> diff --git a/include/crypto/xts.h b/include/crypto/xts.h
...
> @@ -35,6 +35,13 @@ static inline int xts_verify_key(struct crypto_skcipher
> *tfm,
> if (keylen % 2)
> return -EINVAL;
>
> + /*
> + * In FIPS mode only a combined key length of either 256 or
> + * 512 bits is allowed, c.f. FIPS 140-3 IG C.I.
> + */
> + if (fips_enabled && keylen != 32 && keylen != 64)
> + return -EINVAL;
> +
> /* ensure that the AES and tweak key are not identical */
> if ((fips_enabled || (crypto_skcipher_get_flags(tfm) &
> CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)) &&
> --
> 2.38.0
There's another function in the same file called xts_check_key()
that is used by some of the hardware drivers:
arch/s390/crypto/paes_s390.c: * xts_check_key verifies the key length is not odd and makes
[that references it in the comment but actually calls xts_verify_key in the code]
drivers/crypto/axis/artpec6_crypto.c: ret = xts_check_key(&cipher->base, key, keylen);
drivers/crypto/cavium/cpt/cptvf_algs.c: err = xts_check_key(tfm, key, keylen);
drivers/crypto/cavium/nitrox/nitrox_skcipher.c: ret = xts_check_key(tfm, key, keylen);
drivers/crypto/ccree/cc_cipher.c: xts_check_key(tfm, key, keylen)) {
drivers/crypto/marvell/octeontx/otx_cptvf_algs.c: ret = xts_check_key(crypto_skcipher_tfm(tfm), key, keylen);
drivers/crypto/marvell/octeontx2/otx2_cptvf_algs.c: ret = xts_check_key(crypto_skcipher_tfm(tfm), key, keylen);
drivers/crypto/atmel-aes.c: err = xts_check_key(crypto_skcipher_tfm(tfm), key, keylen);
It already has one check qualified by fips_enabled:
/* ensure that the AES and tweak key are not identical */
if (fips_enabled && !crypto_memneq(key, key + (keylen / 2), keylen / 2))
return -EINVAL;
Should that implement the same key length restrictions?
