Use basename of objxref.pl not whole path in generated header.

[oweals/openssl.git] / crypto / bn / bn_nist.c

diff --git a/crypto/bn/bn_nist.c b/crypto/bn/bn_nist.c
index 716dc81825379c258b7e75b88ae44ac3d96d2ce9..2ca5b0139111f76352b3d2c08ba6232056efb942 100644 (file)
--- a/crypto/bn/bn_nist.c
+++ b/crypto/bn/bn_nist.c
@@ -73,12 +73,22 @@ static const BN_ULONG _nist_p_192[][BN_NIST_192_TOP] = {
        {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},
        {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},
@@ -91,6 +101,12 @@ static const BN_ULONG _nist_p_256[][BN_NIST_256_TOP] = {
        {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},
@@ -103,24 +119,48 @@ static const BN_ULONG _nist_p_384[][BN_NIST_384_TOP] = {
        {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[][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},
@@ -133,6 +173,12 @@ static const BN_ULONG _nist_p_256[][BN_NIST_256_TOP] = {
        {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},
@@ -145,10 +191,24 @@ static const BN_ULONG _nist_p_384[][BN_NIST_384_TOP] = {
        {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
@@ -231,7 +291,9 @@ static void nist_cp_bn_0(BN_ULONG *buf, BN_ULONG *a, int top, int max)
        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--)
@@ -293,11 +355,16 @@ 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)
@@ -321,14 +388,14 @@ int BN_nist_mod_192(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
        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);
+       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, r_d, t_d, BN_NIST_192_TOP);
+       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, r_d, t_d, BN_NIST_192_TOP);
+       carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP);
 
        if (carry > 0)
-               carry = bn_sub_words(r_d,r_d,_nist_p_192[carry-1],BN_NIST_192_TOP);
+               carry = (int)bn_sub_words(r_d,r_d,_nist_p_192[carry-1],BN_NIST_192_TOP);
        else
                carry = 1;
 
@@ -373,11 +440,17 @@ int BN_nist_mod_224(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
                *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*224+BN_BITS2-1)/BN_BITS2)
-               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)
@@ -409,13 +482,13 @@ 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);
 #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);
+       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, r_d, t_d, BN_NIST_224_TOP);
+       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);
-       carry -= bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP);
+       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);
-       carry -= bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP);
+       carry -= (int)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);
@@ -423,7 +496,7 @@ int BN_nist_mod_224(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
        u.f = bn_sub_words;
        if (carry > 0)
                {
-               carry = bn_sub_words(r_d,r_d,_nist_p_224[carry-1],BN_NIST_224_TOP);
+               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
@@ -436,7 +509,7 @@ int BN_nist_mod_224(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
                 * 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);
+               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);
                }
@@ -478,11 +551,16 @@ int BN_nist_mod_256(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
                *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)
@@ -509,7 +587,7 @@ int BN_nist_mod_256(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
        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);
+       carry = (int)bn_add_words(t_d, t_d, c_d, BN_NIST_256_TOP);
        /* left shift */
                {
                register BN_ULONG *ap,t,c;
@@ -524,33 +602,33 @@ int BN_nist_mod_256(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
                carry <<= 1;
                carry  |= c;
                }
-       carry += bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);
+       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, r_d, t_d, BN_NIST_256_TOP);
+       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, r_d, t_d, BN_NIST_256_TOP);
+       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);
-       carry -= bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
+       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);
-       carry -= bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
+       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);
-       carry -= bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
+       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);
-       carry -= bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
+       carry -= (int)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);
+               carry = (int)bn_sub_words(r_d,r_d,_nist_p_256[carry-1],BN_NIST_256_TOP);
        else if (carry < 0)
                {
-               carry = bn_add_words(r_d,r_d,_nist_p_256[-carry-1],BN_NIST_256_TOP);
+               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);
                }
@@ -595,11 +673,17 @@ int BN_nist_mod_384(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
                *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)
@@ -637,39 +721,39 @@ int BN_nist_mod_384(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
                        }
                *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);
        /*S2 */
-       carry += bn_add_words(r_d, r_d, buf, BN_NIST_384_TOP);
+       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, r_d, t_d, BN_NIST_384_TOP);
+       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, r_d, t_d, BN_NIST_384_TOP);
+       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, r_d, t_d, BN_NIST_384_TOP);
+       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, r_d, t_d, BN_NIST_384_TOP);
+       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);
-       carry -= bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
+       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);
-       carry -= bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
+       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);
-       carry -= bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
+       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 = bn_sub_words(r_d,r_d,_nist_p_384[carry-1],BN_NIST_384_TOP);
+               carry = (int)bn_sub_words(r_d,r_d,_nist_p_384[carry-1],BN_NIST_384_TOP);
        else if (carry < 0)
                {
-               carry = bn_add_words(r_d,r_d,_nist_p_384[-carry-1],BN_NIST_384_TOP);
+               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);
                }
@@ -698,11 +782,16 @@ int BN_nist_mod_521(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
                 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) || BN_num_bits(a)>2*521)
-               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);
 
        i = BN_ucmp(field, a);
        if (i == 0)