xref: /third_party/curl/lib/curl_sasl.c (revision 13498266)
1/***************************************************************************
2 *                                  _   _ ____  _
3 *  Project                     ___| | | |  _ \| |
4 *                             / __| | | | |_) | |
5 *                            | (__| |_| |  _ <| |___
6 *                             \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 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.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 * SPDX-License-Identifier: curl
22 *
23 * RFC2195 CRAM-MD5 authentication
24 * RFC2617 Basic and Digest Access Authentication
25 * RFC2831 DIGEST-MD5 authentication
26 * RFC4422 Simple Authentication and Security Layer (SASL)
27 * RFC4616 PLAIN authentication
28 * RFC5802 SCRAM-SHA-1 authentication
29 * RFC7677 SCRAM-SHA-256 authentication
30 * RFC6749 OAuth 2.0 Authorization Framework
31 * RFC7628 A Set of SASL Mechanisms for OAuth
32 * Draft   LOGIN SASL Mechanism <draft-murchison-sasl-login-00.txt>
33 *
34 ***************************************************************************/
35
36#include "curl_setup.h"
37
38#if !defined(CURL_DISABLE_IMAP) || !defined(CURL_DISABLE_SMTP) || \
39  !defined(CURL_DISABLE_POP3) || \
40  (!defined(CURL_DISABLE_LDAP) && defined(USE_OPENLDAP))
41
42#include <curl/curl.h>
43#include "urldata.h"
44
45#include "curl_base64.h"
46#include "curl_md5.h"
47#include "vauth/vauth.h"
48#include "cfilters.h"
49#include "vtls/vtls.h"
50#include "curl_hmac.h"
51#include "curl_sasl.h"
52#include "warnless.h"
53#include "strtok.h"
54#include "sendf.h"
55/* The last 3 #include files should be in this order */
56#include "curl_printf.h"
57#include "curl_memory.h"
58#include "memdebug.h"
59
60/* Supported mechanisms */
61static const struct {
62  const char    *name;  /* Name */
63  size_t         len;   /* Name length */
64  unsigned short bit;   /* Flag bit */
65} mechtable[] = {
66  { "LOGIN",        5,  SASL_MECH_LOGIN },
67  { "PLAIN",        5,  SASL_MECH_PLAIN },
68  { "CRAM-MD5",     8,  SASL_MECH_CRAM_MD5 },
69  { "DIGEST-MD5",   10, SASL_MECH_DIGEST_MD5 },
70  { "GSSAPI",       6,  SASL_MECH_GSSAPI },
71  { "EXTERNAL",     8,  SASL_MECH_EXTERNAL },
72  { "NTLM",         4,  SASL_MECH_NTLM },
73  { "XOAUTH2",      7,  SASL_MECH_XOAUTH2 },
74  { "OAUTHBEARER",  11, SASL_MECH_OAUTHBEARER },
75  { "SCRAM-SHA-1",  11, SASL_MECH_SCRAM_SHA_1 },
76  { "SCRAM-SHA-256",13, SASL_MECH_SCRAM_SHA_256 },
77  { ZERO_NULL,      0,  0 }
78};
79
80/*
81 * Curl_sasl_cleanup()
82 *
83 * This is used to cleanup any libraries or curl modules used by the sasl
84 * functions.
85 *
86 * Parameters:
87 *
88 * conn     [in]     - The connection data.
89 * authused [in]     - The authentication mechanism used.
90 */
91void Curl_sasl_cleanup(struct connectdata *conn, unsigned short authused)
92{
93  (void)conn;
94  (void)authused;
95
96#if defined(USE_KERBEROS5)
97  /* Cleanup the gssapi structure */
98  if(authused == SASL_MECH_GSSAPI) {
99    Curl_auth_cleanup_gssapi(&conn->krb5);
100  }
101#endif
102
103#if defined(USE_GSASL)
104  /* Cleanup the GSASL structure */
105  if(authused & (SASL_MECH_SCRAM_SHA_1 | SASL_MECH_SCRAM_SHA_256)) {
106    Curl_auth_gsasl_cleanup(&conn->gsasl);
107  }
108#endif
109
110#if defined(USE_NTLM)
111  /* Cleanup the NTLM structure */
112  if(authused == SASL_MECH_NTLM) {
113    Curl_auth_cleanup_ntlm(&conn->ntlm);
114  }
115#endif
116}
117
118/*
119 * Curl_sasl_decode_mech()
120 *
121 * Convert a SASL mechanism name into a token.
