1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) Steve Holme, <steve_holme@hotmail.com>.
9 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
10 *
11 * This software is licensed as described in the file COPYING, which
12 * you should have received as part of this distribution. The terms
13 * are also available at https://curl.se/docs/copyright.html.
14 *
15 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
16 * copies of the Software, and permit persons to whom the Software is
17 * furnished to do so, under the terms of the COPYING file.
18 *
19 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
20 * KIND, either express or implied.
21 *
22 * SPDX-License-Identifier: curl
23 *
24 * RFC2831 DIGEST-MD5 authentication
25 *
26 ***************************************************************************/
27
28 #include "curl_setup.h"
29
30 #if defined(USE_WINDOWS_SSPI) && !defined(CURL_DISABLE_DIGEST_AUTH)
31
32 #include <curl/curl.h>
33
34 #include "vauth/vauth.h"
35 #include "vauth/digest.h"
36 #include "urldata.h"
37 #include "warnless.h"
38 #include "curl_multibyte.h"
39 #include "sendf.h"
40 #include "strdup.h"
41 #include "strcase.h"
42 #include "strerror.h"
43
44 /* The last #include files should be: */
45 #include "curl_memory.h"
46 #include "memdebug.h"
47
48 /*
49 * Curl_auth_is_digest_supported()
50 *
51 * This is used to evaluate if DIGEST is supported.
52 *
53 * Parameters: None
54 *
55 * Returns TRUE if DIGEST is supported by Windows SSPI.
56 */
Curl_auth_is_digest_supported(void)57 bool Curl_auth_is_digest_supported(void)
58 {
59 PSecPkgInfo SecurityPackage;
60 SECURITY_STATUS status;
61
62 /* Query the security package for Digest */
63 status = s_pSecFn->QuerySecurityPackageInfo((TCHAR *) TEXT(SP_NAME_DIGEST),
64 &SecurityPackage);
65
66 /* Release the package buffer as it is not required anymore */
67 if(status == SEC_E_OK) {
68 s_pSecFn->FreeContextBuffer(SecurityPackage);
69 }
70
71 return (status == SEC_E_OK ? TRUE : FALSE);
72 }
73
74 /*
75 * Curl_auth_create_digest_md5_message()
76 *
77 * This is used to generate an already encoded DIGEST-MD5 response message
78 * ready for sending to the recipient.
79 *
80 * Parameters:
81 *
82 * data [in] - The session handle.
83 * chlg [in] - The challenge message.
84 * userp [in] - The user name in the format User or Domain\User.
85 * passwdp [in] - The user's password.
86 * service [in] - The service type such as http, smtp, pop or imap.
87 * out [out] - The result storage.
88 *
89 * Returns CURLE_OK on success.
90 */
Curl_auth_create_digest_md5_message(struct Curl_easy * data,const struct bufref * chlg,const char * userp,const char * passwdp,const char * service,struct bufref * out)91 CURLcode Curl_auth_create_digest_md5_message(struct Curl_easy *data,
92 const struct bufref *chlg,
93 const char *userp,
94 const char *passwdp,
95 const char *service,
96 struct bufref *out)
97 {
98 CURLcode result = CURLE_OK;
99 TCHAR *spn = NULL;
100 size_t token_max = 0;
101 unsigned char *output_token = NULL;
102 CredHandle credentials;
103 CtxtHandle context;
104 PSecPkgInfo SecurityPackage;
105 SEC_WINNT_AUTH_IDENTITY identity;
106 SEC_WINNT_AUTH_IDENTITY *p_identity;
107 SecBuffer chlg_buf;
108 SecBuffer resp_buf;
109 SecBufferDesc chlg_desc;
110 SecBufferDesc resp_desc;
111 SECURITY_STATUS status;
112 unsigned long attrs;
113 TimeStamp expiry; /* For Windows 9x compatibility of SSPI calls */
114
115 /* Ensure we have a valid challenge message */
116 if(!Curl_bufref_len(chlg)) {
117 infof(data, "DIGEST-MD5 handshake failure (empty challenge message)");
118 return CURLE_BAD_CONTENT_ENCODING;
119 }
120
121 /* Query the security package for DigestSSP */
