plugins/gs2.c

   1 /*
   2  * Copyright (c) 2010, JANET(UK)
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  *
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * 3. Neither the name of JANET(UK) nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  21  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32 /*
  33  * Copyright (c) 1998-2003 Carnegie Mellon University.
  34  * All rights reserved.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  *
  40  * 1. Redistributions of source code must retain the above copyright
  41  *    notice, this list of conditions and the following disclaimer.
  42  *
  43  * 2. Redistributions in binary form must reproduce the above copyright
  44  *    notice, this list of conditions and the following disclaimer in
  45  *    the documentation and/or other materials provided with the
  46  *    distribution.
  47  *
  48  * 3. The name "Carnegie Mellon University" must not be used to
  49  *    endorse or promote products derived from this software without
  50  *    prior written permission. For permission or any other legal
  51  *    details, please contact
  52  *      Office of Technology Transfer
  53  *      Carnegie Mellon University
  54  *      5000 Forbes Avenue
  55  *      Pittsburgh, PA  15213-3890
  56  *      (412) 268-4387, fax: (412) 268-7395
  57  *      tech-transfer@andrew.cmu.edu
  58  *
  59  * 4. Redistributions of any form whatsoever must retain the following
  60  *    acknowledgment:
  61  *    "This product includes software developed by Computing Services
  62  *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
  63  *
  64  * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
  65  * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  66  * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
  67  * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  68  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
  69  * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
  70  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  71  */
  72
  73 #include <config.h>
  74 #include <gssapi/gssapi.h>
  75 #ifdef HAVE_GSSAPI_GSSAPI_EXT_H
  76 #include <gssapi/gssapi_ext.h>
  77 #endif
  78 #include <fcntl.h>
  79 #include <stdio.h>
  80 #include <sasl.h>
  81 #include <saslutil.h>
  82 #include <saslplug.h>
  83
  84 #include "plugin_common.h"
  85
  86 #ifdef HAVE_UNISTD_H
  87 #include <unistd.h>
  88 #endif
  89
  90 #include <errno.h>
  91 #include <assert.h>
  92 #include "gs2_token.h"
  93
  94 #define GS2_CB_FLAG_MASK    0x0F
  95 #define GS2_CB_FLAG_N       0x00
  96 #define GS2_CB_FLAG_P       0x01
  97 #define GS2_CB_FLAG_Y       0x02
  98 #define GS2_NONSTD_FLAG     0x10
  99
 100 typedef struct context {
 101     gss_ctx_id_t gss_ctx;
 102     gss_name_t client_name;
 103     gss_name_t server_name;
 104     gss_cred_id_t server_creds;
 105     gss_cred_id_t client_creds;
 106     char *out_buf;
 107     unsigned out_buf_len;
 108     const sasl_utils_t *utils;
 109     char *authid;
 110     char *authzid;
 111     union {
 112         sasl_client_plug_t *client;
 113         sasl_server_plug_t *server;
 114     } plug;
 115     gss_OID mechanism;
 116     int gs2_flags;
 117     char *cbindingname;
 118     struct gss_channel_bindings_struct gss_cbindings;
 119     sasl_secret_t *password;
 120     unsigned int free_password;
 121     OM_uint32 lifetime;
 122 } context_t;
 123
 124 static gss_OID_set gs2_mechs = GSS_C_NO_OID_SET;
 125
 126 static int gs2_get_init_creds(context_t *context,
 127                               sasl_client_params_t *params,
 128                               sasl_interact_t **prompt_need,
 129                               sasl_out_params_t *oparams);
 130
 131 static int gs2_verify_initial_message(context_t *text,
 132                                       sasl_server_params_t *sparams,
 133                                       const char *in,
 134                                       unsigned inlen,
 135                                       gss_buffer_t token);
 136
 137 static int gs2_make_header(context_t *text,
 138                            sasl_client_params_t *cparams,
 139                            const char *authzid,
 140                            char **out,
 141                            unsigned *outlen);
 142
 143 static int gs2_make_message(context_t *text,
 144                             sasl_client_params_t *cparams,
 145                             int initialContextToken,
 146                             gss_buffer_t token,
 147                             char **out,
 148                             unsigned *outlen);
 149
 150 static int gs2_get_mech_attrs(const sasl_utils_t *utils,
 151                               const gss_OID mech,
 152                               unsigned int *security_flags,
 153                               unsigned int *features,
 154                               const unsigned long **prompts);
 155
 156 static int gs2_indicate_mechs(const sasl_utils_t *utils);
 157
 158 static int gs2_map_sasl_name(const sasl_utils_t *utils,
 159                              const char *mech,
 160                              gss_OID *oid);
 161
 162 static int gs2_duplicate_buffer(const sasl_utils_t *utils,
 163                                 const gss_buffer_t src,
 164                                 gss_buffer_t dst);
 165
 166 static int gs2_unescape_authzid(const sasl_utils_t *utils,
 167                                 char **in,
 168                                 unsigned *inlen,
 169                                 char **authzid);
 170
 171 static int gs2_escape_authzid(const sasl_utils_t *utils,
 172                               const char *in,
 173                               unsigned inlen,
 174                               char **authzid);
 175
 176 /* sasl_gs_log: only logs status string returned from gss_display_status() */
 177 #define sasl_gs2_log(x,y,z) sasl_gs2_seterror_(x,y,z,1)
 178 #define sasl_gs2_seterror(x,y,z) sasl_gs2_seterror_(x,y,z,0)
 179
 180 static int
 181 sasl_gs2_seterror_(const sasl_utils_t *utils, OM_uint32 maj, OM_uint32 min,
 182                    int logonly);
 183
 184 static context_t *
 185 sasl_gs2_new_context(const sasl_utils_t *utils)
 186 {
 187     context_t *ret;
 188
 189     ret = utils->malloc(sizeof(context_t));
 190     if (ret == NULL)
 191         return NULL;
 192
 193     memset(ret, 0, sizeof(context_t));
 194     ret->utils = utils;
 195
 196     return ret;
 197 }
 198
 199 static int
 200 sasl_gs2_free_context_contents(context_t *text)
 201 {
 202     OM_uint32 min_stat;
 203
 204     if (text == NULL)
 205         return SASL_OK;
 206
 207     if (text->gss_ctx != GSS_C_NO_CONTEXT) {
 208         gss_delete_sec_context(&min_stat,&text->gss_ctx,
 209                                GSS_C_NO_BUFFER);
 210         text->gss_ctx = GSS_C_NO_CONTEXT;
 211     }
 212
 213     if (text->client_name != GSS_C_NO_NAME) {
 214         gss_release_name(&min_stat,&text->client_name);
 215         text->client_name = GSS_C_NO_NAME;
 216     }
 217
 218     if (text->server_name != GSS_C_NO_NAME) {
 219         gss_release_name(&min_stat,&text->server_name);
 220         text->server_name = GSS_C_NO_NAME;
 221     }
 222
 223     if (text->server_creds != GSS_C_NO_CREDENTIAL) {
 224         gss_release_cred(&min_stat, &text->server_creds);
 225         text->server_creds = GSS_C_NO_CREDENTIAL;
 226     }
 227
 228     if (text->client_creds != GSS_C_NO_CREDENTIAL) {
 229         gss_release_cred(&min_stat, &text->client_creds);
 230         text->client_creds = GSS_C_NO_CREDENTIAL;
 231     }
 232
 233     if (text->authid != NULL) {
 234         text->utils->free(text->authid);
 235         text->authid = NULL;
 236     }
 237
 238     if (text->authzid != NULL) {
 239         text->utils->free(text->authzid);
 240         text->authzid = NULL;
 241     }
 242
 243     gss_release_buffer(&min_stat, &text->gss_cbindings.application_data);
 244
 245     if (text->out_buf != NULL) {
 246         text->utils->free(text->out_buf);
 247         text->out_buf = NULL;
 248     }
 249
 250     text->out_buf_len = 0;
 251
 252     if (text->cbindingname != NULL) {
 253         text->utils->free(text->cbindingname);
 254         text->cbindingname = NULL;
 255     }
 256
 257     if (text->free_password)
 258         _plug_free_secret(text->utils, &text->password);
