Fix remaining BN_nist_mod_*.

PR: 1593

diff --git a/crypto/bn/bn_nist.c b/crypto/bn/bn_nist.c
index 0eabb0332baa0f49d713a61916f0bc70248f6a94..5766c44d751e0b49b08969a988f742176bf2f697 100644 (file)
--- a/crypto/bn/bn_nist.c
+++ b/crypto/bn/bn_nist.c
@@ -171,13 +171,6 @@ const BIGNUM *BN_get0_nist_prime_521(void)
        return &const_nist_521;
        }
 
-/* some misc internal functions */
-#if BN_BITS2 != 64
-static BN_ULONG _256_data[BN_NIST_256_TOP*6];
-static int _is_set_256_data = 0;
-static void _init_256_data(void);
-#endif
-
 #define BN_NIST_ADD_ONE(a)     while (!(*(a)=(*(a)+1)&BN_MASK2)) ++(a);
 
 static void nist_cp_bn_0(BN_ULONG *buf, BN_ULONG *a, int top, int max)
@@ -251,9 +244,13 @@ int BN_nist_mod_192(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
        BN_CTX *ctx)
        {
        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];
+                buf[BN_NIST_192_TOP],
+                c_d[BN_NIST_192_TOP],
+               *res;
+       size_t   mask;
 
        i = BN_ucmp(field, a);
        if (i == 0)
@@ -285,30 +282,31 @@ int BN_nist_mod_192(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 #endif
 
        nist_set_192(t_d, buf, 0, 3, 3);
-       if (bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP))
-               bn_sub_words(r_d, r_d, _nist_p_192, BN_NIST_192_TOP);
-
+       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));
+       
        nist_set_192(t_d, buf, 4, 4, 0);
-       if (bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP))
-               bn_sub_words(r_d, r_d, _nist_p_192, BN_NIST_192_TOP);
+       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));
 
 #if defined(OPENSSL_SYS_VMS) && defined(__DECC)
 # pragma message restore
 #endif
 
        nist_set_192(t_d, buf, 5, 5, 5)
-       if (bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP))
-               bn_sub_words(r_d, r_d, _nist_p_192, BN_NIST_192_TOP);
+       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));
 
+       nist_cp_bn(r_d, res, BN_NIST_192_TOP);
        r->top = BN_NIST_192_TOP;
        bn_correct_top(r);
-       if (BN_ucmp(r, field) >= 0)
-               {
-               bn_sub_words(r_d, r_d, _nist_p_192, BN_NIST_192_TOP);
-               bn_correct_top(r);
-               }
 
-       bn_check_top(r);
        return 1;
        }
 
@@ -328,9 +326,13 @@ int BN_nist_mod_224(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
        {
 #if BN_BITS2 == 32
        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];
+                buf[BN_NIST_224_TOP],
+                c_d[BN_NIST_224_TOP],
+               *res;
+       size_t   mask;
 
        i = BN_ucmp(field, a);
        if (i == 0)
@@ -357,52 +359,48 @@ int BN_nist_mod_224(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
        nist_cp_bn_0(buf, a_d + BN_NIST_224_TOP, top - BN_NIST_224_TOP, BN_NIST_224_TOP);
 
        nist_set_224(t_d, buf, 10, 9, 8, 7, 0, 0, 0);
-       if (bn_add_words(r_d, r_d, t_d, BN_NIST_224_TOP))
-               bn_sub_words(r_d,r_d,_nist_p_224,BN_NIST_224_TOP);
+       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));
+       
        nist_set_224(t_d, buf, 0, 13, 12, 11, 0, 0, 0);
-       if (bn_add_words(r_d, r_d, t_d, BN_NIST_224_TOP))
-               bn_sub_words(r_d,r_d,_nist_p_224,BN_NIST_224_TOP);
+       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));
+
        nist_set_224(t_d, buf, 13, 12, 11, 10, 9, 8, 7);
-       if (bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP))
+#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
        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));
+
+       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);
-
+#endif
        r->top = BN_NIST_224_TOP;
        bn_correct_top(r);
-       if (BN_ucmp(r, field) >= 0)
-               {
-               bn_sub_words(r_d, r_d, _nist_p_224, BN_NIST_224_TOP);
-               bn_correct_top(r);
-               }
-       bn_check_top(r);
+
        return 1;
-#else
+#else  /* BN_BITS!=32 */
        return 0;
 #endif
        }
 
-#if BN_BITS2 == 32
-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;
-       }
-#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)\
@@ -423,19 +421,11 @@ int BN_nist_mod_256(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
        int     carry = 0;
        register BN_ULONG *a_d = a->d, *r_d;
        BN_ULONG t_d[BN_NIST_256_TOP],
-                t_d2[BN_NIST_256_TOP],
-                buf[BN_NIST_256_TOP];
+                buf[BN_NIST_256_TOP],
+                c_d[BN_NIST_256_TOP],
+               *res;
+       size_t   mask;
 
-       if (!_is_set_256_data)
-               {
-               CRYPTO_w_lock(CRYPTO_LOCK_BN);
-               
-               if (!_is_set_256_data)
-                       _init_256_data();
-               
-               CRYPTO_w_unlock(CRYPTO_LOCK_BN);
-               }
-       
        i = BN_ucmp(field, a);
        if (i == 0)
                {
@@ -463,62 +453,87 @@ int BN_nist_mod_256(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
        /*S1*/
        nist_set_256(t_d, buf, 15, 14, 13, 12, 11, 0, 0, 0);
        /*S2*/
-       nist_set_256(t_d2,buf, 0, 15, 14, 13, 12, 0, 0, 0);
-       carry = bn_add_words(t_d, t_d, t_d2, 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;
-               }
+       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));
 
-       carry += 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, r_d, t_d, BN_NIST_256_TOP);
+       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));
+
        /*S4*/
        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);
-
-       if (carry)
-               bn_sub_words(r_d, r_d, _256_data + BN_NIST_256_TOP *
-                               (carry-1), BN_NIST_256_TOP);
+       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));
 
        /*D1*/
        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);
+#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
        /*D2*/
        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);
+#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
        /*D3*/
        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);
+#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
        /*D4*/
        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);
-       
-       if (carry)
-               bn_add_words(r_d, r_d, _256_data + BN_NIST_256_TOP *
-                               (carry-1), BN_NIST_256_TOP);
+#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);
-       if (BN_ucmp(r, field) >= 0)
-               {
-               bn_sub_words(r_d, r_d, _nist_p_256, BN_NIST_256_TOP);
-               bn_correct_top(r);
-               }
-       bn_check_top(r);
+
        return 1;
-#else
+#else  /* BN_BITS!=32 */
        return 0;
 #endif
        }
@@ -679,7 +694,7 @@ int BN_nist_mod_384(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
        bn_correct_top(r);
 
        return 1;
-#else
+#else  /* BN_BITS!=32 */
        return 0;
 #endif
        }