1 files changed, 4 insertions, 44 deletions

diff --git a/rsa-pkcs1-sign-tr.c b/rsa-pkcs1-sign-tr.c
index f2b3e45d..00094b56 100644
--- a/rsa-pkcs1-sign-tr.c
+++ b/rsa-pkcs1-sign-tr.c
@@ -38,26 +38,6 @@
 
 #include "pkcs1.h"
 
-/* Checks for any errors done in the RSA computation. That avoids
- * attacks which rely on faults on hardware, or even software MPI
- * implementation. */
-static int
-rsa_verify_res(const struct rsa_public_key *pub,
-	       mpz_t s, mpz_t m)
-{
-  mpz_t t;
-  int res;
-
-  mpz_init(t);
-
-  mpz_powm(t, s, pub->e, pub->n);
-
-  res = !mpz_cmp(m, t);
-
-  mpz_clear(t);
-  return res;
-}
-
 /* Side-channel resistant version of rsa_pkcs1_sign() */
 int
 rsa_pkcs1_sign_tr(const struct rsa_public_key *pub,
@@ -66,34 +46,14 @@ rsa_pkcs1_sign_tr(const struct rsa_public_key *pub,
 	          size_t length, const uint8_t *digest_info,
    	          mpz_t s)
 {
-  mpz_t ri, m;
+  mpz_t m;
   int ret;
 
   mpz_init(m);
 
-  if (pkcs1_rsa_digest_encode (m, key->size, length, digest_info))
-    {
-      mpz_init (ri);
-
-      _rsa_blind (pub, random_ctx, random, m, ri);
-      rsa_compute_root(key, s, m);
-
-      if (rsa_verify_res(pub, s, m) == 0)
-        {
-          mpz_set_ui(s, 0);
-          ret = 0;
-        }
-      else
-        ret = 1;
-
-      _rsa_unblind (pub, s, ri);
-      mpz_clear (ri);
-    }
-  else
-    {
-      mpz_set_ui(s, 0);
-      ret = 0;
-    }    
+  ret = (pkcs1_rsa_digest_encode (m, key->size, length, digest_info)
+	 && rsa_compute_root_tr (pub, key, random_ctx, random,
+				 s, m));
   mpz_clear(m);
   return ret;
 }