1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 2012 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at https://curl.haxx.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 * RFC2195 CRAM-MD5 authentication
22 * RFC2617 Basic and Digest Access Authentication
23 * RFC2831 DIGEST-MD5 authentication
24 * RFC4422 Simple Authentication and Security Layer (SASL)
25 * RFC4616 PLAIN authentication
26 * RFC6749 OAuth 2.0 Authorization Framework
27 * RFC7628 A Set of SASL Mechanisms for OAuth
28 * Draft LOGIN SASL Mechanism <draft-murchison-sasl-login-00.txt>
29 *
30 ***************************************************************************/
31
32 #include "curl_setup.h"
33
34 #include <curl/curl.h>
35 #include "urldata.h"
36
37 #include "curl_base64.h"
38 #include "curl_md5.h"
39 #include "vauth/vauth.h"
40 #include "vtls/vtls.h"
41 #include "curl_hmac.h"
42 #include "curl_sasl.h"
43 #include "warnless.h"
44 #include "strtok.h"
45 #include "sendf.h"
46 #include "non-ascii.h" /* included for Curl_convert_... prototypes */
47 /* The last 3 #include files should be in this order */
48 #include "curl_printf.h"
49 #include "curl_memory.h"
50 #include "memdebug.h"
51
52 /* Supported mechanisms */
53 const struct {
54 const char *name; /* Name */
55 size_t len; /* Name length */
56 unsigned int bit; /* Flag bit */
57 } mechtable[] = {
58 { "LOGIN", 5, SASL_MECH_LOGIN },
59 { "PLAIN", 5, SASL_MECH_PLAIN },
60 { "CRAM-MD5", 8, SASL_MECH_CRAM_MD5 },
61 { "DIGEST-MD5", 10, SASL_MECH_DIGEST_MD5 },
62 { "GSSAPI", 6, SASL_MECH_GSSAPI },
63 { "EXTERNAL", 8, SASL_MECH_EXTERNAL },
64 { "NTLM", 4, SASL_MECH_NTLM },
65 { "XOAUTH2", 7, SASL_MECH_XOAUTH2 },
66 { "OAUTHBEARER", 11, SASL_MECH_OAUTHBEARER },
67 { ZERO_NULL, 0, 0 }
68 };
69
70 /*
71 * Curl_sasl_cleanup()
72 *
73 * This is used to cleanup any libraries or curl modules used by the sasl
74 * functions.
75 *
76 * Parameters:
77 *
78 * conn [in] - The connection data.
79 * authused [in] - The authentication mechanism used.
80 */
Curl_sasl_cleanup(struct connectdata * conn,unsigned int authused)81 void Curl_sasl_cleanup(struct connectdata *conn, unsigned int authused)
82 {
83 #if defined(USE_KERBEROS5)
84 /* Cleanup the gssapi structure */
85 if(authused == SASL_MECH_GSSAPI) {
86 Curl_auth_gssapi_cleanup(&conn->krb5);
87 }
88 #endif
89
90 #if defined(USE_NTLM)
91 /* Cleanup the NTLM structure */
92 if(authused == SASL_MECH_NTLM) {
93 Curl_auth_ntlm_cleanup(&conn->ntlm);
94 }
95 #endif
96
97 #if !defined(USE_KERBEROS5) && !defined(USE_NTLM)
98 /* Reserved for future use */
99 (void)conn;
100 (void)authused;
101 #endif
102 }
103
104 /*
105 * Curl_sasl_decode_mech()
106 *
107 * Convert a SASL mechanism name into a token.
108 *
109 * Parameters:
110 *
111 * ptr [in] - The mechanism string.
112 * maxlen [in] - Maximum mechanism string length.
113 * len [out] - If not NULL, effective name length.
114 *
115 * Returns the SASL mechanism token or 0 if no match.
