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) 2007-2011 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, "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 OpenID to a Citadel account
 116  */
 117 int attach_openid(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 OpenID is already in the database */
 129
 130         cdboi = cdb_fetch(CDB_OPENID, 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, "%s already associated; no action is taken", ChrPtr(claimed_id));
 137                         return(0);
 138                 }
 139                 else {
 140                         syslog(LOG_INFO, "%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_OPENID, ChrPtr(claimed_id), StrLength(claimed_id), data, data_len);
 154         free(data);
 155
 156         snprintf(buf, sizeof buf, "User <%s> (#%ld) has claimed the OpenID URL %s\n",
 157                  who->fullname, who->usernum, ChrPtr(claimed_id));
 158         CtdlAideMessage(buf, "OpenID claim");
 159         syslog(LOG_INFO, "%s", buf);
 160         return(0);
 161 }
 162
 163
 164
 165 /*
 166  * When a user is being deleted, we have to delete any OpenID associations
 167  */
 168 void openid_purge(struct ctdluser *usbuf) {
 169         struct cdbdata *cdboi;
 170         HashList *keys = NULL;
 171         HashPos *HashPos;
 172         char *deleteme = NULL;
 173         long len;
 174         void *Value;
 175         const char *Key;
 176         long usernum = 0L;
 177
 178         keys = NewHash(1, NULL);
 179         if (!keys) return;
 180
 181         cdb_rewind(CDB_OPENID);
 182         while (cdboi = cdb_next_item(CDB_OPENID), cdboi != NULL) {
 183                 if (cdboi->len > sizeof(long)) {
 184                         memcpy(&usernum, cdboi->ptr, sizeof(long));
 185                         if (usernum == usbuf->usernum) {
 186                                 deleteme = strdup(cdboi->ptr + sizeof(long)),
 187                                 Put(keys, deleteme, strlen(deleteme), deleteme, NULL);
 188                         }
 189                 }
 190                 cdb_free(cdboi);
 191         }
 192
 193         /* Go through the hash list, deleting keys we stored in it */
 194
 195         HashPos = GetNewHashPos(keys, 0);
 196         while (GetNextHashPos(keys, HashPos, &len, &Key, &Value)!=0)
 197         {
 198                 syslog(LOG_DEBUG, "Deleting associated OpenID <%s>", (char*)Value);
 199                 cdb_delete(CDB_OPENID, Value, strlen(Value));
 200                 /* note: don't free(Value) -- deleting the hash list will handle this for us */
 201         }
 202         DeleteHashPos(&HashPos);
 203         DeleteHash(&keys);
 204 }
 205
 206
 207 /*
 208  * List the OpenIDs associated with the currently logged in account
 209  */
 210 void cmd_oidl(char *argbuf) {
 211         struct cdbdata *cdboi;
 212         long usernum = 0L;
 213
 214         if (CtdlAccessCheck(ac_logged_in)) return;
 215         cdb_rewind(CDB_OPENID);
 216         cprintf("%d Associated OpenIDs:\n", LISTING_FOLLOWS);
 217
 218         while (cdboi = cdb_next_item(CDB_OPENID), cdboi != NULL) {
 219                 if (cdboi->len > sizeof(long)) {
 220                         memcpy(&usernum, cdboi->ptr, sizeof(long));
 221                         if (usernum == CC->user.usernum) {
 222                                 cprintf("%s\n", cdboi->ptr + sizeof(long));
 223                         }
 224                 }
 225                 cdb_free(cdboi);
 226         }
 227         cprintf("000\n");
 228 }
 229
 230
 231 /*
 232  * List ALL OpenIDs in the database
 233  */
 234 void cmd_oida(char *argbuf) {
 235         struct cdbdata *cdboi;
 236         long usernum;
 237         struct ctdluser usbuf;
 238
 239         if (CtdlAccessCheck(ac_aide)) return;
 240         cdb_rewind(CDB_OPENID);
 241         cprintf("%d List of all OpenIDs in the database:\n", LISTING_FOLLOWS);
 242
 243         while (cdboi = cdb_next_item(CDB_OPENID), cdboi != NULL) {
 244                 if (cdboi->len > sizeof(long)) {
 245                         memcpy(&usernum, cdboi->ptr, sizeof(long));
 246                         if (CtdlGetUserByNumber(&usbuf, usernum) != 0) {
 247                                 usbuf.fullname[0] = 0;
 248                         }
 249                         cprintf("%s|%ld|%s\n",
 250                                 cdboi->ptr + sizeof(long),
 251                                 usernum,
 252                                 usbuf.fullname
 253                         );
 254                 }
 255                 cdb_free(cdboi);
 256         }
 257         cprintf("000\n");
 258 }
 259
 260
 261 /*
 262  * Create a new user account, manually specifying the name, after successfully
 263  * verifying an OpenID (which will of course be attached to the account)
 264  */
 265 void cmd_oidc(char *argbuf) {
 266         ctdl_openid *oiddata = (ctdl_openid *) CC->openid_data;
 267
 268         if ( (!oiddata) || (!oiddata->verified) ) {
 269                 cprintf("%d You have not verified an OpenID yet.\n", ERROR);
 270                 return;
 271         }
 272
 273         /* We can make the semantics of OIDC exactly the same as NEWU, simply
 274          * by _calling_ cmd_newu() and letting it run.  Very clever!
