth_anonymous_user_info_dc(state,
628 lpcfg_netbios_name(gensec_security->settings->lp_ctx),
629 &state->user_info_dc);
630 if (!NT_STATUS_IS_OK(status)) {
634 bind_schannel_ack.MessageType = NL_NEGOTIATE_RESPONSE;
635 bind_schannel_ack.Flags = 0;
636 bind_schannel_ack.Buffer.dummy = 0x6c0000; /* actually I think
641 ndr_err = ndr_push_struct_blob(out, out_mem_ctx, &bind_schannel_ack,
642 (ndr_push_flags_fn_t)ndr_push_NL_AUTH_MESSAGE);
643 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
644 status = ndr_map_error2ntstatus(ndr_err);
645 DEBUG(3, ("Could not return schannel bind ack for client %s: %s\n",
646 workstation, nt_errstr(status)));
652 return NT_STATUS_INVALID_PARAMETER;
655 static NTSTATUS schannel_update_recv(struct tevent_req *req,
656 TALLOC_CTX *out_mem_ctx,
659 struct schannel_update_state *state =
661 struct schannel_update_state);
664 *out = data_blob_null;
666 if (tevent_req_is_nterror(req, &status)) {
667 tevent_req_received(req);
671 status = state->status;
672 talloc_steal(out_mem_ctx, state->out.data);
674 tevent_req_received(req);
679 * Returns anonymous credentials for schannel, matching Win2k3.
683 static NTSTATUS schannel_session_info(struct gensec_security *gensec_security,
685 struct auth_session_info **_session_info)
687 struct schannel_state *state =
688 talloc_get_type(gensec_security->private_data,
689 struct schannel_state);
690 struct auth4_context *auth_ctx = gensec_security->auth_context;
691 struct auth_session_info *session_info = NULL;
692 uint32_t session_info_flags = 0;
695 if (auth_ctx == NULL) {
696 DEBUG(0, ("Cannot generate a session_info without the auth_context\n"));
697 return NT_STATUS_INTERNAL_ERROR;
700 if (auth_ctx->generate_session_info == NULL) {
701 DEBUG(0, ("Cannot generate a session_info without the generate_session_info hook\n"));
702 return NT_STATUS_INTERNAL_ERROR;
705 if (gensec_security->want_features & GENSEC_FEATURE_UNIX_TOKEN) {
706 session_info_flags |= AUTH_SESSION_INFO_UNIX_TOKEN;
709 session_info_flags |= AUTH_SESSION_INFO_SIMPLE_PRIVILEGES;
711 status = auth_ctx->generate_session_info(
715 state->user_info_dc->info->account_name,
718 if (!NT_STATUS_IS_OK(status)) {
722 *_session_info = session_info;
726 static NTSTATUS schannel_server_start(struct gensec_security *gensec_security)
731 static NTSTATUS schannel_client_start(struct gensec_security *gensec_security)
736 static bool schannel_have_feature(struct gensec_security *gensec_security,
739 if (gensec_security->dcerpc_auth_level >= DCERPC_AUTH_LEVEL_INTEGRITY) {
740 if (feature & GENSEC_FEATURE_SIGN) {
744 if (gensec_security->dcerpc_auth_level == DCERPC_AUTH_LEVEL_PRIVACY) {
745 if (feature & GENSEC_FEATURE_SEAL) {
749 if (feature & GENSEC_FEATURE_DCE_STYLE) {
752 if (feature & GENSEC_FEATURE_SIGN_PKT_HEADER) {
761 static NTSTATUS schannel_unseal_packet(struct gensec_security *gensec_security,
762 uint8_t *data, size_t length,
763 const uint8_t *whole_pdu, size_t pdu_length,
764 const DATA_BLOB *sig)
766 struct schannel_state *state =
767 talloc_get_type_abort(gensec_security->private_data,
768 struct schannel_state);
770 return netsec_incoming_packet(state, true,
771 discard_const_p(uint8_t, data),
773 whole_pdu, pdu_length,
778 check the signature on a packet
780 static NTSTATUS schannel_check_packet(struct gensec_security *gensec_security,
781 const uint8_t *data, size_t length,
782 const uint8_t *whole_pdu, size_t pdu_length,
783 const DATA_BLOB *sig)
785 struct schannel_state *state =
786 talloc_get_type_abort(gensec_security->private_data,
787 struct schannel_state);
789 return netsec_incoming_packet(state, false,
790 discard_const_p(uint8_t, data),
792 whole_pdu, pdu_length,
798 static NTSTATUS schannel_seal_packet(struct gensec_security *gensec_security,
800 uint8_t *data, size_t length,
801 const uint8_t *whole_pdu, size_t pdu_length,
804 struct schannel_state *state =
805 talloc_get_type_abort(gensec_security->private_data,
806 struct schannel_state);
808 return netsec_outgoing_packet(state, mem_ctx, true,
810 whole_pdu, pdu_length,
817 static NTSTATUS schannel_sign_packet(struct gensec_security *gensec_security,
819 const uint8_t *data, size_t length,
820 const uint8_t *whole_pdu, size_t pdu_length,
823 struct schannel_state *state =
824 talloc_get_type_abort(gensec_security->private_data,
825 struct schannel_state);
827 return netsec_outgoing_packet(state, mem_ctx, false,
828 discard_const_p(uint8_t, data),
830 whole_pdu, pdu_length,
834 static const struct gensec_security_ops gensec_schannel_security_ops = {
836 .auth_type = DCERPC_AUTH_TYPE_SCHANNEL,
837 .client_start = schannel_client_start,
838 .server_start = schannel_server_start,
839 .update_send = schannel_update_send,
840 .update_recv = schannel_update_recv,
841 .seal_packet = schannel_seal_packet,
842 .sign_packet = schannel_sign_packet,
843 .check_packet = schannel_check_packet,
844 .unseal_packet = schannel_unseal_packet,
845 .session_info = schannel_session_info,
846 .sig_size = schannel_sig_size,
847 .have_feature = schannel_have_feature,
849 .priority = GENSEC_SCHANNEL
852 _PUBLIC_ NTSTATUS gensec_schannel_init(TALLOC_CTX *ctx)
855 ret = gensec_register(&gensec_schannel_security_ops);
856 if (!NT_STATUS_IS_OK(ret)) {
857 DEBUG(0,("Failed to register '%s' gensec backend!\n",
858 gensec_schannel_security_ops.name));