the whole library rewritten

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

22 files changed, 1362 insertions, 295 deletions

diff --git a/include/Makefile.am b/include/Makefile.am
index 51dcea1..50fcb62 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -1,21 +1,32 @@
-nobase_include_HEADERS = \
+NODIST_HEADERS_ = \
 	opkele/acconfig.h \
+	opkele/tr1-mem.h
+
+nobase_include_HEADERS = \
 	opkele/opkele-config.h \
 	opkele/types.h \
 	opkele/association.h \
 	opkele/exception.h \
 	opkele/server.h \
 	opkele/consumer.h \
 	opkele/extension.h \
 	opkele/sreg.h \
 	opkele/extension_chain.h \
 	opkele/xconsumer.h \
 	opkele/xserver.h \
-	opkele/discovery.h \
 	opkele/uris.h \
-	opkele/tr1-mem.h
-EXTRA_DIST = \
+	opkele/tr1-mem.h \
+	opkele/basic_rp.h \
+	opkele/prequeue_rp.h \
+	opkele/iterator.h \
+	${NODIST_HEADERS_}
+
+noinst_HEADERS = \
 	opkele/data.h \
 	opkele/curl.h opkele/expat.h opkele/tidy.h \
 	opkele/util.h \
-	opkele/debug.h
+	opkele/debug.h \
+	opkele/discovery.h
+
+dist-hook:
+	rm -f $(addprefix ${distdir}/,${NODIST_HEADERS_})
diff --git a/include/opkele/basic_rp.h b/include/opkele/basic_rp.h
new file mode 100644
index 0000000..3f17fd9
--- a/dev/null
+++ b/include/opkele/basic_rp.h
@@ -0,0 +1,218 @@
+#ifndef __OPKELE_BASIC_RP_H
+#define __OPKELE_BASIC_RP_H
+
+#include <cstring>
+#include <string>
+#include <opkele/types.h>
+#include <opkele/extension.h>
+
+namespace opkele {
+    using std::string;
+
+    struct openid_endpoint_t {
+	string uri;
+	string claimed_id;
+	string local_id;
+
+	openid_endpoint_t() { }
+	openid_endpoint_t(const string& u,const string& cid,const string& lid)
+	    : uri(u), claimed_id(cid), local_id(lid) { }
+
+	bool operator==(const openid_endpoint_t& x) const {
+	    return uri==x.uri && local_id==x.local_id; }
+	bool operator<(const openid_endpoint_t& x) const {
+	    int c;
+	    return (c=strcmp(uri.c_str(),x.uri.c_str()))
+		? (c<0) : (strcmp(local_id.c_str(),x.local_id.c_str())<0); }
+    };
+
+    class basic_RP {
+	public:
+
+	    virtual ~basic_RP() { }
+
+	    /**
+	     * @name Global persistent store API
+	     * These are functions related to the associations with OP storage
+	     * and retrieval and nonce records. They provide an interface to
+	     * the persistent storage which is shared by all sessions. If the
+	     * implementor prefers the dumb mode instead, the function should
+	     * throw dumb_RP exception instead.
+	     * @see opkele::dumb_RP
+	     * @{
+	     */
+	    /**
+	     * Store association and return allocated association object.
+	     * @param OP OP endpoint
+	     * @param handle association handle
+	     * @param type association type
+	     * @param secret association secret
+	     * @params expires_in the number of seconds association expires in
+	     * @return the association object
+	     * @throw dumb_RP for dumb RP
+	     */
+	    virtual assoc_t store_assoc(
+		    const string& OP,const string& handle,
+		    const string& type,const secret_t& secret,
+		    int expires_in) = 0;
+	    /**
+	     * Find valid unexpired association with an OP.
+	     * @param OP OP endpoint URL
+	     * @return association found
+	     * @throw failed_lookup if no association found
+	     * @throw dumb_RP for dumb RP
+	     */
+	    virtual assoc_t find_assoc(
+		    const string& OP) = 0;
+	    /**
+	     * Retrieve valid association handle for an OP by handle.
+	     * @param OP OP endpoint URL
+	     * @param handle association handle
+	     * @return association found
+	     * @throw failed_lookup if no association found
+	     * @throw dumb_RP for dumb RP
+	     */
+	    virtual assoc_t retrieve_assoc(
+		    const string& OP,const string& handle) = 0;
+	    /**
+	     * Invalidate association with OP
+	     * @param OP OP endpoint URL
+	     * @param handle association handle
+	     * @throw dumb_RP for dumb RP
+	     */
+	    virtual void invalidate_assoc(const string& OP,const string& handle) = 0;
+
+	    /**
+	     * Check the nonce validity. That is, check that we haven't
+	     * accepted request with this nonce from this OP, yet. May involve
+	     * cutting off by the timestamp and checking the rest against the
+	     * store of seen nonces.
+	     * @param OP OP endpoint URL
+	     * @param nonce nonce value
+	     * @throw id_res_bad_nonce if the nonce is not to be accepted, i.e.
