4 * OpenID 1.1 "relying party" implementation
16 #include <sys/types.h>
18 #if TIME_WITH_SYS_TIME
19 # include <sys/time.h>
23 # include <sys/time.h>
32 #include <curl/curl.h>
33 #include "ctdl_module.h"
36 struct associate_handle {
39 time_t expiration_time;
40 char assoc_handle[128];
44 HashList *HL = NULL; // hash table of assoc_handle
47 * Locate a <link> tag and, given its 'rel=' parameter, return its 'href' parameter
49 void extract_link(char *target_buf, int target_size, char *rel, char *source_buf)
51 char *ptr = source_buf;
53 if (!target_buf) return;
55 if (!source_buf) return;
59 while (ptr = bmstrcasestr(ptr, "<link"), ptr != NULL) {
61 char work_buffer[1024];
62 char *link_tag_start = NULL;
63 char *link_tag_end = NULL;
69 link_tag_end = strchr(ptr, '>');
73 if ((link_tag_end) && (link_tag_end > link_tag_start)) {
75 len = link_tag_end - link_tag_start;
76 if (len > sizeof work_buffer) len = sizeof work_buffer;
77 memcpy(work_buffer, link_tag_start, len);
79 char *rel_start = NULL;
81 rel_start = bmstrcasestr(work_buffer, "rel=");
83 rel_start = strchr(rel_start, '\"');
86 rel_end = strchr(rel_start, '\"');
87 if ((rel_end) && (rel_end > rel_start)) {
88 safestrncpy(rel_tag, rel_start, rel_end - rel_start + 1);
93 char *href_start = NULL;
94 char *href_end = NULL;
95 href_start = bmstrcasestr(work_buffer, "href=");
97 href_start = strchr(href_start, '\"');
100 href_end = strchr(href_start, '\"');
101 if ((href_end) && (href_end > href_start)) {
102 safestrncpy(href_tag, href_start, href_end - href_start + 1);
107 if (!strcasecmp(rel, rel_tag)) {
108 safestrncpy(target_buf, href_tag, target_size);
124 int total_bytes_received;
129 size_t fh_callback(void *ptr, size_t size, size_t nmemb, void *stream)
131 struct fh_data *fh = (struct fh_data *) stream;
132 int got_bytes = (size * nmemb);
134 if (fh->total_bytes_received + got_bytes > fh->maxbytes) {
135 got_bytes = fh->maxbytes - fh->total_bytes_received;
138 memcpy(&fh->buf[fh->total_bytes_received], ptr, got_bytes);
139 fh->total_bytes_received += got_bytes;
148 * Begin an HTTP fetch (returns number of bytes actually fetched, or -1 for error)
149 * We first try 'curl' or 'wget' because they have more robust HTTP handling, and also
150 * support HTTPS. If neither one works, we fall back to a built in mini HTTP client.
152 int fetch_http(char *url, char *target_buf, int maxbytes)
156 char errmsg[1024] = "";
157 struct fh_data fh = {
163 if (!url) return(-1);
164 if (!target_buf) return(-1);
165 memset(target_buf, 0, maxbytes);
167 curl = curl_easy_init();
169 CtdlLogPrintf(CTDL_ALERT, "Unable to initialize libcurl.\n");
173 curl_easy_setopt(curl, CURLOPT_URL, url);
174 curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0);
175 curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0);
176 curl_easy_setopt(curl, CURLOPT_WRITEDATA, &fh);
177 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fh_callback);
178 curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, errmsg);
179 curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
180 res = curl_easy_perform(curl);
181 curl_easy_cleanup(curl);
182 return fh.total_bytes_received;
186 #define ASSOCIATE_RESPONSE_SIZE 4096
189 * libcurl callback function for prepare_openid_associate_request()
191 size_t associate_callback(void *ptr, size_t size, size_t nmemb, void *stream)
193 char *response = (char *) stream;
194 int got_bytes = (size * nmemb);
195 int len = strlen(response);
197 if ((len + got_bytes + 1) < ASSOCIATE_RESPONSE_SIZE) {
198 memcpy(&response[len], ptr, got_bytes);
199 response[len+got_bytes] = 0;
207 * Helper function for process_associate_response()
208 * (Delete function for hash table)
210 void delete_assoc_handle(void *data) {
211 if (data) free(data);
216 * Process the response from an "associate" request
218 struct associate_handle *process_associate_response(char *claimed_id, char *associate_response)
220 struct associate_handle *h = NULL;
221 char *ptr = associate_response;
226 h = (struct associate_handle *) malloc(sizeof(struct associate_handle));
227 safestrncpy(h->claimed_id, claimed_id, sizeof h->claimed_id);
230 ptr = memreadline(ptr, thisline, sizeof thisline);
231 extract_token(thiskey, thisline, 0, ':', sizeof thiskey);
232 extract_token(thisdata, thisline, 1, ':', sizeof thisdata);
234 if (!strcasecmp(thiskey, "assoc_type")) {
235 safestrncpy(h->assoc_type, thisdata, sizeof h->assoc_type);
237 else if (!strcasecmp(thiskey, "expires_in")) {
238 h->expiration_time = time(NULL) + atol(thisdata);
240 else if (!strcasecmp(thiskey, "assoc_handle")) {
241 safestrncpy(h->assoc_handle, thisdata, sizeof h->assoc_handle);
243 else if (!strcasecmp(thiskey, "mac_key")) {
244 safestrncpy(h->mac_key, thisdata, sizeof h->mac_key);
249 /* Add this data structure into the hash table */
250 Put(HL, h->assoc_handle, strlen(h->assoc_handle), h, delete_assoc_handle);
252 /* FIXME periodically purge the hash table of expired handles */
260 * Establish a shared secret with an OpenID Identity Provider by sending
261 * an "associate" request.
