+
+ else if (!strcasecmp(supplied_el, "service")) {
+ xrds->current_service_priority = 0;
+ xrds->current_service_is_oid2auth = 0;
+ for (i=0; attr[i] != NULL; i+=2) {
+ if (!strcasecmp(attr[i], "priority")) {
+ xrds->current_service_priority = atoi(attr[i+1]);
+ }
+ }
+ }
+
+ FlushStrBuf(xrds->CharData);
+}
+
+
+void xrds_xml_end(void *data, const char *supplied_el) {
+ struct xrds *xrds = (struct xrds *) data;
+
+ --xrds->nesting_level;
+
+ if (!strcasecmp(supplied_el, "XRD")) {
+ --xrds->in_xrd;
+ }
+
+ else if (!strcasecmp(supplied_el, "type")) {
+ if ( (xrds->in_xrd)
+ && (!strcasecmp(ChrPtr(xrds->CharData), "http://specs.openid.net/auth/2.0/server"))
+ ) {
+ xrds->current_service_is_oid2auth = 1;
+ }
+ if ( (xrds->in_xrd)
+ && (!strcasecmp(ChrPtr(xrds->CharData), "http://specs.openid.net/auth/2.0/signon"))
+ ) {
+ xrds->current_service_is_oid2auth = 1;
+ /* FIXME in this case, the Claimed ID should be considered immutable */
+ }
+ }
+
+ else if (!strcasecmp(supplied_el, "uri")) {
+ if (xrds->in_xrd) {
+ FlushStrBuf(xrds->current_service_uri);
+ StrBufAppendBuf(xrds->current_service_uri, xrds->CharData, 0);
+ }
+ }
+
+ else if (!strcasecmp(supplied_el, "service")) {
+ if ( (xrds->in_xrd)
+ && (xrds->current_service_priority < xrds->selected_service_priority)
+ && (xrds->current_service_is_oid2auth)
+ ) {
+ xrds->selected_service_priority = xrds->current_service_priority;
+ FlushStrBuf(xrds->selected_service_uri);
+ StrBufAppendBuf(xrds->selected_service_uri, xrds->current_service_uri, 0);
+ }
+
+ }
+
+ FlushStrBuf(xrds->CharData);
+}
+
+
+void xrds_xml_chardata(void *data, const XML_Char *s, int len) {
+ struct xrds *xrds = (struct xrds *) data;
+
+ StrBufAppendBufPlain (xrds->CharData, s, len, 0);
+}
+
+
+/*
+ * Parse an XRDS document.
+ * If an OpenID Provider URL is discovered, op_url to that value and return nonzero.
+ * If nothing useful happened, return 0.
+ */
+int parse_xrds_document(StrBuf *ReplyBuf) {
+ ctdl_openid *oiddata = (ctdl_openid *) CC->openid_data;
+ struct xrds xrds;
+ int return_value = 0;
+
+ /* syslog(LOG_DEBUG, "XRDS document:\n%s\n", ChrPtr(ReplyBuf)); */
+
+ memset(&xrds, 0, sizeof (struct xrds));
+ xrds.selected_service_priority = INT_MAX;
+ xrds.CharData = NewStrBuf();
+ xrds.current_service_uri = NewStrBuf();
+ xrds.selected_service_uri = NewStrBuf();
+ XML_Parser xp = XML_ParserCreate(NULL);
+ if (xp) {
+ XML_SetUserData(xp, &xrds);
+ XML_SetElementHandler(xp, xrds_xml_start, xrds_xml_end);
+ XML_SetCharacterDataHandler(xp, xrds_xml_chardata);
+ XML_Parse(xp, ChrPtr(ReplyBuf), StrLength(ReplyBuf), 0);
+ XML_Parse(xp, "", 0, 1);
+ XML_ParserFree(xp);
+ }
+ else {
+ syslog(LOG_ALERT, "Cannot create XML parser");
+ }
+
+ if (xrds.selected_service_priority < INT_MAX) {
+ if (oiddata->op_url == NULL) {
+ oiddata->op_url = NewStrBuf();
+ }
+ FlushStrBuf(oiddata->op_url);
+ StrBufAppendBuf(oiddata->op_url, xrds.selected_service_uri, 0);
+ return_value = openid_disco_xrds;
+ }
+
+ FreeStrBuf(&xrds.CharData);
+ FreeStrBuf(&xrds.current_service_uri);
+ FreeStrBuf(&xrds.selected_service_uri);
+
+ return(return_value);
+}
+
+
+
+/*
+ * Callback function for perform_openid2_discovery()
+ * We're interested in the X-XRDS-Location: header.
+ */
+size_t yadis_headerfunction(void *ptr, size_t size, size_t nmemb, void *userdata) {
+ char hdr[1024];
+ StrBuf **x_xrds_location = (StrBuf **) userdata;
+
+ memcpy(hdr, ptr, (size*nmemb));
+ hdr[size*nmemb] = 0;
+
+ if (!strncasecmp(hdr, "X-XRDS-Location:", 16)) {
+ *x_xrds_location = NewStrBufPlain(&hdr[16], ((size*nmemb)-16));
+ StrBufTrim(*x_xrds_location);
+ }
+
+ return(size * nmemb);
+}
+
+
+/* Attempt to perform Yadis discovery as specified in Yadis 1.0 section 6.2.5.
+ *
+ * If Yadis fails, we then attempt HTML discovery using the same document.
+ *
+ * If successful, returns nonzero and calls parse_xrds_document() to act upon the received data.
+ * If fails, returns 0 and does nothing else.
+ */
+int perform_openid2_discovery(StrBuf *SuppliedURL) {
+ ctdl_openid *oiddata = (ctdl_openid *) CC->openid_data;
+ int docbytes = (-1);
+ StrBuf *ReplyBuf = NULL;
+ int return_value = 0;
+ CURL *curl;
+ CURLcode result;
+ char errmsg[1024] = "";
+ struct curl_slist *my_headers = NULL;
+ StrBuf *x_xrds_location = NULL;
+
+ if (!SuppliedURL) return(0);
+ syslog(LOG_DEBUG, "perform_openid2_discovery(%s)", ChrPtr(SuppliedURL));
+ if (StrLength(SuppliedURL) == 0) return(0);
+
+ ReplyBuf = NewStrBuf();
+ if (!ReplyBuf) return(0);
+
+ curl = ctdl_openid_curl_easy_init(errmsg);
+ if (!curl) return(0);
+
+ curl_easy_setopt(curl, CURLOPT_URL, ChrPtr(SuppliedURL));
+ curl_easy_setopt(curl, CURLOPT_WRITEDATA, ReplyBuf);
+ curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, CurlFillStrBuf_callback);
+
+ my_headers = curl_slist_append(my_headers, "Accept:"); /* disable the default Accept: header */
+ my_headers = curl_slist_append(my_headers, "Accept: application/xrds+xml");
+ curl_easy_setopt(curl, CURLOPT_HTTPHEADER, my_headers);
+
+ curl_easy_setopt(curl, CURLOPT_WRITEHEADER, &x_xrds_location);
+ curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, yadis_headerfunction);
+
+ result = curl_easy_perform(curl);
+ if (result) {
+ syslog(LOG_DEBUG, "libcurl error %d: %s", result, errmsg);
+ }
+ curl_slist_free_all(my_headers);