122 status = s_pSecFn->QuerySecurityPackageInfo((TCHAR *) TEXT(SP_NAME_DIGEST),
123 &SecurityPackage);
124 if(status != SEC_E_OK) {
125 failf(data, "SSPI: couldn't get auth info");
126 return CURLE_AUTH_ERROR;
127 }
128
129 token_max = SecurityPackage->cbMaxToken;
130
131 /* Release the package buffer as it is not required anymore */
132 s_pSecFn->FreeContextBuffer(SecurityPackage);
133
134 /* Allocate our response buffer */
135 output_token = malloc(token_max);
136 if(!output_token)
137 return CURLE_OUT_OF_MEMORY;
138
139 /* Generate our SPN */
140 spn = Curl_auth_build_spn(service, data->conn->host.name, NULL);
141 if(!spn) {
142 free(output_token);
143 return CURLE_OUT_OF_MEMORY;
144 }
145
146 if(userp && *userp) {
147 /* Populate our identity structure */
148 result = Curl_create_sspi_identity(userp, passwdp, &identity);
149 if(result) {
150 free(spn);
151 free(output_token);
152 return result;
153 }
154
155 /* Allow proper cleanup of the identity structure */
156 p_identity = &identity;
157 }
158 else
159 /* Use the current Windows user */
160 p_identity = NULL;
161
162 /* Acquire our credentials handle */
163 status = s_pSecFn->AcquireCredentialsHandle(NULL,
164 (TCHAR *) TEXT(SP_NAME_DIGEST),
165 SECPKG_CRED_OUTBOUND, NULL,
166 p_identity, NULL, NULL,
167 &credentials, &expiry);
168
169 if(status != SEC_E_OK) {
170 Curl_sspi_free_identity(p_identity);
171 free(spn);
172 free(output_token);
173 return CURLE_LOGIN_DENIED;
174 }
175
176 /* Setup the challenge "input" security buffer */
177 chlg_desc.ulVersion = SECBUFFER_VERSION;
178 chlg_desc.cBuffers = 1;
179 chlg_desc.pBuffers = &chlg_buf;
180 chlg_buf.BufferType = SECBUFFER_TOKEN;
181 chlg_buf.pvBuffer = (void *) Curl_bufref_ptr(chlg);
182 chlg_buf.cbBuffer = curlx_uztoul(Curl_bufref_len(chlg));
183
184 /* Setup the response "output" security buffer */
185 resp_desc.ulVersion = SECBUFFER_VERSION;
186 resp_desc.cBuffers = 1;
187 resp_desc.pBuffers = &resp_buf;
188 resp_buf.BufferType = SECBUFFER_TOKEN;
189 resp_buf.pvBuffer = output_token;
190 resp_buf.cbBuffer = curlx_uztoul(token_max);
191
192 /* Generate our response message */
193 status = s_pSecFn->InitializeSecurityContext(&credentials, NULL, spn,
194 0, 0, 0, &chlg_desc, 0,
195 &context, &resp_desc, &attrs,
196 &expiry);
197
198 if(status == SEC_I_COMPLETE_NEEDED ||
199 status == SEC_I_COMPLETE_AND_CONTINUE)
200 s_pSecFn->CompleteAuthToken(&credentials, &resp_desc);
201 else if(status != SEC_E_OK && status != SEC_I_CONTINUE_NEEDED) {
202 #if !defined(CURL_DISABLE_VERBOSE_STRINGS)
203 char buffer[STRERROR_LEN];
204 #endif
205
206 s_pSecFn->FreeCredentialsHandle(&credentials);
207 Curl_sspi_free_identity(p_identity);
208 free(spn);
209 free(output_token);
210
211 if(status == SEC_E_INSUFFICIENT_MEMORY)
212 return CURLE_OUT_OF_MEMORY;
213
214 #if !defined(CURL_DISABLE_VERBOSE_STRINGS)
215 infof(data, "schannel: InitializeSecurityContext failed: %s",
216 Curl_sspi_strerror(status, buffer, sizeof(buffer)));
217 #endif
218
219 return CURLE_AUTH_ERROR;
220 }
221
222 /* Return the response. */
223 Curl_bufref_set(out, output_token, resp_buf.cbBuffer, curl_free);
224
225 /* Free our handles */
226 s_pSecFn->DeleteSecurityContext(&context);
227 s_pSecFn->FreeCredentialsHandle(&credentials);
228
229 /* Free the identity structure */
230 Curl_sspi_free_identity(p_identity);
231
232 /* Free the SPN */
233 free(spn);
234
235 return result;
236 }
237
238 /*
239 * Curl_override_sspi_http_realm()
240 *
241 * This is used to populate the domain in a SSPI identity structure
242 * The realm is extracted from the challenge message and used as the
243 * domain if it is not already explicitly set.
