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