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Commit 7eabda80 authored by Eric Biggers's avatar Eric Biggers Committed by Jaegeuk Kim
Browse files

fscrypt: verify that the crypto_skcipher has the correct ivsize 

As a sanity check, verify that the allocated crypto_skcipher actually
has the ivsize that fscrypt is assuming it has.  This will always be the
case unless there's a bug.  But if there ever is such a bug (e.g. like
there was in earlier versions of the ESSIV conversion patch [1]) it's
preferable for it to be immediately obvious, and not rely on the
ciphertext verification tests failing due to uninitialized IV bytes.

[1] https://lkml.kernel.org/linux-crypto/20190702215517.GA69157@gmail.com/

Link: https://lore.kernel.org/r/20191209203918.225691-1-ebiggers@kernel.org


Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
parent 17b10a9c

fs/crypto/keysetup.c

+4 −0
Original line number Diff line number Diff line
@@ -91,6 +91,10 @@ struct crypto_skcipher *fscrypt_allocate_skcipher(struct fscrypt_mode *mode, 
		pr_info("fscrypt: %s using implementation \"%s\"\n",

			mode->friendly_name, crypto_skcipher_driver_name(tfm));

	}

	if (WARN_ON(crypto_skcipher_ivsize(tfm) != mode->ivsize)) {

		err = -EINVAL;

		goto err_free_tfm;

	}

	crypto_skcipher_set_flags(tfm, CRYPTO_TFM_REQ_WEAK_KEY);

	err = crypto_skcipher_setkey(tfm, raw_key, mode->keysize);

	if (err)