crypto: xts - consolidate sanity check for keys
The patch centralizes the XTS key check logic into the service function
xts_check_key which is invoked from the different XTS implementations.
With this, the XTS implementations in ARM, ARM64, PPC and S390 have now
a sanity check for the XTS keys similar to the other arches.
In addition, this service function received a check to ensure that the
key != the tweak key which is mandated by FIPS 140-2 IG A.9. As the
check is not present in the standards defining XTS, it is only enforced
in FIPS mode of the kernel.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/xts.c b/crypto/xts.c
index f6fd43f..26ba583 100644
--- a/crypto/xts.c
+++ b/crypto/xts.c
@@ -35,16 +35,11 @@
{
struct priv *ctx = crypto_tfm_ctx(parent);
struct crypto_cipher *child = ctx->tweak;
- u32 *flags = &parent->crt_flags;
int err;
- /* key consists of keys of equal size concatenated, therefore
- * the length must be even */
- if (keylen % 2) {
- /* tell the user why there was an error */
- *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
- return -EINVAL;
- }
+ err = xts_check_key(parent, key, keylen);
+ if (err)
+ return err;
/* we need two cipher instances: one to compute the initial 'tweak'
* by encrypting the IV (usually the 'plain' iv) and the other