122 *
123 * Parameters:
124 *
125 * ptr    [in]     - The mechanism string.
126 * maxlen [in]     - Maximum mechanism string length.
127 * len    [out]    - If not NULL, effective name length.
128 *
129 * Returns the SASL mechanism token or 0 if no match.
130 */
131unsigned short Curl_sasl_decode_mech(const char *ptr, size_t maxlen,
132                                     size_t *len)
133{
134  unsigned int i;
135  char c;
136
137  for(i = 0; mechtable[i].name; i++) {
138    if(maxlen >= mechtable[i].len &&
139       !memcmp(ptr, mechtable[i].name, mechtable[i].len)) {
140      if(len)
141        *len = mechtable[i].len;
142
143      if(maxlen == mechtable[i].len)
144        return mechtable[i].bit;
145
146      c = ptr[mechtable[i].len];
147      if(!ISUPPER(c) && !ISDIGIT(c) && c != '-' && c != '_')
148        return mechtable[i].bit;
149    }
150  }
151
152  return 0;
153}
154
155/*
156 * Curl_sasl_parse_url_auth_option()
157 *
158 * Parse the URL login options.
159 */
160CURLcode Curl_sasl_parse_url_auth_option(struct SASL *sasl,
161                                         const char *value, size_t len)
162{
163  CURLcode result = CURLE_OK;
164  size_t mechlen;
165
166  if(!len)
167    return CURLE_URL_MALFORMAT;
168
169  if(sasl->resetprefs) {
170    sasl->resetprefs = FALSE;
171    sasl->prefmech = SASL_AUTH_NONE;
172  }
173
174  if(!strncmp(value, "*", len))
175    sasl->prefmech = SASL_AUTH_DEFAULT;
176  else {
177    unsigned short mechbit = Curl_sasl_decode_mech(value, len, &mechlen);
178    if(mechbit && mechlen == len)
179      sasl->prefmech |= mechbit;
180    else
181      result = CURLE_URL_MALFORMAT;
182  }
183
184  return result;
185}
186
187/*
188 * Curl_sasl_init()
189 *
190 * Initializes the SASL structure.
191 */
192void Curl_sasl_init(struct SASL *sasl, struct Curl_easy *data,
193                    const struct SASLproto *params)
194{
195  unsigned long auth = data->set.httpauth;
196
197  sasl->params = params;           /* Set protocol dependent parameters */
198  sasl->state = SASL_STOP;         /* Not yet running */
199  sasl->curmech = NULL;            /* No mechanism yet. */
200  sasl->authmechs = SASL_AUTH_NONE; /* No known authentication mechanism yet */
201  sasl->prefmech = params->defmechs; /* Default preferred mechanisms */
202  sasl->authused = SASL_AUTH_NONE; /* The authentication mechanism used */
203  sasl->resetprefs = TRUE;         /* Reset prefmech upon AUTH parsing. */
204  sasl->mutual_auth = FALSE;       /* No mutual authentication (GSSAPI only) */
205  sasl->force_ir = FALSE;          /* Respect external option */
206
207  if(auth != CURLAUTH_BASIC) {
208    unsigned short mechs = SASL_AUTH_NONE;
209
210    /* If some usable http authentication options have been set, determine
211       new defaults from them. */
212    if(auth & CURLAUTH_BASIC)
213      mechs |= SASL_MECH_PLAIN | SASL_MECH_LOGIN;
214    if(auth & CURLAUTH_DIGEST)
215      mechs |= SASL_MECH_DIGEST_MD5;
216    if(auth & CURLAUTH_NTLM)
217      mechs |= SASL_MECH_NTLM;
218    if(auth & CURLAUTH_BEARER)
219      mechs |= SASL_MECH_OAUTHBEARER | SASL_MECH_XOAUTH2;
220    if(auth & CURLAUTH_GSSAPI)
221      mechs |= SASL_MECH_GSSAPI;
222
223    if(mechs != SASL_AUTH_NONE)
224      sasl->prefmech = mechs;
225  }
226}
227
228/*
229 * sasl_state()
230 *
231 * This is the ONLY way to change SASL state!
