9 files changed, 127 insertions, 28 deletions

diff --git a/include/Makefile.am b/include/Makefile.am
index b014752..72931eb 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -1,11 +1,12 @@
 nobase_include_HEADERS = \
         opkele/acconfig.h \
         opkele/opkele-config.h \
         opkele/types.h \
         opkele/association.h \
         opkele/exception.h \
         opkele/server.h \
-        opkele/consumer.h
+        opkele/consumer.h \
+        opkele/extension.h
 EXTRA_DIST = \
         opkele/data.h \
         opkele/util.h
diff --git a/include/opkele/consumer.h b/include/opkele/consumer.h
index 9932315..f9939cf 100644
--- a/include/opkele/consumer.h
+++ b/include/opkele/consumer.h
@@ -1,16 +1,17 @@
 #ifndef __OPKELE_CONSUMER_H
 #define __OPKELE_CONSUMER_H
 
 #include <opkele/types.h>
+#include <opkele/extension.h>
 
 /**
  * @file
  * @brief OpenID consumer-side functionality
  */
 
 /**
  * @brief the main opkele namespace
  */
 namespace opkele {
 
     /**
@@ -73,63 +74,65 @@ namespace opkele {
              * @param server the OpenID server
              * @return the auto_ptr<> for the newly allocated association_t
              * object, representing established association
              * @throw exception in case of error
              */
             assoc_t associate(const string& server);
             /**
              * prepare the parameters for the checkid_immediate
              * request.
              * @param identity the identity to verify
              * @param return_to the return_to url to pass with the request
              * @param trust_root the trust root to advertise with the request
+             * @param ext pointer to an extension(s) hooks object
              * @return the location string
              * @throw exception in case of error
              */
-            string checkid_immediate(const string& identity,const string& return_to,const string& trust_root="");
+            string checkid_immediate(const string& identity,const string& return_to,const string& trust_root="",extension_t *ext=0);
             /**
              * prepare the parameters for the checkid_setup
              * request.
              * @param identity the identity to verify
              * @param return_to the return_to url to pass with the request
              * @param trust_root the trust root to advertise with the request
+             * @param ext pointer to an extension(s) hooks object
              * @return the location string
              * @throw exception in case of error
              */
-            string checkid_setup(const string& identity,const string& return_to,const string& trust_root="");
+            string checkid_setup(const string& identity,const string& return_to,const string& trust_root="",extension_t *ext=0);
             /**
              * the actual implementation behind checkid_immediate() and
              * checkid_setup() functions.
              * @param mode checkid_* mode - either mode_checkid_immediate or mode_checkid_setup
              * @param identity the identity to verify
              * @param return_to the return_to url to pass with the request
              * @param trust_root the trust root to advertise with the request
+             * @param ext pointer to an extension(s) hooks object
              * @return the location string
              * @throw exception in case of error
              */
-            string checkid_(mode_t mode,const string& identity,const string& return_to,const string& trust_root="");
+            string checkid_(mode_t mode,const string& identity,const string& return_to,const string& trust_root="",extension_t *ext=0);
             /**
              * verify the id_res response
              * @param pin the response parameters
-             * @param identity the identity being checked (if not specified, extracted
-             * from the openid.identity parameter
-             * @throw id_res_mismatch in case of signature
-             * mismatch
-             * @throw id_res_setup in case of
-             * openid.user_setup_url failure (supposedly
-             * checkid_immediate only)
+             * @param identity the identity being checked (if not specified,
+             * @param ext pointer to an extension(s) hooks object
+             * extracted from the openid.identity parameter
+             * @throw id_res_mismatch in case of signature mismatch
+             * @throw id_res_setup in case of openid.user_setup_url failure
+             * (supposedly checkid_immediate only)
              * @throw id_res_failed in case of failure
              * @throw exception in case of other failures
              */
-            void id_res(const params_t& pin,const string& identity="");
+            void id_res(const params_t& pin,const string& identity="",extension_t *ext=0);
             /**
              * perform a check_authentication request.
              * @param server the OpenID server
              * @param p request parameters
              */
             void check_authentication(const string& server,const params_t& p);
 
