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| author | Eric Biggers <ebiggers@google.com> | 2018-09-12 05:05:10 +0200 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2018-09-21 07:24:50 +0200 |
| commit | a5e9f557098e54af44ade5d501379be18435bfbf (patch) | |
| tree | 4410647aaa269fd9a4e304851b06f83251b12853 /lib/chacha20.c | |
| parent | crypto: xts - Drop use of auxiliary buffer (diff) | |
| download | linux-a5e9f557098e54af44ade5d501379be18435bfbf.tar.xz linux-a5e9f557098e54af44ade5d501379be18435bfbf.zip | |
crypto: chacha20 - Fix chacha20_block() keystream alignment (again)
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>
Diffstat (limited to 'lib/chacha20.c')
| -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]++; } |