citadel/server/modules/openid/serv_openid_rp.c

   1 // This is an implementation of OpenID 2.0 relying party support in stateless mode.
   2 //
   3 // Copyright (c) 2007-2022 by the citadel.org team
   4 //
   5 // This program is open source software.  Use, duplication, or disclosure
   6 // is subject to the terms of the GNU General Public License, version 3.
   7
   8 #include "../../sysdep.h"
   9 #include <stdlib.h>
  10 #include <unistd.h>
  11 #include <stdio.h>
  12 #include <fcntl.h>
  13 #include <signal.h>
  14 #include <pwd.h>
  15 #include <errno.h>
  16 #include <sys/types.h>
  17 #include <time.h>
  18 #include <sys/wait.h>
  19 #include <string.h>
  20 #include <limits.h>
  21 #include <curl/curl.h>
  22 #include <expat.h>
  23 #include "../../ctdl_module.h"
  24 #include "../../config.h"
  25 #include "../../citserver.h"
  26 #include "../../user_ops.h"
  27
  28 typedef struct _ctdl_openid {
  29         StrBuf *op_url;                 // OpenID Provider Endpoint URL
  30         StrBuf *claimed_id;             // Claimed Identifier
  31         int verified;
  32         HashList *sreg_keys;
  33 } ctdl_openid;
  34
  35 enum {
  36         openid_disco_none,
  37         openid_disco_xrds,
  38         openid_disco_html
  39 };
  40
  41
  42 void Free_ctdl_openid(ctdl_openid **FreeMe) {
  43         if (*FreeMe == NULL) {
  44                 return;
  45         }
  46         FreeStrBuf(&(*FreeMe)->op_url);
  47         FreeStrBuf(&(*FreeMe)->claimed_id);
  48         DeleteHash(&(*FreeMe)->sreg_keys);
  49         free(*FreeMe);
  50         *FreeMe = NULL;
  51 }
  52
  53
  54 // This cleanup function blows away the temporary memory used by this module.
  55 void openid_cleanup_function(void) {
  56
  57         if (CC->openid_data != NULL) {
  58                 syslog(LOG_DEBUG, "openid: Clearing OpenID session state");
  59                 Free_ctdl_openid((ctdl_openid **) &CC->openid_data);
  60         }
  61 }
  62
  63
  64 // Functions in this section handle Citadel internal OpenID mapping stuff
  65
  66
  67 // The structure of an openid record *key* is:
  68 //
  69 // |--------------claimed_id-------------|
  70 //     (actual length of claimed id)
  71 //
  72 //
  73 // The structure of an openid record *value* is:
  74 //
  75 // |-----user_number----|------------claimed_id---------------|
  76 //    (sizeof long)          (actual length of claimed id)
  77
  78
  79
  80 // Attach an external authenticator (such as an OpenID) to a Citadel account
  81 int attach_extauth(struct ctdluser *who, StrBuf *claimed_id) {
  82         struct cdbdata *cdboi;
  83         long fetched_usernum;
  84         char *data;
  85         int data_len;
  86         char buf[2048];
  87
  88         if (!who) return(1);
  89         if (StrLength(claimed_id)==0) return(1);
  90
  91         // Check to see if this authenticator is already in the database
  92
  93         cdboi = cdb_fetch(CDB_EXTAUTH, ChrPtr(claimed_id), StrLength(claimed_id));
  94         if (cdboi != NULL) {
  95                 memcpy(&fetched_usernum, cdboi->ptr, sizeof(long));
  96                 cdb_free(cdboi);
  97
  98                 if (fetched_usernum == who->usernum) {
  99                         syslog(LOG_INFO, "openid: %s already associated; no action is taken", ChrPtr(claimed_id));
 100                         return(0);
 101                 }
 102                 else {
 103                         syslog(LOG_INFO, "openid: %s already belongs to another user", ChrPtr(claimed_id));
 104                         return(3);
 105                 }
 106         }
 107
 108         // Not already in the database, so attach it now
 109
 110         data_len = sizeof(long) + StrLength(claimed_id) + 1;
 111         data = malloc(data_len);
 112
 113         memcpy(data, &who->usernum, sizeof(long));
 114         memcpy(&data[sizeof(long)], ChrPtr(claimed_id), StrLength(claimed_id) + 1);
 115
 116         cdb_store(CDB_EXTAUTH, ChrPtr(claimed_id), StrLength(claimed_id), data, data_len);
 117         free(data);
 118
 119         snprintf(buf, sizeof buf, "User <%s> (#%ld) is now associated with %s\n", who->fullname, who->usernum, ChrPtr(claimed_id));
 120         CtdlAideMessage(buf, "External authenticator claim");
 121         syslog(LOG_INFO, "openid: %s", buf);
 122         return(0);
 123 }
 124
 125
 126 // When a user is being deleted, we have to delete any OpenID associations
 127 void extauth_purge(struct ctdluser *usbuf) {
 128         struct cdbdata *cdboi;
 129         HashList *keys = NULL;
 130         HashPos *HashPos;
 131         char *deleteme = NULL;
 132         long len;
 133         void *Value;
 134         const char *Key;
 135         long usernum = 0L;
 136
 137         keys = NewHash(1, NULL);
 138         if (!keys) return;
 139
 140         cdb_rewind(CDB_EXTAUTH);
 141         while (cdboi = cdb_next_item(CDB_EXTAUTH), cdboi != NULL) {
 142                 if (cdboi->len > sizeof(long)) {
 143                         memcpy(&usernum, cdboi->ptr, sizeof(long));
 144                         if (usernum == usbuf->usernum) {
 145                                 deleteme = strdup(cdboi->ptr + sizeof(long)),
 146                                 Put(keys, deleteme, strlen(deleteme), deleteme, NULL);
 147                         }
 148                 }
 149                 cdb_free(cdboi);
 150         }
 151
 152         // Go through the hash list, deleting keys we stored in it
 153
 154         HashPos = GetNewHashPos(keys, 0);
 155         while (GetNextHashPos(keys, HashPos, &len, &Key, &Value)!=0)
 156         {
