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| author | Eric Biggers <ebiggers@google.com> | 2018-09-12 06:05:10 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-11-20 20:47:11 +0300 |
| commit | ad28c2ba4318e9c882647c57edd5a435edf57907 (patch) | |
| tree | ba2fa067fde732a363196c57e9d09184a73cfb25 /crypto | |
| parent | af4749d23d46fc81c59e19a338081422ea779af1 (diff) | |
| download | linux-ad28c2ba4318e9c882647c57edd5a435edf57907.tar.xz | |
crypto: chacha20 - Fix chacha20_block() keystream alignment (again)
[ 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>
Diffstat (limited to 'crypto')
| -rw-r--r-- | crypto/chacha20_generic.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/crypto/chacha20_generic.c b/crypto/chacha20_generic.c index e451c3cb6a56..3ae96587caf9 100644 --- a/crypto/chacha20_generic.c +++ b/crypto/chacha20_generic.c @@ -18,20 +18,21 @@ static void chacha20_docrypt(u32 *state, u8 *dst, const u8 *src, unsigned int bytes) { - u32 stream[CHACHA20_BLOCK_WORDS]; + /* aligned to potentially speed up crypto_xor() */ + u8 stream[CHACHA20_BLOCK_SIZE] __aligned(sizeof(long)); if (dst != src) memcpy(dst, src, bytes); while (bytes >= CHACHA20_BLOCK_SIZE) { chacha20_block(state, stream); - crypto_xor(dst, (const u8 *)stream, CHACHA20_BLOCK_SIZE); + crypto_xor(dst, stream, CHACHA20_BLOCK_SIZE); bytes -= CHACHA20_BLOCK_SIZE; dst += CHACHA20_BLOCK_SIZE; } if (bytes) { chacha20_block(state, stream); - crypto_xor(dst, (const u8 *)stream, bytes); + crypto_xor(dst, stream, bytes); } } |