Rename variable for better readability
@@ -1191,7 +1191,7 @@ int mbedtls_mpi_lt_mpi_ct( const mbedtls_mpi *X, const mbedtls_mpi *Y,
{
size_t i;
/* The value of any of these variables is either 0 or 1 at all times. */
- unsigned cond, done, sign_X, sign_Y;
+ unsigned cond, done, X_is_negative, Y_is_negative;
MPI_VALIDATE_RET( X != NULL );
MPI_VALIDATE_RET( Y != NULL );
@@ -1204,16 +1204,16 @@ int mbedtls_mpi_lt_mpi_ct( const mbedtls_mpi *X, const mbedtls_mpi *Y,
* Set sign_N to 1 if N >= 0, 0 if N < 0.
* We know that N->s == 1 if N >= 0 and N->s == -1 if N < 0.
*/
- sign_X = ( X->s & 2 ) >> 1;
- sign_Y = ( Y->s & 2 ) >> 1;
+ X_is_negative = ( X->s & 2 ) >> 1;
+ Y_is_negative = ( Y->s & 2 ) >> 1;
/*
* If the signs are different, then the positive operand is the bigger.
- * That is if X is negative (sign_X == 1), then X < Y is true and it is
- * false if X is positive (sign_X == 0).
+ * That is if X is negative (X_is_negative == 1), then X < Y is true and it
+ * is false if X is positive (X_is_negative == 0).
*/
- cond = ( sign_X ^ sign_Y );
- *ret = cond & sign_X;
+ cond = ( X_is_negative ^ Y_is_negative );
+ *ret = cond & X_is_negative;
/*
* This is a constant-time function. We might have the result, but we still
@@ -1230,7 +1230,7 @@ int mbedtls_mpi_lt_mpi_ct( const mbedtls_mpi *X, const mbedtls_mpi *Y,
* Again even if we can make a decision, we just mark the result and
* the fact that we are done and continue looping.
*/
- cond = ct_lt_mpi_uint( Y->p[i - 1], X->p[i - 1] ) & sign_X;
+ cond = ct_lt_mpi_uint( Y->p[i - 1], X->p[i - 1] ) & X_is_negative;
*ret |= cond & ( 1 - done );
done |= cond & ( 1 - done );
@@ -1241,7 +1241,8 @@ int mbedtls_mpi_lt_mpi_ct( const mbedtls_mpi *X, const mbedtls_mpi *Y,
* Again even if we can make a decision, we just mark the result and
* the fact that we are done and continue looping.
*/
- cond = ct_lt_mpi_uint( X->p[i - 1], Y->p[i - 1] ) & ( 1 - sign_X );
+ cond = ct_lt_mpi_uint( X->p[i - 1], Y->p[i - 1] )
+ & ( 1 - X_is_negative );
*ret |= cond & ( 1 - done );
done |= cond & ( 1 - done );
}