 259
 260     memset(text, 0, sizeof(*text));
 261
 262     return SASL_OK;
 263 }
 264
 265 static void
 266 gs2_common_mech_dispose(void *conn_context, const sasl_utils_t *utils)
 267 {
 268     sasl_gs2_free_context_contents((context_t *)(conn_context));
 269     utils->free(conn_context);
 270 }
 271
 272 static void
 273 gs2_common_mech_free(void *global_context __attribute__((unused)),
 274                      const sasl_utils_t *utils)
 275 {
 276     OM_uint32 minor;
 277
 278     if (gs2_mechs != GSS_C_NO_OID_SET) {
 279         gss_release_oid_set(&minor, &gs2_mechs);
 280         gs2_mechs = GSS_C_NO_OID_SET;
 281     }
 282 }
 283
 284 /*****************************  Server Section  *****************************/
 285
 286 static int
 287 gs2_server_mech_new(void *glob_context,
 288                     sasl_server_params_t *params,
 289                     const char *challenge __attribute__((unused)),
 290                     unsigned challen __attribute__((unused)),
 291                     void **conn_context)
 292 {
 293     context_t *text;
 294     int ret;
 295
 296     text = sasl_gs2_new_context(params->utils);
 297     if (text == NULL) {
 298         MEMERROR(params->utils);
 299         return SASL_NOMEM;
 300     }
 301
 302     text->gss_ctx = GSS_C_NO_CONTEXT;
 303     text->client_name = GSS_C_NO_NAME;
 304     text->server_name = GSS_C_NO_NAME;
 305     text->server_creds = GSS_C_NO_CREDENTIAL;
 306     text->client_creds = GSS_C_NO_CREDENTIAL;
 307     text->plug.server = glob_context;
 308
 309     ret = gs2_map_sasl_name(params->utils, text->plug.server->mech_name,
 310                             &text->mechanism);
 311     if (ret != SASL_OK) {
 312         gs2_common_mech_dispose(text, params->utils);
 313         return ret;
 314     }
 315
 316     *conn_context = text;
 317
 318     return SASL_OK;
 319 }
 320
 321 static int
 322 gs2_server_mech_step(void *conn_context,
 323                      sasl_server_params_t *params,
 324                      const char *clientin,
 325                      unsigned clientinlen,
 326                      const char **serverout,
 327                      unsigned *serveroutlen,
 328                      sasl_out_params_t *oparams)
 329 {
 330     context_t *text = (context_t *)conn_context;
 331     gss_buffer_desc input_token = GSS_C_EMPTY_BUFFER;
 332     gss_buffer_desc output_token = GSS_C_EMPTY_BUFFER;
 333     OM_uint32 maj_stat = GSS_S_FAILURE, min_stat = 0;
 334     gss_buffer_desc name_buf = GSS_C_EMPTY_BUFFER;
 335     gss_buffer_desc short_name_buf = GSS_C_EMPTY_BUFFER;
 336     gss_name_t without = GSS_C_NO_NAME;
 337     gss_OID_set_desc mechs;
 338     OM_uint32 out_flags = 0;
 339     int ret = 0, equal = 0;
 340     int initialContextToken = (text->gss_ctx == GSS_C_NO_CONTEXT);
 341     char *p;
 342
 343     if (serverout == NULL) {
 344         PARAMERROR(text->utils);
 345         return SASL_BADPARAM;
 346     }
 347
 348     *serverout = NULL;
 349     *serveroutlen = 0;
 350
 351     if (initialContextToken) {
 352         name_buf.length = strlen(params->service) + 1 + strlen(params->serverFQDN);
 353         name_buf.value = params->utils->malloc(name_buf.length + 1);
 354         if (name_buf.value == NULL) {
 355             MEMERROR(text->utils);
 356             ret = SASL_NOMEM;
 357             goto cleanup;
 358         }
 359         snprintf(name_buf.value, name_buf.length + 1,
 360                  "%s@%s", params->service, params->serverFQDN);
 361         maj_stat = gss_import_name(&min_stat,
 362                                    &name_buf,
 363                                    GSS_C_NT_HOSTBASED_SERVICE,
 364                                    &text->server_name);
 365         params->utils->free(name_buf.value);
 366         name_buf.value = NULL;
 367
 368         if (GSS_ERROR(maj_stat))
 369             goto cleanup;
 370
 371         assert(text->server_creds == GSS_C_NO_CREDENTIAL);
 372
 373         mechs.count = 1;
 374         mechs.elements = (gss_OID)text->mechanism;
 375
 376         if (params->gss_creds == GSS_C_NO_CREDENTIAL) {
 377             maj_stat = gss_acquire_cred(&min_stat,
 378                                         text->server_name,
 379                                         GSS_C_INDEFINITE,
 380                                         &mechs,
 381                                         GSS_C_ACCEPT,
 382                                         &text->server_creds,
 383                                         NULL,
 384                                         &text->lifetime);
 385             if (GSS_ERROR(maj_stat))
 386                 goto cleanup;
 387         }
 388
 389         ret = gs2_verify_initial_message(text,
 390                                          params,
 391                                          clientin,
 392                                          clientinlen,
 393                                          &input_token);
 394         if (ret != SASL_OK)
 395             goto cleanup;
 396     } else {
 397         input_token.value = (void *)clientin;
 398         input_token.length = clientinlen;
 399     }
 400
 401     maj_stat = gss_accept_sec_context(&min_stat,
 402                                       &text->gss_ctx,
 403                                       (params->gss_creds != GSS_C_NO_CREDENTIAL)
 404                                         ? (gss_cred_id_t)params->gss_creds
 405                                         : text->server_creds,
 406                                       &input_token,
 407                                       &text->gss_cbindings,
 408                                       &text->client_name,
 409                                       NULL,
 410                                       &output_token,
 411                                       &out_flags,
 412                                       &text->lifetime,
 413                                       &text->client_creds);
 414     if (GSS_ERROR(maj_stat)) {
 415         sasl_gs2_log(text->utils, maj_stat, min_stat);
 416         text->utils->seterror(text->utils->conn, SASL_NOLOG,
 417                               "GS2 Failure: gss_accept_sec_context");
 418         ret = (maj_stat == GSS_S_BAD_BINDINGS) ? SASL_BADBINDING : SASL_BADAUTH;
 419         goto cleanup;
 420     }
 421
 422     *serveroutlen = output_token.length;
 423     if (output_token.value != NULL) {
 424         ret = _plug_buf_alloc(text->utils, &text->out_buf,
 425                               &text->out_buf_len, *serveroutlen);
 426         if (ret != SASL_OK)
 427             goto cleanup;
 428         memcpy(text->out_buf, output_token.value, *serveroutlen);
 429         *serverout = text->out_buf;
 430     } else {
 431         /* No output token, send an empty string */
 432         *serverout = "";
 433         serveroutlen = 0;
 434     }
 435
 436     if (maj_stat == GSS_S_CONTINUE_NEEDED) {
 437         ret = SASL_CONTINUE;
 438         goto cleanup;
 439     }
 440
 441     assert(maj_stat == GSS_S_COMPLETE);
 442
 443     maj_stat = gss_display_name(&min_stat, text->client_name,
 444                                 &name_buf, NULL);
 445     if (GSS_ERROR(maj_stat))
 446         goto cleanup;
 447
 448     ret = gs2_duplicate_buffer(params->utils, &name_buf, &short_name_buf);
 449     if (ret != 0)
 450         goto cleanup;
 451
 452     p = (char *)memchr(name_buf.value, '@', name_buf.length);
 453     if (p != NULL) {
 454         short_name_buf.length = (p - (char *)name_buf.value);
 455
 456         maj_stat = gss_import_name(&min_stat,
 457                                    &short_name_buf,
 458                                    GSS_C_NT_USER_NAME,
 459                                    &without);
 460         if (GSS_ERROR(maj_stat)) {
 461             ret = SASL_FAIL;
 462             goto cleanup;
 463         }
 464
 465         maj_stat = gss_compare_name(&min_stat, text->client_name,
 466                                     without, &equal);
 467         if (GSS_ERROR(maj_stat)) {
 468             ret = SASL_FAIL;
 469             goto cleanup;
 470         }
 471
 472         if (equal)
 473             ((char *)short_name_buf.value)[short_name_buf.length] = '\0';
 474     }
 475
 476     text->authid = (char *)short_name_buf.value;
 477     short_name_buf.value = NULL;
