Fix an incorrect comment about fix_negative

We're subtracting multiples of 2^bits, not 2^(bits+32).

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
This commit is contained in:
Gilles Peskine 2021-04-03 21:40:11 +02:00
parent c3ccae7faf
commit 2c8cfcf59f

View File

@ -1048,13 +1048,13 @@ static inline void sub32( uint32_t *dst, uint32_t src, signed char *carry )
/* /*
* If the result is negative, we get it in the form * If the result is negative, we get it in the form
* c * 2^(bits + 32) + N, with c negative and N positive shorter than 'bits' * c * 2^bits + N, with c negative and N positive shorter than 'bits'
*/ */
static inline int fix_negative( mbedtls_mpi *N, signed char c, mbedtls_mpi *C, size_t bits ) static inline int fix_negative( mbedtls_mpi *N, signed char c, mbedtls_mpi *C, size_t bits )
{ {
int ret; int ret;
/* C = - c * 2^(bits + 32) */ /* C = - c * 2^bits */
#if !defined(MBEDTLS_HAVE_INT64) #if !defined(MBEDTLS_HAVE_INT64)
((void) bits); ((void) bits);
#else #else