citadel/modules/openid/serv_openid_rp.c

   1 /*
   2  * $Id$
   3  *
   4  * This is an implementation of OpenID 1.1 Relying Party support, in stateless mode.
   5  *
   6  */
   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
  18 #if TIME_WITH_SYS_TIME
  19 # include <sys/time.h>
  20 # include <time.h>
  21 #else
  22 # if HAVE_SYS_TIME_H
  23 #  include <sys/time.h>
  24 # else
  25 #  include <time.h>
  26 # endif
  27 #endif
  28
  29 #include <sys/wait.h>
  30 #include <string.h>
  31 #include <limits.h>
  32 #include <curl/curl.h>
  33 #include "ctdl_module.h"
  34 #include "config.h"
  35 #include "citserver.h"
  36
  37 struct ctdl_openid {
  38         char claimed_id[1024];
  39         char server[1024];
  40         int validated;
  41 };
  42
  43
  44
  45
  46
  47 /**************************************************************************/
  48 /*                                                                        */
  49 /* Functions in this section handle Citadel internal OpenID mapping stuff */
  50 /*                                                                        */
  51 /**************************************************************************/
  52
  53
  54 /*
  55  * The structure of an openid record *key* is:
  56  *
  57  * |--------------claimed_id-------------|
  58  *     (auctual length of claimed id)
  59  *
  60  *
  61  * The structure of an openid record *value* is:
  62  *
  63  * |-----user_number----|------------claimed_id---------------|
  64  *    (sizeof long)          (actual length of claimed id)
  65  *
  66  */
  67
  68
  69 /*
  70  * Attach an OpenID to a Citadel account
  71  */
  72 int attach_openid(struct ctdluser *who, char *claimed_id)
  73 {
  74         struct cdbdata *cdboi;
  75         long fetched_usernum;
  76         char *data;
  77         int data_len;
  78
  79         if (!who) return(1);
  80         if (!claimed_id) return(1);
  81         if (IsEmptyStr(claimed_id)) return(1);
  82
  83         /* Check to see if this OpenID is already in the database */
  84
  85         cdboi = cdb_fetch(CDB_OPENID, claimed_id, strlen(claimed_id));
  86         if (cdboi != NULL) {
  87                 memcpy(&fetched_usernum, cdboi->ptr, sizeof(long));
  88                 cdb_free(cdboi);
  89
  90                 if (fetched_usernum == who->usernum) {
  91                         CtdlLogPrintf(CTDL_INFO, "%s already associated; no action is taken\n", claimed_id);
  92                         return(0);
  93                 }
  94                 else {
  95                         CtdlLogPrintf(CTDL_INFO, "%s already belongs to another user\n", claimed_id);
  96                         return(3);
  97                 }
  98         }
  99
 100         /* Not already in the database, so attach it now */
 101
 102         data_len = sizeof(long) + strlen(claimed_id) + 1;
 103         data = malloc(data_len);
 104
 105         memcpy(data, &who->usernum, sizeof(long));
 106         memcpy(&data[sizeof(long)], claimed_id, strlen(claimed_id) + 1);
 107
 108         cdb_store(CDB_OPENID, claimed_id, strlen(claimed_id), data, data_len);
 109         free(data);
 110
 111         CtdlLogPrintf(CTDL_INFO, "%s has been associated with %s (%ld)\n",
 112                 claimed_id, who->fullname, who->usernum);
 113         return(0);
 114 }
 115
 116
 117 /*
 118  * When a user is being deleted, we have to delete any OpenID associations
 119  */
 120 void openid_purge(struct ctdluser *usbuf) {
 121         /* FIXME finish this */
 122 }
 123
 124
 125
 126 /*
 127  * List the OpenIDs associated with the currently logged in account
 128  */
 129 void cmd_oidl(char *argbuf) {
 130         struct cdbdata *cdboi;
 131
 132         if (CtdlAccessCheck(ac_logged_in)) return;
 133         cdb_rewind(CDB_OPENID);
 134         cprintf("%d Associated OpenIDs:\n", LISTING_FOLLOWS);
 135
 136         while (cdboi = cdb_next_item(CDB_OPENID), cdboi != NULL) {
 137                 if (cdboi->len > sizeof(long)) {
 138                 cprintf("%s\n", cdboi->ptr + sizeof(long));
 139                 }
 140         }
 141         cprintf("000\n");
 142 }
 143
 144
 145
 146
 147 /**************************************************************************/
 148 /*                                                                        */