+	     * either too old or seen.
+	     */
+	    virtual void check_nonce(const string& OP,const string& nonce) = 0;
+	    /**
+	     * @}
+	     */
+
+	    /**
+	     * @name Session persistent store API
+	     * @{
+	     */
+	    /**
+	     * Retrieve OpenID endpoint being currently used for
+	     * authentication. If there is no endpoint available, throw a
+	     * no_endpoint exception.
+	     * @return reference to the service endpoint object
+	     * @see next_endpoint
+	     * @throw no_endpoint if no endpoint available
+	     */
+	    virtual const openid_endpoint_t& get_endpoint() const = 0;
+	    /**
+	     * Advance to the next endpoint to try.
+	     * @see get_endpoint()
+	     * @throw no_endpoint if there are no more endpoints
+	     */
+	    virtual void next_endpoint() = 0;
+	    /**
+	     * @}
+	     */
+
+	    /**
+	     * @name Site particulars API
+	     * @{
+	     */
+	    /**
+	     * Return an absolute URL of the page being processed, includining
+	     * query parameters. It is used to validate return_to URL on
+	     * positive assertions.
+	     * @return fully qualified url of the page being processed.
+	     */
+	    virtual const string get_this_url() const = 0;
+	    /**
+	     * @}
+	     */
+
+	    /**
+	     * @name OpenID actions
+	     * @{
+	     */
+	    /**
+	     * Initiates authentication session, doing discovery, normalization
+	     * and whatever implementor wants to do at this point.
+	     * @param usi User-supplied identity
+	     */
+	    virtual void initiate(const string& usi) = 0;
+	    /**
+	     * Prepare checkid_request.
+	     * @param rv reference to the openid message to prepare
+	     * @param mode checkid_setup or checkid_immediate
+	     * @param return_to the URL OP should redirect to after completion
+	     * @param realm authentication realm to pass to OP
+	     * @param ext pointer to extension to use in request preparation
+	     * @return reference to the openid message
+	     */
+	    basic_openid_message& checkid_(
+		    basic_openid_message& rv,
+		    mode_t mode,
+		    const string& return_to,const string& realm,
+		    extension_t *ext=0);
+	    /**
+	     * Verify assertion at the end of round-trip.
+	     * @param om incoming openid message
+	     * @param ext pointer to extention to use in parsing assertion
+	     * @throw id_res_setup if checkid_immediate request could not be
+	     * completed
+	     * @throw id_res_cancel if authentication request was canceled
+	     * @throw id_res_mismatch in case of signature mismatch
+	     * @throw id_res_bad_return_to if return_to url seems to be
+	     * tampered with
+	     * @throw id_res_unauthorized if OP is not authorized to make
+	     * assertions regarding the identity
+	     */
+	    void id_res(const basic_openid_message& om,extension_t *ext=0);
+
+	    /**
+	     * Establish association with OP
+	     * @param OP OP to establish association with
+	     * @throw dumb_RP if for a dumb RP
+	     */
+	    virtual assoc_t associate(const string& OP);
+	    /**
+	     * Check authentication with OP and invalidate handle if requested
+	     * and confirmed
+	     * @param OP OP to check with
+	     * @param om message to check
+	     * @throw failed_check_authentication if OP fails to confirm
+	     * authenticity of the assertion
+	     */
+	    void check_authentication(const string& OP,const basic_openid_message& om);
+	    /**
+	     * @}
+	     */
+
+	    /**
+	     * @name Miscellanea
+	     * @{
+	     */
+	    /**
+	     * Verify OP authority. Return normally if OP is authorized to make
+	     * an assertion, throw an exception otherwise.
+	     * @param OP OP endpoint
+	     * @param claimed_id claimed identity
+	     * @param identity OP-Local identifier
+	     * @throw id_res_unauthorized if OP is not authorized to make
+	     * assertion regarding this identity.
+	     */
+	    virtual void verify_OP(const string& OP,
+		    const string& claimed_id,const string& identity) const = 0;
+	    /**
+	     * @}
+	     */
+    };
+
+}
+
+#endif /* __OPKELE_BASIC_RP_H */
diff --git a/include/opkele/discovery.h b/include/opkele/discovery.h
index af4aa29..ab4b9d9 100644
--- a/include/opkele/discovery.h
+++ b/include/opkele/discovery.h
@@ -1,40 +1,104 @@
 #ifndef __OPKELE_DISCOVERY_H
 #define __OPKELE_DISCOVERY_H
 