 478     short_name_buf.length = 0;
 479
 480     if (text->authzid != NULL) {
 481         ret = params->canon_user(params->utils->conn,
 482                                  text->authzid, 0,
 483                                  SASL_CU_AUTHZID, oparams);
 484         if (ret != SASL_OK)
 485             goto cleanup;
 486     }
 487
 488     ret = params->canon_user(params->utils->conn,
 489                              text->authid, 0,
 490                              text->authzid == NULL
 491                                 ? (SASL_CU_AUTHZID | SASL_CU_AUTHID)
 492                                 : SASL_CU_AUTHID,
 493                              oparams);
 494     if (ret != SASL_OK)
 495         goto cleanup;
 496
 497     switch (text->gs2_flags & GS2_CB_FLAG_MASK) {
 498     case GS2_CB_FLAG_N:
 499         oparams->cbindingdisp = SASL_CB_DISP_NONE;
 500         break;
 501     case GS2_CB_FLAG_P:
 502         oparams->cbindingdisp = SASL_CB_DISP_USED;
 503         oparams->cbindingname = text->cbindingname;
 504         break;
 505     case GS2_CB_FLAG_Y:
 506         oparams->cbindingdisp = SASL_CB_DISP_WANT;
 507         break;
 508     }
 509
 510     if (text->client_creds != GSS_C_NO_CREDENTIAL)
 511         oparams->client_creds = &text->client_creds;
 512     else
 513         oparams->client_creds = NULL;
 514
 515     oparams->gss_peer_name = text->client_name;
 516     oparams->gss_local_name = text->server_name;
 517     oparams->maxoutbuf = 0xFFFFFF;
 518     oparams->encode = NULL;
 519     oparams->decode = NULL;
 520     oparams->mech_ssf = 0;
 521     oparams->doneflag = 1;
 522
 523     ret = SASL_OK;
 524
 525 cleanup:
 526     if (initialContextToken)
 527         gss_release_buffer(&min_stat, &input_token);
 528     gss_release_buffer(&min_stat, &name_buf);
 529     gss_release_buffer(&min_stat, &short_name_buf);
 530     gss_release_buffer(&min_stat, &output_token);
 531     gss_release_name(&min_stat, &without);
 532
 533     if (ret == SASL_OK && maj_stat != GSS_S_COMPLETE) {
 534         sasl_gs2_seterror(text->utils, maj_stat, min_stat);
 535         ret = SASL_FAIL;
 536     }
 537     if (ret < SASL_OK)
 538         sasl_gs2_free_context_contents(text);
 539
 540     return ret;
 541 }
 542
 543 static int
 544 gs2_common_plug_init(const sasl_utils_t *utils,
 545                      size_t plugsize,
 546                      int (*plug_alloc)(const sasl_utils_t *,
 547                                        void *,
 548                                        const gss_buffer_t,
 549                                        const gss_OID),
 550                      void **pluglist,
 551                      int *plugcount)
 552 {
 553     OM_uint32 major, minor;
 554     size_t i, count = 0;
 555     void *plugs = NULL;
 556
 557     *pluglist = NULL;
 558     *plugcount = 0;
 559
 560     if (gs2_indicate_mechs(utils) != SASL_OK) {
 561         return SASL_NOMECH;
 562     }
 563
 564     plugs = utils->malloc(gs2_mechs->count * plugsize);
 565     if (plugs == NULL) {
 566         MEMERROR(utils);
 567         return SASL_NOMEM;
 568     }
 569     memset(plugs, 0, gs2_mechs->count * plugsize);
 570
 571     for (i = 0; i < gs2_mechs->count; i++) {
 572         gss_buffer_desc sasl_mech_name = GSS_C_EMPTY_BUFFER;
 573
 574         major = gss_inquire_saslname_for_mech(&minor,
 575                                               &gs2_mechs->elements[i],
 576                                               &sasl_mech_name,
 577                                               GSS_C_NO_BUFFER,
 578                                               GSS_C_NO_BUFFER);
 579         if (GSS_ERROR(major))
 580             continue;
 581
 582 #define PLUG_AT(index)      (void *)((unsigned char *)plugs + (count * plugsize))
 583
 584         if (plug_alloc(utils, PLUG_AT(count), &sasl_mech_name,
 585                        &gs2_mechs->elements[i]) == SASL_OK)
 586             count++;
 587
 588         gss_release_buffer(&minor, &sasl_mech_name);
 589     }
 590
 591     if (count == 0) {
 592         utils->free(plugs);
 593         return SASL_NOMECH;
 594     }
 595
 596     *pluglist = plugs;
 597     *plugcount = count;
 598
 599     return SASL_OK;
 600 }
 601
 602 static int
 603 gs2_server_plug_alloc(const sasl_utils_t *utils,
 604                       void *plug,
 605                       gss_buffer_t sasl_name,
 606                       gss_OID mech)
 607 {
 608     int ret;
 609     sasl_server_plug_t *splug = (sasl_server_plug_t *)plug;
 610     gss_buffer_desc buf;
 611
 612     memset(splug, 0, sizeof(*splug));
 613
 614     ret = gs2_get_mech_attrs(utils, mech,
 615                              &splug->security_flags,
 616                              &splug->features,
 617                              NULL);
 618     if (ret != SASL_OK)
 619         return ret;
 620
 621     ret = gs2_duplicate_buffer(utils, sasl_name, &buf);
 622     if (ret != SASL_OK)
 623         return ret;
 624
 625     splug->mech_name = (char *)buf.value;
 626     splug->glob_context = plug;
 627     splug->mech_new = gs2_server_mech_new;
 628     splug->mech_step = gs2_server_mech_step;
 629     splug->mech_dispose = gs2_common_mech_dispose;
 630     splug->mech_free = gs2_common_mech_free;
 631
 632     return SASL_OK;
 633 }
 634
 635 static sasl_server_plug_t *gs2_server_plugins;
 636 static int gs2_server_plugcount;
 637
 638 int
 639 gs2_server_plug_init(const sasl_utils_t *utils,
 640                      int maxversion,
 641                      int *outversion,
 642                      sasl_server_plug_t **pluglist,
 643                      int *plugcount)
 644 {
 645     int ret;
 646
 647     *pluglist = NULL;
 648     *plugcount = 0;
 649
 650     if (maxversion < SASL_SERVER_PLUG_VERSION)
 651         return SASL_BADVERS;
 652
 653     *outversion = SASL_SERVER_PLUG_VERSION;
 654
 655     if (gs2_server_plugins == NULL) {
 656         ret = gs2_common_plug_init(utils,
 657                                    sizeof(sasl_server_plug_t),
 658                                    gs2_server_plug_alloc,
 659                                    (void **)&gs2_server_plugins,
 660                                    &gs2_server_plugcount);
 661         if (ret != SASL_OK)
 662             return ret;
 663     }
 664
 665     *pluglist = gs2_server_plugins;
 666     *plugcount = gs2_server_plugcount;
 667
 668     return SASL_OK;
 669 }
 670
 671 /*****************************  Client Section  *****************************/
 672
 673 static int gs2_client_mech_step(void *conn_context,
 674                                 sasl_client_params_t *params,
 675                                 const char *serverin,
 676                                 unsigned serverinlen,
 677                                 sasl_interact_t **prompt_need,
 678                                 const char **clientout,
 679                                 unsigned *clientoutlen,
 680                                 sasl_out_params_t *oparams)
 681 {
 682     context_t *text = (context_t *)conn_context;
 683     gss_buffer_desc input_token = GSS_C_EMPTY_BUFFER;
 684     gss_buffer_desc output_token = GSS_C_EMPTY_BUFFER;
 685     gss_buffer_desc name_buf = GSS_C_EMPTY_BUFFER;
 686     OM_uint32 maj_stat = GSS_S_FAILURE, min_stat = 0;
 687     OM_uint32 ret_flags;
 688     int ret = SASL_FAIL;
 689     int initialContextToken;
 690
 691     *clientout = NULL;
 692     *clientoutlen = 0;
 693
 694     if (text->gss_ctx == GSS_C_NO_CONTEXT) {
 695         ret = gs2_get_init_creds(text, params, prompt_need, oparams);
 696         if (ret != SASL_OK)
 697             goto cleanup;
 698
 699         initialContextToken = 1;
 700     } else
 701         initialContextToken = 0;
 702
 703     if (text->server_name == GSS_C_NO_NAME) { /* only once */
 704         name_buf.length = strlen(params->service) + 1 + strlen(params->serverFQDN);
 705         name_buf.value = params->utils->malloc(name_buf.length + 1);
 706         if (name_buf.value == NULL) {
 707             ret = SASL_NOMEM;
 708             goto cleanup;
 709         }
 710         if (params->serverFQDN == NULL ||
 711             strlen(params->serverFQDN) == 0) {
 712             SETERROR(text->utils, "GS2 Failure: no serverFQDN");
 713             ret = SASL_FAIL;
 714             goto cleanup;
 715         }
 716
