#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
-static const BN_ULONG _nist_p_192[] =
- {0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFEULL,
- 0xFFFFFFFFFFFFFFFFULL};
-static const BN_ULONG _nist_p_224[] =
+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_192_sqr[] = {
+ 0x0000000000000001ULL,0x0000000000000002ULL,0x0000000000000001ULL,
+ 0xFFFFFFFFFFFFFFFEULL,0xFFFFFFFFFFFFFFFDULL,0xFFFFFFFFFFFFFFFFULL
+ };
+static const BN_ULONG _nist_p_224[][BN_NIST_224_TOP] = {
{0x0000000000000001ULL,0xFFFFFFFF00000000ULL,
- 0xFFFFFFFFFFFFFFFFULL,0x00000000FFFFFFFFULL};
-static const BN_ULONG _nist_p_256[] =
+ 0xFFFFFFFFFFFFFFFFULL,0x00000000FFFFFFFFULL},
+ {0x0000000000000002ULL,0xFFFFFFFE00000000ULL,
+ 0xFFFFFFFFFFFFFFFFULL,0x00000001FFFFFFFFULL} /* this one is "carry-full" */
+ };
+static const BN_ULONG _nist_p_224_sqr[] = {
+ 0x0000000000000001ULL,0xFFFFFFFE00000000ULL,
+ 0xFFFFFFFFFFFFFFFFULL,0x0000000200000000ULL,
+ 0x0000000000000000ULL,0xFFFFFFFFFFFFFFFEULL,
+ 0xFFFFFFFFFFFFFFFFULL
+ };
+static const BN_ULONG _nist_p_256[][BN_NIST_256_TOP] = {
{0xFFFFFFFFFFFFFFFFULL,0x00000000FFFFFFFFULL,
- 0x0000000000000000ULL,0xFFFFFFFF00000001ULL};
-static const BN_ULONG _nist_p_384[] =
- {0x00000000FFFFFFFFULL,0xFFFFFFFF00000000ULL,
- 0xFFFFFFFFFFFFFFFEULL,0xFFFFFFFFFFFFFFFFULL,
- 0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL};
+ 0x0000000000000000ULL,0xFFFFFFFF00000001ULL},
+ {0xFFFFFFFFFFFFFFFEULL,0x00000001FFFFFFFFULL,
+ 0x0000000000000000ULL,0xFFFFFFFE00000002ULL},
+ {0xFFFFFFFFFFFFFFFDULL,0x00000002FFFFFFFFULL,
+ 0x0000000000000000ULL,0xFFFFFFFD00000003ULL},
+ {0xFFFFFFFFFFFFFFFCULL,0x00000003FFFFFFFFULL,
+ 0x0000000000000000ULL,0xFFFFFFFC00000004ULL},
+ {0xFFFFFFFFFFFFFFFBULL,0x00000004FFFFFFFFULL,
+ 0x0000000000000000ULL,0xFFFFFFFB00000005ULL},
+ };
+static const BN_ULONG _nist_p_256_sqr[] = {
+ 0x0000000000000001ULL,0xFFFFFFFE00000000ULL,
+ 0xFFFFFFFFFFFFFFFFULL,0x00000001FFFFFFFEULL,
+ 0x00000001FFFFFFFEULL,0x00000001FFFFFFFEULL,
+ 0xFFFFFFFE00000001ULL,0xFFFFFFFE00000002ULL
+ };
+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_384_sqr[] = {
+ 0xFFFFFFFE00000001ULL,0x0000000200000000ULL,0xFFFFFFFE00000000ULL,
+ 0x0000000200000000ULL,0x0000000000000001ULL,0x0000000000000000ULL,
+ 0x00000001FFFFFFFEULL,0xFFFFFFFE00000000ULL,0xFFFFFFFFFFFFFFFDULL,
+ 0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL
+ };
static const BN_ULONG _nist_p_521[] =
{0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
0x00000000000001FFULL};
+static const BN_ULONG _nist_p_521_sqr[] = {
+ 0x0000000000000001ULL,0x0000000000000000ULL,0x0000000000000000ULL,
+ 0x0000000000000000ULL,0x0000000000000000ULL,0x0000000000000000ULL,
+ 0x0000000000000000ULL,0x0000000000000000ULL,0xFFFFFFFFFFFFFC00ULL,
+ 0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
+ 0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
+ 0xFFFFFFFFFFFFFFFFULL,0x000000000003FFFFULL
+ };
#elif BN_BITS2 == 32
-static const BN_ULONG _nist_p_192[] = {0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFE,
- 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF};
