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Differential D20242 Diff 57331 head/sys/libkern/arc4random.c

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head/sys/libkern/arc4random.c

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void void
arc4rand(void *ptr, u_int len, int reseed) arc4rand(void *ptr, u_int len, int reseed)
{ {
struct chacha20_s *chacha20; struct chacha20_s *chacha20;
struct timeval tv; struct timeval tv;
u_int length; u_int length;
u_int8_t *p; u_int8_t *p;
if (reseed || atomic_cmpset_int(&arc4rand_iniseed_state, ARC4_ENTR_HAVE, ARC4_ENTR_SEED)) if (__predict_false(reseed ||
(arc4rand_iniseed_state == ARC4_ENTR_HAVE &&
atomic_cmpset_int(&arc4rand_iniseed_state, ARC4_ENTR_HAVE, ARC4_ENTR_SEED))))
CHACHA20_FOREACH(chacha20) CHACHA20_FOREACH(chacha20)
chacha20_randomstir(chacha20); chacha20_randomstir(chacha20);
chacha20 = &chacha20inst[curcpu];
getmicrouptime(&tv); getmicrouptime(&tv);
chacha20 = &chacha20inst[curcpu];
/* We may get unlucky and be migrated off this CPU, but that is expected to be infrequent */ /* We may get unlucky and be migrated off this CPU, but that is expected to be infrequent */
if ((chacha20->numbytes > CHACHA20_RESEED_BYTES) || (tv.tv_sec > chacha20->t_reseed)) if ((chacha20->numbytes > CHACHA20_RESEED_BYTES) || (tv.tv_sec > chacha20->t_reseed))
chacha20_randomstir(chacha20); chacha20_randomstir(chacha20);
mtx_lock(&chacha20->mtx);
p = ptr; p = ptr;
mtx_lock(&chacha20->mtx);
while (len) { while (len) {
length = MIN(CHACHA20_BUFFER_SIZE, len); length = MIN(CHACHA20_BUFFER_SIZE, len);
chacha_encrypt_bytes(&chacha20->ctx, chacha20->m_buffer, p, length); chacha_encrypt_bytes(&chacha20->ctx, chacha20->m_buffer, p, length);
p += length; p += length;
len -= length; len -= length;
chacha20->numbytes += length; chacha20->numbytes += length;
if (chacha20->numbytes > CHACHA20_RESEED_BYTES) { if (chacha20->numbytes > CHACHA20_RESEED_BYTES) {
mtx_unlock(&chacha20->mtx); mtx_unlock(&chacha20->mtx);
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