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author | Eric Biggers <ebiggers@google.com> | 2018-09-11 20:05:10 -0700 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-11-20 18:47:11 +0100 |
commit | ad28c2ba4318e9c882647c57edd5a435edf57907 (patch) | |
tree | ba2fa067fde732a363196c57e9d09184a73cfb25 /lib | |
parent | af4749d23d46fc81c59e19a338081422ea779af1 (diff) | |
download | linux-stable-ad28c2ba4318e9c882647c57edd5a435edf57907.tar.gz linux-stable-ad28c2ba4318e9c882647c57edd5a435edf57907.tar.bz2 linux-stable-ad28c2ba4318e9c882647c57edd5a435edf57907.zip |
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 'lib')
-rw-r--r-- | lib/chacha20.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/lib/chacha20.c b/lib/chacha20.c index c1cc50fb68c9..d907fec6a9ed 100644 --- a/lib/chacha20.c +++ b/lib/chacha20.c @@ -16,9 +16,9 @@ #include <asm/unaligned.h> #include <crypto/chacha20.h> -void chacha20_block(u32 *state, u32 *stream) +void chacha20_block(u32 *state, u8 *stream) { - u32 x[16], *out = stream; + u32 x[16]; int i; for (i = 0; i < ARRAY_SIZE(x); i++) @@ -67,7 +67,7 @@ void chacha20_block(u32 *state, u32 *stream) } for (i = 0; i < ARRAY_SIZE(x); i++) - out[i] = cpu_to_le32(x[i] + state[i]); + put_unaligned_le32(x[i] + state[i], &stream[i * sizeof(u32)]); state[12]++; } |