-static const BN_ULONG _nist_p_224[] = {0x00000001,0x00000000,0x00000000,
- 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF};
-static const BN_ULONG _nist_p_256[] = {0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
- 0x00000000,0x00000000,0x00000000,0x00000001,0xFFFFFFFF};
-static const BN_ULONG _nist_p_384[] = {0xFFFFFFFF,0x00000000,0x00000000,
- 0xFFFFFFFF,0xFFFFFFFE,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
- 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_192_sqr[] = {
+ 0x00000001,0x00000000,0x00000002,0x00000000,0x00000001,0x00000000,
+ 0xFFFFFFFE,0xFFFFFFFF,0xFFFFFFFD,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_224_sqr[] = {
+ 0x00000001,0x00000000,0x00000000,0xFFFFFFFE,
+ 0xFFFFFFFF,0xFFFFFFFF,0x00000000,0x00000002,
+ 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_256_sqr[] = {
+ 0x00000001,0x00000000,0x00000000,0xFFFFFFFE,
+ 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFE,0x00000001,
+ 0xFFFFFFFE,0x00000001,0xFFFFFFFE,0x00000001,
+ 0x00000001,0xFFFFFFFE,0x00000002,0xFFFFFFFE
+ };
+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_384_sqr[] = {
+ 0x00000001,0xFFFFFFFE,0x00000000,0x00000002,0x00000000,0xFFFFFFFE,
+ 0x00000000,0x00000002,0x00000001,0x00000000,0x00000000,0x00000000,
+ 0xFFFFFFFE,0x00000001,0x00000000,0xFFFFFFFE,0xFFFFFFFD,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};
+static const BN_ULONG _nist_p_521_sqr[] = {
+ 0x00000001,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,
+ 0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,
+ 0x00000000,0x00000000,0x00000000,0x00000000,0xFFFFFC00,0xFFFFFFFF,
+ 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
+ 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
+ 0xFFFFFFFF,0xFFFFFFFF,0x0003FFFF
+ };
+#else
+#error "unsupported BN_BITS2"
#endif
static const BIGNUM _bignum_nist_p_192 =
{
- (BN_ULONG *)_nist_p_192,
+ (BN_ULONG *)_nist_p_192[0],
BN_NIST_192_TOP,
BN_NIST_192_TOP,
0,
static const BIGNUM _bignum_nist_p_224 =
{
- (BN_ULONG *)_nist_p_224,
+ (BN_ULONG *)_nist_p_224[0],
BN_NIST_224_TOP,
BN_NIST_224_TOP,
0,
static const BIGNUM _bignum_nist_p_256 =
{
- (BN_ULONG *)_nist_p_256,
+ (BN_ULONG *)_nist_p_256[0],
BN_NIST_256_TOP,
BN_NIST_256_TOP,
0,
static const BIGNUM _bignum_nist_p_384 =
{
- (BN_ULONG *)_nist_p_384,
+ (BN_ULONG *)_nist_p_384[0],
BN_NIST_384_TOP,
BN_NIST_384_TOP,
0,
int i;
BN_ULONG *_tmp1 = (buf), *_tmp2 = (a);
+#ifdef BN_DEBUG
OPENSSL_assert(top <= max);
+#endif
for (i = (top); i != 0; i--)
*_tmp1++ = *_tmp2++;
for (i = (max) - (top); i != 0; i--)
#if BN_BITS2 == 64
#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;
-/* TBD */
-#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;
+/*
+ * 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 bn_cp_64(to, n, from, m) \
{ \
#define nist_set_192(to, from, a1, a2, a3) \
{ \
- if (a3 != 0) bn_cp_64(to, 0, from, (a3) - 3) else bn_64_set_0(to, 0)\
+ bn_cp_64(to, 0, from, (a3) - 3) \
bn_cp_64(to, 1, from, (a2) - 3) \
- if (a1 != 0) bn_cp_64(to, 2, from, (a1) - 3) else bn_64_set_0(to, 2)\
+ bn_cp_64(to, 2, from, (a1) - 3) \
}