 149 /* Functions in this section handle OpenID protocol                       */
 150 /*                                                                        */
 151 /**************************************************************************/
 152
 153
 154 /*
 155  * Locate a <link> tag and, given its 'rel=' parameter, return its 'href' parameter
 156  */
 157 void extract_link(char *target_buf, int target_size, char *rel, char *source_buf)
 158 {
 159         char *ptr = source_buf;
 160
 161         if (!target_buf) return;
 162         if (!rel) return;
 163         if (!source_buf) return;
 164
 165         target_buf[0] = 0;
 166
 167         while (ptr = bmstrcasestr(ptr, "<link"), ptr != NULL) {
 168
 169                 char work_buffer[2048];
 170                 char *link_tag_start = NULL;
 171                 char *link_tag_end = NULL;
 172
 173                 char rel_tag[2048];
 174                 char href_tag[2048];
 175
 176                 link_tag_start = ptr;
 177                 link_tag_end = strchr(ptr, '>');
 178                 rel_tag[0] = 0;
 179                 href_tag[0] = 0;
 180
 181                 if ((link_tag_end) && (link_tag_end > link_tag_start)) {
 182                         int len;
 183                         len = link_tag_end - link_tag_start;
 184                         if (len > sizeof work_buffer) len = sizeof work_buffer;
 185                         memcpy(work_buffer, link_tag_start, len);
 186
 187                         char *rel_start = NULL;
 188                         char *rel_end = NULL;
 189                         rel_start = bmstrcasestr(work_buffer, "rel=");
 190                         if (rel_start) {
 191                                 rel_start = strchr(rel_start, '\"');
 192                                 if (rel_start) {
 193                                         ++rel_start;
 194                                         rel_end = strchr(rel_start, '\"');
 195                                         if ((rel_end) && (rel_end > rel_start)) {
 196                                                 safestrncpy(rel_tag, rel_start, rel_end - rel_start + 1);
 197                                         }
 198                                 }
 199                         }
 200
 201                         char *href_start = NULL;
 202                         char *href_end = NULL;
 203                         href_start = bmstrcasestr(work_buffer, "href=");
 204                         if (href_start) {
 205                                 href_start = strchr(href_start, '\"');
 206                                 if (href_start) {
 207                                         ++href_start;
 208                                         href_end = strchr(href_start, '\"');
 209                                         if ((href_end) && (href_end > href_start)) {
 210                                                 safestrncpy(href_tag, href_start, href_end - href_start + 1);
 211                                         }
 212                                 }
 213                         }
 214
 215                         if (!strcasecmp(rel, rel_tag)) {
 216                                 safestrncpy(target_buf, href_tag, target_size);
 217                                 return;
 218                         }
 219
 220                 }
 221
 222         ++ptr;
 223         }
 224
 225
 226 }
 227
 228
 229
 230 struct fh_data {
 231         char *buf;
 232         int total_bytes_received;
 233         int maxbytes;
 234 };
 235
 236
 237 size_t fh_callback(void *ptr, size_t size, size_t nmemb, void *stream)
 238 {
 239         struct fh_data *fh = (struct fh_data *) stream;
 240         int got_bytes = (size * nmemb);
 241
 242         if (fh->total_bytes_received + got_bytes > fh->maxbytes) {
 243                 got_bytes = fh->maxbytes - fh->total_bytes_received;
 244         }
 245         if (got_bytes > 0) {
 246                 memcpy(&fh->buf[fh->total_bytes_received], ptr, got_bytes);
 247                 fh->total_bytes_received += got_bytes;
 248         }
 249
 250         return (size * nmemb);  /* always succeed; libcurl doesn't need to know if we truncated it */
 251 }
 252
 253
 254
 255 /*
 256  * Begin an HTTP fetch (returns number of bytes actually fetched, or -1 for error) using libcurl.
