Minor improvements

- almost irrelevant documentation updates
- introduced id_res_expired_on_delivery exception to be thrown if the
  association has expired right before it could've been used for signature
  verification.

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

1 files changed, 3 insertions, 3 deletions

diff --git a/lib/consumer.cc b/lib/consumer.cc
index 66db7dd..9f7530f 100644
--- a/lib/consumer.cc
+++ b/lib/consumer.cc
@@ -1,413 +1,413 @@
 #include <algorithm>
 #include <cassert>
 #include <cstring>
 #include <opkele/util.h>
 #include <opkele/curl.h>
 #include <opkele/exception.h>
 #include <opkele/data.h>
 #include <opkele/consumer.h>
 #include <openssl/sha.h>
 #include <openssl/hmac.h>
 #include <iostream>
 
 #include "config.h"
 
 #include <pcre.h>
 
 namespace opkele {
     using namespace std;
     using util::curl_t;
 
     template<int lim>
         class curl_fetch_string_t : public curl_t {
             public:
                 curl_fetch_string_t(CURL *c)
                     : curl_t(c) { }
                 ~curl_fetch_string_t() throw() { }
 
                 string response;
 
                 size_t write(void *p,size_t size,size_t nmemb) {
                     size_t bytes = size*nmemb;
                     size_t get = min(lim-response.length(),bytes);
                     response.append((const char *)p,get);
                     return get;
                 }
         };
 
     typedef curl_fetch_string_t<16384> curl_pick_t;
 
     class pcre_matches_t {
         public:
             int *_ov;
             int _s;
 
             pcre_matches_t() : _ov(0), _s(0) { }
             pcre_matches_t(int s) : _ov(0), _s(s) {
                 if(_s&1) ++_s;
                 _s += _s>>1;
                 _ov = new int[_s];
             }
             ~pcre_matches_t() throw() { if(_ov) delete[] _ov; }
 
             int begin(int i) const { return _ov[i<<1]; }
             int end(int i) const { return _ov[(i<<1)+1]; }
             int length(int i) const { int t=i<<1; return _ov[t+1]-_ov[t]; }
     };
 
     class pcre_t {
         public:
             pcre *_p;
 
             pcre_t() : _p(0) { }
             pcre_t(pcre *p) : _p(p) { }
             pcre_t(const char *re,int opts) : _p(0) {
                 static const char *errptr; static int erroffset;
                 _p = pcre_compile(re,opts,&errptr,&erroffset,NULL);
                 if(!_p)
                     throw internal_error(OPKELE_CP_ string("Failed to compile regexp: ")+errptr);
             }
             ~pcre_t() throw() { if(_p) (*pcre_free)(_p); }
 
             pcre_t& operator=(pcre *p) { if(_p) (*pcre_free)(_p); _p=p; return *this; }
 
             operator const pcre*(void) const { return _p; }
             operator pcre*(void) { return _p; }
 
             int exec(const string& s,pcre_matches_t& m) {
                 if(!_p)
                     throw internal_error(OPKELE_CP_ "Trying to execute absent regexp");
                 return pcre_exec(_p,NULL,s.c_str(),s.length(),0,0,m._ov,m._s);
             }
     };
 
     assoc_t consumer_t::associate(const string& server) {
         util::dh_t dh = DH_new();
         if(!dh)
             throw exception_openssl(OPKELE_CP_ "failed to DH_new()");
         dh->p = util::dec_to_bignum(data::_default_p);
         dh->g = util::dec_to_bignum(data::_default_g);
         if(!DH_generate_key(dh))
             throw exception_openssl(OPKELE_CP_ "failed to DH_generate_key()");
         string request = 
             "openid.mode=associate"
             "&openid.assoc_type=HMAC-SHA1"
             "&openid.session_type=DH-SHA1"
             "&openid.dh_consumer_public=";
         request += util::url_encode(util::bignum_to_base64(dh->pub_key));
         curl_pick_t curl = curl_pick_t::easy_init();
         if(!curl)
             throw exception_curl(OPKELE_CP_ "failed to initialize curl");
         CURLcode r;
         (r=curl.misc_sets())
         || (r=curl.easy_setopt(CURLOPT_URL,server.c_str()))
         || (r=curl.easy_setopt(CURLOPT_POST,1))
         || (r=curl.easy_setopt(CURLOPT_POSTFIELDS,request.data()))
         || (r=curl.easy_setopt(CURLOPT_POSTFIELDSIZE,request.length()))
         || (r=curl.set_write())
         ;
         if(r)
             throw exception_curl(OPKELE_CP_ "failed to set curly options",r);
         if( (r=curl.easy_perform()) )
             throw exception_curl(OPKELE_CP_ "failed to perform curly request",r);
         params_t p; p.parse_keyvalues(curl.response);
         if(p.has_param("assoc_type") && p.get_param("assoc_type")!="HMAC-SHA1")
             throw bad_input(OPKELE_CP_ "unsupported assoc_type");
         string st;
         if(p.has_param("session_type")) st = p.get_param("session_type");
         if((!st.empty()) && st!="DH-SHA1")
             throw bad_input(OPKELE_CP_ "unsupported session_type");
         secret_t secret;
         if(st.empty()) {
             secret.from_base64(p.get_param("mac_key"));
         }else{
             util::bignum_t s_pub = util::base64_to_bignum(p.get_param("dh_server_public"));
             vector<unsigned char> ck(DH_size(dh)+1);
             unsigned char *ckptr = &(ck.front())+1;
             int cklen = DH_compute_key(ckptr,s_pub,dh);
             if(cklen<0)
                 throw exception_openssl(OPKELE_CP_ "failed to DH_compute_key()");
             if(cklen && (*ckptr)&0x80) {
                 (*(--ckptr)) = 0; ++cklen;
             }
             unsigned char key_sha1[SHA_DIGEST_LENGTH];
             SHA1(ckptr,cklen,key_sha1);
             secret.enxor_from_base64(key_sha1,p.get_param("enc_mac_key"));
         }
         int expires_in = 0;
         if(p.has_param("expires_in")) {
             expires_in = util::string_to_long(p.get_param("expires_in"));
         }else if(p.has_param("issued") && p.has_param("expiry")) {
             expires_in = util::w3c_to_time(p.get_param("expiry"))-util::w3c_to_time(p.get_param("issued"));
         }else
             throw bad_input(OPKELE_CP_ "no expiration information");
         return store_assoc(server,p.get_param("assoc_handle"),secret,expires_in);
     }
 
