the whole library rewritten

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

12 files changed, 871 insertions, 167 deletions

diff --git a/lib/Makefile.am b/lib/Makefile.am
index 989de28..c58ec3f 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -1,31 +1,34 @@
 lib_LTLIBRARIES = libopkele.la
 
 AM_CPPFLAGS = ${CPPFLAGS_DEBUG}
 DEFAULT_INCLUDES = -I${top_builddir}
 INCLUDES = \
-           -I${top_srcdir}/include/ \
+           -I${top_builddir}/include/ -I${top_srcdir}/include/ \
            ${KONFORKA_CFLAGS} \
            ${OPENSSL_CFLAGS} \
            ${LIBCURL_CPPFLAGS} \
            ${PCRE_CFLAGS} ${EXPAT_CFLAGS} ${TIDY_CFLAGS}
 libopkele_la_LIBADD = \
         ${LIBCURL} \
         ${PCRE_LIBS} ${EXPAT_LIBS} \
         ${OPENSSL_LIBS} \
         ${KONFORKA_LIBS} ${TIDY_LIBS}
 
 libopkele_la_SOURCES = \
                        params.cc \
                        util.cc \
                        server.cc \
                        secret.cc \
                        data.cc \
                        consumer.cc \
                        exception.cc \
                        extension.cc \
                        sreg.cc \
                        extension_chain.cc \
                        curl.cc expat.cc \
-                       discovery.cc
+                       discovery.cc \
+                       basic_rp.cc \
+                       prequeue_rp.cc \
+                       openid_message.cc
 libopkele_la_LDFLAGS = \
         -version-info 2:0:0
diff --git a/lib/basic_rp.cc b/lib/basic_rp.cc
new file mode 100644
index 0000000..763a391
--- a/dev/null
+++ b/lib/basic_rp.cc
@@ -0,0 +1,311 @@
+#include <openssl/sha.h>
+#include <openssl/hmac.h>
+#include <opkele/basic_rp.h>
+#include <opkele/exception.h>
+#include <opkele/uris.h>
+#include <opkele/data.h>
+#include <opkele/util.h>
+#include <opkele/curl.h>
+
+namespace opkele {
+
+    static void dh_get_secret(
+            secret_t& secret, const basic_openid_message& om,
+            const char *exp_assoc, const char *exp_sess,
+            util::dh_t& dh,
+            size_t d_len, unsigned char *(*d_fun)(const unsigned char*,size_t,unsigned char*) ) try {
+        if(om.get_field("assoc_type")!=exp_assoc || om.get_field("session_type")!=exp_sess)
+            throw bad_input(OPKELE_CP_ "Unexpected associate response");
+        util::bignum_t s_pub = util::base64_to_bignum(om.get_field("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_digest[d_len];
+        secret.enxor_from_base64((*d_fun)(ckptr,cklen,key_digest),om.get_field("enc_mac_key"));
+    }catch(opkele::failed_lookup& ofl) {
+        throw bad_input(OPKELE_CP_ "Incoherent response from OP");
+    } OPKELE_RETHROW
+
+    static void direct_request(basic_openid_message& oum,const basic_openid_message& inm,const string& OP) {
+        util::curl_pick_t curl = util::curl_pick_t::easy_init();
+        if(!curl)
+            throw exception_curl(OPKELE_CP_ "failed to initialize curl");
+        string request = inm.query_string();
+        CURLcode r;
+        (r=curl.misc_sets())
+            || (r=curl.easy_setopt(CURLOPT_URL,OP.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);
+        oum.from_keyvalues(curl.response);
+    }
+
+
+    assoc_t basic_RP::associate(const string& OP) {
+        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()");
+        openid_message_t req;
+        req.set_field("ns",OIURI_OPENID20);
+        req.set_field("mode","associate");
+        req.set_field("dh_modulus",util::bignum_to_base64(dh->p));
+        req.set_field("dh_gen",util::bignum_to_base64(dh->g));
+        req.set_field("dh_consumer_public",util::bignum_to_base64(dh->pub_key));
+        openid_message_t res;
+        req.set_field("assoc_type","HMAC-SHA256");
+        req.set_field("session_type","DH-SHA256");
+        secret_t secret;
+        int expires_in;
+        try {
+            direct_request(res,req,OP);
+            dh_get_secret( secret, res,
+                    "HMAC-SHA256", "DH-SHA256",
+                    dh, SHA256_DIGEST_LENGTH, SHA256 );
+            expires_in = util::string_to_long(res.get_field("expires_in"));
+        }catch(exception& e) {
+            try {
+                req.set_field("assoc_type","HMAC-SHA1");
+                req.set_field("session_type","DH-SHA1");
+                direct_request(res,req,OP);
+                dh_get_secret( secret, res,
+                        "HMAC-SHA1", "DH-SHA1",
+                        dh, SHA_DIGEST_LENGTH, SHA1 );
+                expires_in = util::string_to_long(res.get_field("expires_in"));
+            }catch(bad_input& e) {
+                throw dumb_RP(OPKELE_CP_ "OP failed to supply an association");
+            }
+        }
+        return store_assoc(
+                OP, res.get_field("assoc_handle"),
+                res.get_field("assoc_type"), secret,
+                expires_in );
+    }
+
+    basic_openid_message& basic_RP::checkid_(
+            basic_openid_message& rv,
+            mode_t mode,
+            const string& return_to,const string& realm,
+            extension_t *ext) {
+        rv.reset_fields();
+        rv.set_field("ns",OIURI_OPENID20);
+        if(mode==mode_checkid_immediate)
+            rv.set_field("mode","checkid_immediate");
+        else if(mode==mode_checkid_setup)
+            rv.set_field("mode","checkid_setup");
+        else
+            throw bad_input(OPKELE_CP_ "unknown checkid_* mode");
+        if(realm.empty() && return_to.empty())
+            throw bad_input(OPKELE_CP_ "At least one of realm and return_to must be non-empty");
+        if(!realm.empty()) {
+            rv.set_field("realm",realm);
+            rv.set_field("trust_root",realm);
+        }
+        if(!return_to.empty())
+            rv.set_field("return_to",return_to);
+        const openid_endpoint_t& ep = get_endpoint();
+        rv.set_field("claimed_id",ep.claimed_id);
+        rv.set_field("identity",ep.local_id);
+        try {
+            rv.set_field("assoc_handle",find_assoc(ep.uri)->handle());
+        }catch(dumb_RP& drp) {
+        }catch(failed_lookup& fl) {
+            try {
+                rv.set_field("assoc_handle",associate(ep.uri)->handle());
+            }catch(dumb_RP& drp) { }
+        } OPKELE_RETHROW
+        if(ext) ext->checkid_hook(rv);
+        return rv;
+    }
+
+    class signed_part_message_proxy : public basic_openid_message {
+        public:
+            const basic_openid_message& x;
+            set<string> signeds;
+
+            signed_part_message_proxy(const basic_openid_message& xx) : x(xx) {
+                const string& slist = x.get_field("signed");
+                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);
+                    signeds.insert(f);
+                    if(co==string::npos) break;
+                    p = co+1;
+                }
+            }
+
+            bool has_field(const string& n) const {
+                return signeds.find(n)!=signeds.end() && x.has_field(n); }
+            const string& get_field(const string& n) const {
+                if(signeds.find(n)==signeds.end())
+                    throw failed_lookup(OPKELE_CP_ "The field isn't known to be signed");
+                return x.get_field(n); }
+
+            fields_iterator fields_begin() const {
+                return signeds.begin(); }
+            fields_iterator fields_end() const {
+                return signeds.end(); }
+    };
+
+    static void parse_query(const string& u,string::size_type q,
+            map<string,string>& p) {
+        if(q==string::npos)
+            return;
+        assert(u[q]=='?');
+        ++q;
+        string::size_type l = u.size();
+        while(q<l) {
+            string::size_type eq = u.find('=',q);
+            string::size_type am = u.find('&',q);
+            if(am==string::npos) {
+                if(eq==string::npos) {
+                    p[""] = u.substr(q);
+                }else{
+                    p[u.substr(q,eq-q)] = u.substr(eq+1);
+                }
+                break;
+            }else{
+                if(eq==string::npos || eq>am) {
+                    p[""] = u.substr(q,eq-q);
+                }else{
+                    p[u.substr(q,eq-q)] = u.substr(eq+1,am-eq-1);
+                }
+                q = ++am;
+            }
+        }
+    }
+
+    void basic_RP::id_res(const basic_openid_message& om,extension_t *ext) {
+        bool o2 = om.has_field("ns")
+            && om.get_field("ns")==OIURI_OPENID20;
+        if( (!o2) && om.has_field("user_setup_url"))
+            throw id_res_setup(OPKELE_CP_ "assertion failed, setup url provided",
+                    om.get_field("user_setup_url"));
+        string m = om.get_field("mode");
+        if(o2 && m=="setup_needed")
+            throw id_res_setup(OPKELE_CP_ "setup needed, no setup url provided");
+        if(m=="cancel")
+            throw id_res_cancel(OPKELE_CP_ "authentication cancelled");
+        bool go_dumb=false;
+        try {
+            string OP = o2
+                ?om.get_field("op_endpoint")
+                :get_endpoint().uri;
+            assoc_t assoc = retrieve_assoc(
+                    OP,om.get_field("assoc_handle"));
+            if(om.get_field("sig")!=util::base64_signature(assoc,om))
+                throw id_res_mismatch(OPKELE_CP_ "signature mismatch");
+        }catch(dumb_RP& drp) {
+            go_dumb=true;
+        }catch(failed_lookup& e) {
+            go_dumb=true;
+        } OPKELE_RETHROW
+        if(go_dumb) {
+            try {
+                string OP = o2
+                    ?om.get_field("op_endpoint")
+                    :get_endpoint().uri;
+                check_authentication(OP,om);
+            }catch(failed_check_authentication& fca) {
+                throw id_res_failed(OPKELE_CP_ "failed to check_authentication()");
+            } OPKELE_RETHROW
+        }
+        signed_part_message_proxy signeds(om);
+        if(o2) {
+            check_nonce(om.get_field("op_endpoint"),
+                    om.get_field("response_nonce"));
+            static const char *mustsign[] = {
+                "op_endpoint", "return_to", "response_nonce", "assoc_handle",
+                "claimed_id", "identity" };
+            for(int ms=0;ms<(sizeof(mustsign)/sizeof(*mustsign));++ms) {
+                if(om.has_field(mustsign[ms]) && !signeds.has_field(mustsign[ms]))
+                    throw bad_input(OPKELE_CP_ string("Field '")+mustsign[ms]+"' is not signed against the specs");
+            }
+            if( (
+                    (om.has_field("claimed_id")?1:0)
+                    ^
+                    (om.has_field("identity")?1:0)
+                )&1 )
+                throw bad_input(OPKELE_CP_ "claimed_id and identity must be either both present or both absent");
+
+            string turl = util::rfc_3986_normalize_uri(get_this_url());
+            util::strip_uri_fragment_part(turl);
+            string rurl = util::rfc_3986_normalize_uri(om.get_field("return_to"));
+            util::strip_uri_fragment_part(rurl);
+            string::size_type
+                tq = turl.find('?'), rq = rurl.find('?');
+            if(
+                    ((tq==string::npos)?turl:turl.substr(0,tq))
+                    !=
+                    ((rq==string::npos)?rurl:rurl.substr(0,rq))
+              )
+                throw id_res_bad_return_to(OPKELE_CP_ "return_to url doesn't match request url");
+            map<string,string> tp; parse_query(turl,tq,tp);
+            map<string,string> rp; parse_query(rurl,rq,rp);
+            for(map<string,string>::const_iterator rpi=rp.begin();rpi!=rp.end();++rpi) {
+                map<string,string>::const_iterator tpi = tp.find(rpi->first);
+                if(tpi==tp.end())
+                    throw id_res_bad_return_to(OPKELE_CP_ string("Parameter '")+rpi->first+"' from return_to is missing from the request");
+                if(tpi->second!=rpi->second)
+                    throw id_res_bad_return_to(OPKELE_CP_ string("Parameter '")+rpi->first+"' from return_to doesn't matche the request");
+            }
+
+            if(om.has_field("claimed_id")) {
+                verify_OP(
+                        om.get_field("op_endpoint"),
+                        om.get_field("claimed_id"),
+                        om.get_field("identity") );
+            }
+
+        }
+        if(ext) ext->id_res_hook(om,signeds);
+    }
+
+    class check_auth_message_proxy : public basic_openid_message {
+        public:
+            const basic_openid_message& x;
+
+            check_auth_message_proxy(const basic_openid_message& xx) : x(xx) { }
+
+            bool has_field(const string& n) const { return x.has_field(n); }
+            const string& get_field(const string& n) const {
+                static const string checkauthmode="check_authentication";
+                return (n=="mode")?checkauthmode:x.get_field(n); }
+            bool has_ns(const string& uri) const {return x.has_ns(uri); }
+            string get_ns(const string& uri) const { return x.get_ns(uri); }
+            fields_iterator fields_begin() const {
+                return x.fields_begin(); }
+            fields_iterator fields_end() const {
+                return x.fields_end(); }
+    };
+
+    void basic_RP::check_authentication(const string& OP,
+            const basic_openid_message& om){
+        openid_message_t res;
+        direct_request(res,check_auth_message_proxy(om),OP);
+        if(res.has_field("is_valid")) {
+            if(res.get_field("is_valid")=="true") {
+                if(res.has_field("invalidate_handle"))
+                    invalidate_assoc(OP,res.get_field("invalidate_handle"));
+                return;
+            }
+        }
+        throw failed_check_authentication(
+                OPKELE_CP_ "failed to verify response");
+    }
+
+}
diff --git a/lib/consumer.cc b/lib/consumer.cc
index 3c3b4f8..ebda262 100644
--- a/lib/consumer.cc
+++ b/lib/consumer.cc
@@ -29,325 +29,325 @@ namespace opkele {
                 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);
+        if(ext) ext->checkid_hook(p);
         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())
                 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) {
             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);
+        if(ext) ext->id_res_hook(pin,ps);
     }
 
