Put local variables and buffers in a struct
This reduces the impact of the code size increase due to the addition
of calls to mbedtls_platform_zeroize.
Signed-off-by: gabor-mezei-arm <gabor.mezei@arm.com>
diff --git a/library/sha1.c b/library/sha1.c
index 65841ee..7e6981d 100644
--- a/library/sha1.c
+++ b/library/sha1.c
@@ -147,32 +147,37 @@
int mbedtls_internal_sha1_process( mbedtls_sha1_context *ctx,
const unsigned char data[64] )
{
- uint32_t temp, W[16], A, B, C, D, E;
+ struct
+ {
+ uint32_t temp, W[16], A, B, C, D, E;
+ } local;
- GET_UINT32_BE( W[ 0], data, 0 );
- GET_UINT32_BE( W[ 1], data, 4 );
- GET_UINT32_BE( W[ 2], data, 8 );
- GET_UINT32_BE( W[ 3], data, 12 );
- GET_UINT32_BE( W[ 4], data, 16 );
- GET_UINT32_BE( W[ 5], data, 20 );
- GET_UINT32_BE( W[ 6], data, 24 );
- GET_UINT32_BE( W[ 7], data, 28 );
- GET_UINT32_BE( W[ 8], data, 32 );
- GET_UINT32_BE( W[ 9], data, 36 );
- GET_UINT32_BE( W[10], data, 40 );
- GET_UINT32_BE( W[11], data, 44 );
- GET_UINT32_BE( W[12], data, 48 );
- GET_UINT32_BE( W[13], data, 52 );
- GET_UINT32_BE( W[14], data, 56 );
- GET_UINT32_BE( W[15], data, 60 );
+ GET_UINT32_BE( local.W[ 0], data, 0 );
+ GET_UINT32_BE( local.W[ 1], data, 4 );
+ GET_UINT32_BE( local.W[ 2], data, 8 );
+ GET_UINT32_BE( local.W[ 3], data, 12 );
+ GET_UINT32_BE( local.W[ 4], data, 16 );
+ GET_UINT32_BE( local.W[ 5], data, 20 );
+ GET_UINT32_BE( local.W[ 6], data, 24 );
+ GET_UINT32_BE( local.W[ 7], data, 28 );
+ GET_UINT32_BE( local.W[ 8], data, 32 );
+ GET_UINT32_BE( local.W[ 9], data, 36 );
+ GET_UINT32_BE( local.W[10], data, 40 );
+ GET_UINT32_BE( local.W[11], data, 44 );
+ GET_UINT32_BE( local.W[12], data, 48 );
+ GET_UINT32_BE( local.W[13], data, 52 );
+ GET_UINT32_BE( local.W[14], data, 56 );
+ GET_UINT32_BE( local.W[15], data, 60 );
#define S(x,n) ((x << n) | ((x & 0xFFFFFFFF) >> (32 - n)))
#define R(t) \
( \
- temp = W[( t - 3 ) & 0x0F] ^ W[( t - 8 ) & 0x0F] ^ \
- W[( t - 14 ) & 0x0F] ^ W[ t & 0x0F], \
- ( W[t & 0x0F] = S(temp,1) ) \
+ local.temp = local.W[( t - 3 ) & 0x0F] ^ \
+ local.W[( t - 8 ) & 0x0F] ^ \
+ local.W[( t - 14 ) & 0x0F] ^ \
+ local.W[ t & 0x0F], \
+ ( local.W[t & 0x0F] = S(local.temp,1) ) \
)
#define P(a,b,c,d,e,x) \
@@ -180,35 +185,35 @@
e += S(a,5) + F(b,c,d) + K + x; b = S(b,30); \
}
- A = ctx->state[0];
- B = ctx->state[1];
- C = ctx->state[2];
- D = ctx->state[3];
- E = ctx->state[4];
+ local.A = ctx->state[0];
+ local.B = ctx->state[1];
+ local.C = ctx->state[2];
+ local.D = ctx->state[3];
+ local.E = ctx->state[4];
#define F(x,y,z) (z ^ (x & (y ^ z)))
#define K 0x5A827999
- P( A, B, C, D, E, W[0] );
- P( E, A, B, C, D, W[1] );
- P( D, E, A, B, C, W[2] );