 #include <string>
 #include <opkele/types.h>
+#include <opkele/basic_rp.h>
 
 namespace opkele {
     using std::string;
 
-    struct idiscovery_t;
+    namespace xrd {
 
-    void idiscover(idiscovery_t& result,const string& identity);
+	struct priority_compare {
+	    inline bool operator()(long a,long b) const {
+		return (a<0) ? false : (b<0) ? true : (a<b);
+	    }
+	};
+
+	template <typename _DT>
+	    class priority_map : public multimap<long,_DT,priority_compare> {
+		typedef multimap<long,_DT,priority_compare> map_type;
+		public:
+
+		    inline _DT& add(long priority,const _DT& d) {
+			return insert(typename map_type::value_type(priority,d))->second;
+		    }
+
+		    bool has_value(const _DT& d) const {
+			for(typename map_type::const_iterator i=this->begin();i!=this->end();++i)
+			    if(i->second==d) return true;
+			return false;
+		    }
+	    };
+
+	typedef priority_map<string> canonical_ids_t;
+	typedef priority_map<string> local_ids_t;
+	typedef set<string> types_t;
+	typedef priority_map<string> uris_t;
+
+	class service_t {
+	    public:
+		types_t types;
+		uris_t uris;
+		local_ids_t local_ids;
+		string provider_id;
+
+		void clear() {
+		    types.clear();
+		    uris.clear(); local_ids.clear();
+		    provider_id.clear();
+		}
+	};
+	typedef priority_map<service_t> services_t;
+
+	class XRD_t {
+	    public:
+		time_t expires;
+
+		canonical_ids_t canonical_ids;
+		local_ids_t local_ids;
+		services_t services;
+		string provider_id;
+
+		void clear() {
+		    expires = 0;
+		    canonical_ids.clear(); local_ids.clear();
+		    services.clear();
+		    provider_id.clear();
+		}
+		bool empty() const {
+		    return
+			canonical_ids.empty()
+			&& local_ids.empty()
+			&& services.empty();
+		}
+
+	};
+
+    }
+
+    typedef util::output_iterator_proxy<openid_endpoint_t>
+	endpoint_discovery_iterator;
+
+    string idiscover(
+	    endpoint_discovery_iterator oi,
+	    const string& identity);
 
     struct idiscovery_t {
 	bool xri_identity;
 	string normalized_id;
 	string canonicalized_id;
 	xrd::XRD_t xrd;
 
 	idiscovery_t() { }
-	idiscovery_t(const string& i) {
-	    idiscover(*this,i);
-	}
-	idiscovery_t(const char *i) {
-	    idiscover(*this,i);
-	}
 
 	void clear() {
 	    normalized_id.clear(); canonicalized_id.clear();
 	    xrd.clear();
 	}
 
