X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fbn%2Fbn_nist.c;h=bd04e7e29da55b253fd28f29d75c328c0fba22d4;hp=79f7c2ef2867ef12822894b275d27c53d3704008;hb=f8d6be3f8170c4aa3bea1618994f912629f3d0c3;hpb=078dd1a0f94394632614123af3155866749ff79c

diff --git a/crypto/bn/bn_nist.c b/crypto/bn/bn_nist.c
index 79f7c2ef28..bd04e7e29d 100644
--- a/crypto/bn/bn_nist.c
+++ b/crypto/bn/bn_nist.c
@@ -1,6 +1,9 @@
 /* crypto/bn/bn_nist.c */
+/*
+ * Written by Nils Larsch for the OpenSSL project
+ */
 /* ====================================================================
- * Copyright (c) 1998-2002 The OpenSSL Project.  All rights reserved.
+ * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -56,741 +59,651 @@
 #include "bn_lcl.h"
 #include "cryptlib.h"
 
+
 #define BN_NIST_192_TOP	(192+BN_BITS2-1)/BN_BITS2
 #define BN_NIST_224_TOP	(224+BN_BITS2-1)/BN_BITS2
 #define BN_NIST_256_TOP	(256+BN_BITS2-1)/BN_BITS2
 #define BN_NIST_384_TOP	(384+BN_BITS2-1)/BN_BITS2
 #define BN_NIST_521_TOP	(521+BN_BITS2-1)/BN_BITS2
 
+/* pre-computed tables are "carry-less" values of modulus*(i+1) */
 #if BN_BITS2 == 64
-const static BN_ULONG _nist_p_192[] = {0xFFFFFFFFFFFFFFFF,0xFFFFFFFFFFFFFFFE,
-	0xFFFFFFFFFFFFFFFF};
-const static BN_ULONG _nist_p_224[] = {0x0000000000000001,0xFFFFFFFF00000000,
-	0xFFFFFFFFFFFFFFFF,0x00000000FFFFFFFF};
-const static BN_ULONG _nist_p_256[] = {0xFFFFFFFFFFFFFFFF,0x00000000FFFFFFFF,
-	0x0000000000000000,0xFFFFFFFF00000001};
-const static BN_ULONG _nist_p_384[] = {0x00000000FFFFFFFF,0xFFFFFFFF00000000,
-	0xFFFFFFFFFFFFFFFE,0xFFFFFFFFFFFFFFFF,0xFFFFFFFFFFFFFFFF,
-	0xFFFFFFFFFFFFFFFF};
-const static BN_ULONG _nist_p_521[] = {0xFFFFFFFFFFFFFFFF,0xFFFFFFFFFFFFFFFF,
-	0xFFFFFFFFFFFFFFFF,0xFFFFFFFFFFFFFFFF,0xFFFFFFFFFFFFFFFF,
-	0xFFFFFFFFFFFFFFFF,0xFFFFFFFFFFFFFFFF,0xFFFFFFFFFFFFFFFF,
-	0x00000000000001FF};
+static const BN_ULONG _nist_p_192[][BN_NIST_192_TOP] = {
+	{0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFEULL,0xFFFFFFFFFFFFFFFFULL},
+	{0xFFFFFFFFFFFFFFFEULL,0xFFFFFFFFFFFFFFFDULL,0xFFFFFFFFFFFFFFFFULL},
+	{0xFFFFFFFFFFFFFFFDULL,0xFFFFFFFFFFFFFFFCULL,0xFFFFFFFFFFFFFFFFULL}
+	};
+static const BN_ULONG _nist_p_224[][BN_NIST_224_TOP] = {
+	{0x0000000000000001ULL,0xFFFFFFFF00000000ULL,
+	 0xFFFFFFFFFFFFFFFFULL,0x00000000FFFFFFFFULL},
+	{0x0000000000000002ULL,0xFFFFFFFE00000000ULL,
+	 0xFFFFFFFFFFFFFFFFULL,0x00000001FFFFFFFFULL} /* this one is "carry-full" */
+	};
+static const BN_ULONG _nist_p_256[][BN_NIST_256_TOP] = {
+	{0xFFFFFFFFFFFFFFFFULL,0x00000000FFFFFFFFULL,
+	 0x0000000000000000ULL,0xFFFFFFFF00000001ULL},
+	{0xFFFFFFFFFFFFFFFEULL,0x00000001FFFFFFFFULL,
+	 0x0000000000000000ULL,0xFFFFFFFE00000002ULL},
+	{0xFFFFFFFFFFFFFFFDULL,0x00000002FFFFFFFFULL,
+	 0x0000000000000000ULL,0xFFFFFFFD00000003ULL},
+	{0xFFFFFFFFFFFFFFFCULL,0x00000003FFFFFFFFULL,
+	 0x0000000000000000ULL,0xFFFFFFFC00000004ULL},
+	{0xFFFFFFFFFFFFFFFBULL,0x00000004FFFFFFFFULL,
+	 0x0000000000000000ULL,0xFFFFFFFB00000005ULL},
+	};
+static const BN_ULONG _nist_p_384[][BN_NIST_384_TOP] = {
+	{0x00000000FFFFFFFFULL,0xFFFFFFFF00000000ULL,0xFFFFFFFFFFFFFFFEULL,
+	 0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL},
+	{0x00000001FFFFFFFEULL,0xFFFFFFFE00000000ULL,0xFFFFFFFFFFFFFFFDULL,
+	 0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL},
+	{0x00000002FFFFFFFDULL,0xFFFFFFFD00000000ULL,0xFFFFFFFFFFFFFFFCULL,
+	 0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL},
+	{0x00000003FFFFFFFCULL,0xFFFFFFFC00000000ULL,0xFFFFFFFFFFFFFFFBULL,
+	 0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL},
+	{0x00000004FFFFFFFBULL,0xFFFFFFFB00000000ULL,0xFFFFFFFFFFFFFFFAULL,
+	 0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL},
+	};
+static const BN_ULONG _nist_p_521[] =
+	{0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
+	0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
+	0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
+	0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
+	0x00000000000001FFULL};
 #elif BN_BITS2 == 32
-const static BN_ULONG _nist_p_192[] = {0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFE,
-	0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF};
-const static BN_ULONG _nist_p_224[] = {0x00000001,0x00000000,0x00000000,
-	0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF};
-const static BN_ULONG _nist_p_256[] = {0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
-	0x00000000,0x00000000,0x00000000,0x00000001,0xFFFFFFFF};
-const static BN_ULONG _nist_p_384[] = {0xFFFFFFFF,0x00000000,0x00000000,
-	0xFFFFFFFF,0xFFFFFFFE,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
-	0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF};
-const static BN_ULONG _nist_p_521[] = {0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
+static const BN_ULONG _nist_p_192[][BN_NIST_192_TOP] = {
+	{0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFE,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
+	{0xFFFFFFFE,0xFFFFFFFF,0xFFFFFFFD,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
+	{0xFFFFFFFD,0xFFFFFFFF,0xFFFFFFFC,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF}
+	};
+static const BN_ULONG _nist_p_224[][BN_NIST_224_TOP] = {
+	{0x00000001,0x00000000,0x00000000,0xFFFFFFFF,
+	 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
+	{0x00000002,0x00000000,0x00000000,0xFFFFFFFE,
+	 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF}
+	};
+static const BN_ULONG _nist_p_256[][BN_NIST_256_TOP] = {
+	{0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0x00000000,
+	 0x00000000,0x00000000,0x00000001,0xFFFFFFFF},
+	{0xFFFFFFFE,0xFFFFFFFF,0xFFFFFFFF,0x00000001,
+	 0x00000000,0x00000000,0x00000002,0xFFFFFFFE},
+	{0xFFFFFFFD,0xFFFFFFFF,0xFFFFFFFF,0x00000002,
+	 0x00000000,0x00000000,0x00000003,0xFFFFFFFD},
+	{0xFFFFFFFC,0xFFFFFFFF,0xFFFFFFFF,0x00000003,
+	 0x00000000,0x00000000,0x00000004,0xFFFFFFFC},
+	{0xFFFFFFFB,0xFFFFFFFF,0xFFFFFFFF,0x00000004,
+	 0x00000000,0x00000000,0x00000005,0xFFFFFFFB},
+	};
+static const BN_ULONG _nist_p_384[][BN_NIST_384_TOP] = {
+	{0xFFFFFFFF,0x00000000,0x00000000,0xFFFFFFFF,0xFFFFFFFE,0xFFFFFFFF,
+	 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
+	{0xFFFFFFFE,0x00000001,0x00000000,0xFFFFFFFE,0xFFFFFFFD,0xFFFFFFFF,
+	 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
+	{0xFFFFFFFD,0x00000002,0x00000000,0xFFFFFFFD,0xFFFFFFFC,0xFFFFFFFF,
+	 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
+	{0xFFFFFFFC,0x00000003,0x00000000,0xFFFFFFFC,0xFFFFFFFB,0xFFFFFFFF,
+	 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
+	{0xFFFFFFFB,0x00000004,0x00000000,0xFFFFFFFB,0xFFFFFFFA,0xFFFFFFFF,
+	 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
+	};
+static const BN_ULONG _nist_p_521[] = {0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
 	0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
 	0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
 	0xFFFFFFFF,0x000001FF};
-#elif BN_BITS2 == 16
-const static BN_ULONG _nist_p_192[] = {0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFE,
-	0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF};
-const static BN_ULONG _nist_p_224[] = {0x0001,0x0000,0x0000,0x0000,0x0000,
-	0x0000,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF};
-const static BN_ULONG _nist_p_256[] = {0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,
-	0xFFFF,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0001,0x0000,0xFFFF,
-	0xFFFF};
-const static BN_ULONG _nist_p_384[] = {0xFFFF,0xFFFF,0x0000,0x0000,0x0000,
-	0x0000,0xFFFF,0xFFFF,0xFFFE,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,
-	0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF};
-const static BN_ULONG _nist_p_521[] = {0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,
-	0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,
-	0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,
-	0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0x01FF};
-#elif BN_BITS2 == 8
-const static BN_ULONG _nist_p_192[] = {0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-	0xFE,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-	0xFF,0xFF};
-const static BN_ULONG _nist_p_224[] = {0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
-	0x00,0x00,0x00,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-	0xFF,0xFF,0xFF,0xFF,0xFF,0xFF};
-const static BN_ULONG _nist_p_256[] = {0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-	0xFF,0xFF,0xFF,0xFF,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
-	0x00,0x00,0x01,0x00,0x00,0x00,0xFF,0xFF,0xFF,0xFF};
-const static BN_ULONG _nist_p_384[] = {0xFF,0xFF,0xFF,0xFF,0x00,0x00,0x00,0x00,
-	0x00,0x00,0x00,0x00,0xFF,0xFF,0xFF,0xFF,0xFE,0xFF,0xFF,0xFF,0xFF,0xFF,
-	0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-	0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF};
-const static BN_ULONG _nist_p_521[] = {0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-	0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-	0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-	0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-	0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-	0xFF,0x01};
+#else
+#error "unsupported BN_BITS2"
 #endif
 
