Add comment to non-obvious code guard

Ad and body lengths can only be too big on builds where size_t is bigger
than 32 bits. This checking code therefore generates always true
comparison warnings on 32 bit platforms, and thus had to be guarded.

Signed-off-by: Paul Elliott <paul.elliott@arm.com>
This commit is contained in:
Paul Elliott 2021-05-10 19:33:03 +01:00
parent 6edb7473db
commit ef29e17a94

View File

@ -447,6 +447,9 @@ psa_status_t mbedtls_psa_aead_set_lengths( mbedtls_psa_aead_operation_t
#if defined(MBEDTLS_PSA_BUILTIN_ALG_GCM)
if( operation->alg == PSA_ALG_GCM )
{
/* Lengths can only be too large for GCM if size_t is bigger than 32
* bits. Without the guard this code will generate warnings on 32bit
builds */
#if SIZE_MAX > UINT32_MAX
if( ( (uint64_t) ad_length ) >> 61 != 0 ||
( (uint64_t) plaintext_length ) > 0xFFFFFFFE0ull )