bn_nist.c: harmonize buf in BN_nist_mod_256 with other mod functions and

compensate for VC buf [from HEAD].

PR: 2837

diff --git a/crypto/bn/bn_nist.c b/crypto/bn/bn_nist.c
index 43caee477031e1316571b51aa9d39b96ff02857d..0797f929184f0a7e02b02d973e991b2787609edb 100644 (file)
--- a/crypto/bn/bn_nist.c
+++ b/crypto/bn/bn_nist.c
@@ -286,10 +286,11 @@ const BIGNUM *BN_get0_nist_prime_521(void)
        }
 
 
-static void nist_cp_bn_0(BN_ULONG *buf, BN_ULONG *a, int top, int max)
+static void nist_cp_bn_0(BN_ULONG *buf, const BN_ULONG *a, int top, int max)
        {
        int i;
-       BN_ULONG *_tmp1 = (buf), *_tmp2 = (a);
+       BN_ULONG *_tmp1 = (buf);
+       const BN_ULONG *_tmp2 = (a);
 
 #ifdef BN_DEBUG
        OPENSSL_assert(top <= max);
@@ -300,10 +301,12 @@ static void nist_cp_bn_0(BN_ULONG *buf, BN_ULONG *a, int top, int max)
                *_tmp1++ = (BN_ULONG) 0;
        }
 
-static void nist_cp_bn(BN_ULONG *buf, BN_ULONG *a, int top)
+static void nist_cp_bn(BN_ULONG *buf, const BN_ULONG *a, int top)
        { 
        int i;
-       BN_ULONG *_tmp1 = (buf), *_tmp2 = (a);
+       BN_ULONG *_tmp1 = (buf);
+       const BN_ULONG *_tmp2 = (a);
+
        for (i = (top); i != 0; i--)
                *_tmp1++ = *_tmp2++;
        }
@@ -451,8 +454,9 @@ int BN_nist_mod_192(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
         */
        mask  = 0-(PTR_SIZE_INT)bn_sub_words(c_d,r_d,_nist_p_192[0],BN_NIST_192_TOP);
        mask &= 0-(PTR_SIZE_INT)carry;
+       res   = c_d;
        res   = (BN_ULONG *)
-        (((PTR_SIZE_INT)c_d&~mask) | ((PTR_SIZE_INT)r_d&mask));
+        (((PTR_SIZE_INT)res&~mask) | ((PTR_SIZE_INT)r_d&mask));
        nist_cp_bn(r_d, res, BN_NIST_192_TOP);
        r->top = BN_NIST_192_TOP;
        bn_correct_top(r);
@@ -479,8 +483,11 @@ int BN_nist_mod_224(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
        int     top = a->top, i;
        int     carry;
        BN_ULONG *r_d, *a_d = a->d;
-       BN_ULONG buf[BN_NIST_224_TOP],
-                c_d[BN_NIST_224_TOP],
+       union   {
+               BN_ULONG        bn[BN_NIST_224_TOP];
+               unsigned int    ui[BN_NIST_224_TOP*sizeof(BN_ULONG)/sizeof(unsigned int)];
+               } buf;
+       BN_ULONG c_d[BN_NIST_224_TOP],
                *res;
        PTR_SIZE_INT mask;
        union { bn_addsub_f f; PTR_SIZE_INT p; } u;
@@ -519,18 +526,18 @@ int BN_nist_mod_224(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
        /* copy upper 256 bits of 448 bit number ... */
        nist_cp_bn_0(c_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, c_d, 14, 13, 12, 11, 10, 9, 8);
+       nist_set_224(buf.bn, c_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);
+       nist_cp_bn_0(buf.bn, a_d + BN_NIST_224_TOP, top - BN_NIST_224_TOP, BN_NIST_224_TOP);
 #endif
 