-	idiscovery_t& operator=(const string& i) {
-	    idiscover(*this,i); return *this; }
-	idiscovery_t& operator=(const char *i) {
-	    idiscover(*this,i); return *this; }
     };
 }
 
 #endif /* __OPKELE_DISCOVERY_H */
diff --git a/include/opkele/exception.h b/include/opkele/exception.h
index a8c3339..ccb39d9 100644
--- a/include/opkele/exception.h
+++ b/include/opkele/exception.h
@@ -302,15 +302,34 @@ namespace opkele {
     };
 
     /**
      * thrown in case of unsupported parameter encountered (e.g. unsupported
      * association type).
      */
     class unsupported : public exception {
 	public:
 	    unsupported(OPKELE_E_PARS)
 		: exception(OPKELE_E_CONS) { }
     };
 
+    /**
+     * thrown by associations store related functions in case of dumb RP.
+     */
+    class dumb_RP : public exception {
+	public:
+	    dumb_RP(OPKELE_E_PARS)
+		: exception(OPKELE_E_CONS) { }
+    };
+
+    /**
+     * thrown by endpoint-queue related function if endpoint is being
+     * accessed but there's no endpoint available.
+     */
+    class no_endpoint : public exception {
+	public:
+	    no_endpoint(OPKELE_E_PARS)
+		: exception(OPKELE_E_CONS) { }
+    };
+
 }
 
 #endif /* __OPKELE_EXCEPTION_H */
diff --git a/include/opkele/extension.h b/include/opkele/extension.h
index 513672f..3ee25ee 100644
--- a/include/opkele/extension.h
+++ b/include/opkele/extension.h
@@ -8,58 +8,59 @@
 
 #include <opkele/types.h>
 
 namespace opkele {
 
     /**
      * OpenID extension hooks base class
      */
     class extension_t {
 	public:
 
 	    virtual ~extension_t() { }
+
 	    /**
 	     * hook called by consumer before submitting data to OpenID server.
 	     * It is supposed to manipulate parameters list.
 	     * @param p parameters about to be submitted to server
 	     * @param identity identity being verified. It may differ from the
 	     * one available in parameters list in case of delegation
 	     * @see consumer_t::checkid_
 	     * @see consumer_t::checkid_immediate
 	     * @see consumer_t::checkid_setup
 	     */
-	    virtual void checkid_hook(params_t& p,const string& identity);
+	    virtual void checkid_hook(basic_openid_message& om);
 	    /**
 	     * hook called by consumer after identity information received from
 	     * OpenID server is verified.
 	     * @param p parameters received from server
 	     * @param sp signed parameters received from server with 'openid.'
 	     * leader stripped
 	     * @param identity identity confirmed. May differ from the one
 	     * available in parameters list in case of delegation. May also be
 	     * empty which means - extract one from parameters
 	     * @see consumer_t::id_res
 	     */
-	    virtual void id_res_hook(const params_t& p,const params_t& sp,const string& identity);
+	    virtual void id_res_hook(const basic_openid_message& om,const basic_openid_message& sp);
 
 	    /**
 	     * hook called by server before returning information to consumer.
 	     * The hook may manipulate output parameters. It is important to
 	     * note that modified pout["signed"] is used for signing response.
 	     * @param pin request parameters list with "openid." prefix
 	     * @param pout response parameters list without "openid." prefix
 	     * @see server_t::checkid_
 	     * @see server_t::checkid_immediate
 	     * @see server_t::checkid_setup
 	     */
-	    virtual void checkid_hook(const params_t& pin,params_t& pout);
+	    virtual void checkid_hook(const basic_openid_message& inm,basic_openid_message& oum);
 
 	    /**
 	     * Casts the object to pointer to itself. For convenient passing
 	     * of pointer.
 	     */
 	    operator extension_t*(void) { return this; }
     };
 
