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_CRYPTO_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 infof(data, "schannel: InitializeSecurityContext failed: %s",
215 Curl_sspi_strerror(status, buffer, sizeof(buffer)));
216
217 return CURLE_AUTH_ERROR;
218 }
219
220 /* Return the response. */
221 Curl_bufref_set(out, output_token, resp_buf.cbBuffer, curl_free);
222
223 /* Free our handles */
224 s_pSecFn->DeleteSecurityContext(&context);
225 s_pSecFn->FreeCredentialsHandle(&credentials);
226
227 /* Free the identity structure */
228 Curl_sspi_free_identity(p_identity);
229
230 /* Free the SPN */
231 free(spn);
232
233 return result;
234 }
235
236 /*
237 * Curl_override_sspi_http_realm()
238 *
239 * This is used to populate the domain in a SSPI identity structure
240 * The realm is extracted from the challenge message and used as the
241 * domain if it is not already explicitly set.
242 *
243 * Parameters:
244 *
245 * chlg [in] - The challenge message.
246 * identity [in/out] - The identity structure.
247 *
248 * Returns CURLE_OK on success.
249 */
Curl_override_sspi_http_realm(const char * chlg,SEC_WINNT_AUTH_IDENTITY * identity)250 CURLcode Curl_override_sspi_http_realm(const char *chlg,
251 SEC_WINNT_AUTH_IDENTITY *identity)
252 {
253 xcharp_u domain, dup_domain;
254
255 /* If domain is blank or unset, check challenge message for realm */
256 if(!identity->Domain || !identity->DomainLength) {
257 for(;;) {
258 char value[DIGEST_MAX_VALUE_LENGTH];
259 char content[DIGEST_MAX_CONTENT_LENGTH];
260
261 /* Pass all additional spaces here */
262 while(*chlg && ISBLANK(*chlg))
263 chlg++;
264
265 /* Extract a value=content pair */
266 if(Curl_auth_digest_get_pair(chlg, value, content, &chlg)) {
267 if(strcasecompare(value, "realm")) {
268
269 /* Setup identity's domain and length */
270 domain.tchar_ptr = curlx_convert_UTF8_to_tchar((char *) content);
271 if(!domain.tchar_ptr)
272 return CURLE_OUT_OF_MEMORY;
273
274 dup_domain.tchar_ptr = _tcsdup(domain.tchar_ptr);
275 if(!dup_domain.tchar_ptr) {
276 curlx_unicodefree(domain.tchar_ptr);
277 return CURLE_OUT_OF_MEMORY;
278 }
279
280 free(identity->Domain);
281 identity->Domain = dup_domain.tbyte_ptr;
282 identity->DomainLength = curlx_uztoul(_tcslen(dup_domain.tchar_ptr));
283 dup_domain.tchar_ptr = NULL;
284
285 curlx_unicodefree(domain.tchar_ptr);
286 }
287 else {
288 /* Unknown specifier, ignore it! */
289 }
290 }
291 else
292 break; /* We're done here */
293
294 /* Pass all additional spaces here */
295 while(*chlg && ISBLANK(*chlg))
296 chlg++;
297
298 /* Allow the list to be comma-separated */
299 if(',' == *chlg)
300 chlg++;
301 }
302 }
303
304 return CURLE_OK;
305 }
306
307 /*
308 * Curl_auth_decode_digest_http_message()
309 *
310 * This is used to decode an HTTP DIGEST challenge message into the separate
311 * attributes.
312 *
313 * Parameters:
314 *
315 * chlg [in] - The challenge message.
316 * digest [in/out] - The digest data struct being used and modified.
317 *
318 * Returns CURLE_OK on success.