-static const BIGNUM_C bn_nist_p_192 =
-	{ _nist_p_192, BN_NIST_192_TOP, BN_NIST_192_TOP, 0, BN_FLG_STATIC_DATA };
-static const BIGNUM_C bn_nist_p_224 =
-	{ _nist_p_224, BN_NIST_224_TOP, BN_NIST_224_TOP, 0, BN_FLG_STATIC_DATA };
-static const BIGNUM_C bn_nist_p_256 =
-	{ _nist_p_256, BN_NIST_256_TOP, BN_NIST_256_TOP, 0, BN_FLG_STATIC_DATA };
-static const BIGNUM_C bn_nist_p_384 =
-	{ _nist_p_384, BN_NIST_384_TOP, BN_NIST_384_TOP, 0, BN_FLG_STATIC_DATA };
-static const BIGNUM_C bn_nist_p_521 =
-	{ _nist_p_521, BN_NIST_521_TOP, BN_NIST_521_TOP, 0, BN_FLG_STATIC_DATA };
+
+static const BIGNUM _bignum_nist_p_192 =
+	{
+	(BN_ULONG *)_nist_p_192[0],
+	BN_NIST_192_TOP,
+	BN_NIST_192_TOP,
+	0,
+	BN_FLG_STATIC_DATA
+	};
+
+static const BIGNUM _bignum_nist_p_224 =
+	{
+	(BN_ULONG *)_nist_p_224[0],
+	BN_NIST_224_TOP,
+	BN_NIST_224_TOP,
+	0,
+	BN_FLG_STATIC_DATA
+	};
+
+static const BIGNUM _bignum_nist_p_256 =
+	{
+	(BN_ULONG *)_nist_p_256[0],
+	BN_NIST_256_TOP,
+	BN_NIST_256_TOP,
+	0,
+	BN_FLG_STATIC_DATA
+	};
+
+static const BIGNUM _bignum_nist_p_384 =
+	{
+	(BN_ULONG *)_nist_p_384[0],
+	BN_NIST_384_TOP,
+	BN_NIST_384_TOP,
+	0,
+	BN_FLG_STATIC_DATA
+	};
+
+static const BIGNUM _bignum_nist_p_521 =
+	{
+	(BN_ULONG *)_nist_p_521,
+	BN_NIST_521_TOP,
+	BN_NIST_521_TOP,
+	0,
+	BN_FLG_STATIC_DATA
+	};
+
 
 const BIGNUM *BN_get0_nist_prime_192(void)
 	{
-	return BIGNUM_CONST(&bn_nist_p_192);
+	return &_bignum_nist_p_192;
 	}
 
 const BIGNUM *BN_get0_nist_prime_224(void)
 	{
-	return BIGNUM_CONST(&bn_nist_p_224);
+	return &_bignum_nist_p_224;
 	}
 
 const BIGNUM *BN_get0_nist_prime_256(void)
 	{
-	return BIGNUM_CONST(&bn_nist_p_256);
+	return &_bignum_nist_p_256;
 	}
 
 const BIGNUM *BN_get0_nist_prime_384(void)
 	{
-	return BIGNUM_CONST(&bn_nist_p_384);
+	return &_bignum_nist_p_384;
 	}
 
 const BIGNUM *BN_get0_nist_prime_521(void)
 	{
-	return BIGNUM_CONST(&bn_nist_p_521);
+	return &_bignum_nist_p_521;
 	}
 
-/* some misc internal functions */
-static BN_ULONG _256_data[BN_NIST_256_TOP*6];
-static int _is_set_256_data = 0;
-static void _init_256_data(void);
 
-static BN_ULONG _384_data[BN_NIST_384_TOP*8];
-static int _is_set_384_data = 0;
-static void _init_384_data(void);
+static void nist_cp_bn_0(BN_ULONG *buf, BN_ULONG *a, int top, int max)
+	{
+	int i;
+	BN_ULONG *_tmp1 = (buf), *_tmp2 = (a);
+
+	OPENSSL_assert(top <= max);
+	for (i = (top); i != 0; i--)
+		*_tmp1++ = *_tmp2++;
+	for (i = (max) - (top); i != 0; i--)
+		*_tmp1++ = (BN_ULONG) 0;
+	}
+
+static void nist_cp_bn(BN_ULONG *buf, BN_ULONG *a, int top)
+	{ 
+	int i;
+	BN_ULONG *_tmp1 = (buf), *_tmp2 = (a);
+	for (i = (top); i != 0; i--)
+		*_tmp1++ = *_tmp2++;
+	}
 
