Re: [PATCH 1/2] blkcipher: Copy iv from desc even for 0-len walks

[Herbert Xu]

On Sun, Dec 06, 2015 at 02:51:37AM +0100, Jason A. Donenfeld wrote:
> Some ciphers actually support encrypting zero length plaintexts. For
> example, many AEAD modes support this. The resulting ciphertext for
> those winds up being only the authentication tag, which is a result of
> the key, the iv, the additional data, and the fact that the plaintext
> had zero length. The blkcipher constructors won't copy the IV to the
> right place, however, when using a zero length input, resulting in
> some significant problems when ciphers call their initialization
> routines, only to find that the ->iv parameter is uninitialized. One
> such example of this would be using chacha20poly1305 with a zero length
> input, which then calls chacha20, which calls the key setup routine,
> which eventually OOPSes due to the uninitialized ->iv member.
> 
> Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx>

Applied to crypto.
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Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
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