     string consumer_t::checkid_immediate(const string& identity,const string& return_to,const string& trust_root,extension_t *ext) {
         return checkid_(mode_checkid_immediate,identity,return_to,trust_root,ext);
     }
     string consumer_t::checkid_setup(const string& identity,const string& return_to,const string& trust_root,extension_t *ext) {
         return checkid_(mode_checkid_setup,identity,return_to,trust_root,ext);
     }
     string consumer_t::checkid_(mode_t mode,const string& identity,const string& return_to,const string& trust_root,extension_t *ext) {
         params_t p;
         if(mode==mode_checkid_immediate)
             p["mode"]="checkid_immediate";
         else if(mode==mode_checkid_setup)
             p["mode"]="checkid_setup";
         else
             throw bad_input(OPKELE_CP_ "unknown checkid_* mode");
         string iurl = canonicalize(identity);
         string server, delegate;
         retrieve_links(iurl,server,delegate);
         p["identity"] = delegate.empty()?iurl:delegate;
         if(!trust_root.empty())
             p["trust_root"] = trust_root;
         p["return_to"] = return_to;
         try {
             string ah = find_assoc(server)->handle();
             p["assoc_handle"] = ah;
         }catch(failed_lookup& fl) {
             string ah = associate(server)->handle();
             p["assoc_handle"] = ah;
         }
         if(ext) ext->checkid_hook(p,identity);
         return p.append_query(server);
     }
 