-#define BN_NIST_ADD_ONE(a)	while (!(++(*(a)))) ++(a);
-#define __buf_0			(BN_ULONG)0
-#define __buf_0_1		(BN_ULONG)0
-#define __buf_0_2		(BN_ULONG)0
 #if BN_BITS2 == 64
-#define BN_64_BIT_BUF(n)	BN_ULONG __buf_##n = (BN_ULONG)0;
-#define BN_CP_64_TO_BUF(n)	__buf_##n = (a)[(n)];
-#define BN_CP_64_FROM_BUF(a,n)	*(a)++ = __buf_##n;
-#define BN_CASE_64_BIT(n,a)	case (n): __buf_##n = (a)[(n)];
-#if	UINT_MAX == 4294967295UL
-#define	nist32	unsigned int
-#define BN_32_BIT_BUF(n)	nist32 __buf_##n = (nist32)0;
-#define BN_CP_32_TO_BUF(n)	__buf_##n = ((nist32 *)(a))[(n)];
-#define BN_CP_32_FROM_BUF(a,n)	*((nist32)(a))++ = __buf_##n;
-#define BN_CASE_32_BIT(n,a)	case (n): __buf_##n = ((nist32)(a))[(n)];
-#elif	ULONG_MAX == 4294967295UL
-#define	nist32	unsigned long
-#define BN_32_BIT_BUF(n)	nist32 __buf_##n = (nist32)0;
-#define BN_CP_32_TO_BUF(n)	__buf_##n = ((nist32 *)(a))[(n)];
-#define BN_CP_32_FROM_BUF(a,n)	*((nist32)(a))++ = __buf_##n;
-#define BN_CASE_32_BIT(n,a)	case (n): __buf_##n = ((nist32)(a))[(n)];
+#define bn_cp_64(to, n, from, m)	(to)[n] = (m>=0)?((from)[m]):0;
+#define bn_64_set_0(to, n)		(to)[n] = (BN_ULONG)0;
+/*
+ * two following macros are implemented under assumption that they
+ * are called in a sequence with *ascending* n, i.e. as they are...
+ */
+#define bn_cp_32_naked(to, n, from, m)	(((n)&1)?(to[(n)/2]|=((m)&1)?(from[(m)/2]&BN_MASK2h):(from[(m)/2]<<32))\
+						:(to[(n)/2] =((m)&1)?(from[(m)/2]>>32):(from[(m)/2]&BN_MASK2l)))
+#define bn_32_set_0(to, n)		(((n)&1)?(to[(n)/2]&=BN_MASK2l):(to[(n)/2]=0));
+#define bn_cp_32(to,n,from,m)		((m)>=0)?bn_cp_32_naked(to,n,from,m):bn_32_set_0(to,n)
 #else
-#define	NO_32_BIT_TYPE
-#endif
-#elif BN_BITS2 == 32
-#define BN_64_BIT_BUF(n)	BN_ULONG __buf_##n##_1 = (BN_ULONG)0;\
-				BN_ULONG __buf_##n##_2 = (BN_ULONG)0;
-#define BN_CP_64_TO_BUF(n)	__buf_##n##_2 = (a)[2*(n)+1];\
-				__buf_##n##_1 = (a)[2*(n)];
-#define BN_CP_64_FROM_BUF(a,n)	*(a)++ = __buf_##n##_1;\
-				*(a)++ = __buf_##n##_2;
-#define BN_CASE_64_BIT(n,a)	case 2*(n)+1: __buf_##n##_2 = (a)[2*(n)+1];\
-				case 2*(n):   __buf_##n##_1 = (a)[2*(n)];
-				
-#define BN_32_BIT_BUF(n)	BN_ULONG __buf_##n = (BN_ULONG)0;
-#define BN_CP_32_TO_BUF(n)	__buf_##n = (a)[(n)];
-#define BN_CP_32_FROM_BUF(a,n)	*(a)++ = __buf_##n;
-#define BN_CASE_32_BIT(n,a)	case (n): __buf_##n = (a)[(n)];
-#elif BN_BITS2 == 16
-#define __buf_0_3		(BN_ULONG)0
-#define __buf_0_4		(BN_ULONG)0
-#define BN_64_BIT_BUF(n)	BN_ULONG __buf_##n##_1 = (BN_ULONG)0;\
-				BN_ULONG __buf_##n##_2 = (BN_ULONG)0;\
-				BN_ULONG __buf_##n##_3 = (BN_ULONG)0;\
-				BN_ULONG __buf_##n##_4 = (BN_ULONG)0;
-#define BN_CP_64_TO_BUF(n)	__buf_##n##_4 = (a)[4*(n)+3];\
-				__buf_##n##_3 = (a)[4*(n)+2];\
-				__buf_##n##_2 = (a)[4*(n)+1];\
-				__buf_##n##_1 = (a)[4*(n)];
-#define BN_CP_64_FROM_BUF(a,n)	*(a)++ = __buf_##n##_1;\
-				*(a)++ = __buf_##n##_2;\
-				*(a)++ = __buf_##n##_3;\
-				*(a)++ = __buf_##n##_4;
-#define BN_CASE_64_BIT(n,a)	case 4*(n)+3: __buf_##n##_4 = (a)[4*(n)+3];\
-				case 4*(n)+2: __buf_##n##_3 = (a)[4*(n)+2];\
-				case 4*(n)+1: __buf_##n##_2 = (a)[4*(n)+1];\
-				case 4*(n):   __buf_##n##_1 = (a)[4*(n)];
-#define BN_32_BIT_BUF(n)	BN_ULONG __buf_##n##_1 = (BN_ULONG)0;\
-				BN_ULONG __buf_##n##_2 = (BN_ULONG)0;
-#define BN_CP_32_TO_BUF(n)	__buf_##n##_1 = (a)[2*(n)];\
-				__buf_##n##_2 = (a)[2*(n)+1];
-#define BN_CP_32_FROM_BUF(a,n)	*(a)++ = __buf_##n##_1;\
-				*(a)++ = __buf_##n##_2;
-#define BN_CASE_32_BIT(n,a)	case 2*(n)+1: __buf_##n##_2 = (a)[2*(n)+1];\
-				case 2*(n):   __buf_##n##_1 = (a)[2*(n)];
-#elif BN_BITS2 == 8
-#define __buf_0_3		(BN_ULONG)0
-#define __buf_0_4		(BN_ULONG)0
-#define __buf_0_5		(BN_ULONG)0
-#define __buf_0_6		(BN_ULONG)0
-#define __buf_0_7		(BN_ULONG)0
-#define __buf_0_8		(BN_ULONG)0
-#define BN_64_BIT_BUF(n)	BN_ULONG __buf_##n##_1 = (BN_ULONG)0;\
-				BN_ULONG __buf_##n##_2 = (BN_ULONG)0;\
-				BN_ULONG __buf_##n##_3 = (BN_ULONG)0;\
-				BN_ULONG __buf_##n##_4 = (BN_ULONG)0;\
-				BN_ULONG __buf_##n##_5 = (BN_ULONG)0;\
-				BN_ULONG __buf_##n##_6 = (BN_ULONG)0;\
-				BN_ULONG __buf_##n##_7 = (BN_ULONG)0;\
-				BN_ULONG __buf_##n##_8 = (BN_ULONG)0;
-#define BN_CP_64_TO_BUF(n)	__buf_##n##_8 = (a)[8*(n)+7];\
-				__buf_##n##_7 = (a)[8*(n)+6];\
-				__buf_##n##_6 = (a)[8*(n)+5];\
-				__buf_##n##_5 = (a)[8*(n)+4];\
-				__buf_##n##_4 = (a)[8*(n)+3];\
-				__buf_##n##_3 = (a)[8*(n)+2];\
-				__buf_##n##_2 = (a)[8*(n)+1];\
-				__buf_##n##_1 = (a)[8*(n)];
-#define BN_CP_64_FROM_BUF(a,n)	*(a)++ = __buf_##n##_1;\
-				*(a)++ = __buf_##n##_2;\
-				*(a)++ = __buf_##n##_3;\
-				*(a)++ = __buf_##n##_4;\
-				*(a)++ = __buf_##n##_5;\
-				*(a)++ = __buf_##n##_6;\
-				*(a)++ = __buf_##n##_7;\
-				*(a)++ = __buf_##n##_8;
-#define BN_CASE_64_BIT(n,a)	case 8*(n)+7: __buf_##n##_8 = (a)[8*(n)+7];\
-				case 8*(n)+6: __buf_##n##_7 = (a)[8*(n)+6];\
-				case 8*(n)+5: __buf_##n##_6 = (a)[8*(n)+5];\
-				case 8*(n)+4: __buf_##n##_5 = (a)[8*(n)+4];\
-				case 8*(n)+3: __buf_##n##_4 = (a)[8*(n)+3];\
-				case 8*(n)+2: __buf_##n##_3 = (a)[8*(n)+2];\
-				case 8*(n)+1: __buf_##n##_2 = (a)[8*(n)+1];\
-				case 8*(n):   __buf_##n##_1 = (a)[8*(n)];
-#define BN_32_BIT_BUF(n)	BN_ULONG __buf_##n##_1 = (BN_ULONG)0;\
-				BN_ULONG __buf_##n##_2 = (BN_ULONG)0;\
-				BN_ULONG __buf_##n##_3 = (BN_ULONG)0;\
-				BN_ULONG __buf_##n##_4 = (BN_ULONG)0;
-#define BN_CP_32_TO_BUF(n)	__buf_##n##_1 = (a)[4*(n)];\
-				__buf_##n##_2 = (a)[4*(n)+1];\
-				__buf_##n##_3 = (a)[4*(n)+2];\
-				__buf_##n##_4 = (a)[4*(n)+3];
-#define BN_CP_32_FROM_BUF(a,n)	*(a)++ = __buf_##n##_1;\
-				*(a)++ = __buf_##n##_2;\
-				*(a)++ = __buf_##n##_3;\
-				*(a)++ = __buf_##n##_4;
-#define BN_CASE_32_BIT(n,a)	case 4*(n)+3: __buf_##n##_4 = (a)[4*(n)+3];\
-				case 4*(n)+2: __buf_##n##_3 = (a)[4*(n)+2];\
-				case 4*(n)+1: __buf_##n##_2 = (a)[4*(n)+1];\
-				case 4*(n):   __buf_##n##_1 = (a)[4*(n)];
+#define bn_cp_64(to, n, from, m) \
+	{ \
+	bn_cp_32(to, (n)*2, from, (m)*2); \
+	bn_cp_32(to, (n)*2+1, from, (m)*2+1); \
+	}
+#define bn_64_set_0(to, n) \
+	{ \
+	bn_32_set_0(to, (n)*2); \
+	bn_32_set_0(to, (n)*2+1); \
+	}
+#if BN_BITS2 == 32
+#define bn_cp_32(to, n, from, m)	(to)[n] = (m>=0)?((from)[m]):0;
+#define bn_32_set_0(to, n)		(to)[n] = (BN_ULONG)0;
 #endif
+#endif /* BN_BITS2 != 64 */
 