     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?
diff --git a/lib/discovery.cc b/lib/discovery.cc
index d868308..93409f4 100644
--- a/lib/discovery.cc
+++ b/lib/discovery.cc
@@ -1,446 +1,537 @@
 #include <list>
 #include <opkele/curl.h>
 #include <opkele/expat.h>
 #include <opkele/uris.h>
 #include <opkele/discovery.h>
 #include <opkele/exception.h>
 #include <opkele/util.h>
 #include <opkele/tidy.h>
 #include <opkele/debug.h>
 
 #include "config.h"
 
 #define XRDS_HEADER "X-XRDS-Location"
 #define CT_HEADER "Content-Type"
 
 namespace opkele {
     using std::list;
     using xrd::XRD_t;
     using xrd::service_t;
 
+    /* TODO: the whole discovery thing needs cleanup and optimization due to
+     * many changes of concept. */
+
     static const char *whitespace = " \t\r\n";
     static const char *i_leaders = "=@+$!(";
     static const size_t max_html = 16384;
 
+    static const struct service_type_t {
+        const char *uri;
+        const char *forceid;
+    } service_types[] = {
+        { STURI_OPENID20_OP, IDURI_SELECT20 },
+        { STURI_OPENID20, 0 },
+        { STURI_OPENID11, 0 },
+        { STURI_OPENID10, 0 }
+    };
+    enum {
+        st_index_1 = 2, st_index_2 = 1
+    };
+
+
     static inline bool is_qelement(const XML_Char *n,const char *qen) {
         return !strcasecmp(n,qen);
     }
     static inline bool is_element(const XML_Char *n,const char *en) {
         if(!strcasecmp(n,en)) return true;
         int nl = strlen(n), enl = strlen(en);
         if( (nl>=(enl+1)) && n[nl-enl-1]=='\t'
                 && !strcasecmp(&n[nl-enl],en) )
             return true;
         return false;
     }
 
     static long element_priority(const XML_Char **a) {
         for(;*a;++a)
             if(!strcasecmp(*(a++),"priority")) {
                 long rv;
                 return (sscanf(*a,"%ld",&rv)==1)?rv:-1;
             }
         return -1;
     }
 
     class idigger_t : public util::curl_t, public util::expat_t {
         public:
             string xri_proxy;
 
             enum {
-                xmode_html = 1, xmode_xrd = 2
+                xmode_html = 1, xmode_xrd = 2, xmode_cid = 4
             };
             int xmode;
 
             string xrds_location;
             string http_content_type;
             service_t html_openid1;
             service_t html_openid2;
             string cdata_buf;
             long status_code;
             string status_string;
 
             typedef list<string> pt_stack_t;
             pt_stack_t pt_stack;
             int skipping;
             bool parser_choked;
             string save_html;
 
             XRD_t *xrd;
             service_t *xrd_service;
             string* cdata;
 
             idigger_t()
                 : util::curl_t(easy_init()),
                 util::expat_t(0),
                 xri_proxy(XRI_PROXY_URL) {
                     CURLcode r;
                     (r=misc_sets())
                         || (r=set_write())
                         || (r=set_header())
                         ;
                     if(r)
                         throw exception_curl(OPKELE_CP_ "failed to set curly options",r);
                 }
             ~idigger_t() throw() { }
 
-            void discover(idiscovery_t& result,const string& identity) {
-                result.clear();
+            string discover(endpoint_discovery_iterator& oi,const string& identity) {
+                string rv;
+                idiscovery_t idis;
                 string::size_type fsc = identity.find_first_not_of(whitespace);
                 if(fsc==string::npos)
-                    throw bad_input(OPKELE_CP_ "whtiespace-only identity");
+                    throw bad_input(OPKELE_CP_ "whitespace-only identity");
                 string::size_type lsc = identity.find_last_not_of(whitespace);
                 assert(lsc!=string::npos);
                 if(!strncasecmp(identity.c_str()+fsc,"xri://",sizeof("xri://")-1))
                     fsc += sizeof("xri://")-1;
                 if((fsc+1)>=lsc)
                     throw bad_input(OPKELE_CP_ "not a character of importance in identity");
                 string id(identity,fsc,lsc-fsc+1);
+                idis.clear();
                 if(strchr(i_leaders,id[0])) {
-                    result.normalized_id = id;
-                    result.xri_identity = true;
-                    /* TODO: further canonicalize xri identity? Like folding case  or whatever... */
-                    discover_at(
-                            result,
-                            xri_proxy + util::url_encode(id)+
-                            "?_xrd_r=application/xrd+xml;sep=false", xmode_xrd);
-                    if(status_code!=100)
-                        throw failed_xri_resolution(OPKELE_CP_
-                                "XRI resolution failed with '"+status_string+"' message",status_code);
-                    if(result.xrd.canonical_ids.empty())
-                        throw opkele::failed_discovery(OPKELE_CP_ "No CanonicalID for XRI identity found");
-                    result.canonicalized_id = result.xrd.canonical_ids.begin()->second;
+                    /* TODO: further normalize xri identity? Like folding case
+                     * or whatever... */
+                    rv = idis.normalized_id = id;
+                    idis.xri_identity = true;
+                    set<string> cids;
+                    for(const struct service_type_t *st=service_types;
+                            st<&service_types[sizeof(service_types)/sizeof(*service_types)];++st) {
+                        idis.clear();
+                        discover_at( idis,
+                                xri_proxy + util::url_encode(id)+
+                                "?_xrd_t="+util::url_encode(st->uri)+
+                                "&_xrd_r=application/xrd%2Bxml"
+                                ";sep=true;refs=true",
+                                xmode_xrd );
+                        if(status_code==241) continue;
+                        if(status_code!=100)
+                            throw failed_xri_resolution(OPKELE_CP_
+                                    "XRI resolution failed with '"+status_string+"' message"
+                                    ", while looking for SEP with type '"+st->uri+"'", status_code);
+                        if(idis.xrd.canonical_ids.empty())
+                            throw opkele::failed_discovery(OPKELE_CP_ "No CanonicalID found for XRI identity found");
+                        string cid = idis.xrd.canonical_ids.begin()->second;
+                        if(cids.find(cid)==cids.end()) {
+                            cids.insert(cid);
+                            idis.clear();
+                            discover_at( idis,
+                                    xri_proxy + util::url_encode(id)+
+                                    "?_xrd_t="+util::url_encode(st->uri)+
+                                    "&_xrd_r=application/xrd%2Bxml"
+                                    ";sep=true;refs=true",
+                                    xmode_xrd );
+                            if(status_code==241) continue;
+                            if(status_code!=100)
+                                throw failed_xri_resolution(OPKELE_CP_
+                                        "XRI resolution failed with '"+status_string+"' message"
+                                        ", while looking for SEP with type '"+st->uri+"'"
+                                        " on canonical id", status_code);
+                        }
+                        idis.canonicalized_id = cid;
+                        queue_endpoints(oi,idis,st);
+                    }
                 }else{
-                    result.xri_identity = false;
+                    idis.xri_identity = false;
                     if(id.find("://")==string::npos)
                         id.insert(0,"http://");
                     string::size_type fp = id.find('#');
                     if(fp!=string::npos) {
                         string::size_type qp = id.find('?');
                         if(qp==string::npos || qp<fp)
                             id.erase(fp);
                         else if(qp>fp)
                             id.erase(fp,qp-fp);
                     }
-                    result.normalized_id = util::rfc_3986_normalize_uri(id);
-                    discover_at(result,id,xmode_html|xmode_xrd);
+                    rv = idis.normalized_id = util::rfc_3986_normalize_uri(id);
+                    discover_at(idis,id,xmode_html|xmode_xrd);
                     const char * eu = 0;
                     CURLcode r = easy_getinfo(CURLINFO_EFFECTIVE_URL,&eu);
                     if(r)
                         throw exception_curl(OPKELE_CP_ "failed to get CURLINFO_EFFECTIVE_URL",r);
-                    result.canonicalized_id = util::rfc_3986_normalize_uri(eu); /* XXX: strip fragment part? */
+                    string cid = util::strip_uri_fragment_part( idis.canonicalized_id = util::rfc_3986_normalize_uri(eu) );
                     if(xrds_location.empty()) {
-                        html2xrd(result.xrd);
+                        html2xrd(oi,idis);
                     }else{
-                        discover_at(result,xrds_location,xmode_xrd);
-                        if(result.xrd.empty())
-                            html2xrd(result.xrd);
+                        idis.clear();
+                        idis.canonicalized_id = cid;
+                        discover_at(idis,xrds_location,xmode_xrd);
+                        if(idis.xrd.empty())
+                            html2xrd(oi,idis);
+                        else{
+                            for(const service_type_t *st=service_types;
+                                    st<&service_types[sizeof(service_types)/sizeof(*service_types)];++st)
+                                queue_endpoints(oi,idis,st);
+                        }
                     }
                 }
+                return rv;
             }
 
