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