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/md5.c b/library/md5.c
index 9c75cae..125406f 100644
--- a/library/md5.c
+++ b/library/md5.c
@@ -146,132 +146,131 @@
int mbedtls_internal_md5_process( mbedtls_md5_context *ctx,
const unsigned char data[64] )
{
- uint32_t X[16], A, B, C, D;
+ struct
+ {
+ uint32_t X[16], A, B, C, D;
+ } local;
- GET_UINT32_LE( X[ 0], data, 0 );
- GET_UINT32_LE( X[ 1], data, 4 );
- GET_UINT32_LE( X[ 2], data, 8 );
- GET_UINT32_LE( X[ 3], data, 12 );
- GET_UINT32_LE( X[ 4], data, 16 );
- GET_UINT32_LE( X[ 5], data, 20 );
- GET_UINT32_LE( X[ 6], data, 24 );
- GET_UINT32_LE( X[ 7], data, 28 );
- GET_UINT32_LE( X[ 8], data, 32 );
- GET_UINT32_LE( X[ 9], data, 36 );
- GET_UINT32_LE( X[10], data, 40 );
- GET_UINT32_LE( X[11], data, 44 );
- GET_UINT32_LE( X[12], data, 48 );
- GET_UINT32_LE( X[13], data, 52 );
- GET_UINT32_LE( X[14], data, 56 );
- GET_UINT32_LE( X[15], data, 60 );
+ GET_UINT32_LE( local.X[ 0], data, 0 );
+ GET_UINT32_LE( local.X[ 1], data, 4 );
+ GET_UINT32_LE( local.X[ 2], data, 8 );
+ GET_UINT32_LE( local.X[ 3], data, 12 );
+ GET_UINT32_LE( local.X[ 4], data, 16 );
+ GET_UINT32_LE( local.X[ 5], data, 20 );
+ GET_UINT32_LE( local.X[ 6], data, 24 );
+ GET_UINT32_LE( local.X[ 7], data, 28 );
+ GET_UINT32_LE( local.X[ 8], data, 32 );
+ GET_UINT32_LE( local.X[ 9], data, 36 );
+ GET_UINT32_LE( local.X[10], data, 40 );
+ GET_UINT32_LE( local.X[11], data, 44 );
+ GET_UINT32_LE( local.X[12], data, 48 );
+ GET_UINT32_LE( local.X[13], data, 52 );
+ GET_UINT32_LE( local.X[14], data, 56 );
+ GET_UINT32_LE( local.X[15], data, 60 );
#define S(x,n) ((x << n) | ((x & 0xFFFFFFFF) >> (32 - n)))
#define P(a,b,c,d,k,s,t) \
{ \
- a += F(b,c,d) + X[k] + t; a = S(a,s) + b; \
+ a += F(b,c,d) + local.X[k] + t; a = S(a,s) + b; \
}
- A = ctx->state[0];
- B = ctx->state[1];
- C = ctx->state[2];
- D = ctx->state[3];
+ local.A = ctx->state[0];
+ local.B = ctx->state[1];
+ local.C = ctx->state[2];
+ local.D = ctx->state[3];
#define F(x,y,z) (z ^ (x & (y ^ z)))
- P( A, B, C, D, 0, 7, 0xD76AA478 );
- P( D, A, B, C, 1, 12, 0xE8C7B756 );
- P( C, D, A, B, 2, 17, 0x242070DB );
- P( B, C, D, A, 3, 22, 0xC1BDCEEE );
- P( A, B, C, D, 4, 7, 0xF57C0FAF );
- P( D, A, B, C, 5, 12, 0x4787C62A );
- P( C, D, A, B, 6, 17, 0xA8304613 );
- P( B, C, D, A, 7, 22, 0xFD469501 );
- P( A, B, C, D, 8, 7, 0x698098D8 );
- P( D, A, B, C, 9, 12, 0x8B44F7AF );
- P( C, D, A, B, 10, 17, 0xFFFF5BB1 );
- P( B, C, D, A, 11, 22, 0x895CD7BE );
- P( A, B, C, D, 12, 7, 0x6B901122 );
- P( D, A, B, C, 13, 12, 0xFD987193 );
- P( C, D, A, B, 14, 17, 0xA679438E );
- P( B, C, D, A, 15, 22, 0x49B40821 );
+ P( local.A, local.B, local.C, local.D, 0, 7, 0xD76AA478 );
+ P( local.D, local.A, local.B, local.C, 1, 12, 0xE8C7B756 );
+ P( local.C, local.D, local.A, local.B, 2, 17, 0x242070DB );
+ P( local.B, local.C, local.D, local.A, 3, 22, 0xC1BDCEEE );
+ P( local.A, local.B, local.C, local.D, 4, 7, 0xF57C0FAF );
+ P( local.D, local.A, local.B, local.C, 5, 12, 0x4787C62A );
+ P( local.C, local.D, local.A, local.B, 6, 17, 0xA8304613 );