 }
 
 #endif /* __OPKELE_EXTENSION_H */
diff --git a/include/opkele/extension_chain.h b/include/opkele/extension_chain.h
index f0eea94..fb9bc84 100644
--- a/include/opkele/extension_chain.h
+++ b/include/opkele/extension_chain.h
@@ -19,20 +19,20 @@ namespace opkele {
     class extension_chain_t : public extension_t, public list<extension_t*> {
 	public:
 
 	    /**
 	     * Default constructor creates an empty chain
 	     */
 	    extension_chain_t() { }
 	    /**
 	     * Create extension chain with a single extension in it
 	     */
 	    extension_chain_t(extension_t *e) { push_back(e); }
 
-	    virtual void checkid_hook(params_t& p,const string& identity);
-	    virtual void id_res_hook(const params_t& p,const params_t& sp,const string& identity);
-	    virtual void checkid_hook(const params_t& pin,params_t& pout);
+	    virtual void checkid_hook(basic_openid_message& om);
+	    virtual void id_res_hook(const basic_openid_message& om,const basic_openid_message& sp);
+	    virtual void checkid_hook(const basic_openid_message& inm,basic_openid_message& oum);
     };
 
 }
 
 #endif /* __OPKELE_EXTENSION_CHAIN_H */
diff --git a/include/opkele/prequeue_rp.h b/include/opkele/prequeue_rp.h
new file mode 100644
index 0000000..b98dd5a
--- a/dev/null
+++ b/include/opkele/prequeue_rp.h
@@ -0,0 +1,81 @@
+#ifndef __OPKELE_RP_H
+#define __OPKELE_RP_H
+
+#include <string>
+#include <set>
+#include <iterator>
+#include <opkele/basic_rp.h>
+
+namespace opkele {
+    using std::string;
+    using std::set;
+    using std::iterator;
+    using std::output_iterator_tag;
+
+    class prequeue_RP : public basic_RP {
+	public:
+	    /**
+	     * @name Session persistent store API
+	     * @{
+	     */
+	    /**
+	     * Called before queueing discovered endpoints. Typically happens
+	     * while initiating authentication session.
+	     * @see queue_endpoint()
+	     * @see end_queueing()
+	     */
+	    virtual void begin_queueing() { }
+	    /**
+	     * Used to queue discovered endpoint. It is implementors
+	     * responsibility to store the endpoint wherever he choses to store
+	     * it.
+	     * @param oep the endpoint to queue
+	     * @see begin_queueing()
+	     * @see end_queueing()
+	     */
+	    virtual void queue_endpoint(const openid_endpoint_t& oep) = 0;
+	    /**
+	     * Called after all discovered endpoints were queued. Implementor
+	     * may chose to use this virtual to commit endpoints queue to
+	     * persistent store.
+	     * @see begin_queueing()
+	     * @see queue_endpoint()
+	     */
+	    virtual void end_queueing() { }
+
+	    /**
+	     * Used to store normalized id when initiating request.
+	     * The default implementation does nothing, because implementor
+	     * doesn't have to care.
+	     * @param nid normalized id
+	     * @see get_normalzied_id()
+	     */
+	    virtual void set_normalized_id(const string& nid);
+	    /**
+	     * Return the normalized id previously set by set_normalized_id().
+	     * Provided for the sake of completeness because default
+	     * implementation doesn't use it.
+	     * @return the normalized identity
+	     */
+	    virtual const string get_normalized_id() const;
+	    /**
+	     * @}
+	     */
+
+	    /**
+	     * @name Actions
+	     * @{
+	     */
+	    void initiate(const string& usi);
+
+	    /**
+	     * @}
+	     */
+
+	    void verify_OP(const string& OP,
+		    const string& claimed_id,const string& identity) const;
+    };
+
+}
+
+#endif /* __OPKELE_RP_H */
diff --git a/include/opkele/sreg.h b/include/opkele/sreg.h
index df37a86..24cb315 100644
--- a/include/opkele/sreg.h
+++ b/include/opkele/sreg.h
@@ -129,33 +129,33 @@ namespace opkele {
 	     * @see fields_required
 	     * @param fo optional fields
 	     * @see fields_optional
 	     * @param pu policy url
 	     * @see policy_url
 	     */
 	    sreg_t(long fr=fields_NONE,long fo=fields_NONE,const string& pu="")
 		: fields_required(fr), fields_optional(fo), policy_url(pu), has_fields(0) { }
 