244 *
245 * Parameters:
246 *
247 * chlg [in] - The challenge message.
248 * identity [in/out] - The identity structure.
249 *
250 * Returns CURLE_OK on success.
251 */
Curl_override_sspi_http_realm(const char * chlg,SEC_WINNT_AUTH_IDENTITY * identity)252 CURLcode Curl_override_sspi_http_realm(const char *chlg,
253 SEC_WINNT_AUTH_IDENTITY *identity)
254 {
255 xcharp_u domain, dup_domain;
256
257 /* If domain is blank or unset, check challenge message for realm */
258 if(!identity->Domain || !identity->DomainLength) {
259 for(;;) {
260 char value[DIGEST_MAX_VALUE_LENGTH];
261 char content[DIGEST_MAX_CONTENT_LENGTH];
262
263 /* Pass all additional spaces here */
264 while(*chlg && ISBLANK(*chlg))
265 chlg++;
266
267 /* Extract a value=content pair */
268 if(Curl_auth_digest_get_pair(chlg, value, content, &chlg)) {
269 if(strcasecompare(value, "realm")) {
270
271 /* Setup identity's domain and length */
272 domain.tchar_ptr = curlx_convert_UTF8_to_tchar((char *) content);
273 if(!domain.tchar_ptr)
274 return CURLE_OUT_OF_MEMORY;
275
276 dup_domain.tchar_ptr = _tcsdup(domain.tchar_ptr);
277 if(!dup_domain.tchar_ptr) {
278 curlx_unicodefree(domain.tchar_ptr);
279 return CURLE_OUT_OF_MEMORY;
280 }
281
282 free(identity->Domain);
283 identity->Domain = dup_domain.tbyte_ptr;
284 identity->DomainLength = curlx_uztoul(_tcslen(dup_domain.tchar_ptr));
285 dup_domain.tchar_ptr = NULL;
286
287 curlx_unicodefree(domain.tchar_ptr);
288 }
289 else {
290 /* Unknown specifier, ignore it! */
291 }
292 }
293 else
294 break; /* We're done here */
295
296 /* Pass all additional spaces here */
297 while(*chlg && ISBLANK(*chlg))
298 chlg++;
299
300 /* Allow the list to be comma-separated */
301 if(',' == *chlg)
302 chlg++;
303 }
304 }
305
306 return CURLE_OK;
307 }
308
309 /*
310 * Curl_auth_decode_digest_http_message()
311 *
312 * This is used to decode an HTTP DIGEST challenge message into the separate
313 * attributes.
314 *
315 * Parameters:
316 *
317 * chlg [in] - The challenge message.
318 * digest [in/out] - The digest data struct being used and modified.
319 *
320 * Returns CURLE_OK on success.
321 */
Curl_auth_decode_digest_http_message(const char * chlg,struct digestdata * digest)322 CURLcode Curl_auth_decode_digest_http_message(const char *chlg,
323 struct digestdata *digest)
324 {
325 size_t chlglen = strlen(chlg);
326
327 /* We had an input token before so if there's another one now that means we
328 provided bad credentials in the previous request or it's stale. */
329 if(digest->input_token) {
330 bool stale = false;
331 const char *p = chlg;
332
333 /* Check for the 'stale' directive */
334 for(;;) {
335 char value[DIGEST_MAX_VALUE_LENGTH];
336 char content[DIGEST_MAX_CONTENT_LENGTH];
337
338 while(*p && ISBLANK(*p))
339 p++;
340
341 if(!Curl_auth_digest_get_pair(p, value, content, &p))
342 break;
343
344 if(strcasecompare(value, "stale") &&
345 strcasecompare(content, "true")) {
346 stale = true;
347 break;
348 }
349
350 while(*p && ISBLANK(*p))
351 p++;
352
353 if(',' == *p)
354 p++;
355 }
356
357 if(stale)
358 Curl_auth_digest_cleanup(digest);
359 else
360 return CURLE_LOGIN_DENIED;
361 }
362
363 /* Store the challenge for use later */
364 digest->input_token = (BYTE *) Curl_memdup(chlg, chlglen + 1);
365 if(!digest->input_token)
366 return CURLE_OUT_OF_MEMORY;
367
368 digest->input_token_len = chlglen;
369
370 return CURLE_OK;
371 }
372
373 /*
374 * Curl_auth_create_digest_http_message()
375 *
376 * This is used to generate an HTTP DIGEST response message ready for sending
377 * to the recipient.
