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
@@ -194,196 +194,196 @@ namespace opkele {
             unsigned char *md = HMAC(
                     EVP_sha1(),
                     &(secret.front()),secret.size(),
                     (const unsigned char *)kv.data(),kv.length(),
                     0,&md_len);
             if(sig.size()!=md_len || memcmp(&(sig.front()),md,md_len))
                 throw id_res_mismatch(OPKELE_CP_ "signature mismatch");
         }catch(failed_lookup& e) { /* XXX: more specific? */
             const string& slist = pin.get_param("openid.signed");
             string::size_type pp = 0;
             params_t p;
             while(true) {
                 string::size_type co = slist.find(',',pp);
                 string f = "openid.";
                 f += (co==string::npos)?slist.substr(pp):slist.substr(pp,co-pp);
                 p[f] = pin.get_param(f);
                 if(co==string::npos)
                     break;
                 pp = co+1;
             }
             p["openid.assoc_handle"] = pin.get_param("openid.assoc_handle");
             p["openid.sig"] = pin.get_param("openid.sig");
             p["openid.signed"] = pin.get_param("openid.signed");
             try {
                 string ih = pin.get_param("openid.invalidate_handle");
                 p["openid.invalidate_handle"] = ih;
             }catch(failed_lookup& fl) { }
             try {
                 check_authentication(server,p);
             }catch(failed_check_authentication& fca) {
                 throw id_res_failed(OPKELE_CP_ "failed to check_authentication()");
             }
         }
         if(ext) ext->id_res_hook(pin,ps,identity);
     }
 
     void consumer_t::check_authentication(const string& server,const params_t& p) {
         string request = "openid.mode=check_authentication";
         for(params_t::const_iterator i=p.begin();i!=p.end();++i) {
             if(i->first!="openid.mode") {
                 request += '&';
                 request += i->first;
                 request += '=';
                 request += util::url_encode(i->second);
             }
         }
         curl_t curl = curl_easy_init();
         if(!curl)
             throw exception_curl(OPKELE_CP_ "failed to curl_easy_init()");
         string response;
         CURLcode r;
         (r=curl_misc_sets(curl))
         || (r=curl_easy_setopt(curl,CURLOPT_URL,server.c_str()))
         || (r=curl_easy_setopt(curl,CURLOPT_POST,1))
         || (r=curl_easy_setopt(curl,CURLOPT_POSTFIELDS,request.data()))
         || (r=curl_easy_setopt(curl,CURLOPT_POSTFIELDSIZE,request.length()))
         || (r=curl_easy_setopt(curl,CURLOPT_WRITEFUNCTION,_curl_tostring))
         || (r=curl_easy_setopt(curl,CURLOPT_WRITEDATA,&response))
         ;
         if(r)
             throw exception_curl(OPKELE_CP_ "failed to curl_easy_setopt()",r);
         if(r=curl_easy_perform(curl))
             throw exception_curl(OPKELE_CP_ "failed to curl_easy_perform()",r);
         params_t pp; pp.parse_keyvalues(response);
         if(pp.has_param("invalidate_handle"))
             invalidate_assoc(server,pp.get_param("invalidate_handle"));
         if(pp.has_param("is_valid")) {
             if(pp.get_param("is_valid")=="true")
                 return;
         }else if(pp.has_param("lifetime")) {
             if(util::string_to_long(pp.get_param("lifetime")))
                 return;
         }
         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;
             }
         }
 #elif defined(USE_PCREPP)
         pcrepp::Pcre bre("<body\\b",PCRE_CASELESS);
         if(bre.search(html))
             html.erase(bre.get_match_start());
         pcrepp::Pcre hdre(re_hdre,PCRE_CASELESS);
         if(!hdre.search(html))
             throw bad_input(OPKELE_CP_ "failed to find head");
         html.erase(0,hdre.get_match_end()+1);
         pcrepp::Pcre lre(re_lre,PCRE_CASELESS), rre(re_rre,PCRE_CASELESS), hre(re_hre,PCRE_CASELESS);
         while(lre.search(html)) {
             string attrs = lre[0];
             html.erase(0,lre.get_match_end()+1);
             if(!(rre.search(attrs)&&hre.search(attrs)))
                 continue;
             if(rre[0]=="openid.server") {
                 server = hre[0];
                 if(!delegate.empty())
                     break;
             }else if(rre[0]=="openid.delegate") {
                 delegate = hre[0];
                 if(!server.empty())
                     break;
             }
         }
 #else
         #error "I must have gone crazy"
 #endif
         if(server.empty())
             throw failed_assertion(OPKELE_CP_ "The location has no openid.server declaration");
 #else /* none of the RE bindings enabled */
         throw not_implemented(OPKELE_CP_ "No internal implementation of retrieve_links were provided at compile-time");
 #endif
     }
 
     assoc_t consumer_t::find_assoc(const string& server) {
         throw failed_lookup(OPKELE_CP_ "no find_assoc() provided");
     }
 
     string consumer_t::normalize(const string& url) {
         string rv = url;
         // strip leading and trailing spaces
         string::size_type i = rv.find_first_not_of(" \t\r\n");
         if(i==string::npos)
             throw bad_input(OPKELE_CP_ "empty URL");
         if(i)
             rv.erase(0,i);
         i = rv.find_last_not_of(" \t\r\n");
         assert(i!=string::npos);
         if(i<(rv.length()-1))
             rv.erase(i+1);
         // add missing http://
         i = rv.find("://");
         if(i==string::npos) { // primitive. but do we need more?
             rv.insert(0,"http://");
             i = sizeof("http://")-1;
         }else{
             i += sizeof("://")-1;
         }
         string::size_type qm = rv.find('?',i);
         string::size_type sl = rv.find('/',i);
         if(qm!=string::npos) {
             if(sl==string::npos || sl>qm)
                 rv.insert(qm,1,'/');
         }else{
             if(sl==string::npos)
                 rv += '/';
         }
         return rv;
     }
 
     string consumer_t::canonicalize(const string& url) {
         string rv = normalize(url);