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