citadel/modules/openid/serv_openid_rp.c

   1 /*
   2  * This is an implementation of OpenID 2.0 relying party support in stateless mode.
   3  *
   4  * Copyright (c) 2007-2020 by the citadel.org team
   5  *
   6  * This program is open source software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "sysdep.h"
  21 #include <stdlib.h>
  22 #include <unistd.h>
  23 #include <stdio.h>
  24 #include <fcntl.h>
  25 #include <signal.h>
  26 #include <pwd.h>
  27 #include <errno.h>
  28 #include <sys/types.h>
  29
  30 #if TIME_WITH_SYS_TIME
  31 # include <sys/time.h>
  32 # include <time.h>
  33 #else
  34 # if HAVE_SYS_TIME_H
  35 #  include <sys/time.h>
  36 # else
  37 #  include <time.h>
  38 # endif
  39 #endif
  40
  41 #include <sys/wait.h>
  42 #include <string.h>
  43 #include <limits.h>
  44 #include <curl/curl.h>
  45 #include <expat.h>
  46 #include "ctdl_module.h"
  47 #include "config.h"
  48 #include "citserver.h"
  49 #include "user_ops.h"
  50
  51 typedef struct _ctdl_openid {
  52         StrBuf *op_url;                 /* OpenID Provider Endpoint URL */
  53         StrBuf *claimed_id;             /* Claimed Identifier */
  54         int verified;
  55         HashList *sreg_keys;
  56 } ctdl_openid;
  57
  58 enum {
  59         openid_disco_none,
  60         openid_disco_xrds,
  61         openid_disco_html
  62 };
  63
  64
  65 void Free_ctdl_openid(ctdl_openid **FreeMe)
  66 {
  67         if (*FreeMe == NULL) {
  68                 return;
  69         }
  70         FreeStrBuf(&(*FreeMe)->op_url);
  71         FreeStrBuf(&(*FreeMe)->claimed_id);
  72         DeleteHash(&(*FreeMe)->sreg_keys);
  73         free(*FreeMe);
  74         *FreeMe = NULL;
  75 }
  76
  77
  78 /*
  79  * This cleanup function blows away the temporary memory used by this module.
  80  */
  81 void openid_cleanup_function(void) {
  82         struct CitContext *CCC = CC;    /* CachedCitContext - performance boost */
  83
  84         if (CCC->openid_data != NULL) {
  85                 syslog(LOG_DEBUG, "openid: Clearing OpenID session state");
  86                 Free_ctdl_openid((ctdl_openid **) &CCC->openid_data);
  87         }
  88 }
  89
  90
  91 /**************************************************************************/
  92 /*                                                                        */
  93 /* Functions in this section handle Citadel internal OpenID mapping stuff */
  94 /*                                                                        */
  95 /**************************************************************************/
  96
  97
  98 /*
  99  * The structure of an openid record *key* is:
 100  *
 101  * |--------------claimed_id-------------|
 102  *     (actual length of claimed id)
 103  *
 104  *
 105  * The structure of an openid record *value* is:
 106  *
 107  * |-----user_number----|------------claimed_id---------------|
 108  *    (sizeof long)          (actual length of claimed id)
 109  *
 110  */
 111
 112
 113
 114 /*
 115  * Attach an external authenticator (such as an OpenID) to a Citadel account
 116  */
 117 int attach_extauth(struct ctdluser *who, StrBuf *claimed_id)
 118 {
 119         struct cdbdata *cdboi;
 120         long fetched_usernum;
 121         char *data;
 122         int data_len;
 123         char buf[2048];
 124
 125         if (!who) return(1);
 126         if (StrLength(claimed_id)==0) return(1);
 127
 128         /* Check to see if this authenticator is already in the database */
 129
 130         cdboi = cdb_fetch(CDB_EXTAUTH, ChrPtr(claimed_id), StrLength(claimed_id));
 131         if (cdboi != NULL) {
 132                 memcpy(&fetched_usernum, cdboi->ptr, sizeof(long));
 133                 cdb_free(cdboi);
 134
 135                 if (fetched_usernum == who->usernum) {
 136                         syslog(LOG_INFO, "openid: %s already associated; no action is taken", ChrPtr(claimed_id));
 137                         return(0);
 138                 }
 139                 else {
 140                         syslog(LOG_INFO, "openid: %s already belongs to another user", ChrPtr(claimed_id));
 141                         return(3);
 142                 }
 143         }
 144
 145         /* Not already in the database, so attach it now */
 146
 147         data_len = sizeof(long) + StrLength(claimed_id) + 1;
 148         data = malloc(data_len);
 149
 150         memcpy(data, &who->usernum, sizeof(long));
 151         memcpy(&data[sizeof(long)], ChrPtr(claimed_id), StrLength(claimed_id) + 1);
 152
 153         cdb_store(CDB_EXTAUTH, ChrPtr(claimed_id), StrLength(claimed_id), data, data_len);
 154         free(data);
 155
 156         snprintf(buf, sizeof buf, "User <%s> (#%ld) is now associated with %s\n", who->fullname, who->usernum, ChrPtr(claimed_id));
 157         CtdlAideMessage(buf, "External authenticator claim");
 158         syslog(LOG_INFO, "openid: %s", buf);
 159         return(0);
 160 }
 161
 162
 163 /*
