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         res = curl_easy_perform(curl);
 178         if (res) {
 179                 CtdlLogPrintf(CTDL_DEBUG, "fetch_http() libcurl error %d: %s\n", res, errmsg);
 180         }
 181         if (normalize_len > 0) {
 182                 curl_easy_getinfo(curl, CURLINFO_EFFECTIVE_URL, &effective_url);
 183                 safestrncpy(url, effective_url, normalize_len);
 184         }
 185         curl_easy_cleanup(curl);
 186         return fh.total_bytes_received;
 187 }
 188
 189
 190 /*
 191  * Setup an OpenID authentication
 192  */
 193 void cmd_oids(char *argbuf) {
 194         char return_to[1024];
 195         char trust_root[1024];
 196         int i;
 197         char buf[SIZ];
 198         struct CitContext *CCC = CC;    /* CachedCitContext - performance boost */
 199         struct ctdl_openid *oiddata;
 200
 201         if (CCC->logged_in) {
 202                 cprintf("%d Already logged in.\n", ERROR + ALREADY_LOGGED_IN);
 203                 return;
 204         }
 205
 206         if (CCC->openid_data != NULL) {
 207                 free(CCC->openid_data);
 208         }
 209         oiddata = malloc(sizeof(struct ctdl_openid));
 210         if (oiddata == NULL) {
 211                 cprintf("%d malloc failed\n", ERROR + INTERNAL_ERROR);
 212                 return;
 213         }
 214         memset(oiddata, 0, sizeof(struct ctdl_openid));
 215         CCC->openid_data = (void *) oiddata;
 216
 217         extract_token(oiddata->claimed_id, argbuf, 0, '|', sizeof oiddata->claimed_id);
 218         extract_token(return_to, argbuf, 1, '|', sizeof return_to);
 219         extract_token(trust_root, argbuf, 2, '|', sizeof trust_root);
 220
 221         i = fetch_http(oiddata->claimed_id, buf, sizeof buf - 1, sizeof oiddata->claimed_id);
 222         CtdlLogPrintf(CTDL_DEBUG, "Normalized URL and Claimed ID is: %s\n", oiddata->claimed_id);
 223         buf[sizeof buf - 1] = 0;
 224         if (i > 0) {
 225                 char openid_delegate[1024];
 226
 227                 extract_link(oiddata->server, sizeof oiddata->server, "openid.server", buf);
 228                 extract_link(openid_delegate, sizeof openid_delegate, "openid.delegate", buf);
 229
 230                 if (IsEmptyStr(oiddata->server)) {
 231                         cprintf("%d There is no OpenID identity provider at this URL.\n", ERROR);
 232                         return;
 233                 }
 234
 235                 /* Empty delegate is legal; we just use the openid_url instead */
 236                 if (IsEmptyStr(openid_delegate)) {
 237                         safestrncpy(openid_delegate, oiddata->claimed_id, sizeof openid_delegate);
 238                 }
 239
 240                 /* Assemble a URL to which the user-agent will be redirected. */
 241                 char redirect_string[4096];
 242                 char escaped_identity[512];
 243                 char escaped_return_to[2048];
 244                 char escaped_trust_root[1024];
 245                 char escaped_sreg_optional[256];
 246
 247                 urlesc(escaped_identity, sizeof escaped_identity, openid_delegate);
 248                 urlesc(escaped_return_to, sizeof escaped_return_to, return_to);
 249                 urlesc(escaped_trust_root, sizeof escaped_trust_root, trust_root);
 250                 urlesc(escaped_sreg_optional, sizeof escaped_sreg_optional,
 251                         "nickname,email,fullname,postcode,country");
 252
 253                 snprintf(redirect_string, sizeof redirect_string,
 254                         "%s"
 255                         "?openid.mode=checkid_setup"
 256                         "&openid.identity=%s"
 257                         "&openid.return_to=%s"
 258                         "&openid.trust_root=%s"
 259                         "&openid.sreg.optional=%s"
 260                         ,
 261                         oiddata->server,
 262                         escaped_identity,
 263                         escaped_return_to,
 264                         escaped_trust_root,
 265                         escaped_sreg_optional
 266                 );
 267                 cprintf("%d %s\n", CIT_OK, redirect_string);
 268                 return;
 269         }
 270
 271         cprintf("%d Unable to fetch OpenID URL\n", ERROR);
 272 }
 273
 274
 275
 276 /*
 277  * Callback function to free a pointer (used below in the hash list)
 278  */
 279 void free_oid_key(void *ptr) {
 280         free(ptr);
 281 }
 282
 283
 284 /*
 285  * Finalize an OpenID authentication
 286  */
 287 void cmd_oidf(char *argbuf) {
 288         char buf[2048];
 289         char thiskey[1024];
 290         char thisdata[1024];
 291         HashList *keys = NULL;
 292         HashPos *HashPos;
 293         struct ctdl_openid *oiddata = (struct ctdl_openid *) CC->openid_data;
 294
 295         keys = NewHash(1, NULL);
 296         if (!keys) {
 297                 cprintf("%d NewHash() failed\n", ERROR + INTERNAL_ERROR);
 298                 return;
 299         }
 300
 301         cprintf("%d Transmit OpenID data now\n", START_CHAT_MODE);
 302
 303         while (client_getln(buf, sizeof buf), strcmp(buf, "000")) {
 304                 extract_token(thiskey, buf, 0, '|', sizeof thiskey);
 305                 extract_token(thisdata, buf, 1, '|', sizeof thisdata);
 306                 CtdlLogPrintf(CTDL_DEBUG, "%s: [%d] %s\n", thiskey, strlen(thisdata), thisdata);
