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  * Locate a <link> tag and, given its 'rel=' parameter, return its 'href' parameter
  44  */
  45 void extract_link(char *target_buf, int target_size, char *rel, char *source_buf)
  46 {
  47         char *ptr = source_buf;
  48
  49         if (!target_buf) return;
  50         if (!rel) return;
  51         if (!source_buf) return;
  52
  53         target_buf[0] = 0;
  54
  55         while (ptr = bmstrcasestr(ptr, "<link"), ptr != NULL) {
  56
  57                 char work_buffer[2048];
  58                 char *link_tag_start = NULL;
  59                 char *link_tag_end = NULL;
  60
  61                 char rel_tag[2048];
  62                 char href_tag[2048];
  63
  64                 link_tag_start = ptr;
  65                 link_tag_end = strchr(ptr, '>');
  66                 rel_tag[0] = 0;
  67                 href_tag[0] = 0;
  68
  69                 if ((link_tag_end) && (link_tag_end > link_tag_start)) {
  70                         int len;
  71                         len = link_tag_end - link_tag_start;
  72                         if (len > sizeof work_buffer) len = sizeof work_buffer;
  73                         memcpy(work_buffer, link_tag_start, len);
  74
  75                         char *rel_start = NULL;
  76                         char *rel_end = NULL;
  77                         rel_start = bmstrcasestr(work_buffer, "rel=");
  78                         if (rel_start) {
  79                                 rel_start = strchr(rel_start, '\"');
  80                                 if (rel_start) {
  81                                         ++rel_start;
  82                                         rel_end = strchr(rel_start, '\"');
  83                                         if ((rel_end) && (rel_end > rel_start)) {
  84                                                 safestrncpy(rel_tag, rel_start, rel_end - rel_start + 1);
  85                                         }
  86                                 }
  87                         }
  88
  89                         char *href_start = NULL;
  90                         char *href_end = NULL;
  91                         href_start = bmstrcasestr(work_buffer, "href=");
  92                         if (href_start) {
  93                                 href_start = strchr(href_start, '\"');
  94                                 if (href_start) {
  95                                         ++href_start;
  96                                         href_end = strchr(href_start, '\"');
  97                                         if ((href_end) && (href_end > href_start)) {
  98                                                 safestrncpy(href_tag, href_start, href_end - href_start + 1);
  99                                         }
 100                                 }
 101                         }
 102
 103                         if (!strcasecmp(rel, rel_tag)) {
 104                                 safestrncpy(target_buf, href_tag, target_size);
 105                                 return;
 106                         }
 107
 108                 }
 109
 110         ++ptr;
 111         }
 112
 113
 114 }
 115
 116
 117
 118 struct fh_data {
 119         char *buf;
 120         int total_bytes_received;
 121         int maxbytes;
 122 };
 123
 124
 125 size_t fh_callback(void *ptr, size_t size, size_t nmemb, void *stream)
 126 {
 127         struct fh_data *fh = (struct fh_data *) stream;
 128         int got_bytes = (size * nmemb);
 129
 130         if (fh->total_bytes_received + got_bytes > fh->maxbytes) {
 131                 got_bytes = fh->maxbytes - fh->total_bytes_received;
 132         }
 133         if (got_bytes > 0) {
 134                 memcpy(&fh->buf[fh->total_bytes_received], ptr, got_bytes);
 135                 fh->total_bytes_received += got_bytes;
 136         }
 137
 138         return (size * nmemb);  /* always succeed; libcurl doesn't need to know if we truncated it */
 139 }
 140
 141
 142
 143 /*
 144  * Begin an HTTP fetch (returns number of bytes actually fetched, or -1 for error) using libcurl.
 145  *
 146  * If 'normalize_len' is nonzero, the caller is specifying the buffer size of 'url', and is
 147  * requesting that the effective (normalized) URL be copied back to it.
