70e975501f
[ Upstream commit a5e9f557098e54af44ade5d501379be18435bfbf ]
In commit 9f480faec58c ("crypto: chacha20 - Fix keystream alignment for
chacha20_block()"), I had missed that chacha20_block() can be called
directly on the buffer passed to get_random_bytes(), which can have any
alignment. So, while my commit didn't break anything, it didn't fully
solve the alignment problems.
Revert my solution and just update chacha20_block() to use
put_unaligned_le32(), so the output buffer need not be aligned.
This is simpler, and on many CPUs it's the same speed.
But, I kept the 'tmp' buffers in extract_crng_user() and
_get_random_bytes() 4-byte aligned, since that alignment is actually
needed for _crng_backtrack_protect() too.
Reported-by: Stephan Müller <smueller@chronox.de>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
42 lines
1.0 KiB
C
42 lines
1.0 KiB
C
/*
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* Common values for the ChaCha20 algorithm
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*/
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#ifndef _CRYPTO_CHACHA20_H
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#define _CRYPTO_CHACHA20_H
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#include <linux/types.h>
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#include <linux/crypto.h>
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#define CHACHA20_IV_SIZE 16
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#define CHACHA20_KEY_SIZE 32
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#define CHACHA20_BLOCK_SIZE 64
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struct chacha20_ctx {
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u32 key[8];
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};
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void chacha20_block(u32 *state, u8 *stream);
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void crypto_chacha20_init(u32 *state, struct chacha20_ctx *ctx, u8 *iv);
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int crypto_chacha20_setkey(struct crypto_tfm *tfm, const u8 *key,
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unsigned int keysize);
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int crypto_chacha20_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
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struct scatterlist *src, unsigned int nbytes);
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enum chacha_constants { /* expand 32-byte k */
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CHACHA_CONSTANT_EXPA = 0x61707865U,
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CHACHA_CONSTANT_ND_3 = 0x3320646eU,
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CHACHA_CONSTANT_2_BY = 0x79622d32U,
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CHACHA_CONSTANT_TE_K = 0x6b206574U
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};
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static inline void chacha_init_consts(u32 *state)
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{
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state[0] = CHACHA_CONSTANT_EXPA;
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state[1] = CHACHA_CONSTANT_ND_3;
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state[2] = CHACHA_CONSTANT_2_BY;
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state[3] = CHACHA_CONSTANT_TE_K;
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}
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#endif
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