 164  * When a user is being deleted, we have to delete any OpenID associations
 165  */
 166 void extauth_purge(struct ctdluser *usbuf) {
 167         struct cdbdata *cdboi;
 168         HashList *keys = NULL;
 169         HashPos *HashPos;
 170         char *deleteme = NULL;
 171         long len;
 172         void *Value;
 173         const char *Key;
 174         long usernum = 0L;
 175
 176         keys = NewHash(1, NULL);
 177         if (!keys) return;
 178
 179         cdb_rewind(CDB_EXTAUTH);
 180         while (cdboi = cdb_next_item(CDB_EXTAUTH), cdboi != NULL) {
 181                 if (cdboi->len > sizeof(long)) {
 182                         memcpy(&usernum, cdboi->ptr, sizeof(long));
 183                         if (usernum == usbuf->usernum) {
 184                                 deleteme = strdup(cdboi->ptr + sizeof(long)),
 185                                 Put(keys, deleteme, strlen(deleteme), deleteme, NULL);
 186                         }
 187                 }
 188                 cdb_free(cdboi);
 189         }
 190
 191         /* Go through the hash list, deleting keys we stored in it */
 192
 193         HashPos = GetNewHashPos(keys, 0);
 194         while (GetNextHashPos(keys, HashPos, &len, &Key, &Value)!=0)
 195         {
 196                 syslog(LOG_DEBUG, "openid: deleting associated external authenticator <%s>", (char*)Value);
 197                 cdb_delete(CDB_EXTAUTH, Value, strlen(Value));
 198                 /* note: don't free(Value) -- deleting the hash list will handle this for us */
 199         }
 200         DeleteHashPos(&HashPos);
 201         DeleteHash(&keys);
 202 }
 203
 204
 205 /*
 206  * List the OpenIDs associated with the currently logged in account
 207  */
 208 void cmd_oidl(char *argbuf) {
 209         struct cdbdata *cdboi;
 210         long usernum = 0L;
 211
 212         if (CtdlGetConfigInt("c_disable_newu"))
 213         {
 214                 cprintf("%d this system does not support openid.\n", ERROR + CMD_NOT_SUPPORTED);
 215                 return;
 216         }
 217         if (CtdlAccessCheck(ac_logged_in)) return;
 218
 219         cdb_rewind(CDB_EXTAUTH);
 220         cprintf("%d Associated external authenticators:\n", LISTING_FOLLOWS);
 221
 222         while (cdboi = cdb_next_item(CDB_EXTAUTH), cdboi != NULL) {
 223                 if (cdboi->len > sizeof(long)) {
 224                         memcpy(&usernum, cdboi->ptr, sizeof(long));
 225                         if (usernum == CC->user.usernum) {
 226                                 cprintf("%s\n", cdboi->ptr + sizeof(long));
 227                         }
 228                 }
 229                 cdb_free(cdboi);
 230         }
 231         cprintf("000\n");
 232 }
 233
 234
 235 /*
 236  * List ALL OpenIDs in the database
 237  */
 238 void cmd_oida(char *argbuf) {
 239         struct cdbdata *cdboi;
 240         long usernum;
 241         struct ctdluser usbuf;
 242
 243         if (CtdlGetConfigInt("c_disable_newu"))
 244         {
 245                 cprintf("%d this system does not support openid.\n",
 246                         ERROR + CMD_NOT_SUPPORTED);
 247                 return;
 248         }
 249         if (CtdlAccessCheck(ac_aide)) return;
 250         cdb_rewind(CDB_EXTAUTH);
 251         cprintf("%d List of all OpenIDs in the database:\n", LISTING_FOLLOWS);
 252
 253         while (cdboi = cdb_next_item(CDB_EXTAUTH), cdboi != NULL) {
 254                 if (cdboi->len > sizeof(long)) {
 255                         memcpy(&usernum, cdboi->ptr, sizeof(long));
 256                         if (CtdlGetUserByNumber(&usbuf, usernum) != 0) {
 257                                 usbuf.fullname[0] = 0;
 258                         }
 259                         cprintf("%s|%ld|%s\n",
 260                                 cdboi->ptr + sizeof(long),
 261                                 usernum,
 262                                 usbuf.fullname
 263                         );
 264                 }
 265                 cdb_free(cdboi);
 266         }
 267         cprintf("000\n");
 268 }
 269
 270
 271 /*
 272  * Create a new user account, manually specifying the name, after successfully
 273  * verifying an OpenID (which will of course be attached to the account)
 274  */
 275 void cmd_oidc(char *argbuf) {
 276         ctdl_openid *oiddata = (ctdl_openid *) CC->openid_data;
 277
 278         if (CtdlGetConfigInt("c_disable_newu"))
 279         {
 280                 cprintf("%d this system does not support openid.\n",
 281                         ERROR + CMD_NOT_SUPPORTED);
 282                 return;
 283         }
 284         if ( (!oiddata) || (!oiddata->verified) ) {
 285                 cprintf("%d You have not verified an OpenID yet.\n", ERROR);
 286                 return;
 287         }
 288
 289         /* We can make the semantics of OIDC exactly the same as NEWU, simply
 290          * by _calling_ cmd_newu() and letting it run.  Very clever!