319 */
Curl_auth_decode_digest_http_message(const char * chlg,struct digestdata * digest)320 CURLcode Curl_auth_decode_digest_http_message(const char *chlg,
321 struct digestdata *digest)
322 {
323 size_t chlglen = strlen(chlg);
324
325 /* We had an input token before so if there's another one now that means we
326 provided bad credentials in the previous request or it's stale. */
327 if(digest->input_token) {
328 bool stale = false;
329 const char *p = chlg;
330
331 /* Check for the 'stale' directive */
332 for(;;) {
333 char value[DIGEST_MAX_VALUE_LENGTH];
334 char content[DIGEST_MAX_CONTENT_LENGTH];
335
336 while(*p && ISBLANK(*p))
337 p++;
338
339 if(!Curl_auth_digest_get_pair(p, value, content, &p))
340 break;
341
342 if(strcasecompare(value, "stale") &&
343 strcasecompare(content, "true")) {
344 stale = true;
345 break;
346 }
347
348 while(*p && ISBLANK(*p))
349 p++;
350
351 if(',' == *p)
352 p++;
353 }
354
355 if(stale)
356 Curl_auth_digest_cleanup(digest);
357 else
358 return CURLE_LOGIN_DENIED;
359 }
360
361 /* Store the challenge for use later */
362 digest->input_token = (BYTE *) Curl_memdup(chlg, chlglen + 1);
363 if(!digest->input_token)
364 return CURLE_OUT_OF_MEMORY;
365
366 digest->input_token_len = chlglen;
367
368 return CURLE_OK;
369 }
370
371 /*
372 * Curl_auth_create_digest_http_message()
373 *
374 * This is used to generate an HTTP DIGEST response message ready for sending
375 * to the recipient.
376 *
377 * Parameters:
378 *
379 * data [in] - The session handle.
380 * userp [in] - The user name in the format User or Domain\User.
381 * passwdp [in] - The user's password.
382 * request [in] - The HTTP request.
383 * uripath [in] - The path of the HTTP uri.
384 * digest [in/out] - The digest data struct being used and modified.
385 * outptr [in/out] - The address where a pointer to newly allocated memory
386 * holding the result will be stored upon completion.
387 * outlen [out] - The length of the output message.
388 *
389 * Returns CURLE_OK on success.
390 */
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)391 CURLcode Curl_auth_create_digest_http_message(struct Curl_easy *data,
392 const char *userp,
393 const char *passwdp,
394 const unsigned char *request,
395 const unsigned char *uripath,
396 struct digestdata *digest,
397 char **outptr, size_t *outlen)
398 {
399 size_t token_max;
400 char *resp;
401 BYTE *output_token;
402 size_t output_token_len = 0;
403 PSecPkgInfo SecurityPackage;
404 SecBuffer chlg_buf[5];
405 SecBufferDesc chlg_desc;
406 SECURITY_STATUS status;
407
408 (void) data;
409
410 /* Query the security package for DigestSSP */
411 status = s_pSecFn->QuerySecurityPackageInfo((TCHAR *) TEXT(SP_NAME_DIGEST),
412 &SecurityPackage);
413 if(status != SEC_E_OK) {
414 failf(data, "SSPI: couldn't get auth info");
415 return CURLE_AUTH_ERROR;
416 }
417
418 token_max = SecurityPackage->cbMaxToken;
419
420 /* Release the package buffer as it is not required anymore */
421 s_pSecFn->FreeContextBuffer(SecurityPackage);
422
423 /* Allocate the output buffer according to the max token size as indicated
424 by the security package */
425 output_token = malloc(token_max);
426 if(!output_token) {
427 return CURLE_OUT_OF_MEMORY;
428 }
429
430 /* If the user/passwd that was used to make the identity for http_context
431 has changed then delete that context. */
432 if((userp && !digest->user) || (!userp && digest->user) ||
433 (passwdp && !digest->passwd) || (!passwdp && digest->passwd) ||
434 (userp && digest->user && Curl_timestrcmp(userp, digest->user)) ||