116 */
Curl_sasl_decode_mech(const char * ptr,size_t maxlen,size_t * len)117 unsigned int Curl_sasl_decode_mech(const char *ptr, size_t maxlen, size_t *len)
118 {
119 unsigned int i;
120 char c;
121
122 for(i = 0; mechtable[i].name; i++) {
123 if(maxlen >= mechtable[i].len &&
124 !memcmp(ptr, mechtable[i].name, mechtable[i].len)) {
125 if(len)
126 *len = mechtable[i].len;
127
128 if(maxlen == mechtable[i].len)
129 return mechtable[i].bit;
130
131 c = ptr[mechtable[i].len];
132 if(!ISUPPER(c) && !ISDIGIT(c) && c != '-' && c != '_')
133 return mechtable[i].bit;
134 }
135 }
136
137 return 0;
138 }
139
140 /*
141 * Curl_sasl_parse_url_auth_option()
142 *
143 * Parse the URL login options.
144 */
Curl_sasl_parse_url_auth_option(struct SASL * sasl,const char * value,size_t len)145 CURLcode Curl_sasl_parse_url_auth_option(struct SASL *sasl,
146 const char *value, size_t len)
147 {
148 CURLcode result = CURLE_OK;
149 unsigned int mechbit;
150 size_t mechlen;
151
152 if(!len)
153 return CURLE_URL_MALFORMAT;
154
155 if(sasl->resetprefs) {
156 sasl->resetprefs = FALSE;
157 sasl->prefmech = SASL_AUTH_NONE;
158 }
159
160 if(!strncmp(value, "*", len))
161 sasl->prefmech = SASL_AUTH_DEFAULT;
162 else {
163 mechbit = Curl_sasl_decode_mech(value, len, &mechlen);
164 if(mechbit && mechlen == len)
165 sasl->prefmech |= mechbit;
166 else
167 result = CURLE_URL_MALFORMAT;
168 }
169
170 return result;
171 }
172
173 /*
174 * Curl_sasl_init()
175 *
176 * Initializes the SASL structure.
177 */
Curl_sasl_init(struct SASL * sasl,const struct SASLproto * params)178 void Curl_sasl_init(struct SASL *sasl, const struct SASLproto *params)
179 {
180 sasl->params = params; /* Set protocol dependent parameters */
181 sasl->state = SASL_STOP; /* Not yet running */
182 sasl->authmechs = SASL_AUTH_NONE; /* No known authentication mechanism yet */
183 sasl->prefmech = SASL_AUTH_DEFAULT; /* Prefer all mechanisms */
184 sasl->authused = SASL_AUTH_NONE; /* No the authentication mechanism used */
185 sasl->resetprefs = TRUE; /* Reset prefmech upon AUTH parsing. */
186 sasl->mutual_auth = FALSE; /* No mutual authentication (GSSAPI only) */
187 sasl->force_ir = FALSE; /* Respect external option */
188 }
189
190 /*
191 * state()
192 *
193 * This is the ONLY way to change SASL state!
194 */
state(struct SASL * sasl,struct connectdata * conn,saslstate newstate)195 static void state(struct SASL *sasl, struct connectdata *conn,
196 saslstate newstate)
197 {
198 #if defined(DEBUGBUILD) && !defined(CURL_DISABLE_VERBOSE_STRINGS)
199 /* for debug purposes */
200 static const char * const names[]={
201 "STOP",
202 "PLAIN",
203 "LOGIN",
204 "LOGIN_PASSWD",
205 "EXTERNAL",
206 "CRAMMD5",
207 "DIGESTMD5",
208 "DIGESTMD5_RESP",
209 "NTLM",
210 "NTLM_TYPE2MSG",
211 "GSSAPI",
212 "GSSAPI_TOKEN",
213 "GSSAPI_NO_DATA",
214 "OAUTH2",
215 "OAUTH2_RESP",
216 "CANCEL",
217 "FINAL",
218 /* LAST */
219 };
220
221 if(sasl->state != newstate)
222 infof(conn->data, "SASL %p state change from %s to %s\n",
223 (void *)sasl, names[sasl->state], names[newstate]);
224 #else
225 (void) conn;
226 #endif
227
228 sasl->state = newstate;
229 }
230
231 /*
232 * Curl_sasl_can_authenticate()
233 *
234 * Check if we have enough auth data and capabilities to authenticate.