- P( C, D, E, A, B, W[3] );
- P( B, C, D, E, A, W[4] );
- P( A, B, C, D, E, W[5] );
- P( E, A, B, C, D, W[6] );
- P( D, E, A, B, C, W[7] );
- P( C, D, E, A, B, W[8] );
- P( B, C, D, E, A, W[9] );
- P( A, B, C, D, E, W[10] );
- P( E, A, B, C, D, W[11] );
- P( D, E, A, B, C, W[12] );
- P( C, D, E, A, B, W[13] );
- P( B, C, D, E, A, W[14] );
- P( A, B, C, D, E, W[15] );
- P( E, A, B, C, D, R(16) );
- P( D, E, A, B, C, R(17) );
- P( C, D, E, A, B, R(18) );
- P( B, C, D, E, A, R(19) );
+ P( local.A, local.B, local.C, local.D, local.E, local.W[0] );
+ P( local.E, local.A, local.B, local.C, local.D, local.W[1] );
+ P( local.D, local.E, local.A, local.B, local.C, local.W[2] );
+ P( local.C, local.D, local.E, local.A, local.B, local.W[3] );
+ P( local.B, local.C, local.D, local.E, local.A, local.W[4] );
+ P( local.A, local.B, local.C, local.D, local.E, local.W[5] );
+ P( local.E, local.A, local.B, local.C, local.D, local.W[6] );
+ P( local.D, local.E, local.A, local.B, local.C, local.W[7] );
+ P( local.C, local.D, local.E, local.A, local.B, local.W[8] );
+ P( local.B, local.C, local.D, local.E, local.A, local.W[9] );
+ P( local.A, local.B, local.C, local.D, local.E, local.W[10] );
+ P( local.E, local.A, local.B, local.C, local.D, local.W[11] );
+ P( local.D, local.E, local.A, local.B, local.C, local.W[12] );
+ P( local.C, local.D, local.E, local.A, local.B, local.W[13] );
+ P( local.B, local.C, local.D, local.E, local.A, local.W[14] );
+ P( local.A, local.B, local.C, local.D, local.E, local.W[15] );
+ P( local.E, local.A, local.B, local.C, local.D, R(16) );
+ P( local.D, local.E, local.A, local.B, local.C, R(17) );
+ P( local.C, local.D, local.E, local.A, local.B, R(18) );
+ P( local.B, local.C, local.D, local.E, local.A, R(19) );
#undef K
#undef F
@@ -216,26 +221,26 @@
#define F(x,y,z) (x ^ y ^ z)
#define K 0x6ED9EBA1
- P( A, B, C, D, E, R(20) );
- P( E, A, B, C, D, R(21) );
- P( D, E, A, B, C, R(22) );
- P( C, D, E, A, B, R(23) );
- P( B, C, D, E, A, R(24) );
- P( A, B, C, D, E, R(25) );
- P( E, A, B, C, D, R(26) );
- P( D, E, A, B, C, R(27) );
- P( C, D, E, A, B, R(28) );
- P( B, C, D, E, A, R(29) );
- P( A, B, C, D, E, R(30) );
- P( E, A, B, C, D, R(31) );
- P( D, E, A, B, C, R(32) );
- P( C, D, E, A, B, R(33) );
- P( B, C, D, E, A, R(34) );
- P( A, B, C, D, E, R(35) );
- P( E, A, B, C, D, R(36) );
- P( D, E, A, B, C, R(37) );
- P( C, D, E, A, B, R(38) );
- P( B, C, D, E, A, R(39) );
+ P( local.A, local.B, local.C, local.D, local.E, R(20) );
+ P( local.E, local.A, local.B, local.C, local.D, R(21) );
+ P( local.D, local.E, local.A, local.B, local.C, R(22) );
+ P( local.C, local.D, local.E, local.A, local.B, R(23) );