378 *
379 * Parameters:
380 *
381 * data [in] - The session handle.
382 * userp [in] - The user name in the format User or Domain\User.
383 * passwdp [in] - The user's password.
384 * request [in] - The HTTP request.
385 * uripath [in] - The path of the HTTP uri.
386 * digest [in/out] - The digest data struct being used and modified.
387 * outptr [in/out] - The address where a pointer to newly allocated memory
388 * holding the result will be stored upon completion.
389 * outlen [out] - The length of the output message.
390 *
391 * Returns CURLE_OK on success.
392 */
Curl_auth_create_digest_http_message(struct Curl_easy * data,const char * userp,const char * passwdp,const unsigned char * request,const unsigned char * uripath,struct digestdata * digest,char ** outptr,size_t * outlen)393 CURLcode Curl_auth_create_digest_http_message(struct Curl_easy *data,
394 const char *userp,
395 const char *passwdp,
396 const unsigned char *request,
397 const unsigned char *uripath,
398 struct digestdata *digest,
399 char **outptr, size_t *outlen)
400 {
401 size_t token_max;
402 char *resp;
403 BYTE *output_token;
404 size_t output_token_len = 0;
405 PSecPkgInfo SecurityPackage;
406 SecBuffer chlg_buf[5];
407 SecBufferDesc chlg_desc;
408 SECURITY_STATUS status;
409
410 (void) data;
411
412 /* Query the security package for DigestSSP */
413 status = s_pSecFn->QuerySecurityPackageInfo((TCHAR *) TEXT(SP_NAME_DIGEST),
414 &SecurityPackage);
415 if(status != SEC_E_OK) {
416 failf(data, "SSPI: couldn't get auth info");
417 return CURLE_AUTH_ERROR;
418 }
419
420 token_max = SecurityPackage->cbMaxToken;
421
422 /* Release the package buffer as it is not required anymore */
423 s_pSecFn->FreeContextBuffer(SecurityPackage);
424
425 /* Allocate the output buffer according to the max token size as indicated
426 by the security package */
427 output_token = malloc(token_max);
428 if(!output_token) {
429 return CURLE_OUT_OF_MEMORY;
430 }
431
432 /* If the user/passwd that was used to make the identity for http_context
433 has changed then delete that context. */
434 if((userp && !digest->user) || (!userp && digest->user) ||
435 (passwdp && !digest->passwd) || (!passwdp && digest->passwd) ||
436 (userp && digest->user && Curl_timestrcmp(userp, digest->user)) ||
437 (passwdp && digest->passwd && Curl_timestrcmp(passwdp, digest->passwd))) {
438 if(digest->http_context) {
439 s_pSecFn->DeleteSecurityContext(digest->http_context);
440 Curl_safefree(digest->http_context);
441 }
442 Curl_safefree(digest->user);
443 Curl_safefree(digest->passwd);
444 }
445
446 if(digest->http_context) {
447 chlg_desc.ulVersion = SECBUFFER_VERSION;
448 chlg_desc.cBuffers = 5;
449 chlg_desc.pBuffers = chlg_buf;
450 chlg_buf[0].BufferType = SECBUFFER_TOKEN;
451 chlg_buf[0].pvBuffer = NULL;
452 chlg_buf[0].cbBuffer = 0;
453 chlg_buf[1].BufferType = SECBUFFER_PKG_PARAMS;
454 chlg_buf[1].pvBuffer = (void *) request;
455 chlg_buf[1].cbBuffer = curlx_uztoul(strlen((const char *) request));
456 chlg_buf[2].BufferType = SECBUFFER_PKG_PARAMS;
457 chlg_buf[2].pvBuffer = (void *) uripath;
458 chlg_buf[2].cbBuffer = curlx_uztoul(strlen((const char *) uripath));