             /**
              * make URL canonical, by adding http:// and trailing slash, if needed.
              * @param url
              * @return canonicalized url
              */
diff --git a/include/opkele/exception.h b/include/opkele/exception.h
index c5f5811..9fc9bd3 100644
--- a/include/opkele/exception.h
+++ b/include/opkele/exception.h
@@ -196,15 +196,25 @@ namespace opkele {
      * network operation related error occured, specifically, related to
      * libcurl
      */
     class exception_curl : public exception_network {
         public:
             CURLcode _error;
             string _curl_string;
             exception_curl(OPKELE_E_PARS);
             exception_curl(OPKELE_E_PARS,CURLcode e);
             ~exception_curl() throw() { }
     };
 
+    /**
+     * not implemented (think pure virtual) member function executed, signfies
+     * programmer error
+     */
+    class not_implemented : public exception {
+        public:
+            not_implemented(OPKELE_E_PARS)
+                : exception(OPKELE_E_CONS) { }
+    };
+
 }
 
 #endif /* __OPKELE_EXCEPTION_H */
diff --git a/include/opkele/extension.h b/include/opkele/extension.h
new file mode 100644
index 0000000..3fb5f6e
--- a/dev/null
+++ b/include/opkele/extension.h
@@ -0,0 +1,59 @@
+#ifndef __OPKELE_EXTENSIONS_H
+#define __OPKELE_EXTENSIONS_H
+
+/**
+ * @file
+ * @brief extensions framework basics
+ */
+
+#include <opkele/types.h>
+
+/**
+ * @brief the main opkele namespace
+ */
+namespace opkele {
+
+    /**
+     * OpenID consumer extension hooks base class
+     */
+    class extension_t {
+        public:
+            /**
+             * 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
+             */
+            virtual void checkid_hook(params_t& p,const string& identity);
+            /**
+             * 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
+             */
+            virtual void id_res_hook(const params_t& p,const params_t& sp,const string& identity);
+
+            /**
+             * 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
+             * @param put response parameters list
+             */
+            virtual void checkid_hook(const params_t& pin,params_t& pout);
+
+            /**
+             * Casts the object to pointer to itself. For convenient passing
+             * of pointer.
+             */
+            operator extension_t*(void) { return this; }
+    };
+
+}
+
+#endif /* __OPKELE_EXTENSIONS_H */
diff --git a/include/opkele/server.h b/include/opkele/server.h
index fe07448..bf131d8 100644
--- a/include/opkele/server.h
+++ b/include/opkele/server.h
@@ -1,21 +1,22 @@
 #ifndef __OPKELE_SERVER_H
 #define __OPKELE_SERVER_H
 
 /**
  * @file
  * @brief OpenID server-side functionality
  */
 
 #include <opkele/types.h>
+#include <opkele/extension.h>
 
 /**
  * @brief the main opkele namespace
  */
 namespace opkele {
 
     /**
      * implementation of basic server functionality
      */
     class server_t {
         public:
 
@@ -51,45 +52,48 @@ namespace opkele {
 
             /**
              * process the associate request.
              * @param pin the incoming request parameters
              * @param pout the store for the response parameters
              */
             void associate(const params_t& pin,params_t& pout);
             /**
              * process the checkid_immediate request.
              * @param pin the incoming request parameters
              * @param return_to reference to the object to store return_to url to
              * @param pout the response parameters
+             * @param ext pointer to the extension hooks object
              * @throw exception in case of errors or negative reply
              */
-            void checkid_immediate(const params_t& pin,string& return_to,params_t& pout);
+            void checkid_immediate(const params_t& pin,string& return_to,params_t& pout,extension_t *ext=0);
             /**
              * process the checkid_setup request.
              * @param pin the incoming request parameters
              * @param return_to reference to the object to store return_to url to
              * @param pout the response parameters
+             * @param ext pointer to the extension hooks object
              * @throw exception in case of errors or negative reply
              */
-            void checkid_setup(const params_t& pin,string& return_to,params_t& pout);
+            void checkid_setup(const params_t& pin,string& return_to,params_t& pout,extension_t *ext=0);
             /**
              * the actual functionality behind checkid_immediate() and
              * checkid_setup()
              * @param mode the request being processed (either
              * mode_checkid_immediate or mode_checkid_setup)
              * @param pin the incoming request parameters
              * @param return_to reference to the object to store return_to url to
              * @param pout the response parameters
+             * @param ext pointer to the extension hooks object
              * @throw exception in case of errors or negative reply
              */
-            void checkid_(mode_t mode,const params_t& pin,string& return_to,params_t& pout);
+            void checkid_(mode_t mode,const params_t& pin,string& return_to,params_t& pout,extension_t *ext=0);
             /**
              * process the check_authentication request.
              * @param pin incoming request parameters
              * @param pout response parameters
              */
             void check_authentication(const params_t& pin,params_t& pout);
     };
 
