1 files changed, 6 insertions, 5 deletions

diff --git a/lib/server.cc b/lib/server.cc
index e81d4b6..8db97be 100644
--- a/lib/server.cc
+++ b/lib/server.cc
@@ -1,169 +1,170 @@
 #include <vector>
 #include <openssl/sha.h>
 #include <openssl/hmac.h>
 #include <opkele/util.h>
 #include <opkele/exception.h>
 #include <opkele/server.h>
 #include <opkele/data.h>
 
 namespace opkele {
     using namespace std;
 
     void server_t::associate(const params_t& pin,params_t& pout) {
         util::dh_t dh;
         util::bignum_t c_pub;
         unsigned char key_sha1[SHA_DIGEST_LENGTH];
         enum {
             sess_cleartext,
             sess_dh_sha1
         } st = sess_cleartext;
         if(
                 pin.has_param("openid.session_type")
                 && pin.get_param("openid.session_type")=="DH-SHA1" ) {
             /* TODO: fallback to cleartext in case of exceptions here? */
             if(!(dh = DH_new()))
                 throw exception_openssl(OPKELE_CP_ "failed to DH_new()");
             c_pub = util::base64_to_bignum(pin.get_param("openid.dh_consumer_public"));
             if(pin.has_param("openid.dh_modulus"))
                 dh->p = util::base64_to_bignum(pin.get_param("openid.dh_modulus"));
             else
                 dh->p = util::dec_to_bignum(data::_default_p);
             if(pin.has_param("openid.dh_gen"))
                 dh->g = util::base64_to_bignum(pin.get_param("openid.dh_gen"));
             else
                 dh->g = util::dec_to_bignum(data::_default_g);
             if(!DH_generate_key(dh))
                 throw exception_openssl(OPKELE_CP_ "failed to DH_generate_key()");
-            vector<unsigned char> ck(DH_size(dh));
+            vector<unsigned char> ck(DH_size(dh)+1);
+            unsigned char *ckptr = &(ck.front())+1;
             int cklen = DH_compute_key(&(ck.front()),c_pub,dh);
             if(cklen<0)
                 throw exception_openssl(OPKELE_CP_ "failed to DH_compute_key()");
-            ck.resize(cklen);
-            // OpenID algorithm requires extra zero in case of set bit here
-            if(ck[0]&0x80) ck.insert(ck.begin(),1,0);
-            SHA1(&(ck.front()),ck.size(),key_sha1);
+            if(cklen && (*ckptr)&0x80) {
+                (*(--ckptr)) = 0; ++cklen;
+            }
+            SHA1(ckptr,cklen,key_sha1);
             st = sess_dh_sha1;
         }
         assoc_t assoc = alloc_assoc(mode_associate);
         time_t now = time(0);
         pout.clear();
         pout["assoc_type"] = assoc->assoc_type();
         pout["assoc_handle"] = assoc->handle();
         /* TODO: eventually remove deprecated stuff */
         pout["issued"] = util::time_to_w3c(now);
         pout["expiry"] = util::time_to_w3c(now+assoc->expires_in());
         pout["expires_in"] = util::long_to_string(assoc->expires_in());
         secret_t secret = assoc->secret();
         switch(st) {
             case sess_dh_sha1:
                 pout["session_type"] = "DH-SHA1";
                 pout["dh_server_public"] = util::bignum_to_base64(dh->pub_key);
                 secret.enxor_to_base64(key_sha1,pout["enc_mac_key"]);
                 break;
             default:
                 secret.to_base64(pout["mac_key"]);
                 break;
         }
     }
 
     void server_t::checkid_immediate(const params_t& pin,string& return_to,params_t& pout,extension_t *ext) {
         checkid_(mode_checkid_immediate,pin,return_to,pout,ext);
     }
 
     void server_t::checkid_setup(const params_t& pin,string& return_to,params_t& pout,extension_t *ext) {
         checkid_(mode_checkid_setup,pin,return_to,pout,ext);
     }
 