 
-#define BN_192_SET(d,a1,a2,a3) \
-	{\
-	register BN_ULONG *td = (d);\
-	BN_CP_64_FROM_BUF(td,a3); BN_CP_64_FROM_BUF(td,a2);\
-	BN_CP_64_FROM_BUF(td,a1);\
+#define nist_set_192(to, from, a1, a2, a3) \
+	{ \
+	bn_cp_64(to, 0, from, (a3) - 3) \
+	bn_cp_64(to, 1, from, (a2) - 3) \
+	bn_cp_64(to, 2, from, (a1) - 3) \
 	}
 
 int BN_nist_mod_192(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 	BN_CTX *ctx)
 	{
-	int      top;
-	BN_ULONG carry = 0;
-	register BN_ULONG *r_d, *a_d;
-	BN_ULONG t_d[BN_NIST_192_TOP];
-	BN_64_BIT_BUF(3)  BN_64_BIT_BUF(4)
-	BN_64_BIT_BUF(5)
-
-	top = BN_ucmp(field, a);
-	if (top == 0)
-		return BN_zero(r);
-	else if (top > 0)
-		return (r == a)? 1 : (BN_copy(r ,a) != NULL);
+	int      top = a->top, i;
+	int      carry;
+	register BN_ULONG *r_d, *a_d = a->d;
+	BN_ULONG t_d[BN_NIST_192_TOP],
+	         buf[BN_NIST_192_TOP],
+		 c_d[BN_NIST_192_TOP],
+		*res;
+	size_t   mask;
+
+	field = &_bignum_nist_p_192; /* just to make sure */
+
+ 	if (BN_is_negative(a) || a->top > 2*BN_NIST_192_TOP)
+		return BN_nnmod(r, field, a, ctx);
+
+	i = BN_ucmp(field, a);
+	if (i == 0)
+		{
+		BN_zero(r);
+		return 1;
+		}
+	else if (i > 0)
+		return (r == a) ? 1 : (BN_copy(r ,a) != NULL);
 
 	if (r != a)
-		if (!BN_ncopy(r, a, BN_NIST_192_TOP))
-			return 0;
-
-	r_d = r->d;
-	a_d = a->d;
-	top = a->top-1;
-
-	switch (top)
 		{
-		BN_CASE_64_BIT(5, a_d)
-		BN_CASE_64_BIT(4, a_d)
-		BN_CASE_64_BIT(3, a_d)
-			break;
-		default: /* a->top == field->top */
-			return BN_usub(r, a, field);
+		if (!bn_wexpand(r, BN_NIST_192_TOP))
+			return 0;
+		r_d = r->d;
+		nist_cp_bn(r_d, a_d, BN_NIST_192_TOP);
 		}
+	else
+		r_d = a_d;
 
-	BN_192_SET(t_d,0,3,3)
-	if (bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP))
-		++carry;
-
-	BN_192_SET(t_d,4,4,0)
-	if (bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP))
-		++carry;
+	nist_cp_bn_0(buf, a_d + BN_NIST_192_TOP, top - BN_NIST_192_TOP, BN_NIST_192_TOP);
 
-	BN_192_SET(t_d,5,5,5)
-	if (bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP))
-		++carry;
+	nist_set_192(t_d, buf, 0, 3, 3);
+	carry = bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP);
+	nist_set_192(t_d, buf, 4, 4, 0);
+	carry += bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP);
+	nist_set_192(t_d, buf, 5, 5, 5)
+	carry += bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP);
 
-	while (carry)
-		{
-		if (bn_sub_words(r_d, r_d, _nist_p_192, BN_NIST_192_TOP))
-			--carry; 
-		}
+	if (carry > 0)
+		carry = bn_sub_words(r_d,r_d,_nist_p_192[carry-1],BN_NIST_192_TOP);
+	else
+		carry = 1;
+
+	/*
+	 * we need 'if (carry==0 || result>=modulus) result-=modulus;'
+	 * as comparison implies subtraction, we can write
+	 * 'tmp=result-modulus; if (!carry || !borrow) result=tmp;'
+	 * this is what happens below, but without explicit if:-) a.
+	 */
+	mask  = 0-(size_t)bn_sub_words(c_d,r_d,_nist_p_192[0],BN_NIST_192_TOP);
+	mask &= 0-(size_t)carry;
+	res   = (BN_ULONG *)(((size_t)c_d&~mask) | ((size_t)r_d&mask));
+	nist_cp_bn(r_d, res, BN_NIST_192_TOP);
 	r->top = BN_NIST_192_TOP;
-
-#if 1
-	bn_clear_top2max(r);
-#endif
 	bn_correct_top(r);
 
-	if (BN_ucmp(r, field) >= 0)
+	if (BN_ucmp(field, r) <= 0)
 		{
-		bn_sub_words(r_d, r_d, _nist_p_192, BN_NIST_192_TOP);
-		bn_correct_top(r);
+		if (!BN_usub(r, r, field)) return 0;
 		}
 