435 (passwdp && digest->passwd && Curl_timestrcmp(passwdp, digest->passwd))) {
436 if(digest->http_context) {
437 s_pSecFn->DeleteSecurityContext(digest->http_context);
438 Curl_safefree(digest->http_context);
439 }
440 Curl_safefree(digest->user);
441 Curl_safefree(digest->passwd);
442 }
443
444 if(digest->http_context) {
445 chlg_desc.ulVersion = SECBUFFER_VERSION;
446 chlg_desc.cBuffers = 5;
447 chlg_desc.pBuffers = chlg_buf;
448 chlg_buf[0].BufferType = SECBUFFER_TOKEN;
449 chlg_buf[0].pvBuffer = NULL;
450 chlg_buf[0].cbBuffer = 0;
451 chlg_buf[1].BufferType = SECBUFFER_PKG_PARAMS;
452 chlg_buf[1].pvBuffer = (void *) request;
453 chlg_buf[1].cbBuffer = curlx_uztoul(strlen((const char *) request));
454 chlg_buf[2].BufferType = SECBUFFER_PKG_PARAMS;
455 chlg_buf[2].pvBuffer = (void *) uripath;
456 chlg_buf[2].cbBuffer = curlx_uztoul(strlen((const char *) uripath));
457 chlg_buf[3].BufferType = SECBUFFER_PKG_PARAMS;
458 chlg_buf[3].pvBuffer = NULL;
459 chlg_buf[3].cbBuffer = 0;
460 chlg_buf[4].BufferType = SECBUFFER_PADDING;
461 chlg_buf[4].pvBuffer = output_token;
462 chlg_buf[4].cbBuffer = curlx_uztoul(token_max);
463
464 status = s_pSecFn->MakeSignature(digest->http_context, 0, &chlg_desc, 0);
465 if(status == SEC_E_OK)
466 output_token_len = chlg_buf[4].cbBuffer;
467 else { /* delete the context so a new one can be made */
468 infof(data, "digest_sspi: MakeSignature failed, error 0x%08lx",
469 (long)status);
470 s_pSecFn->DeleteSecurityContext(digest->http_context);
471 Curl_safefree(digest->http_context);
472 }
473 }
474
475 if(!digest->http_context) {
476 CredHandle credentials;
477 SEC_WINNT_AUTH_IDENTITY identity;
478 SEC_WINNT_AUTH_IDENTITY *p_identity;
479 SecBuffer resp_buf;
480 SecBufferDesc resp_desc;
481 unsigned long attrs;
482 TimeStamp expiry; /* For Windows 9x compatibility of SSPI calls */
483 TCHAR *spn;
484
485 /* free the copy of user/passwd used to make the previous identity */
486 Curl_safefree(digest->user);
487 Curl_safefree(digest->passwd);
488
489 if(userp && *userp) {
490 /* Populate our identity structure */
491 if(Curl_create_sspi_identity(userp, passwdp, &identity)) {
492 free(output_token);
493 return CURLE_OUT_OF_MEMORY;
494 }
495
496 /* Populate our identity domain */
497 if(Curl_override_sspi_http_realm((const char *) digest->input_token,
498 &identity)) {
499 free(output_token);
500 return CURLE_OUT_OF_MEMORY;
501 }
502
503 /* Allow proper cleanup of the identity structure */
504 p_identity = &identity;
505 }
506 else
507 /* Use the current Windows user */
508 p_identity = NULL;
509
510 if(userp) {
511 digest->user = strdup(userp);
512
513 if(!digest->user) {
514 free(output_token);
515 return CURLE_OUT_OF_MEMORY;
516 }
517 }
518
519 if(passwdp) {
520 digest->passwd = strdup(passwdp);
521
522 if(!digest->passwd) {
523 free(output_token);
524 Curl_safefree(digest->user);
525 return CURLE_OUT_OF_MEMORY;
526 }
527 }
528
529 /* Acquire our credentials handle */
530 status = s_pSecFn->AcquireCredentialsHandle(NULL,
531 (TCHAR *) TEXT(SP_NAME_DIGEST),
532 SECPKG_CRED_OUTBOUND, NULL,
533 p_identity, NULL, NULL,
534 &credentials, &expiry);
535 if(status != SEC_E_OK) {
536 Curl_sspi_free_identity(p_identity);
537 free(output_token);
538
539 return CURLE_LOGIN_DENIED;
540 }
541
542 /* Setup the challenge "input" security buffer if present */
543 chlg_desc.ulVersion = SECBUFFER_VERSION;
544 chlg_desc.cBuffers = 3;
545 chlg_desc.pBuffers = chlg_buf;
546 chlg_buf[0].BufferType = SECBUFFER_TOKEN;
