From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Biggers Subject: [PATCH 1/5] crypto: chacha20 - Fix unaligned access when loading constants Date: Wed, 22 Nov 2017 11:51:35 -0800 Message-ID: <20171122195139.121269-2-ebiggers3@gmail.com> References: <20171122195139.121269-1-ebiggers3@gmail.com> Cc: Theodore Ts'o , "Jason A . Donenfeld" , Martin Willi , Ard Biesheuvel , linux-kernel@vger.kernel.org, Eric Biggers To: linux-crypto@vger.kernel.org, Herbert Xu Return-path: In-Reply-To: <20171122195139.121269-1-ebiggers3@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org From: Eric Biggers The four 32-bit constants for the initial state of ChaCha20 were loaded from a char array which is not guaranteed to have the needed alignment. Fix it by just assigning the constants directly instead. Signed-off-by: Eric Biggers --- crypto/chacha20_generic.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/crypto/chacha20_generic.c b/crypto/chacha20_generic.c index 4a45fa4890c0..ec84e7837aac 100644 --- a/crypto/chacha20_generic.c +++ b/crypto/chacha20_generic.c @@ -41,12 +41,10 @@ static void chacha20_docrypt(u32 *state, u8 *dst, const u8 *src, void crypto_chacha20_init(u32 *state, struct chacha20_ctx *ctx, u8 *iv) { - static const char constant[16] = "expand 32-byte k"; - - state[0] = le32_to_cpuvp(constant + 0); - state[1] = le32_to_cpuvp(constant + 4); - state[2] = le32_to_cpuvp(constant + 8); - state[3] = le32_to_cpuvp(constant + 12); + state[0] = 0x61707865; /* "expa" */ + state[1] = 0x3320646e; /* "nd 3" */ + state[2] = 0x79622d32; /* "2-by" */ + state[3] = 0x6b206574; /* "te k" */ state[4] = ctx->key[0]; state[5] = ctx->key[1]; state[6] = ctx->key[2]; -- 2.15.0.448.gf294e3d99a-goog