 157                 syslog(LOG_DEBUG, "openid: deleting associated external authenticator <%s>", (char*)Value);
 158                 cdb_delete(CDB_EXTAUTH, Value, strlen(Value));
 159                 // note: don't free(Value) -- deleting the hash list will handle this for us
 160         }
 161         DeleteHashPos(&HashPos);
 162         DeleteHash(&keys);
 163 }
 164
 165
 166 // List the OpenIDs associated with the currently logged in account
 167 void cmd_oidl(char *argbuf) {
 168         struct cdbdata *cdboi;
 169         long usernum = 0L;
 170
 171         if (CtdlGetConfigInt("c_disable_newu")) {
 172                 cprintf("%d this system does not support openid.\n", ERROR + CMD_NOT_SUPPORTED);
 173                 return;
 174         }
 175         if (CtdlAccessCheck(ac_logged_in)) return;
 176
 177         cdb_rewind(CDB_EXTAUTH);
 178         cprintf("%d Associated external authenticators:\n", LISTING_FOLLOWS);
 179
 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 == CC->user.usernum) {
 184                                 cprintf("%s\n", cdboi->ptr + sizeof(long));
 185                         }
 186                 }
 187                 cdb_free(cdboi);
 188         }
 189         cprintf("000\n");
 190 }
 191
 192
 193 // List ALL OpenIDs in the database
 194 void cmd_oida(char *argbuf) {
 195         struct cdbdata *cdboi;
 196         long usernum;
 197         struct ctdluser usbuf;
 198
 199         if (CtdlGetConfigInt("c_disable_newu")) {
 200                 cprintf("%d this system does not support openid.\n",
 201                         ERROR + CMD_NOT_SUPPORTED);
 202                 return;
 203         }
 204         if (CtdlAccessCheck(ac_aide)) return;
 205         cdb_rewind(CDB_EXTAUTH);
 206         cprintf("%d List of all OpenIDs in the database:\n", LISTING_FOLLOWS);
 207
 208         while (cdboi = cdb_next_item(CDB_EXTAUTH), cdboi != NULL) {
 209                 if (cdboi->len > sizeof(long)) {
 210                         memcpy(&usernum, cdboi->ptr, sizeof(long));
 211                         if (CtdlGetUserByNumber(&usbuf, usernum) != 0) {
 212                                 usbuf.fullname[0] = 0;
 213                         }
 214                         cprintf("%s|%ld|%s\n",
 215                                 cdboi->ptr + sizeof(long),
 216                                 usernum,
 217                                 usbuf.fullname
 218                         );
 219                 }
 220                 cdb_free(cdboi);
 221         }
 222         cprintf("000\n");
 223 }
 224
 225
 226 // Create a new user account, manually specifying the name, after successfully
 227 // verifying an OpenID (which will of course be attached to the account)
 228 void cmd_oidc(char *argbuf) {
 229         ctdl_openid *oiddata = (ctdl_openid *) CC->openid_data;
 230
 231         if (CtdlGetConfigInt("c_disable_newu")) {
 232                 cprintf("%d this system does not support openid.\n",
 233                         ERROR + CMD_NOT_SUPPORTED);
 234                 return;
 235         }
 236         if ( (!oiddata) || (!oiddata->verified) ) {
 237                 cprintf("%d You have not verified an OpenID yet.\n", ERROR);
 238                 return;
 239         }
 240
 241         // We can make the semantics of OIDC exactly the same as NEWU, simply
 242         // by _calling_ cmd_newu() and letting it run.  Very clever!
 243         cmd_newu(argbuf);
 244
 245         // Now, if this logged us in, we have to attach the OpenID
 246         if (CC->logged_in) {
 247                 attach_extauth(&CC->user, oiddata->claimed_id);
 248         }
 249
 250 }
 251
 252
 253 // Detach an OpenID from the currently logged in account
 254 void cmd_oidd(char *argbuf) {
 255         struct cdbdata *cdboi;
 256         char id_to_detach[1024];
 257         int this_is_mine = 0;
 258         long usernum = 0L;
 259
 260         if (CtdlGetConfigInt("c_disable_newu")) {
 261                 cprintf("%d this system does not support openid.\n",
 262                         ERROR + CMD_NOT_SUPPORTED);
 263                 return;
 264         }
 265         if (CtdlAccessCheck(ac_logged_in)) return;
 266         extract_token(id_to_detach, argbuf, 0, '|', sizeof id_to_detach);
 267         if (IsEmptyStr(id_to_detach)) {
 268                 cprintf("%d An empty OpenID URL is not allowed.\n", ERROR + ILLEGAL_VALUE);
 269         }
 270
 271         cdb_rewind(CDB_EXTAUTH);
 272         while (cdboi = cdb_next_item(CDB_EXTAUTH), cdboi != NULL) {
 273                 if (cdboi->len > sizeof(long)) {
 274                         memcpy(&usernum, cdboi->ptr, sizeof(long));
 275                         if (usernum == CC->user.usernum) {
 276                                 this_is_mine = 1;
 277                         }
 278                 }
 279                 cdb_free(cdboi);
 280         }
 281
 282         if (!this_is_mine) {
 283                 cprintf("%d That OpenID was not found or not associated with your account.\n",
 284                         ERROR + ILLEGAL_VALUE);
 285                 return;
 286         }
 287
 288         cdb_delete(CDB_EXTAUTH, id_to_detach, strlen(id_to_detach));
 289         cprintf("%d %s detached from your account.\n", CIT_OK, id_to_detach);
 290 }
 291
 292
 293 // Attempt to auto-create a new Citadel account using the nickname from Attribute Exchange
 294 int openid_create_user_via_ax(StrBuf *claimed_id, HashList *sreg_keys) {
 295         char *nickname = NULL;
 296         char *firstname = NULL;
 297         char *lastname = NULL;
 298         char new_password[32];
