Re: [PATCH V2] crypto: Mark intermediary memory as clean
From: Stephan Mueller
Date: Mon Aug 18 2025 - 09:33:53 EST
Am Montag, 18. August 2025, 14:43:36 Mitteleuropäische Sommerzeit schrieb
Edward Adam Davis:
Hi Edward,
> On Mon, 18 Aug 2025 20:30:29 +0800, Herbert Xu wrote:
> > Their values are equal, so why use sizeof to calculate?
> > Similarly, "if (sizeof(intermediary) !=
> > crypto_shash_digestsize(desc->tfm)) {", why not just use
> > SHA3_256_DIGEST_SIZE?
>
> Hi Stephan Mueller, can you explain it?
If the question is why using sizeof(intermediary) instead of
SHA3_256_DIGEST_SIZE, then it is very trivial: I always want to avoid any kind
of double work. If for any reason the buffer size of intermediary changes, the
current code only requires *one* location to fix it.
When changing the branching condition to use SHA3_256_DIGEST_SIZE, we would
have to change *two* locations which is more error-prone than to change one.
This approach is my common coding style to try to minimize the possibilities
where inconsistencies can occur.
Ciao
Stephan