Kasatkin, Dmitry <dmitry.kasatkin@xxxxxxxxx> wrote:
> Hi,
>
> I have noticed very odd behavior with hmac calculation on my dual
> core, 4 HTs PC.
> I am using async hash API to to calculate hmac over the page.
> I am using "hmac(sha1)" and the same key to calculate different pages.
>
> I have a work queue, which calculates the hmac like...
>
> int()
> {
> tfm = crypto_alloc_ahash(...);
> }
>
> work_task()
> {
> crypto_ahash_setkey(tfm, key, keylen);
> crypto_ahash_digest(req);
> }
>
> HMAC result "sometimes" is incorrect.
Is your tfm shared by multiple instances of work_task? The key
is a property of the tfm, so you cannot have multiple users of a
tfm all changing keys at the same time.
The correct usage model allowing parallel use is to dedicate a
tfm to each key.
Cheers,
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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