diff options
Diffstat (limited to 'sys/libkern')
| -rw-r--r-- | sys/libkern/arc4random.c | 117 |
1 files changed, 80 insertions, 37 deletions
diff --git a/sys/libkern/arc4random.c b/sys/libkern/arc4random.c index d230aa2..ccda6ad 100644 --- a/sys/libkern/arc4random.c +++ b/sys/libkern/arc4random.c @@ -19,6 +19,8 @@ __FBSDID("$FreeBSD$"); #include <sys/lock.h> #include <sys/mutex.h> #include <sys/time.h> +#include <sys/smp.h> +#include <sys/malloc.h> #define ARC4_RESEED_BYTES 65536 #define ARC4_RESEED_SECONDS 300 @@ -26,13 +28,23 @@ __FBSDID("$FreeBSD$"); 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]; -static time_t arc4_t_reseed; -static struct mtx arc4_mtx; +MALLOC_DEFINE(M_ARC4RANDOM, "arc4random", "arc4random structures"); -static u_int8_t arc4_randbyte(void); +struct arc4_s { + struct mtx mtx; + u_int8_t i, j; + int numruns; + u_int8_t sbox[256]; + time_t t_reseed; + +} __aligned(CACHE_LINE_SIZE); + +static struct arc4_s *arc4inst = NULL; + +#define ARC4_FOREACH(_arc4) \ + for (_arc4 = &arc4inst[0]; _arc4 <= &arc4inst[mp_maxid]; _arc4++) + +static u_int8_t arc4_randbyte(struct arc4_s *arc4); static __inline void arc4_swap(u_int8_t *a, u_int8_t *b) @@ -48,7 +60,7 @@ arc4_swap(u_int8_t *a, u_int8_t *b) * Stir our S-box. */ static void -arc4_randomstir(void) +arc4_randomstir(struct arc4_s* arc4) { u_int8_t key[ARC4_KEYBYTES]; int n; @@ -60,15 +72,15 @@ arc4_randomstir(void) */ (void)read_random(key, ARC4_KEYBYTES); getmicrouptime(&tv_now); - mtx_lock(&arc4_mtx); + mtx_lock(&arc4->mtx); for (n = 0; n < 256; n++) { - arc4_j = (arc4_j + arc4_sbox[n] + key[n]) % 256; - arc4_swap(&arc4_sbox[n], &arc4_sbox[arc4_j]); + arc4->j = (arc4->j + arc4->sbox[n] + key[n]) % 256; + arc4_swap(&arc4->sbox[n], &arc4->sbox[arc4->j]); } - arc4_i = arc4_j = 0; + arc4->i = arc4->j = 0; /* Reset for next reseed cycle. */ - arc4_t_reseed = tv_now.tv_sec + ARC4_RESEED_SECONDS; - arc4_numruns = 0; + arc4->t_reseed = tv_now.tv_sec + ARC4_RESEED_SECONDS; + arc4->numruns = 0; /* * Throw away the first N words of output, as suggested in the * paper "Weaknesses in the Key Scheduling Algorithm of RC4" @@ -77,8 +89,9 @@ arc4_randomstir(void) * http://dl.acm.org/citation.cfm?id=646557.694759 */ for (n = 0; n < 768*4; n++) - arc4_randbyte(); - mtx_unlock(&arc4_mtx); + arc4_randbyte(arc4); + + mtx_unlock(&arc4->mtx); } /* @@ -87,33 +100,57 @@ arc4_randomstir(void) static void arc4_init(void) { + struct arc4_s *arc4; int n; - mtx_init(&arc4_mtx, "arc4_mtx", NULL, MTX_DEF); - arc4_i = arc4_j = 0; - for (n = 0; n < 256; n++) - arc4_sbox[n] = (u_int8_t) n; + arc4inst = malloc((mp_maxid + 1) * sizeof(struct arc4_s), + M_ARC4RANDOM, M_NOWAIT | M_ZERO); + KASSERT(arc4inst != NULL, ("arc4_init: memory allocation error")); + + ARC4_FOREACH(arc4) { + mtx_init(&arc4->mtx, "arc4_mtx", NULL, MTX_DEF); + + arc4->i = arc4->j = 0; + for (n = 0; n < 256; n++) + arc4->sbox[n] = (u_int8_t) n; + + arc4->t_reseed = -1; + arc4->numruns = 0; + } +} +SYSINIT(arc4, SI_SUB_LOCK, SI_ORDER_ANY, arc4_init, NULL); + + +static void +arc4_uninit(void) +{ + struct arc4_s *arc4; + + ARC4_FOREACH(arc4) { + mtx_destroy(&arc4->mtx); + } - arc4_t_reseed = 0; + free(arc4inst, M_ARC4RANDOM); } -SYSINIT(arc4_init, SI_SUB_LOCK, SI_ORDER_ANY, arc4_init, NULL); +SYSUNINIT(arc4, SI_SUB_LOCK, SI_ORDER_ANY, arc4_uninit, NULL); + /* * Generate a random byte. */ static u_int8_t -arc4_randbyte(void) +arc4_randbyte(struct arc4_s *arc4) { u_int8_t arc4_t; - arc4_i = (arc4_i + 1) % 256; - arc4_j = (arc4_j + arc4_sbox[arc4_i]) % 256; + arc4->i = (arc4->i + 1) % 256; + arc4->j = (arc4->j + arc4->sbox[arc4->i]) % 256; - arc4_swap(&arc4_sbox[arc4_i], &arc4_sbox[arc4_j]); + arc4_swap(&arc4->sbox[arc4->i], &arc4->sbox[arc4->j]); - arc4_t = (arc4_sbox[arc4_i] + arc4_sbox[arc4_j]) % 256; - return arc4_sbox[arc4_t]; + arc4_t = (arc4->sbox[arc4->i] + arc4->sbox[arc4->j]) % 256; + return arc4->sbox[arc4_t]; } /* @@ -124,20 +161,26 @@ arc4rand(void *ptr, u_int len, int reseed) { u_char *p; struct timeval tv; + struct arc4_s *arc4; + if (reseed || atomic_cmpset_int(&arc4rand_iniseed_state, + ARC4_ENTR_HAVE, ARC4_ENTR_SEED)) { + ARC4_FOREACH(arc4) + arc4_randomstir(arc4); + } + + arc4 = &arc4inst[curcpu]; getmicrouptime(&tv); - 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(); - - mtx_lock(&arc4_mtx); - arc4_numruns += len; + if ((arc4->numruns > ARC4_RESEED_BYTES) || + (tv.tv_sec > arc4->t_reseed)) + arc4_randomstir(arc4); + + mtx_lock(&arc4->mtx); + arc4->numruns += len; p = ptr; while (len--) - *p++ = arc4_randbyte(); - mtx_unlock(&arc4_mtx); + *p++ = arc4_randbyte(arc4); + mtx_unlock(&arc4->mtx); } uint32_t |
