fix EC_GROUP_copy for EC_GFp_nist_method()

Submitted by: Nils Larsch

crypto/ec/ec_lcl.h

@@ -322,6 +322,7 @@ int ec_GFp_recp_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a, BN_CTX *
 
 
 /* method functions in ecp_nist.c */
+int ec_GFp_nist_group_copy(EC_GROUP *dest, const EC_GROUP *src);
 int ec_GFp_nist_group_set_curve(EC_GROUP *, const BIGNUM *p, const BIGNUM *a, const BIGNUM *b, BN_CTX *);
 int ec_GFp_nist_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *);
 int ec_GFp_nist_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a, BN_CTX *);

crypto/ec/ecp_nist.c

@@ -72,7 +72,7 @@ const EC_METHOD *EC_GFp_nist_method(void)
 		ec_GFp_simple_group_init,
 		ec_GFp_simple_group_finish,
 		ec_GFp_simple_group_clear_finish,
-		ec_GFp_simple_group_copy,
+		ec_GFp_nist_group_copy,
 		ec_GFp_nist_group_set_curve,
 		ec_GFp_simple_group_get_curve,
 		ec_GFp_simple_group_get_degree,
@@ -114,6 +114,12 @@ const EC_METHOD *EC_GFp_nist_method(void)
 #define	NO_32_BIT_TYPE
 #endif
 
+int ec_GFp_nist_group_copy(EC_GROUP *dest, const EC_GROUP *src)
+	{
+	dest->field_mod_func = src->field_mod_func;
+
+	return ec_GFp_simple_group_copy(dest, src);
+	}
 
 int ec_GFp_nist_group_set_curve(EC_GROUP *group, const BIGNUM *p,
 	const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)