459 chlg_buf[3].BufferType = SECBUFFER_PKG_PARAMS;
460 chlg_buf[3].pvBuffer = NULL;
461 chlg_buf[3].cbBuffer = 0;
462 chlg_buf[4].BufferType = SECBUFFER_PADDING;
463 chlg_buf[4].pvBuffer = output_token;
464 chlg_buf[4].cbBuffer = curlx_uztoul(token_max);
465
466 status = s_pSecFn->MakeSignature(digest->http_context, 0, &chlg_desc, 0);
467 if(status == SEC_E_OK)
468 output_token_len = chlg_buf[4].cbBuffer;
469 else { /* delete the context so a new one can be made */
470 infof(data, "digest_sspi: MakeSignature failed, error 0x%08lx",
471 (long)status);
472 s_pSecFn->DeleteSecurityContext(digest->http_context);
473 Curl_safefree(digest->http_context);
474 }
475 }
476
477 if(!digest->http_context) {
478 CredHandle credentials;
479 SEC_WINNT_AUTH_IDENTITY identity;
480 SEC_WINNT_AUTH_IDENTITY *p_identity;
481 SecBuffer resp_buf;
482 SecBufferDesc resp_desc;
483 unsigned long attrs;
484 TimeStamp expiry; /* For Windows 9x compatibility of SSPI calls */
485 TCHAR *spn;
486
487 /* free the copy of user/passwd used to make the previous identity */
488 Curl_safefree(digest->user);
489 Curl_safefree(digest->passwd);
490
491 if(userp && *userp) {
492 /* Populate our identity structure */
493 if(Curl_create_sspi_identity(userp, passwdp, &identity)) {
494 free(output_token);
495 return CURLE_OUT_OF_MEMORY;
496 }
497
498 /* Populate our identity domain */
499 if(Curl_override_sspi_http_realm((const char *) digest->input_token,
500 &identity)) {
501 free(output_token);
502 return CURLE_OUT_OF_MEMORY;
503 }
504
505 /* Allow proper cleanup of the identity structure */
506 p_identity = &identity;
507 }
508 else
509 /* Use the current Windows user */
510 p_identity = NULL;
511
512 if(userp) {
513 digest->user = strdup(userp);
514
515 if(!digest->user) {
516 free(output_token);
517 return CURLE_OUT_OF_MEMORY;
518 }
519 }
520
521 if(passwdp) {
522 digest->passwd = strdup(passwdp);
523
524 if(!digest->passwd) {
525 free(output_token);
526 Curl_safefree(digest->user);
527 return CURLE_OUT_OF_MEMORY;
528 }
529 }
530
531 /* Acquire our credentials handle */
532 status = s_pSecFn->AcquireCredentialsHandle(NULL,
533 (TCHAR *) TEXT(SP_NAME_DIGEST),
534 SECPKG_CRED_OUTBOUND, NULL,
535 p_identity, NULL, NULL,
536 &credentials, &expiry);
537 if(status != SEC_E_OK) {
538 Curl_sspi_free_identity(p_identity);
539 free(output_token);
540
541 return CURLE_LOGIN_DENIED;
542 }
543
544 /* Setup the challenge "input" security buffer if present */
545 chlg_desc.ulVersion = SECBUFFER_VERSION;
546 chlg_desc.cBuffers = 3;
547 chlg_desc.pBuffers = chlg_buf;
548 chlg_buf[0].BufferType = SECBUFFER_TOKEN;
549 chlg_buf[0].pvBuffer = digest->input_token;
550 chlg_buf[0].cbBuffer = curlx_uztoul(digest->input_token_len);
551 chlg_buf[1].BufferType = SECBUFFER_PKG_PARAMS;
552 chlg_buf[1].pvBuffer = (void *) request;
553 chlg_buf[1].cbBuffer = curlx_uztoul(strlen((const char *) request));
554 chlg_buf[2].BufferType = SECBUFFER_PKG_PARAMS;
555 chlg_buf[2].pvBuffer = NULL;
556 chlg_buf[2].cbBuffer = 0;
557
558 /* Setup the response "output" security buffer */
559 resp_desc.ulVersion = SECBUFFER_VERSION;