232 */
233static void sasl_state(struct SASL *sasl, struct Curl_easy *data,
234                       saslstate newstate)
235{
236#if defined(DEBUGBUILD) && !defined(CURL_DISABLE_VERBOSE_STRINGS)
237  /* for debug purposes */
238  static const char * const names[]={
239    "STOP",
240    "PLAIN",
241    "LOGIN",
242    "LOGIN_PASSWD",
243    "EXTERNAL",
244    "CRAMMD5",
245    "DIGESTMD5",
246    "DIGESTMD5_RESP",
247    "NTLM",
248    "NTLM_TYPE2MSG",
249    "GSSAPI",
250    "GSSAPI_TOKEN",
251    "GSSAPI_NO_DATA",
252    "OAUTH2",
253    "OAUTH2_RESP",
254    "GSASL",
255    "CANCEL",
256    "FINAL",
257    /* LAST */
258  };
259
260  if(sasl->state != newstate)
261    infof(data, "SASL %p state change from %s to %s",
262          (void *)sasl, names[sasl->state], names[newstate]);
263#else
264  (void) data;
265#endif
266
267  sasl->state = newstate;
268}
269
270#if defined(USE_NTLM) || defined(USE_GSASL) || defined(USE_KERBEROS5) || \
271  !defined(CURL_DISABLE_DIGEST_AUTH)
272/* Get the SASL server message and convert it to binary. */
273static CURLcode get_server_message(struct SASL *sasl, struct Curl_easy *data,
274                                   struct bufref *out)
275{
276  CURLcode result = CURLE_OK;
277
278  result = sasl->params->getmessage(data, out);
279  if(!result && (sasl->params->flags & SASL_FLAG_BASE64)) {
280    unsigned char *msg;
281    size_t msglen;
282    const char *serverdata = (const char *) Curl_bufref_ptr(out);
283
284    if(!*serverdata || *serverdata == '=')
285      Curl_bufref_set(out, NULL, 0, NULL);
286    else {
287      result = Curl_base64_decode(serverdata, &msg, &msglen);
288      if(!result)
289        Curl_bufref_set(out, msg, msglen, curl_free);
290    }
291  }
292  return result;
293}
294#endif
295
296/* Encode the outgoing SASL message. */
297static CURLcode build_message(struct SASL *sasl, struct bufref *msg)
298{
299  CURLcode result = CURLE_OK;
300
301  if(sasl->params->flags & SASL_FLAG_BASE64) {
302    if(!Curl_bufref_ptr(msg))                   /* Empty message. */
303      Curl_bufref_set(msg, "", 0, NULL);
304    else if(!Curl_bufref_len(msg))              /* Explicit empty response. */
305      Curl_bufref_set(msg, "=", 1, NULL);
306    else {
307      char *base64;
308      size_t base64len;
309
310      result = Curl_base64_encode((const char *) Curl_bufref_ptr(msg),
311                                  Curl_bufref_len(msg), &base64, &base64len);
312      if(!result)
313        Curl_bufref_set(msg, base64, base64len, curl_free);
314    }
315  }
316
317  return result;
318}
319
320/*
321 * Curl_sasl_can_authenticate()
322 *
323 * Check if we have enough auth data and capabilities to authenticate.
324 */
325bool Curl_sasl_can_authenticate(struct SASL *sasl, struct Curl_easy *data)
326{
327  /* Have credentials been provided? */
328  if(data->state.aptr.user)
329    return TRUE;
330
331  /* EXTERNAL can authenticate without a user name and/or password */
332  if(sasl->authmechs & sasl->prefmech & SASL_MECH_EXTERNAL)
333    return TRUE;
334
335  return FALSE;
336}
337
338/*
339 * Curl_sasl_start()
340 *
341 * Calculate the required login details for SASL authentication.
342 */
343CURLcode Curl_sasl_start(struct SASL *sasl, struct Curl_easy *data,
344                         bool force_ir, saslprogress *progress)
345{
346  CURLcode result = CURLE_OK;
347  struct connectdata *conn = data->conn;
348  unsigned short enabledmechs;
349  const char *mech = NULL;
350  struct bufref resp;
351  saslstate state1 = SASL_STOP;
352  saslstate state2 = SASL_FINAL;
353  const char *hostname, *disp_hostname;
354  int port;
355#if defined(USE_KERBEROS5) || defined(USE_NTLM)
356  const char *service = data->set.str[STRING_SERVICE_NAME] ?