-	bn_check_top(r);
 	return 1;
 	}
 
-#define BN_224_SET(d,a1,a2,a3,a4,a5,a6,a7) \
-	{\
-	register BN_ULONG *td = (d);\
-	BN_CP_32_FROM_BUF(td,a7); BN_CP_32_FROM_BUF(td,a6);\
-	BN_CP_32_FROM_BUF(td,a5); BN_CP_32_FROM_BUF(td,a4);\
-	BN_CP_32_FROM_BUF(td,a3); BN_CP_32_FROM_BUF(td,a2);\
-	BN_CP_32_FROM_BUF(td,a1);\
+typedef BN_ULONG (*bn_addsub_f)(BN_ULONG *,const BN_ULONG *,const BN_ULONG *,int);
+
+#define nist_set_224(to, from, a1, a2, a3, a4, a5, a6, a7) \
+	{ \
+	bn_cp_32(to, 0, from, (a7) - 7) \
+	bn_cp_32(to, 1, from, (a6) - 7) \
+	bn_cp_32(to, 2, from, (a5) - 7) \
+	bn_cp_32(to, 3, from, (a4) - 7) \
+	bn_cp_32(to, 4, from, (a3) - 7) \
+	bn_cp_32(to, 5, from, (a2) - 7) \
+	bn_cp_32(to, 6, from, (a1) - 7) \
 	}
 
 int BN_nist_mod_224(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 	BN_CTX *ctx)
 	{
-#ifndef NO_32_BIT_TYPE
-	int	tmp_int;
-	int	carry = 0;
-	BN_ULONG *r_d, *a_d;
-	BN_ULONG t_d[BN_NIST_224_TOP];
-	BN_32_BIT_BUF(7)  BN_32_BIT_BUF(8)
-	BN_32_BIT_BUF(9)  BN_32_BIT_BUF(10)
-	BN_32_BIT_BUF(11) BN_32_BIT_BUF(12)
-	BN_32_BIT_BUF(13)
-
-	tmp_int = BN_ucmp(field, a);
-	if (tmp_int == 0)
-		return BN_zero(r);
-	else if (tmp_int > 0)
+	int	top = a->top, i;
+	int	carry;
+	BN_ULONG *r_d, *a_d = a->d;
+	BN_ULONG t_d[BN_NIST_224_TOP],
+	         buf[BN_NIST_224_TOP],
+		 c_d[BN_NIST_224_TOP],
+		*res;
+	size_t   mask;
+	union { bn_addsub_f f; size_t p; } u;
+
+	field = &_bignum_nist_p_224; /* just to make sure */
+
+ 	if (BN_is_negative(a) || a->top > 2*BN_NIST_224_TOP)
+		return BN_nnmod(r, field, a, ctx);
+
+	i = BN_ucmp(field, a);
+	if (i == 0)
+		{
+		BN_zero(r);
+		return 1;
+		}
+	else if (i > 0)
 		return (r == a)? 1 : (BN_copy(r ,a) != NULL);
 
 	if (r != a)
-		if (!BN_ncopy(r, a, BN_NIST_224_TOP))
-			return 0;
-
-	r_d = r->d;
-	a_d = a->d;
-
-	tmp_int = a->top-1;
-
-	switch (tmp_int)
 		{
-		BN_CASE_32_BIT(13, a_d)
-		BN_CASE_32_BIT(12, a_d)
-		BN_CASE_32_BIT(11, a_d)
-		BN_CASE_32_BIT(10, a_d)
-		BN_CASE_32_BIT(9,  a_d)
-		BN_CASE_32_BIT(8,  a_d)
-		BN_CASE_32_BIT(7,  a_d)
-			break;
-		default: /* a->top == field->top */
-			return BN_usub(r, a, field);
+		if (!bn_wexpand(r, BN_NIST_224_TOP))
+			return 0;
+		r_d = r->d;
+		nist_cp_bn(r_d, a_d, BN_NIST_224_TOP);
 		}
-
-	BN_224_SET(t_d,10,9,8,7,0,0,0)
-	if (bn_add_words(r_d, r_d, t_d, BN_NIST_224_TOP))
-		++carry;
-	BN_224_SET(t_d,0,13,12,11,0,0,0)
-	if (bn_add_words(r_d, r_d, t_d, BN_NIST_224_TOP))
-		++carry;
-	BN_224_SET(t_d,13,12,11,10,9,8,7)
-	if (bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP))
-		--carry;
-	BN_224_SET(t_d,0,0,0,0,13,12,11)
-	if (bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP))
-		--carry;
-
+	else
+		r_d = a_d;
+
+#if BN_BITS2==64
+	/* copy upper 256 bits of 448 bit number ... */
+	nist_cp_bn_0(t_d, a_d + (BN_NIST_224_TOP-1), top - (BN_NIST_224_TOP-1), BN_NIST_224_TOP);
+	/* ... and right shift by 32 to obtain upper 224 bits */
+	nist_set_224(buf, t_d, 14, 13, 12, 11, 10, 9, 8);
+	/* truncate lower part to 224 bits too */
+	r_d[BN_NIST_224_TOP-1] &= BN_MASK2l;
+#else
+	nist_cp_bn_0(buf, a_d + BN_NIST_224_TOP, top - BN_NIST_224_TOP, BN_NIST_224_TOP);
+#endif
+	nist_set_224(t_d, buf, 10, 9, 8, 7, 0, 0, 0);
+	carry = bn_add_words(r_d, r_d, t_d, BN_NIST_224_TOP);
+	nist_set_224(t_d, buf, 0, 13, 12, 11, 0, 0, 0);
+	carry += bn_add_words(r_d, r_d, t_d, BN_NIST_224_TOP);
+	nist_set_224(t_d, buf, 13, 12, 11, 10, 9, 8, 7);
+	carry -= bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP);
+	nist_set_224(t_d, buf, 0, 0, 0, 0, 13, 12, 11);
+	carry -= bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP);
+
+#if BN_BITS2==64
+	carry = (int)(r_d[BN_NIST_224_TOP-1]>>32);
+#endif
+	u.f = bn_sub_words;
 	if (carry > 0)
-		while (carry)
-			{
-			if (bn_sub_words(r_d,r_d,_nist_p_224,BN_NIST_224_TOP))
-				--carry;
-			}
+		{
+		carry = bn_sub_words(r_d,r_d,_nist_p_224[carry-1],BN_NIST_224_TOP);
+#if BN_BITS2==64
+		carry=(int)(~(r_d[BN_NIST_224_TOP-1]>>32))&1;
+#endif
+		}
 	else if (carry < 0)
-		while (carry)
-			{
-			if (bn_add_words(r_d,r_d,_nist_p_224,BN_NIST_224_TOP))
-				++carry;
-			}
-
+		{
+		/* it's a bit more comlicated logic in this case.
+		 * if bn_add_words yields no carry, then result
+		 * has to be adjusted by unconditionally *adding*
+		 * the modulus. but if it does, then result has
+		 * to be compared to the modulus and conditionally
+		 * adjusted by *subtracting* the latter. */
+		carry = bn_add_words(r_d,r_d,_nist_p_224[-carry-1],BN_NIST_224_TOP);
+		mask = 0-(size_t)carry;
+		u.p = ((size_t)bn_sub_words&mask) | ((size_t)bn_add_words&~mask);
+		}
+	else
+		carry = 1;
+
+	/* otherwise it's effectively same as in BN_nist_mod_192... */
+	mask  = 0-(size_t)(*u.f)(c_d,r_d,_nist_p_224[0],BN_NIST_224_TOP);
+	mask &= 0-(size_t)carry;
+	res   = (BN_ULONG *)(((size_t)c_d&~mask) | ((size_t)r_d&mask));
+	nist_cp_bn(r_d, res, BN_NIST_224_TOP);
 	r->top = BN_NIST_224_TOP;
-#if 1
-	bn_clear_top2max(r);
-#endif
 	bn_correct_top(r);
 
-	if (BN_ucmp(r, field) >= 0)
+	if (BN_ucmp(field, r) <= 0)
 		{
-		bn_sub_words(r_d, r_d, _nist_p_224, BN_NIST_224_TOP);
-		bn_correct_top(r);
+		if (!BN_usub(r, r, field)) return 0;
 		}
-	bn_check_top(r);
-	return 1;
-#else
-	return 0;
-#endif
-	}
 