 275          */
 276         cmd_newu(argbuf);
 277
 278         /* Now, if this logged us in, we have to attach the OpenID */
 279         if (CC->logged_in) {
 280                 attach_openid(&CC->user, oiddata->claimed_id);
 281         }
 282
 283 }
 284
 285
 286 /*
 287  * Detach an OpenID from the currently logged in account
 288  */
 289 void cmd_oidd(char *argbuf) {
 290         struct cdbdata *cdboi;
 291         char id_to_detach[1024];
 292         int this_is_mine = 0;
 293         long usernum = 0L;
 294
 295         if (CtdlAccessCheck(ac_logged_in)) return;
 296         extract_token(id_to_detach, argbuf, 0, '|', sizeof id_to_detach);
 297         if (IsEmptyStr(id_to_detach)) {
 298                 cprintf("%d An empty OpenID URL is not allowed.\n", ERROR + ILLEGAL_VALUE);
 299         }
 300
 301         cdb_rewind(CDB_OPENID);
 302         while (cdboi = cdb_next_item(CDB_OPENID), cdboi != NULL) {
 303                 if (cdboi->len > sizeof(long)) {
 304                         memcpy(&usernum, cdboi->ptr, sizeof(long));
 305                         if (usernum == CC->user.usernum) {
 306                                 this_is_mine = 1;
 307                         }
 308                 }
 309                 cdb_free(cdboi);
 310         }
 311
 312         if (!this_is_mine) {
 313                 cprintf("%d That OpenID was not found or not associated with your account.\n",
 314                         ERROR + ILLEGAL_VALUE);
 315                 return;
 316         }
 317
 318         cdb_delete(CDB_OPENID, id_to_detach, strlen(id_to_detach));
 319         cprintf("%d %s detached from your account.\n", CIT_OK, id_to_detach);
 320 }
 321
 322
 323 /*
 324  * Attempt to auto-create a new Citadel account using the nickname from Attribute Exchange
 325  */
 326 int openid_create_user_via_ax(StrBuf *claimed_id, HashList *sreg_keys)
 327 {
 328         char *desired_name = NULL;
 329         char new_password[32];
 330         long len;
 331
 332         if (config.c_auth_mode != AUTHMODE_NATIVE) return(1);
 333         if (config.c_disable_newu) return(2);
 334         if (CC->logged_in) return(3);
 335         if (!GetHash(sreg_keys, "sreg.nickname", 13, (void *) &desired_name)) return(4);
 336
 337         syslog(LOG_DEBUG, "The desired account name is <%s>", desired_name);
 338
 339         len = cutuserkey(desired_name);
 340         if (!CtdlGetUser(&CC->user, desired_name)) {
 341                 syslog(LOG_DEBUG, "<%s> is already taken by another user.", desired_name);
 342                 memset(&CC->user, 0, sizeof(struct ctdluser));
 343                 return(5);
 344         }
 345
 346         /* The desired account name is available.  Create the account and log it in! */
 347         if (create_user(desired_name, len, 1)) return(6);
 348
 349         /* Generate a random password.
 350          * The user doesn't care what the password is since he's using OpenID.
 351          */
 352         snprintf(new_password, sizeof new_password, "%08lx%08lx", random(), random());
 353         CtdlSetPassword(new_password);
 354
 355         /* Now attach the verified OpenID to this account. */
 356         attach_openid(&CC->user, claimed_id);
 357
 358         return(0);
 359 }
 360
 361
 362 /*
 363  * If a user account exists which is associated with the Claimed ID, log it in and return zero.
 364  * Otherwise it returns nonzero.