-            void discover_at(idiscovery_t& result,const string& url,int xm) {
+            void discover_at(idiscovery_t& idis,const string& url,int xm) {
+                DOUT_("Doing discovery at " << url);
                 CURLcode r = easy_setopt(CURLOPT_URL,url.c_str());
                 if(r)
                     throw exception_curl(OPKELE_CP_ "failed to set culry urlie",r);
 
                 http_content_type.clear();
                 xmode = xm;
                 prepare_to_parse();
                 if(xmode&xmode_html) {
                     xrds_location.clear();
                     save_html.clear();
                     save_html.reserve(max_html);
                 }
-                xrd = &result.xrd;
+                xrd = &idis.xrd;
 
                 r = easy_perform();
                 if(r && r!=CURLE_WRITE_ERROR)
                     throw exception_curl(OPKELE_CP_ "failed to perform curly request",r);
 
                 if(!parser_choked) {
                     parse(0,0,true);
                 }else{
                     /* TODO: do not bother if we've seen xml */
                     try {
                         util::tidy_doc_t td = util::tidy_doc_t::create();
                         if(!td)
                             throw exception_tidy(OPKELE_CP_ "failed to create htmltidy document");
 #ifndef NDEBUG
                         td.opt_set(TidyQuiet,false);
                         td.opt_set(TidyShowWarnings,false);
 #endif /* NDEBUG */
                         td.opt_set(TidyForceOutput,true);
                         td.opt_set(TidyXhtmlOut,true);
                         td.opt_set(TidyDoctypeMode,TidyDoctypeOmit);
                         td.opt_set(TidyMark,false);
                         if(td.parse_string(save_html)<=0)
                             throw exception_tidy(OPKELE_CP_ "tidy failed to parse document");
                         if(td.clean_and_repair()<=0)
                             throw exception_tidy(OPKELE_CP_ "tidy failed to clean and repair");
                         util::tidy_buf_t tide;
                         if(td.save_buffer(tide)<=0)
                             throw exception_tidy(OPKELE_CP_ "tidy failed to save buffer");
                         prepare_to_parse();
                         parse(tide.c_str(),tide.size(),true);
                     }catch(exception_tidy& et) { }
                 }
                 save_html.clear();
             }
 
             void prepare_to_parse() {
                 (*(expat_t*)this) = parser_create_ns();
                 set_user_data(); set_element_handler();
                 set_character_data_handler();
 
                 if(xmode&xmode_html) {
                     html_openid1.clear(); html_openid2.clear();
                     parser_choked = false;
                 }
 
                 cdata = 0; xrd_service = 0; skipping = 0;
+                pt_stack.clear();
                 status_code = 100; status_string.clear();
             }
 
-            void html2xrd(XRD_t& x) {
-                if(!html_openid1.uris.empty()) {
-                    html_openid1.types.insert(STURI_OPENID11);
-                    x.services.add(-1,html_openid1);
-                }
+            void html2xrd(endpoint_discovery_iterator& oi,idiscovery_t& id) {
+                XRD_t& x = id.xrd;
                 if(!html_openid2.uris.empty()) {
                     html_openid2.types.insert(STURI_OPENID20);
                     x.services.add(-1,html_openid2);
+                    queue_endpoints(oi,id,&service_types[st_index_2]);
+                }
+                if(!html_openid1.uris.empty()) {
+                    html_openid1.types.insert(STURI_OPENID11);
+                    x.services.add(-1,html_openid1);
+                    queue_endpoints(oi,id,&service_types[st_index_1]);
                 }
             }
 
             size_t write(void *p,size_t s,size_t nm) {
                 /* TODO: limit total size */
                 size_t bytes = s*nm;
                 const char *inbuf = (const char*)p;
                 if(xmode&xmode_html) {
                     size_t mbts = save_html.capacity()-save_html.size();
                     size_t bts = 0;
                     if(mbts>0) {
                         bts = (bytes>mbts)?mbts:bytes;
                         save_html.append(inbuf,bts);
                     }
                     if(skipping<0) return bts;
                 }
                 if(skipping<0) return 0;
                 bool rp = parse(inbuf,bytes,false);
                 if(!rp) {
                     parser_choked = true;
                     skipping = -1;
                     if(!(xmode&xmode_html))
                         bytes = 0;
                 }
                 return bytes;
             }
             size_t header(void *p,size_t s,size_t nm) {
                 size_t bytes = s*nm;
                 const char *h = (const char*)p;
                 const char *colon = (const char*)memchr(p,':',bytes);
                 const char *space = (const char*)memchr(p,' ',bytes);
                 if(space && ( (!colon) || space<colon ) ) {
                     xrds_location.clear(); http_content_type.clear();
                 }else if(colon) {
                     const char *hv = ++colon;
                     int hnl = colon-h;
                     int rb;
                     for(rb = bytes-hnl-1;rb>0 && isspace(*hv);++hv,--rb);
                     while(rb>0 && isspace(hv[rb-1])) --rb;
                     if(rb) {
                         if( (hnl>=sizeof(XRDS_HEADER))
                                 && !strncasecmp(h,XRDS_HEADER":",
                                     sizeof(XRDS_HEADER)) ) {
                             xrds_location.assign(hv,rb);
                         }else if( (hnl>=sizeof(CT_HEADER))
                                 && !strncasecmp(h,CT_HEADER":",
                                     sizeof(CT_HEADER)) ) {
                             const char *sc = (const char*)memchr(
                                     hv,';',rb);
                             http_content_type.assign(hv,sc?(sc-hv):rb);
                         }
                     }
                 }
                 return curl_t::header(p,s,nm);
             }
 
