diff options
Diffstat (limited to 'stdlib')
| -rw-r--r-- | stdlib/rng.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/stdlib/rng.c b/stdlib/rng.c index bf23cb74..befc535a 100644 --- a/stdlib/rng.c +++ b/stdlib/rng.c @@ -18,7 +18,7 @@ #include "chacha.h" -public _Thread_local RNG_t default_rng; +public _Thread_local RNG_t default_rng = NULL; struct RNGState_t { chacha_ctx chacha; @@ -69,22 +69,26 @@ static void rekey(RNG_t rng) chacha_ivsetup(&rng->chacha, rng->random_bytes + KEYSZ); explicit_bzero(rng->random_bytes, KEYSZ + IVSZ); rng->unused_bytes = sizeof(rng->random_bytes) - KEYSZ - IVSZ; + assert(rng->unused_bytes <= sizeof(rng->random_bytes)); } static void random_bytes(RNG_t rng, uint8_t *dest, size_t needed) { while (needed > 0) { - if (rng->unused_bytes > 0) { + assert(rng->unused_bytes <= sizeof(rng->random_bytes)); + if (rng->unused_bytes == 0) { + rekey(rng); + } else { size_t to_get = MIN(needed, rng->unused_bytes); + assert(to_get <= rng->unused_bytes); uint8_t *keystream = rng->random_bytes + sizeof(rng->random_bytes) - rng->unused_bytes; memcpy(dest, keystream, to_get); memset(keystream, 0, to_get); dest += to_get; needed -= to_get; rng->unused_bytes -= to_get; + assert(rng->unused_bytes <= sizeof(rng->random_bytes)); } - if (rng->unused_bytes == 0) - rekey(rng); } } |