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Commit ecf3220d authored by Eric Biggers's avatar Eric Biggers Committed by Herbert Xu
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crypto: chacha20 - Fix unaligned access when loading constants 



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: default avatarEric Biggers <ebiggers@google.com>
Acked-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent c3a53605

crypto/chacha20_generic.c

+4 −6
Original line number Diff line number Diff line
@@ -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];