int BN_nist_mod_192(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
c_d[BN_NIST_192_TOP],
*res;
size_t mask;
+ static const BIGNUM _bignum_nist_p_192_sqr = {
+ (BN_ULONG *)_nist_p_192_sqr,
+ sizeof(_nist_p_192_sqr)/sizeof(_nist_p_192_sqr[0]),
+ sizeof(_nist_p_192_sqr)/sizeof(_nist_p_192_sqr[0]),
+ 0,BN_FLG_STATIC_DATA };
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);
+ if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_192_sqr)>=0)
+ return BN_nnmod(r, a, field, ctx);
i = BN_ucmp(field, a);
if (i == 0)
nist_cp_bn_0(buf, a_d + BN_NIST_192_TOP, top - BN_NIST_192_TOP, BN_NIST_192_TOP);
nist_set_192(t_d, buf, 0, 3, 3);
- carry = bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP);
- mask = 0-(size_t)bn_sub_words(c_d,r_d,_nist_p_192,BN_NIST_192_TOP);
- mask = ~mask | (0-(size_t)carry);
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)r_d&~mask));
-
+ carry = (int)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, res, t_d, BN_NIST_192_TOP);
- mask = 0-(size_t)bn_sub_words(c_d,r_d,_nist_p_192,BN_NIST_192_TOP);
- mask = ~mask | (0-(size_t)carry);
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)r_d&~mask));
-
+ carry += (int)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, res, t_d, BN_NIST_192_TOP);
- mask = 0-(size_t)bn_sub_words(c_d,r_d,_nist_p_192,BN_NIST_192_TOP);
- mask = ~mask | (0-(size_t)carry);
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)r_d&~mask));
+ carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP);
+ if (carry > 0)
+ carry = (int)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;
bn_correct_top(r);
- if (BN_ucmp(field, r) <= 0)
- {
- if (!BN_usub(r, r, field)) return 0;
- }
-
return 1;
}
+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) \
{ \
- if (a7 != 0) bn_cp_32(to, 0, from, (a7) - 7) else bn_32_set_0(to, 0)\
- if (a6 != 0) bn_cp_32(to, 1, from, (a6) - 7) else bn_32_set_0(to, 1)\
- if (a5 != 0) bn_cp_32(to, 2, from, (a5) - 7) else bn_32_set_0(to, 2)\
- if (a4 != 0) bn_cp_32(to, 3, from, (a4) - 7) else bn_32_set_0(to, 3)\
- if (a3 != 0) bn_cp_32(to, 4, from, (a3) - 7) else bn_32_set_0(to, 4)\
- if (a2 != 0) bn_cp_32(to, 5, from, (a2) - 7) else bn_32_set_0(to, 5)\
- if (a1 != 0) bn_cp_32(to, 6, from, (a1) - 7) else bn_32_set_0(to, 6)\
+ 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)
{
-#if BN_BITS2 == 32
int top = a->top, i;
int carry;
BN_ULONG *r_d, *a_d = a->d;
c_d[BN_NIST_224_TOP],
*res;
size_t mask;
+ union { bn_addsub_f f; size_t p; } u;
+ static const BIGNUM _bignum_nist_p_224_sqr = {
+ (BN_ULONG *)_nist_p_224_sqr,
+ sizeof(_nist_p_224_sqr)/sizeof(_nist_p_224_sqr[0]),
+ sizeof(_nist_p_224_sqr)/sizeof(_nist_p_224_sqr[0]),
+ 0,BN_FLG_STATIC_DATA };
+
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);
+ if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_224_sqr)>=0)
+ return BN_nnmod(r, a, field, ctx);
i = BN_ucmp(field, a);
if (i == 0)
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);
- mask = 0-(size_t)bn_sub_words(c_d,r_d,_nist_p_224,BN_NIST_224_TOP);
- mask = ~mask | (0-(size_t)carry);
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)r_d&~mask));
-