560 resp_desc.cBuffers = 1;
561 resp_desc.pBuffers = &resp_buf;
562 resp_buf.BufferType = SECBUFFER_TOKEN;
563 resp_buf.pvBuffer = output_token;
564 resp_buf.cbBuffer = curlx_uztoul(token_max);
565
566 spn = curlx_convert_UTF8_to_tchar((char *) uripath);
567 if(!spn) {
568 s_pSecFn->FreeCredentialsHandle(&credentials);
569
570 Curl_sspi_free_identity(p_identity);
571 free(output_token);
572
573 return CURLE_OUT_OF_MEMORY;
574 }
575
576 /* Allocate our new context handle */
577 digest->http_context = calloc(1, sizeof(CtxtHandle));
578 if(!digest->http_context)
579 return CURLE_OUT_OF_MEMORY;
580
581 /* Generate our response message */
582 status = s_pSecFn->InitializeSecurityContext(&credentials, NULL,
583 spn,
584 ISC_REQ_USE_HTTP_STYLE, 0, 0,
585 &chlg_desc, 0,
586 digest->http_context,
587 &resp_desc, &attrs, &expiry);
588 curlx_unicodefree(spn);
589
590 if(status == SEC_I_COMPLETE_NEEDED ||
591 status == SEC_I_COMPLETE_AND_CONTINUE)
592 s_pSecFn->CompleteAuthToken(&credentials, &resp_desc);
593 else if(status != SEC_E_OK && status != SEC_I_CONTINUE_NEEDED) {
594 #if !defined(CURL_DISABLE_VERBOSE_STRINGS)
595 char buffer[STRERROR_LEN];
596 #endif
597
598 s_pSecFn->FreeCredentialsHandle(&credentials);
599
600 Curl_sspi_free_identity(p_identity);
601 free(output_token);
602
603 Curl_safefree(digest->http_context);
604
605 if(status == SEC_E_INSUFFICIENT_MEMORY)
606 return CURLE_OUT_OF_MEMORY;
607
608 #if !defined(CURL_DISABLE_VERBOSE_STRINGS)
609 infof(data, "schannel: InitializeSecurityContext failed: %s",
610 Curl_sspi_strerror(status, buffer, sizeof(buffer)));
611 #endif
612
613 return CURLE_AUTH_ERROR;
614 }
615
616 output_token_len = resp_buf.cbBuffer;
617
618 s_pSecFn->FreeCredentialsHandle(&credentials);
619 Curl_sspi_free_identity(p_identity);
620 }
621
622 resp = malloc(output_token_len + 1);
623 if(!resp) {
624 free(output_token);
625
626 return CURLE_OUT_OF_MEMORY;
627 }
628
629 /* Copy the generated response */
630 memcpy(resp, output_token, output_token_len);
631 resp[output_token_len] = 0;
632
633 /* Return the response */
634 *outptr = resp;
635 *outlen = output_token_len;
636
637 /* Free the response buffer */
638 free(output_token);
639
640 return CURLE_OK;
641 }
642
643 /*
644 * Curl_auth_digest_cleanup()
645 *
646 * This is used to clean up the digest specific data.
647 *
648 * Parameters:
649 *
650 * digest [in/out] - The digest data struct being cleaned up.
651 *
652 */
Curl_auth_digest_cleanup(struct digestdata * digest)653 void Curl_auth_digest_cleanup(struct digestdata *digest)
654 {
655 /* Free the input token */
656 Curl_safefree(digest->input_token);
657
658 /* Reset any variables */
659 digest->input_token_len = 0;
660
661 /* Delete security context */
662 if(digest->http_context) {
663 s_pSecFn->DeleteSecurityContext(digest->http_context);
664 Curl_safefree(digest->http_context);
665 }
666
667 /* Free the copy of user/passwd used to make the identity for http_context */
668 Curl_safefree(digest->user);
669 Curl_safefree(digest->passwd);
670 }
671
672 #endif /* USE_WINDOWS_SSPI && !CURL_DISABLE_DIGEST_AUTH */
673