Moved rsa blinding code to a separate file.

1 files changed, 3 insertions, 40 deletions

diff --git a/rsa-decrypt-tr.c b/rsa-decrypt-tr.c
index d130a069..1e21e985 100644
--- a/rsa-decrypt-tr.c
+++ b/rsa-decrypt-tr.c
@@ -33,47 +33,10 @@
 #include "bignum.h"
 #include "pkcs1.h"
 
-/* Blinds the c, by computing c *= r^e (mod n), for a random r. Also
-   returns the inverse (ri), for use by rsa_unblind. */
-static void
-rsa_blind (const struct rsa_public_key *pub,
-	   void *random_ctx, nettle_random_func random,
-	   mpz_t c, mpz_t ri)
-{
-  mpz_t r;
-
-  mpz_init(r);
-
-  /* c = c*(r^e)
-   * ri = r^(-1)
-   */
-  do 
-    {
-      nettle_mpz_random(r, random_ctx, random, pub->n);
-      /* invert r */
-    }
-  while (!mpz_invert (ri, r, pub->n));
-
-  /* c = c*(r^e) mod n */
-  mpz_powm(r, r, pub->e, pub->n);
-  mpz_mul(c, c, r);
-  mpz_fdiv_r(c, c, pub->n);
-
-  mpz_clear(r);
-}
-
-/* c *= ri mod n */
-static void
-rsa_unblind (const struct rsa_public_key *pub, mpz_t c, const mpz_t ri)
-{
-  mpz_mul(c, c, ri);
-  mpz_fdiv_r(c, c, pub->n);
-}
-
 int
 rsa_decrypt_tr(const struct rsa_public_key *pub,
 	       const struct rsa_private_key *key,
-	       void *random_ctx, nettle_random_func random,	       
+	       void *random_ctx, nettle_random_func random,
 	       unsigned *length, uint8_t *message,
 	       const mpz_t gibberish)
 {
@@ -83,9 +46,9 @@ rsa_decrypt_tr(const struct rsa_public_key *pub,
   mpz_init_set(m, gibberish);
   mpz_init (ri);
 
-  rsa_blind (pub, random_ctx, random, m, ri);
+  _rsa_blind (pub, random_ctx, random, m, ri);
   rsa_compute_root(key, m, m);
-  rsa_unblind (pub, m, ri);
+  _rsa_unblind (pub, m, ri);
   mpz_clear (ri);
 
   res = pkcs1_decrypt (key->size, m, length, message);