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author | 2017-11-22 11:51:39 -0800 | |
---|---|---|
committer | 2017-11-29 17:33:33 +1100 | |
commit | 9f480faec58cd6197a007ea1dcac6b7c3daf1139 (patch) | |
tree | bd5107e627a9013bbbfc290ceccea218d9393f66 /drivers/char/random.c | |
parent | crypto: x86/chacha20 - Remove cra_alignmask (diff) | |
download | linux-9f480faec58cd6197a007ea1dcac6b7c3daf1139.tar.gz linux-9f480faec58cd6197a007ea1dcac6b7c3daf1139.tar.bz2 linux-9f480faec58cd6197a007ea1dcac6b7c3daf1139.zip |
crypto: chacha20 - Fix keystream alignment for chacha20_block()
When chacha20_block() outputs the keystream block, it uses 'u32' stores
directly. However, the callers (crypto/chacha20_generic.c and
drivers/char/random.c) declare the keystream buffer as a 'u8' array,
which is not guaranteed to have the needed alignment.
Fix it by having both callers declare the keystream as a 'u32' array.
For now this is preferable to switching over to the unaligned access
macros because chacha20_block() is only being used in cases where we can
easily control the alignment (stack buffers).
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/char/random.c')
-rw-r--r-- | drivers/char/random.c | 24 |
1 files changed, 12 insertions, 12 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index ec42c8bb9b0d..11304bbc78cc 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -431,9 +431,9 @@ static int crng_init = 0; static int crng_init_cnt = 0; #define CRNG_INIT_CNT_THRESH (2*CHACHA20_KEY_SIZE) static void _extract_crng(struct crng_state *crng, - __u8 out[CHACHA20_BLOCK_SIZE]); + __u32 out[CHACHA20_BLOCK_WORDS]); static void _crng_backtrack_protect(struct crng_state *crng, - __u8 tmp[CHACHA20_BLOCK_SIZE], int used); + __u32 tmp[CHACHA20_BLOCK_WORDS], int used); static void process_random_ready_list(void); static void _get_random_bytes(void *buf, int nbytes); @@ -817,7 +817,7 @@ static void crng_reseed(struct crng_state *crng, struct entropy_store *r) unsigned long flags; int i, num; union { - __u8 block[CHACHA20_BLOCK_SIZE]; + __u32 block[CHACHA20_BLOCK_WORDS]; __u32 key[8]; } buf; @@ -851,7 +851,7 @@ static void crng_reseed(struct crng_state *crng, struct entropy_store *r) } static void _extract_crng(struct crng_state *crng, - __u8 out[CHACHA20_BLOCK_SIZE]) + __u32 out[CHACHA20_BLOCK_WORDS]) { unsigned long v, flags; @@ -867,7 +867,7 @@ static void _extract_crng(struct crng_state *crng, spin_unlock_irqrestore(&crng->lock, flags); } -static void extract_crng(__u8 out[CHACHA20_BLOCK_SIZE]) +static void extract_crng(__u32 out[CHACHA20_BLOCK_WORDS]) { struct crng_state *crng = NULL; @@ -885,7 +885,7 @@ static void extract_crng(__u8 out[CHACHA20_BLOCK_SIZE]) * enough) to mutate the CRNG key to provide backtracking protection. */ static void _crng_backtrack_protect(struct crng_state *crng, - __u8 tmp[CHACHA20_BLOCK_SIZE], int used) + __u32 tmp[CHACHA20_BLOCK_WORDS], int used) { unsigned long flags; __u32 *s, *d; @@ -897,14 +897,14 @@ static void _crng_backtrack_protect(struct crng_state *crng, used = 0; } spin_lock_irqsave(&crng->lock, flags); - s = (__u32 *) &tmp[used]; + s = &tmp[used / sizeof(__u32)]; d = &crng->state[4]; for (i=0; i < 8; i++) *d++ ^= *s++; spin_unlock_irqrestore(&crng->lock, flags); } -static void crng_backtrack_protect(__u8 tmp[CHACHA20_BLOCK_SIZE], int used) +static void crng_backtrack_protect(__u32 tmp[CHACHA20_BLOCK_WORDS], int used) { struct crng_state *crng = NULL; @@ -920,7 +920,7 @@ static void crng_backtrack_protect(__u8 tmp[CHACHA20_BLOCK_SIZE], int used) static ssize_t extract_crng_user(void __user *buf, size_t nbytes) { ssize_t ret = 0, i = CHACHA20_BLOCK_SIZE; - __u8 tmp[CHACHA20_BLOCK_SIZE]; + __u32 tmp[CHACHA20_BLOCK_WORDS]; int large_request = (nbytes > 256); while (nbytes) { @@ -1507,7 +1507,7 @@ static void _warn_unseeded_randomness(const char *func_name, void *caller, */ static void _get_random_bytes(void *buf, int nbytes) { - __u8 tmp[CHACHA20_BLOCK_SIZE]; + __u32 tmp[CHACHA20_BLOCK_WORDS]; trace_get_random_bytes(nbytes, _RET_IP_); @@ -2114,7 +2114,7 @@ u64 get_random_u64(void) if (use_lock) read_lock_irqsave(&batched_entropy_reset_lock, flags); if (batch->position % ARRAY_SIZE(batch->entropy_u64) == 0) { - extract_crng((u8 *)batch->entropy_u64); + extract_crng((__u32 *)batch->entropy_u64); batch->position = 0; } ret = batch->entropy_u64[batch->position++]; @@ -2144,7 +2144,7 @@ u32 get_random_u32(void) if (use_lock) read_lock_irqsave(&batched_entropy_reset_lock, flags); if (batch->position % ARRAY_SIZE(batch->entropy_u32) == 0) { - extract_crng((u8 *)batch->entropy_u32); + extract_crng(batch->entropy_u32); batch->position = 0; } ret = batch->entropy_u32[batch->position++]; |