the whole library rewritten

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

12 files changed, 868 insertions, 164 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
@@ -1,395 +1,395 @@
 #include <algorithm>
 #include <cassert>
 #include <cstring>
 #include <opkele/util.h>
 #include <opkele/curl.h>
 #include <opkele/exception.h>
 #include <opkele/data.h>
 #include <opkele/consumer.h>
 #include <openssl/sha.h>
 #include <openssl/hmac.h>
 #include <iostream>
 
 #include "config.h"
 
 #include <pcre.h>
 
 namespace opkele {
     using namespace std;
     using util::curl_t;
     using util::curl_pick_t;
 
     class pcre_matches_t {
 	public:
 	    int *_ov;
 	    int _s;
 
 	    pcre_matches_t() : _ov(0), _s(0) { }
 	    pcre_matches_t(int s) : _ov(0), _s(s) {
 		if(_s&1) ++_s;
 		_s += _s>>1;
 		_ov = new int[_s];
 	    }
 	    ~pcre_matches_t() throw() { if(_ov) delete[] _ov; }
 
 	    int begin(int i) const { return _ov[i<<1]; }
 	    int end(int i) const { return _ov[(i<<1)+1]; }
 	    int length(int i) const { int t=i<<1; return _ov[t+1]-_ov[t]; }
     };
 
     class pcre_t {
 	public:
 	    pcre *_p;
 
 	    pcre_t() : _p(0) { }
 	    pcre_t(pcre *p) : _p(p) { }
 	    pcre_t(const char *re,int opts) : _p(0) {
 		static const char *errptr; static int erroffset;
 		_p = pcre_compile(re,opts,&errptr,&erroffset,NULL);
 		if(!_p)
 		    throw internal_error(OPKELE_CP_ string("Failed to compile regexp: ")+errptr);
 	    }
 	    ~pcre_t() throw() { if(_p) (*pcre_free)(_p); }
 
 	    pcre_t& operator=(pcre *p) { if(_p) (*pcre_free)(_p); _p=p; return *this; }
 
 	    operator const pcre*(void) const { return _p; }
 	    operator pcre*(void) { return _p; }
 
 	    int exec(const string& s,pcre_matches_t& m) {
 		if(!_p)
 		    throw internal_error(OPKELE_CP_ "Trying to execute absent regexp");
 		return pcre_exec(_p,NULL,s.c_str(),s.length(),0,0,m._ov,m._s);
 	    }
     };
 
     assoc_t consumer_t::associate(const string& server) {
 	util::dh_t dh = DH_new();
 	if(!dh)
 	    throw exception_openssl(OPKELE_CP_ "failed to DH_new()");
 	dh->p = util::dec_to_bignum(data::_default_p);
 	dh->g = util::dec_to_bignum(data::_default_g);
 	if(!DH_generate_key(dh))
 	    throw exception_openssl(OPKELE_CP_ "failed to DH_generate_key()");
 	string request = 
 	    "openid.mode=associate"
 	    "&openid.assoc_type=HMAC-SHA1"
 	    "&openid.session_type=DH-SHA1"
 	    "&openid.dh_consumer_public=";
 	request += util::url_encode(util::bignum_to_base64(dh->pub_key));
 	curl_pick_t curl = curl_pick_t::easy_init();
 	if(!curl)
 	    throw exception_curl(OPKELE_CP_ "failed to initialize curl");
 	CURLcode r;
 	(r=curl.misc_sets())
 	|| (r=curl.easy_setopt(CURLOPT_URL,server.c_str()))
 	|| (r=curl.easy_setopt(CURLOPT_POST,1))
 	|| (r=curl.easy_setopt(CURLOPT_POSTFIELDS,request.data()))
 	|| (r=curl.easy_setopt(CURLOPT_POSTFIELDSIZE,request.length()))
 	|| (r=curl.set_write())
 	;
 	if(r)
 	    throw exception_curl(OPKELE_CP_ "failed to set curly options",r);
 	if( (r=curl.easy_perform()) )
 	    throw exception_curl(OPKELE_CP_ "failed to perform curly request",r);
 	params_t p; p.parse_keyvalues(curl.response);
 	if(p.has_param("assoc_type") && p.get_param("assoc_type")!="HMAC-SHA1")
 	    throw bad_input(OPKELE_CP_ "unsupported assoc_type");
 	string st;
 	if(p.has_param("session_type")) st = p.get_param("session_type");
 	if((!st.empty()) && st!="DH-SHA1")
 	    throw bad_input(OPKELE_CP_ "unsupported session_type");
 	secret_t secret;
 	if(st.empty()) {
 	    secret.from_base64(p.get_param("mac_key"));
 	}else{
 	    util::bignum_t s_pub = util::base64_to_bignum(p.get_param("dh_server_public"));
 	    vector<unsigned char> ck(DH_size(dh)+1);
 	    unsigned char *ckptr = &(ck.front())+1;
 	    int cklen = DH_compute_key(ckptr,s_pub,dh);
 	    if(cklen<0)
 		throw exception_openssl(OPKELE_CP_ "failed to DH_compute_key()");
 	    if(cklen && (*ckptr)&0x80) {
 		(*(--ckptr)) = 0; ++cklen;
 	    }
 	    unsigned char key_sha1[SHA_DIGEST_LENGTH];
 	    SHA1(ckptr,cklen,key_sha1);
 	    secret.enxor_from_base64(key_sha1,p.get_param("enc_mac_key"));
 	}
 	int expires_in = 0;
 	if(p.has_param("expires_in")) {
 	    expires_in = util::string_to_long(p.get_param("expires_in"));
 	}else if(p.has_param("issued") && p.has_param("expiry")) {
 	    expires_in = util::w3c_to_time(p.get_param("expiry"))-util::w3c_to_time(p.get_param("issued"));
 	}else
 	    throw bad_input(OPKELE_CP_ "no expiration information");
 	return store_assoc(server,p.get_param("assoc_handle"),secret,expires_in);
     }
 