     void server_t::checkid_(mode_t mode,const params_t& pin,string& return_to,params_t& pout,extension_t *ext) {
         if(mode!=mode_checkid_immediate && mode!=mode_checkid_setup)
             throw bad_input(OPKELE_CP_ "invalid checkid_* mode");
         pout.clear();
         assoc_t assoc;
         try {
             assoc = retrieve_assoc(pin.get_param("openid.assoc_handle"));
         }catch(failed_lookup& fl) {
             // no handle specified or no valid handle found, going dumb
             assoc = alloc_assoc(mode_checkid_setup);
             if(pin.has_param("openid.assoc_handle"))
                 pout["invalidate_handle"]=pin.get_param("openid.assoc_handle");
         }
         string trust_root;
         try {
             trust_root = pin.get_param("openid.trust_root");
         }catch(failed_lookup& fl) { }
         string identity = pin.get_param("openid.identity");
         return_to = pin.get_param("openid.return_to");
         validate(*assoc,pin,identity,trust_root);
         pout["mode"] = "id_res";
         pout["assoc_handle"] = assoc->handle();
         if(pin.has_param("openid.assoc_handle") && assoc->stateless())
             pout["invalidate_handle"] = pin.get_param("openid.assoc_handle");
         pout["identity"] = identity;
         pout["return_to"] = return_to;
         /* TODO: eventually remove deprecated stuff */
         time_t now = time(0);
         pout["issued"] = util::time_to_w3c(now);
         pout["valid_to"] = util::time_to_w3c(now+120);
         pout["exipres_in"] = "120";
         pout["signed"]="mode,identity,return_to";
         if(ext) ext->checkid_hook(pin,pout);
         pout.sign(assoc->secret(),pout["sig"],pout["signed"]);
     }
 
     void server_t::check_authentication(const params_t& pin,params_t& pout) {
         vector<unsigned char>  sig;
         const string& sigenc = pin.get_param("openid.sig");
         util::decode_base64(sigenc,sig);
         assoc_t assoc;
         try {
             assoc = retrieve_assoc(pin.get_param("openid.assoc_handle"));
         }catch(failed_lookup& fl) {
             throw failed_assertion(OPKELE_CP_ "invalid handle or handle not specified");
         }
         if(!assoc->stateless())
             throw stateful_handle(OPKELE_CP_ "will not do check_authentication on a stateful handle");
         const string& slist = pin.get_param("openid.signed");
         string kv;
         string::size_type p =0;
         while(true) {
             string::size_type co = slist.find(',',p);
             string f = (co==string::npos)?slist.substr(p):slist.substr(p,co-p);
             kv += f;
             kv += ':';
             if(f=="mode")
                 kv += "id_res";
             else {
                 f.insert(0,"openid.");
                 kv += pin.get_param(f);
             }
             kv += '\n';
             if(co==string::npos)
                 break;
             p = co+1;
         }
         secret_t secret = assoc->secret();
         unsigned int md_len = 0;
         unsigned char *md = HMAC(
                 EVP_sha1(),
                 &(secret.front()),secret.size(),
                 (const unsigned char *)kv.data(),kv.length(),
                 0,&md_len);
         pout.clear();
         if(sig.size()==md_len && !memcmp(&(sig.front()),md,md_len)) {
             pout["is_valid"]="true";
             pout["lifetime"]="60"; /* TODO: eventually remove deprecated stuff */
         }else{
             pout["is_valid"]="false";
             pout["lifetime"]="0"; /* TODO: eventually remove deprecated stuff */
         }
         if(pin.has_param("openid.invalidate_handle")) {
             string h = pin.get_param("openid.invalidate_handle");
             try {
                 assoc_t assoc = retrieve_assoc(h);
             }catch(invalid_handle& ih) {
                 pout["invalidate_handle"] = h;
             }catch(failed_lookup& fl) { }
         }
     }
 
 }