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     if ((out_flags & GSS_C_SEQUENCE_FLAG) == 0)  {
 444         ret = SASL_BADAUTH;
 445         goto cleanup;
 446     }
 447
 448     maj_stat = gss_display_name(&min_stat, text->client_name,
 449                                 &name_buf, NULL);
 450     if (GSS_ERROR(maj_stat))
 451         goto cleanup;
 452
 453     ret = gs2_duplicate_buffer(params->utils, &name_buf, &short_name_buf);
 454     if (ret != 0)
 455         goto cleanup;
 456
 457     p = (char *)memchr(name_buf.value, '@', name_buf.length);
 458     if (p != NULL) {
 459         short_name_buf.length = (p - (char *)name_buf.value);
 460
 461         maj_stat = gss_import_name(&min_stat,
 462                                    &short_name_buf,
 463                                    GSS_C_NT_USER_NAME,
 464                                    &without);
 465         if (GSS_ERROR(maj_stat)) {
 466             ret = SASL_FAIL;
 467             goto cleanup;
 468         }
 469
 470         maj_stat = gss_compare_name(&min_stat, text->client_name,
 471                                     without, &equal);
 472         if (GSS_ERROR(maj_stat)) {
 473             ret = SASL_FAIL;
 474             goto cleanup;
 475         }
 476
 477         if (equal)
 478             ((char *)short_name_buf.value)[short_name_buf.length] = '\0';
 479     }
 480
 481     text->authid = (char *)short_name_buf.value;
 482     short_name_buf.value = NULL;
 483     short_name_buf.length = 0;
 484
 485     if (text->authzid != NULL) {
 486         ret = params->canon_user(params->utils->conn,
 487                                  text->authzid, 0,
 488                                  SASL_CU_AUTHZID, oparams);
 489         if (ret != SASL_OK)
 490             goto cleanup;
 491     }
 492
 493     ret = params->canon_user(params->utils->conn,
 494                              text->authid, 0,
 495                              text->authzid == NULL
 496                                 ? (SASL_CU_AUTHZID | SASL_CU_AUTHID)
 497                                 : SASL_CU_AUTHID,
 498                              oparams);
 499     if (ret != SASL_OK)
 500         goto cleanup;
 501
 502     switch (text->gs2_flags & GS2_CB_FLAG_MASK) {
 503     case GS2_CB_FLAG_N:
 504         oparams->cbindingdisp = SASL_CB_DISP_NONE;
 505         break;
 506     case GS2_CB_FLAG_P:
 507         oparams->cbindingdisp = SASL_CB_DISP_USED;
 508         oparams->cbindingname = text->cbindingname;
 509         break;
 510     case GS2_CB_FLAG_Y:
 511         oparams->cbindingdisp = SASL_CB_DISP_WANT;
 512         break;
 513     }
 514
 515     if (text->client_creds != GSS_C_NO_CREDENTIAL)
 516         oparams->client_creds = &text->client_creds;
 517     else
 518         oparams->client_creds = NULL;
 519
 520     oparams->gss_peer_name = text->client_name;
 521     oparams->gss_local_name = text->server_name;
 522     oparams->maxoutbuf = 0xFFFFFF;
 523     oparams->encode = NULL;
 524     oparams->decode = NULL;
 525     oparams->mech_ssf = 0;
 526     oparams->doneflag = 1;
 527
 528     ret = SASL_OK;
 529
 530 cleanup:
 531     if (initialContextToken)
 532         gss_release_buffer(&min_stat, &input_token);
 533     gss_release_buffer(&min_stat, &name_buf);
 534     gss_release_buffer(&min_stat, &short_name_buf);
 535     gss_release_buffer(&min_stat, &output_token);
 536     gss_release_name(&min_stat, &without);
 537
 538     if (ret == SASL_OK && maj_stat != GSS_S_COMPLETE) {
 539         sasl_gs2_seterror(text->utils, maj_stat, min_stat);
 540         ret = SASL_FAIL;
 541     }
 542     if (ret != SASL_OK && ret != SASL_CONTINUE)
 543         sasl_gs2_free_context_contents(text);
 544
 545     return ret;
 546 }
 547
 548 static int
 549 gs2_common_plug_init(const sasl_utils_t *utils,
 550                      size_t plugsize,
 551                      int (*plug_alloc)(const sasl_utils_t *,
 552                                        void *,
 553                                        const gss_buffer_t,
 554                                        const gss_OID),
 555                      void **pluglist,
 556                      int *plugcount)
 557 {
 558     OM_uint32 major, minor;
 559     size_t i, count = 0;
 560     void *plugs = NULL;
 561
 562     *pluglist = NULL;
 563     *plugcount = 0;
 564
 565     if (gs2_indicate_mechs(utils) != SASL_OK) {
 566         return SASL_NOMECH;
 567     }
 568
 569     plugs = utils->malloc(gs2_mechs->count * plugsize);
 570     if (plugs == NULL) {
 571         MEMERROR(utils);
 572         return SASL_NOMEM;
 573     }
 574     memset(plugs, 0, gs2_mechs->count * plugsize);
 575
 576     for (i = 0; i < gs2_mechs->count; i++) {
 577         gss_buffer_desc sasl_mech_name = GSS_C_EMPTY_BUFFER;
 578
 579         major = gss_inquire_saslname_for_mech(&minor,
 580                                               &gs2_mechs->elements[i],
 581                                               &sasl_mech_name,
 582                                               GSS_C_NO_BUFFER,
 583                                               GSS_C_NO_BUFFER);
 584         if (GSS_ERROR(major))
 585             continue;
 586
 587 #define PLUG_AT(index)      (void *)((unsigned char *)plugs + (count * plugsize))
 588
 589         if (plug_alloc(utils, PLUG_AT(count), &sasl_mech_name,
 590                        &gs2_mechs->elements[i]) == SASL_OK)
 591             count++;
 592
 593         gss_release_buffer(&minor, &sasl_mech_name);
 594     }
 595
 596     if (count == 0) {
 597         utils->free(plugs);
 598         return SASL_NOMECH;
 599     }
 600
 601     *pluglist = plugs;
 602     *plugcount = count;
 603
 604     return SASL_OK;
 605 }
 606
 607 static int