 299         long len;
 300         const char *Key;
 301         void *Value;
 302
 303         if (CtdlGetConfigInt("c_auth_mode") != AUTHMODE_NATIVE) return(1);
 304         if (CtdlGetConfigInt("c_disable_newu")) return(2);
 305         if (CC->logged_in) return(3);
 306
 307         HashPos *HashPos = GetNewHashPos(sreg_keys, 0);
 308         while (GetNextHashPos(sreg_keys, HashPos, &len, &Key, &Value) != 0) {
 309                 syslog(LOG_DEBUG, "openid: %s = %s", Key, (char *)Value);
 310
 311                 if (cbmstrcasestr(Key, "value.nickname") != NULL) {
 312                         nickname = (char *)Value;
 313                 }
 314                 else if ( (nickname == NULL) && (cbmstrcasestr(Key, "value.nickname") != NULL)) {
 315                         nickname = (char *)Value;
 316                 }
 317                 else if (cbmstrcasestr(Key, "value.firstname") != NULL) {
 318                         firstname = (char *)Value;
 319                 }
 320                 else if (cbmstrcasestr(Key, "value.lastname") != NULL) {
 321                         lastname = (char *)Value;
 322                 }
 323
 324         }
 325         DeleteHashPos(&HashPos);
 326
 327         if (nickname == NULL) {
 328                 if ((firstname != NULL) || (lastname != NULL)) {
 329                         char fullname[1024] = "";
 330                         if (firstname) strcpy(fullname, firstname);
 331                         if (firstname && lastname) strcat(fullname, " ");
 332                         if (lastname) strcat(fullname, lastname);
 333                         nickname = fullname;
 334                 }
 335         }
 336
 337         if (nickname == NULL) {
 338                 return(4);
 339         }
 340         syslog(LOG_DEBUG, "openid: the desired account name is <%s>", nickname);
 341
 342         if (!CtdlGetUser(&CC->user, nickname)) {
 343                 syslog(LOG_DEBUG, "openid: <%s> is already taken by another user.", nickname);
 344                 memset(&CC->user, 0, sizeof(struct ctdluser));
 345                 return(5);
 346         }
 347
 348         // The desired account name is available.  Create the account and log it in!
 349         if (create_user(nickname, CREATE_USER_BECOME_USER, NATIVE_AUTH_UID)) return(6);
 350
 351         // Generate a random password.
 352         // The user doesn't care what the password is since he is using OpenID.
 353         snprintf(new_password, sizeof new_password, "%08lx%08lx", random(), random());
 354         CtdlSetPassword(new_password);
 355
 356         // Now attach the verified OpenID to this account.
 357         attach_extauth(&CC->user, claimed_id);
 358
 359         return(0);
 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 int login_via_extauth(StrBuf *claimed_id) {
 366         struct cdbdata *cdboi;
 367         long usernum = 0;
 368
 369         cdboi = cdb_fetch(CDB_EXTAUTH, ChrPtr(claimed_id), StrLength(claimed_id));
 370         if (cdboi == NULL) {
 371                 return(-1);
 372         }
 373
 374         memcpy(&usernum, cdboi->ptr, sizeof(long));
 375         cdb_free(cdboi);
 376
 377         if (!CtdlGetUserByNumber(&CC->user, usernum)) {
 378                 // Now become the user we just created
 379                 safestrncpy(CC->curr_user, CC->user.fullname, sizeof CC->curr_user);
 380                 do_login();
 381                 return(0);
 382         }
 383         else {
 384                 memset(&CC->user, 0, sizeof(struct ctdluser));
 385                 return(-1);
 386         }
 387 }
 388
 389
 390 // Functions in this section handle OpenID protocol
 391
 392
 393 // Locate a <link> tag and, given its 'rel=' parameter, return its 'href' parameter
 394 void extract_link(StrBuf *target_buf, const char *rel, long repllen, StrBuf *source_buf) {
 395         int i;
 396         const char *ptr;
 397         const char *href_start = NULL;
 398         const char *href_end = NULL;
 399         const char *link_tag_start = NULL;
 400         const char *link_tag_end = NULL;
 401         const char *rel_start = NULL;
 402         const char *rel_end = NULL;
 403
 404         if (!target_buf) return;
 405         if (!rel) return;
 406         if (!source_buf) return;
 407
 408         ptr = ChrPtr(source_buf);
 409
 410         FlushStrBuf(target_buf);
 411         while (ptr = cbmstrcasestr(ptr, "<link"), ptr != NULL) {
 412
 413                 link_tag_start = ptr;
 414                 link_tag_end = strchr(ptr, '>');
 415                 if (link_tag_end == NULL)
 416                         break;
 417                 for (i=0; i < 1; i++ ){
 418                         rel_start = cbmstrcasestr(link_tag_start, "rel=");
 419                         if ((rel_start == NULL) ||
 420                             (rel_start > link_tag_end))
 421                                 continue;
 422
 423                         rel_start = strchr(rel_start, '\"');
 424                         if ((rel_start == NULL) ||
 425                             (rel_start > link_tag_end))
 426                                 continue;
 427                         ++rel_start;
 428                         rel_end = strchr(rel_start, '\"');
 429                         if ((rel_end == NULL) ||
 430                             (rel_end == rel_start) ||
 431                             (rel_end >= link_tag_end) )
 432                                 continue;
 433                         if (strncasecmp(rel, rel_start, repllen)!= 0)
 434                                 continue; // didn't match? never mind...