 717         snprintf(name_buf.value, name_buf.length + 1,
 718                  "%s@%s", params->service, params->serverFQDN);
 719
 720         maj_stat = gss_import_name(&min_stat,
 721                                    &name_buf,
 722                                    GSS_C_NT_HOSTBASED_SERVICE,
 723                                    &text->server_name);
 724         params->utils->free(name_buf.value);
 725         name_buf.value = NULL;
 726
 727         if (GSS_ERROR(maj_stat))
 728             goto cleanup;
 729     }
 730
 731     /* From GSSAPI plugin: apparently this is for some IMAP bug workaround */
 732     if (serverinlen == 0 && text->gss_ctx != GSS_C_NO_CONTEXT) {
 733         gss_delete_sec_context(&min_stat, &text->gss_ctx, GSS_C_NO_BUFFER);
 734         text->gss_ctx = GSS_C_NO_CONTEXT;
 735     }
 736
 737     input_token.value = (void *)serverin;
 738     input_token.length = serverinlen;
 739
 740     if (initialContextToken) {
 741         if ((text->plug.client->features & SASL_FEAT_GSS_FRAMING) == 0)
 742             text->gs2_flags |= GS2_NONSTD_FLAG;
 743
 744         switch (params->cbindingdisp) {
 745         case SASL_CB_DISP_NONE:
 746             text->gs2_flags |= GS2_CB_FLAG_N;
 747             break;
 748         case SASL_CB_DISP_USED:
 749             text->gs2_flags |= GS2_CB_FLAG_P;
 750             break;
 751         case SASL_CB_DISP_WANT:
 752             text->gs2_flags |= GS2_CB_FLAG_Y;
 753             break;
 754         }
 755
 756         ret = gs2_make_header(text, params,
 757                               strcmp(oparams->user, oparams->authid) ?
 758                                      (char *) oparams->user : NULL,
 759                               &text->out_buf, &text->out_buf_len);
 760         if (ret != 0)
 761             goto cleanup;
 762     }
 763
 764     maj_stat = gss_init_sec_context(&min_stat,
 765                                     (params->gss_creds != GSS_C_NO_CREDENTIAL)
 766                                         ? (gss_cred_id_t)params->gss_creds
 767                                         : text->client_creds,
 768                                     &text->gss_ctx,
 769                                     text->server_name,
 770                                     (gss_OID)text->mechanism,
 771                                     GSS_C_MUTUAL_FLAG,
 772                                     GSS_C_INDEFINITE,
 773                                     &text->gss_cbindings,
 774                                     serverinlen ? &input_token : GSS_C_NO_BUFFER,
 775                                     NULL,
 776                                     &output_token,
 777                                     &ret_flags,
 778                                     &text->lifetime);
 779     if (GSS_ERROR(maj_stat))
 780         goto cleanup;
 781
 782     ret = gs2_make_message(text, params, initialContextToken, &output_token,
 783                            &text->out_buf, &text->out_buf_len);
 784     if (ret != 0)
 785         goto cleanup;
 786
 787     *clientout = text->out_buf;
 788     *clientoutlen = text->out_buf_len;
 789
 790     if (maj_stat == GSS_S_CONTINUE_NEEDED) {
 791         ret = SASL_CONTINUE;
 792         goto cleanup;
 793     }
 794
 795     if (text->client_name != GSS_C_NO_NAME)
 796         gss_release_name(&min_stat, &text->client_name);
 797
 798     maj_stat = gss_inquire_context(&min_stat,
 799                                    text->gss_ctx,
 800                                    &text->client_name,
 801                                    NULL,
 802                                    &text->lifetime,
 803                                    NULL,
 804                                    &ret_flags, /* flags */
 805                                    NULL,
 806                                    NULL);
 807     if (GSS_ERROR(maj_stat))
 808         goto cleanup;
 809
 810 #if 0
 811     if ((ret_flags & GSS_C_MUTUAL_FLAG) == 0) {
 812         maj_stat = SASL_BADAUTH;
 813         goto cleanup;
 814     }
 815 #endif
 816
 817     maj_stat = gss_display_name(&min_stat,
 818                                 text->client_name,
 819                                 &name_buf,
 820                                 NULL);
 821     if (GSS_ERROR(maj_stat))
 822         goto cleanup;
 823
 824     oparams->gss_peer_name = text->server_name;
 825     oparams->gss_local_name = text->client_name;
 826     oparams->encode = NULL;
 827     oparams->decode = NULL;
 828     oparams->mech_ssf = 0;
 829     oparams->maxoutbuf = 0xFFFFFF;
 830     oparams->doneflag = 1;
 831
 832 cleanup:
 833     gss_release_buffer(&min_stat, &output_token);
 834     gss_release_buffer(&min_stat, &name_buf);
 835
 836     if (ret == SASL_OK && maj_stat != GSS_S_COMPLETE) {
 837         sasl_gs2_seterror(text->utils, maj_stat, min_stat);
 838         ret = SASL_FAIL;
 839     }
 840     if (ret < SASL_OK)
 841         sasl_gs2_free_context_contents(text);
 842
 843     return ret;
 844 }
 845
 846 static int gs2_client_mech_new(void *glob_context,
 847                                sasl_client_params_t *params,
 848                                void **conn_context)
 849 {
 850     context_t *text;
 851     int ret;
 852
 853     text = sasl_gs2_new_context(params->utils);
 854     if (text == NULL) {
 855         MEMERROR(params->utils);
 856         return SASL_NOMEM;
 857     }
 858
 859     text->gss_ctx = GSS_C_NO_CONTEXT;
 860     text->client_name = GSS_C_NO_NAME;
 861     text->server_creds = GSS_C_NO_CREDENTIAL;
 862     text->client_creds  = GSS_C_NO_CREDENTIAL;
 863     text->plug.client = glob_context;
 864
 865     ret = gs2_map_sasl_name(params->utils, text->plug.client->mech_name,
 866                             &text->mechanism);
 867     if (ret != SASL_OK) {
 868         gs2_common_mech_dispose(text, params->utils);
 869         return ret;
 870     }
 871
 872     *conn_context = text;
 873
 874     return SASL_OK;
 875 }
 876
 877 static int
 878 gs2_client_plug_alloc(const sasl_utils_t *utils,
 879                       void *plug,
 880                       gss_buffer_t sasl_name,
 881                       gss_OID mech)
 882 {
 883     int ret;
 884     sasl_client_plug_t *cplug = (sasl_client_plug_t *)plug;
 885     gss_buffer_desc buf;
 886
 887     memset(cplug, 0, sizeof(*cplug));
 888
 889     ret = gs2_get_mech_attrs(utils, mech,
 890                              &cplug->security_flags,
 891                              &cplug->features,
 892                              &cplug->required_prompts);
 893     if (ret != SASL_OK)
 894         return ret;
 895
 896     ret = gs2_duplicate_buffer(utils, sasl_name, &buf);
 897     if (ret != SASL_OK)
 898         return ret;
 899
 900     cplug->mech_name = (char *)buf.value;
 901     cplug->features |= SASL_FEAT_NEEDSERVERFQDN;
 902     cplug->glob_context = plug;
 903     cplug->mech_new = gs2_client_mech_new;
 904     cplug->mech_step = gs2_client_mech_step;
 905     cplug->mech_dispose = gs2_common_mech_dispose;
 906     cplug->mech_free = gs2_common_mech_free;
 907
 908     return SASL_OK;
 909 }
 910
 911 static sasl_client_plug_t *gs2_client_plugins;
 912 static int gs2_client_plugcount;
 913
 914 int
 915 gs2_client_plug_init(const sasl_utils_t *utils,
 916                      int maxversion,
 917                      int *outversion,
 918                      sasl_client_plug_t **pluglist,
 919                      int *plugcount)
 920 {
 921     int ret;
 922
 923     *pluglist = NULL;
 924     *plugcount = 0;
 925
 926     if (maxversion < SASL_CLIENT_PLUG_VERSION)
 927         return SASL_BADVERS;
 928
 929     *outversion = SASL_CLIENT_PLUG_VERSION;
 930
 931     if (gs2_client_plugins == NULL) {
 932         ret = gs2_common_plug_init(utils,
 933                                    sizeof(sasl_client_plug_t),
 934                                    gs2_client_plug_alloc,
 935                                    (void **)&gs2_client_plugins,
 936                                    &gs2_client_plugcount);
 937         if (ret != SASL_OK)
 938             return ret;
 939     }
 940
 941     *pluglist = gs2_client_plugins;
 942     *plugcount = gs2_client_plugcount;
 943
 944     return SASL_OK;
 945 }
 946
 947 /*
 948  * Copy header and application channel bindings to GSS channel bindings
 949  * structure in context.