-static void _init_256_data(void)
-	{
-	int	i;
-	BN_ULONG *tmp1 = _256_data;
-	const BN_ULONG *tmp2 = tmp1;
-
-	memcpy(tmp1, _nist_p_256, BN_NIST_256_TOP * sizeof(BN_ULONG));
-	tmp1 += BN_NIST_256_TOP;
-
-	for (i=0; i<5; i++)
-		{
-		bn_add_words(tmp1, _nist_p_256, tmp2, BN_NIST_256_TOP);
-		tmp2  = tmp1;
-		tmp1 += BN_NIST_256_TOP;
-		}
-	_is_set_256_data = 1;
+	return 1;
 	}
 
-#define BN_256_SET(d,a1,a2,a3,a4,a5,a6,a7,a8) \
-	{\
-	register BN_ULONG *td = (d);\
-	BN_CP_32_FROM_BUF(td,a8); BN_CP_32_FROM_BUF(td,a7);\
-	BN_CP_32_FROM_BUF(td,a6); BN_CP_32_FROM_BUF(td,a5);\
-	BN_CP_32_FROM_BUF(td,a4); BN_CP_32_FROM_BUF(td,a3);\
-	BN_CP_32_FROM_BUF(td,a2); BN_CP_32_FROM_BUF(td,a1);\
+#define nist_set_256(to, from, a1, a2, a3, a4, a5, a6, a7, a8) \
+	{ \
+	bn_cp_32(to, 0, from, (a8) - 8) \
+	bn_cp_32(to, 1, from, (a7) - 8) \
+	bn_cp_32(to, 2, from, (a6) - 8) \
+	bn_cp_32(to, 3, from, (a5) - 8) \
+	bn_cp_32(to, 4, from, (a4) - 8) \
+	bn_cp_32(to, 5, from, (a3) - 8) \
+	bn_cp_32(to, 6, from, (a2) - 8) \
+	bn_cp_32(to, 7, from, (a1) - 8) \
 	}
 
 int BN_nist_mod_256(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 	BN_CTX *ctx)
 	{
-#ifndef NO_32_BIT_TYPE
-	int	tmp_int;
+	int	i, top = a->top;
 	int	carry = 0;
-	register BN_ULONG *a_d, *r_d;
-	BN_ULONG t_d[BN_NIST_256_TOP];
-	BN_ULONG t_d2[BN_NIST_256_TOP];
-	BN_32_BIT_BUF(8)  BN_32_BIT_BUF(9)
-	BN_32_BIT_BUF(10) BN_32_BIT_BUF(11)
-	BN_32_BIT_BUF(12) BN_32_BIT_BUF(13)
-	BN_32_BIT_BUF(14) BN_32_BIT_BUF(15)
-
-	if (!_is_set_256_data)
+	register BN_ULONG *a_d = a->d, *r_d;
+	BN_ULONG t_d[BN_NIST_256_TOP],
+	         buf[BN_NIST_256_TOP],
+		 c_d[BN_NIST_256_TOP],
+		*res;
+	size_t   mask;
+	union { bn_addsub_f f; size_t p; } u;
+
+	field = &_bignum_nist_p_256; /* just to make sure */
+
+ 	if (BN_is_negative(a) || a->top > 2*BN_NIST_256_TOP)
+		return BN_nnmod(r, field, a, ctx);
+
+	i = BN_ucmp(field, a);
+	if (i == 0)
 		{
-		CRYPTO_w_lock(CRYPTO_LOCK_BN);
-		
-		if (!_is_set_256_data)
-			_init_256_data();
-		
-		CRYPTO_w_unlock(CRYPTO_LOCK_BN);
+		BN_zero(r);
+		return 1;
 		}
-	
-	tmp_int = BN_ucmp(field, a);
-	if (tmp_int == 0)
-		return BN_zero(r);
-	else if (tmp_int > 0)
+	else if (i > 0)
 		return (r == a)? 1 : (BN_copy(r ,a) != NULL);
 
 	if (r != a)
-		if (!BN_ncopy(r, a, BN_NIST_256_TOP))
-			return 0;
-
-	tmp_int = a->top-1;
-
-	a_d = a->d;
-	r_d = r->d;
-	switch (tmp_int)
 		{
-		BN_CASE_32_BIT(15, a_d)
-		BN_CASE_32_BIT(14, a_d)
-		BN_CASE_32_BIT(13, a_d)
-		BN_CASE_32_BIT(12, a_d)
-		BN_CASE_32_BIT(11, a_d)
-		BN_CASE_32_BIT(10, a_d)
-		BN_CASE_32_BIT(9,  a_d)
-		BN_CASE_32_BIT(8,  a_d)
-			break;
-		default: /* a->top == field->top */
-			return BN_usub(r, a, field);
+		if (!bn_wexpand(r, BN_NIST_256_TOP))
+			return 0;
+		r_d = r->d;
+		nist_cp_bn(r_d, a_d, BN_NIST_256_TOP);
 		}
+	else
+		r_d = a_d;
+
+	nist_cp_bn_0(buf, a_d + BN_NIST_256_TOP, top - BN_NIST_256_TOP, BN_NIST_256_TOP);
 
 	/*S1*/
-	BN_256_SET(t_d,15,14,13,12,11,0,0,0)
+	nist_set_256(t_d, buf, 15, 14, 13, 12, 11, 0, 0, 0);
 	/*S2*/
-	BN_256_SET(t_d2,0,15,14,13,12,0,0,0)
-	if (bn_add_words(t_d, t_d, t_d2, BN_NIST_256_TOP))
-		carry = 2;
+	nist_set_256(c_d, buf, 0, 15, 14, 13, 12, 0, 0, 0);
+	carry = bn_add_words(t_d, t_d, c_d, BN_NIST_256_TOP);
 	/* left shift */
 		{
 		register BN_ULONG *ap,t,c;
 		ap = t_d;
 		c=0;
-		for (tmp_int=BN_NIST_256_TOP; tmp_int != 0; --tmp_int)
+		for (i = BN_NIST_256_TOP; i != 0; --i)
 			{
 			t= *ap;
 			*(ap++)=((t<<1)|c)&BN_MASK2;
 			c=(t & BN_TBIT)?1:0;
 			}
-		if (c)
-			++carry;
+		carry <<= 1;
+		carry  |= c;
 		}
-
-	if (bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP))
-		++carry;
+	carry += bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 	/*S3*/
-	BN_256_SET(t_d,15,14,0,0,0,10,9,8)
-	if (bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP))
-		++carry;
+	nist_set_256(t_d, buf, 15, 14, 0, 0, 0, 10, 9, 8);
+	carry += bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 	/*S4*/
-	BN_256_SET(t_d,8,13,15,14,13,11,10,9)
-	if (bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP))
-		++carry;
+	nist_set_256(t_d, buf, 8, 13, 15, 14, 13, 11, 10, 9);
+	carry += bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 	/*D1*/
-	BN_256_SET(t_d,10,8,0,0,0,13,12,11)
-	if (bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP))
-		--carry;
+	nist_set_256(t_d, buf, 10, 8, 0, 0, 0, 13, 12, 11);
+	carry -= bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 	/*D2*/
-	BN_256_SET(t_d,11,9,0,0,15,14,13,12)
-	if (bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP))
-		--carry;
+	nist_set_256(t_d, buf, 11, 9, 0, 0, 15, 14, 13, 12);
+	carry -= bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 	/*D3*/
-	BN_256_SET(t_d,12,0,10,9,8,15,14,13)
-	if (bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP))
-		--carry;
+	nist_set_256(t_d, buf, 12, 0, 10, 9, 8, 15, 14, 13);
+	carry -= bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 	/*D4*/
-	BN_256_SET(t_d,13,0,11,10,9,0,15,14)
-	if (bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP))
-		--carry;
-	
-	if (carry)
+	nist_set_256(t_d, buf, 13, 0, 11, 10, 9, 0, 15, 14);
+	carry -= bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
+
+	/* see BN_nist_mod_224 for explanation */
+	u.f = bn_sub_words;
+	if (carry > 0)
+		carry = bn_sub_words(r_d,r_d,_nist_p_256[carry-1],BN_NIST_256_TOP);
+	else if (carry < 0)
 		{
-		if (carry > 0)
-			bn_sub_words(r_d, r_d, _256_data + BN_NIST_256_TOP *
-				--carry, BN_NIST_256_TOP);
-		else
-			{
-			carry = -carry;
-			bn_add_words(r_d, r_d, _256_data + BN_NIST_256_TOP *
-				--carry, BN_NIST_256_TOP);
-			}
+		carry = bn_add_words(r_d,r_d,_nist_p_256[-carry-1],BN_NIST_256_TOP);
+		mask = 0-(size_t)carry;
+		u.p = ((size_t)bn_sub_words&mask) | ((size_t)bn_add_words&~mask);
 		}
+	else
+		carry = 1;
 
