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authorDamien Miller <djm@cvs.openbsd.org>2012-01-05 23:01:40 +0000
committerDamien Miller <djm@cvs.openbsd.org>2012-01-05 23:01:40 +0000
commita92139156a50b00800436436ed28ad6ac0baa54b (patch)
treee2fbe38500bbd892d64b5cd2b0be5100fcc6dae0 /lib/libcrypto/rand/rand_unix.c
parent37f42acd42691d60502b271f1f0c823dcd37f59f (diff)
OpenSSL 1.0.0f: merge
Diffstat (limited to 'lib/libcrypto/rand/rand_unix.c')
-rw-r--r--lib/libcrypto/rand/rand_unix.c108
1 files changed, 74 insertions, 34 deletions
diff --git a/lib/libcrypto/rand/rand_unix.c b/lib/libcrypto/rand/rand_unix.c
index 4bb9666e49d..3316388443e 100644
--- a/lib/libcrypto/rand/rand_unix.c
+++ b/lib/libcrypto/rand/rand_unix.c
@@ -133,47 +133,87 @@
# define FD_SETSIZE (8*sizeof(fd_set))
#endif
-#ifdef __VOS__
+#if defined(OPENSSL_SYS_VOS)
+
+/* The following algorithm repeatedly samples the real-time clock
+ (RTC) to generate a sequence of unpredictable data. The algorithm
+ relies upon the uneven execution speed of the code (due to factors
+ such as cache misses, interrupts, bus activity, and scheduling) and
+ upon the rather large relative difference between the speed of the
+ clock and the rate at which it can be read.
+
+ If this code is ported to an environment where execution speed is
+ more constant or where the RTC ticks at a much slower rate, or the
+ clock can be read with fewer instructions, it is likely that the
+ results would be far more predictable.
+
+ As a precaution, we generate 4 times the minimum required amount of
+ seed data. */
+
int RAND_poll(void)
{
- unsigned char buf[ENTROPY_NEEDED];
+ short int code;
+ gid_t curr_gid;
pid_t curr_pid;
uid_t curr_uid;
- static int first=1;
- int i;
- long rnd = 0;
+ int i, k;
struct timespec ts;
- unsigned seed;
-
-/* The VOS random() function starts from a static seed so its
- initial value is predictable. If random() returns the
- initial value, reseed it with dynamic data. The VOS
- real-time clock has a granularity of 1 nsec so it should be
- reasonably difficult to predict its exact value. Do not
- gratuitously reseed the PRNG because other code in this
- process or thread may be using it. */
-
- if (first) {
- first = 0;
- rnd = random ();
- if (rnd == 1804289383) {
- clock_gettime (CLOCK_REALTIME, &ts);
- curr_pid = getpid();
- curr_uid = getuid();
- seed = ts.tv_sec ^ ts.tv_nsec ^ curr_pid ^ curr_uid;
- srandom (seed);
- }
- }
+ unsigned char v;
- for (i = 0; i < sizeof(buf); i++) {
- if (i % 4 == 0)
- rnd = random();
- buf[i] = rnd;
- rnd >>= 8;
- }
- RAND_add(buf, sizeof(buf), ENTROPY_NEEDED);
- memset(buf, 0, sizeof(buf));
+#ifdef OPENSSL_SYS_VOS_HPPA
+ long duration;
+ extern void s$sleep (long *_duration, short int *_code);
+#else
+#ifdef OPENSSL_SYS_VOS_IA32
+ long long duration;
+ extern void s$sleep2 (long long *_duration, short int *_code);
+#else
+#error "Unsupported Platform."
+#endif /* OPENSSL_SYS_VOS_IA32 */
+#endif /* OPENSSL_SYS_VOS_HPPA */
+ /* Seed with the gid, pid, and uid, to ensure *some*
+ variation between different processes. */
+
+ curr_gid = getgid();
+ RAND_add (&curr_gid, sizeof curr_gid, 1);
+ curr_gid = 0;
+
+ curr_pid = getpid();
+ RAND_add (&curr_pid, sizeof curr_pid, 1);
+ curr_pid = 0;
+
+ curr_uid = getuid();
+ RAND_add (&curr_uid, sizeof curr_uid, 1);
+ curr_uid = 0;
+
+ for (i=0; i<(ENTROPY_NEEDED*4); i++)
+ {
+ /* burn some cpu; hope for interrupts, cache
+ collisions, bus interference, etc. */
+ for (k=0; k<99; k++)
+ ts.tv_nsec = random ();
+
+#ifdef OPENSSL_SYS_VOS_HPPA
+ /* sleep for 1/1024 of a second (976 us). */
+ duration = 1;
+ s$sleep (&duration, &code);
+#else
+#ifdef OPENSSL_SYS_VOS_IA32
+ /* sleep for 1/65536 of a second (15 us). */
+ duration = 1;
+ s$sleep2 (&duration, &code);
+#endif /* OPENSSL_SYS_VOS_IA32 */
+#endif /* OPENSSL_SYS_VOS_HPPA */
+
+ /* get wall clock time. */
+ clock_gettime (CLOCK_REALTIME, &ts);
+
+ /* take 8 bits */
+ v = (unsigned char) (ts.tv_nsec % 256);
+ RAND_add (&v, sizeof v, 1);
+ v = 0;
+ }
return 1;
}
#elif defined __OpenBSD__