             void start_element(const XML_Char *n,const XML_Char **a) {
                 if(skipping<0) return;
                 if(skipping) {
                     if(xmode&xmode_html)
                         html_start_element(n,a);
                     ++skipping; return;
                 }
                 if(pt_stack.empty()) {
                     if(is_qelement(n,NSURI_XRDS "\tXRDS"))
                         return;
                     if(is_qelement(n,NSURI_XRD "\tXRD")) {
                         assert(xrd);
                         xrd->clear();
                         pt_stack.push_back(n);
                     }else if(xmode&xmode_html) {
                         html_start_element(n,a);
                     }else{
                         skipping = -1;
                     }
                 }else{
                     int pt_s = pt_stack.size();
                     if(pt_s==1) {
                         if(is_qelement(n,NSURI_XRD "\tCanonicalID")) {
                             assert(xrd);
                             cdata = &(xrd->canonical_ids.add(element_priority(a),string()));
                         }else if(is_qelement(n,NSURI_XRD "\tLocalID")) {
                             assert(xrd);
                             cdata = &(xrd->local_ids.add(element_priority(a),string()));
                         }else if(is_qelement(n,NSURI_XRD "\tProviderID")) {
                             assert(xrd);
                             cdata = &(xrd->provider_id);
                         }else if(is_qelement(n,NSURI_XRD "\tService")) {
                             assert(xrd);
                             xrd_service = &(xrd->services.add(element_priority(a),
                                         service_t()));
                             pt_stack.push_back(n);
                         }else if(is_qelement(n,NSURI_XRD "\tStatus")) {
                             for(;*a;) {
                                 if(!strcasecmp(*(a++),"code")) {
                                     if(sscanf(*(a++),"%ld",&status_code)==1 && status_code!=100) {
                                         cdata = &status_string;
                                         pt_stack.push_back(n);
                                         break;
                                     }
-                                }
+                                }else
+                                    ++a;
                             }
                         }else if(is_qelement(n,NSURI_XRD "\tExpires")) {
                             assert(xrd);
                             cdata_buf.clear();
                             cdata = &cdata_buf;
                         }else if(xmode&xmode_html) {
                             html_start_element(n,a);
                         }else{
                             skipping = 1;
                         }
                     }else if(pt_s==2) {
                         if(is_qelement(pt_stack.back().c_str(), NSURI_XRD "\tService")) {
                             if(is_qelement(n,NSURI_XRD "\tType")) {
                                 assert(xrd); assert(xrd_service);
                                 cdata_buf.clear();
                                 cdata = &cdata_buf;
                             }else if(is_qelement(n,NSURI_XRD "\tURI")) {
                                 assert(xrd); assert(xrd_service);
                                 cdata = &(xrd_service->uris.add(element_priority(a),string()));
                             }else if(is_qelement(n,NSURI_XRD "\tLocalID")
                                     || is_qelement(n,NSURI_OPENID10 "\tDelegate") ) {
                                 assert(xrd); assert(xrd_service);
                                 cdata = &(xrd_service->local_ids.add(element_priority(a),string()));
                             }else if(is_qelement(n,NSURI_XRD "\tProviderID")) {
                                     assert(xrd); assert(xrd_service);
                                     cdata = &(xrd_service->provider_id);
                             }else{
                                 skipping = 1;
                             }
                         }else
                             skipping = 1;
                     }else if(xmode&xmode_html) {
                         html_start_element(n,a);
                     }else{
                         skipping = 1;
                     }
                 }
             }
             void end_element(const XML_Char *n) {
                 if(skipping<0) return;
                 if(skipping) {
                     --skipping; return;
                 }
                 if(is_qelement(n,NSURI_XRD "\tType")) {
                     assert(xrd); assert(xrd_service); assert(cdata==&cdata_buf);
                     xrd_service->types.insert(cdata_buf);
                 }else if(is_qelement(n,NSURI_XRD "\tService")) {
                     assert(xrd); assert(xrd_service);
                     assert(!pt_stack.empty());
                     assert(pt_stack.back()==(NSURI_XRD "\tService"));
                     pt_stack.pop_back();
                     xrd_service = 0;
                 }else if(is_qelement(n,NSURI_XRD "\tStatus")) {
                     assert(xrd);
                     if(is_qelement(pt_stack.back().c_str(),n)) {
                         assert(cdata==&status_string);
                         pt_stack.pop_back();
                         if(status_code!=100)
                             skipping = -1;
                     }
                 }else if(is_qelement(n,NSURI_XRD "\tExpires")) {
                     assert(xrd);
                     xrd->expires = util::w3c_to_time(cdata_buf);
                 }else if((xmode&xmode_html) && is_element(n,"head")) {
                     skipping = -1;
                 }
                 cdata = 0;
             }
             void character_data(const XML_Char *s,int l) {
                 if(skipping) return;
                 if(cdata) cdata->append(s,l);
             }
 
             void html_start_element(const XML_Char *n,const XML_Char **a) {
                 if(is_element(n,"meta")) {
                     bool heq = false;
                     string l;
                     for(;*a;a+=2) {
                         if(!( strcasecmp(a[0],"http-equiv")
                                 || strcasecmp(a[1],XRDS_HEADER) ))
                             heq = true;
                         else if(!strcasecmp(a[0],"content"))
                             l.assign(a[1]);
                     }
                     if(heq)
                         xrds_location = l;
                 }else if(is_element(n,"link")) {
                     string rels;
                     string href;
                     for(;*a;a+=2) {
                         if( !strcasecmp(a[0],"rel") ) {
                             rels.assign(a[1]);
                         }else if( !strcasecmp(a[0],"href") ) {
                             const char *ns = a[1];
                             for(;*ns && isspace(*ns);++ns);
                             href.assign(ns);
                             string::size_type lns=href.find_last_not_of(whitespace);
                             href.erase(lns+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")
                             html_openid1.uris.add(-1,href);
                         else if(rel=="openid.delegate")
                             html_openid1.local_ids.add(-1,href);
                         else if(rel=="openid2.provider")
                             html_openid2.uris.add(-1,href);
                         else if(rel=="openid2.local_id")
                             html_openid2.local_ids.add(-1,href);
                     }
                 }else if(is_element(n,"body")) {
                     skipping = -1;
                 }
             }
 
+            void queue_endpoints(endpoint_discovery_iterator& oi,
+                    const idiscovery_t &id,
+                    const service_type_t *st) {
+                openid_endpoint_t ep;
+                ep.claimed_id = id.canonicalized_id;
+                for(xrd::services_t::const_iterator isvc=id.xrd.services.begin();
+                        isvc!=id.xrd.services.end(); ++isvc) {
+                    const xrd::service_t svc = isvc->second;
+                    if(svc.types.find(st->uri)==svc.types.end()) continue;
+                    for(xrd::uris_t::const_iterator iu=svc.uris.begin();iu!=svc.uris.end();++iu) {
+                        ep.uri = iu->second;
+                        if(st->forceid) {
+                            ep.local_id = ep.claimed_id = st->forceid;
+                            *(oi++) = ep;
+                        }else{
+                            if(svc.local_ids.empty()) {
+                                ep.local_id = ep.claimed_id;
+                                *(oi++) = ep;
+                            }else{
+                                for(xrd::local_ids_t::const_iterator ilid=svc.local_ids.begin();
+                                        ilid!=svc.local_ids.end(); ++ilid) {
+                                    ep.local_id = ilid->second;
+                                    *(oi++) = ep;
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+
     };
 
-    void idiscover(idiscovery_t& result,const string& identity) {
+    string idiscover(endpoint_discovery_iterator oi,const string& identity) {
         idigger_t idigger;
-        idigger.discover(result,identity);
+        return idigger.discover(oi,identity);
     }
 
 }
diff --git a/lib/extension.cc b/lib/extension.cc
index 8f22562..6451249 100644
--- a/lib/extension.cc
+++ b/lib/extension.cc
@@ -1,15 +1,15 @@
 #include <opkele/exception.h>
 #include <opkele/extension.h>
 
 namespace opkele {
 
-    void extension_t::checkid_hook(params_t& /* p */,const string& /* identity */ ) {
+    void extension_t::checkid_hook(basic_openid_message&) {
         throw not_implemented(OPKELE_CP_ "Consumer checkid_hook not implemented");
     }
-    void extension_t::id_res_hook(const params_t& /* p */,const params_t& /* sp */,const string& /* identity */) {
+    void extension_t::id_res_hook(const basic_openid_message&,const basic_openid_message&) {
         throw not_implemented(OPKELE_CP_ "Consumer id_res_hook not implemented");
     }
-    void extension_t::checkid_hook(const params_t& /* pin */,params_t& /* pout */) {
+    void extension_t::checkid_hook(const basic_openid_message&,basic_openid_message&) {
         throw not_implemented(OPKELE_CP_ "Server checkid_hook not implemented");
     }
 }
diff --git a/lib/extension_chain.cc b/lib/extension_chain.cc
index 16537dc..5c2afd9 100644
--- a/lib/extension_chain.cc
+++ b/lib/extension_chain.cc
@@ -1,16 +1,16 @@
 #include <cstdarg>
 #include <opkele/extension_chain.h>
 
 namespace opkele {
 
-    void extension_chain_t::checkid_hook(params_t& p,const string& identity) {
-        for(iterator i=begin();i!=end();++i) (*i)->checkid_hook(p,identity);
+    void extension_chain_t::checkid_hook(basic_openid_message& om){ 
+        for(iterator i=begin();i!=end();++i) (*i)->checkid_hook(om);
     }
-    void extension_chain_t::id_res_hook(const params_t& p,const params_t& sp,const string& identity) {
-        for(iterator i=begin();i!=end();++i) (*i)->id_res_hook(p,sp,identity);
+    void extension_chain_t::id_res_hook(const basic_openid_message& om,const basic_openid_message& sp) {
+        for(iterator i=begin();i!=end();++i) (*i)->id_res_hook(om,sp);
     }
-    void extension_chain_t::checkid_hook(const params_t& pin,params_t& pout) {
-        for(iterator i=begin();i!=end();++i) (*i)->checkid_hook(pin,pout);
+    void extension_chain_t::checkid_hook(const basic_openid_message& inm,basic_openid_message& oum) {
+        for(iterator i=begin();i!=end();++i) (*i)->checkid_hook(inm,oum);
     }
 
