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 got_bytes;
 138 }
 139
 140
 141
 142 /*
 143  * Begin an HTTP fetch (returns number of bytes actually fetched, or -1 for error)
 144  * We first try 'curl' or 'wget' because they have more robust HTTP handling, and also
 145  * support HTTPS.  If neither one works, we fall back to a built in mini HTTP client.
 146  */
 147 int fetch_http(char *url, char *target_buf, int maxbytes)
 148 {
 149         CURL *curl;
 150         CURLcode res;
 151         char errmsg[1024] = "";
 152         struct fh_data fh = {
 153                 target_buf,
 154                 0,
 155                 maxbytes
 156         };
 157
 158         if (!url) return(-1);
 159         if (!target_buf) return(-1);
 160         memset(target_buf, 0, maxbytes);
 161
 162         curl = curl_easy_init();
 163         if (!curl) {
 164                 CtdlLogPrintf(CTDL_ALERT, "Unable to initialize libcurl.\n");
 165                 return(-1);
 166         }
 167
 168         curl_easy_setopt(curl, CURLOPT_URL, url);
 169         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0);
 170         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0);
 171         curl_easy_setopt(curl, CURLOPT_WRITEDATA, &fh);
 172         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fh_callback);
 173         curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, errmsg);
 174         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
 175         res = curl_easy_perform(curl);
 176         if (res) {
 177                 CtdlLogPrintf(CTDL_DEBUG, "fetch_http() libcurl error %d: %s\n", res, errmsg);
 178         }
 179         curl_easy_cleanup(curl);
 180         return fh.total_bytes_received;
 181 }
 182
 183
 184 /*
 185  * Setup an OpenID authentication
 186  */
 187 void cmd_oids(char *argbuf) {
 188         char return_to[1024];
 189         char trust_root[1024];
 190         int i;
 191         char buf[SIZ];
 192         struct CitContext *CCC = CC;    /* CachedCitContext - performance boost */
 193         struct ctdl_openid *oiddata;
 194
 195         if (CCC->logged_in) {
 196                 cprintf("%d Already logged in.\n", ERROR + ALREADY_LOGGED_IN);
 197                 return;
 198         }
 199
 200         if (CCC->openid_data != NULL) {
 201                 free(CCC->openid_data);
 202         }
 203         oiddata = malloc(sizeof(struct ctdl_openid));
 204         if (oiddata == NULL) {
 205                 cprintf("%d malloc failed\n", ERROR + INTERNAL_ERROR);
 206                 return;
 207         }
 208         memset(oiddata, 0, sizeof(struct ctdl_openid));
 209         CCC->openid_data = (void *) oiddata;
 210
 211         extract_token(oiddata->claimed_id, argbuf, 0, '|', sizeof oiddata->claimed_id);
 212         extract_token(return_to, argbuf, 1, '|', sizeof return_to);
 213         extract_token(trust_root, argbuf, 2, '|', sizeof trust_root);
 214
 215         CtdlLogPrintf(CTDL_DEBUG, "Asking %s for server and delegate\n", oiddata->claimed_id);
 216         i = fetch_http(oiddata->claimed_id, buf, sizeof buf - 1);
 217         buf[sizeof buf - 1] = 0;
 218         if (i > 0) {
 219                 char openid_delegate[1024];
 220
 221                 extract_link(oiddata->server, sizeof oiddata->server, "openid.server", buf);
 222                 extract_link(openid_delegate, sizeof openid_delegate, "openid.delegate", buf);
 223
 224                 if (IsEmptyStr(oiddata->server)) {
 225                         cprintf("%d There is no OpenID identity provider at this URL.\n", ERROR);
 226                         return;
 227                 }
 228
 229                 /* Empty delegate is legal; we just use the openid_url instead */
 230                 if (IsEmptyStr(openid_delegate)) {
 231                         safestrncpy(openid_delegate, oiddata->claimed_id, sizeof openid_delegate);
 232                 }
 233
 234                 /* Assemble a URL to which the user-agent will be redirected. */
 235                 char redirect_string[4096];
 236                 char escaped_identity[512];
 237                 char escaped_return_to[2048];
 238                 char escaped_trust_root[1024];
 239                 char escaped_sreg_optional[256];
 240
 241                 urlesc(escaped_identity, sizeof escaped_identity, openid_delegate);
 242                 urlesc(escaped_return_to, sizeof escaped_return_to, return_to);
 243                 urlesc(escaped_trust_root, sizeof escaped_trust_root, trust_root);
 244                 urlesc(escaped_sreg_optional, sizeof escaped_sreg_optional,
 245                         "nickname,email,fullname,postcode,country");
 246
 247                 snprintf(redirect_string, sizeof redirect_string,
 248                         "%s"
 249                         "?openid.mode=checkid_setup"
 250                         "&openid.identity=%s"
 251                         "&openid.return_to=%s"
 252                         "&openid.trust_root=%s"
 253                         "&openid.sreg.optional=%s"
 254                         ,
 255                         oiddata->server,
 256                         escaped_identity,
 257                         escaped_return_to,
 258                         escaped_trust_root,
 259                         escaped_sreg_optional
 260                 );
 261                 cprintf("%d %s\n", CIT_OK, redirect_string);
 262                 return;
 263         }
 264
 265         cprintf("%d Unable to fetch OpenID URL\n", ERROR);
 266 }
 267
 268
 269
 270 /*
 271  * Callback function to free a pointer (used below in the hash list)
 272  */
 273 void free_oid_key(void *ptr) {
 274         free(ptr);
 275 }
 276
 277
 278 /*
 279  * Finalize an OpenID authentication
 280  */
 281 void cmd_oidf(char *argbuf) {
 282         char buf[2048];
 283         char thiskey[1024];
 284         char thisdata[1024];
 285         HashList *keys = NULL;
 286         HashPos *HashPos;
 287
 288         keys = NewHash(1, NULL);
 289         if (!keys) {
 290                 cprintf("%d NewHash() failed\n", ERROR + INTERNAL_ERROR);
 291                 return;
 292         }
 293
 294         cprintf("%d Transmit OpenID data now\n", START_CHAT_MODE);
 295
 296         while (client_getln(buf, sizeof buf), strcmp(buf, "000")) {
 297                 extract_token(thiskey, buf, 0, '|', sizeof thiskey);
 298                 extract_token(thisdata, buf, 1, '|', sizeof thisdata);
 299                 CtdlLogPrintf(CTDL_DEBUG, "%s: [%d] %s\n", thiskey, strlen(thisdata), thisdata);
 300                 Put(keys, thiskey, strlen(thiskey), strdup(thisdata), free_oid_key);
 301         }
 302
 303
 304         /* Now that we have all of the parameters, we have to validate the signature against the server */
 305
 306         CURL *curl;
 307         CURLcode res;
 308         struct curl_httppost *formpost = NULL;
 309         struct curl_httppost *lastptr = NULL;
 310         char errmsg[1024] = "";
 311
 312         curl_formadd(&formpost, &lastptr,
 313                 CURLFORM_COPYNAME,      "openid.mode",
 314                 CURLFORM_COPYCONTENTS,  "check_authentication",
 315                 CURLFORM_END);
 316
 317         curl = curl_easy_init();
 318         // curl_easy_setopt(curl, CURLOPT_URL, FIXME );         /* FIXME need to bring this over */
 319         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0);
 320         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0);
 321         // curl_easy_setopt(curl, CURLOPT_WRITEDATA, &fh);
 322         // curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fh_callback);
 323         curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost);
 324         curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, errmsg);
 325         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
 326         res = curl_easy_perform(curl);
 327         if (res) {
 328                 CtdlLogPrintf(CTDL_DEBUG, "cmd_oidf() libcurl error %d: %s\n", res, errmsg);
 329         }
 330         curl_easy_cleanup(curl);
 331         curl_formfree(formpost);
 332
 333         /* FIXME do something with the results */
 334
 335         /* Respond to the client */
 336         cprintf("message|FIXME finish this\n");
 337         cprintf("000\n");
 338
 339         /* Free the hash list */
 340         long len;
 341         void *Value;
 342         char *Key;
 343
 344         HashPos = GetNewHashPos();
 345         while (GetNextHashPos(keys, HashPos, &len, &Key, &Value)!=0)
 346         {
 347                 free(Value);
 348         }
 349         DeleteHashPos(&HashPos);
 350 }
 351
 352
 353 // mode = [6]  id_res
 354 // identity = [50]  http://uncensored.citadel.org/~ajc/MyID.config.php
 355 // assoc_handle = [26]  6ekac3ju181tgepk7v4h9r7ui7
 356 // return_to = [42]  http://jemcaterers.net/finish_openid_login
 357 // sreg.nickname = [17]  IGnatius T Foobar
 358 // sreg.email = [26]  ajc@uncensored.citadel.org
 359 // sreg.fullname = [10]  Art Cancro
 360 // sreg.postcode = [5]  10549
 361 // sreg.country = [2]  US
 362 // signed = [102]  mode,identity,assoc_handle,return_to,sreg.nickname,sreg.email,sreg.fullname,sreg.postcode,sreg.country
 363 // sig = [28]  vixxxU4MAqWfxxxxCfrHv3TxxxhEw=
 364
 365
 366 /*
 367  * This cleanup function blows away the temporary memory used by this module.
 368  */
 369 void openid_cleanup_function(void) {
 370
 371         if (CC->openid_data != NULL) {
 372                 free(CC->openid_data);
 373         }
 374 }
 375
 376
 377
 378 CTDL_MODULE_INIT(openid_rp)
 379 {
 380         if (!threading)
 381         {
 382                 curl_global_init(CURL_GLOBAL_ALL);
 383                 CtdlRegisterProtoHook(cmd_oids, "OIDS", "Setup OpenID authentication");
 384                 CtdlRegisterProtoHook(cmd_oidf, "OIDF", "Finalize OpenID authentication");
 385                 CtdlRegisterSessionHook(openid_cleanup_function, EVT_STOP);
 386         }
 387
 388         /* return our Subversion id for the Log */
 389         return "$Id$";
 390 }