235 */
Curl_sasl_can_authenticate(struct SASL * sasl,struct connectdata * conn)236 bool Curl_sasl_can_authenticate(struct SASL *sasl, struct connectdata *conn)
237 {
238 /* Have credentials been provided? */
239 if(conn->bits.user_passwd)
240 return TRUE;
241
242 /* EXTERNAL can authenticate without a user name and/or password */
243 if(sasl->authmechs & sasl->prefmech & SASL_MECH_EXTERNAL)
244 return TRUE;
245
246 return FALSE;
247 }
248
249 /*
250 * Curl_sasl_start()
251 *
252 * Calculate the required login details for SASL authentication.
253 */
Curl_sasl_start(struct SASL * sasl,struct connectdata * conn,bool force_ir,saslprogress * progress)254 CURLcode Curl_sasl_start(struct SASL *sasl, struct connectdata *conn,
255 bool force_ir, saslprogress *progress)
256 {
257 CURLcode result = CURLE_OK;
258 struct Curl_easy *data = conn->data;
259 unsigned int enabledmechs;
260 const char *mech = NULL;
261 char *resp = NULL;
262 size_t len = 0;
263 saslstate state1 = SASL_STOP;
264 saslstate state2 = SASL_FINAL;
265 const char * const hostname = SSL_IS_PROXY() ? conn->http_proxy.host.name :
266 conn->host.name;
267 const long int port = SSL_IS_PROXY() ? conn->port : conn->remote_port;
268 #if defined(USE_KERBEROS5)
269 const char *service = data->set.str[STRING_SERVICE_NAME] ?
270 data->set.str[STRING_SERVICE_NAME] :
271 sasl->params->service;
272 #endif
273
274 sasl->force_ir = force_ir; /* Latch for future use */
275 sasl->authused = 0; /* No mechanism used yet */
276 enabledmechs = sasl->authmechs & sasl->prefmech;
277 *progress = SASL_IDLE;
278
279 /* Calculate the supported authentication mechanism, by decreasing order of
280 security, as well as the initial response where appropriate */
281 if((enabledmechs & SASL_MECH_EXTERNAL) && !conn->passwd[0]) {
282 mech = SASL_MECH_STRING_EXTERNAL;
283 state1 = SASL_EXTERNAL;
284 sasl->authused = SASL_MECH_EXTERNAL;
285
286 if(force_ir || data->set.sasl_ir)
287 result = Curl_auth_create_external_message(data, conn->user, &resp,
288 &len);
289 }
290 else if(conn->bits.user_passwd) {
291 #if defined(USE_KERBEROS5)
292 if((enabledmechs & SASL_MECH_GSSAPI) && Curl_auth_is_gssapi_supported() &&
293 Curl_auth_user_contains_domain(conn->user)) {
294 sasl->mutual_auth = FALSE; /* TODO: Calculate mutual authentication */
295 mech = SASL_MECH_STRING_GSSAPI;
296 state1 = SASL_GSSAPI;
297 state2 = SASL_GSSAPI_TOKEN;
298 sasl->authused = SASL_MECH_GSSAPI;
299
300 if(force_ir || data->set.sasl_ir)
301 result = Curl_auth_create_gssapi_user_message(data, conn->user,
302 conn->passwd,
303 service,
304 data->easy_conn->
305 host.name,
306 sasl->mutual_auth,
307 NULL, &conn->krb5,