263 struct associate_handle *prepare_openid_associate_request(
264 char *claimed_id, char *openid_server, char *openid_delegate)
268 struct curl_httppost *formpost=NULL;
269 struct curl_httppost *lastptr=NULL;
270 char associate_response[ASSOCIATE_RESPONSE_SIZE];
271 struct associate_handle *h = NULL;
273 memset(associate_response, 0, ASSOCIATE_RESPONSE_SIZE);
275 curl_formadd(&formpost,
277 CURLFORM_COPYNAME, "openid.mode",
278 CURLFORM_COPYCONTENTS, "associate",
282 curl_formadd(&formpost,
284 CURLFORM_COPYNAME, "openid.session_type",
285 CURLFORM_COPYCONTENTS, "",
289 curl = curl_easy_init();
291 curl_easy_setopt(curl, CURLOPT_URL, openid_server);
292 curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0);
293 curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0);
294 curl_easy_setopt(curl, CURLOPT_WRITEDATA, associate_response);
295 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, associate_callback);
296 curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
298 curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost);
299 res = curl_easy_perform(curl);
300 h = process_associate_response(claimed_id, associate_response);
301 curl_easy_cleanup(curl);
303 curl_formfree(formpost);
313 * Setup an OpenID authentication
315 void cmd_oids(char *argbuf) {
316 char openid_url[1024];
317 char return_to[1024];
318 char trust_root[1024];
321 struct associate_handle *h = NULL;
324 cprintf("%d Already logged in.\n", ERROR + ALREADY_LOGGED_IN);
328 extract_token(openid_url, argbuf, 0, '|', sizeof openid_url);
329 extract_token(return_to, argbuf, 1, '|', sizeof return_to);
330 extract_token(trust_root, argbuf, 2, '|', sizeof trust_root);
332 i = fetch_http(openid_url, buf, sizeof buf - 1);
333 buf[sizeof buf - 1] = 0;
335 char openid_server[1024];
336 char openid_delegate[1024];
338 extract_link(openid_server, sizeof openid_server, "openid.server", buf);
339 extract_link(openid_delegate, sizeof openid_delegate, "openid.delegate", buf);
341 if (IsEmptyStr(openid_server)) {
342 cprintf("%d There is no OpenID identity provider at this URL.\n", ERROR);
346 /* Empty delegate is legal; we just use the openid_url instead */
347 if (IsEmptyStr(openid_delegate)) {
348 safestrncpy(openid_delegate, openid_url, sizeof openid_delegate);
352 * Prepare an "associate" request. This contacts the IdP and fetches
353 * a data structure containing an assoc_handle plus a shared secret.
355 h = prepare_openid_associate_request(openid_url, openid_server, openid_delegate);
357 /* Assemble a URL to which the user-agent will be redirected. */
358 char redirect_string[4096];
359 char escaped_identity[1024];
360 char escaped_return_to[1024];
361 char escaped_trust_root[1024];
362 char escaped_sreg_optional[256];
363 char escaped_assoc_handle[256];
365 urlesc(escaped_identity, sizeof escaped_identity, openid_delegate);
366 urlesc(escaped_assoc_handle, sizeof escaped_assoc_handle, h->assoc_handle);
367 urlesc(escaped_return_to, sizeof escaped_return_to, return_to);
368 urlesc(escaped_trust_root, sizeof escaped_trust_root, trust_root);
369 urlesc(escaped_sreg_optional, sizeof escaped_sreg_optional,
370 "nickname,email,fullname,postcode,country");
372 snprintf(redirect_string, sizeof redirect_string,
374 "?openid.mode=checkid_setup"
375 "&openid.identity=%s"
376 "&openid.assoc_handle=%s"
377 "&openid.return_to=%s"
378 "&openid.trust_root=%s"
379 "&openid.sreg.optional=%s"
383 escaped_assoc_handle,
386 escaped_sreg_optional
388 CtdlLogPrintf(CTDL_DEBUG, "Telling client about assoc_handle <%s>\n", h->assoc_handle);
389 cprintf("%d %s\n", CIT_OK, redirect_string);
393 cprintf("%d Unable to fetch OpenID URL\n", ERROR);
399 * Finalize an OpenID authentication
401 void cmd_oidf(char *argbuf) {
402 char assoc_handle[256];
403 struct associate_handle *h = NULL;
405 extract_token(assoc_handle, argbuf, 0, '|', sizeof assoc_handle);
407 if (GetHash(HL, assoc_handle, strlen(assoc_handle), (void *)&h)) {
408 cprintf("%d handle %s is good\n", CIT_OK, assoc_handle);
410 // FIXME now do something with it
414 cprintf("%d handle %s not found\n", ERROR, assoc_handle);
421 CTDL_MODULE_INIT(openid_rp)
425 curl_global_init(CURL_GLOBAL_ALL);
426 HL = NewHash(1, NULL);
427 CtdlRegisterProtoHook(cmd_oids, "OIDS", "Setup OpenID authentication");
428 CtdlRegisterProtoHook(cmd_oidf, "OIDF", "Finalize OpenID authentication");
431 /* return our Subversion id for the Log */