 	    /**
 	     * Implementation of consumer's checkid hook
 	     */
-	    virtual void checkid_hook(params_t& p,const string& identity);
+	    virtual void checkid_hook(basic_openid_message& om);
 	    /**
 	     * Implementation of consumer's id_res hook
 	     */
-	    virtual void id_res_hook(const params_t& p,const params_t& sp,const string& identity);
+	    virtual void id_res_hook(const basic_openid_message& om,const basic_openid_message& sp);
 	    /**
 	     * Implementation of server's checkid_hook
 	     */
-	    virtual void checkid_hook(const params_t& pin,params_t& pout);
+	    virtual void checkid_hook(const basic_openid_message& inm,basic_openid_message& oum);
 
 	    /**
 	     * Check and see if we have value for some particular field.
 	     * @param fb field in question
 	     * @see fieldbit_t
 	     * @return true if the value is available
 	     */
 	    bool has_field(fieldbit_t fb) const { return has_fields&fb; }
 
 	    /**
 	     * Retrieve the value for a field.
 	     * @param fb field in question
@@ -186,18 +186,18 @@ namespace opkele {
 	    void clear();
 
 	    /**
 	     * Function called after parsing sreg request to set up response
 	     * fields. The default implementation tries to send as much fields
 	     * as we have. The function is supposed to set the data and
 	     * fields_response.
 	     * @see fields_response
 	     * @param pin input request parameters with "openid." prefix
 	     * @param pout output request parameters without "openid." prefix.
 	     * @see checkid_hook(const params_t&,params_t&)
 	     */
-	    virtual void setup_response(const params_t& pin,params_t& pout);
+	    virtual void setup_response(const basic_openid_message& inm,basic_openid_message& oum);
 
     };
 }
 
 #endif /* __OPKELE_SREG_H */
diff --git a/include/opkele/types.h b/include/opkele/types.h
index de44a5c..d5ad258 100644
--- a/include/opkele/types.h
+++ b/include/opkele/types.h
@@ -2,33 +2,38 @@
 #define __OPKELE_TYPES_H
 
 /**
  * @file
  * @brief various types declarations
  */
 
 #include <ostream>
 #include <vector>
 #include <string>
 #include <map>
 #include <set>
+#include <list>
+#include <opkele/iterator.h>
 #include <opkele/tr1-mem.h>
 
 namespace opkele {
     using std::vector;
     using std::string;
     using std::map;
     using std::ostream;
     using std::multimap;
     using std::set;
+    using std::list;
+    using std::iterator;
+    using std::forward_iterator_tag;
 
     /**
      * the OpenID operation mode
      */
     typedef enum _mode_t {
 	mode_associate,
 	mode_checkid_immediate,
 	mode_checkid_setup,
 	mode_check_association
     } mode_t;
 
     /**
@@ -102,145 +107,101 @@ namespace opkele {
 	    /**
 	     * check whether the association is expired.
 	     * @return true if expired
 	     */
 	    virtual bool is_expired() const = 0;
     };
 
     /**
      * the shared_ptr<> for association_t object type
      */
     typedef tr1mem::shared_ptr<association_t> assoc_t;
 
