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 /* This is all disabled temporarily */
  45
  46 #if 0
  47
  48
  49 /**************************************************************************/
  50 /*                                                                        */
  51 /* Functions in this section handle Citadel internal OpenID mapping stuff */
  52 /*                                                                        */
  53 /**************************************************************************/
  54
  55
  56 /*
  57  * The structure of an openid record *key* is:
  58  *
  59  * |--------------claimed_id-------------|
  60  *     (auctual length of claimed id)
  61  *
  62  *
  63  * The structure of an openid record *value* is:
  64  *
  65  * |-----user_number----|------------claimed_id---------------|
  66  *    (sizeof long)          (actual length of claimed id)
  67  *
  68  */
  69
  70
  71 /*
  72  * Attach an OpenID to a Citadel account
  73  */
  74 int attach_openid(struct ctdluser *who, char *claimed_id)
  75 {
  76         struct cdbdata *cdboi;
  77         long fetched_usernum;
  78         char *data;
  79         int data_len;
  80
  81         if (!who) return(1);
  82         if (!claimed_id) return(1);
  83         if (IsEmptyStr(claimed_id)) return(1);
  84
  85         /* Check to see if this OpenID is already in the database */
  86
  87         cdboi = cdb_fetch(CDB_OPENID, claimed_id, strlen(claimed_id));
  88         if (cdboi != NULL) {
  89                 memcpy(&fetched_usernum, cdboi->ptr, sizeof(long));
  90                 cdb_free(cdboi);
  91
  92                 if (fetched_usernum == who->usernum) {
  93                         CtdlLogPrintf(CTDL_INFO, "%s already associated; no action is taken\n", claimed_id);
  94                         return(0);
  95                 }
  96                 else {
  97                         CtdlLogPrintf(CTDL_INFO, "%s already belongs to another user\n", claimed_id);
  98                         return(3);
  99                 }
 100         }
 101
 102         /* Not already in the database, so attach it now */
 103
 104         data_len = sizeof(long) + strlen(claimed_id) + 1;
 105         data = malloc(data_len);
 106
 107         memcpy(data, &who->usernum, sizeof(long));
 108         memcpy(&data[sizeof(long)], claimed_id, strlen(claimed_id) + 1);
 109
 110         cdb_store(CDB_OPENID, claimed_id, strlen(claimed_id), data, data_len);
 111         free(data);
 112
 113         CtdlLogPrintf(CTDL_INFO, "%s has been associated with %s (%ld)\n",
 114                 claimed_id, who->fullname, who->usernum);
 115         return(0);
 116 }
 117
 118
 119 /*
 120  * When a user is being deleted, we have to delete any OpenID associations
 121  */
 122 void openid_purge(struct ctdluser *usbuf) {
 123         /* FIXME finish this */
 124 }
 125
 126
 127
 128 /*
 129  * List the OpenIDs associated with the currently logged in account
 130  */
 131 void cmd_oidl(char *argbuf) {
 132         struct cdbdata *cdboi;
 133
 134         if (CtdlAccessCheck(ac_logged_in)) return;
 135         cdb_rewind(CDB_OPENID);
 136         cprintf("%d Associated OpenIDs:\n", LISTING_FOLLOWS);
 137
 138         while (cdboi = cdb_next_item(CDB_OPENID), cdboi != NULL) {
 139                 if (cdboi->len > sizeof(long)) {
 140                 cprintf("%s\n", cdboi->ptr + sizeof(long));
 141                 }
 142         }
 143         cprintf("000\n");
 144 }
 145
 146
 147
 148
 149 /**************************************************************************/
 150 /*                                                                        */
 151 /* Functions in this section handle OpenID protocol                       */
 152 /*                                                                        */
 153 /**************************************************************************/
 154
 155
 156 /*
 157  * Locate a <link> tag and, given its 'rel=' parameter, return its 'href' parameter
 158  */
 159 void extract_link(char *target_buf, int target_size, char *rel, char *source_buf)