 950  */
 951 static int
 952 gs2_save_cbindings(context_t *text,
 953                    gss_buffer_t header,
 954                    const sasl_channel_binding_t *cbinding)
 955 {
 956     gss_buffer_t gss_cbindings = &text->gss_cbindings.application_data;
 957     size_t len;
 958     unsigned char *p;
 959
 960     assert(gss_cbindings->value == NULL);
 961
 962     /*
 963      * The application-data field MUST be set to the gs2-header, excluding
 964      * the initial [gs2-nonstd-flag ","] part, concatenated with, when a
 965      * gs2-cb-flag of "p" is used, the application's channel binding data.
 966      */
 967     len = header->length;
 968     if (text->gs2_flags & GS2_NONSTD_FLAG) {
 969         assert(len > 2);
 970         len -= 2;
 971     }
 972     if ((text->gs2_flags & GS2_CB_FLAG_MASK) == GS2_CB_FLAG_P &&
 973         cbinding != NULL) {
 974         len += cbinding->len;
 975     }
 976
 977     gss_cbindings->length = len;
 978     gss_cbindings->value = text->utils->malloc(len);
 979     if (gss_cbindings->value == NULL)
 980         return SASL_NOMEM;
 981
 982     p = (unsigned char *)gss_cbindings->value;
 983     if (text->gs2_flags & GS2_NONSTD_FLAG) {
 984         memcpy(p, (unsigned char *)header->value + 2, header->length - 2);
 985         p += header->length - 2;
 986     } else {
 987         memcpy(p, header->value, header->length);
 988         p += header->length;
 989     }
 990
 991     if ((text->gs2_flags & GS2_CB_FLAG_MASK) == GS2_CB_FLAG_P &&
 992         cbinding != NULL) {
 993         memcpy(p, cbinding->data, cbinding->len);
 994     }
 995
 996     return SASL_OK;
 997 }
 998
 999 #define CHECK_REMAIN(n)     do { if (remain < (n)) return SASL_BADPROT; } while (0)
1000
1001 /*
1002  * Verify gs2-header, save authzid and channel bindings to context.
1003  */
1004 static int
1005 gs2_verify_initial_message(context_t *text,
1006                            sasl_server_params_t *sparams,
1007                            const char *in,
1008                            unsigned inlen,
1009                            gss_buffer_t token)
1010 {
1011     OM_uint32 major, minor;
1012     char *p = (char *)in;
1013     unsigned remain = inlen;
1014     int ret;
1015     gss_buffer_desc buf = GSS_C_EMPTY_BUFFER;
1016
1017     assert(text->cbindingname == NULL);
1018     assert(text->authzid == NULL);
1019
1020     token->length = 0;
1021     token->value = NULL;
1022
1023     /* minimum header includes CB flag and non-zero GSS token */
1024     CHECK_REMAIN(4); /* [pny],,. */
1025
1026     /* non-standard GSS framing flag */
1027     if (remain > 1 && memcmp(p, "F,", 2) == 0) {
1028         text->gs2_flags |= GS2_NONSTD_FLAG;
1029         remain -= 2;
1030         p += 2;
1031     }
1032
1033     /* SASL channel bindings */
1034     CHECK_REMAIN(1); /* [pny] */
1035     remain--;
1036     switch (*p++) {
1037     case 'p':
1038         CHECK_REMAIN(1); /* = */
1039         remain--;
1040         if (*p++ != '=')
1041             return SASL_BADPROT;
1042
1043         ret = gs2_unescape_authzid(text->utils, &p, &remain, &text->cbindingname);
1044         if (ret != SASL_OK)
1045             return ret;
1046
1047         text->gs2_flags |= GS2_CB_FLAG_P;
1048         break;
1049     case 'n':
1050         text->gs2_flags |= GS2_CB_FLAG_N;
1051         break;
1052     case 'y':
1053         text->gs2_flags |= GS2_CB_FLAG_Y;
1054         break;
1055     }
1056
1057     CHECK_REMAIN(1); /* , */
1058     remain--;
1059     if (*p++ != ',')
1060         return SASL_BADPROT;
1061
1062     /* authorization identity */
1063     if (remain > 1 && memcmp(p, "a=", 2) == 0) {
1064         CHECK_REMAIN(2);
1065         remain -= 2;
1066         p += 2;
1067
1068         ret = gs2_unescape_authzid(text->utils, &p, &remain, &text->authzid);
1069         if (ret != SASL_OK)
1070             return ret;
1071     }
1072
1073     /* end of header */
1074     CHECK_REMAIN(1); /* , */
1075     remain--;
1076     if (*p++ != ',')
1077         return SASL_BADPROT;
1078
1079     buf.length = inlen - remain;
1080     buf.value = (void *)in;
1081
1082     /* stash channel bindings to pass into gss_accept_sec_context() */
1083     ret = gs2_save_cbindings(text, &buf, sparams->cbinding);
1084     if (ret != SASL_OK)
1085         return ret;
1086
1087     if (text->gs2_flags & GS2_NONSTD_FLAG) {
1088         buf.length = remain;
1089         buf.value = p;
1090     } else {
1091         gss_buffer_desc tmp;
1092
1093         tmp.length = remain;
1094         tmp.value = p;
1095
1096         major = gss_encapsulate_token(&tmp, text->mechanism, &buf);
1097         if (GSS_ERROR(major))
1098             return SASL_NOMEM;
1099     }
1100
1101     token->value = text->utils->malloc(buf.length);
1102     if (token->value == NULL)
1103         return SASL_NOMEM;
1104
1105     token->length = buf.length;
1106     memcpy(token->value, buf.value, buf.length);
1107
1108     if ((text->gs2_flags & GS2_NONSTD_FLAG) == 0)
1109         gss_release_buffer(&minor, &buf);
1110
1111     return SASL_OK;
1112 }
1113
1114 /*
1115  * Create gs2-header, save channel bindings to context.