+	mask  = 0-(size_t)(*u.f)(c_d,r_d,_nist_p_256[0],BN_NIST_256_TOP);
+	mask &= 0-(size_t)carry;
+	res   = (BN_ULONG *)(((size_t)c_d&~mask) | ((size_t)r_d&mask));
+	nist_cp_bn(r_d, res, BN_NIST_256_TOP);
 	r->top = BN_NIST_256_TOP;
-#if 1
-	bn_clear_top2max(r);
-#endif
 	bn_correct_top(r);
 
-	if (BN_ucmp(r, field) >= 0)
+	if (BN_ucmp(field, r) <= 0)
 		{
-		bn_sub_words(r_d, r_d, _nist_p_256, BN_NIST_256_TOP);
-		bn_correct_top(r);
+		if (!BN_usub(r, r, field)) return 0;
 		}
-	bn_check_top(r);
-	return 1;
-#else
-	return 0;
-#endif
-	}
-
-static void _init_384_data(void)
-	{
-	int	i;
-	BN_ULONG *tmp1 = _384_data;
-	const BN_ULONG *tmp2 = tmp1;
 
-	memcpy(tmp1, _nist_p_384, BN_NIST_384_TOP * sizeof(BN_ULONG));
-	tmp1 += BN_NIST_384_TOP;
-
-	for (i=0; i<7; i++)
-		{
-		bn_add_words(tmp1, _nist_p_384, tmp2, BN_NIST_384_TOP);
-		tmp2  = tmp1;
-		tmp1 += BN_NIST_384_TOP;
-		}
-	_is_set_384_data = 1;
+	return 1;
 	}
 
-#define BN_384_SET(d,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12) \
-	{\
-	register BN_ULONG *td = (d);\
-	BN_CP_32_FROM_BUF(td,a12); BN_CP_32_FROM_BUF(td,a11);\
-	BN_CP_32_FROM_BUF(td,a10); BN_CP_32_FROM_BUF(td,a9);\
-	BN_CP_32_FROM_BUF(td,a8);  BN_CP_32_FROM_BUF(td,a7);\
-	BN_CP_32_FROM_BUF(td,a6);  BN_CP_32_FROM_BUF(td,a5);\
-	BN_CP_32_FROM_BUF(td,a4);  BN_CP_32_FROM_BUF(td,a3);\
-	BN_CP_32_FROM_BUF(td,a2);  BN_CP_32_FROM_BUF(td,a1);\
+#define nist_set_384(to,from,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12) \
+	{ \
+	bn_cp_32(to, 0, from,  (a12) - 12) \
+	bn_cp_32(to, 1, from,  (a11) - 12) \
+	bn_cp_32(to, 2, from,  (a10) - 12) \
+	bn_cp_32(to, 3, from,  (a9) - 12)  \
+	bn_cp_32(to, 4, from,  (a8) - 12)  \
+	bn_cp_32(to, 5, from,  (a7) - 12)  \
+	bn_cp_32(to, 6, from,  (a6) - 12)  \
+	bn_cp_32(to, 7, from,  (a5) - 12)  \
+	bn_cp_32(to, 8, from,  (a4) - 12)  \
+	bn_cp_32(to, 9, from,  (a3) - 12)  \
+	bn_cp_32(to, 10, from, (a2) - 12)  \
+	bn_cp_32(to, 11, from, (a1) - 12)  \
 	}
 
 int BN_nist_mod_384(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 	BN_CTX *ctx)
 	{
-#ifndef NO_32_BIT_TYPE
-	int	tmp_int;
+	int	i, top = a->top;
 	int	carry = 0;
-	register BN_ULONG *r_d, *a_d;
-	BN_ULONG t_d[BN_NIST_384_TOP];
-	BN_32_BIT_BUF(12) BN_32_BIT_BUF(13)
-	BN_32_BIT_BUF(14) BN_32_BIT_BUF(15)
-	BN_32_BIT_BUF(16) BN_32_BIT_BUF(17)
-	BN_32_BIT_BUF(18) BN_32_BIT_BUF(19)
-	BN_32_BIT_BUF(20) BN_32_BIT_BUF(21)
-	BN_32_BIT_BUF(22) BN_32_BIT_BUF(23)
-
-	if (!_is_set_384_data)
-		{
-		CRYPTO_w_lock(CRYPTO_LOCK_BN);
-		
-		if (!_is_set_384_data)
-			_init_384_data();
+	register BN_ULONG *r_d, *a_d = a->d;
+	BN_ULONG t_d[BN_NIST_384_TOP],
+	         buf[BN_NIST_384_TOP],
+		 c_d[BN_NIST_384_TOP],
+		*res;
+	size_t	 mask;
+	union { bn_addsub_f f; size_t p; } u;
 
-		CRYPTO_w_unlock(CRYPTO_LOCK_BN);
-		}
+	field = &_bignum_nist_p_384; /* just to make sure */
 
-	tmp_int = BN_ucmp(field, a);
-	if (tmp_int == 0)
-		return BN_zero(r);
-	else if (tmp_int > 0)
+ 	if (BN_is_negative(a) || a->top > 2*BN_NIST_384_TOP)
+		return BN_nnmod(r, field, a, ctx);
+
+	i = BN_ucmp(field, a);
+	if (i == 0)
+		{
+		BN_zero(r);
+		return 1;
+		}
+	else if (i > 0)
 		return (r == a)? 1 : (BN_copy(r ,a) != NULL);
 
 	if (r != a)
-		if (!BN_ncopy(r, a, BN_NIST_384_TOP))
-			return 0;
-
-	r_d = r->d;
-	a_d = a->d;
-	tmp_int = a->top-1;
-
-	switch (tmp_int)
 		{
-		BN_CASE_32_BIT(23, a_d)
-		BN_CASE_32_BIT(22, a_d)
-		BN_CASE_32_BIT(21, a_d)
-		BN_CASE_32_BIT(20, a_d)
-		BN_CASE_32_BIT(19, a_d)
-		BN_CASE_32_BIT(18, a_d)
-		BN_CASE_32_BIT(17, a_d)
-		BN_CASE_32_BIT(16, a_d)
-		BN_CASE_32_BIT(15, a_d)
-		BN_CASE_32_BIT(14, a_d)
-		BN_CASE_32_BIT(13, a_d)
-		BN_CASE_32_BIT(12, a_d)
-			break;
-		default: /* a->top == field->top */
-			return BN_usub(r, a, field);
+		if (!bn_wexpand(r, BN_NIST_384_TOP))
+			return 0;
+		r_d = r->d;
+		nist_cp_bn(r_d, a_d, BN_NIST_384_TOP);
 		}
+	else
+		r_d = a_d;
+
+	nist_cp_bn_0(buf, a_d + BN_NIST_384_TOP, top - BN_NIST_384_TOP, BN_NIST_384_TOP);
 