 307                 Put(keys, thiskey, strlen(thiskey), strdup(thisdata), free_oid_key);
 308         }
 309
 310
 311         /* Now that we have all of the parameters, we have to validate the signature against the server */
 312         CtdlLogPrintf(CTDL_DEBUG, "About to validate the signature...\n");
 313
 314         CURL *curl;
 315         CURLcode res;
 316         struct curl_httppost *formpost = NULL;
 317         struct curl_httppost *lastptr = NULL;
 318         char errmsg[1024] = "";
 319         char *o_assoc_handle = NULL;
 320         char *o_sig = NULL;
 321         char *o_signed = NULL;
 322         int num_signed_values;
 323         int i;
 324         char k_keyname[128];
 325         char k_o_keyname[128];
 326         char *k_value = NULL;
 327
 328         curl_formadd(&formpost, &lastptr,
 329                 CURLFORM_COPYNAME,      "openid.mode",
 330                 CURLFORM_COPYCONTENTS,  "check_authentication",
 331                 CURLFORM_END);
 332
 333         if (GetHash(keys, "assoc_handle", 12, (void *) &o_assoc_handle)) {
 334                 curl_formadd(&formpost, &lastptr,
 335                         CURLFORM_COPYNAME,      "openid.assoc_handle",
 336                         CURLFORM_COPYCONTENTS,  o_assoc_handle,
 337                         CURLFORM_END);
 338         }
 339
 340         if (GetHash(keys, "sig", 3, (void *) &o_sig)) {
 341                 curl_formadd(&formpost, &lastptr,
 342                         CURLFORM_COPYNAME,      "openid.sig",
 343                         CURLFORM_COPYCONTENTS,  o_sig,
 344                         CURLFORM_END);
 345         }
 346
 347         if (GetHash(keys, "signed", 6, (void *) &o_signed)) {
 348                 curl_formadd(&formpost, &lastptr,
 349                         CURLFORM_COPYNAME,      "openid.signed",
 350                         CURLFORM_COPYCONTENTS,  o_signed,
 351                         CURLFORM_END);
 352
 353                 num_signed_values = num_tokens(o_signed, ',');
 354                 for (i=0; i<num_signed_values; ++i) {
 355                         extract_token(k_keyname, o_signed, i, ',', sizeof k_keyname);
 356                         if (GetHash(keys, k_keyname, strlen(k_keyname), (void *) &k_value)) {
 357                                 snprintf(k_o_keyname, sizeof k_o_keyname, "openid.%s", k_keyname);
 358                                 curl_formadd(&formpost, &lastptr,
 359                                         CURLFORM_COPYNAME,      k_o_keyname,
 360                                         CURLFORM_COPYCONTENTS,  k_value,
 361                                         CURLFORM_END);
 362                         }
 363                 }
 364         }
 365
 366         curl = curl_easy_init();
 367         curl_easy_setopt(curl, CURLOPT_URL, oiddata->server);
 368         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0);
 369         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0);
 370         // curl_easy_setopt(curl, CURLOPT_WRITEDATA, &fh);
 371         // curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fh_callback);
 372         curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost);
 373         curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, errmsg);
 374         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
 375         res = curl_easy_perform(curl);
 376         if (res) {
 377                 CtdlLogPrintf(CTDL_DEBUG, "cmd_oidf() libcurl error %d: %s\n", res, errmsg);
 378         }
 379         curl_easy_cleanup(curl);
 380         curl_formfree(formpost);
 381
 382         /* FIXME do something with the results */
 383
 384         /* Respond to the client */
 385         cprintf("message|FIXME finish this\n");
 386         cprintf("000\n");
 387
 388         /* Free the hash list */
 389         long len;
 390         void *Value;
 391         char *Key;
 392
 393         HashPos = GetNewHashPos();
 394         while (GetNextHashPos(keys, HashPos, &len, &Key, &Value)!=0)
 395         {
 396                 free(Value);
 397         }
 398         DeleteHashPos(&HashPos);
 399 }
 400
 401
 402 // mode = [6]  id_res
 403 // identity = [50]  http://uncensored.citadel.org/~ajc/MyID.config.php
 404 // assoc_handle = [26]  6ekac3ju181tgepk7v4h9r7ui7
 405 // return_to = [42]  http://jemcaterers.net/finish_openid_login
 406 // sreg.nickname = [17]  IGnatius T Foobar
 407 // sreg.email = [26]  ajc@uncensored.citadel.org
 408 // sreg.fullname = [10]  Art Cancro
 409 // sreg.postcode = [5]  10549
 410 // sreg.country = [2]  US
 411 // signed = [102]  mode,identity,assoc_handle,return_to,sreg.nickname,sreg.email,sreg.fullname,sreg.postcode,sreg.country
 412 // sig = [28]  vixxxU4MAqWfxxxxCfrHv3TxxxhEw=
 413
 414
 415 /*
 416  * This cleanup function blows away the temporary memory used by this module.
 417  */
 418 void openid_cleanup_function(void) {
 419
 420         if (CC->openid_data != NULL) {
 421                 free(CC->openid_data);
 422         }
 423 }
 424
 425
 426
 427 CTDL_MODULE_INIT(openid_rp)
 428 {
 429         if (!threading)
 430         {
 431                 curl_global_init(CURL_GLOBAL_ALL);
 432                 CtdlRegisterProtoHook(cmd_oids, "OIDS", "Setup OpenID authentication");
 433                 CtdlRegisterProtoHook(cmd_oidf, "OIDF", "Finalize OpenID authentication");
 434                 CtdlRegisterSessionHook(openid_cleanup_function, EVT_STOP);
 435         }
 436
 437         /* return our Subversion id for the Log */
 438         return "$Id$";
 439 }