 291          */
 292         cmd_newu(argbuf);
 293
 294         /* Now, if this logged us in, we have to attach the OpenID */
 295         if (CC->logged_in) {
 296                 attach_extauth(&CC->user, oiddata->claimed_id);
 297         }
 298
 299 }
 300
 301
 302 /*
 303  * Detach an OpenID from the currently logged in account
 304  */
 305 void cmd_oidd(char *argbuf) {
 306         struct cdbdata *cdboi;
 307         char id_to_detach[1024];
 308         int this_is_mine = 0;
 309         long usernum = 0L;
 310
 311         if (CtdlGetConfigInt("c_disable_newu"))
 312         {
 313                 cprintf("%d this system does not support openid.\n",
 314                         ERROR + CMD_NOT_SUPPORTED);
 315                 return;
 316         }
 317         if (CtdlAccessCheck(ac_logged_in)) return;
 318         extract_token(id_to_detach, argbuf, 0, '|', sizeof id_to_detach);
 319         if (IsEmptyStr(id_to_detach)) {
 320                 cprintf("%d An empty OpenID URL is not allowed.\n", ERROR + ILLEGAL_VALUE);
 321         }
 322
 323         cdb_rewind(CDB_EXTAUTH);
 324         while (cdboi = cdb_next_item(CDB_EXTAUTH), cdboi != NULL) {
 325                 if (cdboi->len > sizeof(long)) {
 326                         memcpy(&usernum, cdboi->ptr, sizeof(long));
 327                         if (usernum == CC->user.usernum) {
 328                                 this_is_mine = 1;
 329                         }
 330                 }
 331                 cdb_free(cdboi);
 332         }
 333
 334         if (!this_is_mine) {
 335                 cprintf("%d That OpenID was not found or not associated with your account.\n",
 336                         ERROR + ILLEGAL_VALUE);
 337                 return;
 338         }
 339
 340         cdb_delete(CDB_EXTAUTH, id_to_detach, strlen(id_to_detach));
 341         cprintf("%d %s detached from your account.\n", CIT_OK, id_to_detach);
 342 }
 343
 344
 345 /*
 346  * Attempt to auto-create a new Citadel account using the nickname from Attribute Exchange
 347  */
 348 int openid_create_user_via_ax(StrBuf *claimed_id, HashList *sreg_keys)
 349 {
 350         char *nickname = NULL;
 351         char *firstname = NULL;
 352         char *lastname = NULL;
 353         char new_password[32];
 354         long len;
 355         const char *Key;
 356         void *Value;
 357
 358         if (CtdlGetConfigInt("c_auth_mode") != AUTHMODE_NATIVE) return(1);
 359         if (CtdlGetConfigInt("c_disable_newu")) return(2);
 360         if (CC->logged_in) return(3);
 361
 362         HashPos *HashPos = GetNewHashPos(sreg_keys, 0);
 363         while (GetNextHashPos(sreg_keys, HashPos, &len, &Key, &Value) != 0) {
 364                 syslog(LOG_DEBUG, "openid: %s = %s", Key, (char *)Value);
 365
 366                 if (cbmstrcasestr(Key, "value.nickname") != NULL) {
 367                         nickname = (char *)Value;
 368                 }
 369                 else if ( (nickname == NULL) && (cbmstrcasestr(Key, "value.nickname") != NULL)) {
 370                         nickname = (char *)Value;
 371                 }
 372                 else if (cbmstrcasestr(Key, "value.firstname") != NULL) {
 373                         firstname = (char *)Value;
 374                 }
 375                 else if (cbmstrcasestr(Key, "value.lastname") != NULL) {
 376                         lastname = (char *)Value;
 377                 }
 378
 379         }
 380         DeleteHashPos(&HashPos);
 381
 382         if (nickname == NULL) {
 383                 if ((firstname != NULL) || (lastname != NULL)) {
 384                         char fullname[1024] = "";
 385                         if (firstname) strcpy(fullname, firstname);
 386                         if (firstname && lastname) strcat(fullname, " ");
 387                         if (lastname) strcat(fullname, lastname);
 388                         nickname = fullname;
 389                 }
 390         }
 391
 392         if (nickname == NULL) {
 393                 return(4);
 394         }
 395         syslog(LOG_DEBUG, "openid: the desired account name is <%s>", nickname);
 396
 397         if (!CtdlGetUser(&CC->user, nickname)) {
 398                 syslog(LOG_DEBUG, "openid: <%s> is already taken by another user.", nickname);
 399                 memset(&CC->user, 0, sizeof(struct ctdluser));
 400                 return(5);
 401         }
 402
 403         /* The desired account name is available.  Create the account and log it in! */
 404         if (create_user(nickname, CREATE_USER_BECOME_USER, NATIVE_AUTH_UID)) return(6);
 405
 406         /* Generate a random password.
 407          * The user doesn't care what the password is since he is using OpenID.
 408          */
 409         snprintf(new_password, sizeof new_password, "%08lx%08lx", random(), random());
 410         CtdlSetPassword(new_password);
 411
 412         /* Now attach the verified OpenID to this account. */
 413         attach_extauth(&CC->user, claimed_id);
 414
 415         return(0);
 416 }
 417
 418
 419 /*
 420  * If a user account exists which is associated with the Claimed ID, log it in and return zero.
 421  * Otherwise it returns nonzero.
 422  */
 423 int login_via_extauth(StrBuf *claimed_id)
 424 {
 425         struct cdbdata *cdboi;
 426         long usernum = 0;
 427
 428         cdboi = cdb_fetch(CDB_EXTAUTH, ChrPtr(claimed_id), StrLength(claimed_id));
 429         if (cdboi == NULL) {
 430                 return(-1);
 431         }
 432
 433         memcpy(&usernum, cdboi->ptr, sizeof(long));
 434         cdb_free(cdboi);
 435
 436         if (!CtdlGetUserByNumber(&CC->user, usernum)) {
 437                 /* Now become the user we just created */
 438                 safestrncpy(CC->curr_user, CC->user.fullname, sizeof CC->curr_user);
 439                 do_login();
 440                 return(0);
 441         }
 442         else {
 443                 memset(&CC->user, 0, sizeof(struct ctdluser));
 444                 return(-1);
 445         }
 446 }
 447
 448
 449
 450
 451 /**************************************************************************/
 452 /*                                                                        */
 453 /* Functions in this section handle OpenID protocol                       */
 454 /*                                                                        */
 455 /**************************************************************************/
 456
 457
 458 /*
 459  * Locate a <link> tag and, given its 'rel=' parameter, return its 'href' parameter
 460  */
 461 void extract_link(StrBuf *target_buf, const char *rel, long repllen, StrBuf *source_buf)
 462 {
 463         int i;
 464         const char *ptr;
 465         const char *href_start = NULL;
 466         const char *href_end = NULL;
 467         const char *link_tag_start = NULL;
 468         const char *link_tag_end = NULL;
 469         const char *rel_start = NULL;
 470         const char *rel_end = NULL;
 471
 472         if (!target_buf) return;
 473         if (!rel) return;
 474         if (!source_buf) return;
 475
 476         ptr = ChrPtr(source_buf);
 477
 478         FlushStrBuf(target_buf);
 479         while (ptr = cbmstrcasestr(ptr, "<link"), ptr != NULL) {
 480
 481                 link_tag_start = ptr;
 482                 link_tag_end = strchr(ptr, '>');
 483                 if (link_tag_end == NULL)
 484                         break;
 485                 for (i=0; i < 1; i++ ){
 486                         rel_start = cbmstrcasestr(link_tag_start, "rel=");
 487                         if ((rel_start == NULL) ||
 488                             (rel_start > link_tag_end))
 489                                 continue;
 490
 491                         rel_start = strchr(rel_start, '\"');
 492                         if ((rel_start == NULL) ||
 493                             (rel_start > link_tag_end))
 494                                 continue;
 495                         ++rel_start;
 496                         rel_end = strchr(rel_start, '\"');
 497                         if ((rel_end == NULL) ||
 498                             (rel_end == rel_start) ||
 499                             (rel_end >= link_tag_end) )
 500                                 continue;
 501                         if (strncasecmp(rel, rel_start, repllen)!= 0)
 502                                 continue; /* didn't match? never mind... */
 503
 504                         href_start = cbmstrcasestr(link_tag_start, "href=");
 505                         if ((href_start == NULL) ||
 506                             (href_start >= link_tag_end))
 507                                 continue;
 508                         href_start = strchr(href_start, '\"');
 509                         if ((href_start == NULL) |
 510                             (href_start >= link_tag_end))
 511                                 continue;
 512                         ++href_start;
 513                         href_end = strchr(href_start, '\"');
 514                         if ((href_end == NULL) ||
 515                             (href_end == href_start) ||
 516                             (href_start >= link_tag_end))
 517                                 continue;
 518                         StrBufPlain(target_buf, href_start, href_end - href_start);
 519                 }
 520                 ptr = link_tag_end;
 521         }
 522 }
 523
 524
 525 /*
 526  * Wrapper for curl_easy_init() that includes the options common to all calls
 527  * used in this module.