357    data->set.str[STRING_SERVICE_NAME] :
358    sasl->params->service;
359#endif
360  const char *oauth_bearer = data->set.str[STRING_BEARER];
361  struct bufref nullmsg;
362
363  Curl_conn_get_host(data, FIRSTSOCKET, &hostname, &disp_hostname, &port);
364  Curl_bufref_init(&nullmsg);
365  Curl_bufref_init(&resp);
366  sasl->force_ir = force_ir;    /* Latch for future use */
367  sasl->authused = 0;           /* No mechanism used yet */
368  enabledmechs = sasl->authmechs & sasl->prefmech;
369  *progress = SASL_IDLE;
370
371  /* Calculate the supported authentication mechanism, by decreasing order of
372     security, as well as the initial response where appropriate */
373  if((enabledmechs & SASL_MECH_EXTERNAL) && !conn->passwd[0]) {
374    mech = SASL_MECH_STRING_EXTERNAL;
375    state1 = SASL_EXTERNAL;
376    sasl->authused = SASL_MECH_EXTERNAL;
377
378    if(force_ir || data->set.sasl_ir)
379      result = Curl_auth_create_external_message(conn->user, &resp);
380  }
381  else if(data->state.aptr.user) {
382#if defined(USE_KERBEROS5)
383    if((enabledmechs & SASL_MECH_GSSAPI) && Curl_auth_is_gssapi_supported() &&
384       Curl_auth_user_contains_domain(conn->user)) {
385      sasl->mutual_auth = FALSE;
386      mech = SASL_MECH_STRING_GSSAPI;
387      state1 = SASL_GSSAPI;
388      state2 = SASL_GSSAPI_TOKEN;
389      sasl->authused = SASL_MECH_GSSAPI;
390
391      if(force_ir || data->set.sasl_ir)
392        result = Curl_auth_create_gssapi_user_message(data, conn->user,
393                                                      conn->passwd,
394                                                      service,
395                                                      conn->host.name,
396                                                      sasl->mutual_auth,
397                                                      NULL, &conn->krb5,
398                                                      &resp);
399    }
400    else
401#endif
402#ifdef USE_GSASL
403    if((enabledmechs & SASL_MECH_SCRAM_SHA_256) &&
404       Curl_auth_gsasl_is_supported(data, SASL_MECH_STRING_SCRAM_SHA_256,
405                                    &conn->gsasl)) {
406      mech = SASL_MECH_STRING_SCRAM_SHA_256;
407      sasl->authused = SASL_MECH_SCRAM_SHA_256;
408      state1 = SASL_GSASL;
409      state2 = SASL_GSASL;
410
411      result = Curl_auth_gsasl_start(data, conn->user,
412                                     conn->passwd, &conn->gsasl);
413      if(result == CURLE_OK && (force_ir || data->set.sasl_ir))
414        result = Curl_auth_gsasl_token(data, &nullmsg, &conn->gsasl, &resp);
415    }
416    else if((enabledmechs & SASL_MECH_SCRAM_SHA_1) &&
417            Curl_auth_gsasl_is_supported(data, SASL_MECH_STRING_SCRAM_SHA_1,
418                                         &conn->gsasl)) {
419      mech = SASL_MECH_STRING_SCRAM_SHA_1;
420      sasl->authused = SASL_MECH_SCRAM_SHA_1;
421      state1 = SASL_GSASL;
422      state2 = SASL_GSASL;
423
424      result = Curl_auth_gsasl_start(data, conn->user,
425                                     conn->passwd, &conn->gsasl);
426      if(result == CURLE_OK && (force_ir || data->set.sasl_ir))
427        result = Curl_auth_gsasl_token(data, &nullmsg, &conn->gsasl, &resp);
428    }
429    else
430#endif
431#ifndef CURL_DISABLE_DIGEST_AUTH
432    if((enabledmechs & SASL_MECH_DIGEST_MD5) &&
433       Curl_auth_is_digest_supported()) {
434      mech = SASL_MECH_STRING_DIGEST_MD5;