308 &resp, &len);
309 }
310 else
311 #endif
312 #ifndef CURL_DISABLE_CRYPTO_AUTH
313 if((enabledmechs & SASL_MECH_DIGEST_MD5) &&
314 Curl_auth_is_digest_supported()) {
315 mech = SASL_MECH_STRING_DIGEST_MD5;
316 state1 = SASL_DIGESTMD5;
317 sasl->authused = SASL_MECH_DIGEST_MD5;
318 }
319 else if(enabledmechs & SASL_MECH_CRAM_MD5) {
320 mech = SASL_MECH_STRING_CRAM_MD5;
321 state1 = SASL_CRAMMD5;
322 sasl->authused = SASL_MECH_CRAM_MD5;
323 }
324 else
325 #endif
326 #ifdef USE_NTLM
327 if((enabledmechs & SASL_MECH_NTLM) && Curl_auth_is_ntlm_supported()) {
328 mech = SASL_MECH_STRING_NTLM;
329 state1 = SASL_NTLM;
330 state2 = SASL_NTLM_TYPE2MSG;
331 sasl->authused = SASL_MECH_NTLM;
332
333 if(force_ir || data->set.sasl_ir)
334 result = Curl_auth_create_ntlm_type1_message(conn->user, conn->passwd,
335 &conn->ntlm, &resp, &len);
336 }
337 else
338 #endif
339 if((enabledmechs & SASL_MECH_OAUTHBEARER) && conn->oauth_bearer) {
340 mech = SASL_MECH_STRING_OAUTHBEARER;
341 state1 = SASL_OAUTH2;
342 state2 = SASL_OAUTH2_RESP;
343 sasl->authused = SASL_MECH_OAUTHBEARER;
344
345 if(force_ir || data->set.sasl_ir)
346 result = Curl_auth_create_oauth_bearer_message(data, conn->user,
347 hostname,
348 port,
349 conn->oauth_bearer,
350 &resp, &len);
351 }
352 else if((enabledmechs & SASL_MECH_XOAUTH2) && conn->oauth_bearer) {
353 mech = SASL_MECH_STRING_XOAUTH2;
354 state1 = SASL_OAUTH2;
355 sasl->authused = SASL_MECH_XOAUTH2;
356
357 if(force_ir || data->set.sasl_ir)
358 result = Curl_auth_create_oauth_bearer_message(data, conn->user,
359 NULL, 0,
360 conn->oauth_bearer,
361 &resp, &len);
362 }
363 else if(enabledmechs & SASL_MECH_LOGIN) {
364 mech = SASL_MECH_STRING_LOGIN;
365 state1 = SASL_LOGIN;
366 state2 = SASL_LOGIN_PASSWD;
367 sasl->authused = SASL_MECH_LOGIN;
368
369 if(force_ir || data->set.sasl_ir)
370 result = Curl_auth_create_login_message(data, conn->user, &resp, &len);
371 }
372 else if(enabledmechs & SASL_MECH_PLAIN) {
373 mech = SASL_MECH_STRING_PLAIN;
374 state1 = SASL_PLAIN;
375 sasl->authused = SASL_MECH_PLAIN;
376
377 if(force_ir || data->set.sasl_ir)
378 result = Curl_auth_create_plain_message(data, conn->user, conn->passwd,
379 &resp, &len);
380 }
381 }
382
383 if(!result && mech) {
384 if(resp && sasl->params->maxirlen &&
385 strlen(mech) + len > sasl->params->maxirlen) {
386 free(resp);
387 resp = NULL;
388 }
389
390 result = sasl->params->sendauth(conn, mech, resp);
391 if(!result) {
392 *progress = SASL_INPROGRESS;
393 state(sasl, conn, resp ? state2 : state1);
394 }
395 }
396
397 free(resp);
398
399 return result;
400 }
401
402 /*
403 * Curl_sasl_continue()
404 *
405 * Continue the authentication.
