From a208fa8f33031b9e0aba44c7d1b7e68eb0cbd29e Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Wed, 3 Jan 2018 11:16:26 -0800 Subject: crypto: hash - annotate algorithms taking optional key We need to consistently enforce that keyed hashes cannot be used without setting the key. To do this we need a reliable way to determine whether a given hash algorithm is keyed or not. AF_ALG currently does this by checking for the presence of a ->setkey() method. However, this is actually slightly broken because the CRC-32 algorithms implement ->setkey() but can also be used without a key. (The CRC-32 "key" is not actually a cryptographic key but rather represents the initial state. If not overridden, then a default initial state is used.) Prepare to fix this by introducing a flag CRYPTO_ALG_OPTIONAL_KEY which indicates that the algorithm has a ->setkey() method, but it is not required to be called. Then set it on all the CRC-32 algorithms. The same also applies to the Adler-32 implementation in Lustre. Also, the cryptd and mcryptd templates have to pass through the flag from their underlying algorithm. Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu --- include/linux/crypto.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux/crypto.h') diff --git a/include/linux/crypto.h b/include/linux/crypto.h index 231e59f90d32..d2e33a90825b 100644 --- a/include/linux/crypto.h +++ b/include/linux/crypto.h @@ -106,6 +106,12 @@ */ #define CRYPTO_ALG_INTERNAL 0x00002000 +/* + * Set if the algorithm has a ->setkey() method but can be used without + * calling it first, i.e. there is a default key. + */ +#define CRYPTO_ALG_OPTIONAL_KEY 0x00004000 + /* * Transform masks and values (for crt_flags). */ -- cgit v1.2.3-59-g8ed1b