 #if defined(NIST_INT64) && BN_BITS2!=64
        {
        NIST_INT64              acc;    /* accumulator */
        unsigned int            *rp=(unsigned int *)r_d;
-       const unsigned int      *bp=(const unsigned int *)buf;
+       const unsigned int      *bp=(const unsigned int *)buf.ui;
 
        acc  = rp[0];   acc -= bp[7-7];
                        acc -= bp[11-7]; rp[0] = (unsigned int)acc; acc >>= 32;
@@ -565,13 +572,13 @@ int BN_nist_mod_224(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
        {
        BN_ULONG t_d[BN_NIST_224_TOP];
 
-       nist_set_224(t_d, buf, 10, 9, 8, 7, 0, 0, 0);
+       nist_set_224(t_d, buf.bn, 10, 9, 8, 7, 0, 0, 0);
        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);
+       nist_set_224(t_d, buf.bn, 0, 13, 12, 11, 0, 0, 0);
        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);
+       nist_set_224(t_d, buf.bn, 13, 12, 11, 10, 9, 8, 7);
        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);
+       nist_set_224(t_d, buf.bn, 0, 0, 0, 0, 13, 12, 11);
        carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP);
 
 #if BN_BITS2==64
@@ -606,7 +613,8 @@ int BN_nist_mod_224(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
        /* otherwise it's effectively same as in BN_nist_mod_192... */
        mask  = 0-(PTR_SIZE_INT)(*u.f)(c_d,r_d,_nist_p_224[0],BN_NIST_224_TOP);
        mask &= 0-(PTR_SIZE_INT)carry;
-       res   = (BN_ULONG *)(((PTR_SIZE_INT)c_d&~mask) |
+       res   = c_d;
+       res   = (BN_ULONG *)(((PTR_SIZE_INT)res&~mask) |
         ((PTR_SIZE_INT)r_d&mask));
        nist_cp_bn(r_d, res, BN_NIST_224_TOP);
        r->top = BN_NIST_224_TOP;
@@ -805,7 +813,8 @@ int BN_nist_mod_256(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 
        mask  = 0-(PTR_SIZE_INT)(*u.f)(c_d,r_d,_nist_p_256[0],BN_NIST_256_TOP);
        mask &= 0-(PTR_SIZE_INT)carry;
-       res   = (BN_ULONG *)(((PTR_SIZE_INT)c_d&~mask) |
+       res   = c_d;
+       res   = (BN_ULONG *)(((PTR_SIZE_INT)res&~mask) |
         ((PTR_SIZE_INT)r_d&mask));
        nist_cp_bn(r_d, res, BN_NIST_256_TOP);
        r->top = BN_NIST_256_TOP;
@@ -1026,7 +1035,8 @@ int BN_nist_mod_384(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 
        mask  = 0-(PTR_SIZE_INT)(*u.f)(c_d,r_d,_nist_p_384[0],BN_NIST_384_TOP);
        mask &= 0-(PTR_SIZE_INT)carry;
-       res   = (BN_ULONG *)(((PTR_SIZE_INT)c_d&~mask) |
+       res   = c_d;
+       res   = (BN_ULONG *)(((PTR_SIZE_INT)res&~mask) |
         ((PTR_SIZE_INT)r_d&mask));
        nist_cp_bn(r_d, res, BN_NIST_384_TOP);
        r->top = BN_NIST_384_TOP;
@@ -1092,7 +1102,8 @@ int BN_nist_mod_521(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 
        bn_add_words(r_d,r_d,t_d,BN_NIST_521_TOP);
        mask = 0-(PTR_SIZE_INT)bn_sub_words(t_d,r_d,_nist_p_521,BN_NIST_521_TOP);
-       res  = (BN_ULONG *)(((PTR_SIZE_INT)t_d&~mask) |
+       res  = t_d;
+       res  = (BN_ULONG *)(((PTR_SIZE_INT)res&~mask) |
         ((PTR_SIZE_INT)r_d&mask));
        nist_cp_bn(r_d,res,BN_NIST_521_TOP);
        r->top = BN_NIST_521_TOP;