+ carry = (int)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, res, t_d, BN_NIST_224_TOP);
- mask = 0-(size_t)bn_sub_words(c_d,r_d,_nist_p_224,BN_NIST_224_TOP);
- mask = ~mask | (0-(size_t)carry);
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)r_d&~mask));
-
+ carry += (int)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);
-#if BRANCH_FREE
- carry = bn_sub_words(r_d, res, t_d, BN_NIST_224_TOP);
- bn_add_words(c_d,r_d,_nist_p_224,BN_NIST_224_TOP);
- mask = 0-(size_t)carry;
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)r_d&~mask));
-#else
- if (bn_sub_words(r_d, res, t_d, BN_NIST_224_TOP))
- bn_add_words(r_d,r_d,_nist_p_224,BN_NIST_224_TOP);
-#endif
+ carry -= (int)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);
-#if BRANCH_FREE
- carry = bn_sub_words(r_d, res, t_d, BN_NIST_224_TOP);
- bn_add_words(c_d,r_d,_nist_p_224,BN_NIST_224_TOP);
- mask = 0-(size_t)carry;
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)r_d&~mask));
+ carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP);
- nist_cp_bn(r_d, res, BN_NIST_224_TOP);
-#else
- if (bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP))
- bn_add_words(r_d,r_d,_nist_p_224,BN_NIST_224_TOP);
+#if BN_BITS2==64
+ carry = (int)(r_d[BN_NIST_224_TOP-1]>>32);
#endif
- r->top = BN_NIST_224_TOP;
- bn_correct_top(r);
-
- if (BN_ucmp(field, r) <= 0)
+ u.f = bn_sub_words;
+ if (carry > 0)
{
- if (!BN_usub(r, r, field)) return 0;
+ carry = (int)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)
+ {
+ /* 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 = (int)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;
+ bn_correct_top(r);
return 1;
-#else /* BN_BITS!=32 */
- return 0;
-#endif
}
#define nist_set_256(to, from, a1, a2, a3, a4, a5, a6, a7, a8) \
{ \
- if (a8 != 0) bn_cp_32(to, 0, from, (a8) - 8) else bn_32_set_0(to, 0)\
- if (a7 != 0) bn_cp_32(to, 1, from, (a7) - 8) else bn_32_set_0(to, 1)\
- if (a6 != 0) bn_cp_32(to, 2, from, (a6) - 8) else bn_32_set_0(to, 2)\
- if (a5 != 0) bn_cp_32(to, 3, from, (a5) - 8) else bn_32_set_0(to, 3)\
- if (a4 != 0) bn_cp_32(to, 4, from, (a4) - 8) else bn_32_set_0(to, 4)\
- if (a3 != 0) bn_cp_32(to, 5, from, (a3) - 8) else bn_32_set_0(to, 5)\
- if (a2 != 0) bn_cp_32(to, 6, from, (a2) - 8) else bn_32_set_0(to, 6)\
- if (a1 != 0) bn_cp_32(to, 7, from, (a1) - 8) else bn_32_set_0(to, 7)\
+ 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)
{
-#if BN_BITS2 == 32
int i, top = a->top;
int carry = 0;
register BN_ULONG *a_d = a->d, *r_d;
c_d[BN_NIST_256_TOP],
*res;
size_t mask;
+ union { bn_addsub_f f; size_t p; } u;
+ static const BIGNUM _bignum_nist_p_256_sqr = {
+ (BN_ULONG *)_nist_p_256_sqr,
+ sizeof(_nist_p_256_sqr)/sizeof(_nist_p_256_sqr[0]),
+ sizeof(_nist_p_256_sqr)/sizeof(_nist_p_256_sqr[0]),
+ 0,BN_FLG_STATIC_DATA };
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);
+ if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_256_sqr)>=0)
+ return BN_nnmod(r, a, field, ctx);
i = BN_ucmp(field, a);
if (i == 0)
/*S1*/
nist_set_256(t_d, buf, 15, 14, 13, 12, 11, 0, 0, 0);
/*S2*/
- 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);