+    class basic_openid_message {
+	public:
+	    typedef list<string> fields_t;
+	    typedef util::forward_iterator_proxy<
+		string,const string&,const string*
+		> fields_iterator;
+
+	    basic_openid_message() { }
+	    basic_openid_message(const basic_openid_message& x);
+	    void copy_to(basic_openid_message& x) const;
+
+	    virtual bool has_field(const string& n) const = 0;
+	    virtual const string& get_field(const string& n) const = 0;
+
+	    virtual bool has_ns(const string& uri) const;
+	    virtual string get_ns(const string& uri) const;
+
+	    virtual fields_iterator fields_begin() const = 0;
+	    virtual fields_iterator fields_end() const = 0;
+
+	    virtual string append_query(const string& url) const;
+	    virtual string query_string() const;
+
+
+	    virtual void reset_fields();
+	    virtual void set_field(const string& n,const string& v);
+	    virtual void reset_field(const string& n);
+
+	    virtual void from_keyvalues(const string& kv);
+
+	    void add_to_signed(const string& fields);
+	    string find_ns(const string& uri,const char *pfx) const;
+	    string allocate_ns(const string& uri,const char *pfx);
+    };
+
+    class openid_message_t : public basic_openid_message, public map<string,string> {
+	public:
+	    openid_message_t() { }
+	    openid_message_t(const basic_openid_message& x)
+		: basic_openid_message(x) { }
+
+	    void copy_to(basic_openid_message& x) const;
+
+	    bool has_field(const string& n) const;
+	    const string& get_field(const string& n) const;
+	    virtual fields_iterator fields_begin() const;
+	    virtual fields_iterator fields_end() const;
+
+	    void reset_fields();
+	    void set_field(const string& n,const string& v);
+	    void reset_field(const string& n);
+    };
+
     /**
      * request/response parameters map
      */
-    class params_t : public map<string,string> {
+    class params_t : public openid_message_t {
 	public:
 
 	    /**
 	     * check whether the parameter is present.
 	     * @param n the parameter name
 	     * @return true if yes
 	     */
-	    bool has_param(const string& n) const;
+	    bool has_param(const string& n) const {
+		return has_field(n); }
 	    /**
 	     * retrieve the parameter (const version)
 	     * @param n the parameter name
 	     * @return the parameter value
 	     * @throw failed_lookup if there is no such parameter
 	     */
-	    const string& get_param(const string& n) const;
-	    /**
-	     * retrieve the parameter.
-	     * @param n the parameter name
-	     * @return the parameter value
-	     * @throw failed_lookup if there is no such parameter
-	     */
-	    string& get_param(const string& n);
+	    const string& get_param(const string& n) const {
+		return get_field(n); }
 
 	    /**
 	     * parse the OpenID key/value data.
 	     * @param kv the OpenID key/value data
 	     */
-	    void parse_keyvalues(const string& kv);
-	    /**
-	     * sign the fields.
-	     * @param secret the secret used for signing
-	     * @param sig reference to the string, containing base64-encoded
-	     * result
-	     * @param slist the comma-separated list of fields to sign
-	     * @param prefix the string to prepend to parameter names
-	     */
-	    void sign(secret_t secret,string& sig,const string& slist,const char *prefix=0) const;
+	    void parse_keyvalues(const string& kv) {
+		from_keyvalues(kv); }
 
-	    /**
-	     * append parameters to the URL as a GET-request parameters.
-	     * @param url the base URL
-	     * @param prefix the string to prepend to parameter names
-	     * @return the ready-to-use location
-	     */
 	    string append_query(const string& url,const char *prefix = "openid.") const;
 
-	    /**
-	     * make up a query string suitable for use in GET and POST
-	     * requests.
-	     * @param prefix string to prened to parameter names
-	     * @return query string
-	     */
-	    string query_string(const char *prefix = "openid.") const;
-    };
-
-    /**
-     * dump the key/value pairs for the parameters to the stream.
-     * @param o output stream
-     * @param p the parameters
-     */
-    ostream& operator << (ostream& o,const params_t& p);
-
-    namespace xrd {
-
-	struct priority_compare {
-	    inline bool operator()(long a,long b) const {
-		return (a<0) ? false : (b<0) ? true : (a<b);
-	    }
-	};
-
-	template <typename _DT>
-	    class priority_map : public multimap<long,_DT,priority_compare> {
-		typedef multimap<long,_DT,priority_compare> map_type;
-		public:
-
-		    inline _DT& add(long priority,const _DT& d) {
-			return insert(typename map_type::value_type(priority,d))->second;
-		    }
 	    };
 