 148  */
 149 int fetch_http(char *url, char *target_buf, int maxbytes, int normalize_len)
 150 {
 151         CURL *curl;
 152         CURLcode res;
 153         char errmsg[1024] = "";
 154         struct fh_data fh = {
 155                 target_buf,
 156                 0,
 157                 maxbytes
 158         };
 159         char *effective_url = NULL;
 160
 161         if (!url) return(-1);
 162         if (!target_buf) return(-1);
 163         memset(target_buf, 0, maxbytes);
 164
 165         curl = curl_easy_init();
 166         if (!curl) {
 167                 CtdlLogPrintf(CTDL_ALERT, "Unable to initialize libcurl.\n");
 168                 return(-1);
 169         }
 170
 171         curl_easy_setopt(curl, CURLOPT_URL, url);
 172         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0);
 173         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0);
 174         curl_easy_setopt(curl, CURLOPT_WRITEDATA, &fh);
 175         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fh_callback);
 176         curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, errmsg);
 177         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
 178         curl_easy_setopt(curl, CURLOPT_USERAGENT, CITADEL);
 179         if (!IsEmptyStr(config.c_ip_addr)) {
 180                 curl_easy_setopt(curl, CURLOPT_INTERFACE, config.c_ip_addr);
 181         }
 182         res = curl_easy_perform(curl);
 183         if (res) {
 184                 CtdlLogPrintf(CTDL_DEBUG, "fetch_http() libcurl error %d: %s\n", res, errmsg);
 185         }
 186         if (normalize_len > 0) {
 187                 curl_easy_getinfo(curl, CURLINFO_EFFECTIVE_URL, &effective_url);
 188                 safestrncpy(url, effective_url, normalize_len);
 189         }
 190         curl_easy_cleanup(curl);
 191         return fh.total_bytes_received;
 192 }
 193
 194
 195 /*
 196  * Setup an OpenID authentication
 197  */
 198 void cmd_oids(char *argbuf) {
 199         char return_to[1024];
 200         char trust_root[1024];
 201         int i;
 202         char buf[SIZ];
 203         struct CitContext *CCC = CC;    /* CachedCitContext - performance boost */
 204         struct ctdl_openid *oiddata;
 205
 206         if (CCC->logged_in) {
 207                 cprintf("%d Already logged in.\n", ERROR + ALREADY_LOGGED_IN);
 208                 return;
 209         }
 210
 211         if (CCC->openid_data != NULL) {
 212                 free(CCC->openid_data);
 213         }
 214         oiddata = malloc(sizeof(struct ctdl_openid));
 215         if (oiddata == NULL) {
 216                 cprintf("%d malloc failed\n", ERROR + INTERNAL_ERROR);
 217                 return;
 218         }
 219         memset(oiddata, 0, sizeof(struct ctdl_openid));
 220         CCC->openid_data = (void *) oiddata;
 221
 222         extract_token(oiddata->claimed_id, argbuf, 0, '|', sizeof oiddata->claimed_id);
 223         extract_token(return_to, argbuf, 1, '|', sizeof return_to);
 224         extract_token(trust_root, argbuf, 2, '|', sizeof trust_root);
 225
 226         i = fetch_http(oiddata->claimed_id, buf, sizeof buf - 1, sizeof oiddata->claimed_id);
 227         CtdlLogPrintf(CTDL_DEBUG, "Normalized URL and Claimed ID is: %s\n", oiddata->claimed_id);
 228         buf[sizeof buf - 1] = 0;
 229         if (i > 0) {
 230                 char openid_delegate[1024];
 231
 232                 extract_link(oiddata->server, sizeof oiddata->server, "openid.server", buf);
 233                 extract_link(openid_delegate, sizeof openid_delegate, "openid.delegate", buf);
 234
 235                 if (IsEmptyStr(oiddata->server)) {
 236                         cprintf("%d There is no OpenID identity provider at this URL.\n", ERROR);
 237                         return;
 238                 }
 239
 240                 /* Empty delegate is legal; we just use the openid_url instead */
 241                 if (IsEmptyStr(openid_delegate)) {
 242                         safestrncpy(openid_delegate, oiddata->claimed_id, sizeof openid_delegate);
 243                 }
 244
 245                 /* Assemble a URL to which the user-agent will be redirected. */
 246                 char redirect_string[4096];
 247                 char escaped_identity[512];
 248                 char escaped_return_to[2048];
 249                 char escaped_trust_root[1024];
 250                 char escaped_sreg_optional[256];
 251
 252                 urlesc(escaped_identity, sizeof escaped_identity, openid_delegate);
 253                 urlesc(escaped_return_to, sizeof escaped_return_to, return_to);
 254                 urlesc(escaped_trust_root, sizeof escaped_trust_root, trust_root);