 160 {
 161         char *ptr = source_buf;
 162
 163         if (!target_buf) return;
 164         if (!rel) return;
 165         if (!source_buf) return;
 166
 167         target_buf[0] = 0;
 168
 169         while (ptr = bmstrcasestr(ptr, "<link"), ptr != NULL) {
 170
 171                 char work_buffer[2048];
 172                 char *link_tag_start = NULL;
 173                 char *link_tag_end = NULL;
 174
 175                 char rel_tag[2048];
 176                 char href_tag[2048];
 177
 178                 link_tag_start = ptr;
 179                 link_tag_end = strchr(ptr, '>');
 180                 rel_tag[0] = 0;
 181                 href_tag[0] = 0;
 182
 183                 if ((link_tag_end) && (link_tag_end > link_tag_start)) {
 184                         int len;
 185                         len = link_tag_end - link_tag_start;
 186                         if (len > sizeof work_buffer) len = sizeof work_buffer;
 187                         memcpy(work_buffer, link_tag_start, len);
 188
 189                         char *rel_start = NULL;
 190                         char *rel_end = NULL;
 191                         rel_start = bmstrcasestr(work_buffer, "rel=");
 192                         if (rel_start) {
 193                                 rel_start = strchr(rel_start, '\"');
 194                                 if (rel_start) {
 195                                         ++rel_start;
 196                                         rel_end = strchr(rel_start, '\"');
 197                                         if ((rel_end) && (rel_end > rel_start)) {
 198                                                 safestrncpy(rel_tag, rel_start, rel_end - rel_start + 1);
 199                                         }
 200                                 }
 201                         }
 202
 203                         char *href_start = NULL;
 204                         char *href_end = NULL;
 205                         href_start = bmstrcasestr(work_buffer, "href=");
 206                         if (href_start) {
 207                                 href_start = strchr(href_start, '\"');
 208                                 if (href_start) {
 209                                         ++href_start;
 210                                         href_end = strchr(href_start, '\"');
 211                                         if ((href_end) && (href_end > href_start)) {
 212                                                 safestrncpy(href_tag, href_start, href_end - href_start + 1);
 213                                         }
 214                                 }
 215                         }
 216
 217                         if (!strcasecmp(rel, rel_tag)) {
 218                                 safestrncpy(target_buf, href_tag, target_size);
 219                                 return;
 220                         }
 221
 222                 }
 223
 224         ++ptr;
 225         }
 226
 227
 228 }
 229
 230
 231
 232 struct fh_data {
 233         char *buf;
 234         int total_bytes_received;
 235         int maxbytes;
 236 };
 237
 238
 239 size_t fh_callback(void *ptr, size_t size, size_t nmemb, void *stream)
 240 {
 241         struct fh_data *fh = (struct fh_data *) stream;
 242         int got_bytes = (size * nmemb);
 243
 244         if (fh->total_bytes_received + got_bytes > fh->maxbytes) {
 245                 got_bytes = fh->maxbytes - fh->total_bytes_received;
 246         }
 247         if (got_bytes > 0) {
 248                 memcpy(&fh->buf[fh->total_bytes_received], ptr, got_bytes);
 249                 fh->total_bytes_received += got_bytes;
 250         }
 251
 252         return (size * nmemb);  /* always succeed; libcurl doesn't need to know if we truncated it */
 253 }
 254
 255
 256
 257 /*
 258  * Begin an HTTP fetch (returns number of bytes actually fetched, or -1 for error) using libcurl.
 259  *
 260  * If 'normalize_len' is nonzero, the caller is specifying the buffer size of 'url', and is
 261  * requesting that the effective (normalized) URL be copied back to it.