 435
 436                         href_start = cbmstrcasestr(link_tag_start, "href=");
 437                         if ((href_start == NULL) ||
 438                             (href_start >= link_tag_end))
 439                                 continue;
 440                         href_start = strchr(href_start, '\"');
 441                         if ((href_start == NULL) |
 442                             (href_start >= link_tag_end))
 443                                 continue;
 444                         ++href_start;
 445                         href_end = strchr(href_start, '\"');
 446                         if ((href_end == NULL) ||
 447                             (href_end == href_start) ||
 448                             (href_start >= link_tag_end))
 449                                 continue;
 450                         StrBufPlain(target_buf, href_start, href_end - href_start);
 451                 }
 452                 ptr = link_tag_end;
 453         }
 454 }
 455
 456
 457 // Wrapper for curl_easy_init() that includes the options common to all calls used in this module.
 458 CURL *ctdl_openid_curl_easy_init(char *errmsg) {
 459         CURL *curl;
 460
 461         curl = curl_easy_init();
 462         if (!curl) {
 463                 return(curl);
 464         }
 465
 466         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0);
 467         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0);
 468
 469         if (errmsg) {
 470                 curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, errmsg);
 471         }
 472         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
 473 #ifdef CURLOPT_HTTP_CONTENT_DECODING
 474         curl_easy_setopt(curl, CURLOPT_HTTP_CONTENT_DECODING, 1);
 475         curl_easy_setopt(curl, CURLOPT_ENCODING, "");
 476 #endif
 477         curl_easy_setopt(curl, CURLOPT_USERAGENT, CITADEL);
 478         curl_easy_setopt(curl, CURLOPT_TIMEOUT, 30);            // die after 30 seconds
 479
 480         if (
 481                 (!IsEmptyStr(CtdlGetConfigStr("c_ip_addr")))
 482                 && (strcmp(CtdlGetConfigStr("c_ip_addr"), "*"))
 483                 && (strcmp(CtdlGetConfigStr("c_ip_addr"), "::"))
 484                 && (strcmp(CtdlGetConfigStr("c_ip_addr"), "0.0.0.0"))
 485         ) {
 486                 curl_easy_setopt(curl, CURLOPT_INTERFACE, CtdlGetConfigStr("c_ip_addr"));
 487         }
 488
 489         return(curl);
 490 }
 491
 492
 493 struct xrds {
 494         StrBuf *CharData;
 495         int nesting_level;
 496         int in_xrd;
 497         int current_service_priority;
 498         int selected_service_priority;
 499         StrBuf *current_service_uri;
 500         StrBuf *selected_service_uri;
 501         int current_service_is_oid2auth;
 502 };
 503
 504
 505 void xrds_xml_start(void *data, const char *supplied_el, const char **attr) {
 506         struct xrds *xrds = (struct xrds *) data;
 507         int i;
 508
 509         ++xrds->nesting_level;
 510
 511         if (!strcasecmp(supplied_el, "XRD")) {
 512                 ++xrds->in_xrd;
 513         }
 514
 515         else if (!strcasecmp(supplied_el, "service")) {
 516                 xrds->current_service_priority = 0;
 517                 xrds->current_service_is_oid2auth = 0;
 518                 for (i=0; attr[i] != NULL; i+=2) {
 519                         if (!strcasecmp(attr[i], "priority")) {
 520                                 xrds->current_service_priority = atoi(attr[i+1]);
 521                         }
 522                 }
 523         }
 524
 525         FlushStrBuf(xrds->CharData);
 526 }
 527
 528
 529 void xrds_xml_end(void *data, const char *supplied_el) {
 530         struct xrds *xrds = (struct xrds *) data;
 531
 532         --xrds->nesting_level;
 533
 534         if (!strcasecmp(supplied_el, "XRD")) {
 535                 --xrds->in_xrd;
 536         }
 537
 538         else if (!strcasecmp(supplied_el, "type")) {
 539                 if (    (xrds->in_xrd)
 540                         && (!strcasecmp(ChrPtr(xrds->CharData), "http://specs.openid.net/auth/2.0/server"))
 541                 ) {
 542                         xrds->current_service_is_oid2auth = 1;
 543                 }
 544                 if (    (xrds->in_xrd)
 545                         && (!strcasecmp(ChrPtr(xrds->CharData), "http://specs.openid.net/auth/2.0/signon"))
 546                 ) {
 547                         xrds->current_service_is_oid2auth = 1;
 548                         // FIXME in this case, the Claimed ID should be considered immutable
 549                 }
 550         }
 551
 552         else if (!strcasecmp(supplied_el, "uri")) {
 553                 if (xrds->in_xrd) {
 554                         FlushStrBuf(xrds->current_service_uri);
 555                         StrBufAppendBuf(xrds->current_service_uri, xrds->CharData, 0);
 556                 }
 557         }
 558
 559         else if (!strcasecmp(supplied_el, "service")) {
 560                 if (    (xrds->in_xrd)
 561                         && (xrds->current_service_priority < xrds->selected_service_priority)
 562                         && (xrds->current_service_is_oid2auth)
 563                 ) {
 564                         xrds->selected_service_priority = xrds->current_service_priority;
 565                         FlushStrBuf(xrds->selected_service_uri);
 566                         StrBufAppendBuf(xrds->selected_service_uri, xrds->current_service_uri, 0);
 567                 }
 568
 569         }
 570
 571         FlushStrBuf(xrds->CharData);
 572 }
 573
 574
 575 void xrds_xml_chardata(void *data, const XML_Char *s, int len) {
 576         struct xrds *xrds = (struct xrds *) data;
 577
 578         StrBufAppendBufPlain (xrds->CharData, s, len, 0);
 579 }
 580
 581
 582 // Parse an XRDS document.