 255                 urlesc(escaped_sreg_optional, sizeof escaped_sreg_optional,
 256                         "nickname,email,fullname,postcode,country");
 257
 258                 snprintf(redirect_string, sizeof redirect_string,
 259                         "%s"
 260                         "?openid.mode=checkid_setup"
 261                         "&openid.identity=%s"
 262                         "&openid.return_to=%s"
 263                         "&openid.trust_root=%s"
 264                         "&openid.sreg.optional=%s"
 265                         ,
 266                         oiddata->server,
 267                         escaped_identity,
 268                         escaped_return_to,
 269                         escaped_trust_root,
 270                         escaped_sreg_optional
 271                 );
 272                 cprintf("%d %s\n", CIT_OK, redirect_string);
 273                 return;
 274         }
 275
 276         cprintf("%d Unable to fetch OpenID URL\n", ERROR);
 277 }
 278
 279
 280
 281 /*
 282  * Callback function to free a pointer (used below in the hash list)
 283  */
 284 void free_oid_key(void *ptr) {
 285         free(ptr);
 286 }
 287
 288
 289 /*
 290  * Finalize an OpenID authentication
 291  */
 292 void cmd_oidf(char *argbuf) {
 293         char buf[2048];
 294         char thiskey[1024];
 295         char thisdata[1024];
 296         HashList *keys = NULL;
 297         HashPos *HashPos;
 298         struct ctdl_openid *oiddata = (struct ctdl_openid *) CC->openid_data;
 299
 300         keys = NewHash(1, NULL);
 301         if (!keys) {
 302                 cprintf("%d NewHash() failed\n", ERROR + INTERNAL_ERROR);
 303                 return;
 304         }
 305
 306         cprintf("%d Transmit OpenID data now\n", START_CHAT_MODE);
 307
 308         while (client_getln(buf, sizeof buf), strcmp(buf, "000")) {
 309                 extract_token(thiskey, buf, 0, '|', sizeof thiskey);
 310                 extract_token(thisdata, buf, 1, '|', sizeof thisdata);
 311                 CtdlLogPrintf(CTDL_DEBUG, "%s: [%d] %s\n", thiskey, strlen(thisdata), thisdata);
 312                 Put(keys, thiskey, strlen(thiskey), strdup(thisdata), free_oid_key);
 313         }
 314
 315
 316         /* Now that we have all of the parameters, we have to validate the signature against the server */
 317         CtdlLogPrintf(CTDL_DEBUG, "About to validate the signature...\n");
 318
 319         CURL *curl;
 320         CURLcode res;
 321         struct curl_httppost *formpost = NULL;
 322         struct curl_httppost *lastptr = NULL;
 323         char errmsg[1024] = "";
 324         char *o_assoc_handle = NULL;
 325         char *o_sig = NULL;
 326         char *o_signed = NULL;
 327         int num_signed_values;
 328         int i;
 329         char k_keyname[128];
 330         char k_o_keyname[128];
 331         char *k_value = NULL;
 332
 333         char valbuf[1024];
 334         struct fh_data fh = {
 335                 valbuf,
 336                 0,
 337                 sizeof valbuf
 338         };
 339
 340         curl_formadd(&formpost, &lastptr,
 341                 CURLFORM_COPYNAME,      "openid.mode",
 342                 CURLFORM_COPYCONTENTS,  "check_authentication",
 343                 CURLFORM_END);
 344         CtdlLogPrintf(CTDL_DEBUG, "%25s : %s\n", "openid.mode", "check_authentication");
 345
 346         if (GetHash(keys, "assoc_handle", 12, (void *) &o_assoc_handle)) {
 347                 curl_formadd(&formpost, &lastptr,
 348                         CURLFORM_COPYNAME,      "openid.assoc_handle",
 349                         CURLFORM_COPYCONTENTS,  o_assoc_handle,
 350                         CURLFORM_END);
 351                 CtdlLogPrintf(CTDL_DEBUG, "%25s : %s\n", "openid.assoc_handle", o_assoc_handle);
 352         }
 353
 354         if (GetHash(keys, "sig", 3, (void *) &o_sig)) {
 355                 curl_formadd(&formpost, &lastptr,
 356                         CURLFORM_COPYNAME,      "openid.sig",
 357                         CURLFORM_COPYCONTENTS,  o_sig,
 358                         CURLFORM_END);
 359                         CtdlLogPrintf(CTDL_DEBUG, "%25s : %s\n", "openid.sig", o_sig);
 360         }
 361
 362         if (GetHash(keys, "signed", 6, (void *) &o_signed)) {
 363                 curl_formadd(&formpost, &lastptr,
 364                         CURLFORM_COPYNAME,      "openid.signed",
 365                         CURLFORM_COPYCONTENTS,  o_signed,
 366                         CURLFORM_END);
 367                 CtdlLogPrintf(CTDL_DEBUG, "%25s : %s\n", "openid.signed", o_signed);
 368
 369                 num_signed_values = num_tokens(o_signed, ',');