 262  */
 263 int fetch_http(char *url, char *target_buf, int maxbytes, int normalize_len)
 264 {
 265         CURL *curl;
 266         CURLcode res;
 267         char errmsg[1024] = "";
 268         struct fh_data fh = {
 269                 target_buf,
 270                 0,
 271                 maxbytes
 272         };
 273         char *effective_url = NULL;
 274
 275         if (!url) return(-1);
 276         if (!target_buf) return(-1);
 277         memset(target_buf, 0, maxbytes);
 278
 279         curl = curl_easy_init();
 280         if (!curl) {
 281                 CtdlLogPrintf(CTDL_ALERT, "Unable to initialize libcurl.\n");
 282                 return(-1);
 283         }
 284
 285         curl_easy_setopt(curl, CURLOPT_URL, url);
 286         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0);
 287         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0);
 288         curl_easy_setopt(curl, CURLOPT_WRITEDATA, &fh);
 289         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fh_callback);
 290         curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, errmsg);
 291         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
 292         curl_easy_setopt(curl, CURLOPT_USERAGENT, CITADEL);
 293         if (!IsEmptyStr(config.c_ip_addr)) {
 294                 curl_easy_setopt(curl, CURLOPT_INTERFACE, config.c_ip_addr);
 295         }
 296         res = curl_easy_perform(curl);
 297         if (res) {
 298                 CtdlLogPrintf(CTDL_DEBUG, "fetch_http() libcurl error %d: %s\n", res, errmsg);
 299         }
 300         if (normalize_len > 0) {
 301                 curl_easy_getinfo(curl, CURLINFO_EFFECTIVE_URL, &effective_url);
 302                 safestrncpy(url, effective_url, normalize_len);
 303         }
 304         curl_easy_cleanup(curl);
 305         return fh.total_bytes_received;
 306 }
 307
 308
 309 /*
 310  * Setup an OpenID authentication
 311  */
 312 void cmd_oids(char *argbuf) {
 313         char return_to[1024];
 314         char trust_root[1024];
 315         int i;
 316         char buf[SIZ];
 317         struct CitContext *CCC = CC;    /* CachedCitContext - performance boost */
 318         struct ctdl_openid *oiddata;
 319
 320         /* commented out because we may be attempting to attach an OpenID to
 321          * an existing account that is logged in
 322          *
 323         if (CCC->logged_in) {
 324                 cprintf("%d Already logged in.\n", ERROR + ALREADY_LOGGED_IN);
 325                 return;
 326         }
 327          */
 328
 329         if (CCC->openid_data != NULL) {
 330                 free(CCC->openid_data);
 331         }
 332         oiddata = malloc(sizeof(struct ctdl_openid));
 333         if (oiddata == NULL) {
 334                 cprintf("%d malloc failed\n", ERROR + INTERNAL_ERROR);
 335                 return;
 336         }
 337         memset(oiddata, 0, sizeof(struct ctdl_openid));
 338         CCC->openid_data = (void *) oiddata;
 339
 340         extract_token(oiddata->claimed_id, argbuf, 0, '|', sizeof oiddata->claimed_id);
 341         extract_token(return_to, argbuf, 1, '|', sizeof return_to);
 342         extract_token(trust_root, argbuf, 2, '|', sizeof trust_root);
 343         oiddata->validated = 0;
 344
 345         i = fetch_http(oiddata->claimed_id, buf, sizeof buf - 1, sizeof oiddata->claimed_id);
 346         CtdlLogPrintf(CTDL_DEBUG, "Normalized URL and Claimed ID is: %s\n", oiddata->claimed_id);
 347         buf[sizeof buf - 1] = 0;
 348         if (i > 0) {
 349                 char openid_delegate[1024];
 350
 351                 extract_link(oiddata->server, sizeof oiddata->server, "openid.server", buf);
 352                 extract_link(openid_delegate, sizeof openid_delegate, "openid.delegate", buf);
 353
 354                 if (IsEmptyStr(oiddata->server)) {
 355                         cprintf("%d There is no OpenID identity provider at this URL.\n", ERROR);
 356                         return;
 357                 }
 358
 359                 /* Empty delegate is legal; we just use the openid_url instead */
 360                 if (IsEmptyStr(openid_delegate)) {
 361                         safestrncpy(openid_delegate, oiddata->claimed_id, sizeof openid_delegate);
 362                 }
 363