+ P( local.B, local.C, local.D, local.E, local.A, R(24) );
+ P( local.A, local.B, local.C, local.D, local.E, R(25) );
+ P( local.E, local.A, local.B, local.C, local.D, R(26) );
+ P( local.D, local.E, local.A, local.B, local.C, R(27) );
+ P( local.C, local.D, local.E, local.A, local.B, R(28) );
+ P( local.B, local.C, local.D, local.E, local.A, R(29) );
+ P( local.A, local.B, local.C, local.D, local.E, R(30) );
+ P( local.E, local.A, local.B, local.C, local.D, R(31) );
+ P( local.D, local.E, local.A, local.B, local.C, R(32) );
+ P( local.C, local.D, local.E, local.A, local.B, R(33) );
+ P( local.B, local.C, local.D, local.E, local.A, R(34) );
+ P( local.A, local.B, local.C, local.D, local.E, R(35) );
+ P( local.E, local.A, local.B, local.C, local.D, R(36) );
+ P( local.D, local.E, local.A, local.B, local.C, R(37) );
+ P( local.C, local.D, local.E, local.A, local.B, R(38) );
+ P( local.B, local.C, local.D, local.E, local.A, R(39) );
#undef K
#undef F
@@ -243,26 +248,26 @@
#define F(x,y,z) ((x & y) | (z & (x | y)))
#define K 0x8F1BBCDC
- P( A, B, C, D, E, R(40) );
- P( E, A, B, C, D, R(41) );
- P( D, E, A, B, C, R(42) );
- P( C, D, E, A, B, R(43) );
- P( B, C, D, E, A, R(44) );
- P( A, B, C, D, E, R(45) );
- P( E, A, B, C, D, R(46) );
- P( D, E, A, B, C, R(47) );
- P( C, D, E, A, B, R(48) );
- P( B, C, D, E, A, R(49) );
- P( A, B, C, D, E, R(50) );
- P( E, A, B, C, D, R(51) );
- P( D, E, A, B, C, R(52) );
- P( C, D, E, A, B, R(53) );
- P( B, C, D, E, A, R(54) );
- P( A, B, C, D, E, R(55) );
- P( E, A, B, C, D, R(56) );
- P( D, E, A, B, C, R(57) );
- P( C, D, E, A, B, R(58) );
- P( B, C, D, E, A, R(59) );
+ P( local.A, local.B, local.C, local.D, local.E, R(40) );
+ P( local.E, local.A, local.B, local.C, local.D, R(41) );
+ P( local.D, local.E, local.A, local.B, local.C, R(42) );
+ P( local.C, local.D, local.E, local.A, local.B, R(43) );
+ P( local.B, local.C, local.D, local.E, local.A, R(44) );
+ P( local.A, local.B, local.C, local.D, local.E, R(45) );
+ P( local.E, local.A, local.B, local.C, local.D, R(46) );
+ P( local.D, local.E, local.A, local.B, local.C, R(47) );
+ P( local.C, local.D, local.E, local.A, local.B, R(48) );
+ P( local.B, local.C, local.D, local.E, local.A, R(49) );
+ P( local.A, local.B, local.C, local.D, local.E, R(50) );
+ P( local.E, local.A, local.B, local.C, local.D, R(51) );
+ P( local.D, local.E, local.A, local.B, local.C, R(52) );
+ P( local.C, local.D, local.E, local.A, local.B, R(53) );
+ P( local.B, local.C, local.D, local.E, local.A, R(54) );
+ P( local.A, local.B, local.C, local.D, local.E, R(55) );
+ P( local.E, local.A, local.B, local.C, local.D, R(56) );
+ P( local.D, local.E, local.A, local.B, local.C, R(57) );