 365  */
 366 int login_via_openid(StrBuf *claimed_id)
 367 {
 368         struct cdbdata *cdboi;
 369         long usernum = 0;
 370
 371         cdboi = cdb_fetch(CDB_OPENID, ChrPtr(claimed_id), StrLength(claimed_id));
 372         if (cdboi == NULL) {
 373                 return(-1);
 374         }
 375
 376         memcpy(&usernum, cdboi->ptr, sizeof(long));
 377         cdb_free(cdboi);
 378
 379         if (!CtdlGetUserByNumber(&CC->user, usernum)) {
 380                 /* Now become the user we just created */
 381                 safestrncpy(CC->curr_user, CC->user.fullname, sizeof CC->curr_user);
 382                 do_login();
 383                 return(0);
 384         }
 385         else {
 386                 memset(&CC->user, 0, sizeof(struct ctdluser));
 387                 return(-1);
 388         }
 389 }
 390
 391
 392
 393
 394 /**************************************************************************/
 395 /*                                                                        */
 396 /* Functions in this section handle OpenID protocol                       */
 397 /*                                                                        */
 398 /**************************************************************************/
 399
 400
 401 /*
 402  * Locate a <link> tag and, given its 'rel=' parameter, return its 'href' parameter
 403  */
 404 void extract_link(StrBuf *target_buf, const char *rel, long repllen, StrBuf *source_buf)
 405 {
 406         int i;
 407         const char *ptr;
 408         const char *href_start = NULL;
 409         const char *href_end = NULL;
 410         const char *link_tag_start = NULL;
 411         const char *link_tag_end = NULL;
 412         const char *rel_start = NULL;
 413         const char *rel_end = NULL;
 414
 415         if (!target_buf) return;
 416         if (!rel) return;
 417         if (!source_buf) return;
 418
 419         ptr = ChrPtr(source_buf);
 420
 421         FlushStrBuf(target_buf);
 422         while (ptr = cbmstrcasestr(ptr, "<link"), ptr != NULL) {
 423
 424                 link_tag_start = ptr;
 425                 link_tag_end = strchr(ptr, '>');
 426                 if (link_tag_end == NULL)
 427                         break;
 428                 for (i=0; i < 1; i++ ){
 429                         rel_start = cbmstrcasestr(link_tag_start, "rel=");
 430                         if ((rel_start == NULL) ||
 431                             (rel_start > link_tag_end))
 432                                 continue;
 433
 434                         rel_start = strchr(rel_start, '\"');
 435                         if ((rel_start == NULL) ||
 436                             (rel_start > link_tag_end))
 437                                 continue;
 438                         ++rel_start;
 439                         rel_end = strchr(rel_start, '\"');
 440                         if ((rel_end == NULL) ||
 441                             (rel_end == rel_start) ||
 442                             (rel_end >= link_tag_end) )
 443                                 continue;
 444                         if (strncasecmp(rel, rel_start, repllen)!= 0)
 445                                 continue; /* didn't match? never mind... */
 446
 447                         href_start = cbmstrcasestr(link_tag_start, "href=");
 448                         if ((href_start == NULL) ||
 449                             (href_start >= link_tag_end))
 450                                 continue;
 451                         href_start = strchr(href_start, '\"');
 452                         if ((href_start == NULL) |
 453                             (href_start >= link_tag_end))
 454                                 continue;
 455                         ++href_start;
 456                         href_end = strchr(href_start, '\"');
 457                         if ((href_end == NULL) ||
 458                             (href_end == href_start) ||
 459                             (href_start >= link_tag_end))
 460                                 continue;
 461                         StrBufPlain(target_buf, href_start, href_end - href_start);
 462                 }
 463                 ptr = link_tag_end;
 464         }
 465 }
 466
 467
 468 /*
 469  * Wrapper for curl_easy_init() that includes the options common to all calls
 470  * used in this module.
 471  */
 472 CURL *ctdl_openid_curl_easy_init(char *errmsg) {
 473         CURL *curl;
 474
 475         curl = curl_easy_init();
 476         if (!curl) {
 477                 return(curl);
 478         }
 479
 480         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0);
 481         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0);
 482
 483         if (errmsg) {
 484                 curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, errmsg);
 485         }
 486         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
 487 #ifdef CURLOPT_HTTP_CONTENT_DECODING
 488         curl_easy_setopt(curl, CURLOPT_HTTP_CONTENT_DECODING, 1);
 489         curl_easy_setopt(curl, CURLOPT_ENCODING, "");
 490 #endif
 491         curl_easy_setopt(curl, CURLOPT_USERAGENT, CITADEL);
 492         curl_easy_setopt(curl, CURLOPT_TIMEOUT, 30);            /* die after 30 seconds */
 493
 494         if (
 495                 (!IsEmptyStr(config.c_ip_addr))
 496                 && (strcmp(config.c_ip_addr, "*"))
 497                 && (strcmp(config.c_ip_addr, "::"))
 498                 && (strcmp(config.c_ip_addr, "0.0.0.0"))
 499         ) {
 500                 curl_easy_setopt(curl, CURLOPT_INTERFACE, config.c_ip_addr);
 501         }
 502
 503         return(curl);
 504 }
 505
 506
 507 struct xrds {
 508         StrBuf *CharData;
 509         int nesting_level;
 510         int in_xrd;
 511         int current_service_priority;