 364                 /* Assemble a URL to which the user-agent will be redirected. */
 365                 char redirect_string[4096];
 366                 char escaped_identity[512];
 367                 char escaped_return_to[2048];
 368                 char escaped_trust_root[1024];
 369                 char escaped_sreg_optional[256];
 370
 371                 urlesc(escaped_identity, sizeof escaped_identity, openid_delegate);
 372                 urlesc(escaped_return_to, sizeof escaped_return_to, return_to);
 373                 urlesc(escaped_trust_root, sizeof escaped_trust_root, trust_root);
 374                 urlesc(escaped_sreg_optional, sizeof escaped_sreg_optional,
 375                         "nickname,email,fullname,postcode,country");
 376
 377                 snprintf(redirect_string, sizeof redirect_string,
 378                         "%s"
 379                         "?openid.mode=checkid_setup"
 380                         "&openid.identity=%s"
 381                         "&openid.return_to=%s"
 382                         "&openid.trust_root=%s"
 383                         "&openid.sreg.optional=%s"
 384                         ,
 385                         oiddata->server,
 386                         escaped_identity,
 387                         escaped_return_to,
 388                         escaped_trust_root,
 389                         escaped_sreg_optional
 390                 );
 391                 cprintf("%d %s\n", CIT_OK, redirect_string);
 392                 return;
 393         }
 394
 395         cprintf("%d Unable to fetch OpenID URL\n", ERROR);
 396 }
 397
 398
 399
 400 /*
 401  * Callback function to free a pointer (used below in the hash list)
 402  */
 403 void free_oid_key(void *ptr) {
 404         free(ptr);
 405 }
 406
 407
 408 /*
 409  * Finalize an OpenID authentication
 410  */
 411 void cmd_oidf(char *argbuf) {
 412         char buf[2048];
 413         char thiskey[1024];
 414         char thisdata[1024];
 415         HashList *keys = NULL;
 416         HashPos *HashPos;
 417         struct ctdl_openid *oiddata = (struct ctdl_openid *) CC->openid_data;
 418
 419         keys = NewHash(1, NULL);
 420         if (!keys) {
 421                 cprintf("%d NewHash() failed\n", ERROR + INTERNAL_ERROR);
 422                 return;
 423         }
 424
 425         cprintf("%d Transmit OpenID data now\n", START_CHAT_MODE);
 426
 427         while (client_getln(buf, sizeof buf), strcmp(buf, "000")) {
 428                 extract_token(thiskey, buf, 0, '|', sizeof thiskey);
 429                 extract_token(thisdata, buf, 1, '|', sizeof thisdata);
 430                 CtdlLogPrintf(CTDL_DEBUG, "%s: [%d] %s\n", thiskey, strlen(thisdata), thisdata);
 431                 Put(keys, thiskey, strlen(thiskey), strdup(thisdata), free_oid_key);
 432         }
 433
 434
 435         /* Now that we have all of the parameters, we have to validate the signature against the server */
 436         CtdlLogPrintf(CTDL_DEBUG, "About to validate the signature...\n");
 437
 438         CURL *curl;
 439         CURLcode res;
 440         struct curl_httppost *formpost = NULL;
 441         struct curl_httppost *lastptr = NULL;
 442         char errmsg[1024] = "";
 443         char *o_assoc_handle = NULL;
 444         char *o_sig = NULL;
 445         char *o_signed = NULL;
 446         int num_signed_values;
 447         int i;
 448         char k_keyname[128];
 449         char k_o_keyname[128];
 450         char *k_value = NULL;
 451         char valbuf[1024];
 452
 453         struct fh_data fh = {
 454                 valbuf,
 455                 0,
 456                 sizeof valbuf
 457         };
 458
 459         curl_formadd(&formpost, &lastptr,
 460                 CURLFORM_COPYNAME,      "openid.mode",
 461                 CURLFORM_COPYCONTENTS,  "check_authentication",
 462                 CURLFORM_END);
 463         CtdlLogPrintf(CTDL_DEBUG, "%25s : %s\n", "openid.mode", "check_authentication");
 464
 465         if (GetHash(keys, "assoc_handle", 12, (void *) &o_assoc_handle)) {
 466                 curl_formadd(&formpost, &lastptr,
 467                         CURLFORM_COPYNAME,      "openid.assoc_handle",
 468                         CURLFORM_COPYCONTENTS,  o_assoc_handle,
 469                         CURLFORM_END);
 470                 CtdlLogPrintf(CTDL_DEBUG, "%25s : %s\n", "openid.assoc_handle", o_assoc_handle);
