diff --git a/library/bignum.c b/library/bignum.c index 870365dd6..a238f8ce8 100644 --- a/library/bignum.c +++ b/library/bignum.c @@ -337,41 +337,12 @@ size_t mbedtls_mpi_lsb( const mbedtls_mpi *X ) return( 0 ); } -/* - * Count leading zero bits in a given integer - */ -static size_t mbedtls_clz( const mbedtls_mpi_uint x ) -{ - size_t j; - mbedtls_mpi_uint mask = (mbedtls_mpi_uint) 1 << (biL - 1); - - for( j = 0; j < biL; j++ ) - { - if( x & mask ) break; - - mask >>= 1; - } - - return j; -} - /* * Return the number of bits */ size_t mbedtls_mpi_bitlen( const mbedtls_mpi *X ) { - size_t i, j; - - if( X->n == 0 ) - return( 0 ); - - for( i = X->n - 1; i > 0; i-- ) - if( X->p[i] != 0 ) - break; - - j = biL - mbedtls_clz( X->p[i] ); - - return( ( i * biL ) + j ); + return mbedtls_mpi_core_bitlen( X->p, X->n ); } /* @@ -678,97 +649,6 @@ cleanup: } #endif /* MBEDTLS_FS_IO */ - -/* Convert a big-endian byte array aligned to the size of mbedtls_mpi_uint - * into the storage form used by mbedtls_mpi. */ - -static mbedtls_mpi_uint mpi_uint_bigendian_to_host_c( mbedtls_mpi_uint x ) -{ - uint8_t i; - unsigned char *x_ptr; - mbedtls_mpi_uint tmp = 0; - - for( i = 0, x_ptr = (unsigned char*) &x; i < ciL; i++, x_ptr++ ) - { - tmp <<= CHAR_BIT; - tmp |= (mbedtls_mpi_uint) *x_ptr; - } - - return( tmp ); -} - -static mbedtls_mpi_uint mpi_uint_bigendian_to_host( mbedtls_mpi_uint x ) -{ -#if defined(__BYTE_ORDER__) - -/* Nothing to do on bigendian systems. */ -#if ( __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ ) - return( x ); -#endif /* __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ */ - -#if ( __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ ) - -/* For GCC and Clang, have builtins for byte swapping. */ -#if defined(__GNUC__) && defined(__GNUC_PREREQ) -#if __GNUC_PREREQ(4,3) -#define have_bswap -#endif -#endif - -#if defined(__clang__) && defined(__has_builtin) -#if __has_builtin(__builtin_bswap32) && \ - __has_builtin(__builtin_bswap64) -#define have_bswap -#endif -#endif - -#if defined(have_bswap) - /* The compiler is hopefully able to statically evaluate this! */ - switch( sizeof(mbedtls_mpi_uint) ) - { - case 4: - return( __builtin_bswap32(x) ); - case 8: - return( __builtin_bswap64(x) ); - } -#endif -#endif /* __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ */ -#endif /* __BYTE_ORDER__ */ - - /* Fall back to C-based reordering if we don't know the byte order - * or we couldn't use a compiler-specific builtin. */ - return( mpi_uint_bigendian_to_host_c( x ) ); -} - -static void mpi_bigendian_to_host( mbedtls_mpi_uint * const p, size_t limbs ) -{ - mbedtls_mpi_uint *cur_limb_left; - mbedtls_mpi_uint *cur_limb_right; - if( limbs == 0 ) - return; - - /* - * Traverse limbs and - * - adapt byte-order in each limb - * - swap the limbs themselves. - * For that, simultaneously traverse the limbs from left to right - * and from right to left, as long as the left index is not bigger - * than the right index (it's not a problem if limbs is odd and the - * indices coincide in the last iteration). - */ - for( cur_limb_left = p, cur_limb_right = p + ( limbs - 1 ); - cur_limb_left <= cur_limb_right; - cur_limb_left++, cur_limb_right-- ) - { - mbedtls_mpi_uint tmp; - /* Note that if cur_limb_left == cur_limb_right, - * this code effectively swaps the bytes only once. */ - tmp = mpi_uint_bigendian_to_host( *cur_limb_left ); - *cur_limb_left = mpi_uint_bigendian_to_host( *cur_limb_right ); - *cur_limb_right = tmp; - } -} - /* * Import X from unsigned binary data, little endian * @@ -824,7 +704,7 @@ int mbedtls_mpi_read_binary( mbedtls_mpi *X, const unsigned char *buf, size_t bu Xp = (unsigned char*) X->p; memcpy( Xp + overhead, buf, buflen ); - mpi_bigendian_to_host( X->p, limbs ); + mbedtls_mpi_core_bigendian_to_host( X->p, limbs ); } cleanup: @@ -1530,7 +1410,7 @@ static mbedtls_mpi_uint mbedtls_int_div_int( mbedtls_mpi_uint u1, /* * Normalize the divisor, d, and dividend, u0, u1 */ - s = mbedtls_clz( d ); + s = mbedtls_mpi_core_clz( d ); d = d << s; u1 = u1 << s; @@ -2319,7 +2199,7 @@ static int mpi_fill_random_internal( memset( X->p, 0, overhead ); memset( (unsigned char *) X->p + limbs * ciL, 0, ( X->n - limbs ) * ciL ); MBEDTLS_MPI_CHK( f_rng( p_rng, (unsigned char *) X->p + overhead, n_bytes ) ); - mpi_bigendian_to_host( X->p, limbs ); + mbedtls_mpi_core_bigendian_to_host( X->p, limbs ); cleanup: return( ret ); diff --git a/library/bignum_core.h b/library/bignum_core.h index 8f48debe2..376a267de 100644 --- a/library/bignum_core.h +++ b/library/bignum_core.h @@ -42,6 +42,13 @@ #define BITS_TO_LIMBS(i) ( (i) / biL + ( (i) % biL != 0 ) ) #define CHARS_TO_LIMBS(i) ( (i) / ciL + ( (i) % ciL != 0 ) ) +size_t mbedtls_mpi_core_clz( const mbedtls_mpi_uint x ); + +size_t mbedtls_mpi_core_bitlen( const mbedtls_mpi_uint *X, size_t nx ); + +void mbedtls_mpi_core_bigendian_to_host( mbedtls_mpi_uint * const X, + size_t limbs ); + int mbedtls_mpi_core_read_le( mbedtls_mpi_uint *X, size_t nx, const unsigned char *buf, diff --git a/library/bignum_new.c b/library/bignum_new.c index e60d42892..6cbc8678c 100644 --- a/library/bignum_new.c +++ b/library/bignum_new.c @@ -43,7 +43,7 @@ /* * Count leading zero bits in a given integer */ -static size_t mpi_clz( const mbedtls_mpi_uint x ) +size_t mbedtls_mpi_core_clz( const mbedtls_mpi_uint x ) { size_t j; mbedtls_mpi_uint mask = (mbedtls_mpi_uint) 1 << (biL - 1); @@ -61,7 +61,7 @@ static size_t mpi_clz( const mbedtls_mpi_uint x ) /* * Return the number of bits */ -static size_t mpi_bitlen( const mbedtls_mpi_uint *X, size_t nx ) +size_t mbedtls_mpi_core_bitlen( const mbedtls_mpi_uint *X, size_t nx ) { size_t i, j; @@ -72,7 +72,7 @@ static size_t mpi_bitlen( const mbedtls_mpi_uint *X, size_t nx ) if( X[i] != 0 ) break; - j = biL - mpi_clz( X[i] ); + j = biL - mbedtls_mpi_core_clz( X[i] ); return( ( i * biL ) + j ); } @@ -150,7 +150,7 @@ int mbedtls_mpi_mod_modulus_setup( mbedtls_mpi_mod_modulus *m, m->p = X; m->n = nx; - m->plen = mpi_bitlen( X, nx ); + m->plen = mbedtls_mpi_core_bitlen( X, nx ); switch( ext_rep ) { @@ -264,8 +264,8 @@ static mbedtls_mpi_uint mpi_bigendian_to_host( mbedtls_mpi_uint x ) return( mpi_bigendian_to_host_c( x ) ); } -static void mpi_core_bigendian_to_host( mbedtls_mpi_uint * const X, - size_t limbs ) +void mbedtls_mpi_core_bigendian_to_host( mbedtls_mpi_uint * const X, + size_t limbs ) { mbedtls_mpi_uint *cur_limb_left; mbedtls_mpi_uint *cur_limb_right; @@ -350,7 +350,7 @@ int mbedtls_mpi_core_read_be( mbedtls_mpi_uint *X, Xp = (unsigned char*) X; memcpy( Xp + overhead, buf, buflen ); - mpi_core_bigendian_to_host( X, nx ); + mbedtls_mpi_core_bigendian_to_host( X, nx ); } cleanup: