Local readability improvements
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/library/bignum_core.c b/library/bignum_core.c
index 14f2f5a..b7d6b62 100644
--- a/library/bignum_core.c
+++ b/library/bignum_core.c
@@ -605,23 +605,23 @@
mbedtls_mpi_uint *Wtable,
mbedtls_mpi_uint *temp )
{
- /* pointers to table entries */
- mbedtls_mpi_uint *Wcur, *Wlast, *W1;
-
/* W[0] = 1 (in Montgomery presentation) */
memset( Wtable, 0, AN_limbs * ciL );
Wtable[0] = 1;
mbedtls_mpi_core_montmul( Wtable, Wtable, RR, AN_limbs, N, AN_limbs, mm, temp );
- Wcur = Wtable + AN_limbs;
+
/* W[1] = A * R^2 * R^-1 mod N = A * R mod N */
- memcpy( Wcur, A, AN_limbs * ciL );
- mbedtls_mpi_core_montmul( Wcur, Wcur, RR, AN_limbs, N, AN_limbs, mm, temp );
- W1 = Wcur;
- Wcur += AN_limbs;
+ mbedtls_mpi_uint *W1 = Wtable + AN_limbs;
+ mbedtls_mpi_core_montmul( W1, A, RR, AN_limbs, N, AN_limbs, mm, temp );
+
/* W[i+1] = W[i] * W[1], i >= 2 */
- Wlast = W1;
- for( size_t i = 2; i < welem; i++, Wlast += AN_limbs, Wcur += AN_limbs )
- mbedtls_mpi_core_montmul( Wcur, Wlast, W1, AN_limbs, N, AN_limbs, mm, temp );
+ mbedtls_mpi_uint *Wprev = W1;
+ for( size_t i = 2; i < welem; i++ )
+ {
+ mbedtls_mpi_uint *Wcur = Wprev + AN_limbs;
+ mbedtls_mpi_core_montmul( Wcur, Wprev, W1, AN_limbs, N, AN_limbs, mm, temp );
+ Wprev = Wcur;
+ }
}
int mbedtls_mpi_core_exp_mod( mbedtls_mpi_uint *X,
@@ -702,15 +702,17 @@
mbedtls_mpi_core_ct_uint_table_lookup( Wselect, Wtable,
AN_limbs, welem, window );
mbedtls_mpi_core_montmul( X, X, Wselect, AN_limbs, N, AN_limbs, mm, temp );
- window = window_bits = 0;
+ window = 0;
+ window_bits = 0;
continue;
}
/* Load next exponent limb if necessary */
if( limb_bits_remaining == 0 )
{
- cur_limb = *--E;
- E_limbs--;
+ --E;
+ cur_limb = *E;
+ --E_limbs;
limb_bits_remaining = biL;
}
@@ -721,8 +723,8 @@
window <<= 1;
window |= ( cur_limb >> ( biL - 1 ) );
cur_limb <<= 1;
- window_bits++;
- limb_bits_remaining--;
+ ++window_bits;
+ --limb_bits_remaining;
}
/* Convert X back to normal presentation */