     void consumer_t::id_res(const params_t& pin,const string& identity,extension_t *ext) {
         if(pin.has_param("openid.user_setup_url"))
             throw id_res_setup(OPKELE_CP_ "assertion failed, setup url provided",pin.get_param("openid.user_setup_url"));
         string server,delegate;
         retrieve_links(identity.empty()?pin.get_param("openid.identity"):canonicalize(identity),server,delegate);
         params_t ps;
         try {
             assoc_t assoc = retrieve_assoc(server,pin.get_param("openid.assoc_handle"));
-            if(assoc->is_expired()) /* TODO: or should I throw some other exception to force programmer fix his implementation? */
-                throw failed_lookup(OPKELE_CP_ "retrieve_assoc() has returned expired handle");
+            if(assoc->is_expired())
+                throw id_res_expired_on_delivery(OPKELE_CP_ "retrieve_assoc() has returned expired handle");
             const string& sigenc = pin.get_param("openid.sig");
             vector<unsigned char> sig;
             util::decode_base64(sigenc,sig);
             const string& slist = pin.get_param("openid.signed");
             string kv;
             string::size_type p = 0;
             while(true) {
                 string::size_type co = slist.find(',',p);
                 string f = (co==string::npos)?slist.substr(p):slist.substr(p,co-p);
                 kv += f;
                 kv += ':';
                 f.insert(0,"openid.");
                 kv += pin.get_param(f);
                 kv += '\n';
                 if(ext) ps[f.substr(sizeof("openid.")-1)] = pin.get_param(f);
                 if(co==string::npos)
                     break;
                 p = co+1;
             }
             secret_t secret = assoc->secret();
             unsigned int md_len = 0;
             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? */
+        }catch(failed_lookup& e) {
             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_pick_t curl = curl_pick_t::easy_init();
         if(!curl)
             throw exception_curl(OPKELE_CP_ "failed to initialize curl");
         CURLcode r;
         (r=curl.misc_sets())
         || (r=curl.easy_setopt(CURLOPT_URL,server.c_str()))
         || (r=curl.easy_setopt(CURLOPT_POST,1))
         || (r=curl.easy_setopt(CURLOPT_POSTFIELDS,request.data()))
         || (r=curl.easy_setopt(CURLOPT_POSTFIELDSIZE,request.length()))
         || (r=curl.set_write())
         ;
         if(r)
             throw exception_curl(OPKELE_CP_ "failed to set curly options",r);
         if( (r=curl.easy_perform()) )
             throw exception_curl(OPKELE_CP_ "failed to perform curly request",r);
         params_t pp; pp.parse_keyvalues(curl.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) {
         server.erase();
         delegate.erase();
         curl_pick_t curl = curl_pick_t::easy_init();
         if(!curl)
             throw exception_curl(OPKELE_CP_ "failed to initialize curl");
         string& html = curl.response;
         CURLcode r;
         (r=curl.misc_sets())
         || (r=curl.easy_setopt(CURLOPT_URL,url.c_str()))
         || (r=curl.set_write());
         ;
         if(r)
             throw exception_curl(OPKELE_CP_ "failed to set curly options",r);
         r = curl.easy_perform();
         if(r && r!=CURLE_WRITE_ERROR)
             throw exception_curl(OPKELE_CP_ "failed to perform curly request",r);
         static const char *re_bre = "<\\s*body\\b", *re_hdre = "<\\s*head[^>]*>",
                      *re_lre = "<\\s*link\\b([^>]+)>",
                      *re_rre = "\\brel\\s*=\\s*['\"]([^'\"]+)['\"]",
                      *re_hre = "\\bhref\\s*=\\s*['\"]\\s*([^'\"\\s]+)\\s*['\"]";
         pcre_matches_t m1(3), m2(3);
         pcre_t bre(re_bre,PCRE_CASELESS);
         if(bre.exec(html,m1)>0)
             html.erase(m1.begin(0));
         pcre_t hdre(re_hdre,PCRE_CASELESS);
         if(hdre.exec(html,m1)<=0)
             throw bad_input(OPKELE_CP_ "failed to find <head>");
         html.erase(0,m1.end(0)+1);
         pcre_t lre(re_lre,PCRE_CASELESS), rre(re_rre,PCRE_CASELESS), hre(re_hre,PCRE_CASELESS);
         bool gotit = false;
         while( (!gotit) && lre.exec(html,m1)>=2 ) {
             static const char *whitespace = " \t";
             string attrs(html,m1.begin(1),m1.length(1));
             html.erase(0,m1.end(0)+1);
             if(!( rre.exec(attrs,m1)>=2 && hre.exec(attrs,m2)>=2 ))
                 continue;
             string rels(attrs,m1.begin(1),m1.length(1));
             for(string::size_type ns = rels.find_first_not_of(whitespace);
                     ns!=string::npos;
                     ns=rels.find_first_not_of(whitespace,ns)) {
                 string::size_type s = rels.find_first_of(whitespace,ns);
                 string rel;
                 if(s==string::npos) {
                     rel.assign(rels,ns,string::npos);
                     ns=string::npos;
                 }else{
                     rel.assign(rels,ns,s-ns);
                     ns=s;
                 }
                 if(rel=="openid.server") {
                     server.assign(attrs,m2.begin(1),m2.length(1));
                     if(!delegate.empty()) {
                         gotit = true;
                         break;
                     }
                 }else if(rel=="openid.delegate") {
                     delegate.assign(attrs,m2.begin(1),m2.length(1));
                     if(!server.empty()) {
                         gotit = true;
                         break;
                     }
                 }
             }
         }
         if(server.empty())
             throw failed_assertion(OPKELE_CP_ "The location has no openid.server declaration");
     }
 
     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);
         curl_t curl = curl_t::easy_init();
         if(!curl)
             throw exception_curl(OPKELE_CP_ "failed to initialize curl()");
         string html;
         CURLcode r;
         (r=curl.misc_sets())
         || (r=curl.easy_setopt(CURLOPT_URL,rv.c_str()))
         || (r=curl.easy_setopt(CURLOPT_NOBODY,1))
         ;
         if(r)
             throw exception_curl(OPKELE_CP_ "failed to set curly options",r);
         r = curl.easy_perform();
         if(r)
             throw exception_curl(OPKELE_CP_ "failed to perform curly request",r);
         const char *eu = 0;
         r = curl.easy_getinfo(CURLINFO_EFFECTIVE_URL,&eu);
         if(r)
             throw exception_curl(OPKELE_CP_ "failed to get CURLINFO_EFFECTIVE_URL",r);
         rv = eu;
         return normalize(rv);
     }
 
 }