robustness improvements in link descovery mechanisms

accept stray spaces in link tags and inside relevant attribute values.

Thanks, Gen, for pointing it out.

Signed-off-by: Michael Krelin <hacker@klever.net>

1 files changed, 4 insertions, 4 deletions

diff --git a/lib/consumer.cc b/lib/consumer.cc
index 299b3bc..ff5da91 100644
--- a/lib/consumer.cc
+++ b/lib/consumer.cc
@@ -266,52 +266,52 @@ namespace opkele {
         }
         throw failed_check_authentication(OPKELE_CP_ "failed to verify response");
     }
 
     void consumer_t::retrieve_links(const string& url,string& server,string& delegate) {
 #if defined(USE_LIBPCRECPP) || defined(USE_PCREPP)
         server.erase();
         delegate.erase();
         curl_t curl = curl_easy_init();
         if(!curl)
             throw exception_curl(OPKELE_CP_ "failed to curl_easy_init()");
         string html;
         CURLcode r;
         (r=curl_misc_sets(curl))
         || (r=curl_easy_setopt(curl,CURLOPT_URL,url.c_str()))
         || (r=curl_easy_setopt(curl,CURLOPT_WRITEFUNCTION,_curl_tostring))
         || (r=curl_easy_setopt(curl,CURLOPT_WRITEDATA,&html))
         ;
         if(r)
             throw exception_curl(OPKELE_CP_ "failed to curl_easy_setopt()",r);
         r = curl_easy_perform(curl);
         if(r && r!=CURLE_WRITE_ERROR)
             throw exception_curl(OPKELE_CP_ "failed to curl_easy_perform()",r);
         // strip out everything past body
-        static const char *re_hdre = "<head[^>]*>",
-                     *re_lre = "<link\\b([^>]+)>",
-                     *re_rre = "\\brel=['\"]([^'\"]+)['\"]",
-                     *re_hre = "\\bhref=['\"]([^'\"]+)['\"]";
+        static const char *re_hdre = "<\\s*head[^>]*>",
+                     *re_lre = "<\\s*link\\b([^>]+)>",
+                     *re_rre = "\\brel\\s*=\\s*['\"]\\s*([^'\"\\s]+)\\s*['\"]",
+                     *re_hre = "\\bhref\\s*=\\s*['\"]\\s*([^'\"\\s]+)\\s*['\"]";
 #if defined(USE_LIBPCRECPP)
         static pcrecpp::RE_Options ro(PCRE_CASELESS|PCRE_DOTALL);
         static pcrecpp::RE
             bre("<body\\b.*",ro), hdre(re_hdre,ro),
             lre(re_lre,ro), rre(re_rre), hre(re_hre,ro);
         bre.Replace("",&html);
         pcrecpp::StringPiece hpiece(html);
         if(!hdre.FindAndConsume(&hpiece))
             throw bad_input(OPKELE_CP_ "failed to find head");
         string attrs;
         while(lre.FindAndConsume(&hpiece,&attrs)) {
             pcrecpp::StringPiece rel, href;
             if(!(rre.PartialMatch(attrs,&rel) && hre.PartialMatch(attrs,&href)))
                 continue;
             if(rel=="openid.server") {
                 href.CopyToString(&server);
                 if(!delegate.empty())
                     break;
             }else if(rel=="openid.delegate") {
                 href.CopyToString(&delegate);
                 if(!server.empty())
                     break;
             }
         }