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| author | Damien Miller <djm@mindrot.org> | 2000-08-30 00:40:09 +0200 |
|---|---|---|
| committer | Damien Miller <djm@mindrot.org> | 2000-08-30 00:40:09 +0200 |
| commit | c30d35ce3234371c20a388d81b4bafd389d3019f (patch) | |
| tree | 700aa922a381fa51c8334f9d09cc8481d0619db3 /bsd-arc4random.c | |
| parent | - (djm) Compile warning fixes from Mark Miller <markm@swoon.net> (diff) | |
| download | openssh-c30d35ce3234371c20a388d81b4bafd389d3019f.tar.xz openssh-c30d35ce3234371c20a388d81b4bafd389d3019f.zip | |
- (djm) Periodically rekey arc4random
- (djm) Clean up diff against OpenBSD.
Diffstat (limited to 'bsd-arc4random.c')
| -rw-r--r-- | bsd-arc4random.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/bsd-arc4random.c b/bsd-arc4random.c index 4c2f0854f..a1f515461 100644 --- a/bsd-arc4random.c +++ b/bsd-arc4random.c @@ -33,6 +33,12 @@ #ifndef HAVE_ARC4RANDOM +/* Size of key to use */ +#define SEED_SIZE 20 + +/* Number of bytes to reseed after */ +#define REKEY_BYTES (1 >> 18) + static int rc4_ready = 0; static RC4_KEY rc4; @@ -40,27 +46,30 @@ unsigned int arc4random(void) { unsigned int r = 0; - if (!rc4_ready) + if (rc4_ready <= 0) arc4random_stir(); RC4(&rc4, sizeof(r), (unsigned char *)&r, (unsigned char *)&r); + + rc4_ready -= sizeof(r); return(r); } void arc4random_stir(void) { - unsigned char rand_buf[32]; + unsigned char rand_buf[SEED_SIZE]; memset(&rc4, 0, sizeof(rc4)); seed_rng(); + RAND_bytes(rand_buf, sizeof(rand_buf)); RC4_set_key(&rc4, sizeof(rand_buf), rand_buf); memset(rand_buf, 0, sizeof(rand_buf)); - rc4_ready = 1; + rc4_ready = REKEY_BYTES; } #endif /* !HAVE_ARC4RANDOM */ |