 608 gs2_server_plug_alloc(const sasl_utils_t *utils,
 609                       void *plug,
 610                       gss_buffer_t sasl_name,
 611                       gss_OID mech)
 612 {
 613     int ret;
 614     sasl_server_plug_t *splug = (sasl_server_plug_t *)plug;
 615     gss_buffer_desc buf;
 616
 617     memset(splug, 0, sizeof(*splug));
 618
 619     ret = gs2_get_mech_attrs(utils, mech,
 620                              &splug->security_flags,
 621                              &splug->features,
 622                              NULL);
 623     if (ret != SASL_OK)
 624         return ret;
 625
 626     ret = gs2_duplicate_buffer(utils, sasl_name, &buf);
 627     if (ret != SASL_OK)
 628         return ret;
 629
 630     splug->mech_name = (char *)buf.value;
 631     splug->glob_context = plug;
 632     splug->mech_new = gs2_server_mech_new;
 633     splug->mech_step = gs2_server_mech_step;
 634     splug->mech_dispose = gs2_common_mech_dispose;
 635     splug->mech_free = gs2_common_mech_free;
 636
 637     return SASL_OK;
 638 }
 639
 640 static sasl_server_plug_t *gs2_server_plugins;
 641 static int gs2_server_plugcount;
 642
 643 int
 644 gs2_server_plug_init(const sasl_utils_t *utils,
 645                      int maxversion,
 646                      int *outversion,
 647                      sasl_server_plug_t **pluglist,
 648                      int *plugcount)
 649 {
 650     int ret;
 651
 652     *pluglist = NULL;
 653     *plugcount = 0;
 654
 655     if (maxversion < SASL_SERVER_PLUG_VERSION)
 656         return SASL_BADVERS;
 657
 658     *outversion = SASL_SERVER_PLUG_VERSION;
 659
 660     if (gs2_server_plugins == NULL) {
 661         ret = gs2_common_plug_init(utils,
 662                                    sizeof(sasl_server_plug_t),
 663                                    gs2_server_plug_alloc,
 664                                    (void **)&gs2_server_plugins,
 665                                    &gs2_server_plugcount);
 666         if (ret != SASL_OK)
 667             return ret;
 668     }
 669
 670     *pluglist = gs2_server_plugins;
 671     *plugcount = gs2_server_plugcount;
 672
 673     return SASL_OK;
 674 }
 675
 676 /*****************************  Client Section  *****************************/
 677
 678 static int gs2_client_mech_step(void *conn_context,
 679                                 sasl_client_params_t *params,
 680                                 const char *serverin,
 681                                 unsigned serverinlen,
 682                                 sasl_interact_t **prompt_need,
 683                                 const char **clientout,
 684                                 unsigned *clientoutlen,
 685                                 sasl_out_params_t *oparams)
 686 {
 687     context_t *text = (context_t *)conn_context;
 688     gss_buffer_desc input_token = GSS_C_EMPTY_BUFFER;
 689     gss_buffer_desc output_token = GSS_C_EMPTY_BUFFER;
 690     gss_buffer_desc name_buf = GSS_C_EMPTY_BUFFER;
 691     OM_uint32 maj_stat = GSS_S_FAILURE, min_stat = 0;
 692     OM_uint32 req_flags, ret_flags;
 693     int ret = SASL_FAIL;
 694     int initialContextToken;
 695
 696     *clientout = NULL;
 697     *clientoutlen = 0;
 698
 699     if (text->gss_ctx == GSS_C_NO_CONTEXT) {
 700         ret = gs2_get_init_creds(text, params, prompt_need, oparams);
 701         if (ret != SASL_OK)
 702             goto cleanup;
 703
 704         initialContextToken = 1;
 705     } else
 706         initialContextToken = 0;
 707
 708     if (text->server_name == GSS_C_NO_NAME) { /* only once */
 709         name_buf.length = strlen(params->service) + 1 + strlen(params->serverFQDN);
 710         name_buf.value = params->utils->malloc(name_buf.length + 1);
 711         if (name_buf.value == NULL) {
 712             ret = SASL_NOMEM;
 713             goto cleanup;
 714         }
 715         if (params->serverFQDN == NULL ||
 716             strlen(params->serverFQDN) == 0) {
 717             SETERROR(text->utils, "GS2 Failure: no serverFQDN");
 718             ret = SASL_FAIL;
 719             goto cleanup;
 720         }
 721
 722         snprintf(name_buf.value, name_buf.length + 1,
 723                  "%s@%s", params->service, params->serverFQDN);
 724
 725         maj_stat = gss_import_name(&min_stat,
 726                                    &name_buf,
 727                                    GSS_C_NT_HOSTBASED_SERVICE,
 728                                    &text->server_name);
 729         params->utils->free(name_buf.value);
 730         name_buf.value = NULL;
 731
 732         if (GSS_ERROR(maj_stat))
 733             goto cleanup;
 734     }
 735
 736     /* From GSSAPI plugin: apparently this is for some IMAP bug workaround */
 737     if (serverinlen == 0 && text->gss_ctx != GSS_C_NO_CONTEXT) {
 738         gss_delete_sec_context(&min_stat, &text->gss_ctx, GSS_C_NO_BUFFER);
 739         text->gss_ctx = GSS_C_NO_CONTEXT;
 740     }
 741
 742     input_token.value = (void *)serverin;
 743     input_token.length = serverinlen;
 744
 745     if (initialContextToken) {
 746         if ((text->plug.client->features & SASL_FEAT_GSS_FRAMING) == 0)
 747             text->gs2_flags |= GS2_NONSTD_FLAG;
 748
 749         switch (params->cbindingdisp) {
 750         case SASL_CB_DISP_NONE:
 751             text->gs2_flags |= GS2_CB_FLAG_N;
 752             break;
 753         case SASL_CB_DISP_USED:
 754             text->gs2_flags |= GS2_CB_FLAG_P;
 755             break;
 756         case SASL_CB_DISP_WANT:
 757             text->gs2_flags |= GS2_CB_FLAG_Y;
 758             break;
 759         }
 760
 761         ret = gs2_make_header(text, params,
 762                               strcmp(oparams->user, oparams->authid) ?