 471         }
 472
 473         if (GetHash(keys, "sig", 3, (void *) &o_sig)) {
 474                 curl_formadd(&formpost, &lastptr,
 475                         CURLFORM_COPYNAME,      "openid.sig",
 476                         CURLFORM_COPYCONTENTS,  o_sig,
 477                         CURLFORM_END);
 478                         CtdlLogPrintf(CTDL_DEBUG, "%25s : %s\n", "openid.sig", o_sig);
 479         }
 480
 481         if (GetHash(keys, "signed", 6, (void *) &o_signed)) {
 482                 curl_formadd(&formpost, &lastptr,
 483                         CURLFORM_COPYNAME,      "openid.signed",
 484                         CURLFORM_COPYCONTENTS,  o_signed,
 485                         CURLFORM_END);
 486                 CtdlLogPrintf(CTDL_DEBUG, "%25s : %s\n", "openid.signed", o_signed);
 487
 488                 num_signed_values = num_tokens(o_signed, ',');
 489                 for (i=0; i<num_signed_values; ++i) {
 490                         extract_token(k_keyname, o_signed, i, ',', sizeof k_keyname);
 491                         if (strcasecmp(k_keyname, "mode")) {    // work around phpMyID bug
 492                                 if (GetHash(keys, k_keyname, strlen(k_keyname), (void *) &k_value)) {
 493                                         snprintf(k_o_keyname, sizeof k_o_keyname, "openid.%s", k_keyname);
 494                                         curl_formadd(&formpost, &lastptr,
 495                                                 CURLFORM_COPYNAME,      k_o_keyname,
 496                                                 CURLFORM_COPYCONTENTS,  k_value,
 497                                                 CURLFORM_END);
 498                                         CtdlLogPrintf(CTDL_DEBUG, "%25s : %s\n", k_o_keyname, k_value);
 499                                 }
 500                                 else {
 501                                         CtdlLogPrintf(CTDL_INFO, "OpenID: signed field '%s' is missing\n",
 502                                                 k_keyname);
 503                                 }
 504                         }
 505                 }
 506         }
 507
 508         curl = curl_easy_init();
 509         curl_easy_setopt(curl, CURLOPT_URL, oiddata->server);
 510         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0);
 511         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0);
 512         curl_easy_setopt(curl, CURLOPT_WRITEDATA, &fh);
 513         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fh_callback);
 514         curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost);
 515         curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, errmsg);
 516         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
 517         curl_easy_setopt(curl, CURLOPT_USERAGENT, CITADEL);
 518         if (!IsEmptyStr(config.c_ip_addr)) {
 519                 curl_easy_setopt(curl, CURLOPT_INTERFACE, config.c_ip_addr);
 520         }
 521
 522         res = curl_easy_perform(curl);
 523         if (res) {
 524                 CtdlLogPrintf(CTDL_DEBUG, "cmd_oidf() libcurl error %d: %s\n", res, errmsg);
 525         }
 526         curl_easy_cleanup(curl);
 527         curl_formfree(formpost);
 528
 529         valbuf[fh.total_bytes_received] = 0;
 530
 531         if (bmstrcasestr(valbuf, "is_valid:true")) {
 532                 oiddata->validated = 1;
 533         }
 534
 535         CtdlLogPrintf(CTDL_DEBUG, "Authentication %s.\n", (oiddata->validated ? "succeeded" : "failed") );
 536
 537         /* Respond to the client */
 538
 539         if (oiddata->validated) {
 540
 541                 /* If we were already logged in, attach the OpenID to the user's account */
 542                 if (CC->logged_in) {
 543                         if (attach_openid(&CC->user, oiddata->claimed_id) == 0) {
 544                                 cprintf("attach\n");
 545                         }
 546                         else {
 547                                 cprintf("fail\n");
 548                         }
 549                 }
 550
 551                 /* Otherwise, a user is attempting to log in using the validated OpenID */
 552                 else {
 553                         cprintf("fail\n");              // FIXME do the login here!!
