From: Dr. Stephen Henson <steve@openssl.org>
Date: Mon, 14 Feb 2011 16:44:29 +0000 (+0000)
Subject: New function BN_nist_mod_func which returns an appropriate function
X-Git-Tag: OpenSSL-fips-2_0-rc1~752
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=133291f8e73892dfd00923d278be74229ac07401;p=openssl

New function BN_nist_mod_func which returns an appropriate function
if the passed prime is a NIST prime.
---

diff --git a/crypto/bn/bn.h b/crypto/bn/bn.h
index 5897d2b314..0a66a2ea0c 100644
--- a/crypto/bn/bn.h
+++ b/crypto/bn/bn.h
@@ -674,6 +674,8 @@ const BIGNUM *BN_get0_nist_prime_256(void);
 const BIGNUM *BN_get0_nist_prime_384(void);
 const BIGNUM *BN_get0_nist_prime_521(void);
 
+int (*BN_nist_mod_func(const BIGNUM *p))(BIGNUM *r, const BIGNUM *a, const BIGNUM *field, BN_CTX *ctx);
+
 /* library internal functions */
 
 #define bn_expand(a,bits) ((((((bits+BN_BITS2-1))/BN_BITS2)) <= (a)->dmax)?\
diff --git a/crypto/bn/bn_nist.c b/crypto/bn/bn_nist.c
index 2ca5b01391..97f980a131 100644
--- a/crypto/bn/bn_nist.c
+++ b/crypto/bn/bn_nist.c
@@ -834,3 +834,18 @@ int BN_nist_mod_521(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 
 	return 1;
 	}
+
+int (*BN_nist_mod_func(const BIGNUM *p))(BIGNUM *r, const BIGNUM *a, const BIGNUM *field, BN_CTX *ctx)
+	{
+	if (BN_ucmp(&_bignum_nist_p_192, p) == 0)
+		return BN_nist_mod_192;
+	if (BN_ucmp(&_bignum_nist_p_224, p) == 0)
+		return BN_nist_mod_224;
+	if (BN_ucmp(&_bignum_nist_p_256, p) == 0)
+		return BN_nist_mod_256;
+	if (BN_ucmp(&_bignum_nist_p_384, p) == 0)
+		return BN_nist_mod_384;
+	if (BN_ucmp(&_bignum_nist_p_521, p) == 0)
+		return BN_nist_mod_521;
+	return 0;
+	}