406 */
Curl_sasl_continue(struct SASL * sasl,struct connectdata * conn,int code,saslprogress * progress)407 CURLcode Curl_sasl_continue(struct SASL *sasl, struct connectdata *conn,
408 int code, saslprogress *progress)
409 {
410 CURLcode result = CURLE_OK;
411 struct Curl_easy *data = conn->data;
412 saslstate newstate = SASL_FINAL;
413 char *resp = NULL;
414 const char * const hostname = SSL_IS_PROXY() ? conn->http_proxy.host.name :
415 conn->host.name;
416 const long int port = SSL_IS_PROXY() ? conn->port : conn->remote_port;
417 #if !defined(CURL_DISABLE_CRYPTO_AUTH)
418 char *serverdata;
419 char *chlg = NULL;
420 size_t chlglen = 0;
421 #endif
422 #if !defined(CURL_DISABLE_CRYPTO_AUTH) || defined(USE_KERBEROS5)
423 const char *service = data->set.str[STRING_SERVICE_NAME] ?
424 data->set.str[STRING_SERVICE_NAME] :
425 sasl->params->service;
426 #endif
427 size_t len = 0;
428
429 *progress = SASL_INPROGRESS;
430
431 if(sasl->state == SASL_FINAL) {
432 if(code != sasl->params->finalcode)
433 result = CURLE_LOGIN_DENIED;
434 *progress = SASL_DONE;
435 state(sasl, conn, SASL_STOP);
436 return result;
437 }
438
439 if(sasl->state != SASL_CANCEL && sasl->state != SASL_OAUTH2_RESP &&
440 code != sasl->params->contcode) {
441 *progress = SASL_DONE;
442 state(sasl, conn, SASL_STOP);
443 return CURLE_LOGIN_DENIED;
444 }
445
446 switch(sasl->state) {
447 case SASL_STOP:
448 *progress = SASL_DONE;
449 return result;
450 case SASL_PLAIN:
451 result = Curl_auth_create_plain_message(data, conn->user, conn->passwd,
452 &resp,
453 &len);
454 break;
455 case SASL_LOGIN:
456 result = Curl_auth_create_login_message(data, conn->user, &resp, &len);
457 newstate = SASL_LOGIN_PASSWD;
458 break;
459 case SASL_LOGIN_PASSWD:
460 result = Curl_auth_create_login_message(data, conn->passwd, &resp, &len);
461 break;
462 case SASL_EXTERNAL:
463 result = Curl_auth_create_external_message(data, conn->user, &resp, &len);
464 break;
465
466 #ifndef CURL_DISABLE_CRYPTO_AUTH
467 case SASL_CRAMMD5:
468 sasl->params->getmessage(data->state.buffer, &serverdata);
469 result = Curl_auth_decode_cram_md5_message(serverdata, &chlg, &chlglen);
470 if(!result)
471 result = Curl_auth_create_cram_md5_message(data, chlg, conn->user,
472 conn->passwd, &resp, &len);
473 free(chlg);
474 break;
475 case SASL_DIGESTMD5:
476 sasl->params->getmessage(data->state.buffer, &serverdata);
477 result = Curl_auth_create_digest_md5_message(data, serverdata,
478 conn->user, conn->passwd,
479 service,
480 &resp, &len);
481 newstate = SASL_DIGESTMD5_RESP;
482 break;
483 case SASL_DIGESTMD5_RESP:
484 resp = strdup("");
485 if(!resp)
486 result = CURLE_OUT_OF_MEMORY;
487 break;
488 #endif
489
490 #ifdef USE_NTLM
491 case SASL_NTLM:
492 /* Create the type-1 message */
493 result = Curl_auth_create_ntlm_type1_message(conn->user, conn->passwd,
494 &conn->ntlm, &resp, &len);
495 newstate = SASL_NTLM_TYPE2MSG;
496 break;
497 case SASL_NTLM_TYPE2MSG:
498 /* Decode the type-2 message */
499 sasl->params->getmessage(data->state.buffer, &serverdata);
500 result = Curl_auth_decode_ntlm_type2_message(data, serverdata,
501 &conn->ntlm);
502 if(!result)
503 result = Curl_auth_create_ntlm_type3_message(data, conn->user,
504 conn->passwd, &conn->ntlm,
505 &resp, &len);
506 break;
507 #endif