 528  */
 529 CURL *ctdl_openid_curl_easy_init(char *errmsg) {
 530         CURL *curl;
 531
 532         curl = curl_easy_init();
 533         if (!curl) {
 534                 return(curl);
 535         }
 536
 537         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0);
 538         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0);
 539
 540         if (errmsg) {
 541                 curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, errmsg);
 542         }
 543         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
 544 #ifdef CURLOPT_HTTP_CONTENT_DECODING
 545         curl_easy_setopt(curl, CURLOPT_HTTP_CONTENT_DECODING, 1);
 546         curl_easy_setopt(curl, CURLOPT_ENCODING, "");
 547 #endif
 548         curl_easy_setopt(curl, CURLOPT_USERAGENT, CITADEL);
 549         curl_easy_setopt(curl, CURLOPT_TIMEOUT, 30);            /* die after 30 seconds */
 550
 551         if (
 552                 (!IsEmptyStr(CtdlGetConfigStr("c_ip_addr")))
 553                 && (strcmp(CtdlGetConfigStr("c_ip_addr"), "*"))
 554                 && (strcmp(CtdlGetConfigStr("c_ip_addr"), "::"))
 555                 && (strcmp(CtdlGetConfigStr("c_ip_addr"), "0.0.0.0"))
 556         ) {
 557                 curl_easy_setopt(curl, CURLOPT_INTERFACE, CtdlGetConfigStr("c_ip_addr"));
 558         }
 559
 560         return(curl);
 561 }
 562
 563
 564 struct xrds {
 565         StrBuf *CharData;
 566         int nesting_level;
 567         int in_xrd;
 568         int current_service_priority;
 569         int selected_service_priority;
 570         StrBuf *current_service_uri;
 571         StrBuf *selected_service_uri;
 572         int current_service_is_oid2auth;
 573 };
 574
 575
 576 void xrds_xml_start(void *data, const char *supplied_el, const char **attr) {
 577         struct xrds *xrds = (struct xrds *) data;
 578         int i;
 579
 580         ++xrds->nesting_level;
 581
 582         if (!strcasecmp(supplied_el, "XRD")) {
 583                 ++xrds->in_xrd;
 584         }
 585
 586         else if (!strcasecmp(supplied_el, "service")) {
 587                 xrds->current_service_priority = 0;
 588                 xrds->current_service_is_oid2auth = 0;
 589                 for (i=0; attr[i] != NULL; i+=2) {
 590                         if (!strcasecmp(attr[i], "priority")) {
 591                                 xrds->current_service_priority = atoi(attr[i+1]);
 592                         }
 593                 }
 594         }
 595
 596         FlushStrBuf(xrds->CharData);
 597 }
 598
 599
 600 void xrds_xml_end(void *data, const char *supplied_el) {
 601         struct xrds *xrds = (struct xrds *) data;
 602
 603         --xrds->nesting_level;
 604
 605         if (!strcasecmp(supplied_el, "XRD")) {
 606                 --xrds->in_xrd;
 607         }
 608
 609         else if (!strcasecmp(supplied_el, "type")) {
 610                 if (    (xrds->in_xrd)
 611                         && (!strcasecmp(ChrPtr(xrds->CharData), "http://specs.openid.net/auth/2.0/server"))
 612                 ) {
 613                         xrds->current_service_is_oid2auth = 1;
 614                 }
 615                 if (    (xrds->in_xrd)
 616                         && (!strcasecmp(ChrPtr(xrds->CharData), "http://specs.openid.net/auth/2.0/signon"))
 617                 ) {
 618                         xrds->current_service_is_oid2auth = 1;
 619                         /* FIXME in this case, the Claimed ID should be considered immutable */
 620                 }
 621         }
 622
 623         else if (!strcasecmp(supplied_el, "uri")) {
 624                 if (xrds->in_xrd) {
 625                         FlushStrBuf(xrds->current_service_uri);
 626                         StrBufAppendBuf(xrds->current_service_uri, xrds->CharData, 0);
 627                 }
 628         }
 629
 630         else if (!strcasecmp(supplied_el, "service")) {
 631                 if (    (xrds->in_xrd)
 632                         && (xrds->current_service_priority < xrds->selected_service_priority)
 633                         && (xrds->current_service_is_oid2auth)
 634                 ) {
 635                         xrds->selected_service_priority = xrds->current_service_priority;
 636                         FlushStrBuf(xrds->selected_service_uri);
 637                         StrBufAppendBuf(xrds->selected_service_uri, xrds->current_service_uri, 0);
 638                 }
 639
 640         }
 641
 642         FlushStrBuf(xrds->CharData);
 643 }
 644
 645
 646 void xrds_xml_chardata(void *data, const XML_Char *s, int len) {
 647         struct xrds *xrds = (struct xrds *) data;
 648
 649         StrBufAppendBufPlain (xrds->CharData, s, len, 0);
 650 }
 651
 652
 653 /*
 654  * Parse an XRDS document.
