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| author | guenther <> | 2009-12-15 18:19:06 +0000 |
|---|---|---|
| committer | guenther <> | 2009-12-15 18:19:06 +0000 |
| commit | 0ac52e6e4d02749d85405ea08400d4b7e6db2ca1 (patch) | |
| tree | 4f708f2e07feb88d20f5fc86fd6a5b8aaaa620f7 | |
| parent | e0fd73fcca39e03d57dc0a553e943e84cda61e30 (diff) | |
| download | openbsd-0ac52e6e4d02749d85405ea08400d4b7e6db2ca1.tar.gz openbsd-0ac52e6e4d02749d85405ea08400d4b7e6db2ca1.tar.bz2 openbsd-0ac52e6e4d02749d85405ea08400d4b7e6db2ca1.zip | |
No point in refreshing the pid from inside arc4_stir() when that
doesn't test it, so factor out the two places that test it into a
routine and do the refreshing there. With this, arch4random_buf()
doesn't trigger superfluous calls to getpid() when filling large
buffers.
ok deraadt@, "looks nicer indeed" otto@
| -rw-r--r-- | src/lib/libc/crypt/arc4random.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/src/lib/libc/crypt/arc4random.c b/src/lib/libc/crypt/arc4random.c index e921e4b7c7..7580e39fb5 100644 --- a/src/lib/libc/crypt/arc4random.c +++ b/src/lib/libc/crypt/arc4random.c | |||
| @@ -1,4 +1,4 @@ | |||
| 1 | /* $OpenBSD: arc4random.c,v 1.20 2008/10/03 18:46:04 otto Exp $ */ | 1 | /* $OpenBSD: arc4random.c,v 1.21 2009/12/15 18:19:06 guenther Exp $ */ |
| 2 | 2 | ||
| 3 | /* | 3 | /* |
| 4 | * Copyright (c) 1996, David Mazieres <dm@uun.org> | 4 | * Copyright (c) 1996, David Mazieres <dm@uun.org> |
| @@ -109,7 +109,6 @@ arc4_stir(void) | |||
| 109 | len = sizeof(rnd); | 109 | len = sizeof(rnd); |
| 110 | sysctl(mib, 2, rnd, &len, NULL, 0); | 110 | sysctl(mib, 2, rnd, &len, NULL, 0); |
| 111 | 111 | ||
| 112 | arc4_stir_pid = getpid(); | ||
| 113 | arc4_addrandom(rnd, sizeof(rnd)); | 112 | arc4_addrandom(rnd, sizeof(rnd)); |
| 114 | 113 | ||
| 115 | /* | 114 | /* |
| @@ -121,6 +120,18 @@ arc4_stir(void) | |||
| 121 | arc4_count = 1600000; | 120 | arc4_count = 1600000; |
| 122 | } | 121 | } |
| 123 | 122 | ||
| 123 | static void | ||
| 124 | arc4_stir_if_needed(void) | ||
| 125 | { | ||
| 126 | pid_t pid = getpid(); | ||
| 127 | |||
| 128 | if (arc4_count <= 0 || !rs_initialized || arc4_stir_pid != pid) | ||
| 129 | { | ||
| 130 | arc4_stir_pid = pid; | ||
| 131 | arc4_stir(); | ||
| 132 | } | ||
| 133 | } | ||
| 134 | |||
| 124 | static inline u_int8_t | 135 | static inline u_int8_t |
| 125 | arc4_getbyte(void) | 136 | arc4_getbyte(void) |
| 126 | { | 137 | { |
| @@ -170,8 +181,7 @@ arc4random(void) | |||
| 170 | u_int32_t val; | 181 | u_int32_t val; |
| 171 | _ARC4_LOCK(); | 182 | _ARC4_LOCK(); |
| 172 | arc4_count -= 4; | 183 | arc4_count -= 4; |
| 173 | if (arc4_count <= 0 || !rs_initialized || arc4_stir_pid != getpid()) | 184 | arc4_stir_if_needed(); |
| 174 | arc4_stir(); | ||
| 175 | val = arc4_getword(); | 185 | val = arc4_getword(); |
| 176 | _ARC4_UNLOCK(); | 186 | _ARC4_UNLOCK(); |
| 177 | return val; | 187 | return val; |
| @@ -182,8 +192,7 @@ arc4random_buf(void *_buf, size_t n) | |||
| 182 | { | 192 | { |
| 183 | u_char *buf = (u_char *)_buf; | 193 | u_char *buf = (u_char *)_buf; |
| 184 | _ARC4_LOCK(); | 194 | _ARC4_LOCK(); |
| 185 | if (!rs_initialized || arc4_stir_pid != getpid()) | 195 | arc4_stir_if_needed(); |
| 186 | arc4_stir(); | ||
| 187 | while (n--) { | 196 | while (n--) { |
| 188 | if (--arc4_count <= 0) | 197 | if (--arc4_count <= 0) |
| 189 | arc4_stir(); | 198 | arc4_stir(); |