 583 // If an OpenID Provider URL is discovered, op_url to that value and return nonzero.
 584 // If nothing useful happened, return 0.
 585 int parse_xrds_document(StrBuf *ReplyBuf) {
 586         ctdl_openid *oiddata = (ctdl_openid *) CC->openid_data;
 587         struct xrds xrds;
 588         int return_value = 0;
 589
 590         memset(&xrds, 0, sizeof (struct xrds));
 591         xrds.selected_service_priority = INT_MAX;
 592         xrds.CharData = NewStrBuf();
 593         xrds.current_service_uri = NewStrBuf();
 594         xrds.selected_service_uri = NewStrBuf();
 595         XML_Parser xp = XML_ParserCreate(NULL);
 596         if (xp) {
 597                 XML_SetUserData(xp, &xrds);
 598                 XML_SetElementHandler(xp, xrds_xml_start, xrds_xml_end);
 599                 XML_SetCharacterDataHandler(xp, xrds_xml_chardata);
 600                 XML_Parse(xp, ChrPtr(ReplyBuf), StrLength(ReplyBuf), 0);
 601                 XML_Parse(xp, "", 0, 1);
 602                 XML_ParserFree(xp);
 603         }
 604         else {
 605                 syslog(LOG_ERR, "openid: cannot create XML parser");
 606         }
 607
 608         if (xrds.selected_service_priority < INT_MAX) {
 609                 if (oiddata->op_url == NULL) {
 610                         oiddata->op_url = NewStrBuf();
 611                 }
 612                 FlushStrBuf(oiddata->op_url);
 613                 StrBufAppendBuf(oiddata->op_url, xrds.selected_service_uri, 0);
 614                 return_value = openid_disco_xrds;
 615         }
 616
 617         FreeStrBuf(&xrds.CharData);
 618         FreeStrBuf(&xrds.current_service_uri);
 619         FreeStrBuf(&xrds.selected_service_uri);
 620
 621         return(return_value);
 622 }
 623
 624
 625 // Callback function for perform_openid2_discovery()
 626 // We're interested in the X-XRDS-Location: header.
 627 size_t yadis_headerfunction(void *ptr, size_t size, size_t nmemb, void *userdata) {
 628         char hdr[1024];
 629         StrBuf **x_xrds_location = (StrBuf **) userdata;
 630
 631         memcpy(hdr, ptr, (size*nmemb));
 632         hdr[size*nmemb] = 0;
 633
 634         if (!strncasecmp(hdr, "X-XRDS-Location:", 16)) {
 635                 *x_xrds_location = NewStrBufPlain(&hdr[16], ((size*nmemb)-16));
 636                 StrBufTrim(*x_xrds_location);
 637         }
 638
 639         return(size * nmemb);
 640 }
 641
 642
 643 // Attempt to perform Yadis discovery as specified in Yadis 1.0 section 6.2.5.
 644 //
 645 // If Yadis fails, we then attempt HTML discovery using the same document.
 646 //
 647 // If successful, returns nonzero and calls parse_xrds_document() to act upon the received data.
 648 // If fails, returns 0 and does nothing else.
 649 int perform_openid2_discovery(StrBuf *SuppliedURL) {
 650         ctdl_openid *oiddata = (ctdl_openid *) CC->openid_data;
 651         int docbytes = (-1);
 652         StrBuf *ReplyBuf = NULL;
 653         int return_value = 0;
 654         CURL *curl;
 655         CURLcode result;
 656         char errmsg[1024] = "";
 657         struct curl_slist *my_headers = NULL;
 658         StrBuf *x_xrds_location = NULL;
 659
 660         if (!SuppliedURL) return(0);
 661         syslog(LOG_DEBUG, "openid: perform_openid2_discovery(%s)", ChrPtr(SuppliedURL));
 662         if (StrLength(SuppliedURL) == 0) return(0);
 663
 664         ReplyBuf = NewStrBuf();
 665         if (!ReplyBuf) return(0);
 666
 667         curl = ctdl_openid_curl_easy_init(errmsg);
 668         if (!curl) return(0);
 669
 670         curl_easy_setopt(curl, CURLOPT_URL, ChrPtr(SuppliedURL));
 671         curl_easy_setopt(curl, CURLOPT_WRITEDATA, ReplyBuf);
 672         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, CurlFillStrBuf_callback);
 673
 674         my_headers = curl_slist_append(my_headers, "Accept:");  // disable the default Accept: header
 675         my_headers = curl_slist_append(my_headers, "Accept: application/xrds+xml");
 676         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, my_headers);
 677
 678         curl_easy_setopt(curl, CURLOPT_WRITEHEADER, &x_xrds_location);
 679         curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, yadis_headerfunction);
 680
 681         result = curl_easy_perform(curl);
 682         if (result) {
 683                 syslog(LOG_DEBUG, "openid: libcurl error %d: %s", result, errmsg);
 684         }
 685         curl_slist_free_all(my_headers);
 686         curl_easy_cleanup(curl);
 687         docbytes = StrLength(ReplyBuf);
 688
 689         // The response from the server will be one of:
 690         //
 691         // Option 1: An HTML document with a <head> element that includes a <meta> element with http-equiv
 692         // attribute, X-XRDS-Location,
 693         //
 694         // Does any provider actually do this?  If so then we will implement it in the future.
 695         //
 696         // Option 2: HTTP response-headers that include an X-XRDS-Location response-header,
 697         //           together with a document.
 698         // Option 3: HTTP response-headers only, which MAY include an X-XRDS-Location response-header,
 699         //           a contenttype response-header specifying MIME media type,
 700         //           application/xrds+xml, or both.
 701         //
 702         // If the X-XRDS-Location header was delivered, we know about it at this point...