 257  *
 258  * If 'normalize_len' is nonzero, the caller is specifying the buffer size of 'url', and is
 259  * requesting that the effective (normalized) URL be copied back to it.
 260  */
 261 int fetch_http(char *url, char *target_buf, int maxbytes, int normalize_len)
 262 {
 263         CURL *curl;
 264         CURLcode res;
 265         char errmsg[1024] = "";
 266         struct fh_data fh = {
 267                 target_buf,
 268                 0,
 269                 maxbytes
 270         };
 271         char *effective_url = NULL;
 272
 273         if (!url) return(-1);
 274         if (!target_buf) return(-1);
 275         memset(target_buf, 0, maxbytes);
 276
 277         curl = curl_easy_init();
 278         if (!curl) {
 279                 CtdlLogPrintf(CTDL_ALERT, "Unable to initialize libcurl.\n");
 280                 return(-1);
 281         }
 282
 283         curl_easy_setopt(curl, CURLOPT_URL, url);
 284         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0);
 285         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0);
 286         curl_easy_setopt(curl, CURLOPT_WRITEDATA, &fh);
 287         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fh_callback);
 288         curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, errmsg);
 289         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
 290         curl_easy_setopt(curl, CURLOPT_USERAGENT, CITADEL);
 291         if (!IsEmptyStr(config.c_ip_addr)) {
 292                 curl_easy_setopt(curl, CURLOPT_INTERFACE, config.c_ip_addr);
 293         }
 294         res = curl_easy_perform(curl);
 295         if (res) {
 296                 CtdlLogPrintf(CTDL_DEBUG, "fetch_http() libcurl error %d: %s\n", res, errmsg);
 297         }
 298         if (normalize_len > 0) {
 299                 curl_easy_getinfo(curl, CURLINFO_EFFECTIVE_URL, &effective_url);
 300                 safestrncpy(url, effective_url, normalize_len);
 301         }
 302         curl_easy_cleanup(curl);
 303         return fh.total_bytes_received;
 304 }
 305
 306
 307 /*
 308  * Setup an OpenID authentication
 309  */
 310 void cmd_oids(char *argbuf) {
 311         char return_to[1024];
 312         char trust_root[1024];
 313         int i;
 314         char buf[SIZ];
 315         struct CitContext *CCC = CC;    /* CachedCitContext - performance boost */
 316         struct ctdl_openid *oiddata;
 317
 318         /* commented out because we may be attempting to attach an OpenID to
 319          * an existing account that is logged in
 320          *
 321         if (CCC->logged_in) {
 322                 cprintf("%d Already logged in.\n", ERROR + ALREADY_LOGGED_IN);
 323                 return;
 324         }
 325          */
 326
 327         if (CCC->openid_data != NULL) {
 328                 free(CCC->openid_data);
 329         }
 330         oiddata = malloc(sizeof(struct ctdl_openid));
 331         if (oiddata == NULL) {
 332                 cprintf("%d malloc failed\n", ERROR + INTERNAL_ERROR);
 333                 return;
 334         }
 335         memset(oiddata, 0, sizeof(struct ctdl_openid));
 336         CCC->openid_data = (void *) oiddata;
 337
 338         extract_token(oiddata->claimed_id, argbuf, 0, '|', sizeof oiddata->claimed_id);
 339         extract_token(return_to, argbuf, 1, '|', sizeof return_to);
 340         extract_token(trust_root, argbuf, 2, '|', sizeof trust_root);
 341         oiddata->validated = 0;
 342
 343         i = fetch_http(oiddata->claimed_id, buf, sizeof buf - 1, sizeof oiddata->claimed_id);
 344         CtdlLogPrintf(CTDL_DEBUG, "Normalized URL and Claimed ID is: %s\n", oiddata->claimed_id);
 345         buf[sizeof buf - 1] = 0;
 346         if (i > 0) {
 347                 char openid_delegate[1024];
 348
 349                 extract_link(oiddata->server, sizeof oiddata->server, "openid.server", buf);
 350                 extract_link(openid_delegate, sizeof openid_delegate, "openid.delegate", buf);
