1 files changed, 27 insertions, 1 deletions

diff --git a/src/lib/libcrypto/ec/ec_cvt.c b/src/lib/libcrypto/ec/ec_cvt.c
index d45640bab9..bfcbab35fe 100644
--- a/src/lib/libcrypto/ec/ec_cvt.c
+++ b/src/lib/libcrypto/ec/ec_cvt.c
@@ -78,7 +78,32 @@ EC_GROUP *EC_GROUP_new_curve_GFp(const BIGNUM *p, const BIGNUM *a, const BIGNUM
         const EC_METHOD *meth;
         EC_GROUP *ret;
 
+#if defined(OPENSSL_BN_ASM_MONT)
+        /*
+         * This might appear controversial, but the fact is that generic
+         * prime method was observed to deliver better performance even
+         * for NIST primes on a range of platforms, e.g.: 60%-15%
+         * improvement on IA-64, ~25% on ARM, 30%-90% on P4, 20%-25%
+         * in 32-bit build and 35%--12% in 64-bit build on Core2...
+         * Coefficients are relative to optimized bn_nist.c for most
+         * intensive ECDSA verify and ECDH operations for 192- and 521-
+         * bit keys respectively. Choice of these boundary values is
+         * arguable, because the dependency of improvement coefficient
+         * from key length is not a "monotone" curve. For example while
+         * 571-bit result is 23% on ARM, 384-bit one is -1%. But it's
+         * generally faster, sometimes "respectfully" faster, sometimes
+         * "tolerably" slower... What effectively happens is that loop
+         * with bn_mul_add_words is put against bn_mul_mont, and the
+         * latter "wins" on short vectors. Correct solution should be
+         * implementing dedicated NxN multiplication subroutines for
+         * small N. But till it materializes, let's stick to generic
+         * prime method...
+         *                                              <appro>
+         */
+        meth = EC_GFp_mont_method();
+#else
         meth = EC_GFp_nist_method();
+#endif
         
         ret = EC_GROUP_new(meth);
         if (ret == NULL)
@@ -122,7 +147,7 @@ EC_GROUP *EC_GROUP_new_curve_GFp(const BIGNUM *p, const BIGNUM *a, const BIGNUM
         return ret;
         }
 
-
+#ifndef OPENSSL_NO_EC2M
 EC_GROUP *EC_GROUP_new_curve_GF2m(const BIGNUM *p, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
         {
         const EC_METHOD *meth;
@@ -142,3 +167,4 @@ EC_GROUP *EC_GROUP_new_curve_GF2m(const BIGNUM *p, const BIGNUM *a, const BIGNUM
 
         return ret;
         }
+#endif