1116  */
1117 static int
1118 gs2_make_header(context_t *text,
1119                 sasl_client_params_t *cparams,
1120                 const char *authzid,
1121                 char **out,
1122                 unsigned *outlen)
1123 {
1124     size_t required = 0;
1125     size_t wire_authzid_len = 0, cbnamelen = 0;
1126     char *wire_authzid = NULL;
1127     char *p;
1128     int ret;
1129     gss_buffer_desc buf;
1130
1131     *out = NULL;
1132     *outlen = 0;
1133
1134     /* non-standard GSS framing flag */
1135     if (text->gs2_flags & GS2_NONSTD_FLAG)
1136         required += 2; /* F, */
1137
1138     /* SASL channel bindings */
1139     switch (text->gs2_flags & GS2_CB_FLAG_MASK) {
1140     case GS2_CB_FLAG_P:
1141         if (!SASL_CB_PRESENT(cparams))
1142             return SASL_BADPARAM;
1143         cbnamelen = strlen(cparams->cbinding->name);
1144         required += 1 /*=*/ + cbnamelen;
1145         /* fallthrough */
1146     case GS2_CB_FLAG_N:
1147     case GS2_CB_FLAG_Y:
1148         required += 2; /* [pny], */
1149         break;
1150     default:
1151         return SASL_BADPARAM;
1152     }
1153
1154     /* authorization identity */
1155     if (authzid != NULL) {
1156         ret = gs2_escape_authzid(text->utils, authzid,
1157                                  strlen(authzid), &wire_authzid);
1158         if (ret != SASL_OK)
1159             return ret;
1160
1161         wire_authzid_len = strlen(wire_authzid);
1162         required += 2 /* a= */ + wire_authzid_len;
1163     }
1164
1165     required += 1; /* trailing comma */
1166
1167     ret = _plug_buf_alloc(text->utils, out, outlen, required);
1168     if (ret != SASL_OK) {
1169         text->utils->free(wire_authzid);
1170         return ret;
1171     }
1172
1173     *out = text->out_buf;
1174     *outlen = required;
1175
1176     p = (char *)text->out_buf;
1177     if (text->gs2_flags & GS2_NONSTD_FLAG) {
1178         *p++ = 'F';
1179         *p++ = ',';
1180     }
1181     switch (text->gs2_flags & GS2_CB_FLAG_MASK) {
1182     case GS2_CB_FLAG_P:
1183         memcpy(p, "p=", 2);
1184         memcpy(p + 2, cparams->cbinding->name, cbnamelen);
1185         p += 2 + cbnamelen;
1186         break;
1187     case GS2_CB_FLAG_N:
1188         *p++ = 'n';
1189         break;
1190     case GS2_CB_FLAG_Y:
1191         *p++ = 'y';
1192         break;
1193     }
1194     *p++ = ',';
1195     if (wire_authzid != NULL) {
1196         memcpy(p, "a=", 2);
1197         memcpy(p + 2, wire_authzid, wire_authzid_len);
1198         text->utils->free(wire_authzid);
1199         p += 2 + wire_authzid_len;
1200     }
1201     *p++ = ',';
1202
1203     assert(p == (char *)text->out_buf + required);
1204
1205     buf.length = required;
1206     buf.value = *out;
1207
1208     ret = gs2_save_cbindings(text, &buf, cparams->cbinding);
1209     if (ret != SASL_OK)
1210         return ret;
1211
1212     return SASL_OK;
1213 }
1214
1215 /*
1216  * Convert a GSS token to a GS2 one
1217  */
1218 static int
1219 gs2_make_message(context_t *text,
1220                  sasl_client_params_t *cparams __attribute__((unused)),
1221                  int initialContextToken,
1222                  gss_buffer_t token,
1223                  char **out,
1224                  unsigned *outlen)
1225 {
1226     OM_uint32 major, minor;
1227     int ret;
1228     unsigned header_len = 0;
1229     gss_buffer_desc decap_token = GSS_C_EMPTY_BUFFER;
1230
1231     if (initialContextToken) {
1232         header_len = *outlen;
1233
1234         major = gss_decapsulate_token(token, text->mechanism, &decap_token);
1235         if ((major == GSS_S_DEFECTIVE_TOKEN &&
1236              (text->plug.client->features & SASL_FEAT_GSS_FRAMING)) ||
1237             GSS_ERROR(major))
1238             return SASL_FAIL;
1239
1240         token = &decap_token;
1241     }
1242
1243     ret = _plug_buf_alloc(text->utils, out, outlen,
1244                           header_len + token->length);
1245     if (ret != 0)
1246         return ret;
1247
1248     memcpy(*out + header_len, token->value, token->length);
1249     *outlen = header_len + token->length;
1250
1251     if (initialContextToken)
1252         gss_release_buffer(&minor, &decap_token);
1253
1254     return SASL_OK;
1255 }
1256
1257 static const unsigned long gs2_required_prompts[] = {
1258     SASL_CB_LIST_END
1259 };
1260
1261 /*
1262  * Map GSS mechanism attributes to SASL ones
1263  */
1264 static int
1265 gs2_get_mech_attrs(const sasl_utils_t *utils,
1266                    const gss_OID mech,
1267                    unsigned int *security_flags,
1268                    unsigned int *features,
1269                    const unsigned long **prompts)
1270 {
1271     OM_uint32 major, minor;
1272     int present;
1273     gss_OID_set attrs = GSS_C_NO_OID_SET;
1274
1275     major = gss_inquire_attrs_for_mech(&minor, mech, &attrs, NULL);
1276     if (GSS_ERROR(major)) {
1277         utils->seterror(utils->conn, SASL_NOLOG,
1278                         "GS2 Failure: gss_inquire_attrs_for_mech");
1279         return SASL_FAIL;
1280     }
1281
1282     *security_flags = SASL_SEC_NOPLAINTEXT | SASL_SEC_NOACTIVE;
1283     *features = SASL_FEAT_WANT_CLIENT_FIRST | SASL_FEAT_CHANNEL_BINDING;
1284     if (prompts != NULL)
1285         *prompts = gs2_required_prompts;
1286
1287 #define MA_PRESENT(a)   (gss_test_oid_set_member(&minor, (gss_OID)(a), \
1288                                                  attrs, &present) == GSS_S_COMPLETE && \
1289                          present)
1290
1291     if (MA_PRESENT(GSS_C_MA_PFS))
1292         *security_flags |= SASL_SEC_FORWARD_SECRECY;
1293     if (!MA_PRESENT(GSS_C_MA_AUTH_INIT_ANON))
1294         *security_flags |= SASL_SEC_NOANONYMOUS;
1295     if (MA_PRESENT(GSS_C_MA_DELEG_CRED))
1296         *security_flags |= SASL_SEC_PASS_CREDENTIALS;
1297     if (MA_PRESENT(GSS_C_MA_AUTH_TARG))
1298         *security_flags |= SASL_SEC_MUTUAL_AUTH;
1299     if (MA_PRESENT(GSS_C_MA_AUTH_INIT_INIT) && prompts != NULL)
1300         *prompts = NULL;
1301     if (MA_PRESENT(GSS_C_MA_ITOK_FRAMED))
1302         *features |= SASL_FEAT_GSS_FRAMING;
1303
1304     gss_release_oid_set(&minor, &attrs);
1305
1306     return SASL_OK;
1307 }
1308
1309 /*
1310  * Enumerate GSS mechanisms that can be used for GS2
1311  */
1312 static int gs2_indicate_mechs(const sasl_utils_t *utils)
1313 {
1314     OM_uint32 major, minor;
1315     gss_OID_desc desired_oids[2];
1316     gss_OID_set_desc desired_attrs;
1317     gss_OID_desc except_oids[3];
1318     gss_OID_set_desc except_attrs;
1319
1320     if (gs2_mechs != GSS_C_NO_OID_SET)
1321         return SASL_OK;
1322
1323     desired_oids[0] = *GSS_C_MA_AUTH_INIT;
1324     desired_oids[1] = *GSS_C_MA_CBINDINGS;
1325     desired_attrs.count = sizeof(desired_oids)/sizeof(desired_oids[0]);
1326     desired_attrs.elements = desired_oids;
1327
1328     except_oids[0] = *GSS_C_MA_MECH_NEGO;
1329     except_oids[1] = *GSS_C_MA_NOT_MECH;
1330     except_oids[2] = *GSS_C_MA_DEPRECATED;
1331
1332     except_attrs.count = sizeof(except_oids)/sizeof(except_oids[0]);
1333     except_attrs.elements = except_oids;
1334
1335     major = gss_indicate_mechs_by_attrs(&minor,
1336                                         &desired_attrs,
1337                                         &except_attrs,
1338                                         GSS_C_NO_OID_SET,
1339                                         &gs2_mechs);
1340     if (GSS_ERROR(major)) {