 655  * If an OpenID Provider URL is discovered, op_url to that value and return nonzero.
 656  * If nothing useful happened, return 0.
 657  */
 658 int parse_xrds_document(StrBuf *ReplyBuf) {
 659         ctdl_openid *oiddata = (ctdl_openid *) CC->openid_data;
 660         struct xrds xrds;
 661         int return_value = 0;
 662
 663         memset(&xrds, 0, sizeof (struct xrds));
 664         xrds.selected_service_priority = INT_MAX;
 665         xrds.CharData = NewStrBuf();
 666         xrds.current_service_uri = NewStrBuf();
 667         xrds.selected_service_uri = NewStrBuf();
 668         XML_Parser xp = XML_ParserCreate(NULL);
 669         if (xp) {
 670                 XML_SetUserData(xp, &xrds);
 671                 XML_SetElementHandler(xp, xrds_xml_start, xrds_xml_end);
 672                 XML_SetCharacterDataHandler(xp, xrds_xml_chardata);
 673                 XML_Parse(xp, ChrPtr(ReplyBuf), StrLength(ReplyBuf), 0);
 674                 XML_Parse(xp, "", 0, 1);
 675                 XML_ParserFree(xp);
 676         }
 677         else {
 678                 syslog(LOG_ERR, "openid: cannot create XML parser");
 679         }
 680
 681         if (xrds.selected_service_priority < INT_MAX) {
 682                 if (oiddata->op_url == NULL) {
 683                         oiddata->op_url = NewStrBuf();
 684                 }
 685                 FlushStrBuf(oiddata->op_url);
 686                 StrBufAppendBuf(oiddata->op_url, xrds.selected_service_uri, 0);
 687                 return_value = openid_disco_xrds;
 688         }
 689
 690         FreeStrBuf(&xrds.CharData);
 691         FreeStrBuf(&xrds.current_service_uri);
 692         FreeStrBuf(&xrds.selected_service_uri);
 693
 694         return(return_value);
 695 }
 696
 697
 698 /*
 699  * Callback function for perform_openid2_discovery()
 700  * We're interested in the X-XRDS-Location: header.
 701  */
 702 size_t yadis_headerfunction(void *ptr, size_t size, size_t nmemb, void *userdata) {
 703         char hdr[1024];
 704         StrBuf **x_xrds_location = (StrBuf **) userdata;
 705
 706         memcpy(hdr, ptr, (size*nmemb));
 707         hdr[size*nmemb] = 0;
 708
 709         if (!strncasecmp(hdr, "X-XRDS-Location:", 16)) {
 710                 *x_xrds_location = NewStrBufPlain(&hdr[16], ((size*nmemb)-16));
 711                 StrBufTrim(*x_xrds_location);
 712         }
 713
 714         return(size * nmemb);
 715 }
 716
 717
 718 /* Attempt to perform Yadis discovery as specified in Yadis 1.0 section 6.2.5.
 719  *
 720  * If Yadis fails, we then attempt HTML discovery using the same document.
 721  *
 722  * If successful, returns nonzero and calls parse_xrds_document() to act upon the received data.
 723  * If fails, returns 0 and does nothing else.
 724  */
 725 int perform_openid2_discovery(StrBuf *SuppliedURL) {
 726         ctdl_openid *oiddata = (ctdl_openid *) CC->openid_data;
 727         int docbytes = (-1);
 728         StrBuf *ReplyBuf = NULL;
 729         int return_value = 0;
 730         CURL *curl;
 731         CURLcode result;
 732         char errmsg[1024] = "";
 733         struct curl_slist *my_headers = NULL;
 734         StrBuf *x_xrds_location = NULL;
 735
 736         if (!SuppliedURL) return(0);
 737         syslog(LOG_DEBUG, "openid: perform_openid2_discovery(%s)", ChrPtr(SuppliedURL));
 738         if (StrLength(SuppliedURL) == 0) return(0);
 739
 740         ReplyBuf = NewStrBuf();
 741         if (!ReplyBuf) return(0);
 742
 743         curl = ctdl_openid_curl_easy_init(errmsg);
 744         if (!curl) return(0);
 745
 746         curl_easy_setopt(curl, CURLOPT_URL, ChrPtr(SuppliedURL));
 747         curl_easy_setopt(curl, CURLOPT_WRITEDATA, ReplyBuf);
 748         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, CurlFillStrBuf_callback);
 749
 750         my_headers = curl_slist_append(my_headers, "Accept:");  /* disable the default Accept: header */
 751         my_headers = curl_slist_append(my_headers, "Accept: application/xrds+xml");
 752         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, my_headers);
 753
 754         curl_easy_setopt(curl, CURLOPT_WRITEHEADER, &x_xrds_location);
 755         curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, yadis_headerfunction);
 756
 757         result = curl_easy_perform(curl);
 758         if (result) {
 759                 syslog(LOG_DEBUG, "openid: libcurl error %d: %s", result, errmsg);
 760         }
 761         curl_slist_free_all(my_headers);
 762         curl_easy_cleanup(curl);
 763         docbytes = StrLength(ReplyBuf);
 764
 765         /*
 766          * The response from the server will be one of:
 767          *
 768          * Option 1: An HTML document with a <head> element that includes a <meta> element with http-equiv
 769          * attribute, X-XRDS-Location,
 770          *
 771          * Does any provider actually do this?  If so then we will implement it in the future.
 772          */
 773
 774         /*
 775          * Option 2: HTTP response-headers that include an X-XRDS-Location response-header,
 776          *           together with a document.
 777          * Option 3: HTTP response-headers only, which MAY include an X-XRDS-Location response-header,
 778          *           a contenttype response-header specifying MIME media type,
 779          *           application/xrds+xml, or both.