 }
diff --git a/lib/openid_message.cc b/lib/openid_message.cc
new file mode 100644
index 0000000..3b08748
--- a/dev/null
+++ b/lib/openid_message.cc
@@ -0,0 +1,228 @@
+#include <cassert>
+#include <opkele/types.h>
+#include <opkele/exception.h>
+#include <opkele/util.h>
+#include <opkele/debug.h>
+
+#include "config.h"
+
+namespace opkele {
+    using std::input_iterator_tag;
+    using std::unary_function;
+
+    struct __om_copier : public unary_function<const string&,void> {
+        public:
+            const basic_openid_message& from;
+            basic_openid_message& to;
+
+            __om_copier(basic_openid_message& to,const basic_openid_message& from)
+                : from(from), to(to) {
+                    to.reset_fields();
+                }
+
+            result_type operator()(argument_type f) {
+                to.set_field(f,from.get_field(f)); }
+    };
+
+    basic_openid_message::basic_openid_message(const basic_openid_message& x) {
+        x.copy_to(*this);
+    }
+    void basic_openid_message::copy_to(basic_openid_message& x) const {
+        for_each(fields_begin(),fields_end(),
+                __om_copier(x,*this) );
+    }
+
+    struct __om_ns_finder : public unary_function<const string&,bool> {
+        public:
+            const basic_openid_message& om;
+            const string& uri;
+
+            __om_ns_finder(const basic_openid_message& om,
+                    const string& uri) : om(om), uri(uri) { }
+
+            result_type operator()(argument_type f) {
+                return
+                    (!strncmp(f.c_str(),"ns.",sizeof("ns.")-1))
+                        && om.get_field(f)==uri ;
+            }
+    };
+
+    bool basic_openid_message::has_ns(const string& uri) const {
+        fields_iterator ei = fields_end();
+        fields_iterator i = find_if(fields_begin(),fields_end(),
+                __om_ns_finder(*this,uri));
+        return !(i==ei);
+    }
+    string basic_openid_message::get_ns(const string& uri) const {
+        fields_iterator ei = fields_end();
+        fields_iterator i = find_if(fields_begin(),fields_end(),
+                __om_ns_finder(*this,uri));
+        if(i==ei)
+            throw failed_lookup(OPKELE_CP_ string("failed to find namespace ")+uri);
+        return i->substr(3);
+    }
+
+    struct __om_query_builder : public unary_function<const string&,void> {
+        public:
+            const basic_openid_message& om;
+            string& rv;
+            bool first;
+
+            __om_query_builder(string& rv,const basic_openid_message& om)
+                : om(om), first(true), rv(rv) {
+                    for_each(om.fields_begin(),om.fields_end(),*this);
+                }
+            __om_query_builder(string& rv,const basic_openid_message& om,const string& url)
+                : om(om), first(true), rv(rv) {
+                    rv = url;
+                    if(rv.find('?')==string::npos)
+                        rv += '?';
+                    else
+                        first = false;
+                    for_each(om.fields_begin(),om.fields_end(),*this);
+                }
+
+            result_type operator()(argument_type f) {
+                if(first)
+                    first = false;
+                else
+                    rv += '&';
+                rv += "openid."; rv+= f;
+                rv += '=';
+                rv += util::url_encode(om.get_field(f));
+            }
+    };
+
+    string basic_openid_message::append_query(const string& url) const {
+        string rv;
+        return __om_query_builder(rv,*this,url).rv;
+    }
+    string basic_openid_message::query_string() const {
+        string rv;
+        return __om_query_builder(rv,*this).rv;
+    }
+
+    void basic_openid_message::reset_fields() {
+        throw not_implemented(OPKELE_CP_ "reset_fields() not implemented");
+    }
+    void basic_openid_message::set_field(const string& n,const string& v) {
+        throw not_implemented(OPKELE_CP_ "set_field() not implemented");
+    }
+    void basic_openid_message::reset_field(const string& n) {
+        throw not_implemented(OPKELE_CP_ "reset_field() not implemented");
+    }
+
+    void basic_openid_message::from_keyvalues(const string& kv) {
+        reset_fields();
+        string::size_type p = 0;
+        while(true) {
+            string::size_type co = kv.find(':',p);
+            if(co==string::npos)
+                break;
+#ifndef POSTELS_LAW
+            string::size_type nl = kv.find('\n',co+1);
+            if(nl==string::npos)
+                throw bad_input(OPKELE_CP_ "malformed input");
+            if(nl>co)
+                insert(value_type(kv.substr(p,co-p),kv.substr(co+1,nl-co-1)));
+            p = nl+1;
+#else /* POSTELS_LAW */
+            string::size_type lb = kv.find_first_of("\r\n",co+1);
+            if(lb==string::npos) {
+                set_field(kv.substr(p,co-p),kv.substr(co+1));
+                break;
+            }
+            if(lb>co)
+                set_field(kv.substr(p,co-p),kv.substr(co+1,lb-co-1));
+            string::size_type nolb = kv.find_first_not_of("\r\n",lb);
+            if(nolb==string::npos)
+                break;
+            p = nolb;
+#endif /* POSTELS_LAW */
+        }
+    }
+
+    void basic_openid_message::add_to_signed(const string& fields) {
+        string::size_type fnc = fields.find_first_not_of(",");
+        if(fnc==string::npos)
+            throw bad_input(OPKELE_CP_ "Trying to add nothing in particular to the list of signed fields");
+        string signeds;
+        try {
+            signeds = get_field("signed");
+            string::size_type lnc = signeds.find_last_not_of(",");
+            if(lnc==string::npos)
+                signeds.assign(fields,fnc,fields.size()-fnc);
+            else{
+                string::size_type ss = signeds.size();
+                if(lnc==(ss-1)) {
+                    signeds+= ',';
+                    signeds.append(fields,fnc,fields.size()-fnc);
+                }else{
+                    if(lnc<(ss-2))
+                        signeds.replace(lnc+2,ss-lnc-2,
+                                fields,fnc,fields.size()-fnc);
+                    else
+                        signeds.append(fields,fnc,fields.size()-fnc);
+                }
+            }
+        }catch(failed_lookup&) {
+            signeds.assign(fields,fnc,fields.size()-fnc);
+        }
+        set_field("signed",signeds);
+    }
+
+    string basic_openid_message::find_ns(const string& uri,const char *pfx) const {
+        if(has_field("ns"))
+            return get_ns(uri);
+        return pfx;
+    }
+    string basic_openid_message::allocate_ns(const string& uri,const char *pfx) {
+        if(!has_field("ns"))
+            return pfx;
+        if(has_ns(uri))
+            throw bad_input(OPKELE_CP_ "OpenID message already contains namespace");
+        string rv = pfx;
+        if(has_field("ns."+rv)) {
+            string::reference c=rv[rv.length()];
+            for(c='a';c<='z' && has_field("ns."+rv);++c);
+            if(c=='z')
+                throw exception(OPKELE_CP_ "Failed to allocate namespace");
+        }
+        set_field("ns."+rv,uri);
+        return rv;
+    }
+
+    void openid_message_t::copy_to(basic_openid_message& x) const {
+        x.reset_fields();
+        for(const_iterator i=begin();i!=end();++i)
+            x.set_field(i->first,i->second);
+    }
+
+    bool openid_message_t::has_field(const string& n) const {
+        return find(n)!=end();
+    }
+    const string& openid_message_t::get_field(const string& n) const {
+        const_iterator i=find(n);
+        if(i==end())
+            throw failed_lookup(OPKELE_CP_ n+": no such field");
+        return i->second;
+    }
+
+    openid_message_t::fields_iterator openid_message_t::fields_begin() const {
+        return util::map_keys_iterator<const_iterator,string,const string&,const string*>(begin(),end());
+    }
+    openid_message_t::fields_iterator openid_message_t::fields_end() const {
+        return util::map_keys_iterator<const_iterator,string,const string&,const string*>(end(),end());
+    }
+
+    void openid_message_t::reset_fields() {
+        clear();
+    }
+    void openid_message_t::set_field(const string& n,const string& v) {
+        insert(value_type(n,v));
+    }
+    void openid_message_t::reset_field(const string& n) {
+        erase(n);
+    }
+
+}
diff --git a/lib/params.cc b/lib/params.cc
index 7a572c1..6805516 100644
--- a/lib/params.cc
+++ b/lib/params.cc
@@ -1,121 +1,30 @@
 #include <opkele/types.h>
 #include <opkele/exception.h>
 #include <opkele/util.h>
 #include <openssl/sha.h>
 #include <openssl/hmac.h>
 
 #include "config.h"
 
 namespace opkele {
     using namespace std;
 
-    bool params_t::has_param(const string& n) const {
-        return find(n)!=end();
-    }
-    const string& params_t::get_param(const string& n) const {
-        const_iterator i = find(n);
-        if(i==end())
-            throw failed_lookup(OPKELE_CP_ n+": no such parameter");
-        return i->second;
-    }
-    string& params_t::get_param(const string& n) {
-        iterator i = find(n);
-        if(i==end())
-            throw failed_lookup(OPKELE_CP_ n+": no such parameter");
-        return i->second;
-    }
-
-    void params_t::parse_keyvalues(const string& kv) {
-        clear();
-        string::size_type p = 0;
-        while(true) {
-            string::size_type co = kv.find(':',p);
-            if(co==string::npos)
-                break;
-#ifndef POSTELS_LAW
-            string::size_type nl = kv.find('\n',co+1);
-            if(nl==string::npos)
-                throw bad_input(OPKELE_CP_ "malformed input");
-            if(nl>co)
-                insert(value_type(kv.substr(p,co-p),kv.substr(co+1,nl-co-1)));
-            p = nl+1;
-#else /* POSTELS_LAW */
-            string::size_type lb = kv.find_first_of("\r\n",co+1);
-            if(lb==string::npos) {
-                insert(value_type(kv.substr(p,co-p),kv.substr(co+1)));
-                break;
-            }
-            if(lb>co)
-                insert(value_type(kv.substr(p,co-p),kv.substr(co+1,lb-co-1)));
-            string::size_type nolb = kv.find_first_not_of("\r\n",lb);
-            if(nolb==string::npos)
-                break;
-            p = nolb;
-#endif /* POSTELS_LAW */
-        }
-    }
-
-    void params_t::sign(secret_t secret,string& sig,const string& slist,const char *prefix) const {
-        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 += ':';
-            if(prefix) f.insert(0,prefix);
-            kv += get_param(f);
-            kv += '\n';
-            if(co==string::npos)
-                break;
-            p = co+1;
-        }
-        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);
-        sig = util::encode_base64(md,md_len);
-    }
-
     string params_t::append_query(const string& url,const char *prefix) const {
         string rv = url;
         bool p = true;
         if(rv.find('?')==string::npos) {
-            rv += '?';
-            p = false;
-        }
-        for(const_iterator i=begin();i!=end();++i) {
+            rv += '?'; p = false; }
+        for(fields_iterator i=fields_begin();i!=fields_end();++i) {
             if(p)
                 rv += '&';
             else
                 p = true;
-            rv += prefix;
-            rv += i->first;
+            if(prefix) rv += prefix;
+            rv += *i;
             rv += '=';
-            rv += util::url_encode(i->second);
+            rv += util::url_encode(get_field(*i));
         }
         return rv;
     }
 