+ P( local.B, local.C, local.D, local.A, 7, 22, 0xFD469501 );
+ P( local.A, local.B, local.C, local.D, 8, 7, 0x698098D8 );
+ P( local.D, local.A, local.B, local.C, 9, 12, 0x8B44F7AF );
+ P( local.C, local.D, local.A, local.B, 10, 17, 0xFFFF5BB1 );
+ P( local.B, local.C, local.D, local.A, 11, 22, 0x895CD7BE );
+ P( local.A, local.B, local.C, local.D, 12, 7, 0x6B901122 );
+ P( local.D, local.A, local.B, local.C, 13, 12, 0xFD987193 );
+ P( local.C, local.D, local.A, local.B, 14, 17, 0xA679438E );
+ P( local.B, local.C, local.D, local.A, 15, 22, 0x49B40821 );
#undef F
#define F(x,y,z) (y ^ (z & (x ^ y)))
- P( A, B, C, D, 1, 5, 0xF61E2562 );
- P( D, A, B, C, 6, 9, 0xC040B340 );
- P( C, D, A, B, 11, 14, 0x265E5A51 );
- P( B, C, D, A, 0, 20, 0xE9B6C7AA );
- P( A, B, C, D, 5, 5, 0xD62F105D );
- P( D, A, B, C, 10, 9, 0x02441453 );
- P( C, D, A, B, 15, 14, 0xD8A1E681 );
- P( B, C, D, A, 4, 20, 0xE7D3FBC8 );
- P( A, B, C, D, 9, 5, 0x21E1CDE6 );
- P( D, A, B, C, 14, 9, 0xC33707D6 );
- P( C, D, A, B, 3, 14, 0xF4D50D87 );
- P( B, C, D, A, 8, 20, 0x455A14ED );
- P( A, B, C, D, 13, 5, 0xA9E3E905 );
- P( D, A, B, C, 2, 9, 0xFCEFA3F8 );
- P( C, D, A, B, 7, 14, 0x676F02D9 );
- P( B, C, D, A, 12, 20, 0x8D2A4C8A );
+ P( local.A, local.B, local.C, local.D, 1, 5, 0xF61E2562 );
+ P( local.D, local.A, local.B, local.C, 6, 9, 0xC040B340 );
+ P( local.C, local.D, local.A, local.B, 11, 14, 0x265E5A51 );
+ P( local.B, local.C, local.D, local.A, 0, 20, 0xE9B6C7AA );
+ P( local.A, local.B, local.C, local.D, 5, 5, 0xD62F105D );
+ P( local.D, local.A, local.B, local.C, 10, 9, 0x02441453 );
+ P( local.C, local.D, local.A, local.B, 15, 14, 0xD8A1E681 );
+ P( local.B, local.C, local.D, local.A, 4, 20, 0xE7D3FBC8 );
+ P( local.A, local.B, local.C, local.D, 9, 5, 0x21E1CDE6 );
+ P( local.D, local.A, local.B, local.C, 14, 9, 0xC33707D6 );
+ P( local.C, local.D, local.A, local.B, 3, 14, 0xF4D50D87 );
+ P( local.B, local.C, local.D, local.A, 8, 20, 0x455A14ED );
+ P( local.A, local.B, local.C, local.D, 13, 5, 0xA9E3E905 );
+ P( local.D, local.A, local.B, local.C, 2, 9, 0xFCEFA3F8 );
+ P( local.C, local.D, local.A, local.B, 7, 14, 0x676F02D9 );
+ P( local.B, local.C, local.D, local.A, 12, 20, 0x8D2A4C8A );
#undef F
#define F(x,y,z) (x ^ y ^ z)
- P( A, B, C, D, 5, 4, 0xFFFA3942 );
- P( D, A, B, C, 8, 11, 0x8771F681 );
- P( C, D, A, B, 11, 16, 0x6D9D6122 );
- P( B, C, D, A, 14, 23, 0xFDE5380C );
- P( A, B, C, D, 1, 4, 0xA4BEEA44 );
- P( D, A, B, C, 4, 11, 0x4BDECFA9 );
- P( C, D, A, B, 7, 16, 0xF6BB4B60 );
- P( B, C, D, A, 10, 23, 0xBEBFBC70 );
- P( A, B, C, D, 13, 4, 0x289B7EC6 );
- P( D, A, B, C, 0, 11, 0xEAA127FA );
- P( C, D, A, B, 3, 16, 0xD4EF3085 );
- P( B, C, D, A, 6, 23, 0x04881D05 );
- P( A, B, C, D, 9, 4, 0xD9D4D039 );
- P( D, A, B, C, 12, 11, 0xE6DB99E5 );
- P( C, D, A, B, 15, 16, 0x1FA27CF8 );
- P( B, C, D, A, 2, 23, 0xC4AC5665 );
+ P( local.A, local.B, local.C, local.D, 5, 4, 0xFFFA3942 );
+ P( local.D, local.A, local.B, local.C, 8, 11, 0x8771F681 );