 351
 352                 if (IsEmptyStr(oiddata->server)) {
 353                         cprintf("%d There is no OpenID identity provider at this URL.\n", ERROR);
 354                         return;
 355                 }
 356
 357                 /* Empty delegate is legal; we just use the openid_url instead */
 358                 if (IsEmptyStr(openid_delegate)) {
 359                         safestrncpy(openid_delegate, oiddata->claimed_id, sizeof openid_delegate);
 360                 }
 361
 362                 /* Assemble a URL to which the user-agent will be redirected. */
 363                 char redirect_string[4096];
 364                 char escaped_identity[512];
 365                 char escaped_return_to[2048];
 366                 char escaped_trust_root[1024];
 367                 char escaped_sreg_optional[256];
 368
 369                 urlesc(escaped_identity, sizeof escaped_identity, openid_delegate);
 370                 urlesc(escaped_return_to, sizeof escaped_return_to, return_to);
 371                 urlesc(escaped_trust_root, sizeof escaped_trust_root, trust_root);
 372                 urlesc(escaped_sreg_optional, sizeof escaped_sreg_optional,
 373                         "nickname,email,fullname,postcode,country");
 374
 375                 snprintf(redirect_string, sizeof redirect_string,
 376                         "%s"
 377                         "?openid.mode=checkid_setup"
 378                         "&openid.identity=%s"
 379                         "&openid.return_to=%s"
 380                         "&openid.trust_root=%s"
 381                         "&openid.sreg.optional=%s"
 382                         ,
 383                         oiddata->server,
 384                         escaped_identity,
 385                         escaped_return_to,
 386                         escaped_trust_root,
 387                         escaped_sreg_optional
 388                 );
 389                 cprintf("%d %s\n", CIT_OK, redirect_string);
 390                 return;
 391         }
 392
 393         cprintf("%d Unable to fetch OpenID URL\n", ERROR);
 394 }
 395
 396
 397
 398 /*
 399  * Callback function to free a pointer (used below in the hash list)
 400  */
 401 void free_oid_key(void *ptr) {
 402         free(ptr);
 403 }
 404
 405
 406 /*
 407  * Finalize an OpenID authentication
 408  */
 409 void cmd_oidf(char *argbuf) {
 410         char buf[2048];
 411         char thiskey[1024];
 412         char thisdata[1024];
 413         HashList *keys = NULL;
 414         HashPos *HashPos;
 415         struct ctdl_openid *oiddata = (struct ctdl_openid *) CC->openid_data;
 416
 417         keys = NewHash(1, NULL);
 418         if (!keys) {
 419                 cprintf("%d NewHash() failed\n", ERROR + INTERNAL_ERROR);
 420                 return;
 421         }
 422
 423         cprintf("%d Transmit OpenID data now\n", START_CHAT_MODE);
 424
 425         while (client_getln(buf, sizeof buf), strcmp(buf, "000")) {
 426                 extract_token(thiskey, buf, 0, '|', sizeof thiskey);
 427                 extract_token(thisdata, buf, 1, '|', sizeof thisdata);
 428                 CtdlLogPrintf(CTDL_DEBUG, "%s: [%d] %s\n", thiskey, strlen(thisdata), thisdata);
 429                 Put(keys, thiskey, strlen(thiskey), strdup(thisdata), free_oid_key);
 430         }
 431
 432
 433         /* Now that we have all of the parameters, we have to validate the signature against the server */
 434         CtdlLogPrintf(CTDL_DEBUG, "About to validate the signature...\n");
 435
 436         CURL *curl;
 437         CURLcode res;
 438         struct curl_httppost *formpost = NULL;
 439         struct curl_httppost *lastptr = NULL;
 440         char errmsg[1024] = "";
 441         char *o_assoc_handle = NULL;
 442         char *o_sig = NULL;
 443         char *o_signed = NULL;
 444         int num_signed_values;
 445         int i;