- mask = 0-(size_t)bn_sub_words(c_d,t_d,_nist_p_256,BN_NIST_256_TOP);
- mask = ~mask | (0-(size_t)carry);
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)t_d&~mask));
-
- carry = bn_add_words(t_d, res, res, BN_NIST_256_TOP);
- mask = 0-(size_t)bn_sub_words(c_d,t_d,_nist_p_256,BN_NIST_256_TOP);
- mask = ~mask | (0-(size_t)carry);
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)t_d&~mask));
-
- carry = bn_add_words(r_d, r_d, res, BN_NIST_256_TOP);
- mask = 0-(size_t)bn_sub_words(c_d,r_d,_nist_p_256,BN_NIST_256_TOP);
- mask = ~mask | (0-(size_t)carry);
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)r_d&~mask));
-
+ nist_set_256(c_d, buf, 0, 15, 14, 13, 12, 0, 0, 0);
+ carry = (int)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 (i = BN_NIST_256_TOP; i != 0; --i)
+ {
+ t= *ap;
+ *(ap++)=((t<<1)|c)&BN_MASK2;
+ c=(t & BN_TBIT)?1:0;
+ }
+ carry <<= 1;
+ carry |= c;
+ }
+ carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);
/*S3*/
nist_set_256(t_d, buf, 15, 14, 0, 0, 0, 10, 9, 8);
- carry = bn_add_words(r_d, res, t_d, BN_NIST_256_TOP);
- mask = 0-(size_t)bn_sub_words(c_d,r_d,_nist_p_256,BN_NIST_256_TOP);
- mask = ~mask | (0-(size_t)carry);
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)r_d&~mask));
-
+ carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);
/*S4*/
nist_set_256(t_d, buf, 8, 13, 15, 14, 13, 11, 10, 9);
- carry = bn_add_words(r_d, res, t_d, BN_NIST_256_TOP);
- mask = 0-(size_t)bn_sub_words(c_d,r_d,_nist_p_256,BN_NIST_256_TOP);
- mask = ~mask | (0-(size_t)carry);
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)r_d&~mask));
-
+ carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);
/*D1*/
nist_set_256(t_d, buf, 10, 8, 0, 0, 0, 13, 12, 11);
-#if BRANCH_FREE
- carry = bn_sub_words(r_d, res, t_d, BN_NIST_256_TOP);
- bn_add_words(c_d,r_d,_nist_p_256,BN_NIST_256_TOP);
- mask = 0-(size_t)carry;
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)r_d&~mask));
-#else
- if (bn_sub_words(r_d, res, t_d, BN_NIST_256_TOP))
- bn_add_words(r_d,r_d,_nist_p_256,BN_NIST_256_TOP);
-#endif
+ carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
/*D2*/
nist_set_256(t_d, buf, 11, 9, 0, 0, 15, 14, 13, 12);
-#if BRANCH_FREE
- carry = bn_sub_words(r_d, res, t_d, BN_NIST_256_TOP);
- bn_add_words(c_d,r_d,_nist_p_256,BN_NIST_256_TOP);
- mask = 0-(size_t)carry;
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)r_d&~mask));
-#else
- if (bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP))
- bn_add_words(r_d,r_d,_nist_p_256,BN_NIST_256_TOP);
-#endif
+ carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
/*D3*/
nist_set_256(t_d, buf, 12, 0, 10, 9, 8, 15, 14, 13);
-#if BRANCH_FREE
- carry = bn_sub_words(r_d, res, t_d, BN_NIST_256_TOP);
- bn_add_words(c_d,r_d,_nist_p_256,BN_NIST_256_TOP);
- mask = 0-(size_t)carry;
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)r_d&~mask));
-#else
- if (bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP))
- bn_add_words(r_d,r_d,_nist_p_256,BN_NIST_256_TOP);
-#endif
+ carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
/*D4*/
nist_set_256(t_d, buf, 13, 0, 11, 10, 9, 0, 15, 14);