+ P( local.C, local.D, local.E, local.A, local.B, R(58) );
+ P( local.B, local.C, local.D, local.E, local.A, R(59) );
#undef K
#undef F
@@ -270,44 +275,38 @@
#define F(x,y,z) (x ^ y ^ z)
#define K 0xCA62C1D6
- P( A, B, C, D, E, R(60) );
- P( E, A, B, C, D, R(61) );
- P( D, E, A, B, C, R(62) );
- P( C, D, E, A, B, R(63) );
- P( B, C, D, E, A, R(64) );
- P( A, B, C, D, E, R(65) );
- P( E, A, B, C, D, R(66) );
- P( D, E, A, B, C, R(67) );
- P( C, D, E, A, B, R(68) );
- P( B, C, D, E, A, R(69) );
- P( A, B, C, D, E, R(70) );
- P( E, A, B, C, D, R(71) );
- P( D, E, A, B, C, R(72) );
- P( C, D, E, A, B, R(73) );
- P( B, C, D, E, A, R(74) );
- P( A, B, C, D, E, R(75) );
- P( E, A, B, C, D, R(76) );
- P( D, E, A, B, C, R(77) );
- P( C, D, E, A, B, R(78) );
- P( B, C, D, E, A, R(79) );
+ P( local.A, local.B, local.C, local.D, local.E, R(60) );
+ P( local.E, local.A, local.B, local.C, local.D, R(61) );
+ P( local.D, local.E, local.A, local.B, local.C, R(62) );
+ P( local.C, local.D, local.E, local.A, local.B, R(63) );
+ P( local.B, local.C, local.D, local.E, local.A, R(64) );
+ P( local.A, local.B, local.C, local.D, local.E, R(65) );
+ P( local.E, local.A, local.B, local.C, local.D, R(66) );
+ P( local.D, local.E, local.A, local.B, local.C, R(67) );
+ P( local.C, local.D, local.E, local.A, local.B, R(68) );
+ P( local.B, local.C, local.D, local.E, local.A, R(69) );
+ P( local.A, local.B, local.C, local.D, local.E, R(70) );
+ P( local.E, local.A, local.B, local.C, local.D, R(71) );
+ P( local.D, local.E, local.A, local.B, local.C, R(72) );
+ P( local.C, local.D, local.E, local.A, local.B, R(73) );
+ P( local.B, local.C, local.D, local.E, local.A, R(74) );
+ P( local.A, local.B, local.C, local.D, local.E, R(75) );
+ P( local.E, local.A, local.B, local.C, local.D, R(76) );
+ P( local.D, local.E, local.A, local.B, local.C, R(77) );
+ P( local.C, local.D, local.E, local.A, local.B, R(78) );
+ P( local.B, local.C, local.D, local.E, local.A, R(79) );
#undef K
#undef F
- ctx->state[0] += A;
- ctx->state[1] += B;
- ctx->state[2] += C;
- ctx->state[3] += D;
- ctx->state[4] += E;
+ ctx->state[0] += local.A;
+ ctx->state[1] += local.B;
+ ctx->state[2] += local.C;
+ ctx->state[3] += local.D;
+ ctx->state[4] += local.E;
/* Zeroise buffers and variables to clear sensitive data from memory. */
- mbedtls_zeroize( &A, sizeof( A ) );
- mbedtls_zeroize( &B, sizeof( B ) );
- mbedtls_zeroize( &C, sizeof( C ) );
- mbedtls_zeroize( &D, sizeof( D ) );
- mbedtls_zeroize( &E, sizeof( E ) );
- mbedtls_zeroize( &W, sizeof( W ) );
- mbedtls_zeroize( &temp, sizeof( temp ) );
+ mbedtls_zeroize( &local, sizeof( local ) );
return( 0 );
}