 446         char k_keyname[128];
 447         char k_o_keyname[128];
 448         char *k_value = NULL;
 449         char valbuf[1024];
 450
 451         struct fh_data fh = {
 452                 valbuf,
 453                 0,
 454                 sizeof valbuf
 455         };
 456
 457         curl_formadd(&formpost, &lastptr,
 458                 CURLFORM_COPYNAME,      "openid.mode",
 459                 CURLFORM_COPYCONTENTS,  "check_authentication",
 460                 CURLFORM_END);
 461         CtdlLogPrintf(CTDL_DEBUG, "%25s : %s\n", "openid.mode", "check_authentication");
 462
 463         if (GetHash(keys, "assoc_handle", 12, (void *) &o_assoc_handle)) {
 464                 curl_formadd(&formpost, &lastptr,
 465                         CURLFORM_COPYNAME,      "openid.assoc_handle",
 466                         CURLFORM_COPYCONTENTS,  o_assoc_handle,
 467                         CURLFORM_END);
 468                 CtdlLogPrintf(CTDL_DEBUG, "%25s : %s\n", "openid.assoc_handle", o_assoc_handle);
 469         }
 470
 471         if (GetHash(keys, "sig", 3, (void *) &o_sig)) {
 472                 curl_formadd(&formpost, &lastptr,
 473                         CURLFORM_COPYNAME,      "openid.sig",
 474                         CURLFORM_COPYCONTENTS,  o_sig,
 475                         CURLFORM_END);
 476                         CtdlLogPrintf(CTDL_DEBUG, "%25s : %s\n", "openid.sig", o_sig);
 477         }
 478
 479         if (GetHash(keys, "signed", 6, (void *) &o_signed)) {
 480                 curl_formadd(&formpost, &lastptr,
 481                         CURLFORM_COPYNAME,      "openid.signed",
 482                         CURLFORM_COPYCONTENTS,  o_signed,
 483                         CURLFORM_END);
 484                 CtdlLogPrintf(CTDL_DEBUG, "%25s : %s\n", "openid.signed", o_signed);
 485
 486                 num_signed_values = num_tokens(o_signed, ',');
 487                 for (i=0; i<num_signed_values; ++i) {
 488                         extract_token(k_keyname, o_signed, i, ',', sizeof k_keyname);
 489                         if (strcasecmp(k_keyname, "mode")) {    // work around phpMyID bug
 490                                 if (GetHash(keys, k_keyname, strlen(k_keyname), (void *) &k_value)) {
 491                                         snprintf(k_o_keyname, sizeof k_o_keyname, "openid.%s", k_keyname);
 492                                         curl_formadd(&formpost, &lastptr,
 493                                                 CURLFORM_COPYNAME,      k_o_keyname,
 494                                                 CURLFORM_COPYCONTENTS,  k_value,
 495                                                 CURLFORM_END);
 496                                         CtdlLogPrintf(CTDL_DEBUG, "%25s : %s\n", k_o_keyname, k_value);
 497                                 }
 498                                 else {
 499                                         CtdlLogPrintf(CTDL_INFO, "OpenID: signed field '%s' is missing\n",
 500                                                 k_keyname);
 501                                 }
 502                         }
 503                 }
 504         }
 505
 506         curl = curl_easy_init();
 507         curl_easy_setopt(curl, CURLOPT_URL, oiddata->server);
 508         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0);
 509         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0);
 510         curl_easy_setopt(curl, CURLOPT_WRITEDATA, &fh);
 511         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fh_callback);
 512         curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost);
 513         curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, errmsg);
 514         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
 515         curl_easy_setopt(curl, CURLOPT_USERAGENT, CITADEL);
 516         if (!IsEmptyStr(config.c_ip_addr)) {
 517                 curl_easy_setopt(curl, CURLOPT_INTERFACE, config.c_ip_addr);