 703         if (    (x_xrds_location)
 704                 && (strcmp(ChrPtr(x_xrds_location), ChrPtr(SuppliedURL)))
 705         ) {
 706                 syslog(LOG_DEBUG, "openid: X-XRDS-Location: %s ... recursing!", ChrPtr(x_xrds_location));
 707                 return_value = perform_openid2_discovery(x_xrds_location);
 708                 FreeStrBuf(&x_xrds_location);
 709         }
 710
 711         // Option 4: the returned web page may *be* an XRDS document.  Try to parse it.
 712         if ( (return_value == 0) && (docbytes >= 0)) {
 713                 return_value = parse_xrds_document(ReplyBuf);
 714         }
 715
 716         // Option 5: if all else fails, attempt HTML based discovery.
 717         if ( (return_value == 0) && (docbytes >= 0)) {
 718                 if (oiddata->op_url == NULL) {
 719                         oiddata->op_url = NewStrBuf();
 720                 }
 721                 extract_link(oiddata->op_url, HKEY("openid2.provider"), ReplyBuf);
 722                 if (StrLength(oiddata->op_url) > 0) {
 723                         return_value = openid_disco_html;
 724                 }
 725         }
 726
 727         if (ReplyBuf != NULL) {
 728                 FreeStrBuf(&ReplyBuf);
 729         }
 730         return(return_value);
 731 }
 732
 733
 734 // Setup an OpenID authentication
 735 void cmd_oids(char *argbuf) {
 736         const char *Pos = NULL;
 737         StrBuf *ArgBuf = NULL;
 738         StrBuf *ReplyBuf = NULL;
 739         StrBuf *return_to = NULL;
 740         StrBuf *RedirectUrl = NULL;
 741         ctdl_openid *oiddata;
 742         int discovery_succeeded = 0;
 743
 744         if (CtdlGetConfigInt("c_disable_newu")) {
 745                 cprintf("%d this system does not support openid.\n", ERROR + CMD_NOT_SUPPORTED);
 746                 return;
 747         }
 748         Free_ctdl_openid ((ctdl_openid**)&CC->openid_data);
 749
 750         CC->openid_data = oiddata = malloc(sizeof(ctdl_openid));
 751         if (oiddata == NULL) {
 752                 syslog(LOG_ERR, "openid: malloc() failed: %m");
 753                 cprintf("%d malloc failed\n", ERROR + INTERNAL_ERROR);
 754                 return;
 755         }
 756         memset(oiddata, 0, sizeof(ctdl_openid));
 757
 758         ArgBuf = NewStrBufPlain(argbuf, -1);
 759
 760         oiddata->verified = 0;
 761         oiddata->claimed_id = NewStrBufPlain(NULL, StrLength(ArgBuf));
 762         return_to = NewStrBufPlain(NULL, StrLength(ArgBuf));
 763
 764         StrBufExtract_NextToken(oiddata->claimed_id, ArgBuf, &Pos, '|');
 765         StrBufExtract_NextToken(return_to, ArgBuf, &Pos, '|');
 766
 767         syslog(LOG_DEBUG, "openid: user-Supplied Identifier is: %s", ChrPtr(oiddata->claimed_id));
 768
 769         // ********* OpenID 2.0 section 7.3 - Discovery *********
 770
 771         // Section 7.3.1 says we have to attempt XRI based discovery.
 772         // No one is using this, no one is asking for it, no one wants it.
 773         // So we're not even going to bother attempting this mode.
 774
 775         // Attempt section 7.3.2 (Yadis discovery) and section 7.3.3 (HTML discovery);
 776         discovery_succeeded = perform_openid2_discovery(oiddata->claimed_id);
 777
 778         if (discovery_succeeded == 0) {
 779                 cprintf("%d There is no OpenID identity provider at this location.\n", ERROR);
 780         }
 781
 782         else {
 783                 // If we get to this point we are in possession of a valid OpenID Provider URL.
 784                 syslog(LOG_DEBUG, "openid: OP URI '%s' discovered using method %d",
 785                         ChrPtr(oiddata->op_url),
 786                         discovery_succeeded
 787                 );
 788
 789                 // We have to "normalize" our Claimed ID otherwise it will cause some OP's to barf
 790                 if (cbmstrcasestr(ChrPtr(oiddata->claimed_id), "://") == NULL) {
 791                         StrBuf *cid = oiddata->claimed_id;
 792                         oiddata->claimed_id = NewStrBufPlain(HKEY("http://"));
 793                         StrBufAppendBuf(oiddata->claimed_id, cid, 0);
 794                         FreeStrBuf(&cid);
 795                 }
 796
 797                 // OpenID 2.0 section 9: request authentication
 798                 // Assemble a URL to which the user-agent will be redirected.
