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