 }
 
 #endif /* __OPKELE_SERVER_H */
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 6f3f9f3..69c749e 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -12,13 +12,14 @@ LDADD = \
         ${PCREPP_LIBS} \
         ${MIMETIC_LIBS} \
         ${OPENSSL_LIBS} \
         ${KONFORKA_LIBS}
 
 libopkele_la_SOURCES = \
                        params.cc \
                        util.cc \
                        server.cc \
                        secret.cc \
                        data.cc \
                        consumer.cc \
-                       exception.cc
+                       exception.cc \
+                       extension.cc
diff --git a/lib/consumer.cc b/lib/consumer.cc
index bb6358c..10c2fa0 100644
--- a/lib/consumer.cc
+++ b/lib/consumer.cc
@@ -114,81 +114,84 @@ namespace opkele {
             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) {
-        return checkid_(mode_checkid_immediate,identity,return_to,trust_root);
+    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) {
-        return checkid_(mode_checkid_setup,identity,return_to,trust_root);
+    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) {
+    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 {
             try {
                 string ah = find_assoc(server)->handle();
                 p["assoc_handle"] = ah;
             }catch(failed_lookup& fl) {
                 string ah = associate(server)->handle();
                 p["assoc_handle"] = ah;
             }
         }catch(exception& e) { }
+        if(ext) ext->checkid_hook(p,identity);
         return p.append_query(server);
     }
 
-    void consumer_t::id_res(const params_t& pin,const string& identity) {
+    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"));
             const string& sigenc = pin.get_param("openid.sig");
             mimetic::Base64::Decoder b;
             vector<unsigned char> sig;
             mimetic::decode(
                     sigenc.begin(),sigenc.end(), b,
                     back_insert_iterator<vector<unsigned char> >(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."))] = 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))
@@ -210,24 +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);
     }
 
     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/extension.cc b/lib/extension.cc
new file mode 100644
index 0000000..bd2195d
--- a/dev/null
+++ b/lib/extension.cc
@@ -0,0 +1,15 @@
+#include <opkele/exception.h>
+#include <opkele/extension.h>
+
+namespace opkele {
+
+    void extension_t::checkid_hook(params_t& p,const string& identity) {
+        throw not_implemented(OPKELE_CP_ "Consumer checkid_hook not implemented");
+    }
+    void id_res_hook(const params_t& p,const params_t& sp,const string& identity) {
+        throw not_implemented(OPKELE_CP_ "Consumer id_res_hook not implemented");
+    }
+    void checkid_hook(const params_t& pin,params_t& pout) {
+        throw not_implemented(OPKELE_CP_ "Server checkid_hook not implemented");
+    }
+}
diff --git a/lib/server.cc b/lib/server.cc
index 5eee1f3..8c29abb 100644
--- a/lib/server.cc
+++ b/lib/server.cc
@@ -58,33 +58,33 @@ namespace opkele {
         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) {
-        checkid_(mode_checkid_immediate,pin,return_to,pout);
+    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) {
-        checkid_(mode_checkid_setup,pin,return_to,pout);
+    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) {
+    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");
         }
@@ -97,25 +97,27 @@ namespace opkele {
         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.sign(assoc->secret(),pout["sig"],pout["signed"]="mode,identity,return_to");
+        pout["signed"]="mode,identity,return_to";
+        if(ext) ext->checkid_hook(pin,pout);
+        pout.sign(assoc->secret(),pout["sig"],pout["signed"]);
     }
 
     void server_t::check_authentication(const params_t& pin,params_t& pout) {
         vector<unsigned char>  sig;
         mimetic::Base64::Decoder b;
         const string& sigenc = pin.get_param("openid.sig");
         mimetic::decode(
                 sigenc.begin(),sigenc.end(), b,
                 back_insert_iterator<vector<unsigned char> >(sig));
         assoc_t assoc;
         try {
             assoc = retrieve_assoc(pin.get_param("openid.assoc_handle"));