 799
 800                 RedirectUrl = NewStrBufDup(oiddata->op_url);
 801
 802                 StrBufAppendBufPlain(RedirectUrl, HKEY("?openid.ns="), 0);
 803                 StrBufUrlescAppend(RedirectUrl, NULL, "http://specs.openid.net/auth/2.0");
 804
 805                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.mode=checkid_setup"), 0);
 806
 807                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.claimed_id="), 0);
 808                 StrBufUrlescAppend(RedirectUrl, oiddata->claimed_id, NULL);
 809
 810                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.identity="), 0);
 811                 StrBufUrlescAppend(RedirectUrl, oiddata->claimed_id, NULL);
 812
 813                 // return_to tells the provider how to complete the round trip back to our site
 814                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.return_to="), 0);
 815                 StrBufUrlescAppend(RedirectUrl, return_to, NULL);
 816
 817                 // Attribute Exchange
 818                 // See:
 819                 //      http://openid.net/specs/openid-attribute-exchange-1_0.html
 820                 //      http://code.google.com/apis/accounts/docs/OpenID.html#endpoint
 821                 //      http://test-id.net/OP/AXFetch.aspx
 822
 823                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.ns.ax="), 0);
 824                 StrBufUrlescAppend(RedirectUrl, NULL, "http://openid.net/srv/ax/1.0");
 825
 826                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.ax.mode=fetch_request"), 0);
 827
 828                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.ax.required=firstname,lastname,friendly,nickname"), 0);
 829
 830                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.ax.type.firstname="), 0);
 831                 StrBufUrlescAppend(RedirectUrl, NULL, "http://axschema.org/namePerson/first");
 832
 833                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.ax.type.lastname="), 0);
 834                 StrBufUrlescAppend(RedirectUrl, NULL, "http://axschema.org/namePerson/last");
 835
 836                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.ax.type.friendly="), 0);
 837                 StrBufUrlescAppend(RedirectUrl, NULL, "http://axschema.org/namePerson/friendly");
 838
 839                 StrBufAppendBufPlain(RedirectUrl, HKEY("&openid.ax.type.nickname="), 0);
 840                 StrBufUrlescAppend(RedirectUrl, NULL, "http://axschema.org/namePerson/nickname");
 841
 842                 syslog(LOG_DEBUG, "openid: redirecting client to %s", ChrPtr(RedirectUrl));
 843                 cprintf("%d %s\n", CIT_OK, ChrPtr(RedirectUrl));
 844         }
 845
 846         FreeStrBuf(&ArgBuf);
 847         FreeStrBuf(&ReplyBuf);
 848         FreeStrBuf(&return_to);
 849         FreeStrBuf(&RedirectUrl);
 850 }
 851
 852
 853 // Finalize an OpenID authentication
 854 void cmd_oidf(char *argbuf) {
 855         long len;
 856         char buf[2048];
 857         char thiskey[1024];
 858         char thisdata[1024];
 859         HashList *keys = NULL;
 860         const char *Key;
 861         void *Value;
 862         ctdl_openid *oiddata = (ctdl_openid *) CC->openid_data;
 863
 864         if (CtdlGetConfigInt("c_disable_newu")) {
 865                 cprintf("%d this system does not support openid.\n",
 866                         ERROR + CMD_NOT_SUPPORTED);
 867                 return;
 868         }
 869         if (oiddata == NULL) {
 870                 cprintf("%d run OIDS first.\n", ERROR + INTERNAL_ERROR);
 871                 return;
 872         }
 873         if (StrLength(oiddata->op_url) == 0){
 874                 cprintf("%d No OpenID Endpoint URL has been obtained.\n", ERROR + ILLEGAL_VALUE);
 875                 return;
 876         }
 877         keys = NewHash(1, NULL);
 878         if (!keys) {
 879                 cprintf("%d NewHash() failed\n", ERROR + INTERNAL_ERROR);
 880                 return;
 881         }
 882         cprintf("%d Transmit OpenID data now\n", START_CHAT_MODE);
 883
 884         while (client_getln(buf, sizeof buf), strcmp(buf, "000")) {
 885                 len = extract_token(thiskey, buf, 0, '|', sizeof thiskey);
 886                 if (len < 0) {
 887                         len = sizeof(thiskey) - 1;
 888                 }
 889                 extract_token(thisdata, buf, 1, '|', sizeof thisdata);
 890                 Put(keys, thiskey, len, strdup(thisdata), NULL);
 891         }
 892
 893         // Check to see if this is a correct response.
 894         // Start with verified=1 but then set it to 0 if anything looks wrong.
 895         oiddata->verified = 1;
 896
 897         char *openid_ns = NULL;
 898         if (    (!GetHash(keys, "ns", 2, (void *) &openid_ns))
 899                 || (strcasecmp(openid_ns, "http://specs.openid.net/auth/2.0"))
 900         ) {
 901                 syslog(LOG_DEBUG, "openid: this is not an an OpenID assertion");
 902                 oiddata->verified = 0;
 903         }
 904
 905         char *openid_mode = NULL;
 906         if (    (!GetHash(keys, "mode", 4, (void *) &openid_mode))
 907                 || (strcasecmp(openid_mode, "id_res"))
 908         ) {
 909                 oiddata->verified = 0;
 910         }
 911
 912         char *openid_claimed_id = NULL;
 913         if (GetHash(keys, "claimed_id", 10, (void *) &openid_claimed_id)) {
 914                 FreeStrBuf(&oiddata->claimed_id);
 915                 oiddata->claimed_id = NewStrBufPlain(openid_claimed_id, -1);
 916                 syslog(LOG_DEBUG, "openid: provider is asserting the Claimed ID '%s'", ChrPtr(oiddata->claimed_id));
 917         }
 918
 919         // Validate the assertion against the server
 920         syslog(LOG_DEBUG, "openid: validating...");
 921
 922         CURL *curl;
 923         CURLcode res;
 924         struct curl_httppost *formpost = NULL;
 925         struct curl_httppost *lastptr = NULL;
 926         char errmsg[1024] = "";
 927         StrBuf *ReplyBuf = NewStrBuf();
 928
 929         curl_formadd(&formpost, &lastptr,
 930                 CURLFORM_COPYNAME,      "openid.mode",
 931                 CURLFORM_COPYCONTENTS,  "check_authentication",
 932                 CURLFORM_END
 933         );
 934
 935         HashPos *HashPos = GetNewHashPos(keys, 0);
 936         while (GetNextHashPos(keys, HashPos, &len, &Key, &Value) != 0) {
 937                 if (strcasecmp(Key, "mode")) {
 938                         char k_o_keyname[1024];
 939                         snprintf(k_o_keyname, sizeof k_o_keyname, "openid.%s", (const char *)Key);
 940                         curl_formadd(&formpost, &lastptr,