 	/*S1*/
-	BN_256_SET(t_d,0,0,0,0,0,23,22,21)
+	nist_set_256(t_d, buf, 0, 0, 0, 0, 0, 23-4, 22-4, 21-4);
 		/* left shift */
 		{
 		register BN_ULONG *ap,t,c;
 		ap = t_d;
 		c=0;
-		for (tmp_int=BN_NIST_256_TOP; tmp_int != 0; --tmp_int)
+		for (i = 3; i != 0; --i)
 			{
 			t= *ap;
 			*(ap++)=((t<<1)|c)&BN_MASK2;
 			c=(t & BN_TBIT)?1:0;
 			}
+		*ap=c;
 		}
-	if (bn_add_words(r_d+(128/BN_BITS2), r_d+(128/BN_BITS2), 
-		t_d, BN_NIST_256_TOP))
-		++carry;
-	/*S2*/
-	BN_384_SET(t_d,23,22,21,20,19,18,17,16,15,14,13,12)
-	if (bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP))
-		++carry;
+	carry = bn_add_words(r_d+(128/BN_BITS2), r_d+(128/BN_BITS2), 
+		t_d, BN_NIST_256_TOP);
+	/*S2 */
+	carry += bn_add_words(r_d, r_d, buf, BN_NIST_384_TOP);
 	/*S3*/
-	BN_384_SET(t_d,20,19,18,17,16,15,14,13,12,23,22,21)
-	if (bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP))
-		++carry;
+	nist_set_384(t_d,buf,20,19,18,17,16,15,14,13,12,23,22,21);
+	carry += bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
 	/*S4*/
-	BN_384_SET(t_d,19,18,17,16,15,14,13,12,20,0,23,0)
-	if (bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP))
-		++carry;
+	nist_set_384(t_d,buf,19,18,17,16,15,14,13,12,20,0,23,0);
+	carry += bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
 	/*S5*/
-	BN_256_SET(t_d,0,0,0,0,23,22,21,20)
-	if (bn_add_words(r_d+(128/BN_BITS2), r_d+(128/BN_BITS2), 
-		t_d, BN_NIST_256_TOP))
-		++carry;
+	nist_set_384(t_d, buf,0,0,0,0,23,22,21,20,0,0,0,0);
+	carry += bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
 	/*S6*/
-	BN_384_SET(t_d,0,0,0,0,0,0,23,22,21,0,0,20)
-	if (bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP))
-		++carry;
+	nist_set_384(t_d,buf,0,0,0,0,0,0,23,22,21,0,0,20);
+	carry += bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
 	/*D1*/
-	BN_384_SET(t_d,22,21,20,19,18,17,16,15,14,13,12,23)
-	if (bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP))
-		--carry;
+	nist_set_384(t_d,buf,22,21,20,19,18,17,16,15,14,13,12,23);
+	carry -= bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
 	/*D2*/
-	BN_384_SET(t_d,0,0,0,0,0,0,0,23,22,21,20,0)
-	if (bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP))
-		--carry;
+	nist_set_384(t_d,buf,0,0,0,0,0,0,0,23,22,21,20,0);
+	carry -= bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
 	/*D3*/
-	BN_384_SET(t_d,0,0,0,0,0,0,0,23,23,0,0,0)
-	if (bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP))
-		--carry;
-	
-	if (carry)
+	nist_set_384(t_d,buf,0,0,0,0,0,0,0,23,23,0,0,0);
+	carry -= bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
+
+	/* see BN_nist_mod_224 for explanation */
+	u.f = bn_sub_words;
+	if (carry > 0)
+		carry = bn_sub_words(r_d,r_d,_nist_p_384[carry-1],BN_NIST_384_TOP);
+	else if (carry < 0)
 		{
-		if (carry > 0)
-			bn_sub_words(r_d, r_d, _384_data + BN_NIST_384_TOP *
-				--carry, BN_NIST_384_TOP);
-		else
-			{
-			carry = -carry;
-			bn_add_words(r_d, r_d, _384_data + BN_NIST_384_TOP *
-				--carry, BN_NIST_384_TOP);
-			}
+		carry = bn_add_words(r_d,r_d,_nist_p_384[-carry-1],BN_NIST_384_TOP);
+		mask = 0-(size_t)carry;
+		u.p = ((size_t)bn_sub_words&mask) | ((size_t)bn_add_words&~mask);
 		}
+	else
+		carry = 1;
 
+	mask  = 0-(size_t)(*u.f)(c_d,r_d,_nist_p_384[0],BN_NIST_384_TOP);
+	mask &= 0-(size_t)carry;
+	res   = (BN_ULONG *)(((size_t)c_d&~mask) | ((size_t)r_d&mask));
+	nist_cp_bn(r_d, res, BN_NIST_384_TOP);
 	r->top = BN_NIST_384_TOP;
-#if 1
-	bn_clear_top2max(r);
-#endif
 	bn_correct_top(r);
 
-	if (BN_ucmp(r, field) >= 0)
+	if (BN_ucmp(field, r) <= 0)
 		{
-		bn_sub_words(r_d, r_d, _nist_p_384, BN_NIST_384_TOP);
-		bn_correct_top(r);
+		if (!BN_usub(r, r, field)) return 0;
 		}
-	bn_check_top(r);
+
 	return 1;
-#else
-	return 0;
-#endif
 	}
 
 int BN_nist_mod_521(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
@@ -800,46 +713,62 @@ int BN_nist_mod_521(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 #define BN_NIST_521_TOP_MASK	(BN_ULONG)0x1FF
 #elif BN_BITS2 == 32
 #define BN_NIST_521_TOP_MASK	(BN_ULONG)0x1FF
-#elif BN_BITS2 == 16
-#define BN_NIST_521_TOP_MASK	(BN_ULONG)0x1FF
-#elif BN_BITS2 == 8
-#define BN_NIST_521_TOP_MASK	(BN_ULONG)0x1
 #endif
 	int	top, ret = 0;
 	BN_ULONG *r_d;
 	BIGNUM	*tmp;
 
+	field = &_bignum_nist_p_521; /* just to make sure */
+
+ 	if (BN_is_negative(a))
+		return BN_nnmod(r, field, a, ctx);
+
 	/* check whether a reduction is necessary */
 	top = a->top;
 	if (top < BN_NIST_521_TOP  || ( top == BN_NIST_521_TOP &&
-           (!(a->d[BN_NIST_521_TOP-1] & ~(BN_NIST_521_TOP_MASK)))))
-		return (r == a)? 1 : (BN_copy(r ,a) != NULL);
+	    (!(a->d[BN_NIST_521_TOP-1] & ~(BN_NIST_521_TOP_MASK)))))
+		{
+		int i = BN_ucmp(field, a);
+		if (i == 0)
+			{
+			BN_zero(r);
+			return 1;
+			}
+		else
+			{
+#ifdef BN_DEBUG
+			OPENSSL_assert(i > 0); /* because 'field' is 1111...1111 */
+#endif
+			return (r == a)? 1 : (BN_copy(r ,a) != NULL);
+			}
+		}
+
+ 	if (BN_num_bits(a) > 2*521)
+		return BN_nnmod(r, field, a, ctx);
 
 	BN_CTX_start(ctx);
 	tmp = BN_CTX_get(ctx);
 	if (!tmp)
 		goto err;
 
-	if (!BN_ncopy(tmp, a, BN_NIST_521_TOP))
-		return 0;
-	if (!BN_rshift(r, a, 521))
-		return 0;
-
-	if (tmp->top == BN_NIST_521_TOP)
-		tmp->d[BN_NIST_521_TOP-1]  &= BN_NIST_521_TOP_MASK;
+	if (!bn_wexpand(tmp, BN_NIST_521_TOP))
+		goto err;
+	nist_cp_bn(tmp->d, a->d, BN_NIST_521_TOP);
 
+	tmp->top = BN_NIST_521_TOP;
+        tmp->d[BN_NIST_521_TOP-1]  &= BN_NIST_521_TOP_MASK;
 	bn_correct_top(tmp);
+
+	if (!BN_rshift(r, a, 521))
+		goto err;
+
 	if (!BN_uadd(r, tmp, r))
-		return 0;
-	top = r->top;
-	r_d = r->d;
-	if (top == BN_NIST_521_TOP  && 
-           (r_d[BN_NIST_521_TOP-1] & ~(BN_NIST_521_TOP_MASK)))
+		goto err;
+
+	if (BN_ucmp(field, r) <= 0)
 		{
-		BN_NIST_ADD_ONE(r_d)
-		r_d[BN_NIST_521_TOP-1] &= BN_NIST_521_TOP_MASK; 
+		if (!BN_usub(r, r, field)) goto err;
 		}
-	bn_correct_top(r);
 
 	ret = 1;
 err: