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>
diff --git a/library/psa_crypto_aead.c b/library/psa_crypto_aead.c
index ac4297e..29dbede 100644
--- a/library/psa_crypto_aead.c
+++ b/library/psa_crypto_aead.c
@@ -447,6 +447,9 @@
#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 )