Diffie Hellman PKCS #3 parameters now contain the recommended private key size.

By using the recommended key size the calculations for the server side are
reduced, giving a 50% increase in DH calculations.

5 files changed, 14 insertions, 13 deletions

diff --git a/lib/auth/anon.c b/lib/auth/anon.c
index 926bab650a..49efb497c6 100644
--- a/lib/auth/anon.c
+++ b/lib/auth/anon.c
@@ -99,7 +99,7 @@ gen_anon_server_kx (gnutls_session_t session, gnutls_buffer_st* data)
 
   _gnutls_dh_set_group (session, g, p);
 
-  ret = _gnutls_dh_common_print_server_kx (session, g, p, data);
+  ret = _gnutls_dh_common_print_server_kx (session, g, p, dh_params->q_bits, data);
   if (ret < 0)
     {
       gnutls_assert ();
diff --git a/lib/auth/dh_common.c b/lib/auth/dh_common.c
index 484fe4fceb..7a93d83789 100644
--- a/lib/auth/dh_common.c
+++ b/lib/auth/dh_common.c
@@ -129,7 +129,7 @@ _gnutls_gen_dh_common_client_kx_int (gnutls_session_t session, gnutls_buffer_st*
   int ret;
 
   X = gnutls_calc_dh_secret (&x, session->key->client_g,
-                             session->key->client_p);
+                             session->key->client_p, 0);
   if (X == NULL || x == NULL)
     {
       gnutls_assert ();
@@ -283,17 +283,17 @@ _gnutls_proc_dh_common_server_kx (gnutls_session_t session,
   return ret;
 }
 
-/* If the psk flag is set, then an empty psk_identity_hint will
- * be inserted */
 int
 _gnutls_dh_common_print_server_kx (gnutls_session_t session,
-                                   bigint_t g, bigint_t p, gnutls_buffer_st* data)
+                                   bigint_t g, bigint_t p, unsigned int q_bits,
+                                   gnutls_buffer_st* data)
 {
-  bigint_t x, X;
+  bigint_t x, Y;
   int ret;
 
-  X = gnutls_calc_dh_secret (&x, g, p);
-  if (X == NULL || x == NULL)
+  /* Y=g^x mod p */
+  Y = gnutls_calc_dh_secret (&x, g, p, q_bits);
+  if (Y == NULL || x == NULL)
     {
       gnutls_assert ();
       return GNUTLS_E_MEMORY_ERROR;
@@ -316,7 +316,7 @@ _gnutls_dh_common_print_server_kx (gnutls_session_t session,
       goto cleanup;
     }
 
-  ret = _gnutls_buffer_append_mpi(data, 16, X, 0);
+  ret = _gnutls_buffer_append_mpi(data, 16, Y, 0);
   if (ret < 0)
     {
       ret = gnutls_assert_val(ret);
@@ -324,7 +324,7 @@ _gnutls_dh_common_print_server_kx (gnutls_session_t session,
     }
 
 cleanup:
-  _gnutls_mpi_release (&X);
+  _gnutls_mpi_release (&Y);
 
   return data->length;
 }
diff --git a/lib/auth/dh_common.h b/lib/auth/dh_common.h
index 20fc6983db..2ff976a9a4 100644
--- a/lib/auth/dh_common.h
+++ b/lib/auth/dh_common.h
@@ -42,7 +42,8 @@ int _gnutls_proc_dh_common_client_kx (gnutls_session_t session,
                                       bigint_t p, bigint_t g,
                                       gnutls_datum_t* psk_key);
 int _gnutls_dh_common_print_server_kx (gnutls_session_t, bigint_t g,
-                                       bigint_t p, gnutls_buffer_st* data);
+                                       bigint_t p, unsigned int q_bits, 
+                                       gnutls_buffer_st* data);
 int _gnutls_proc_dh_common_server_kx (gnutls_session_t session, opaque * data,
                                       size_t _data_size);
 
diff --git a/lib/auth/dhe.c b/lib/auth/dhe.c
index 5e9d5e0a17..87496af17d 100644
--- a/lib/auth/dhe.c
+++ b/lib/auth/dhe.c
@@ -168,7 +168,7 @@ gen_dhe_server_kx (gnutls_session_t session, gnutls_buffer_st* data)
 
       _gnutls_dh_set_group (session, g, p);
 
-      ret = _gnutls_dh_common_print_server_kx (session, g, p, data);
+      ret = _gnutls_dh_common_print_server_kx (session, g, p, dh_params->q_bits, data);
     }
   else
     {
diff --git a/lib/auth/dhe_psk.c b/lib/auth/dhe_psk.c
index d1417e34de..7170c0b11c 100644
--- a/lib/auth/dhe_psk.c
+++ b/lib/auth/dhe_psk.c
@@ -177,7 +177,7 @@ gen_psk_server_kx (gnutls_session_t session, gnutls_buffer_st* data)
   if (ret < 0)
     return gnutls_assert_val(ret);
 
-  ret = _gnutls_dh_common_print_server_kx (session, g, p, data);
+  ret = _gnutls_dh_common_print_server_kx (session, g, p, dh_params->q_bits, data);
   if (ret < 0)
     gnutls_assert ();