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| author | Keelan Cannoo <96436249+Keelan10@users.noreply.github.com> | 2022-09-12 23:12:47 +0400 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2022-09-12 22:12:47 +0300 |
| commit | bb41229ff4dbd62084994c6b0b2052a321fd0ccf (patch) | |
| tree | bc7584f90469e826bf29df90408af7a4c2a1df3f /arc4random.c | |
| parent | 039e8d96a476a93874576d808242157698496f04 (diff) | |
| download | libevent-bb41229ff4dbd62084994c6b0b2052a321fd0ccf.tar.gz | |
Make rekey interval less predictable (#1331)
Diffstat (limited to 'arc4random.c')
| -rw-r--r-- | arc4random.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/arc4random.c b/arc4random.c index c36e3c11..b5f66b4c 100644 --- a/arc4random.c +++ b/arc4random.c @@ -75,8 +75,7 @@ /* Add platform entropy 32 bytes (256 bits) at a time. */ #define ADD_ENTROPY 32 -/* Re-seed from the platform RNG after generating this many bytes. */ -#define BYTES_BEFORE_RESEED 1600000 +#define REKEY_BASE (1024*1024) /* NB. should be a power of 2 */ struct arc4_stream { unsigned char i; @@ -343,10 +342,13 @@ arc4_seed(void) return ok ? 0 : -1; } +static inline unsigned int +arc4_getword(void); static int arc4_stir(void) { int i; + ARC4RANDOM_UINT32 rekey_fuzz; if (!rs_initialized) { arc4_init(); @@ -377,7 +379,9 @@ arc4_stir(void) for (i = 0; i < 12*256; i++) (void)arc4_getbyte(); - arc4_count = BYTES_BEFORE_RESEED; + rekey_fuzz = arc4_getword(); + /* rekey interval should not be predictable */ + arc4_count = REKEY_BASE + (rekey_fuzz % REKEY_BASE); return 0; } |