-    string params_t::query_string(const char *prefix) const {
-        string rv;
-        for(const_iterator i=begin();i!=end();++i) {
-            if(!rv.empty())
-                rv += '&';
-            rv += prefix;
-            rv += i->first;
-            rv += '=';
-            rv += util::url_encode(i->second);
-        }
-        return rv;
-    }
-
-    ostream& operator << (ostream& o,const params_t& p) {
-        for(params_t::const_iterator i=p.begin();i!=p.end();++i)
-            o << i->first << ':' << i->second << '\n';
-        return o;
-    }
-
 }
diff --git a/lib/prequeue_rp.cc b/lib/prequeue_rp.cc
new file mode 100644
index 0000000..e242f87
--- a/dev/null
+++ b/lib/prequeue_rp.cc
@@ -0,0 +1,81 @@
+#include <iostream>
+#include <openssl/sha.h>
+#include <openssl/hmac.h>
+#include <opkele/exception.h>
+#include <opkele/prequeue_rp.h>
+#include <opkele/discovery.h>
+#include <opkele/uris.h>
+#include <opkele/data.h>
+#include <opkele/util.h>
+#include <opkele/curl.h>
+#include <opkele/debug.h>
+
+namespace opkele {
+
+    class __OP_verifier_good_input : public exception {
+        public:
+            __OP_verifier_good_input(OPKELE_E_PARS)
+                : exception(OPKELE_E_CONS) { }
+    };
+
+    class OP_verifier : public iterator<output_iterator_tag,openid_endpoint_t,void> {
+        public:
+            const string& OP;
+            const string& id;
+
+            OP_verifier(const string& o,const string& i)
+                : OP(o), id(i) { }
+
+            OP_verifier& operator*() { return *this; }
+            OP_verifier& operator=(const openid_endpoint_t& oep) {
+                if(oep.uri==OP) {
+                    if(oep.claimed_id==IDURI_SELECT20
+                            || oep.local_id==IDURI_SELECT20 )
+                        throw bad_input(OPKELE_CP_ "claimed_id is an OP-Id");
+                    if(oep.local_id==id)
+                        throw __OP_verifier_good_input(OPKELE_CP_ "Found corresponding endpoint");
+                }
+                return *this;
+            }
+
+            OP_verifier& operator++() { return *this; }
+            OP_verifier& operator++(int) { return *this; }
+    };
+
+    void prequeue_RP::verify_OP(const string& OP,const string& claimed_id,const string& identity) const {
+        try {
+            idiscover(OP_verifier(OP,identity),claimed_id);
+            throw id_res_unauthorized(OPKELE_CP_
+                    "OP is not authorized to make an assertion regarding the identity");
+        }catch(__OP_verifier_good_input& ovgi) {
+        }
+    }
+
+    class endpoint_queuer : public iterator<output_iterator_tag,openid_endpoint_t,void> {
+        public:
+            prequeue_RP& rp;
+
+            endpoint_queuer(prequeue_RP& rp) : rp(rp) { }
+
+            endpoint_queuer& operator*() { return *this; }
+            endpoint_queuer& operator=(const openid_endpoint_t& oep) {
+                rp.queue_endpoint(oep); return *this; }
+
+            endpoint_queuer& operator++() { return *this; }
+            endpoint_queuer& operator++(int) { return *this; }
+    };
+
+    void prequeue_RP::initiate(const string& usi) {
+        begin_queueing();
+        set_normalized_id( idiscover(endpoint_queuer(*this),usi) );
+        end_queueing();
+    }
+
+    void prequeue_RP::set_normalized_id(const string& nid) {
+    }
+
+    const string prequeue_RP::get_normalized_id() const {
+        throw not_implemented(OPKELE_CP_ "get_normalized_id() is not implemented");
+    }
+
+}
diff --git a/lib/server.cc b/lib/server.cc
index 282521e..776f1ae 100644
--- a/lib/server.cc
+++ b/lib/server.cc
@@ -1,171 +1,171 @@
 #include <cstring>
 #include <vector>
 #include <openssl/sha.h>
 #include <openssl/hmac.h>
 #include <opkele/util.h>
 #include <opkele/exception.h>
 #include <opkele/server.h>
 #include <opkele/data.h>
 
 namespace opkele {
     using namespace std;
 
     void server_t::associate(const params_t& pin,params_t& pout) {
         util::dh_t dh;
         util::bignum_t c_pub;
         unsigned char key_sha1[SHA_DIGEST_LENGTH];
         enum {
             sess_cleartext,
             sess_dh_sha1
         } st = sess_cleartext;
         if(
                 pin.has_param("openid.session_type")
                 && pin.get_param("openid.session_type")=="DH-SHA1" ) {
             /* TODO: fallback to cleartext in case of exceptions here? */
             if(!(dh = DH_new()))
                 throw exception_openssl(OPKELE_CP_ "failed to DH_new()");
             c_pub = util::base64_to_bignum(pin.get_param("openid.dh_consumer_public"));
             if(pin.has_param("openid.dh_modulus"))
                 dh->p = util::base64_to_bignum(pin.get_param("openid.dh_modulus"));
             else
                 dh->p = util::dec_to_bignum(data::_default_p);
             if(pin.has_param("openid.dh_gen"))
                 dh->g = util::base64_to_bignum(pin.get_param("openid.dh_gen"));
             else
                 dh->g = util::dec_to_bignum(data::_default_g);
             if(!DH_generate_key(dh))
                 throw exception_openssl(OPKELE_CP_ "failed to DH_generate_key()");
             vector<unsigned char> ck(DH_size(dh)+1);
             unsigned char *ckptr = &(ck.front())+1;
             int cklen = DH_compute_key(ckptr,c_pub,dh);
             if(cklen<0)
                 throw exception_openssl(OPKELE_CP_ "failed to DH_compute_key()");
             if(cklen && (*ckptr)&0x80) {
                 (*(--ckptr)) = 0; ++cklen;
             }
             SHA1(ckptr,cklen,key_sha1);
             st = sess_dh_sha1;
         }
         assoc_t assoc = alloc_assoc(mode_associate);
         time_t now = time(0);
         pout.clear();
         pout["assoc_type"] = assoc->assoc_type();
         pout["assoc_handle"] = assoc->handle();
         /* TODO: eventually remove deprecated stuff */
         pout["issued"] = util::time_to_w3c(now);
         pout["expiry"] = util::time_to_w3c(now+assoc->expires_in());
         pout["expires_in"] = util::long_to_string(assoc->expires_in());
         secret_t secret = assoc->secret();
         switch(st) {
             case sess_dh_sha1:
                 pout["session_type"] = "DH-SHA1";
                 pout["dh_server_public"] = util::bignum_to_base64(dh->pub_key);
                 secret.enxor_to_base64(key_sha1,pout["enc_mac_key"]);
                 break;
             default:
                 secret.to_base64(pout["mac_key"]);
                 break;
         }
     }
 
     void server_t::checkid_immediate(const params_t& pin,string& return_to,params_t& pout,extension_t *ext) {
         checkid_(mode_checkid_immediate,pin,return_to,pout,ext);
     }
 
     void server_t::checkid_setup(const params_t& pin,string& return_to,params_t& pout,extension_t *ext) {
         checkid_(mode_checkid_setup,pin,return_to,pout,ext);
     }
 
     void server_t::checkid_(mode_t mode,const params_t& pin,string& return_to,params_t& pout,extension_t *ext) {
         if(mode!=mode_checkid_immediate && mode!=mode_checkid_setup)
             throw bad_input(OPKELE_CP_ "invalid checkid_* mode");
         pout.clear();
         assoc_t assoc;
         try {
             assoc = retrieve_assoc(pin.get_param("openid.assoc_handle"));
         }catch(failed_lookup& fl) {
             // no handle specified or no valid handle found, going dumb
             assoc = alloc_assoc(mode_checkid_setup);
             if(pin.has_param("openid.assoc_handle"))
                 pout["invalidate_handle"]=pin.get_param("openid.assoc_handle");
         }
         string trust_root;
         try {
             trust_root = pin.get_param("openid.trust_root");
         }catch(failed_lookup& fl) { }
         string identity = pin.get_param("openid.identity");
         return_to = pin.get_param("openid.return_to");
         validate(*assoc,pin,identity,trust_root);
         pout["mode"] = "id_res";
         pout["assoc_handle"] = assoc->handle();
         if(pin.has_param("openid.assoc_handle") && assoc->stateless())
             pout["invalidate_handle"] = pin.get_param("openid.assoc_handle");
         pout["identity"] = identity;
         pout["return_to"] = return_to;
         /* TODO: eventually remove deprecated stuff */
         time_t now = time(0);
         pout["issued"] = util::time_to_w3c(now);
         pout["valid_to"] = util::time_to_w3c(now+120);
         pout["exipres_in"] = "120";
         pout["signed"]="mode,identity,return_to";
         if(ext) ext->checkid_hook(pin,pout);
-        pout.sign(assoc->secret(),pout["sig"],pout["signed"]);
+        pout["sig"] = util::base64_signature(assoc,pout);
     }
 
     void server_t::check_authentication(const params_t& pin,params_t& pout) {
         vector<unsigned char>  sig;
         const string& sigenc = pin.get_param("openid.sig");
         util::decode_base64(sigenc,sig);
         assoc_t assoc;
         try {
             assoc = retrieve_assoc(pin.get_param("openid.assoc_handle"));
         }catch(failed_lookup& fl) {
             throw failed_assertion(OPKELE_CP_ "invalid handle or handle not specified");
         }
         if(!assoc->stateless())
             throw stateful_handle(OPKELE_CP_ "will not do check_authentication on a stateful handle");
         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 += ':';
             if(f=="mode")
                 kv += "id_res";
             else {
                 f.insert(0,"openid.");
                 kv += pin.get_param(f);
             }
             kv += '\n';
             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);
         pout.clear();
         if(sig.size()==md_len && !memcmp(&(sig.front()),md,md_len)) {
             pout["is_valid"]="true";
             pout["lifetime"]="60"; /* TODO: eventually remove deprecated stuff */
         }else{
             pout["is_valid"]="false";
             pout["lifetime"]="0"; /* TODO: eventually remove deprecated stuff */
         }
         if(pin.has_param("openid.invalidate_handle")) {
             string h = pin.get_param("openid.invalidate_handle");
             try {
                 assoc_t tmp = retrieve_assoc(h);
             }catch(invalid_handle& ih) {
                 pout["invalidate_handle"] = h;
             }catch(failed_lookup& fl) { }
         }
     }
 