 763                                      (char *) oparams->user : NULL,
 764                               &text->out_buf, &text->out_buf_len);
 765         if (ret != 0)
 766             goto cleanup;
 767     }
 768
 769     req_flags = GSS_C_MUTUAL_FLAG | GSS_C_SEQUENCE_FLAG;
 770
 771     maj_stat = gss_init_sec_context(&min_stat,
 772                                     (params->gss_creds != GSS_C_NO_CREDENTIAL)
 773                                         ? (gss_cred_id_t)params->gss_creds
 774                                         : text->client_creds,
 775                                     &text->gss_ctx,
 776                                     text->server_name,
 777                                     (gss_OID)text->mechanism,
 778                                     req_flags,
 779                                     GSS_C_INDEFINITE,
 780                                     &text->gss_cbindings,
 781                                     serverinlen ? &input_token : GSS_C_NO_BUFFER,
 782                                     NULL,
 783                                     &output_token,
 784                                     &ret_flags,
 785                                     &text->lifetime);
 786     if (GSS_ERROR(maj_stat))
 787         goto cleanup;
 788
 789     ret = gs2_make_message(text, params, initialContextToken, &output_token,
 790                            &text->out_buf, &text->out_buf_len);
 791     if (ret != 0)
 792         goto cleanup;
 793
 794     *clientout = text->out_buf;
 795     *clientoutlen = text->out_buf_len;
 796
 797     if (maj_stat == GSS_S_CONTINUE_NEEDED) {
 798         ret = SASL_CONTINUE;
 799         goto cleanup;
 800     }
 801
 802     if (text->client_name != GSS_C_NO_NAME)
 803         gss_release_name(&min_stat, &text->client_name);
 804
 805     maj_stat = gss_inquire_context(&min_stat,
 806                                    text->gss_ctx,
 807                                    &text->client_name,
 808                                    NULL,
 809                                    &text->lifetime,
 810                                    NULL,
 811                                    &ret_flags, /* flags */
 812                                    NULL,
 813                                    NULL);
 814     if (GSS_ERROR(maj_stat))
 815         goto cleanup;
 816
 817     if ((ret_flags & req_flags) != req_flags) {
 818         maj_stat = SASL_BADAUTH;
 819         goto cleanup;
 820     }
 821
 822     maj_stat = gss_display_name(&min_stat,
 823                                 text->client_name,
 824                                 &name_buf,
 825                                 NULL);
 826     if (GSS_ERROR(maj_stat))
 827         goto cleanup;
 828
 829     oparams->gss_peer_name = text->server_name;
 830     oparams->gss_local_name = text->client_name;
 831     oparams->encode = NULL;
 832     oparams->decode = NULL;
 833     oparams->mech_ssf = 0;
 834     oparams->maxoutbuf = 0xFFFFFF;
 835     oparams->doneflag = 1;
 836
 837 cleanup:
 838     gss_release_buffer(&min_stat, &output_token);
 839     gss_release_buffer(&min_stat, &name_buf);
 840
 841     if (ret == SASL_OK && maj_stat != GSS_S_COMPLETE) {
 842         sasl_gs2_seterror(text->utils, maj_stat, min_stat);
 843         ret = SASL_FAIL;
 844     }
 845     if (ret != SASL_OK && ret != SASL_CONTINUE)
 846         sasl_gs2_free_context_contents(text);
 847
 848     return ret;
 849 }
 850
 851 static int gs2_client_mech_new(void *glob_context,
 852                                sasl_client_params_t *params,
 853                                void **conn_context)
 854 {
 855     context_t *text;
 856     int ret;
 857
 858     text = sasl_gs2_new_context(params->utils);
 859     if (text == NULL) {
 860         MEMERROR(params->utils);
 861         return SASL_NOMEM;
 862     }
 863
 864     text->gss_ctx = GSS_C_NO_CONTEXT;
 865     text->client_name = GSS_C_NO_NAME;
 866     text->server_creds = GSS_C_NO_CREDENTIAL;
 867     text->client_creds  = GSS_C_NO_CREDENTIAL;
 868     text->plug.client = glob_context;
 869
 870     ret = gs2_map_sasl_name(params->utils, text->plug.client->mech_name,
 871                             &text->mechanism);
 872     if (ret != SASL_OK) {
 873         gs2_common_mech_dispose(text, params->utils);
 874         return ret;
 875     }
 876
 877     *conn_context = text;
 878
 879     return SASL_OK;
 880 }
 881
 882 static int
 883 gs2_client_plug_alloc(const sasl_utils_t *utils,
 884                       void *plug,
 885                       gss_buffer_t sasl_name,
 886                       gss_OID mech)
 887 {
 888     int ret;
 889     sasl_client_plug_t *cplug = (sasl_client_plug_t *)plug;
 890     gss_buffer_desc buf;
 891
 892     memset(cplug, 0, sizeof(*cplug));
 893
 894     ret = gs2_get_mech_attrs(utils, mech,
 895                              &cplug->security_flags,
 896                              &cplug->features,
 897                              &cplug->required_prompts);
 898     if (ret != SASL_OK)
 899         return ret;
 900
 901     ret = gs2_duplicate_buffer(utils, sasl_name, &buf);
 902     if (ret != SASL_OK)
 903         return ret;
 904
 905     cplug->mech_name = (char *)buf.value;
 906     cplug->features |= SASL_FEAT_NEEDSERVERFQDN;
 907     cplug->glob_context = plug;
 908     cplug->mech_new = gs2_client_mech_new;
 909     cplug->mech_step = gs2_client_mech_step;
 910     cplug->mech_dispose = gs2_common_mech_dispose;
 911     cplug->mech_free = gs2_common_mech_free;
 912
 913     return SASL_OK;
 914 }
 915
 916 static sasl_client_plug_t *gs2_client_plugins;
 917 static int gs2_client_plugcount;
 918
 919 int
 920 gs2_client_plug_init(const sasl_utils_t *utils,
 921                      int maxversion,
 922                      int *outversion,
 923                      sasl_client_plug_t **pluglist,
 924                      int *plugcount)
 925 {
 926     int ret;
 927
 928     *pluglist = NULL;
 929     *plugcount = 0;
 930
 931     if (maxversion < SASL_CLIENT_PLUG_VERSION)
 932         return SASL_BADVERS;
 933
 934     *outversion = SASL_CLIENT_PLUG_VERSION;
 935
 936     if (gs2_client_plugins == NULL) {
 937         ret = gs2_common_plug_init(utils,
 938                                    sizeof(sasl_client_plug_t),
 939                                    gs2_client_plug_alloc,
 940                                    (void **)&gs2_client_plugins,
 941                                    &gs2_client_plugcount);
 942         if (ret != SASL_OK)
 943             return ret;
 944     }
 945
 946     *pluglist = gs2_client_plugins;
 947     *plugcount = gs2_client_plugcount;
 948
 949     return SASL_OK;
 950 }
 951
 952 /*
 953  * Copy header and application channel bindings to GSS channel bindings
 954  * structure in context.
