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
@@ -3,7 +3,7 @@ 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} \
@@ -26,6 +26,9 @@ libopkele_la_SOURCES = \
                        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
@@ -154,7 +154,7 @@ namespace opkele {
             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);
     }
 
@@ -222,7 +222,7 @@ namespace opkele {
                 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) {
diff --git a/lib/discovery.cc b/lib/discovery.cc
index d868308..93409f4 100644
--- a/lib/discovery.cc
+++ b/lib/discovery.cc
@@ -18,10 +18,27 @@ namespace opkele {
     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);
     }
@@ -48,7 +65,7 @@ namespace opkele {
             string xri_proxy;
 
             enum {
-                xmode_html = 1, xmode_xrd = 2
+                xmode_html = 1, xmode_xrd = 2, xmode_cid = 4
             };
             int xmode;
 
@@ -84,11 +101,12 @@ namespace opkele {
                 }
             ~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))
@@ -96,22 +114,51 @@ namespace opkele {
                 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('#');
@@ -122,24 +169,33 @@ namespace opkele {
                         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);
@@ -152,7 +208,7 @@ namespace opkele {
                     save_html.clear();
                     save_html.reserve(max_html);
                 }
-                xrd = &result.xrd;
+                xrd = &idis.xrd;
 
                 r = easy_perform();
                 if(r && r!=CURLE_WRITE_ERROR)
@@ -199,17 +255,21 @@ namespace opkele {
                 }
 
                 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]);
                 }
             }
 
@@ -310,7 +370,8 @@ namespace opkele {
                                         pt_stack.push_back(n);
                                         break;
                                     }
-                                }
+                                }else
+                                    ++a;
                             }
                         }else if(is_qelement(n,NSURI_XRD "\tExpires")) {
                             assert(xrd);
@@ -436,11 +497,41 @@ namespace opkele {
                 }
             }
 
+            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
@@ -3,13 +3,13 @@
 
 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
@@ -3,14 +3,14 @@
 
 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
@@ -9,113 +9,22 @@
 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
@@ -109,7 +109,7 @@ namespace opkele {
         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) {
diff --git a/lib/sreg.cc b/lib/sreg.cc
index 03edf57..7e2d588 100644
--- a/lib/sreg.cc
+++ b/lib/sreg.cc
@@ -28,7 +28,7 @@ namespace opkele {
         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) {
@@ -40,19 +40,30 @@ namespace opkele {
                 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);
         }
     }
 
@@ -94,33 +105,36 @@ namespace opkele {
         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
@@ -7,10 +7,16 @@
 #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;
 
@@ -205,8 +211,7 @@ namespace opkele {
              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);
@@ -311,6 +316,68 @@ namespace opkele {
              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);
+        }
+
     }
 
 }