 780          *
 781          * If the X-XRDS-Location header was delivered, we know about it at this point...
 782          */
 783         if (    (x_xrds_location)
 784                 && (strcmp(ChrPtr(x_xrds_location), ChrPtr(SuppliedURL)))
 785         ) {
 786                 syslog(LOG_DEBUG, "openid: X-XRDS-Location: %s ... recursing!", ChrPtr(x_xrds_location));
 787                 return_value = perform_openid2_discovery(x_xrds_location);
 788                 FreeStrBuf(&x_xrds_location);
 789         }
 790
 791         /*
 792          * Option 4: the returned web page may *be* an XRDS document.  Try to parse it.
 793          */
 794         if ( (return_value == 0) && (docbytes >= 0)) {
 795                 return_value = parse_xrds_document(ReplyBuf);
 796         }
 797
 798         /*
 799          * Option 5: if all else fails, attempt HTML based discovery.
 800          */
 801         if ( (return_value == 0) && (docbytes >= 0)) {
 802                 if (oiddata->op_url == NULL) {
 803                         oiddata->op_url = NewStrBuf();
 804                 }
 805                 extract_link(oiddata->op_url, HKEY("openid2.provider"), ReplyBuf);
 806                 if (StrLength(oiddata->op_url) > 0) {
 807                         return_value = openid_disco_html;
 808                 }
 809         }
 810
 811         if (ReplyBuf != NULL) {
 812                 FreeStrBuf(&ReplyBuf);
 813         }
 814         return(return_value);
 815 }
 816
 817
 818 /*
 819  * Setup an OpenID authentication
 820  */
 821 void cmd_oids(char *argbuf) {
 822         struct CitContext *CCC = CC;    /* CachedCitContext - performance boost */
 823         const char *Pos = NULL;
 824         StrBuf *ArgBuf = NULL;
 825         StrBuf *ReplyBuf = NULL;
 826         StrBuf *return_to = NULL;
 827         StrBuf *RedirectUrl = NULL;
 828         ctdl_openid *oiddata;
 829         int discovery_succeeded = 0;
 830
 831         if (CtdlGetConfigInt("c_disable_newu"))
 832         {
 833                 cprintf("%d this system does not support openid.\n",
 834                         ERROR + CMD_NOT_SUPPORTED);
 835                 return;
 836         }
 837         Free_ctdl_openid ((ctdl_openid**)&CCC->openid_data);
 838
 839         CCC->openid_data = oiddata = malloc(sizeof(ctdl_openid));
 840         if (oiddata == NULL) {
 841                 syslog(LOG_ERR, "openid: malloc() failed: %m");
 842                 cprintf("%d malloc failed\n", ERROR + INTERNAL_ERROR);
 843                 return;
 844         }
 845         memset(oiddata, 0, sizeof(ctdl_openid));
 846
 847         ArgBuf = NewStrBufPlain(argbuf, -1);
 848
 849         oiddata->verified = 0;
 850         oiddata->claimed_id = NewStrBufPlain(NULL, StrLength(ArgBuf));
 851         return_to = NewStrBufPlain(NULL, StrLength(ArgBuf));
 852
 853         StrBufExtract_NextToken(oiddata->claimed_id, ArgBuf, &Pos, '|');
 854         StrBufExtract_NextToken(return_to, ArgBuf, &Pos, '|');
 855
 856         syslog(LOG_DEBUG, "openid: user-Supplied Identifier is: %s", ChrPtr(oiddata->claimed_id));
 857
 858         /********** OpenID 2.0 section 7.3 - Discovery **********/
 859
 860         /* Section 7.3.1 says we have to attempt XRI based discovery.
 861          * No one is using this, no one is asking for it, no one wants it.
 862          * So we're not even going to bother attempting this mode.
 863          */
 864
 865         /* Attempt section 7.3.2 (Yadis discovery) and section 7.3.3 (HTML discovery);
 866          */
 867         discovery_succeeded = perform_openid2_discovery(oiddata->claimed_id);
 868
 869         if (discovery_succeeded == 0) {
 870                 cprintf("%d There is no OpenID identity provider at this location.\n", ERROR);
 871         }
 872
 873         else {
 874                 /*
 875                  * If we get to this point we are in possession of a valid OpenID Provider URL.
 876                  */
 877                 syslog(LOG_DEBUG, "openid: OP URI '%s' discovered using method %d",
 878                         ChrPtr(oiddata->op_url),
 879                         discovery_succeeded
 880                 );
 881
 882                 /* We have to "normalize" our Claimed ID otherwise it will cause some OP's to barf */
 883                 if (cbmstrcasestr(ChrPtr(oiddata->claimed_id), "://") == NULL) {
 884                         StrBuf *cid = oiddata->claimed_id;
 885                         oiddata->claimed_id = NewStrBufPlain(HKEY("http://"));
 886                         StrBufAppendBuf(oiddata->claimed_id, cid, 0);
 887                         FreeStrBuf(&cid);
 888                 }
 889
 890                 /*
 891                  * OpenID 2.0 section 9: request authentication
 892                  * Assemble a URL to which the user-agent will be redirected.