1341         utils->seterror(utils->conn, SASL_NOLOG,
1342                         "GS2 Failure: gss_indicate_mechs_by_attrs");
1343         return SASL_FAIL;
1344     }
1345
1346     return (gs2_mechs->count > 0) ? SASL_OK : SASL_NOMECH;
1347 }
1348
1349 /*
1350  * Map SASL mechanism name to OID
1351  */
1352 static int
1353 gs2_map_sasl_name(const sasl_utils_t *utils,
1354                   const char *mech,
1355                   gss_OID *oid)
1356 {
1357     OM_uint32 major, minor;
1358     gss_buffer_desc buf;
1359
1360     buf.length = strlen(mech);
1361     buf.value = (void *)mech;
1362
1363     major = gss_inquire_mech_for_saslname(&minor, &buf, oid);
1364     if (GSS_ERROR(major)) {
1365         utils->seterror(utils->conn, SASL_NOLOG,
1366                         "GS2 Failure: gss_inquire_mech_for_saslname");
1367         return SASL_FAIL;
1368     }
1369
1370     return SASL_OK;
1371 }
1372
1373 static int
1374 gs2_duplicate_buffer(const sasl_utils_t *utils,
1375                      const gss_buffer_t src,
1376                      gss_buffer_t dst)
1377 {
1378     dst->value = utils->malloc(src->length + 1);
1379     if (dst->value == NULL)
1380         return SASL_NOMEM;
1381
1382     memcpy(dst->value, src->value, src->length);
1383     ((char *)dst->value)[src->length] = '\0';
1384     dst->length = src->length;
1385
1386     return SASL_OK;
1387 }
1388
1389 static int
1390 gs2_unescape_authzid(const sasl_utils_t *utils,
1391                      char **endp,
1392                      unsigned *remain,
1393                      char **authzid)
1394 {
1395     char *in = *endp;
1396     size_t i, len, inlen = *remain;
1397     char *p;
1398
1399     *endp = NULL;
1400
1401     for (i = 0, len = 0; i < inlen; i++) {
1402         if (in[i] == ',') {
1403             *endp = &in[i];
1404             *remain -= i;
1405             break;
1406         } else if (in[i] == '=') {
1407             if (inlen <= i + 2)
1408                 return SASL_BADPROT;
1409             i += 2;
1410         }
1411         len++;
1412     }
1413
1414     if (len == 0 || *endp == NULL)
1415         return SASL_BADPROT;
1416
1417     p = *authzid = utils->malloc(len + 1);
1418     if (*authzid == NULL)
1419         return SASL_NOMEM;
1420
1421     for (i = 0; i < inlen; i++) {
1422         if (in[i] == ',')
1423             break;
1424         else if (in[i] == '=') {
1425             if (memcmp(&in[i + 1], "2C", 2) == 0)
1426                 *p++ = ',';
1427             else if (memcmp(&in[i + 1], "3D", 2) == 0)
1428                 *p++ = '=';
1429             else {
1430                 utils->free(*authzid);
1431                 *authzid = NULL;
1432                 return SASL_BADPROT;
1433             }
1434             i += 2;
1435         } else
1436             *p++ = in[i];
1437     }
1438
1439     *p = '\0';
1440
1441     return SASL_OK;
1442 }
1443
1444 static int
1445 gs2_escape_authzid(const sasl_utils_t *utils,
1446                    const char *in,
1447                    unsigned inlen,
1448                    char **authzid)
1449 {
1450     size_t i;
1451     char *p;
1452
1453     p = *authzid = utils->malloc((inlen * 3) + 1);
1454     if (*authzid == NULL)
1455         return SASL_NOMEM;
1456
1457     for (i = 0; i < inlen; i++) {
1458         if (in[i] == ',') {
1459             memcpy(p, "=2C", 3);
1460             p += 3;
1461         } else if (in[i] == '=') {
1462             memcpy(p, "=3D", 3);
1463             p += 3;
1464         } else {
1465             *p++ = in[i];
1466         }
1467     }
1468
1469     *p = '\0';
1470
1471     return SASL_OK;
1472 }
1473
1474 #define GOT_CREDS(text, params) ((text)->client_creds != NULL || (params)->gss_creds != NULL)
1475 #define CRED_ERROR(status)      ((status) == GSS_S_CRED_UNAVAIL || (status) == GSS_S_NO_CRED)
1476
1477 /*
1478  * Determine the authentication identity from the application supplied
1479  * GSS credential, the application supplied identity, and the default
1480  * GSS credential, in that order. Then, acquire credentials.
1481  */
1482 static int
1483 gs2_get_init_creds(context_t *text,
1484                    sasl_client_params_t *params,
1485                    sasl_interact_t **prompt_need,
1486                    sasl_out_params_t *oparams)
1487 {
1488     int result = SASL_OK;
1489     const char *authid = NULL, *userid = NULL;
1490     int user_result = SASL_OK;
1491     int auth_result = SASL_OK;
1492     int pass_result = SASL_OK;
1493     OM_uint32 maj_stat = GSS_S_COMPLETE, min_stat = 0;
1494     gss_OID_set_desc mechs;
1495     gss_buffer_desc cred_authid = GSS_C_EMPTY_BUFFER;
1496     gss_buffer_desc name_buf = GSS_C_EMPTY_BUFFER;
1497
1498     mechs.count = 1;
1499     mechs.elements = (gss_OID)text->mechanism;
1500
1501     /*
1502      * Get the authentication identity from the application.
1503      */
1504     if (oparams->authid == NULL) {
1505         auth_result = _plug_get_authid(params->utils, &authid, prompt_need);
1506         if (auth_result != SASL_OK && auth_result != SASL_INTERACT) {
1507             result = auth_result;
1508             goto cleanup;
1509         }
1510     }
1511
1512     /*
1513      * Get the authorization identity from the application.
1514      */
1515     if (oparams->user == NULL) {
1516         user_result = _plug_get_userid(params->utils, &userid, prompt_need);
1517         if (user_result != SASL_OK && user_result != SASL_INTERACT) {
1518             result = user_result;
1519             goto cleanup;
1520         }
1521     }
1522
1523     /*
1524      * Canonicalize the authentication and authorization identities before
1525      * calling GSS_Import_name.
1526      */
1527     if (auth_result == SASL_OK && user_result == SASL_OK &&
1528         oparams->authid == NULL) {
1529         if (userid == NULL || userid[0] == '\0') {
1530             result = params->canon_user(params->utils->conn, authid, 0,
1531                                         SASL_CU_AUTHID | SASL_CU_AUTHZID,
1532                                         oparams);
1533         } else {
1534             result = params->canon_user(params->utils->conn,
1535                                         authid, 0, SASL_CU_AUTHID, oparams);
1536             if (result != SASL_OK)
1537                 goto cleanup;
1538
1539             result = params->canon_user(params->utils->conn,
1540                                         userid, 0, SASL_CU_AUTHZID, oparams);
1541             if (result != SASL_OK)
1542                 goto cleanup;
1543         }
1544
1545         if (oparams->authid != NULL) {
1546             name_buf.length = strlen(oparams->authid);
1547             name_buf.value = (void *)oparams->authid;
1548
1549             assert(text->client_name == GSS_C_NO_NAME);
1550
1551             maj_stat = gss_import_name(&min_stat,
1552                                        &name_buf,
1553                                        GSS_C_NT_USER_NAME,
1554                                        &text->client_name);
1555             if (GSS_ERROR(maj_stat))
1556                 goto cleanup;
1557
1558             /* The authid may have changed after prompting, so free any creds */
1559             gss_release_cred(&min_stat, &text->client_creds);
1560         }
1561     }
1562
1563     /*
1564      * If application didn't provide an authid, then use the default
1565      * credential. If that doesn't work, give up.