 370                 for (i=0; i<num_signed_values; ++i) {
 371                         extract_token(k_keyname, o_signed, i, ',', sizeof k_keyname);
 372                         if (strcasecmp(k_keyname, "mode")) {    // work around phpMyID bug
 373                                 if (GetHash(keys, k_keyname, strlen(k_keyname), (void *) &k_value)) {
 374                                         snprintf(k_o_keyname, sizeof k_o_keyname, "openid.%s", k_keyname);
 375                                         curl_formadd(&formpost, &lastptr,
 376                                                 CURLFORM_COPYNAME,      k_o_keyname,
 377                                                 CURLFORM_COPYCONTENTS,  k_value,
 378                                                 CURLFORM_END);
 379                                         CtdlLogPrintf(CTDL_DEBUG, "%25s : %s\n", k_o_keyname, k_value);
 380                                 }
 381                                 else {
 382                                         CtdlLogPrintf(CTDL_INFO, "OpenID: signed field '%s' is missing\n",
 383                                                 k_keyname);
 384                                 }
 385                         }
 386                 }
 387         }
 388
 389         curl = curl_easy_init();
 390         curl_easy_setopt(curl, CURLOPT_URL, oiddata->server);
 391         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0);
 392         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0);
 393         curl_easy_setopt(curl, CURLOPT_WRITEDATA, &fh);
 394         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fh_callback);
 395         curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost);
 396         curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, errmsg);
 397         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
 398         curl_easy_setopt(curl, CURLOPT_USERAGENT, CITADEL);
 399         if (!IsEmptyStr(config.c_ip_addr)) {
 400                 curl_easy_setopt(curl, CURLOPT_INTERFACE, config.c_ip_addr);
 401         }
 402
 403         res = curl_easy_perform(curl);
 404         if (res) {
 405                 CtdlLogPrintf(CTDL_DEBUG, "cmd_oidf() libcurl error %d: %s\n", res, errmsg);
 406         }
 407         curl_easy_cleanup(curl);
 408         curl_formfree(formpost);
 409
 410         valbuf[fh.total_bytes_received] = 0;
 411         if (bmstrcasestr(valbuf, "is_valid:true")) {
 412                 CtdlLogPrintf(CTDL_DEBUG, "\e[32mVALIDATION SUCCEEDED!!  WOWOWOWWW!!\e[0m\n", valbuf);
 413         }
 414         else {
 415                 CtdlLogPrintf(CTDL_DEBUG, "\e[31mVALIDATION FAILED.  DIACF.\e[0m\n", valbuf);
 416         }
 417
 418         /* FIXME do something with the results */
 419
 420         /* Respond to the client */
 421         cprintf("message|FIXME finish this\n");
 422         cprintf("000\n");
 423
 424         /* Free the hash list */
 425         long len;
 426         void *Value;
 427         char *Key;
 428
 429         HashPos = GetNewHashPos();
 430         while (GetNextHashPos(keys, HashPos, &len, &Key, &Value)!=0)
 431         {
 432                 free(Value);
 433         }
 434         DeleteHashPos(&HashPos);
 435 }
 436
 437
 438 // mode = [6]  id_res
 439 // identity = [50]  http://uncensored.citadel.org/~ajc/MyID.config.php
 440 // assoc_handle = [26]  6ekac3ju181tgepk7v4h9r7ui7
 441 // return_to = [42]  http://jemcaterers.net/finish_openid_login
 442 // sreg.nickname = [17]  IGnatius T Foobar
 443 // sreg.email = [26]  ajc@uncensored.citadel.org
 444 // sreg.fullname = [10]  Art Cancro
 445 // sreg.postcode = [5]  10549
 446 // sreg.country = [2]  US
 447 // signed = [102]  mode,identity,assoc_handle,return_to,sreg.nickname,sreg.email,sreg.fullname,sreg.postcode,sreg.country
 448 // sig = [28]  vixxxU4MAqWfxxxxCfrHv3TxxxhEw=
 449
 450
 451 /*
 452  * This cleanup function blows away the temporary memory used by this module.
 453  */
 454 void openid_cleanup_function(void) {
 455
 456         if (CC->openid_data != NULL) {
 457                 free(CC->openid_data);
 458         }
 459 }
 460
 461
 462
 463 CTDL_MODULE_INIT(openid_rp)
 464 {
 465         if (!threading)
 466         {
 467                 curl_global_init(CURL_GLOBAL_ALL);
 468                 CtdlRegisterProtoHook(cmd_oids, "OIDS", "Setup OpenID authentication");
 469                 CtdlRegisterProtoHook(cmd_oidf, "OIDF", "Finalize OpenID authentication");
 470                 CtdlRegisterSessionHook(openid_cleanup_function, EVT_STOP);
 471         }
 472
 473         /* return our Subversion id for the Log */
 474         return "$Id$";
 475 }