 955  */
 956 static int
 957 gs2_save_cbindings(context_t *text,
 958                    gss_buffer_t header,
 959                    const sasl_channel_binding_t *cbinding)
 960 {
 961     gss_buffer_t gss_cbindings = &text->gss_cbindings.application_data;
 962     size_t len;
 963     unsigned char *p;
 964
 965     assert(gss_cbindings->value == NULL);
 966
 967     /*
 968      * The application-data field MUST be set to the gs2-header, excluding
 969      * the initial [gs2-nonstd-flag ","] part, concatenated with, when a
 970      * gs2-cb-flag of "p" is used, the application's channel binding data.
 971      */
 972     len = header->length;
 973     if (text->gs2_flags & GS2_NONSTD_FLAG) {
 974         assert(len > 2);
 975         len -= 2;
 976     }
 977     if ((text->gs2_flags & GS2_CB_FLAG_MASK) == GS2_CB_FLAG_P &&
 978         cbinding != NULL) {
 979         len += cbinding->len;
 980     }
 981
 982     gss_cbindings->length = len;
 983     gss_cbindings->value = text->utils->malloc(len);
 984     if (gss_cbindings->value == NULL)
 985         return SASL_NOMEM;
 986
 987     p = (unsigned char *)gss_cbindings->value;
 988     if (text->gs2_flags & GS2_NONSTD_FLAG) {
 989         memcpy(p, (unsigned char *)header->value + 2, header->length - 2);
 990         p += header->length - 2;
 991     } else {
 992         memcpy(p, header->value, header->length);
 993         p += header->length;
 994     }
 995
 996     if ((text->gs2_flags & GS2_CB_FLAG_MASK) == GS2_CB_FLAG_P &&
 997         cbinding != NULL) {
 998         memcpy(p, cbinding->data, cbinding->len);
 999     }
1000
1001     return SASL_OK;
1002 }
1003
1004 #define CHECK_REMAIN(n)     do { if (remain < (n)) return SASL_BADPROT; } while (0)
1005
1006 /*
1007  * Verify gs2-header, save authzid and channel bindings to context.
1008  */
1009 static int
1010 gs2_verify_initial_message(context_t *text,
1011                            sasl_server_params_t *sparams,
1012                            const char *in,
1013                            unsigned inlen,
1014                            gss_buffer_t token)
1015 {
1016     OM_uint32 major, minor;
1017     char *p = (char *)in;
1018     unsigned remain = inlen;
1019     int ret;
1020     gss_buffer_desc buf = GSS_C_EMPTY_BUFFER;
1021
1022     assert(text->cbindingname == NULL);
1023     assert(text->authzid == NULL);
1024
1025     token->length = 0;
1026     token->value = NULL;
1027
1028     /* minimum header includes CB flag and non-zero GSS token */
1029     CHECK_REMAIN(4); /* [pny],,. */
1030
1031     /* non-standard GSS framing flag */
1032     if (remain > 1 && memcmp(p, "F,", 2) == 0) {
1033         text->gs2_flags |= GS2_NONSTD_FLAG;
1034         remain -= 2;
1035         p += 2;
1036     }
1037
1038     /* SASL channel bindings */
1039     CHECK_REMAIN(1); /* [pny] */
1040     remain--;
1041     switch (*p++) {
1042     case 'p':
1043         CHECK_REMAIN(1); /* = */
1044         remain--;
1045         if (*p++ != '=')
1046             return SASL_BADPROT;
1047
1048         ret = gs2_unescape_authzid(text->utils, &p, &remain, &text->cbindingname);
1049         if (ret != SASL_OK)
1050             return ret;
1051
1052         text->gs2_flags |= GS2_CB_FLAG_P;
1053         break;
1054     case 'n':
1055         text->gs2_flags |= GS2_CB_FLAG_N;
1056         break;
1057     case 'y':
1058         text->gs2_flags |= GS2_CB_FLAG_Y;
1059         break;
1060     }
1061
1062     CHECK_REMAIN(1); /* , */
1063     remain--;
1064     if (*p++ != ',')
1065         return SASL_BADPROT;
1066
1067     /* authorization identity */
1068     if (remain > 1 && memcmp(p, "a=", 2) == 0) {
1069         CHECK_REMAIN(2);
1070         remain -= 2;
1071         p += 2;
1072
1073         ret = gs2_unescape_authzid(text->utils, &p, &remain, &text->authzid);
1074         if (ret != SASL_OK)
1075             return ret;
1076     }
1077
1078     /* end of header */
1079     CHECK_REMAIN(1); /* , */
1080     remain--;
1081     if (*p++ != ',')
1082         return SASL_BADPROT;
1083
1084     buf.length = inlen - remain;
1085     buf.value = (void *)in;
1086
1087     /* stash channel bindings to pass into gss_accept_sec_context() */
1088     ret = gs2_save_cbindings(text, &buf, sparams->cbinding);
1089     if (ret != SASL_OK)
1090         return ret;
1091
1092     if (text->gs2_flags & GS2_NONSTD_FLAG) {
1093         buf.length = remain;
1094         buf.value = p;
1095     } else {
1096         gss_buffer_desc tmp;
1097
1098         tmp.length = remain;
1099         tmp.value = p;
1100
1101         major = gss_encapsulate_token(&tmp, text->mechanism, &buf);
1102         if (GSS_ERROR(major))
1103             return SASL_NOMEM;
1104     }
1105
1106     token->value = text->utils->malloc(buf.length);
1107     if (token->value == NULL)
1108         return SASL_NOMEM;
1109
1110     token->length = buf.length;
1111     memcpy(token->value, buf.value, buf.length);
1112
1113     if ((text->gs2_flags & GS2_NONSTD_FLAG) == 0)
1114         gss_release_buffer(&minor, &buf);
1115
1116     return SASL_OK;
1117 }
1118
1119 /*
1120  * Create gs2-header, save channel bindings to context.