 512         int selected_service_priority;
 513         StrBuf *current_service_uri;
 514         StrBuf *selected_service_uri;
 515         int current_service_is_oid2auth;
 516 };
 517
 518
 519 void xrds_xml_start(void *data, const char *supplied_el, const char **attr) {
 520         struct xrds *xrds = (struct xrds *) data;
 521         int i;
 522
 523         ++xrds->nesting_level;
 524
 525         if (!strcasecmp(supplied_el, "XRD")) {
 526                 ++xrds->in_xrd;
 527         }
 528
 529         else if (!strcasecmp(supplied_el, "service")) {
 530                 xrds->current_service_priority = 0;
 531                 xrds->current_service_is_oid2auth = 0;
 532                 for (i=0; attr[i] != NULL; i+=2) {
 533                         if (!strcasecmp(attr[i], "priority")) {
 534                                 xrds->current_service_priority = atoi(attr[i+1]);
 535                         }
 536                 }
 537         }
 538
 539         FlushStrBuf(xrds->CharData);
 540 }
 541
 542
 543 void xrds_xml_end(void *data, const char *supplied_el) {
 544         struct xrds *xrds = (struct xrds *) data;
 545
 546         --xrds->nesting_level;
 547
 548         if (!strcasecmp(supplied_el, "XRD")) {
 549                 --xrds->in_xrd;
 550         }
 551
 552         else if (!strcasecmp(supplied_el, "type")) {
 553                 if (    (xrds->in_xrd)
 554                         && (!strcasecmp(ChrPtr(xrds->CharData), "http://specs.openid.net/auth/2.0/server"))
 555                 ) {
 556                         xrds->current_service_is_oid2auth = 1;
 557                 }
 558                 if (    (xrds->in_xrd)
 559                         && (!strcasecmp(ChrPtr(xrds->CharData), "http://specs.openid.net/auth/2.0/signon"))
 560                 ) {
 561                         xrds->current_service_is_oid2auth = 1;
 562                         /* FIXME in this case, the Claimed ID should be considered immutable */
 563                 }
 564         }
 565
 566         else if (!strcasecmp(supplied_el, "uri")) {
 567                 if (xrds->in_xrd) {
 568                         FlushStrBuf(xrds->current_service_uri);
 569                         StrBufAppendBuf(xrds->current_service_uri, xrds->CharData, 0);
 570                 }
 571         }
 572
 573         else if (!strcasecmp(supplied_el, "service")) {
 574                 if (    (xrds->in_xrd)
 575                         && (xrds->current_service_priority < xrds->selected_service_priority)
 576                         && (xrds->current_service_is_oid2auth)
 577                 ) {
 578                         xrds->selected_service_priority = xrds->current_service_priority;
 579                         FlushStrBuf(xrds->selected_service_uri);
 580                         StrBufAppendBuf(xrds->selected_service_uri, xrds->current_service_uri, 0);
 581                 }
 582
 583         }
 584
 585         FlushStrBuf(xrds->CharData);
 586 }
 587
 588
 589 void xrds_xml_chardata(void *data, const XML_Char *s, int len) {
 590         struct xrds *xrds = (struct xrds *) data;
 591
 592         StrBufAppendBufPlain (xrds->CharData, s, len, 0);
 593 }
 594
 595
 596 /*
 597  * Parse an XRDS document.
 598  * If an OpenID Provider URL is discovered, op_url to that value and return nonzero.
 599  * If nothing useful happened, return 0.
 600  */
 601 int parse_xrds_document(StrBuf *ReplyBuf) {
 602         ctdl_openid *oiddata = (ctdl_openid *) CC->openid_data;
 603         struct xrds xrds;
 604         int return_value = 0;
 605
 606         memset(&xrds, 0, sizeof (struct xrds));
 607         xrds.selected_service_priority = INT_MAX;
 608         xrds.CharData = NewStrBuf();
 609         xrds.current_service_uri = NewStrBuf();
 610         xrds.selected_service_uri = NewStrBuf();
 611         XML_Parser xp = XML_ParserCreate(NULL);
 612         if (xp) {
 613                 XML_SetUserData(xp, &xrds);
 614                 XML_SetElementHandler(xp, xrds_xml_start, xrds_xml_end);
 615                 XML_SetCharacterDataHandler(xp, xrds_xml_chardata);
 616                 XML_Parse(xp, ChrPtr(ReplyBuf), StrLength(ReplyBuf), 0);
 617                 XML_Parse(xp, "", 0, 1);
 618                 XML_ParserFree(xp);
 619         }
 620         else {
 621                 syslog(LOG_ALERT, "Cannot create XML parser");
 622         }
 623
 624         if (xrds.selected_service_priority < INT_MAX) {
 625                 if (oiddata->op_url == NULL) {
 626                         oiddata->op_url = NewStrBuf();
 627                 }
 628                 FlushStrBuf(oiddata->op_url);
 629                 StrBufAppendBuf(oiddata->op_url, xrds.selected_service_uri, 0);
 630                 return_value = openid_disco_xrds;
 631         }
 632
 633         FreeStrBuf(&xrds.CharData);
 634         FreeStrBuf(&xrds.current_service_uri);
 635         FreeStrBuf(&xrds.selected_service_uri);
 636
 637         return(return_value);
 638 }
 639
 640
 641 /*
 642  * Callback function for perform_openid2_discovery()
 643  * We're interested in the X-XRDS-Location: header.
 644  */
 645 size_t yadis_headerfunction(void *ptr, size_t size, size_t nmemb, void *userdata) {
 646         char hdr[1024];
 647         StrBuf **x_xrds_location = (StrBuf **) userdata;
 648
 649         memcpy(hdr, ptr, (size*nmemb));
 650         hdr[size*nmemb] = 0;
 651
 652         if (!strncasecmp(hdr, "X-XRDS-Location:", 16)) {
 653                 *x_xrds_location = NewStrBufPlain(&hdr[16], ((size*nmemb)-16));
 654                 StrBufTrim(*x_xrds_location);
 655         }
 656
 657         return(size * nmemb);
 658 }
 659
 660
 661 /* Attempt to perform Yadis discovery as specified in Yadis 1.0 section 6.2.5.
 662  *
 663  * If Yadis fails, we then attempt HTML discovery using the same document.
