mod_p224 now endian-neutral

This commit is contained in:
Manuel Pégourié-Gonnard 2013-10-21 17:51:45 +02:00
parent e783f06f73
commit a47e7058ea
2 changed files with 38 additions and 21 deletions

View file

@ -142,6 +142,7 @@ typedef uint32_t t_udbl;
typedef unsigned int t_udbl __attribute__((mode(TI)));
#define POLARSSL_HAVE_UDBL
#else
#define POLARSSL_HAVE_INT32
typedef int32_t t_sint;
typedef uint32_t t_uint;
#if ( defined(_MSC_VER) && defined(_M_IX86) )

View file

@ -545,8 +545,6 @@ cleanup:
#if defined(POLARSSL_ECP_DP_SECP521R1_ENABLED)
/* For now, prototype version for 32-bit or little-endian 64 bits only */
static inline void add32( uint32_t *dst, uint32_t src, signed char *carry )
{
*dst += src;
@ -559,24 +557,44 @@ static inline void sub32( uint32_t *dst, uint32_t src, signed char *carry )
*dst -= src;
}
#define A( i ) ( ((uint32_t *) N->p)[i] )
#define ADD( i ) add32( p, A( i ), &c );
#define SUB( i ) sub32( p, A( i ), &c );
#if defined(POLARSSL_HAVE_INT16) || defined(POLARSSL_HAVE_INT8)
#error "Currently not supported, WIP"
#elif defined(POLARSSL_HAVE_INT32)
#define A( j ) N->p[j]
#define STORE32 N->p[i] = cur;
#else /* 64-bit */
#define A( j ) j % 2 ? (uint32_t)( N->p[j/2] >> 32 ) : (uint32_t)( N->p[j/2] )
#define STORE32 \
if( i % 2 ) { \
N->p[i/2] &= 0x00000000FFFFFFFF; \
N->p[i/2] |= ((uint64_t) cur) << 32; \
} else { \
N->p[i/2] &= 0xFFFFFFFF00000000; \
N->p[i/2] |= (uint64_t) cur; \
}
#endif
#define ADD( j ) add32( &cur, A( j ), &c );
#define SUB( j ) sub32( &cur, A( j ), &c );
#define LOAD32 cur = A( i );
#define FIRST c = 0; i = 0; LOAD32;
#define NEXT \
p++; \
cc = c; \
c = 0; \
STORE32; i++; LOAD32; \
cc = c; c = 0; \
if( cc < 0 ) \
sub32( p, -cc, &c ); \
sub32( &cur, -cc, &c ); \
else \
add32( p, cc, &c );
add32( &cur, cc, &c );
#define LAST \
p++; \
*p = c > 0 ? c : 0; /* see fix_negative */ \
while( ++p < end ) \
*p = 0; \
#define LAST \
STORE32; i++; \
cur = c > 0 ? c : 0; STORE32; /* see fix_negative */ \
cur = 0; \
while( ++i < N->n * sizeof( t_uint ) / sizeof( uint32_t ) ) \
STORE32; \
if( c < 0 ) fix_negative( N, c, bits );
/*
@ -607,16 +625,14 @@ static int ecp_mod_p224( mpi *N )
{
int ret;
signed char c, cc;
uint32_t *p, *end;
uint32_t cur;
size_t i;
size_t bits = 224;
/* Make sure we have the correct number of blocks */
/* Make sure we have enough blocks */
MPI_CHK( mpi_grow( N, bits * 2 / 8 / sizeof( t_uint ) ) );
/* Currently assuming 32-bit ints, or 64-bits little-endian */
p = (uint32_t *) N->p;
end = (uint32_t *) (N->p + N->n);
FIRST;
SUB( 7 ); SUB( 11 ); NEXT; // A0 += -A7 - A11
SUB( 8 ); SUB( 12 ); NEXT; // A1 += -A8 - A12
SUB( 9 ); SUB( 13 ); NEXT; // A2 += -A9 - A13