1121  */
1122 static int
1123 gs2_make_header(context_t *text,
1124                 sasl_client_params_t *cparams,
1125                 const char *authzid,
1126                 char **out,
1127                 unsigned *outlen)
1128 {
1129     size_t required = 0;
1130     size_t wire_authzid_len = 0, cbnamelen = 0;
1131     char *wire_authzid = NULL;
1132     char *p;
1133     int ret;
1134     gss_buffer_desc buf;
1135
1136     *out = NULL;
1137     *outlen = 0;
1138
1139     /* non-standard GSS framing flag */
1140     if (text->gs2_flags & GS2_NONSTD_FLAG)
1141         required += 2; /* F, */
1142
1143     /* SASL channel bindings */
1144     switch (text->gs2_flags & GS2_CB_FLAG_MASK) {
1145     case GS2_CB_FLAG_P:
1146         if (!SASL_CB_PRESENT(cparams))
1147             return SASL_BADPARAM;
1148         cbnamelen = strlen(cparams->cbinding->name);
1149         required += 1 /*=*/ + cbnamelen;
1150         /* fallthrough */
1151     case GS2_CB_FLAG_N:
1152     case GS2_CB_FLAG_Y:
1153         required += 2; /* [pny], */
1154         break;
1155     default:
1156         return SASL_BADPARAM;
1157     }
1158
1159     /* authorization identity */
1160     if (authzid != NULL) {
1161         ret = gs2_escape_authzid(text->utils, authzid,
1162                                  strlen(authzid), &wire_authzid);
1163         if (ret != SASL_OK)
1164             return ret;
1165
1166         wire_authzid_len = strlen(wire_authzid);
1167         required += 2 /* a= */ + wire_authzid_len;
1168     }
1169
1170     required += 1; /* trailing comma */
1171
1172     ret = _plug_buf_alloc(text->utils, out, outlen, required);
1173     if (ret != SASL_OK) {
1174         text->utils->free(wire_authzid);
1175         return ret;
1176     }
1177
1178     *out = text->out_buf;
1179     *outlen = required;
1180
1181     p = (char *)text->out_buf;
1182     if (text->gs2_flags & GS2_NONSTD_FLAG) {
1183         *p++ = 'F';
1184         *p++ = ',';
1185     }
1186     switch (text->gs2_flags & GS2_CB_FLAG_MASK) {
1187     case GS2_CB_FLAG_P:
1188         memcpy(p, "p=", 2);
1189         memcpy(p + 2, cparams->cbinding->name, cbnamelen);
1190         p += 2 + cbnamelen;
1191         break;
1192     case GS2_CB_FLAG_N:
1193         *p++ = 'n';
1194         break;
1195     case GS2_CB_FLAG_Y:
1196         *p++ = 'y';
1197         break;
1198     }
1199     *p++ = ',';
1200     if (wire_authzid != NULL) {
1201         memcpy(p, "a=", 2);
1202         memcpy(p + 2, wire_authzid, wire_authzid_len);
1203         text->utils->free(wire_authzid);
1204         p += 2 + wire_authzid_len;
1205     }
1206     *p++ = ',';
1207
1208     assert(p == (char *)text->out_buf + required);
1209
1210     buf.length = required;
1211     buf.value = *out;
1212
1213     ret = gs2_save_cbindings(text, &buf, cparams->cbinding);
1214     if (ret != SASL_OK)
1215         return ret;
1216
1217     return SASL_OK;
1218 }
1219
1220 /*
1221  * Convert a GSS token to a GS2 one
1222  */
1223 static int
1224 gs2_make_message(context_t *text,
1225                  sasl_client_params_t *cparams __attribute__((unused)),
1226                  int initialContextToken,
1227                  gss_buffer_t token,
1228                  char **out,
1229                  unsigned *outlen)
1230 {
1231     OM_uint32 major, minor;
1232     int ret;
1233     unsigned header_len = 0;
1234     gss_buffer_desc decap_token = GSS_C_EMPTY_BUFFER;
1235
1236     if (initialContextToken) {
1237         header_len = *outlen;
1238
1239         major = gss_decapsulate_token(token, text->mechanism, &decap_token);
1240         if ((major == GSS_S_DEFECTIVE_TOKEN &&
1241              (text->plug.client->features & SASL_FEAT_GSS_FRAMING)) ||
1242             GSS_ERROR(major))
1243             return SASL_FAIL;
1244
1245         token = &decap_token;
1246     }
1247
1248     ret = _plug_buf_alloc(text->utils, out, outlen,
1249                           header_len + token->length);
1250     if (ret != 0)
1251         return ret;
1252
1253     memcpy(*out + header_len, token->value, token->length);
1254     *outlen = header_len + token->length;
1255
1256     if (initialContextToken)
1257         gss_release_buffer(&minor, &decap_token);
1258
1259     return SASL_OK;
1260 }
1261
1262 static const unsigned long gs2_required_prompts[] = {
1263     SASL_CB_LIST_END
1264 };
1265
1266 /*
1267  * Map GSS mechanism attributes to SASL ones
1268  */
1269 static int
1270 gs2_get_mech_attrs(const sasl_utils_t *utils,
1271                    const gss_OID mech,
1272                    unsigned int *security_flags,
1273                    unsigned int *features,
1274                    const unsigned long **prompts)
1275 {
1276     OM_uint32 major, minor;
1277     int present;
1278     gss_OID_set attrs = GSS_C_NO_OID_SET;
1279
1280     major = gss_inquire_attrs_for_mech(&minor, mech, &attrs, NULL);
1281     if (GSS_ERROR(major)) {
