adam@1: #include <string.h>
adam@1: 
adam@0: #include <openssl/sha.h>
adam@0: #include <curl/curl.h>
adam@1: #include <expat.h>
adam@0: 
adam@1: #include <openid.h>
adam@0: 
adam@0: uw_unit uw_OpenidFfi_init(uw_context ctx) {
adam@0:   curl_global_init(CURL_GLOBAL_ALL);
adam@0: 
adam@0:   return uw_unit_v;
adam@0: }
adam@1: 
adam@1: static CURL *curl(uw_context ctx) {
adam@1:   CURL *r;
adam@1: 
adam@1:   if (!(r = uw_get_global(ctx, "curl"))) {
adam@1:     r = curl_easy_init();
adam@1:     if (r)
adam@1:       uw_set_global(ctx, "curl", r, curl_easy_cleanup);
adam@1:   }
adam@1: 
adam@1:   return r;
adam@1: }
adam@1: 
adam@1: typedef struct {
adam@1:   uw_context ctx;
adam@1:   char *result;
adam@1: } endpoint;
adam@1: 
adam@1: static void XMLCALL startElement(void *userData, const XML_Char *name, const XML_Char **atts) {
adam@1:   endpoint *ep = userData;
adam@1: 
adam@1:   if (!strcmp(name, "link")) {
adam@1:     const XML_Char **attp;
adam@1:     int found = 0;
adam@1: 
adam@1:     for (attp = atts; *attp; attp += 2) {
adam@1:       if (!strcmp(attp[0], "rel") && !strcmp(attp[1], "openid2.provider")) {
adam@1:         found = 1;
adam@1:         break;
adam@1:       }
adam@1:     }
adam@1: 
adam@1:     if (found) {
adam@1:       for (attp = atts; *attp; attp += 2) {
adam@1:         if (!strcmp(attp[0], "href")) {
adam@1:           ep->result = uw_strdup(ep->ctx, attp[1]);
adam@1:           return;
adam@1:         }
adam@1:       }
adam@1:     }
adam@1:   }
adam@1: }
adam@1: 
adam@1: static void XMLCALL endElement(void *userData, const XML_Char *name) {
adam@1: }
adam@1: 
adam@1: typedef struct {
adam@1:   XML_Parser parser;
adam@1:   int any_errors;
adam@1: } curl_data;
adam@1: 
adam@1: static size_t write_data(void *buffer, size_t size, size_t nmemb, void *userp) {
adam@1:   curl_data *d = userp;
adam@1: 
adam@1:   if (!XML_Parse(d->parser, buffer, size * nmemb, 0))
adam@1:     d->any_errors = 1;
adam@1: 
adam@1:   return size * nmemb;
adam@1: }
adam@1: 
adam@1: uw_Basis_string uw_OpenidFfi_discover(uw_context ctx, uw_Basis_string id) {
adam@1:   char *s;
adam@1:   CURL *c = curl(ctx);
adam@1:   curl_data cd = {};
adam@1:   endpoint ep = {ctx};
adam@1:   CURLcode code;
adam@1: 
adam@1:   if (!strchr(id, ':')) {
adam@1:     id = uw_Basis_strcat(ctx, "http://", id);
adam@1:     if ((s = strchr(id, '#')) != NULL)
adam@1:       *s = 0;
adam@1:   } else if ((s = strchr(id, '#')) != NULL) {
adam@1:     char *id2 = uw_malloc(ctx, s - id + 1);
adam@1:     memcpy(id2, s, s - id);
adam@1:     id2[s - id] = 0;
adam@1:     id = id2;
adam@1:   }
adam@1: 
adam@1:   cd.parser = XML_ParserCreate(NULL);
adam@1:   XML_SetUserData(cd.parser, &ep);
adam@1:   uw_push_cleanup(ctx, (void (*)(void *))XML_ParserFree, cd.parser);
adam@1:   XML_SetElementHandler(cd.parser, startElement, endElement);
adam@1: 
adam@1:   curl_easy_setopt(c, CURLOPT_URL, id);
adam@1:   curl_easy_setopt(c, CURLOPT_WRITEFUNCTION, write_data);
adam@1:   curl_easy_setopt(c, CURLOPT_WRITEDATA, &cd);
adam@1: 
adam@1:   code = curl_easy_perform(c);
adam@1:   uw_pop_cleanup(ctx);
adam@1: 
adam@1:   if (code)
adam@1:     return NULL;
adam@1:   else
adam@1:     return ep.result;
adam@1: }