 941                                 CURLFORM_COPYNAME,      k_o_keyname,
 942                                 CURLFORM_COPYCONTENTS,  (char *)Value,
 943                                 CURLFORM_END
 944                         );
 945                 }
 946         }
 947         DeleteHashPos(&HashPos);
 948
 949         curl = ctdl_openid_curl_easy_init(errmsg);
 950         curl_easy_setopt(curl, CURLOPT_URL, ChrPtr(oiddata->op_url));
 951         curl_easy_setopt(curl, CURLOPT_WRITEDATA, ReplyBuf);
 952         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, CurlFillStrBuf_callback);
 953         curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost);
 954
 955         res = curl_easy_perform(curl);
 956         if (res) {
 957                 syslog(LOG_DEBUG, "openid: cmd_oidf() libcurl error %d: %s", res, errmsg);
 958                 oiddata->verified = 0;
 959         }
 960         curl_easy_cleanup(curl);
 961         curl_formfree(formpost);
 962
 963         if (cbmstrcasestr(ChrPtr(ReplyBuf), "is_valid:true") == NULL) {
 964                 oiddata->verified = 0;
 965         }
 966         FreeStrBuf(&ReplyBuf);
 967
 968         syslog(LOG_DEBUG, "openid: authentication %s", (oiddata->verified ? "succeeded" : "failed") );
 969
 970         // Respond to the client
 971
 972         if (oiddata->verified) {
 973
 974                 // If we were already logged in, attach the OpenID to the user's account
 975                 if (CC->logged_in) {
 976                         if (attach_extauth(&CC->user, oiddata->claimed_id) == 0) {
 977                                 cprintf("attach\n");
 978                                 syslog(LOG_DEBUG, "openid: attach succeeded");
 979                         }
 980                         else {
 981                                 cprintf("fail\n");
 982                                 syslog(LOG_DEBUG, "openid: attach failed");
 983                         }
 984                 }
 985
 986                 // Otherwise, a user is attempting to log in using the verified OpenID
 987                 else {
 988                         // Existing user who has claimed this OpenID?
 989                         //
 990                         // Note: if you think that sending the password back over the wire is insecure,
 991                         // check your assumptions.  If someone has successfully asserted an OpenID that
 992                         // is associated with the account, they already have password equivalency and can
 993                         // login, so they could just as easily change the password, etc.
 994                         if (login_via_extauth(oiddata->claimed_id) == 0) {
 995                                 cprintf("authenticate\n%s\n%s\n", CC->user.fullname, CC->user.password);
 996                                 logged_in_response();
 997                                 syslog(LOG_DEBUG, "openid: logged in using previously claimed OpenID");
 998                         }
 999
1000                         // If this system does not allow self-service new user registration, the
1001                         // remaining modes do not apply, so fail here and now.
1002                         else if (CtdlGetConfigInt("c_disable_newu")) {
1003                                 cprintf("fail\n");
1004                                 syslog(LOG_DEBUG, "openid: creating user failed due to local policy");
1005                         }
1006
1007                         // New user whose OpenID is verified and Attribute Exchange gave us a name?
1008                         else if (openid_create_user_via_ax(oiddata->claimed_id, keys) == 0) {
1009                                 cprintf("authenticate\n%s\n%s\n", CC->user.fullname, CC->user.password);
1010                                 logged_in_response();
1011                                 syslog(LOG_DEBUG, "openid: successfully auto-created new user");
1012                         }
1013
1014                         // OpenID is verified, but the desired username either was not specified or
1015                         // conflicts with an existing user.  Manual account creation is required.
1016                         else {
1017                                 char *desired_name = NULL;
1018                                 cprintf("verify_only\n");
1019                                 cprintf("%s\n", ChrPtr(oiddata->claimed_id));
1020                                 if (GetHash(keys, "sreg.nickname", 13, (void *) &desired_name)) {
1021                                         cprintf("%s\n", desired_name);
1022                                 }
1023                                 else {
1024                                         cprintf("\n");
1025                                 }
1026                                 syslog(LOG_DEBUG, "openid: the desired display name is already taken.");
1027                         }
1028                 }
1029         }
1030         else {
1031                 cprintf("fail\n");
1032         }
1033         cprintf("000\n");
1034
1035         if (oiddata->sreg_keys != NULL) {
1036                 DeleteHash(&oiddata->sreg_keys);
1037                 oiddata->sreg_keys = NULL;
1038         }
1039         oiddata->sreg_keys = keys;
1040 }
1041
1042
1043 // Initialization function, called from modules_init.c
1044 char *ctdl_module_init_openid_rp(void) {
1045         if (!threading) {
1046                 // Only enable the OpenID command set when native mode authentication is in use.
1047                 if (CtdlGetConfigInt("c_auth_mode") == AUTHMODE_NATIVE) {
1048                         CtdlRegisterProtoHook(cmd_oids, "OIDS", "Setup OpenID authentication");
1049                         CtdlRegisterProtoHook(cmd_oidf, "OIDF", "Finalize OpenID authentication");
1050                         CtdlRegisterProtoHook(cmd_oidl, "OIDL", "List OpenIDs associated with an account");
1051                         CtdlRegisterProtoHook(cmd_oidd, "OIDD", "Detach an OpenID from an account");
1052                         CtdlRegisterProtoHook(cmd_oidc, "OIDC", "Create new user after validating OpenID");
1053                         CtdlRegisterProtoHook(cmd_oida, "OIDA", "List all OpenIDs in the database");
1054                 }
1055                 CtdlRegisterSessionHook(openid_cleanup_function, EVT_LOGOUT, PRIO_LOGOUT + 10);
1056                 CtdlRegisterUserHook(extauth_purge, EVT_PURGEUSER);
1057                 openid_level_supported = 2;     // This module supports OpenID 2.0 only
1058         }
1059
1060         // return our module name for the log
1061         return "openid_rp";
1062 }