1566      */
1567     if (!GOT_CREDS(text, params) && oparams->authid == NULL) {
1568         maj_stat = gss_acquire_cred(&min_stat,
1569                                     GSS_C_NO_NAME,
1570                                     GSS_C_INDEFINITE,
1571                                     &mechs,
1572                                     GSS_C_INITIATE,
1573                                     &text->client_creds,
1574                                     NULL,
1575                                     &text->lifetime);
1576         if (GSS_ERROR(maj_stat))
1577             goto cleanup;
1578
1579         assert(text->client_name == GSS_C_NO_NAME);
1580
1581         maj_stat = gss_inquire_cred(&min_stat,
1582                                     params->gss_creds
1583                                         ? (gss_cred_id_t)params->gss_creds
1584                                         : text->client_creds,
1585                                     &text->client_name,
1586                                     NULL,
1587                                     NULL,
1588                                     NULL);
1589         if (GSS_ERROR(maj_stat)) {
1590             /* Maybe there was no default credential */
1591             auth_result = SASL_INTERACT;
1592             goto interact;
1593         }
1594
1595         maj_stat = gss_display_name(&min_stat,
1596                                     text->client_name,
1597                                     &cred_authid,
1598                                     NULL);
1599         if (GSS_ERROR(maj_stat))
1600             goto cleanup;
1601
1602         if (userid == NULL || userid[0] == '\0') {
1603             result = params->canon_user(params->utils->conn,
1604                                         cred_authid.value, cred_authid.length,
1605                                         SASL_CU_AUTHID | SASL_CU_AUTHZID,
1606                                         oparams);
1607         } else {
1608             result = params->canon_user(params->utils->conn,
1609                                         cred_authid.value, cred_authid.length,
1610                                         SASL_CU_AUTHID, oparams);
1611             if (result != SASL_OK)
1612                 goto cleanup;
1613
1614             result = params->canon_user(params->utils->conn,
1615                                         cred_authid.value, cred_authid.length,
1616                                         SASL_CU_AUTHZID, oparams);
1617             if (result != SASL_OK)
1618                 goto cleanup;
1619         }
1620     }
1621
1622     /*
1623      * Armed with the authentication identity, try to get a credential without
1624      * a password.
1625      */
1626     if (!GOT_CREDS(text, params) && text->client_name != GSS_C_NO_NAME) {
1627         maj_stat = gss_acquire_cred(&min_stat,
1628                                     text->client_name,
1629                                     GSS_C_INDEFINITE,
1630                                     &mechs,
1631                                     GSS_C_INITIATE,
1632                                     &text->client_creds,
1633                                     NULL,
1634                                     &text->lifetime);
1635         if (GSS_ERROR(maj_stat) && !CRED_ERROR(maj_stat))
1636             goto cleanup;
1637     }
1638
1639     /*
1640      * If that failed, try to get a credential with a password.
1641      */
1642     if (!GOT_CREDS(text, params)) {
1643         if (text->password == NULL) {
1644             pass_result = _plug_get_password(params->utils, &text->password,
1645                                              &text->free_password, prompt_need);
1646             if (pass_result != SASL_OK && pass_result != SASL_INTERACT) {
1647                 result = pass_result;
1648                 goto cleanup;
1649             }
1650         }
1651
1652         if (text->password != NULL) {
1653             gss_buffer_desc password_buf;
1654
1655             password_buf.length = text->password->len;
1656             password_buf.value = text->password->data;
1657
1658             maj_stat = gss_acquire_cred_with_password(&min_stat,
1659                                                       text->client_name,
1660                                                       &password_buf,
1661                                                       GSS_C_INDEFINITE,
1662                                                       &mechs,
1663                                                       GSS_C_INITIATE,
1664                                                       &text->client_creds,
1665                                                       NULL,
1666                                                       &text->lifetime);
1667             if (GSS_ERROR(maj_stat))
1668                 goto cleanup;
1669         }
1670     }
1671
1672     maj_stat = GSS_S_COMPLETE;
1673
1674 interact:
1675
1676     /* free prompts we got */
1677     if (prompt_need && *prompt_need) {
1678         params->utils->free(*prompt_need);
1679         *prompt_need = NULL;
1680     }
1681
1682     /* if there are prompts not filled in */
1683     if (user_result == SASL_INTERACT || auth_result == SASL_INTERACT ||
1684         pass_result == SASL_INTERACT) {
1685         /* make the prompt list */
1686         result =
1687             _plug_make_prompts(params->utils, prompt_need,
1688                                user_result == SASL_INTERACT ?
1689                                "Please enter your authorization name" : NULL,
1690                                NULL,
1691                                auth_result == SASL_INTERACT ?
1692                                "Please enter your authentication name" : NULL,
1693                                NULL,
1694                                pass_result == SASL_INTERACT ?
1695                                "Please enter your password" : NULL, NULL,
1696                                NULL, NULL, NULL,
1697                                NULL,
1698                                NULL, NULL);
1699         if (result == SASL_OK)
1700             result = SASL_INTERACT;
1701     }
1702
1703 cleanup:
1704     if (result == SASL_OK && maj_stat != GSS_S_COMPLETE) {
1705         sasl_gs2_seterror(text->utils, maj_stat, min_stat);
1706         result = SASL_FAIL;
1707     }
1708
1709     gss_release_buffer(&min_stat, &cred_authid);
1710
1711     return result;
1712 }
1713
1714 static int
1715 sasl_gs2_seterror_(const sasl_utils_t *utils, OM_uint32 maj, OM_uint32 min,
1716                    int logonly)
1717 {
1718     OM_uint32 maj_stat, min_stat;
1719     gss_buffer_desc msg;
1720     OM_uint32 msg_ctx;
1721     int ret;
1722     char *out = NULL;
1723     unsigned int len, curlen = 0;
1724     const char prefix[] = "GS2 Error: ";
1725
1726     len = sizeof(prefix);
1727     ret = _plug_buf_alloc(utils, &out, &curlen, 256);
1728     if (ret != SASL_OK)
1729         return SASL_OK;
1730
1731     strcpy(out, prefix);
1732
1733     msg_ctx = 0;
1734     while (1) {
1735         maj_stat = gss_display_status(&min_stat, maj,
1736                                       GSS_C_GSS_CODE, GSS_C_NULL_OID,
1737                                       &msg_ctx, &msg);
1738
1739         if (GSS_ERROR(maj_stat)) {
1740             if (logonly) {
1741                 utils->log(utils->conn, SASL_LOG_FAIL,
1742                         "GS2 Failure: (could not get major error message)");
1743             } else {
1744                 utils->seterror(utils->conn, 0,
1745                                 "GS2 Failure "
1746                                 "(could not get major error message)");
1747             }
1748             utils->free(out);
1749             return SASL_OK;
1750         }
1751
1752         len += len + msg.length;
1753         ret = _plug_buf_alloc(utils, &out, &curlen, len);
1754         if (ret != SASL_OK) {
1755             utils->free(out);
1756             return SASL_OK;
1757         }
1758
1759         strcat(out, msg.value);
1760
1761         gss_release_buffer(&min_stat, &msg);
1762
1763         if (!msg_ctx)
1764             break;
1765     }
1766
1767     /* Now get the minor status */
1768
1769     len += 2;
1770     ret = _plug_buf_alloc(utils, &out, &curlen, len);
1771     if (ret != SASL_OK) {
1772         utils->free(out);
1773         return SASL_NOMEM;
1774     }
1775
1776     strcat(out, " (");
1777
1778     msg_ctx = 0;
1779     while (1) {
1780         maj_stat = gss_display_status(&min_stat, min,
1781                                       GSS_C_MECH_CODE, GSS_C_NULL_OID,
1782                                       &msg_ctx, &msg);
1783
1784         if (GSS_ERROR(maj_stat)) {
1785             if (logonly) {
1786                 utils->log(utils->conn, SASL_LOG_FAIL,
1787                         "GS2 Failure: (could not get minor error message)");
1788             } else {
1789                 utils->seterror(utils->conn, 0,
1790                                 "GS2 Failure "
1791                                 "(could not get minor error message)");
1792             }
1793             utils->free(out);
1794             return SASL_OK;
1795         }
1796
1797         len += len + msg.length;
1798
1799         ret = _plug_buf_alloc(utils, &out, &curlen, len);
1800         if (ret != SASL_OK) {
1801             utils->free(out);
1802             return SASL_NOMEM;
1803         }
1804
1805         strcat(out, msg.value);
1806
1807         gss_release_buffer(&min_stat, &msg);
1808
1809         if (!msg_ctx)
1810             break;
1811     }
1812
1813     len += 1;
1814     ret = _plug_buf_alloc(utils, &out, &curlen, len);
1815     if (ret != SASL_OK) {
1816         utils->free(out);
1817         return SASL_NOMEM;
1818     }
1819
1820     strcat(out, ")");
1821
1822     if (logonly) {
1823         utils->log(utils->conn, SASL_LOG_FAIL, out);
1824     } else {
1825         utils->seterror(utils->conn, 0, out);
1826     }
1827     utils->free(out);
1828
1829     return SASL_OK;
1830 }