 664  *
 665  * If successful, returns nonzero and calls parse_xrds_document() to act upon the received data.
 666  * If fails, returns 0 and does nothing else.
 667  */
 668 int perform_openid2_discovery(StrBuf *SuppliedURL) {
 669         ctdl_openid *oiddata = (ctdl_openid *) CC->openid_data;
 670         int docbytes = (-1);
 671         StrBuf *ReplyBuf = NULL;
 672         int return_value = 0;
 673         CURL *curl;
 674         CURLcode result;
 675         char errmsg[1024] = "";
 676         struct curl_slist *my_headers = NULL;
 677         StrBuf *x_xrds_location = NULL;
 678
 679         if (!SuppliedURL) return(0);
 680         syslog(LOG_DEBUG, "perform_openid2_discovery(%s)", ChrPtr(SuppliedURL));
 681         if (StrLength(SuppliedURL) == 0) return(0);
 682
 683         ReplyBuf = NewStrBuf();
 684         if (!ReplyBuf) return(0);
 685
 686         curl = ctdl_openid_curl_easy_init(errmsg);
 687         if (!curl) return(0);
 688
 689         curl_easy_setopt(curl, CURLOPT_URL, ChrPtr(SuppliedURL));
 690         curl_easy_setopt(curl, CURLOPT_WRITEDATA, ReplyBuf);
 691         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, CurlFillStrBuf_callback);
 692
 693         my_headers = curl_slist_append(my_headers, "Accept:");  /* disable the default Accept: header */
 694         my_headers = curl_slist_append(my_headers, "Accept: application/xrds+xml");
 695         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, my_headers);
 696
 697         curl_easy_setopt(curl, CURLOPT_WRITEHEADER, &x_xrds_location);
 698         curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, yadis_headerfunction);
 699
 700         result = curl_easy_perform(curl);
 701         if (result) {
 702                 syslog(LOG_DEBUG, "libcurl error %d: %s", result, errmsg);
 703         }
 704         curl_slist_free_all(my_headers);
 705         curl_easy_cleanup(curl);
 706         docbytes = StrLength(ReplyBuf);
 707
 708         /*
 709          * The response from the server will be one of:
 710          *
 711          * Option 1: An HTML document with a <head> element that includes a <meta> element with http-equiv
 712          * attribute, X-XRDS-Location,
 713          *
 714          * Does any provider actually do this?  If so then we will implement it in the future.
 715          */
 716
 717         /*
 718          * Option 2: HTTP response-headers that include an X-XRDS-Location response-header,
 719          *           together with a document.
 720          * Option 3: HTTP response-headers only, which MAY include an X-XRDS-Location response-header,
 721          *           a contenttype response-header specifying MIME media type,
 722          *           application/xrds+xml, or both.
 723          *
 724          * If the X-XRDS-Location header was delivered, we know about it at this point...
 725          */
 726         if (    (x_xrds_location)
 727                 && (strcmp(ChrPtr(x_xrds_location), ChrPtr(SuppliedURL)))
 728         ) {
 729                 syslog(LOG_DEBUG, "X-XRDS-Location: %s ... recursing!", ChrPtr(x_xrds_location));
 730                 return_value = perform_openid2_discovery(x_xrds_location);
 731                 FreeStrBuf(&x_xrds_location);
 732         }
 733
 734         /*
 735          * Option 4: the returned web page may *be* an XRDS document.  Try to parse it.
 736          */
 737         if ( (return_value == 0) && (docbytes >= 0)) {
 738                 return_value = parse_xrds_document(ReplyBuf);
 739         }
 740
 741         /*
 742          * Option 5: if all else fails, attempt HTML based discovery.
 743          */
 744         if ( (return_value == 0) && (docbytes >= 0)) {
 745                 if (oiddata->op_url == NULL) {
 746                         oiddata->op_url = NewStrBuf();
 747                 }
 748                 extract_link(oiddata->op_url, HKEY("openid2.provider"), ReplyBuf);
 749                 if (StrLength(oiddata->op_url) > 0) {
 750                         return_value = openid_disco_html;
 751                 }
 752         }
 753
 754         if (ReplyBuf != NULL) {
 755                 FreeStrBuf(&ReplyBuf);
 756         }
 757         return(return_value);
 758 }
 759
 760
 761 /*
 762  * Setup an OpenID authentication
 763  */
 764 void cmd_oids(char *argbuf) {
 765         struct CitContext *CCC = CC;    /* CachedCitContext - performance boost */
 766         const char *Pos = NULL;
 767         StrBuf *ArgBuf = NULL;
 768         StrBuf *ReplyBuf = NULL;
 769         StrBuf *return_to = NULL;
 770         StrBuf *RedirectUrl = NULL;
 771         ctdl_openid *oiddata;
 772         int discovery_succeeded = 0;
 773
 774         Free_ctdl_openid ((ctdl_openid**)&CCC->openid_data);
 775
 776         CCC->openid_data = oiddata = malloc(sizeof(ctdl_openid));
 777         if (oiddata == NULL) {
 778                 syslog(LOG_ALERT, "malloc() failed: %s", strerror(errno));
 779                 cprintf("%d malloc failed\n", ERROR + INTERNAL_ERROR);
 780                 return;
 781         }
 782         memset(oiddata, 0, sizeof(ctdl_openid));
 783         CCC->openid_data = (void *) oiddata;
 784
 785         ArgBuf = NewStrBufPlain(argbuf, -1);
 786
 787         oiddata->verified = 0;
 788         oiddata->claimed_id = NewStrBufPlain(NULL, StrLength(ArgBuf));
 789         return_to = NewStrBufPlain(NULL, StrLength(ArgBuf));
 790
 791         StrBufExtract_NextToken(oiddata->claimed_id, ArgBuf, &Pos, '|');
 792         StrBufExtract_NextToken(return_to, ArgBuf, &Pos, '|');
 793
 794         syslog(LOG_DEBUG, "User-Supplied Identifier is: %s", ChrPtr(oiddata->claimed_id));
 795
 796         /********** OpenID 2.0 section 7.3 - Discovery **********/
 797
 798         /* Section 7.3.1 says we have to attempt XRI based discovery.