 518         }
 519
 520         res = curl_easy_perform(curl);
 521         if (res) {
 522                 CtdlLogPrintf(CTDL_DEBUG, "cmd_oidf() libcurl error %d: %s\n", res, errmsg);
 523         }
 524         curl_easy_cleanup(curl);
 525         curl_formfree(formpost);
 526
 527         valbuf[fh.total_bytes_received] = 0;
 528
 529         if (bmstrcasestr(valbuf, "is_valid:true")) {
 530                 oiddata->validated = 1;
 531         }
 532
 533         CtdlLogPrintf(CTDL_DEBUG, "Authentication %s.\n", (oiddata->validated ? "succeeded" : "failed") );
 534
 535         /* Respond to the client */
 536
 537         if (oiddata->validated) {
 538
 539                 /* If we were already logged in, attach the OpenID to the user's account */
 540                 if (CC->logged_in) {
 541                         if (attach_openid(&CC->user, oiddata->claimed_id) == 0) {
 542                                 cprintf("attach\n");
 543                         }
 544                         else {
 545                                 cprintf("fail\n");
 546                         }
 547                 }
 548
 549                 /* Otherwise, a user is attempting to log in using the validated OpenID */
 550                 else {
 551                         cprintf("fail\n");              // FIXME do the login here!!
 552                 }
 553
 554         }
 555         else {
 556                 cprintf("fail\n");
 557         }
 558         cprintf("000\n");
 559
 560         /* Free the hash list */
 561         long len;
 562         void *Value;
 563         char *Key;
 564
 565         HashPos = GetNewHashPos();
 566         while (GetNextHashPos(keys, HashPos, &len, &Key, &Value)!=0)
 567         {
 568                 free(Value);
 569         }
 570         DeleteHashPos(&HashPos);
 571 }
 572
 573
 574 // mode = [6]  id_res
 575 // identity = [50]  http://uncensored.citadel.org/~ajc/MyID.config.php
 576 // assoc_handle = [26]  6ekac3ju181tgepk7v4h9r7ui7
 577 // return_to = [42]  http://jemcaterers.net/finish_openid_login
 578 // sreg.nickname = [17]  IGnatius T Foobar
 579 // sreg.email = [26]  ajc@uncensored.citadel.org
 580 // sreg.fullname = [10]  Art Cancro
 581 // sreg.postcode = [5]  10549
 582 // sreg.country = [2]  US
 583 // signed = [102]  mode,identity,assoc_handle,return_to,sreg.nickname,sreg.email,sreg.fullname,sreg.postcode,sreg.country
 584 // sig = [28]  vixxxU4MAqWfxxxxCfrHv3TxxxhEw=
 585
 586
 587
 588
 589 /**************************************************************************/
 590 /*                                                                        */
 591 /* Functions in this section handle module initialization and shutdown    */
 592 /*                                                                        */
 593 /**************************************************************************/
 594
 595
 596 /*
 597  * This cleanup function blows away the temporary memory used by this module.
 598  */
 599 void openid_cleanup_function(void) {
 600
 601         if (CC->openid_data != NULL) {
 602                 free(CC->openid_data);
 603         }
 604 }
 605
 606
 607 CTDL_MODULE_INIT(openid_rp)
 608 {
 609         if (!threading)
 610         {
 611                 curl_global_init(CURL_GLOBAL_ALL);
 612                 CtdlRegisterProtoHook(cmd_oids, "OIDS", "Setup OpenID authentication");
 613                 CtdlRegisterProtoHook(cmd_oidf, "OIDF", "Finalize OpenID authentication");
 614                 CtdlRegisterProtoHook(cmd_oidl, "OIDL", "List OpenIDs associated with an account");
 615                 CtdlRegisterSessionHook(openid_cleanup_function, EVT_STOP);
 616                 CtdlRegisterUserHook(openid_purge, EVT_PURGEUSER);
 617         }
 618
 619         /* return our Subversion id for the Log */
 620         return "$Id$";
 621 }
 622
 623
 624 /* FIXME ... we have to add the new openid database to serv_vandelay.c */
 625