508
509 #if defined(USE_KERBEROS5)
510 case SASL_GSSAPI:
511 result = Curl_auth_create_gssapi_user_message(data, conn->user,
512 conn->passwd,
513 service,
514 data->easy_conn->host.name,
515 sasl->mutual_auth, NULL,
516 &conn->krb5,
517 &resp, &len);
518 newstate = SASL_GSSAPI_TOKEN;
519 break;
520 case SASL_GSSAPI_TOKEN:
521 sasl->params->getmessage(data->state.buffer, &serverdata);
522 if(sasl->mutual_auth) {
523 /* Decode the user token challenge and create the optional response
524 message */
525 result = Curl_auth_create_gssapi_user_message(data, NULL, NULL,
526 NULL, NULL,
527 sasl->mutual_auth,
528 serverdata, &conn->krb5,
529 &resp, &len);
530 newstate = SASL_GSSAPI_NO_DATA;
531 }
532 else
533 /* Decode the security challenge and create the response message */
534 result = Curl_auth_create_gssapi_security_message(data, serverdata,
535 &conn->krb5,
536 &resp, &len);
537 break;
538 case SASL_GSSAPI_NO_DATA:
539 sasl->params->getmessage(data->state.buffer, &serverdata);
540 /* Decode the security challenge and create the response message */
541 result = Curl_auth_create_gssapi_security_message(data, serverdata,
542 &conn->krb5,
543 &resp, &len);
544 break;
545 #endif
546
547 case SASL_OAUTH2:
548 /* Create the authorisation message */
549 if(sasl->authused == SASL_MECH_OAUTHBEARER) {
550 result = Curl_auth_create_oauth_bearer_message(data, conn->user,
551 hostname,
552 port,
553 conn->oauth_bearer,
554 &resp, &len);
555
556 /* Failures maybe sent by the server as continuations for OAUTHBEARER */
557 newstate = SASL_OAUTH2_RESP;
558 }
559 else
560 result = Curl_auth_create_oauth_bearer_message(data, conn->user,
561 NULL, 0,
562 conn->oauth_bearer,
563 &resp, &len);
564 break;
565
566 case SASL_OAUTH2_RESP:
567 /* The continuation is optional so check the response code */
568 if(code == sasl->params->finalcode) {
569 /* Final response was received so we are done */
570 *progress = SASL_DONE;
571 state(sasl, conn, SASL_STOP);
572 return result;
573 }
574 else if(code == sasl->params->contcode) {
575 /* Acknowledge the continuation by sending a 0x01 response base64
576 encoded */
577 resp = strdup("AQ==");
578 if(!resp)
579 result = CURLE_OUT_OF_MEMORY;
580 break;
581 }
582 else {
583 *progress = SASL_DONE;
584 state(sasl, conn, SASL_STOP);
585 return CURLE_LOGIN_DENIED;
586 }
587
588 case SASL_CANCEL:
589 /* Remove the offending mechanism from the supported list */
590 sasl->authmechs ^= sasl->authused;
591
592 /* Start an alternative SASL authentication */
593 result = Curl_sasl_start(sasl, conn, sasl->force_ir, progress);
594 newstate = sasl->state; /* Use state from Curl_sasl_start() */
595 break;
596 default:
597 failf(data, "Unsupported SASL authentication mechanism");
598 result = CURLE_UNSUPPORTED_PROTOCOL; /* Should not happen */
599 break;
600 }
601
602 switch(result) {
603 case CURLE_BAD_CONTENT_ENCODING:
604 /* Cancel dialog */
605 result = sasl->params->sendcont(conn, "*");
606 newstate = SASL_CANCEL;
607 break;
608 case CURLE_OK:
609 if(resp)
610 result = sasl->params->sendcont(conn, resp);
611 break;
612 default:
613 newstate = SASL_STOP; /* Stop on error */
614 *progress = SASL_DONE;
615 break;
616 }
617
618 free(resp);
619
620 state(sasl, conn, newstate);
621
622 return result;
623 }
624