-#if BRANCH_FREE
- carry = bn_sub_words(r_d, res, t_d, BN_NIST_256_TOP);
- bn_add_words(c_d,r_d,_nist_p_256,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_384_TOP);
-#else
- if (bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP))
- bn_add_words(r_d,r_d,_nist_p_256,BN_NIST_256_TOP);
-#endif
- r->top = BN_NIST_256_TOP;
- bn_correct_top(r);
+ carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
- if (BN_ucmp(field, r) <= 0)
+ /* see BN_nist_mod_224 for explanation */
+ u.f = bn_sub_words;
+ if (carry > 0)
+ carry = (int)bn_sub_words(r_d,r_d,_nist_p_256[carry-1],BN_NIST_256_TOP);
+ else if (carry < 0)
{
- if (!BN_usub(r, r, field)) return 0;
+ carry = (int)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;
+ bn_correct_top(r);
return 1;
-#else /* BN_BITS!=32 */
- return 0;
-#endif
}
#define nist_set_384(to,from,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12) \
{ \
- if (a12 != 0) bn_cp_32(to, 0, from, (a12) - 12) else bn_32_set_0(to, 0)\
- if (a11 != 0) bn_cp_32(to, 1, from, (a11) - 12) else bn_32_set_0(to, 1)\
- if (a10 != 0) bn_cp_32(to, 2, from, (a10) - 12) else bn_32_set_0(to, 2)\
- if (a9 != 0) bn_cp_32(to, 3, from, (a9) - 12) else bn_32_set_0(to, 3)\
- if (a8 != 0) bn_cp_32(to, 4, from, (a8) - 12) else bn_32_set_0(to, 4)\
- if (a7 != 0) bn_cp_32(to, 5, from, (a7) - 12) else bn_32_set_0(to, 5)\
- if (a6 != 0) bn_cp_32(to, 6, from, (a6) - 12) else bn_32_set_0(to, 6)\
- if (a5 != 0) bn_cp_32(to, 7, from, (a5) - 12) else bn_32_set_0(to, 7)\
- if (a4 != 0) bn_cp_32(to, 8, from, (a4) - 12) else bn_32_set_0(to, 8)\
- if (a3 != 0) bn_cp_32(to, 9, from, (a3) - 12) else bn_32_set_0(to, 9)\
- if (a2 != 0) bn_cp_32(to, 10, from, (a2) - 12) else bn_32_set_0(to, 10)\
- if (a1 != 0) bn_cp_32(to, 11, from, (a1) - 12) else bn_32_set_0(to, 11)\
+ 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)
{
-#if BN_BITS2 == 32
int i, top = a->top;
int carry = 0;
register BN_ULONG *r_d, *a_d = a->d;
c_d[BN_NIST_384_TOP],
*res;
size_t mask;
+ union { bn_addsub_f f; size_t p; } u;
+ static const BIGNUM _bignum_nist_p_384_sqr = {
+ (BN_ULONG *)_nist_p_384_sqr,
+ sizeof(_nist_p_384_sqr)/sizeof(_nist_p_384_sqr[0]),
+ sizeof(_nist_p_384_sqr)/sizeof(_nist_p_384_sqr[0]),
+ 0,BN_FLG_STATIC_DATA };
+
field = &_bignum_nist_p_384; /* just to make sure */
- if (BN_is_negative(a) || a->top > 2*BN_NIST_384_TOP)
- return BN_nnmod(r, field, a, ctx);
+ if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_384_sqr)>=0)
+ return BN_nnmod(r, a, field, ctx);
i = BN_ucmp(field, a);
if (i == 0)
}
*ap=c;
}
- carry = bn_add_words(r_d+(128/BN_BITS2), r_d+(128/BN_BITS2),
+ carry = (int)bn_add_words(r_d+(128/BN_BITS2), r_d+(128/BN_BITS2),
t_d, BN_NIST_256_TOP);
- /*
- * we need if (result>=modulus) subtract(result,modulus);
- * in n-bit space this can be expressed as
- * if (carry || result>=modulus) subtract(result,modulus);
- * the catch is that comparison implies subtraction and
- * therefore one can write tmp=subtract(result,modulus);
- * and then if(carry || !borrow) result=tmp; this's what
- * happens below, but without explicit if:-) a.