+ P( local.C, local.D, local.A, local.B, 11, 16, 0x6D9D6122 );
+ P( local.B, local.C, local.D, local.A, 14, 23, 0xFDE5380C );
+ P( local.A, local.B, local.C, local.D, 1, 4, 0xA4BEEA44 );
+ P( local.D, local.A, local.B, local.C, 4, 11, 0x4BDECFA9 );
+ P( local.C, local.D, local.A, local.B, 7, 16, 0xF6BB4B60 );
+ P( local.B, local.C, local.D, local.A, 10, 23, 0xBEBFBC70 );
+ P( local.A, local.B, local.C, local.D, 13, 4, 0x289B7EC6 );
+ P( local.D, local.A, local.B, local.C, 0, 11, 0xEAA127FA );
+ P( local.C, local.D, local.A, local.B, 3, 16, 0xD4EF3085 );
+ P( local.B, local.C, local.D, local.A, 6, 23, 0x04881D05 );
+ P( local.A, local.B, local.C, local.D, 9, 4, 0xD9D4D039 );
+ P( local.D, local.A, local.B, local.C, 12, 11, 0xE6DB99E5 );
+ P( local.C, local.D, local.A, local.B, 15, 16, 0x1FA27CF8 );
+ P( local.B, local.C, local.D, local.A, 2, 23, 0xC4AC5665 );
#undef F
#define F(x,y,z) (y ^ (x | ~z))
- P( A, B, C, D, 0, 6, 0xF4292244 );
- P( D, A, B, C, 7, 10, 0x432AFF97 );
- P( C, D, A, B, 14, 15, 0xAB9423A7 );
- P( B, C, D, A, 5, 21, 0xFC93A039 );
- P( A, B, C, D, 12, 6, 0x655B59C3 );
- P( D, A, B, C, 3, 10, 0x8F0CCC92 );
- P( C, D, A, B, 10, 15, 0xFFEFF47D );
- P( B, C, D, A, 1, 21, 0x85845DD1 );
- P( A, B, C, D, 8, 6, 0x6FA87E4F );
- P( D, A, B, C, 15, 10, 0xFE2CE6E0 );
- P( C, D, A, B, 6, 15, 0xA3014314 );
- P( B, C, D, A, 13, 21, 0x4E0811A1 );
- P( A, B, C, D, 4, 6, 0xF7537E82 );
- P( D, A, B, C, 11, 10, 0xBD3AF235 );
- P( C, D, A, B, 2, 15, 0x2AD7D2BB );
- P( B, C, D, A, 9, 21, 0xEB86D391 );
+ P( local.A, local.B, local.C, local.D, 0, 6, 0xF4292244 );
+ P( local.D, local.A, local.B, local.C, 7, 10, 0x432AFF97 );
+ P( local.C, local.D, local.A, local.B, 14, 15, 0xAB9423A7 );
+ P( local.B, local.C, local.D, local.A, 5, 21, 0xFC93A039 );
+ P( local.A, local.B, local.C, local.D, 12, 6, 0x655B59C3 );
+ P( local.D, local.A, local.B, local.C, 3, 10, 0x8F0CCC92 );
+ P( local.C, local.D, local.A, local.B, 10, 15, 0xFFEFF47D );
+ P( local.B, local.C, local.D, local.A, 1, 21, 0x85845DD1 );
+ P( local.A, local.B, local.C, local.D, 8, 6, 0x6FA87E4F );
+ P( local.D, local.A, local.B, local.C, 15, 10, 0xFE2CE6E0 );
+ P( local.C, local.D, local.A, local.B, 6, 15, 0xA3014314 );
+ P( local.B, local.C, local.D, local.A, 13, 21, 0x4E0811A1 );
+ P( local.A, local.B, local.C, local.D, 4, 6, 0xF7537E82 );
+ P( local.D, local.A, local.B, local.C, 11, 10, 0xBD3AF235 );
+ P( local.C, local.D, local.A, local.B, 2, 15, 0x2AD7D2BB );
+ P( local.B, local.C, local.D, local.A, 9, 21, 0xEB86D391 );
#undef F
- ctx->state[0] += A;
- ctx->state[1] += B;
- ctx->state[2] += C;
- ctx->state[3] += D;
+ ctx->state[0] += local.A;
+ ctx->state[1] += local.B;
+ ctx->state[2] += local.C;
+ ctx->state[3] += local.D;
/* Zeroise variables to clear sensitive data from memory. */
- mbedtls_zeroize( &X, sizeof( X ) );
- mbedtls_zeroize( &A, sizeof( A ) );
- mbedtls_zeroize( &B, sizeof( B ) );
- mbedtls_zeroize( &C, sizeof( C ) );
- mbedtls_zeroize( &D, sizeof( D ) );
+ mbedtls_zeroize( &local, sizeof( local ) );
return( 0 );
}