435      state1 = SASL_DIGESTMD5;
436      sasl->authused = SASL_MECH_DIGEST_MD5;
437    }
438    else if(enabledmechs & SASL_MECH_CRAM_MD5) {
439      mech = SASL_MECH_STRING_CRAM_MD5;
440      state1 = SASL_CRAMMD5;
441      sasl->authused = SASL_MECH_CRAM_MD5;
442    }
443    else
444#endif
445#ifdef USE_NTLM
446    if((enabledmechs & SASL_MECH_NTLM) && Curl_auth_is_ntlm_supported()) {
447      mech = SASL_MECH_STRING_NTLM;
448      state1 = SASL_NTLM;
449      state2 = SASL_NTLM_TYPE2MSG;
450      sasl->authused = SASL_MECH_NTLM;
451
452      if(force_ir || data->set.sasl_ir)
453        result = Curl_auth_create_ntlm_type1_message(data,
454                                                     conn->user, conn->passwd,
455                                                     service,
456                                                     hostname,
457                                                     &conn->ntlm, &resp);
458      }
459    else
460#endif
461    if((enabledmechs & SASL_MECH_OAUTHBEARER) && oauth_bearer) {
462      mech = SASL_MECH_STRING_OAUTHBEARER;
463      state1 = SASL_OAUTH2;
464      state2 = SASL_OAUTH2_RESP;
465      sasl->authused = SASL_MECH_OAUTHBEARER;
466
467      if(force_ir || data->set.sasl_ir)
468        result = Curl_auth_create_oauth_bearer_message(conn->user,
469                                                       hostname,
470                                                       port,
471                                                       oauth_bearer,
472                                                       &resp);
473    }
474    else if((enabledmechs & SASL_MECH_XOAUTH2) && oauth_bearer) {
475      mech = SASL_MECH_STRING_XOAUTH2;
476      state1 = SASL_OAUTH2;
477      sasl->authused = SASL_MECH_XOAUTH2;
478
479      if(force_ir || data->set.sasl_ir)
480        result = Curl_auth_create_xoauth_bearer_message(conn->user,
481                                                        oauth_bearer,
482                                                        &resp);
483    }
484    else if(enabledmechs & SASL_MECH_PLAIN) {
485      mech = SASL_MECH_STRING_PLAIN;
486      state1 = SASL_PLAIN;
487      sasl->authused = SASL_MECH_PLAIN;
488
489      if(force_ir || data->set.sasl_ir)
490        result = Curl_auth_create_plain_message(conn->sasl_authzid,
491                                                conn->user, conn->passwd,
492                                                &resp);
493    }
494    else if(enabledmechs & SASL_MECH_LOGIN) {
495      mech = SASL_MECH_STRING_LOGIN;
496      state1 = SASL_LOGIN;
497      state2 = SASL_LOGIN_PASSWD;
498      sasl->authused = SASL_MECH_LOGIN;
499
500      if(force_ir || data->set.sasl_ir)
501        result = Curl_auth_create_login_message(conn->user, &resp);
502    }
503  }
504
505  if(!result && mech) {
506    sasl->curmech = mech;
507    if(Curl_bufref_ptr(&resp))
508      result = build_message(sasl, &resp);
509
510    if(sasl->params->maxirlen &&
511       strlen(mech) + Curl_bufref_len(&resp) > sasl->params->maxirlen)
512      Curl_bufref_free(&resp);
513
514    if(!result)
515      result = sasl->params->sendauth(data, mech, &resp);
516
517    if(!result) {
518      *progress = SASL_INPROGRESS;
519      sasl_state(sasl, data, Curl_bufref_ptr(&resp) ? state2 : state1);
520    }
521  }
522
523  Curl_bufref_free(&resp);
524  return result;
525}
526
527/*
528 * Curl_sasl_continue()
529 *
530 * Continue the authentication.
531 */
532CURLcode Curl_sasl_continue(struct SASL *sasl, struct Curl_easy *data,
533                            int code, saslprogress *progress)
534{
535  CURLcode result = CURLE_OK;
536  struct connectdata *conn = data->conn;
537  saslstate newstate = SASL_FINAL;
538  struct bufref resp;
539  const char *hostname, *disp_hostname;
540  int port;
541#if defined(USE_KERBEROS5) || defined(USE_NTLM) \
542    || !defined(CURL_DISABLE_DIGEST_AUTH)
543  const char *service = data->set.str[STRING_SERVICE_NAME] ?
544    data->set.str[STRING_SERVICE_NAME] :
545    sasl->params->service;
546#endif
547  const char *oauth_bearer = data->set.str[STRING_BEARER];
548  struct bufref serverdata;
549
550  Curl_conn_get_host(data, FIRSTSOCKET, &hostname, &disp_hostname, &port);
551  Curl_bufref_init(&serverdata);
552  Curl_bufref_init(&resp);
553  *progress = SASL_INPROGRESS;
554
555  if(sasl->state == SASL_FINAL) {
556    if(code != sasl->params->finalcode)
557      result = CURLE_LOGIN_DENIED;
558    *progress = SASL_DONE;
559    sasl_state(sasl, data, SASL_STOP);
560    return result;
561  }
562
563  if(sasl->state != SASL_CANCEL && sasl->state != SASL_OAUTH2_RESP &&
564     code != sasl->params->contcode) {
565    *progress = SASL_DONE;
566    sasl_state(sasl, data, SASL_STOP);
567    return CURLE_LOGIN_DENIED;
568  }
569
570  switch(sasl->state) {
571  case SASL_STOP:
572    *progress = SASL_DONE;
573    return result;
574  case SASL_PLAIN:
575    result = Curl_auth_create_plain_message(conn->sasl_authzid,
576                                            conn->user, conn->passwd, &resp);
577    break;
578  case SASL_LOGIN:
579    result = Curl_auth_create_login_message(conn->user, &resp);
580    newstate = SASL_LOGIN_PASSWD;
581    break;
582  case SASL_LOGIN_PASSWD:
583    result = Curl_auth_create_login_message(conn->passwd, &resp);
584    break;
585  case SASL_EXTERNAL:
586    result = Curl_auth_create_external_message(conn->user, &resp);
587    break;
588#ifdef USE_GSASL
589  case SASL_GSASL:
590    result = get_server_message(sasl, data, &serverdata);
591    if(!result)
592      result = Curl_auth_gsasl_token(data, &serverdata, &conn->gsasl, &resp);
593    if(!result && Curl_bufref_len(&resp) > 0)
594      newstate = SASL_GSASL;
595    break;
596#endif
597#ifndef CURL_DISABLE_DIGEST_AUTH
598  case SASL_CRAMMD5:
599    result = get_server_message(sasl, data, &serverdata);
600    if(!result)
601      result = Curl_auth_create_cram_md5_message(&serverdata, conn->user,
602                                                 conn->passwd, &resp);
603    break;
604  case SASL_DIGESTMD5:
605    result = get_server_message(sasl, data, &serverdata);
606    if(!result)
607      result = Curl_auth_create_digest_md5_message(data, &serverdata,
608                                                   conn->user, conn->passwd,
609                                                   service, &resp);
610    if(!result && (sasl->params->flags & SASL_FLAG_BASE64))
611      newstate = SASL_DIGESTMD5_RESP;
612    break;
613  case SASL_DIGESTMD5_RESP:
614    /* Keep response NULL to output an empty line. */
615    break;
616#endif
617
618#ifdef USE_NTLM
619  case SASL_NTLM:
620    /* Create the type-1 message */
621    result = Curl_auth_create_ntlm_type1_message(data,
622                                                 conn->user, conn->passwd,
623                                                 service, hostname,
624                                                 &conn->ntlm, &resp);
625    newstate = SASL_NTLM_TYPE2MSG;
626    break;
627  case SASL_NTLM_TYPE2MSG:
628    /* Decode the type-2 message */
629    result = get_server_message(sasl, data, &serverdata);
630    if(!result)
631      result = Curl_auth_decode_ntlm_type2_message(data, &serverdata,
632                                                   &conn->ntlm);
633    if(!result)
634      result = Curl_auth_create_ntlm_type3_message(data, conn->user,
635                                                   conn->passwd, &conn->ntlm,
636                                                   &resp);
637    break;
638#endif
639
640#if defined(USE_KERBEROS5)
641  case SASL_GSSAPI:
642    result = Curl_auth_create_gssapi_user_message(data, conn->user,
643                                                  conn->passwd,
644                                                  service,
645                                                  conn->host.name,
646                                                  sasl->mutual_auth, NULL,