1282         utils->seterror(utils->conn, SASL_NOLOG,
1283                         "GS2 Failure: gss_inquire_attrs_for_mech");
1284         return SASL_FAIL;
1285     }
1286
1287     *security_flags = SASL_SEC_NOPLAINTEXT | SASL_SEC_NOACTIVE;
1288     *features = SASL_FEAT_WANT_CLIENT_FIRST | SASL_FEAT_CHANNEL_BINDING;
1289     if (prompts != NULL)
1290         *prompts = gs2_required_prompts;
1291
1292 #define MA_PRESENT(a)   (gss_test_oid_set_member(&minor, (gss_OID)(a), \
1293                                                  attrs, &present) == GSS_S_COMPLETE && \
1294                          present)
1295
1296     if (MA_PRESENT(GSS_C_MA_PFS))
1297         *security_flags |= SASL_SEC_FORWARD_SECRECY;
1298     if (!MA_PRESENT(GSS_C_MA_AUTH_INIT_ANON))
1299         *security_flags |= SASL_SEC_NOANONYMOUS;
1300     if (MA_PRESENT(GSS_C_MA_DELEG_CRED))
1301         *security_flags |= SASL_SEC_PASS_CREDENTIALS;
1302     if (MA_PRESENT(GSS_C_MA_AUTH_TARG))
1303         *security_flags |= SASL_SEC_MUTUAL_AUTH;
1304     if (MA_PRESENT(GSS_C_MA_AUTH_INIT_INIT) && prompts != NULL)
1305         *prompts = NULL;
1306     if (MA_PRESENT(GSS_C_MA_ITOK_FRAMED))
1307         *features |= SASL_FEAT_GSS_FRAMING;
1308
1309     gss_release_oid_set(&minor, &attrs);
1310
1311     return SASL_OK;
1312 }
1313
1314 /*
1315  * Enumerate GSS mechanisms that can be used for GS2
1316  */
1317 static int gs2_indicate_mechs(const sasl_utils_t *utils)
1318 {
1319     OM_uint32 major, minor;
1320     gss_OID_desc desired_oids[3];
1321     gss_OID_set_desc desired_attrs;
1322     gss_OID_desc except_oids[3];
1323     gss_OID_set_desc except_attrs;
1324
1325     if (gs2_mechs != GSS_C_NO_OID_SET)
1326         return SASL_OK;
1327
1328     desired_oids[0] = *GSS_C_MA_AUTH_INIT;
1329     desired_oids[1] = *GSS_C_MA_AUTH_TARG;
1330     desired_oids[2] = *GSS_C_MA_CBINDINGS;
1331     desired_attrs.count = sizeof(desired_oids)/sizeof(desired_oids[0]);
1332     desired_attrs.elements = desired_oids;
1333
1334     except_oids[0] = *GSS_C_MA_MECH_NEGO;
1335     except_oids[1] = *GSS_C_MA_NOT_MECH;
1336     except_oids[2] = *GSS_C_MA_DEPRECATED;
1337
1338     except_attrs.count = sizeof(except_oids)/sizeof(except_oids[0]);
1339     except_attrs.elements = except_oids;
1340
1341     major = gss_indicate_mechs_by_attrs(&minor,
1342                                         &desired_attrs,
1343                                         &except_attrs,
1344                                         GSS_C_NO_OID_SET,
1345                                         &gs2_mechs);
1346     if (GSS_ERROR(major)) {
1347         utils->seterror(utils->conn, SASL_NOLOG,
1348                         "GS2 Failure: gss_indicate_mechs_by_attrs");
1349         return SASL_FAIL;
1350     }
1351
1352     return (gs2_mechs->count > 0) ? SASL_OK : SASL_NOMECH;
1353 }
1354
1355 /*
1356  * Map SASL mechanism name to OID
1357  */
1358 static int
1359 gs2_map_sasl_name(const sasl_utils_t *utils,
1360                   const char *mech,
1361                   gss_OID *oid)
1362 {
1363     OM_uint32 major, minor;
1364     gss_buffer_desc buf;
1365
1366     buf.length = strlen(mech);
1367     buf.value = (void *)mech;
1368
1369     major = gss_inquire_mech_for_saslname(&minor, &buf, oid);
1370     if (GSS_ERROR(major)) {
1371         utils->seterror(utils->conn, SASL_NOLOG,
1372                         "GS2 Failure: gss_inquire_mech_for_saslname");
1373         return SASL_FAIL;
1374     }
1375
1376     return SASL_OK;
1377 }
1378
1379 static int
1380 gs2_duplicate_buffer(const sasl_utils_t *utils,
1381                      const gss_buffer_t src,
1382                      gss_buffer_t dst)
1383 {
1384     dst->value = utils->malloc(src->length + 1);
1385     if (dst->value == NULL)
1386         return SASL_NOMEM;
1387
1388     memcpy(dst->value, src->value, src->length);
1389     ((char *)dst->value)[src->length] = '\0';
1390     dst->length = src->length;
1391
1392     return SASL_OK;
1393 }
1394
1395 static int
1396 gs2_unescape_authzid(const sasl_utils_t *utils,
1397                      char **endp,
1398                      unsigned *remain,
1399                      char **authzid)
1400 {
1401     char *in = *endp;
1402     size_t i, len, inlen = *remain;
1403     char *p;
1404
1405     *endp = NULL;
1406
1407     for (i = 0, len = 0; i < inlen; i++) {
1408         if (in[i] == ',') {
1409             *endp = &in[i];
1410             *remain -= i;
1411             break;
1412         } else if (in[i] == '=') {
1413             if (inlen <= i + 2)
1414                 return SASL_BADPROT;
1415             i += 2;
1416         }
1417         len++;
1418     }
1419
1420     if (len == 0 || *endp == NULL)
1421         return SASL_BADPROT;
1422
1423     p = *authzid = utils->malloc(len + 1);
1424     if (*authzid == NULL)
1425         return SASL_NOMEM;
1426
1427     for (i = 0; i < inlen; i++) {
1428         if (in[i] == ',')
1429             break;