     string consumer_t::checkid_immediate(const string& identity,const string& return_to,const string& trust_root,extension_t *ext) {
 	return checkid_(mode_checkid_immediate,identity,return_to,trust_root,ext);
     }
     string consumer_t::checkid_setup(const string& identity,const string& return_to,const string& trust_root,extension_t *ext) {
 	return checkid_(mode_checkid_setup,identity,return_to,trust_root,ext);
     }
     string consumer_t::checkid_(mode_t mode,const string& identity,const string& return_to,const string& trust_root,extension_t *ext) {
 	params_t p;
 	if(mode==mode_checkid_immediate)
 	    p["mode"]="checkid_immediate";
 	else if(mode==mode_checkid_setup)
 	    p["mode"]="checkid_setup";
 	else
 	    throw bad_input(OPKELE_CP_ "unknown checkid_* mode");
 	string iurl = canonicalize(identity);
 	string server, delegate;
 	retrieve_links(iurl,server,delegate);
 	p["identity"] = delegate.empty()?iurl:delegate;
 	if(!trust_root.empty())
 	    p["trust_root"] = trust_root;
 	p["return_to"] = return_to;
 	try {
 	    string ah = find_assoc(server)->handle();
 	    p["assoc_handle"] = ah;
 	}catch(failed_lookup& fl) {
 	    string ah = associate(server)->handle();
 	    p["assoc_handle"] = ah;
 	}
-	if(ext) ext->checkid_hook(p,identity);
+	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?
 	    rv.insert(0,"http://");
 	    i = sizeof("http://")-1;
 	}else{
 	    i += sizeof("://")-1;
 	}
 	string::size_type qm = rv.find('?',i);
 	string::size_type sl = rv.find('/',i);
 	if(qm!=string::npos) {
 	    if(sl==string::npos || sl>qm)
 		rv.insert(qm,1,'/');
 	}else{
 	    if(sl==string::npos)
 		rv += '/';
 	}
 	return rv;
     }
 
     string consumer_t::canonicalize(const string& url) {
 	string rv = normalize(url);
 	curl_t curl = curl_t::easy_init();
 	if(!curl)
 	    throw exception_curl(OPKELE_CP_ "failed to initialize curl()");
 	string html;
 	CURLcode r;
 	(r=curl.misc_sets())
 	|| (r=curl.easy_setopt(CURLOPT_URL,rv.c_str()))
 	|| (r=curl.easy_setopt(CURLOPT_NOBODY,1))
 	;
 	if(r)
 	    throw exception_curl(OPKELE_CP_ "failed to set curly options",r);
 	r = curl.easy_perform();
 	if(r)
 	    throw exception_curl(OPKELE_CP_ "failed to perform curly request",r);
 	const char *eu = 0;
 	r = curl.easy_getinfo(CURLINFO_EFFECTIVE_URL,&eu);
 	if(r)
 	    throw exception_curl(OPKELE_CP_ "failed to get CURLINFO_EFFECTIVE_URL",r);
 	rv = eu;
 	return normalize(rv);
     }
 
 }
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,
+		    /* 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_r=application/xrd+xml;sep=false", xmode_xrd);
+				    "?_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",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;
+					"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;
-	    rv += '=';
-	    rv += util::url_encode(i->second);
-	}
-	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;
+	    if(prefix) rv += prefix;
+	    rv += *i;
 	    rv += '=';
-	    rv += util::url_encode(i->second);
+	    rv += util::url_encode(get_field(*i));
 	}
 	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_BEGIN	fields
 #   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);
+	}
+
     }
 
 }