547 chlg_buf[0].pvBuffer = digest->input_token;
548 chlg_buf[0].cbBuffer = curlx_uztoul(digest->input_token_len);
549 chlg_buf[1].BufferType = SECBUFFER_PKG_PARAMS;
550 chlg_buf[1].pvBuffer = (void *) request;
551 chlg_buf[1].cbBuffer = curlx_uztoul(strlen((const char *) request));
552 chlg_buf[2].BufferType = SECBUFFER_PKG_PARAMS;
553 chlg_buf[2].pvBuffer = NULL;
554 chlg_buf[2].cbBuffer = 0;
555
556 /* Setup the response "output" security buffer */
557 resp_desc.ulVersion = SECBUFFER_VERSION;
558 resp_desc.cBuffers = 1;
559 resp_desc.pBuffers = &resp_buf;
560 resp_buf.BufferType = SECBUFFER_TOKEN;
561 resp_buf.pvBuffer = output_token;
562 resp_buf.cbBuffer = curlx_uztoul(token_max);
563
564 spn = curlx_convert_UTF8_to_tchar((char *) uripath);
565 if(!spn) {
566 s_pSecFn->FreeCredentialsHandle(&credentials);
567
568 Curl_sspi_free_identity(p_identity);
569 free(output_token);
570
571 return CURLE_OUT_OF_MEMORY;
572 }
573
574 /* Allocate our new context handle */
575 digest->http_context = calloc(1, sizeof(CtxtHandle));
576 if(!digest->http_context)
577 return CURLE_OUT_OF_MEMORY;
578
579 /* Generate our response message */
580 status = s_pSecFn->InitializeSecurityContext(&credentials, NULL,
581 spn,
582 ISC_REQ_USE_HTTP_STYLE, 0, 0,
583 &chlg_desc, 0,
584 digest->http_context,
585 &resp_desc, &attrs, &expiry);
586 curlx_unicodefree(spn);
587
588 if(status == SEC_I_COMPLETE_NEEDED ||
589 status == SEC_I_COMPLETE_AND_CONTINUE)
590 s_pSecFn->CompleteAuthToken(&credentials, &resp_desc);
591 else if(status != SEC_E_OK && status != SEC_I_CONTINUE_NEEDED) {
592 #if !defined(CURL_DISABLE_VERBOSE_STRINGS)
593 char buffer[STRERROR_LEN];
594 #endif
595
596 s_pSecFn->FreeCredentialsHandle(&credentials);
597
598 Curl_sspi_free_identity(p_identity);
599 free(output_token);
600
601 Curl_safefree(digest->http_context);
602
603 if(status == SEC_E_INSUFFICIENT_MEMORY)
604 return CURLE_OUT_OF_MEMORY;
605
606 infof(data, "schannel: InitializeSecurityContext failed: %s",
607 Curl_sspi_strerror(status, buffer, sizeof(buffer)));
608
609 return CURLE_AUTH_ERROR;
610 }
611
612 output_token_len = resp_buf.cbBuffer;
613
614 s_pSecFn->FreeCredentialsHandle(&credentials);
615 Curl_sspi_free_identity(p_identity);
616 }
617
618 resp = malloc(output_token_len + 1);
619 if(!resp) {
620 free(output_token);
621
622 return CURLE_OUT_OF_MEMORY;
623 }
624
625 /* Copy the generated response */
626 memcpy(resp, output_token, output_token_len);
627 resp[output_token_len] = 0;
628
629 /* Return the response */
630 *outptr = resp;
631 *outlen = output_token_len;
632
633 /* Free the response buffer */
634 free(output_token);
635
636 return CURLE_OK;
637 }
638
639 /*
640 * Curl_auth_digest_cleanup()
641 *
642 * This is used to clean up the digest specific data.
643 *
644 * Parameters:
645 *
646 * digest [in/out] - The digest data struct being cleaned up.
647 *
648 */
Curl_auth_digest_cleanup(struct digestdata * digest)649 void Curl_auth_digest_cleanup(struct digestdata *digest)
650 {
651 /* Free the input token */
652 Curl_safefree(digest->input_token);
653
654 /* Reset any variables */
655 digest->input_token_len = 0;
656
657 /* Delete security context */
658 if(digest->http_context) {
659 s_pSecFn->DeleteSecurityContext(digest->http_context);
660 Curl_safefree(digest->http_context);
661 }
662
663 /* Free the copy of user/passwd used to make the identity for http_context */
664 Curl_safefree(digest->user);
665 Curl_safefree(digest->passwd);
666 }
667
668 #endif /* USE_WINDOWS_SSPI && !CURL_DISABLE_CRYPTO_AUTH */
669