1430         else if (in[i] == '=') {
1431             if (memcmp(&in[i + 1], "2C", 2) == 0)
1432                 *p++ = ',';
1433             else if (memcmp(&in[i + 1], "3D", 2) == 0)
1434                 *p++ = '=';
1435             else {
1436                 utils->free(*authzid);
1437                 *authzid = NULL;
1438                 return SASL_BADPROT;
1439             }
1440             i += 2;
1441         } else
1442             *p++ = in[i];
1443     }
1444
1445     *p = '\0';
1446
1447     return SASL_OK;
1448 }
1449
1450 static int
1451 gs2_escape_authzid(const sasl_utils_t *utils,
1452                    const char *in,
1453                    unsigned inlen,
1454                    char **authzid)
1455 {
1456     size_t i;
1457     char *p;
1458
1459     p = *authzid = utils->malloc((inlen * 3) + 1);
1460     if (*authzid == NULL)
1461         return SASL_NOMEM;
1462
1463     for (i = 0; i < inlen; i++) {
1464         if (in[i] == ',') {
1465             memcpy(p, "=2C", 3);
1466             p += 3;
1467         } else if (in[i] == '=') {
1468             memcpy(p, "=3D", 3);
1469             p += 3;
1470         } else {
1471             *p++ = in[i];
1472         }
1473     }
1474
1475     *p = '\0';
1476
1477     return SASL_OK;
1478 }
1479
1480 #define GOT_CREDS(text, params) ((text)->client_creds != NULL || (params)->gss_creds != NULL)
1481 #define CRED_ERROR(status)      ((status) == GSS_S_CRED_UNAVAIL || (status) == GSS_S_NO_CRED)
1482
1483 /*
1484  * Determine the authentication identity from the application supplied
1485  * GSS credential, the application supplied identity, and the default
1486  * GSS credential, in that order. Then, acquire credentials.
1487  */
1488 static int
1489 gs2_get_init_creds(context_t *text,
1490                    sasl_client_params_t *params,
1491                    sasl_interact_t **prompt_need,
1492                    sasl_out_params_t *oparams)
1493 {
1494     int result = SASL_OK;
1495     const char *authid = NULL, *userid = NULL;
1496     int user_result = SASL_OK;
1497     int auth_result = SASL_OK;
1498     int pass_result = SASL_OK;
1499     OM_uint32 maj_stat = GSS_S_COMPLETE, min_stat = 0;
1500     gss_OID_set_desc mechs;
1501     gss_buffer_desc cred_authid = GSS_C_EMPTY_BUFFER;
1502     gss_buffer_desc name_buf = GSS_C_EMPTY_BUFFER;
1503
1504     mechs.count = 1;
1505     mechs.elements = (gss_OID)text->mechanism;
1506
1507     /*
1508      * Get the authentication identity from the application.
1509      */
1510     if (oparams->authid == NULL) {
1511         auth_result = _plug_get_authid(params->utils, &authid, prompt_need);
1512         if (auth_result != SASL_OK && auth_result != SASL_INTERACT) {
1513             result = auth_result;
1514             goto cleanup;
1515         }
1516     }
1517
1518     /*
1519      * Get the authorization identity from the application.
1520      */
1521     if (oparams->user == NULL) {
1522         user_result = _plug_get_userid(params->utils, &userid, prompt_need);
1523         if (user_result != SASL_OK && user_result != SASL_INTERACT) {
1524             result = user_result;
1525             goto cleanup;
1526         }
1527     }
1528
1529     /*
1530      * Canonicalize the authentication and authorization identities before
1531      * calling GSS_Import_name.
1532      */
1533     if (auth_result == SASL_OK && user_result == SASL_OK &&
1534         oparams->authid == NULL) {
1535         if (userid == NULL || userid[0] == '\0') {
1536             result = params->canon_user(params->utils->conn, authid, 0,
1537                                         SASL_CU_AUTHID | SASL_CU_AUTHZID,
1538                                         oparams);
1539         } else {
1540             result = params->canon_user(params->utils->conn,
1541                                         authid, 0, SASL_CU_AUTHID, oparams);
1542             if (result != SASL_OK)
1543                 goto cleanup;
1544
1545             result = params->canon_user(params->utils->conn,
1546                                         userid, 0, SASL_CU_AUTHZID, oparams);
1547             if (result != SASL_OK)
1548                 goto cleanup;
1549         }
1550
1551         if (oparams->authid != NULL) {
1552             name_buf.length = strlen(oparams->authid);
1553             name_buf.value = (void *)oparams->authid;
1554
1555             assert(text->client_name == GSS_C_NO_NAME);
1556
1557             maj_stat = gss_import_name(&min_stat,
1558                                        &name_buf,
1559                                        GSS_C_NT_USER_NAME,
1560                                        &text->client_name);
1561             if (GSS_ERROR(maj_stat))
1562                 goto cleanup;
1563         }
1564     }
1565
1566     /*
1567      * If application didn't provide an authid, then use the default
1568      * credential. If that doesn't work, give up.