647                                                  &conn->krb5,
648                                                  &resp);
649    newstate = SASL_GSSAPI_TOKEN;
650    break;
651  case SASL_GSSAPI_TOKEN:
652    result = get_server_message(sasl, data, &serverdata);
653    if(!result) {
654      if(sasl->mutual_auth) {
655        /* Decode the user token challenge and create the optional response
656           message */
657        result = Curl_auth_create_gssapi_user_message(data, NULL, NULL,
658                                                      NULL, NULL,
659                                                      sasl->mutual_auth,
660                                                      &serverdata,
661                                                      &conn->krb5,
662                                                      &resp);
663        newstate = SASL_GSSAPI_NO_DATA;
664      }
665      else
666        /* Decode the security challenge and create the response message */
667        result = Curl_auth_create_gssapi_security_message(data,
668                                                          conn->sasl_authzid,
669                                                          &serverdata,
670                                                          &conn->krb5,
671                                                          &resp);
672    }
673    break;
674  case SASL_GSSAPI_NO_DATA:
675    /* Decode the security challenge and create the response message */
676    result = get_server_message(sasl, data, &serverdata);
677    if(!result)
678      result = Curl_auth_create_gssapi_security_message(data,
679                                                        conn->sasl_authzid,
680                                                        &serverdata,
681                                                        &conn->krb5,
682                                                        &resp);
683    break;
684#endif
685
686  case SASL_OAUTH2:
687    /* Create the authorization message */
688    if(sasl->authused == SASL_MECH_OAUTHBEARER) {
689      result = Curl_auth_create_oauth_bearer_message(conn->user,
690                                                     hostname,
691                                                     port,
692                                                     oauth_bearer,
693                                                     &resp);
694
695      /* Failures maybe sent by the server as continuations for OAUTHBEARER */
696      newstate = SASL_OAUTH2_RESP;
697    }
698    else
699      result = Curl_auth_create_xoauth_bearer_message(conn->user,
700                                                      oauth_bearer,
701                                                      &resp);
702    break;
703
704  case SASL_OAUTH2_RESP:
705    /* The continuation is optional so check the response code */
706    if(code == sasl->params->finalcode) {
707      /* Final response was received so we are done */
708      *progress = SASL_DONE;
709      sasl_state(sasl, data, SASL_STOP);
710      return result;
711    }
712    else if(code == sasl->params->contcode) {
713      /* Acknowledge the continuation by sending a 0x01 response. */
714      Curl_bufref_set(&resp, "\x01", 1, NULL);
715      break;
716    }
717    else {
718      *progress = SASL_DONE;
719      sasl_state(sasl, data, SASL_STOP);
720      return CURLE_LOGIN_DENIED;
721    }
722
723  case SASL_CANCEL:
724    /* Remove the offending mechanism from the supported list */
725    sasl->authmechs ^= sasl->authused;
726
727    /* Start an alternative SASL authentication */
728    return Curl_sasl_start(sasl, data, sasl->force_ir, progress);
729  default:
730    failf(data, "Unsupported SASL authentication mechanism");
731    result = CURLE_UNSUPPORTED_PROTOCOL;  /* Should not happen */
732    break;
733  }
734
735  Curl_bufref_free(&serverdata);
736
737  switch(result) {
738  case CURLE_BAD_CONTENT_ENCODING:
739    /* Cancel dialog */
740    result = sasl->params->cancelauth(data, sasl->curmech);
741    newstate = SASL_CANCEL;
742    break;
743  case CURLE_OK:
744    result = build_message(sasl, &resp);
745    if(!result)
746      result = sasl->params->contauth(data, sasl->curmech, &resp);
747    break;
748  default:
749    newstate = SASL_STOP;    /* Stop on error */
750    *progress = SASL_DONE;
751    break;
752  }
753
754  Curl_bufref_free(&resp);
755
756  sasl_state(sasl, data, newstate);
757
758  return result;
759}
760#endif /* protocols are enabled that use SASL */
761