basic_RP: add methods for accessing identity information passed from OP.

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

2 files changed, 63 insertions, 2 deletions

diff --git a/include/opkele/basic_rp.h b/include/opkele/basic_rp.h
index d5356aa..d096e0a 100644
--- a/include/opkele/basic_rp.h
+++ b/include/opkele/basic_rp.h
@@ -1,200 +1,236 @@
 #ifndef __OPKELE_BASIC_RP_H
 #define __OPKELE_BASIC_RP_H
 
 #include <string>
 #include <opkele/types.h>
 #include <opkele/extension.h>
 
 namespace opkele {
     using std::string;
 
     class basic_RP {
         public:
+            /**
+             * Claimed identifier from a parsed id_res message.
+             */
+            string claimed_id;
+            /**
+             * OP-Local identifier from a parsed id_res message.
+             */
+            string identity;
 
             virtual ~basic_RP() { }
 
+            void reset_vars();
+
+            /**
+             * @name Assertion information retrieval
+             * Retrieval of the information passed with openid message
+             * @{
+             */
+            /**
+             * Find out if the assertion is about identity
+             * @return true if so
+             */
+            bool has_identity() const;
+            /**
+             * Get claimed identifier supplied with the request
+             * @return claimed identifier
+             * @throw non_identity if request is not about identity
+             */
+            const string& get_claimed_id() const;
+            /**
+             * Get the identity (OP-Local identifier) confirmed
+             * @return identity
+             * @throw non_identity if request is not about identity
+             */
+            const string& get_identity() const;
+            /**
+             * @}
+             */
+
             /**
              * @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/lib/basic_rp.cc b/lib/basic_rp.cc
index e65d9fb..3357d0b 100644
--- a/lib/basic_rp.cc
+++ b/lib/basic_rp.cc
@@ -1,300 +1,325 @@
 #include <cassert>
 #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/util-internal.h>
 #include <opkele/curl.h>
+#include <opkele/debug.h>
 
 namespace opkele {
 
+    void basic_RP::reset_vars() {
+        claimed_id.clear(); identity.clear();
+    }
+
+    const string& basic_RP::get_claimed_id() const {
+        if(claimed_id.empty())
+            throw non_identity(OPKELE_CP_ "attempting to retreive claimed_id of non-identity assertion");
+        assert(!identity.empty());
+        return claimed_id;
+    }
+
+    const string& basic_RP::get_identity() const {
+        if(identity.empty())
+            throw non_identity(OPKELE_CP_ "attempting to retrieve identity of non-identity related assertion");
+        assert(!claimed_id.empty());
+        return identity;
+    }
+
     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*),
             size_t exp_s_len) 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; }
         assert(d_len<=SHA256_DIGEST_LENGTH);
         unsigned char key_digest[SHA256_DIGEST_LENGTH];
         secret.enxor_from_base64((*d_fun)(ckptr,cklen,key_digest),om.get_field("enc_mac_key"));
         if(secret.size()!=exp_s_len)
             throw bad_input(OPKELE_CP_ "Secret length isn't consistent with association type");
     }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, SHA256_DIGEST_LENGTH );
             expires_in = util::string_to_long(res.get_field("expires_in"));
         }catch(exception&) {
             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, SHA_DIGEST_LENGTH );
                 expires_in = util::string_to_long(res.get_field("expires_in"));
             }catch(bad_input&) {
                 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->rp_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) {
+        reset_vars();
         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(size_t 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")) {
+                claimed_id = om.get_field("claimed_id");
+                identity = om.get_field("identity");
                 verify_OP(
                         om.get_field("op_endpoint"),
-                        om.get_field("claimed_id"),
-                        om.get_field("identity") );
+                        claimed_id, identity );
             }
 
+        }else{
+            claimed_id = get_endpoint().claimed_id;
+            /* TODO: check if this is the identity we asked for */
+            identity = om.get_field("identity");
         }
         if(ext) ext->rp_id_res_hook(om,signeds);
     }
 
     void basic_RP::check_authentication(const string& OP,
             const basic_openid_message& om){
         openid_message_t res;
         static const string checkauthmode = "check_authentication";
         direct_request(res,util::change_mode_message_proxy(om,checkauthmode),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");
     }
 
 }