-	typedef priority_map<string> canonical_ids_t;
-	typedef priority_map<string> local_ids_t;
-	typedef set<string> types_t;
-	typedef priority_map<string> uris_t;
-
-	class service_t {
-	    public:
-		types_t types;
-		uris_t uris;
-		local_ids_t local_ids;
-		string provider_id;
-
-		void clear() {
-		    types.clear();
-		    uris.clear(); local_ids.clear();
-		    provider_id.clear();
-		}
-	};
-	typedef priority_map<service_t> services_t;
-
-	class XRD_t {
-	    public:
-		time_t expires;
-
-		canonical_ids_t canonical_ids;
-		local_ids_t local_ids;
-		services_t services;
-		string provider_id;
-
-		void clear() {
-		    expires = 0;
-		    canonical_ids.clear(); local_ids.clear();
-		    services.clear();
-		    provider_id.clear();
-		}
-		bool empty() const {
-		    return
-			canonical_ids.empty()
-			&& local_ids.empty()
-			&& services.empty();
-		}
-
-	};
-
-    }
-
 }
 
 #endif /* __OPKELE_TYPES_H */
diff --git a/include/opkele/util.h b/include/opkele/util.h
index 085c9e6..e9176b0 100644
--- a/include/opkele/util.h
+++ b/include/opkele/util.h
@@ -1,20 +1,21 @@
 #ifndef __OPKELE_UTIL_H
 #define __OPKELE_UTIL_H
 
 #include <time.h>
 #include <string>
 #include <vector>
 #include <openssl/bn.h>
 #include <openssl/dh.h>
+#include <opkele/types.h>
 
 namespace opkele {
     using std::string;
     using std::vector;
 
     /**
      * @brief opkele utils namespace
      */
     namespace util {
 
 	/**
 	 * Convenience class encapsulating SSL BIGNUM object for the purpose of
@@ -127,17 +128,24 @@ namespace opkele {
 	 */
 	void decode_base64(const string& data,vector<unsigned char>& rv);
 
 	/**
 	 * Normalize http(s) URI according to RFC3986, section 6. URI is
 	 * expected to have scheme: in front of it.
 	 * @param uri URI
 	 * @return normalized URI
 	 * @throw not_implemented in case of non-httpi(s) URI
 	 * @throw bad_input in case of malformed URI
 	 */
 	string rfc_3986_normalize_uri(const string& uri);
+
+	string& strip_uri_fragment_part(string& uri);
+
+	string abi_demangle(const char* mn);
+
+	string base64_signature(const assoc_t& assoc,const basic_openid_message& om);
+
     }
 
 }
 
 #endif /* __OPKELE_UTIL_H */
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
@@ -145,25 +145,25 @@ namespace opkele {
 	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())
@@ -213,25 +213,25 @@ namespace opkele {
 	    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);
 	    }
 	}
diff --git a/lib/discovery.cc b/lib/discovery.cc
index d868308..93409f4 100644
--- a/lib/discovery.cc
+++ b/lib/discovery.cc
@@ -9,28 +9,45 @@
 #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;
     }
 
@@ -39,25 +56,25 @@ namespace opkele {
 	    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;
@@ -75,93 +92,132 @@ namespace opkele {
 		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)
@@ -190,35 +246,39 @@ namespace opkele {
 
 	    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;
@@ -301,25 +361,26 @@ namespace opkele {
 			    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")) {
@@ -427,20 +488,50 @@ namespace opkele {
 			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
@@ -100,25 +100,25 @@ namespace opkele {
 	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");
 	}
diff --git a/lib/sreg.cc b/lib/sreg.cc
index 03edf57..7e2d588 100644
--- a/lib/sreg.cc
+++ b/lib/sreg.cc
@@ -19,49 +19,60 @@ namespace opkele {
 	{ "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;
@@ -85,42 +96,45 @@ namespace opkele {
 	    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
@@ -1,25 +1,31 @@
 #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());
@@ -196,26 +202,25 @@ namespace opkele {
 		     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;
@@ -302,15 +307,77 @@ namespace opkele {
 		     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);
+	}
+
     }
 
 }