 893                  */
 894
 895                 RedirectUrl = NewStrBufDup(oiddata->op_url);
 896
 897                 StrBufAppendBufPlain(RedirectUrl, HKEY("?openid.ns="), 0);
 898                 StrBufUrlescAppend(RedirectUrl, NULL, "http://specs.openid.net/auth/2.0");
 899
 900                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.mode=checkid_setup"), 0);
 901
 902                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.claimed_id="), 0);
 903                 StrBufUrlescAppend(RedirectUrl, oiddata->claimed_id, NULL);
 904
 905                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.identity="), 0);
 906                 StrBufUrlescAppend(RedirectUrl, oiddata->claimed_id, NULL);
 907
 908                 /* return_to tells the provider how to complete the round trip back to our site */
 909                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.return_to="), 0);
 910                 StrBufUrlescAppend(RedirectUrl, return_to, NULL);
 911
 912                 /* Attribute Exchange
 913                  * See:
 914                  *      http://openid.net/specs/openid-attribute-exchange-1_0.html
 915                  *      http://code.google.com/apis/accounts/docs/OpenID.html#endpoint
 916                  *      http://test-id.net/OP/AXFetch.aspx
 917                  */
 918
 919                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.ns.ax="), 0);
 920                 StrBufUrlescAppend(RedirectUrl, NULL, "http://openid.net/srv/ax/1.0");
 921
 922                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.ax.mode=fetch_request"), 0);
 923
 924                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.ax.required=firstname,lastname,friendly,nickname"), 0);
 925
 926                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.ax.type.firstname="), 0);
 927                 StrBufUrlescAppend(RedirectUrl, NULL, "http://axschema.org/namePerson/first");
 928
 929                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.ax.type.lastname="), 0);
 930                 StrBufUrlescAppend(RedirectUrl, NULL, "http://axschema.org/namePerson/last");
 931
 932                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.ax.type.friendly="), 0);
 933                 StrBufUrlescAppend(RedirectUrl, NULL, "http://axschema.org/namePerson/friendly");
 934
 935                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.ax.type.nickname="), 0);
 936                 StrBufUrlescAppend(RedirectUrl, NULL, "http://axschema.org/namePerson/nickname");
 937
 938                 syslog(LOG_DEBUG, "openid: redirecting client to %s", ChrPtr(RedirectUrl));
 939                 cprintf("%d %s\n", CIT_OK, ChrPtr(RedirectUrl));
 940         }
 941
 942         FreeStrBuf(&ArgBuf);
 943         FreeStrBuf(&ReplyBuf);
 944         FreeStrBuf(&return_to);
 945         FreeStrBuf(&RedirectUrl);
 946 }
 947
 948
 949 /*
 950  * Finalize an OpenID authentication
 951  */
 952 void cmd_oidf(char *argbuf) {
 953         long len;
 954         char buf[2048];
 955         char thiskey[1024];
 956         char thisdata[1024];
 957         HashList *keys = NULL;
 958         const char *Key;
 959         void *Value;
 960         ctdl_openid *oiddata = (ctdl_openid *) CC->openid_data;
 961
 962         if (CtdlGetConfigInt("c_disable_newu"))
 963         {
 964                 cprintf("%d this system does not support openid.\n",
 965                         ERROR + CMD_NOT_SUPPORTED);
 966                 return;
 967         }
 968         if (oiddata == NULL) {
 969                 cprintf("%d run OIDS first.\n", ERROR + INTERNAL_ERROR);
 970                 return;
 971         }
 972         if (StrLength(oiddata->op_url) == 0){
 973                 cprintf("%d No OpenID Endpoint URL has been obtained.\n", ERROR + ILLEGAL_VALUE);
 974                 return;
 975         }
 976         keys = NewHash(1, NULL);
 977         if (!keys) {
 978                 cprintf("%d NewHash() failed\n", ERROR + INTERNAL_ERROR);
 979                 return;
 980         }
 981         cprintf("%d Transmit OpenID data now\n", START_CHAT_MODE);
 982
 983         while (client_getln(buf, sizeof buf), strcmp(buf, "000")) {
 984                 len = extract_token(thiskey, buf, 0, '|', sizeof thiskey);
 985                 if (len < 0) {
 986                         len = sizeof(thiskey) - 1;
 987                 }
 988                 extract_token(thisdata, buf, 1, '|', sizeof thisdata);
 989                 Put(keys, thiskey, len, strdup(thisdata), NULL);
 990         }
 991
 992         /* Check to see if this is a correct response.
 993          * Start with verified=1 but then set it to 0 if anything looks wrong.
 994          */
 995         oiddata->verified = 1;
 996
 997         char *openid_ns = NULL;
 998         if (    (!GetHash(keys, "ns", 2, (void *) &openid_ns))
 999                 || (strcasecmp(openid_ns, "http://specs.openid.net/auth/2.0"))
1000         ) {
1001                 syslog(LOG_DEBUG, "openid: this is not an an OpenID assertion");
1002                 oiddata->verified = 0;
1003         }
1004
1005         char *openid_mode = NULL;
1006         if (    (!GetHash(keys, "mode", 4, (void *) &openid_mode))
1007                 || (strcasecmp(openid_mode, "id_res"))
1008         ) {
1009                 oiddata->verified = 0;
1010         }
1011
1012         char *openid_claimed_id = NULL;
1013         if (GetHash(keys, "claimed_id", 10, (void *) &openid_claimed_id)) {
1014                 FreeStrBuf(&oiddata->claimed_id);
1015                 oiddata->claimed_id = NewStrBufPlain(openid_claimed_id, -1);
1016                 syslog(LOG_DEBUG, "openid: provider is asserting the Claimed ID '%s'", ChrPtr(oiddata->claimed_id));
1017         }
1018
1019         /* Validate the assertion against the server */
1020         syslog(LOG_DEBUG, "openid: validating...");
1021
1022         CURL *curl;
1023         CURLcode res;
1024         struct curl_httppost *formpost = NULL;
1025         struct curl_httppost *lastptr = NULL;
1026         char errmsg[1024] = "";
1027         StrBuf *ReplyBuf = NewStrBuf();
1028
1029         curl_formadd(&formpost, &lastptr,
1030                 CURLFORM_COPYNAME,      "openid.mode",
1031                 CURLFORM_COPYCONTENTS,  "check_authentication",
1032                 CURLFORM_END
1033         );
1034
1035         HashPos *HashPos = GetNewHashPos(keys, 0);
1036         while (GetNextHashPos(keys, HashPos, &len, &Key, &Value) != 0) {
1037                 if (strcasecmp(Key, "mode")) {
1038                         char k_o_keyname[1024];
1039                         snprintf(k_o_keyname, sizeof k_o_keyname, "openid.%s", (const char *)Key);
1040                         curl_formadd(&formpost, &lastptr,
1041                                 CURLFORM_COPYNAME,      k_o_keyname,
1042                                 CURLFORM_COPYCONTENTS,  (char *)Value,
1043                                 CURLFORM_END
1044                         );
1045                 }
1046         }
1047         DeleteHashPos(&HashPos);
1048
1049         curl = ctdl_openid_curl_easy_init(errmsg);
1050         curl_easy_setopt(curl, CURLOPT_URL, ChrPtr(oiddata->op_url));
1051         curl_easy_setopt(curl, CURLOPT_WRITEDATA, ReplyBuf);
1052         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, CurlFillStrBuf_callback);
1053         curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost);
1054
1055         res = curl_easy_perform(curl);
1056         if (res) {
1057                 syslog(LOG_DEBUG, "openid: cmd_oidf() libcurl error %d: %s", res, errmsg);
1058                 oiddata->verified = 0;
1059         }
1060         curl_easy_cleanup(curl);
1061         curl_formfree(formpost);
1062
1063         if (cbmstrcasestr(ChrPtr(ReplyBuf), "is_valid:true") == NULL) {
1064                 oiddata->verified = 0;
1065         }
1066         FreeStrBuf(&ReplyBuf);
1067
1068         syslog(LOG_DEBUG, "openid: authentication %s", (oiddata->verified ? "succeeded" : "failed") );
1069
1070         /* Respond to the client */
1071
1072         if (oiddata->verified) {
1073
1074                 /* If we were already logged in, attach the OpenID to the user's account */
1075                 if (CC->logged_in) {
1076                         if (attach_extauth(&CC->user, oiddata->claimed_id) == 0) {
1077                                 cprintf("attach\n");
1078                                 syslog(LOG_DEBUG, "openid: attach succeeded");
1079                         }
1080                         else {
1081                                 cprintf("fail\n");
1082                                 syslog(LOG_DEBUG, "openid: attach failed");
1083                         }
1084                 }
1085
1086                 /* Otherwise, a user is attempting to log in using the verified OpenID */
1087                 else {
1088                         /*
1089                          * Existing user who has claimed this OpenID?
1090                          *
1091                          * Note: if you think that sending the password back over the wire is insecure,
1092                          * check your assumptions.  If someone has successfully asserted an OpenID that
1093                          * is associated with the account, they already have password equivalency and can
1094                          * login, so they could just as easily change the password, etc.
1095                          */
1096                         if (login_via_extauth(oiddata->claimed_id) == 0) {
1097                                 cprintf("authenticate\n%s\n%s\n", CC->user.fullname, CC->user.password);
1098                                 logged_in_response();
1099                                 syslog(LOG_DEBUG, "openid: logged in using previously claimed OpenID");
1100                         }
1101
1102                         /*
1103                          * If this system does not allow self-service new user registration, the
1104                          * remaining modes do not apply, so fail here and now.
1105                          */
1106                         else if (CtdlGetConfigInt("c_disable_newu")) {
1107                                 cprintf("fail\n");
1108                                 syslog(LOG_DEBUG, "openid: creating user failed due to local policy");
1109                         }
1110
1111                         /*
1112                          * New user whose OpenID is verified and Attribute Exchange gave us a name?
1113                          */
1114                         else if (openid_create_user_via_ax(oiddata->claimed_id, keys) == 0) {
1115                                 cprintf("authenticate\n%s\n%s\n", CC->user.fullname, CC->user.password);
1116                                 logged_in_response();
1117                                 syslog(LOG_DEBUG, "openid: successfully auto-created new user");
1118                         }
1119
1120                         /*
1121                          * OpenID is verified, but the desired username either was not specified or
1122                          * conflicts with an existing user.  Manual account creation is required.
1123                          */
1124                         else {
1125                                 char *desired_name = NULL;
1126                                 cprintf("verify_only\n");
1127                                 cprintf("%s\n", ChrPtr(oiddata->claimed_id));
1128                                 if (GetHash(keys, "sreg.nickname", 13, (void *) &desired_name)) {
1129                                         cprintf("%s\n", desired_name);
1130                                 }
1131                                 else {
1132                                         cprintf("\n");
1133                                 }
1134                                 syslog(LOG_DEBUG, "openid: the desired display name is already taken.");
1135                         }
1136                 }
1137         }
1138         else {
1139                 cprintf("fail\n");
1140         }
1141         cprintf("000\n");
1142
1143         if (oiddata->sreg_keys != NULL) {
1144                 DeleteHash(&oiddata->sreg_keys);
1145                 oiddata->sreg_keys = NULL;
1146         }
1147         oiddata->sreg_keys = keys;
1148 }
1149
1150
1151
1152 /**************************************************************************/
1153 /*                                                                        */
1154 /* Functions in this section handle module initialization and shutdown    */
1155 /*                                                                        */
1156 /**************************************************************************/
1157
1158
1159
1160
1161 CTDL_MODULE_INIT(openid_rp)
1162 {
1163         if (!threading) {
1164
1165                 /* Only enable the OpenID command set when native mode authentication is in use. */
1166                 if (CtdlGetConfigInt("c_auth_mode") == AUTHMODE_NATIVE) {
1167                         CtdlRegisterProtoHook(cmd_oids, "OIDS", "Setup OpenID authentication");
1168                         CtdlRegisterProtoHook(cmd_oidf, "OIDF", "Finalize OpenID authentication");
1169                         CtdlRegisterProtoHook(cmd_oidl, "OIDL", "List OpenIDs associated with an account");
1170                         CtdlRegisterProtoHook(cmd_oidd, "OIDD", "Detach an OpenID from an account");
1171                         CtdlRegisterProtoHook(cmd_oidc, "OIDC", "Create new user after validating OpenID");
1172                         CtdlRegisterProtoHook(cmd_oida, "OIDA", "List all OpenIDs in the database");
1173                 }
1174                 CtdlRegisterSessionHook(openid_cleanup_function, EVT_LOGOUT, PRIO_LOGOUT + 10);
1175                 CtdlRegisterUserHook(extauth_purge, EVT_PURGEUSER);
1176                 openid_level_supported = 1;     /* This module supports OpenID 1.0 only */
1177         }
1178
1179         /* return our module name for the log */
1180         return "openid_rp";
1181 }