 }
diff --git a/lib/sreg.cc b/lib/sreg.cc
index 03edf57..7e2d588 100644
--- a/lib/sreg.cc
+++ b/lib/sreg.cc
@@ -1,126 +1,140 @@
 #include <opkele/exception.h>
 #include <opkele/sreg.h>
 #include <opkele/uris.h>
 #include <algorithm>
 
 namespace opkele {
     using std::find;
 
     static const struct _sreg_field {
         const char *fieldname;
         sreg_t::fieldbit_t fieldbit;
             }fields[] = {
         { "nickname", sreg_t::field_nickname },
         { "email", sreg_t::field_email },
         { "fullname", sreg_t::field_fullname },
         { "dob", sreg_t::field_dob },
         { "gender", sreg_t::field_gender },
         { "postcode", sreg_t::field_postcode },
         { "country", sreg_t::field_country },
         { "language", sreg_t::field_language },
         { "timezone", sreg_t::field_timezone }
     };
         #   define fields_BEGINfields
 #   define fields_END &fields[sizeof(fields)/sizeof(*fields)]
     typedef const struct _sreg_field *fields_iterator;
 
     bool operator==(const struct _sreg_field& fd,const string& fn) {
         return fd.fieldname==fn;
     }
 
-    void sreg_t::checkid_hook(params_t& p,const string& /* identity */) {
+    void sreg_t::checkid_hook(basic_openid_message& om) {
         string fr, fo;
         for(fields_iterator f=fields_BEGIN;f<fields_END;++f) {
             if(f->fieldbit&fields_required) {
                 if(!fr.empty()) fr+=",";
                 fr += f->fieldname;
             }
             if(f->fieldbit&fields_optional) {
                 if(!fo.empty()) fo+=",";
                 fo += f->fieldname;
             }
         }
-        p["ns.sreg"] = OIURI_SREG11;
-        if(!fr.empty()) p["sreg.required"]=fr;
-        if(!fo.empty()) p["sreg.optional"]=fo;
-        if(!policy_url.empty()) p["sreg.policy_url"]=policy_url;
+        string pfx = om.allocate_ns(OIURI_SREG11,"sreg");
+        if(!fr.empty()) om.set_field(pfx+".required",fr);
+        if(!fo.empty()) om.set_field(pfx+".optional",fo);
+        if(!policy_url.empty()) om.set_field(pfx+".policy_url",policy_url);
     }
 
-    void sreg_t::id_res_hook(const params_t& /* p */,const params_t& sp,const string& /* identity */) {
+    void sreg_t::id_res_hook(const basic_openid_message& om,const basic_openid_message& sp) {
         clear();
+        string pfx;
+        try {
+            pfx = om.find_ns(OIURI_SREG11,"sreg");
+        }catch(failed_lookup& fl) {
+            try {
+                pfx = om.find_ns(OIURI_SREG10,"sreg");
+            }catch(failed_lookup& fl) {
+                return;
+            }
+        }
+        pfx += '.';
         for(fields_iterator f=fields_BEGIN;f<fields_END;++f) {
-            string fn = "sreg."; fn+=f->fieldname;
-            if(!sp.has_param(fn)) continue;
+            string fn = pfx; fn+=f->fieldname;
+            if(!sp.has_field(fn)) continue;
             has_fields |= f->fieldbit;
-            response[f->fieldbit]=sp.get_param(fn);
+            response[f->fieldbit]=sp.get_field(fn);
         }
     }
 
     const string& sreg_t::get_field(fieldbit_t fb) const {
         response_t::const_iterator i = response.find(fb);
         if(i==response.end())
             throw failed_lookup(OPKELE_CP_ "no field data available");
         return i->second;
     }
 
     void sreg_t::set_field(fieldbit_t fb,const string& fv) {
         response[fb] = fv;
         has_fields |= fb;
     }
 
     void sreg_t::reset_field(fieldbit_t fb) {
         has_fields &= ~fb;
         response.erase(fb);
     }
 
     void sreg_t::clear() {
         has_fields = 0; response.clear();
     }
 
     static long fields_list_to_bitmask(string& fl) {
         long rv = 0;
         while(!fl.empty()) {
             string::size_type co = fl.find(',');
             string fn;
             if(co==string::npos) {
                 fn = fl; fl.erase();
             }else{
                 fn = fl.substr(0,co); fl.erase(0,co+1);
             }
             fields_iterator f = find(fields_BEGIN,fields_END,fn);
             if(f!=fields_END)
                 rv |= f->fieldbit;
         }
         return rv;
     }
 
-    void sreg_t::checkid_hook(const params_t& pin,params_t& pout) {
+    void sreg_t::checkid_hook(const basic_openid_message& inm,basic_openid_message& oum) {
+        string ins = inm.find_ns(OIURI_SREG11,"sreg");
         fields_optional = 0; fields_required = 0; policy_url.erase();
         fields_response = 0;
         try {
-            string fl = pin.get_param("openid.sreg.required");
+            string fl = inm.get_field(ins+".required");
             fields_required = fields_list_to_bitmask(fl);
         }catch(failed_lookup&) { }
         try {
-            string fl = pin.get_param("openid.sreg.optional");
+            string fl = inm.get_field(ins+".optional");
             fields_optional = fields_list_to_bitmask(fl);
         }catch(failed_lookup&) { }
         try {
-            policy_url = pin.get_param("openid.sreg.policy_url");
+            policy_url = inm.get_field(ins+".policy_url");
         }catch(failed_lookup&) { }
-        setup_response(pin,pout);
+        setup_response(inm,oum);
+        string ons = oum.allocate_ns(OIURI_SREG11,"sreg");
         fields_response &= has_fields;
+        string signeds = "ns."+ons;
         for(fields_iterator f=fields_BEGIN;f<fields_END;++f) {
             if(!(f->fieldbit&fields_response)) continue;
-            if(!pout["signed"].empty())
-                pout["signed"] +=',';
-            string pn = "sreg."; pn += f->fieldname;
-            pout["signed"] += pn;
-            pout[pn] = get_field(f->fieldbit);
+            signeds +=',';
+            string pn = ons; pn += '.'; pn += f->fieldname;
+            signeds += pn;
+            oum.set_field(pn,get_field(f->fieldbit));
         }
+        oum.add_to_signed(signeds);
     }
 
-    void sreg_t::setup_response(const params_t& /* pin */,params_t& /* pout */) {
+    void sreg_t::setup_response(const basic_openid_message& /* inm */,basic_openid_message& /* oum */) {
         fields_response = (fields_required|fields_optional)&has_fields;
     }
 }
diff --git a/lib/util.cc b/lib/util.cc
index a9b9bed..54d6535 100644
--- a/lib/util.cc
+++ b/lib/util.cc
@@ -1,316 +1,383 @@
 #include <errno.h>
 #include <cassert>
 #include <cctype>
 #include <cstring>
 #include <vector>
 #include <string>
 #include <stack>
 #include <openssl/bio.h>
 #include <openssl/evp.h>
+#include <openssl/hmac.h>
 #include <curl/curl.h>
 #include "opkele/util.h"
 #include "opkele/exception.h"
 
+#include <config.h>
+#ifdef HAVE_DEMANGLE
+# include <cxxabi.h>
+#endif
+
 namespace opkele {
     using namespace std;
 
     namespace util {
 
         /*
          * base64
          */
         string encode_base64(const void *data,size_t length) {
             BIO *b64 = 0, *bmem = 0;
             try {
                 b64 = BIO_new(BIO_f_base64());
                 if(!b64)
                     throw exception_openssl(OPKELE_CP_ "failed to BIO_new() base64 encoder");
                 BIO_set_flags(b64,BIO_FLAGS_BASE64_NO_NL);
                 bmem = BIO_new(BIO_s_mem());
                 BIO_set_flags(b64,BIO_CLOSE);
                 if(!bmem)
                     throw exception_openssl(OPKELE_CP_ "failed to BIO_new() memory buffer");
                 BIO_push(b64,bmem);
                 if(((size_t)BIO_write(b64,data,length))!=length)
                     throw exception_openssl(OPKELE_CP_ "failed to BIO_write()");
                 if(BIO_flush(b64)!=1)
                     throw exception_openssl(OPKELE_CP_ "failed to BIO_flush()");
                 char *rvd;
                 long rvl = BIO_get_mem_data(bmem,&rvd);
                 string rv(rvd,rvl);
                 BIO_free_all(b64);
                 return rv;
             }catch(...) {
                 if(b64) BIO_free_all(b64);
                 throw;
             }
         }
 
         void decode_base64(const string& data,vector<unsigned char>& rv) {
             BIO *b64 = 0, *bmem = 0;
             rv.clear();
             try {
                 bmem = BIO_new_mem_buf((void*)data.data(),data.size());
                 if(!bmem)
                     throw exception_openssl(OPKELE_CP_ "failed to BIO_new_mem_buf()");
                 b64 = BIO_new(BIO_f_base64());
                 if(!b64)
                     throw exception_openssl(OPKELE_CP_ "failed to BIO_new() base64 decoder");
                 BIO_set_flags(b64,BIO_FLAGS_BASE64_NO_NL);
                 BIO_push(b64,bmem);
                 unsigned char tmp[512];
                 size_t rb = 0;
                 while((rb=BIO_read(b64,tmp,sizeof(tmp)))>0)
                     rv.insert(rv.end(),tmp,&tmp[rb]);
                 BIO_free_all(b64);
             }catch(...) {
                 if(b64) BIO_free_all(b64);
                 throw;
             }
         }
 
         /*
          * big numerics
          */
 
         BIGNUM *base64_to_bignum(const string& b64) {
             vector<unsigned char> bin;
             decode_base64(b64,bin);
             BIGNUM *rv = BN_bin2bn(&(bin.front()),bin.size(),0);
             if(!rv)
                 throw failed_conversion(OPKELE_CP_ "failed to BN_bin2bn()");
             return rv;
         }
 