- */
- mask = 0-(size_t)bn_sub_words(c_d,r_d,_nist_p_384,BN_NIST_384_TOP);
- mask = ~mask | (0-(size_t)carry);
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)r_d&~mask));
-
/*S2 */
- carry = bn_add_words(r_d, res, buf, BN_NIST_384_TOP);
- mask = 0-(size_t)bn_sub_words(c_d,r_d,_nist_p_384,BN_NIST_384_TOP);
- mask = ~mask | (0-(size_t)carry);
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)r_d&~mask));
-
+ carry += (int)bn_add_words(r_d, r_d, buf, BN_NIST_384_TOP);
/*S3*/
nist_set_384(t_d,buf,20,19,18,17,16,15,14,13,12,23,22,21);
- carry = bn_add_words(r_d, res, t_d, BN_NIST_384_TOP);
- mask = 0-(size_t)bn_sub_words(c_d,r_d,_nist_p_384,BN_NIST_384_TOP);
- mask = ~mask | (0-(size_t)carry);
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)r_d&~mask));
-
+ carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
/*S4*/
nist_set_384(t_d,buf,19,18,17,16,15,14,13,12,20,0,23,0);
- carry = bn_add_words(r_d, res, t_d, BN_NIST_384_TOP);
- mask = 0-(size_t)bn_sub_words(c_d,r_d,_nist_p_384,BN_NIST_384_TOP);
- mask = ~mask | (0-(size_t)carry);
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)r_d&~mask));
-
+ carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
/*S5*/
nist_set_384(t_d, buf,0,0,0,0,23,22,21,20,0,0,0,0);
- carry = bn_add_words(r_d, res, t_d, BN_NIST_384_TOP);
- mask = 0-(size_t)bn_sub_words(c_d,r_d,_nist_p_384,BN_NIST_384_TOP);
- mask = ~mask | (0-(size_t)carry);
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)r_d&~mask));
-
+ carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
/*S6*/
nist_set_384(t_d,buf,0,0,0,0,0,0,23,22,21,0,0,20);
- carry = bn_add_words(r_d, res, t_d, BN_NIST_384_TOP);
- mask = 0-(size_t)bn_sub_words(c_d,r_d,_nist_p_384,BN_NIST_384_TOP);
- mask = ~mask | (0-(size_t)carry);
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)r_d&~mask));
-
+ carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
/*D1*/
nist_set_384(t_d,buf,22,21,20,19,18,17,16,15,14,13,12,23);
-#if BRANCH_FREE
- carry = bn_sub_words(r_d, res, t_d, BN_NIST_384_TOP);
- bn_add_words(c_d,r_d,_nist_p_384,BN_NIST_384_TOP);
- mask = 0-(size_t)carry;
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)r_d&~mask));
-#else
- if (bn_sub_words(r_d, res, t_d, BN_NIST_384_TOP))
- bn_add_words(r_d,r_d,_nist_p_384,BN_NIST_384_TOP);
-#endif
+ carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
/*D2*/
nist_set_384(t_d,buf,0,0,0,0,0,0,0,23,22,21,20,0);
-#if BRANCH_FREE
- carry = bn_sub_words(r_d, res, t_d, BN_NIST_384_TOP);
- bn_add_words(c_d,r_d,_nist_p_384,BN_NIST_384_TOP);
- mask = 0-(size_t)carry;
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)r_d&~mask));
-#else
- if (bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP))
- bn_add_words(r_d,r_d,_nist_p_384,BN_NIST_384_TOP);
-#endif
+ carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
/*D3*/
nist_set_384(t_d,buf,0,0,0,0,0,0,0,23,23,0,0,0);
-#if BRANCH_FREE
- carry = bn_sub_words(r_d, res, t_d, BN_NIST_384_TOP);
- bn_add_words(c_d,r_d,_nist_p_384,BN_NIST_384_TOP);
