diff --git a/src/lib/libc/crypt/arc4random.c b/src/lib/libc/crypt/arc4random.c index 7a2d9e80..03eb047f 100644 --- a/src/lib/libc/crypt/arc4random.c +++ b/src/lib/libc/crypt/arc4random.c @@ -1,4 +1,4 @@ -/* $OpenBSD: arc4random.c,v 1.33 2014/06/13 18:58:58 deraadt Exp $ */ +/* $OpenBSD: arc4random.c,v 1.34 2014/06/17 00:37:07 matthew Exp $ */ /* * Copyright (c) 1996, David Mazieres @@ -48,12 +48,13 @@ #define IVSZ 8 #define BLOCKSZ 64 #define RSBUFSZ (16*BLOCKSZ) -static int rs_initialized; -static pid_t rs_stir_pid; -static chacha_ctx *rs; /* chacha context for random keystream */ + +static struct { + size_t rs_have; /* valid bytes at end of rs_buf */ + size_t rs_count; /* bytes till reseed */ + chacha_ctx rs_chacha; /* chacha context for random keystream */ +} *rs; static u_char *rs_buf; /* keystream blocks */ -static size_t rs_have; /* valid bytes at end of rs_buf */ -static size_t rs_count; /* bytes till reseed */ static inline void _rs_rekey(u_char *dat, size_t datlen); @@ -63,15 +64,23 @@ _rs_init(u_char *buf, size_t n) if (n < KEYSZ + IVSZ) return; - if (rs == NULL && (rs = mmap(NULL, sizeof(*rs), PROT_READ|PROT_WRITE, - MAP_ANON, -1, 0)) == MAP_FAILED) - abort(); - if (rs_buf == NULL && (rs_buf = mmap(NULL, RSBUFSZ, PROT_READ|PROT_WRITE, - MAP_ANON, -1, 0)) == MAP_FAILED) - abort(); + if (rs == NULL) { + if ((rs = mmap(NULL, sizeof(*rs), PROT_READ|PROT_WRITE, + MAP_ANON, -1, 0)) == MAP_FAILED) + abort(); + if (minherit(rs, sizeof(*rs), MAP_INHERIT_ZERO) == -1) + abort(); + } + if (rs_buf == NULL) { + if ((rs_buf = mmap(NULL, RSBUFSZ, PROT_READ|PROT_WRITE, + MAP_ANON, -1, 0)) == MAP_FAILED) + abort(); + if (minherit(rs_buf, RSBUFSZ, MAP_INHERIT_ZERO) == -1) + abort(); + } - chacha_keysetup(rs, buf, KEYSZ * 8, 0); - chacha_ivsetup(rs, buf + KEYSZ); + chacha_keysetup(&rs->rs_chacha, buf, KEYSZ * 8, 0); + chacha_ivsetup(&rs->rs_chacha, buf + KEYSZ); } static void @@ -82,30 +91,28 @@ _rs_stir(void) /* XXX */ (void) getentropy(rnd, sizeof rnd); - if (!rs_initialized) { - rs_initialized = 1; + if (!rs) _rs_init(rnd, sizeof(rnd)); - } else + else _rs_rekey(rnd, sizeof(rnd)); explicit_bzero(rnd, sizeof(rnd)); /* invalidate rs_buf */ - rs_have = 0; + rs->rs_have = 0; memset(rs_buf, 0, RSBUFSZ); - rs_count = 1600000; + rs->rs_count = 1600000; } static inline void _rs_stir_if_needed(size_t len) { - pid_t pid = getpid(); - - if (rs_count <= len || !rs_initialized || rs_stir_pid != pid) { - rs_stir_pid = pid; + if (!rs || rs->rs_count <= len) _rs_stir(); - } else - rs_count -= len; + if (rs->rs_count <= len) + rs->rs_count = 0; + else + rs->rs_count -= len; } static inline void @@ -115,7 +122,7 @@ _rs_rekey(u_char *dat, size_t datlen) memset(rs_buf, 0,RSBUFSZ); #endif /* fill rs_buf with the keystream */ - chacha_encrypt_bytes(rs, rs_buf, rs_buf, RSBUFSZ); + chacha_encrypt_bytes(&rs->rs_chacha, rs_buf, rs_buf, RSBUFSZ); /* mix in optional user provided data */ if (dat) { size_t i, m; @@ -127,7 +134,7 @@ _rs_rekey(u_char *dat, size_t datlen) /* immediately reinit for backtracking resistance */ _rs_init(rs_buf, KEYSZ + IVSZ); memset(rs_buf, 0, KEYSZ + IVSZ); - rs_have = RSBUFSZ - KEYSZ - IVSZ; + rs->rs_have = RSBUFSZ - KEYSZ - IVSZ; } static inline void @@ -138,15 +145,15 @@ _rs_random_buf(void *_buf, size_t n) _rs_stir_if_needed(n); while (n > 0) { - if (rs_have > 0) { - m = MIN(n, rs_have); - memcpy(buf, rs_buf + RSBUFSZ - rs_have, m); - memset(rs_buf + RSBUFSZ - rs_have, 0, m); + if (rs->rs_have > 0) { + m = MIN(n, rs->rs_have); + memcpy(buf, rs_buf + RSBUFSZ - rs->rs_have, m); + memset(rs_buf + RSBUFSZ - rs->rs_have, 0, m); buf += m; n -= m; - rs_have -= m; + rs->rs_have -= m; } - if (rs_have == 0) + if (rs->rs_have == 0) _rs_rekey(NULL, 0); } } @@ -155,11 +162,11 @@ static inline void _rs_random_u32(u_int32_t *val) { _rs_stir_if_needed(sizeof(*val)); - if (rs_have < sizeof(*val)) + if (rs->rs_have < sizeof(*val)) _rs_rekey(NULL, 0); - memcpy(val, rs_buf + RSBUFSZ - rs_have, sizeof(*val)); - memset(rs_buf + RSBUFSZ - rs_have, 0, sizeof(*val)); - rs_have -= sizeof(*val); + memcpy(val, rs_buf + RSBUFSZ - rs->rs_have, sizeof(*val)); + memset(rs_buf + RSBUFSZ - rs->rs_have, 0, sizeof(*val)); + rs->rs_have -= sizeof(*val); } u_int32_t