         BIGNUM *dec_to_bignum(const string& dec) {
             BIGNUM *rv = 0;
             if(!BN_dec2bn(&rv,dec.c_str()))
                 throw failed_conversion(OPKELE_CP_ "failed to BN_dec2bn()");
             return rv;
         }
 
         string bignum_to_base64(const BIGNUM *bn) {
             vector<unsigned char> bin(BN_num_bytes(bn)+1);
             unsigned char *binptr = &(bin.front())+1;
             int l = BN_bn2bin(bn,binptr);
             if(l && (*binptr)&0x80){
                 (*(--binptr)) = 0; ++l;
             }
             return encode_base64(binptr,l);
         }
 
         /*
          * w3c times
          */
 
         string time_to_w3c(time_t t) {
             struct tm tm_t;
             if(!gmtime_r(&t,&tm_t))
                 throw failed_conversion(OPKELE_CP_ "failed to BN_dec2bn()");
             char rv[25];
             if(!strftime(rv,sizeof(rv)-1,"%Y-%m-%dT%H:%M:%SZ",&tm_t))
                 throw failed_conversion(OPKELE_CP_ "failed to strftime()");
             return rv;
         }
 
         time_t w3c_to_time(const string& w) {
             int fraction;
             struct tm tm_t;
             memset(&tm_t,0,sizeof(tm_t));
             if( (
                         sscanf(
                             w.c_str(),
                             "%04d-%02d-%02dT%02d:%02d:%02dZ",
                             &tm_t.tm_year,&tm_t.tm_mon,&tm_t.tm_mday,
                             &tm_t.tm_hour,&tm_t.tm_min,&tm_t.tm_sec
                             ) != 6
                 ) && (
                     sscanf(
                         w.c_str(),
                         "%04d-%02d-%02dT%02d:%02d:%02d.%03dZ",
                         &tm_t.tm_year,&tm_t.tm_mon,&tm_t.tm_mday,
                         &tm_t.tm_hour,&tm_t.tm_min,&tm_t.tm_sec,
                         &fraction
                         ) != 7
                     ) )
                 throw failed_conversion(OPKELE_CP_ "failed to sscanf()");
             tm_t.tm_mon--;
             tm_t.tm_year-=1900;
             time_t rv = mktime(&tm_t);
             if(rv==(time_t)-1)
                 throw failed_conversion(OPKELE_CP_ "failed to mktime()");
             return rv-timezone;
         }
 
         /*
          *
          */
 
         string url_encode(const string& str) {
             char * t = curl_escape(str.c_str(),str.length());
             if(!t)
                 throw failed_conversion(OPKELE_CP_ "failed to curl_escape()");
             string rv(t);
             curl_free(t);
             return rv;
         }
 
         string long_to_string(long l) {
             char rv[32];
             int r=snprintf(rv,sizeof(rv),"%ld",l);
             if(r<0 || r>=(int)sizeof(rv))
                 throw failed_conversion(OPKELE_CP_ "failed to snprintf()");
             return rv;
         }
 
         long string_to_long(const string& s) {
             char *endptr = 0;
             long rv = strtol(s.c_str(),&endptr,10);
             if((!endptr) || endptr==s.c_str())
                 throw failed_conversion(OPKELE_CP_ "failed to strtol()");
             return rv;
         }
 
         /*
          * Normalize URL according to the rules, described in rfc 3986, section 6
          *
          * - uppercase hex triplets (e.g. %ab -> %AB)
          * - lowercase scheme and host
          * - decode %-encoded characters, specified as unreserved in rfc 3986, section 2.3,
          *   that is - [:alpha:][:digit:]._~-
          * - remove dot segments
          * - remove empty and default ports
          * - if there's no path component, add '/'
          */
          string rfc_3986_normalize_uri(const string& uri) {
              static const char *whitespace = " \t\r\n";
              string rv;
              string::size_type ns = uri.find_first_not_of(whitespace);
              if(ns==string::npos)
                  throw bad_input(OPKELE_CP_ "Can't normalize empty URI");
              string::size_type colon = uri.find(':',ns);
              if(colon==string::npos)
                  throw bad_input(OPKELE_CP_ "No scheme specified in URI");
              transform(
                      uri.begin()+ns, uri.begin()+colon+1,
                      back_inserter(rv), ::tolower );
              bool s;
              string::size_type ul = uri.find_last_not_of(whitespace)+1;
              if(ul <= (colon+3))
                  throw bad_input(OPKELE_CP_ "Unexpected end of URI being normalized encountered");
              if(uri[colon+1]!='/' || uri[colon+2]!='/')
                  throw bad_input(OPKELE_CP_ "Unexpected input in URI being normalized after scheme component");
              if(rv=="http:")
                  s = false;
              else if(rv=="https:")
                  s = true;
              else{
-                 /* TODO: support more schemes.
-                  * e.g. xri. How do we normalize
+                 /* TODO: support more schemes.  e.g. xri. How do we normalize
                   * xri?
                   */
                  rv.append(uri,colon+1,ul-colon-1);
                  return rv;
              }
              rv += "//";
              string::size_type interesting = uri.find_first_of(":/#?",colon+3);
              if(interesting==string::npos) {
                  transform(
                          uri.begin()+colon+3,uri.begin()+ul,
                          back_inserter(rv), ::tolower );
                  rv += '/'; return rv;
              }
              transform(
                      uri.begin()+colon+3,uri.begin()+interesting,
                      back_inserter(rv), ::tolower );
              bool qf = false;
              char ic = uri[interesting];
              if(ic==':') {
                  string::size_type ni = uri.find_first_of("/#?%",interesting+1);
                  const char *nptr = uri.data()+interesting+1;
                  char *eptr = 0;
                  long port = strtol(nptr,&eptr,10);
                  if( (port>0) && (port<65535) && port!=(s?443:80) ) {
                      char tmp[8];
                      snprintf(tmp,sizeof(tmp),":%ld",port);
                      rv += tmp;
                  }
                  if(ni==string::npos) {
                      rv += '/'; return rv;
                  }
                  interesting = ni;
              }else if(ic!='/') {
                  rv += '/'; rv += ic;
                  qf = true;
                  ++interesting;
              }
              string::size_type n = interesting;
              char tmp[3] = { 0,0,0 };
              stack<string::size_type> psegs; psegs.push(rv.length());
              string pseg;
              for(;n<ul;) {
                  string::size_type unsafe = uri.find_first_of(qf?"%":"%/?#",n);
                  if(unsafe==string::npos) {
                      pseg.append(uri,n,ul-n-1); n = ul-1;
                  }else{
                      pseg.append(uri,n,unsafe-n);
                      n = unsafe;
                  }
                  char c = uri[n++];
                  if(c=='%') {
                      if((n+1)>=ul)
                          throw bad_input(OPKELE_CP_ "Unexpected end of URI encountered while parsing percent-encoded character");
                      tmp[0] = uri[n++];
                      tmp[1] = uri[n++];
                      if(!( isxdigit(tmp[0]) && isxdigit(tmp[1]) ))
                          throw bad_input(OPKELE_CP_ "Invalid percent-encoded character in URI being normalized");
                      int cc = strtol(tmp,0,16);
                      if( isalpha(cc) || isdigit(cc) || strchr("._~-",cc) )
                          pseg += cc;
                      else{
                          pseg += '%';
                          pseg += toupper(tmp[0]); pseg += toupper(tmp[1]);
                      }
                  }else if(qf) {
                      rv += pseg; rv += c;
                      pseg.clear();
                  }else if(n>=ul || strchr("?/#",c)) {
                      if(pseg.empty() || pseg==".") {
                      }else if(pseg=="..") {
                          if(psegs.size()>1) {
                              rv.resize(psegs.top()); psegs.pop();
                          }
                      }else{
                          psegs.push(rv.length());
                          if(c!='/') {
                              pseg += c;
                              qf = true;
                          }
                          rv += '/'; rv += pseg;
                      }
                      if(c=='/' && (n>=ul || strchr("?#",uri[n])) ) {
                          rv += '/';
                          if(n<ul)
                              qf = true;
                      }else if(strchr("?#",c)) {
                          if(psegs.size()==1 && psegs.top()==rv.length())
                              rv += '/';
                          if(pseg.empty())
                              rv += c;
                          qf = true;
                      }
                      pseg.clear();
                  }else{
                      pseg += c;
                  }
              }
              if(!pseg.empty()) {
                  if(!qf) rv += '/';
                  rv += pseg;
              }
              return rv;
          }
 
+        string& strip_uri_fragment_part(string& u) {
+            string::size_type q = u.find('?'), f = u.find('#');
+            if(q==string::npos) {
+                if(f!=string::npos)
+                    u.erase(f);
+            }else{
+                if(f!=string::npos) {
+                    if(f<q)
+                        u.erase(f,q-f);
+                    else
+                        u.erase(f);
+                }
+            }
+            return u;
+        }
+
+        string abi_demangle(const char *mn) {
+#ifndef HAVE_DEMANGLE
+            return mn;
+#else /* !HAVE_DEMANGLE */
+            int dstat;
+            char *demangled = abi::__cxa_demangle(mn,0,0,&dstat);
+            if(dstat)
+                return mn;
+            string rv = demangled;
+            free(demangled);
+            return rv;
+#endif /* !HAVE_DEMANGLE */
+        }
+
+        string base64_signature(const assoc_t& assoc,const basic_openid_message& om) {
+            const string& slist = om.get_field("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 += ':';
+                kv += om.get_field(f);
+                kv += '\n';
+                if(co==string::npos) break;
+                p = co+1;
+            }
+            const secret_t& secret = assoc->secret();
+            const EVP_MD *evpmd;
+            const string& at = assoc->assoc_type();
+            if(at=="HMAC-SHA256")
+                evpmd = EVP_sha256();
+            else if(at=="HMAC-SHA1")
+                evpmd = EVP_sha1();
+            else
+                throw unsupported(OPKELE_CP_ "unknown association type");
+            unsigned int md_len = 0;
+            unsigned char *md = HMAC(evpmd,
+                    &(secret.front()),secret.size(),
+                    (const unsigned char*)kv.data(),kv.length(),
+                    0,&md_len);
+            return encode_base64(md,md_len);
+        }
+
     }
 
 }