- mask = 0-(size_t)carry;
- res = (BN_ULONG *)(((size_t)c_d&mask) | ((size_t)r_d&~mask));
+ carry -= (int)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 = (int)bn_sub_words(r_d,r_d,_nist_p_384[carry-1],BN_NIST_384_TOP);
+ else if (carry < 0)
+ {
+ carry = (int)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);
-#else
- if (bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP))
- bn_add_words(r_d,r_d,_nist_p_384,BN_NIST_384_TOP);
-#endif
r->top = BN_NIST_384_TOP;
bn_correct_top(r);
- if (BN_ucmp(field, r) <= 0)
- {
- if (!BN_usub(r, r, field)) return 0;
- }
-
return 1;
-#else /* BN_BITS!=32 */
- return 0;
-#endif
}
+#define BN_NIST_521_RSHIFT (521%BN_BITS2)
+#define BN_NIST_521_LSHIFT (BN_BITS2-BN_NIST_521_RSHIFT)
+#define BN_NIST_521_TOP_MASK ((BN_ULONG)BN_MASK2>>BN_NIST_521_LSHIFT)
+
int BN_nist_mod_521(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
BN_CTX *ctx)
{
-#if BN_BITS2 == 64
-#define BN_NIST_521_TOP_MASK (BN_ULONG)0x1FF
-#elif BN_BITS2 == 32
-#define BN_NIST_521_TOP_MASK (BN_ULONG)0x1FF
-#endif
- int top, ret = 0;
- BIGNUM *tmp;
+ int top = a->top, i;
+ BN_ULONG *r_d, *a_d = a->d,
+ t_d[BN_NIST_521_TOP],
+ val,tmp,*res;
+ size_t mask;
+ static const BIGNUM _bignum_nist_p_521_sqr = {
+ (BN_ULONG *)_nist_p_521_sqr,
+ sizeof(_nist_p_521_sqr)/sizeof(_nist_p_521_sqr[0]),
+ sizeof(_nist_p_521_sqr)/sizeof(_nist_p_521_sqr[0]),
+ 0,BN_FLG_STATIC_DATA };
field = &_bignum_nist_p_521; /* just to make sure */
- if (BN_is_negative(a))
- return BN_nnmod(r, field, a, ctx);
+ if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_521_sqr)>=0)
+ return BN_nnmod(r, a, field, 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)))))
+ i = BN_ucmp(field, a);
+ if (i == 0)
{
- 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);
- }
+ BN_zero(r);
+ return 1;
}
+ else if (i > 0)
+ 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_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))
- goto err;
-
- if (BN_ucmp(field, r) <= 0)
+ if (r != a)
{
- if (!BN_usub(r, r, field)) goto err;
+ if (!bn_wexpand(r,BN_NIST_521_TOP))
+ return 0;
+ r_d = r->d;
+ nist_cp_bn(r_d,a_d, BN_NIST_521_TOP);
}
+ else
+ r_d = a_d;
- ret = 1;
-err:
- BN_CTX_end(ctx);
+ /* upper 521 bits, copy ... */
+ nist_cp_bn_0(t_d,a_d + (BN_NIST_521_TOP-1), top - (BN_NIST_521_TOP-1),BN_NIST_521_TOP);
+ /* ... and right shift */
+ for (val=t_d[0],i=0; i<BN_NIST_521_TOP-1; i++)
+ {
+ tmp = val>>BN_NIST_521_RSHIFT;
+ val = t_d[i+1];
+ t_d[i] = (tmp | val<<BN_NIST_521_LSHIFT) & BN_MASK2;
+ }
+ t_d[i] = val>>BN_NIST_521_RSHIFT;
+ /* lower 521 bits */
+ r_d[i] &= BN_NIST_521_TOP_MASK;
+
+ bn_add_words(r_d,r_d,t_d,BN_NIST_521_TOP);
+ mask = 0-(size_t)bn_sub_words(t_d,r_d,_nist_p_521,BN_NIST_521_TOP);
+ res = (BN_ULONG *)(((size_t)t_d&~mask) | ((size_t)r_d&mask));
+ nist_cp_bn(r_d,res,BN_NIST_521_TOP);
+ r->top = BN_NIST_521_TOP;
+ bn_correct_top(r);
- bn_check_top(r);
- return ret;
+ return 1;
}
projects / oweals / openssl.git / commitdiff