 799          * No one is using this, no one is asking for it, no one wants it.
 800          * So we're not even going to bother attempting this mode.
 801          */
 802
 803         /* Attempt section 7.3.2 (Yadis discovery) and section 7.3.3 (HTML discovery);
 804          */
 805         discovery_succeeded = perform_openid2_discovery(oiddata->claimed_id);
 806
 807         if (discovery_succeeded == 0) {
 808                 cprintf("%d There is no OpenID identity provider at this location.\n", ERROR);
 809         }
 810
 811         else {
 812                 /*
 813                  * If we get to this point we are in possession of a valid OpenID Provider URL.
 814                  */
 815                 syslog(LOG_DEBUG, "OP URI '%s' discovered using method %d",
 816                         ChrPtr(oiddata->op_url),
 817                         discovery_succeeded
 818                 );
 819
 820                 /* We have to "normalize" our Claimed ID otherwise it will cause some OP's to barf */
 821                 if (cbmstrcasestr(ChrPtr(oiddata->claimed_id), "://") == NULL) {
 822                         StrBuf *cid = oiddata->claimed_id;
 823                         oiddata->claimed_id = NewStrBufPlain(HKEY("http://"));
 824                         StrBufAppendBuf(oiddata->claimed_id, cid, 0);
 825                         FreeStrBuf(&cid);
 826                 }
 827
 828                 /*
 829                  * OpenID 2.0 section 9: request authentication
 830                  * Assemble a URL to which the user-agent will be redirected.
 831                  */
 832
 833                 RedirectUrl = NewStrBufDup(oiddata->op_url);
 834
 835                 StrBufAppendBufPlain(RedirectUrl, HKEY("?openid.ns="), 0);
 836                 StrBufUrlescAppend(RedirectUrl, NULL, "http://specs.openid.net/auth/2.0");
 837
 838                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.mode=checkid_setup"), 0);
 839
 840                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.claimed_id="), 0);
 841                 StrBufUrlescAppend(RedirectUrl, oiddata->claimed_id, NULL);
 842
 843                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.identity="), 0);
 844                 StrBufUrlescAppend(RedirectUrl, oiddata->claimed_id, NULL);
 845
 846                 /* return_to tells the provider how to complete the round trip back to our site */
 847                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.return_to="), 0);
 848                 StrBufUrlescAppend(RedirectUrl, return_to, NULL);
 849
 850                 /* Attribute Exchange
 851                  * See:
 852                  *      http://openid.net/specs/openid-attribute-exchange-1_0.html
 853                  *      http://code.google.com/apis/accounts/docs/OpenID.html#endpoint
 854                  *      http://test-id.net/OP/AXFetch.aspx
 855                  */
 856
 857                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.ns.ax="), 0);
 858                 StrBufUrlescAppend(RedirectUrl, NULL, "http://openid.net/srv/ax/1.0");
 859
 860                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.ax.mode=fetch_request"), 0);
 861
 862                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.ax.required=firstname,lastname,friendly,nickname"), 0);
 863
 864                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.ax.type.firstname="), 0);
 865                 StrBufUrlescAppend(RedirectUrl, NULL, "http://axschema.org/namePerson/first");
 866
 867                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.ax.type.lastname="), 0);
 868                 StrBufUrlescAppend(RedirectUrl, NULL, "http://axschema.org/namePerson/last");
 869
 870                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.ax.type.friendly="), 0);
 871                 StrBufUrlescAppend(RedirectUrl, NULL, "http://axschema.org/namePerson/friendly");
 872
 873                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.ax.type.nickname="), 0);
 874                 StrBufUrlescAppend(RedirectUrl, NULL, "http://axschema.org/namePerson/nickname");
 875
 876                 syslog(LOG_DEBUG, "OpenID: redirecting client to %s", ChrPtr(RedirectUrl));
 877                 cprintf("%d %s\n", CIT_OK, ChrPtr(RedirectUrl));
 878         }
 879
 880         FreeStrBuf(&ArgBuf);
 881         FreeStrBuf(&ReplyBuf);
 882         FreeStrBuf(&return_to);
 883         FreeStrBuf(&RedirectUrl);
 884 }
 885
 886
 887 /*
 888  * Finalize an OpenID authentication
 889  */
 890 void cmd_oidf(char *argbuf) {
 891         long len;
 892         char buf[2048];
 893         char thiskey[1024];
 894         char thisdata[1024];
 895         HashList *keys = NULL;
 896         const char *Key;
 897         void *Value;
 898         ctdl_openid *oiddata = (ctdl_openid *) CC->openid_data;
 899
 900         if (oiddata == NULL) {
 901                 cprintf("%d run OIDS first.\n", ERROR + INTERNAL_ERROR);
 902                 return;
 903         }
 904         if (StrLength(oiddata->op_url) == 0){
 905                 cprintf("%d No OpenID Endpoint URL has been obtained.\n", ERROR + ILLEGAL_VALUE);
 906                 return;
 907         }
 908         keys = NewHash(1, NULL);
 909         if (!keys) {
 910                 cprintf("%d NewHash() failed\n", ERROR + INTERNAL_ERROR);
 911                 return;
 912         }
 913         cprintf("%d Transmit OpenID data now\n", START_CHAT_MODE);
 914
 915         while (client_getln(buf, sizeof buf), strcmp(buf, "000")) {
 916                 len = extract_token(thiskey, buf, 0, '|', sizeof thiskey);
 917                 if (len < 0) {
 918                         len = sizeof(thiskey) - 1;
 919                 }
 920                 extract_token(thisdata, buf, 1, '|', sizeof thisdata);
 921                 Put(keys, thiskey, len, strdup(thisdata), NULL);
 922         }
 923
 924         /* Check to see if this is a correct response.
 925          * Start with verified=1 but then set it to 0 if anything looks wrong.
 926          */
 927         oiddata->verified = 1;
 928
 929         char *openid_ns = NULL;
 930         if (    (!GetHash(keys, "ns", 2, (void *) &openid_ns))
 931                 || (strcasecmp(openid_ns, "http://specs.openid.net/auth/2.0"))
 932         ) {
 933                 syslog(LOG_DEBUG, "This is not an an OpenID assertion");
 934                 oiddata->verified = 0;
 935         }
 936
 937         char *openid_mode = NULL;
 938         if (    (!GetHash(keys, "mode", 4, (void *) &openid_mode))
 939                 || (strcasecmp(openid_mode, "id_res"))
 940         ) {
 941                 oiddata->verified = 0;
 942         }
 943
 944         char *openid_claimed_id = NULL;
 945         if (GetHash(keys, "claimed_id", 10, (void *) &openid_claimed_id)) {
 946                 FreeStrBuf(&oiddata->claimed_id);
 947                 oiddata->claimed_id = NewStrBufPlain(openid_claimed_id, -1);
 948                 syslog(LOG_DEBUG, "Provider is asserting the Claimed ID '%s'", ChrPtr(oiddata->claimed_id));
 949         }
 950
 951         /* Validate the assertion against the server */
 952         syslog(LOG_DEBUG, "Validating...");
 953
 954         CURL *curl;
 955         CURLcode res;
 956         struct curl_httppost *formpost = NULL;
 957         struct curl_httppost *lastptr = NULL;
 958         char errmsg[1024] = "";
 959         StrBuf *ReplyBuf = NewStrBuf();
 960
 961         curl_formadd(&formpost, &lastptr,
 962                 CURLFORM_COPYNAME,      "openid.mode",
 963                 CURLFORM_COPYCONTENTS,  "check_authentication",
 964                 CURLFORM_END
 965         );
 966
 967         HashPos *HashPos = GetNewHashPos(keys, 0);
 968         while (GetNextHashPos(keys, HashPos, &len, &Key, &Value) != 0) {
 969                 syslog(LOG_DEBUG, "%s = %s", Key, (char *)Value);
 970                 if (strcasecmp(Key, "mode")) {
 971                         char k_o_keyname[1024];
 972                         snprintf(k_o_keyname, sizeof k_o_keyname, "openid.%s", (const char *)Key);
 973                         curl_formadd(&formpost, &lastptr,
 974                                 CURLFORM_COPYNAME,      k_o_keyname,
 975                                 CURLFORM_COPYCONTENTS,  (char *)Value,
 976                                 CURLFORM_END
 977                         );
 978                 }
 979         }
 980
 981         curl = ctdl_openid_curl_easy_init(errmsg);
 982         curl_easy_setopt(curl, CURLOPT_URL, ChrPtr(oiddata->op_url));
 983         curl_easy_setopt(curl, CURLOPT_WRITEDATA, ReplyBuf);
 984         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, CurlFillStrBuf_callback);
 985         curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost);
 986
 987         res = curl_easy_perform(curl);
 988         if (res) {
 989                 syslog(LOG_DEBUG, "cmd_oidf() libcurl error %d: %s", res, errmsg);
 990                 oiddata->verified = 0;
 991         }
 992         curl_easy_cleanup(curl);
 993         curl_formfree(formpost);
 994
 995         /* syslog(LOG_DEBUG, "Validation reply: \n%s", ChrPtr(ReplyBuf)); */
 996         if (cbmstrcasestr(ChrPtr(ReplyBuf), "is_valid:true") == NULL) {
 997                 oiddata->verified = 0;
 998         }
 999         FreeStrBuf(&ReplyBuf);
1000
1001         syslog(LOG_DEBUG, "OpenID authentication %s", (oiddata->verified ? "succeeded" : "failed") );
1002
1003         /* Respond to the client */
1004
1005         if (oiddata->verified) {
1006
1007                 /* If we were already logged in, attach the OpenID to the user's account */
1008                 if (CC->logged_in) {
1009                         if (attach_openid(&CC->user, oiddata->claimed_id) == 0) {
1010                                 cprintf("attach\n");
1011                                 syslog(LOG_DEBUG, "OpenID attach succeeded");
1012                         }
1013                         else {
1014                                 cprintf("fail\n");
1015                                 syslog(LOG_DEBUG, "OpenID attach failed");
1016                         }
1017                 }
1018
1019                 /* Otherwise, a user is attempting to log in using the verified OpenID */
1020                 else {
1021                         /*
1022                          * Existing user who has claimed this OpenID?
1023                          *
1024                          * Note: if you think that sending the password back over the wire is insecure,
1025                          * check your assumptions.  If someone has successfully asserted an OpenID that
1026                          * is associated with the account, they already have password equivalency and can
1027                          * login, so they could just as easily change the password, etc.
1028                          */
1029                         if (login_via_openid(oiddata->claimed_id) == 0) {
1030                                 cprintf("authenticate\n%s\n%s\n", CC->user.fullname, CC->user.password);
1031                                 logged_in_response();
1032                                 syslog(LOG_DEBUG, "Logged in using previously claimed OpenID");
1033                         }
1034
1035                         /*
1036                          * If this system does not allow self-service new user registration, the
1037                          * remaining modes do not apply, so fail here and now.
1038                          */
1039                         else if (config.c_disable_newu) {
1040                                 cprintf("fail\n");
1041                                 syslog(LOG_DEBUG, "Creating user failed due to local policy");
1042                         }
1043
1044                         /*
1045                          * New user whose OpenID is verified and Attribute Exchange gave us a name?
1046                          */
1047                         else if (openid_create_user_via_ax(oiddata->claimed_id, keys) == 0) {
1048                                 cprintf("authenticate\n%s\n%s\n", CC->user.fullname, CC->user.password);
1049                                 logged_in_response();
1050                                 syslog(LOG_DEBUG, "Successfully auto-created new user");
1051                         }
1052
1053                         /*
1054                          * OpenID is verified, but the desired username either was not specified or
1055                          * conflicts with an existing user.  Manual account creation is required.
1056                          */
1057                         else {
1058                                 char *desired_name = NULL;
1059                                 cprintf("verify_only\n");
1060                                 cprintf("%s\n", ChrPtr(oiddata->claimed_id));
1061                                 if (GetHash(keys, "sreg.nickname", 13, (void *) &desired_name)) {
1062                                         cprintf("%s\n", desired_name);
1063                                 }
1064                                 else {
1065                                         cprintf("\n");
1066                                 }
1067                                 syslog(LOG_DEBUG, "The desired display name is already taken.");
1068                         }
1069                 }
1070         }
1071         else {
1072                 cprintf("fail\n");
1073         }
1074         cprintf("000\n");
1075
1076         if (oiddata->sreg_keys != NULL) {
1077                 DeleteHash(&oiddata->sreg_keys);
1078                 oiddata->sreg_keys = NULL;
1079         }
1080         oiddata->sreg_keys = keys;
1081 }
1082
1083
1084
1085 /**************************************************************************/
1086 /*                                                                        */
1087 /* Functions in this section handle module initialization and shutdown    */
1088 /*                                                                        */
1089 /**************************************************************************/
1090
1091
1092
1093
1094 CTDL_MODULE_INIT(openid_rp)
1095 {
1096         if (!threading) {
1097                 curl_global_init(CURL_GLOBAL_ALL);
1098
1099                 /* Only enable the OpenID command set when native mode authentication is in use. */
1100                 if (config.c_auth_mode == AUTHMODE_NATIVE) {
1101                         CtdlRegisterProtoHook(cmd_oids, "OIDS", "Setup OpenID authentication");
1102                         CtdlRegisterProtoHook(cmd_oidf, "OIDF", "Finalize OpenID authentication");
1103                         CtdlRegisterProtoHook(cmd_oidl, "OIDL", "List OpenIDs associated with an account");
1104                         CtdlRegisterProtoHook(cmd_oidd, "OIDD", "Detach an OpenID from an account");
1105                         CtdlRegisterProtoHook(cmd_oidc, "OIDC", "Create new user after validating OpenID");
1106                         CtdlRegisterProtoHook(cmd_oida, "OIDA", "List all OpenIDs in the database");
1107                 }
1108                 CtdlRegisterSessionHook(openid_cleanup_function, EVT_LOGOUT);
1109                 CtdlRegisterUserHook(openid_purge, EVT_PURGEUSER);
1110                 openid_level_supported = 1;     /* This module supports OpenID 1.0 only */
1111         }
1112
1113         /* return our module name for the log */
1114         return "openid_rp";
1115 }