 554                 }
 555
 556         }
 557         else {
 558                 cprintf("fail\n");
 559         }
 560         cprintf("000\n");
 561
 562         /* Free the hash list */
 563         long len;
 564         void *Value;
 565         char *Key;
 566
 567         HashPos = GetNewHashPos();
 568         while (GetNextHashPos(keys, HashPos, &len, &Key, &Value)!=0)
 569         {
 570                 free(Value);
 571         }
 572         DeleteHashPos(&HashPos);
 573 }
 574
 575
 576 // mode = [6]  id_res
 577 // identity = [50]  http://uncensored.citadel.org/~ajc/MyID.config.php
 578 // assoc_handle = [26]  6ekac3ju181tgepk7v4h9r7ui7
 579 // return_to = [42]  http://jemcaterers.net/finish_openid_login
 580 // sreg.nickname = [17]  IGnatius T Foobar
 581 // sreg.email = [26]  ajc@uncensored.citadel.org
 582 // sreg.fullname = [10]  Art Cancro
 583 // sreg.postcode = [5]  10549
 584 // sreg.country = [2]  US
 585 // signed = [102]  mode,identity,assoc_handle,return_to,sreg.nickname,sreg.email,sreg.fullname,sreg.postcode,sreg.country
 586 // sig = [28]  vixxxU4MAqWfxxxxCfrHv3TxxxhEw=
 587
 588
 589
 590
 591 /**************************************************************************/
 592 /*                                                                        */
 593 /* Functions in this section handle module initialization and shutdown    */
 594 /*                                                                        */
 595 /**************************************************************************/
 596
 597
 598 /*
 599  * This cleanup function blows away the temporary memory used by this module.
 600  */
 601 void openid_cleanup_function(void) {
 602
 603         if (CC->openid_data != NULL) {
 604                 free(CC->openid_data);
 605         }
 606 }
 607
 608
 609 CTDL_MODULE_INIT(openid_rp)
 610 {
 611         if (!threading)
 612         {
 613                 curl_global_init(CURL_GLOBAL_ALL);
 614                 CtdlRegisterProtoHook(cmd_oids, "OIDS", "Setup OpenID authentication");
 615                 CtdlRegisterProtoHook(cmd_oidf, "OIDF", "Finalize OpenID authentication");
 616                 CtdlRegisterProtoHook(cmd_oidl, "OIDL", "List OpenIDs associated with an account");
 617                 CtdlRegisterSessionHook(openid_cleanup_function, EVT_STOP);
 618                 CtdlRegisterUserHook(openid_purge, EVT_PURGEUSER);
 619         }
 620
 621         /* return our Subversion id for the Log */
 622         return "$Id$";
 623 }
 624
 625
 626 /* FIXME ... we have to add the new openid database to serv_vandelay.c */
 627
 628
 629 #endif
 630 CTDL_MODULE_INIT(openid_rp)
 631 {
 632         return "$Id$";
 633 }