1569      */
1570     if (!GOT_CREDS(text, params) && oparams->authid == NULL) {
1571         maj_stat = gss_acquire_cred(&min_stat,
1572                                     GSS_C_NO_NAME,
1573                                     GSS_C_INDEFINITE,
1574                                     &mechs,
1575                                     GSS_C_INITIATE,
1576                                     &text->client_creds,
1577                                     NULL,
1578                                     &text->lifetime);
1579         if (GSS_ERROR(maj_stat))
1580             goto cleanup;
1581
1582         assert(text->client_name == GSS_C_NO_NAME);
1583
1584         maj_stat = gss_inquire_cred(&min_stat,
1585                                     params->gss_creds
1586                                         ? (gss_cred_id_t)params->gss_creds
1587                                         : text->client_creds,
1588                                     &text->client_name,
1589                                     NULL,
1590                                     NULL,
1591                                     NULL);
1592         if (GSS_ERROR(maj_stat))
1593             goto cleanup;
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     /* free prompts we got */
1675     if (prompt_need && *prompt_need) {
1676         params->utils->free(*prompt_need);
1677         *prompt_need = NULL;
1678     }
1679
1680     /* if there are prompts not filled in */
1681     if (user_result == SASL_INTERACT || auth_result == SASL_INTERACT ||
1682         pass_result == SASL_INTERACT) {
1683         /* make the prompt list */
1684         result =
1685             _plug_make_prompts(params->utils, prompt_need,
1686                                user_result == SASL_INTERACT ?
1687                                "Please enter your authorization name" : NULL,
1688                                NULL,
1689                                auth_result == SASL_INTERACT ?
1690                                "Please enter your authentication name" : NULL,
1691                                NULL,
1692                                pass_result == SASL_INTERACT ?
1693                                "Please enter your password" : NULL, NULL,
1694                                NULL, NULL, NULL,
1695                                NULL,
1696                                NULL, NULL);
1697         if (result == SASL_OK)
1698             result = SASL_INTERACT;
1699     }
1700
1701 cleanup:
1702     if (result == SASL_OK && maj_stat != GSS_S_COMPLETE) {
1703         sasl_gs2_seterror(text->utils, maj_stat, min_stat);
1704         result = SASL_FAIL;
1705     }
1706
1707     gss_release_buffer(&min_stat, &cred_authid);
1708
1709     return result;
1710 }
1711
1712 static int
1713 sasl_gs2_seterror_(const sasl_utils_t *utils, OM_uint32 maj, OM_uint32 min,
1714                    int logonly)
1715 {
1716     OM_uint32 maj_stat, min_stat;
1717     gss_buffer_desc msg;
1718     OM_uint32 msg_ctx;
1719     int ret;
1720     char *out = NULL;
1721     unsigned int len, curlen = 0;
1722     const char prefix[] = "GS2 Error: ";
1723
1724     len = sizeof(prefix);
1725     ret = _plug_buf_alloc(utils, &out, &curlen, 256);
1726     if (ret != SASL_OK)
1727         return SASL_OK;
1728
1729     strcpy(out, prefix);
1730
1731     msg_ctx = 0;
1732     while (1) {
1733         maj_stat = gss_display_status(&min_stat, maj,
1734                                       GSS_C_GSS_CODE, GSS_C_NULL_OID,
1735                                       &msg_ctx, &msg);
1736
1737         if (GSS_ERROR(maj_stat)) {
1738             if (logonly) {
1739                 utils->log(utils->conn, SASL_LOG_FAIL,
1740                         "GS2 Failure: (could not get major error message)");
1741             } else {
1742                 utils->seterror(utils->conn, 0,
1743                                 "GS2 Failure "
1744                                 "(could not get major error message)");
1745             }
1746             utils->free(out);
1747             return SASL_OK;
1748         }
1749
1750         len += len + msg.length;
1751         ret = _plug_buf_alloc(utils, &out, &curlen, len);
1752         if (ret != SASL_OK) {
1753             utils->free(out);
1754             return SASL_OK;
1755         }
1756
1757         strcat(out, msg.value);
1758
1759         gss_release_buffer(&min_stat, &msg);
1760
1761         if (!msg_ctx)
1762             break;
1763     }
1764
1765     /* Now get the minor status */
1766
1767     len += 2;
1768     ret = _plug_buf_alloc(utils, &out, &curlen, len);
1769     if (ret != SASL_OK) {
1770         utils->free(out);
1771         return SASL_NOMEM;
1772     }
1773
1774     strcat(out, " (");
1775
1776     msg_ctx = 0;
1777     while (1) {
1778         maj_stat = gss_display_status(&min_stat, min,
1779                                       GSS_C_MECH_CODE, GSS_C_NULL_OID,
1780                                       &msg_ctx, &msg);
1781
1782         if (GSS_ERROR(maj_stat)) {
1783             if (logonly) {
1784                 utils->log(utils->conn, SASL_LOG_FAIL,
1785                         "GS2 Failure: (could not get minor error message)");
1786             } else {
1787                 utils->seterror(utils->conn, 0,
1788                                 "GS2 Failure "
1789                                 "(could not get minor error message)");
1790             }
1791             utils->free(out);
1792             return SASL_OK;
1793         }
1794
1795         len += len + msg.length;
1796
1797         ret = _plug_buf_alloc(utils, &out, &curlen, len);
1798         if (ret != SASL_OK) {
1799             utils->free(out);
1800             return SASL_NOMEM;
1801         }
1802
1803         strcat(out, msg.value);
1804
1805         gss_release_buffer(&min_stat, &msg);
1806
1807         if (!msg_ctx)
1808             break;
1809     }
1810
1811     len += 1;
1812     ret = _plug_buf_alloc(utils, &out, &curlen, len);
1813     if (ret != SASL_OK) {
1814         utils->free(out);
1815         return SASL_NOMEM;
1816     }
1817
1818     strcat(out, ")");
1819
1820     if (logonly) {
1821         utils->log(utils->conn, SASL_LOG_FAIL, out);
1822     } else {
1823         utils->seterror(utils->conn, 0, out);
1824     }
1825     utils->free(out);
1826
1827     return SASL_OK;
1828 }