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| author | ache <ache@FreeBSD.org> | 2013-04-19 00:30:52 +0000 |
|---|---|---|
| committer | ache <ache@FreeBSD.org> | 2013-04-19 00:30:52 +0000 |
| commit | 60f7807df19873ac8b9fce428ca4198735d92067 (patch) | |
| tree | fa25310a8dd89ca7a6e6ae0ff9bec9876bb60c74 /sys/libkern | |
| parent | 1110825468efffa72f05077e3a42f5e5fa6963ec (diff) | |
| download | FreeBSD-src-60f7807df19873ac8b9fce428ca4198735d92067.zip FreeBSD-src-60f7807df19873ac8b9fce428ca4198735d92067.tar.gz | |
Attempt to mitigate poor initialization of arc4 by one-shot
reinitialization from yarrow right after good entropy is harvested.
Approved by: secteam (delphij)
MFC after: 1 week
Diffstat (limited to 'sys/libkern')
| -rw-r--r-- | sys/libkern/arc4random.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/sys/libkern/arc4random.c b/sys/libkern/arc4random.c index 4fcd74d..62ace2c 100644 --- a/sys/libkern/arc4random.c +++ b/sys/libkern/arc4random.c @@ -24,6 +24,8 @@ __FBSDID("$FreeBSD$"); #define ARC4_RESEED_SECONDS 300 #define ARC4_KEYBYTES (256 / 8) +int arc4rand_iniseed_state = ARC4_ENTR_NONE; + static u_int8_t arc4_i, arc4_j; static int arc4_numruns = 0; static u_int8_t arc4_sbox[256]; @@ -130,7 +132,8 @@ arc4rand(void *ptr, u_int len, int reseed) struct timeval tv; getmicrouptime(&tv); - if (reseed || + if (atomic_cmpset_int(&arc4rand_iniseed_state, ARC4_ENTR_HAVE, + ARC4_ENTR_SEED) || reseed || (arc4_numruns > ARC4_RESEED_BYTES) || (tv.tv_sec > arc4_t_reseed)) arc4_randomstir(); |
