From 28051fa99cd4163859429b852de69679e8d3c8c6 Mon Sep 17 00:00:00 2001
From: Jeffrey Altman <jaltman@secure-endpoints.com>
Date: Mon, 7 Oct 2013 15:13:18 -0500
Subject: [PATCH] Convert mp_find_prime to use mp_prime_is_prime

Modify the signature of mp_find_prime() to permit the number of
Miller-Rabin rounds to be specified.  In addition, valid responses
now include MP_NO, MP_YES, and MP_VAL which is returned when
mp_prime_is_prime() fails.

Change-Id: I0195129a4dd75875e6dddb6d49a5ceb30afb1a17
---
 lib/hcrypto/libtommath/bn_mp_find_prime.c | 15 ++++++++++++---
 lib/hcrypto/libtommath/tommath.h          |  2 +-
 lib/hcrypto/rsa-ltm.c                     |  4 ++--
 3 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/lib/hcrypto/libtommath/bn_mp_find_prime.c b/lib/hcrypto/libtommath/bn_mp_find_prime.c
index d007acbef..29ef8747d 100644
--- a/lib/hcrypto/libtommath/bn_mp_find_prime.c
+++ b/lib/hcrypto/libtommath/bn_mp_find_prime.c
@@ -6,16 +6,25 @@
  */
 #include <tommath.h>
 #ifdef BN_MP_FIND_PRIME_C
-int mp_find_prime(mp_int *a)
+int mp_find_prime(mp_int *a, int t)
 {
-  int res;
+  int res = MP_NO;
+
+  /* valid value of t? */
+  if (t <= 0 || t > PRIME_SIZE) {
+    return MP_VAL;
+  }
 
   if (mp_iseven(a))
     mp_add_d(a, 1, a);
 
   do {
+    if (mp_prime_is_prime(a, t, &res) != 0) {
+      res = MP_VAL;
+      break;
+    }
 
-    if ((res = mp_isprime(a)) == MP_NO) {
+    if (res == MP_NO) {
       mp_add_d(a, 2, a);
       continue;
     }
diff --git a/lib/hcrypto/libtommath/tommath.h b/lib/hcrypto/libtommath/tommath.h
index 67d3b06af..84d3f7a59 100644
--- a/lib/hcrypto/libtommath/tommath.h
+++ b/lib/hcrypto/libtommath/tommath.h
@@ -520,7 +520,7 @@ int mp_prime_next_prime(mp_int *a, int t, int bbs_style);
  */
 int mp_prime_random_ex(mp_int *a, int t, int size, int flags, ltm_prime_callback cb, void *dat);
 
-int mp_find_prime(mp_int *a);
+int mp_find_prime(mp_int *a, int t);
 
 int mp_isprime(mp_int *a);
 
diff --git a/lib/hcrypto/rsa-ltm.c b/lib/hcrypto/rsa-ltm.c
index 5cd3e9361..35d20b0a8 100644
--- a/lib/hcrypto/rsa-ltm.c
+++ b/lib/hcrypto/rsa-ltm.c
@@ -528,7 +528,7 @@ ltm_rsa_generate_key(RSA *rsa, int bits, BIGNUM *e, BN_GENCB *cb)
     do {
 	BN_GENCB_call(cb, 2, counter++);
 	CHECK(random_num(&p, bitsp), 0);
-	CHECK(mp_find_prime(&p), MP_YES);
+	CHECK(mp_find_prime(&p,128), MP_YES);
 
 	mp_sub_d(&p, 1, &t1);
 	mp_gcd(&t1, &el, &t2);
@@ -540,7 +540,7 @@ ltm_rsa_generate_key(RSA *rsa, int bits, BIGNUM *e, BN_GENCB *cb)
     do {
 	BN_GENCB_call(cb, 2, counter++);
 	CHECK(random_num(&q, bits - bitsp), 0);
-	CHECK(mp_find_prime(&q), MP_YES);
+	CHECK(mp_find_prime(&q,128), MP_YES);
 
 	if (mp_cmp(&p, &q) == 0) /* don't let p and q be the same */
 	    continue;