Re: [PATCH v6 04/11] crypto: qce: skcipher: Return unsupported if any three keys are same for DES3 algorithms

On Sun, Feb 07, 2021 at 09:39:39AM -0500, Thara Gopinath wrote:

+	/*
+	 * The crypto engine does not support any two keys
+	 * being the same for triple des algorithms. The
+	 * verify_skcipher_des3_key does not check for all the
+	 * below conditions. Return -ENOKEY in case any two keys
+	 * are the same. Revisit to see if a fallback cipher
+	 * is needed to handle this condition.
+	 */
+	memcpy(_key, key, DES3_EDE_KEY_SIZE);
+	if (!((_key[0] ^ _key[2]) | (_key[1] ^ _key[3])) |
+	    !((_key[2] ^ _key[4]) | (_key[3] ^ _key[5])) |
+	    !((_key[0] ^ _key[4]) | (_key[1] ^ _key[5])))
+		return -ENOKEY;

This introduces a sparse warning:

  CHECK   ../drivers/crypto/qce/skcipher.c
../drivers/crypto/qce/skcipher.c:241:58: warning: dubious: !x | !y
../drivers/crypto/qce/skcipher.c:242:58: warning: dubious: x | !y

Please make sure that you test your patches with C=1 so that
you don't introduce new sparse warnings.

Thanks,
-- 
Email: Herbert Xu [off-list ref]
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt