Use /dev/urandom, as it doesn't block, which /dev/random might do. Do not

1999-07-23  Sebastian Wilhelmi  <wilhelmi@ira.uka.de>

	* grand.c (g_rand_new): Use /dev/urandom, as it doesn't block,
	which /dev/random might do. Do not XOR the time, when getting the
	seed form /dev/urandom, as this is good itself. Prevent the
	initial seed from being zero, which causes the PRNG to produce
	only zeros. Hints from Colin Plumb <colin@pgp.com>.
This commit is contained in:
Sebastian Wilhelmi 1999-08-19 08:32:03 +00:00 committed by Sebastian Wilhelmi
parent 80c44ef391
commit e435032d6e
10 changed files with 100 additions and 32 deletions

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@ -1,3 +1,11 @@
1999-07-23 Sebastian Wilhelmi <wilhelmi@ira.uka.de>
* grand.c (g_rand_new): Use /dev/urandom, as it doesn't block,
which /dev/random might do. Do not XOR the time, when getting the
seed form /dev/urandom, as this is good itself. Prevent the
initial seed from being zero, which causes the PRNG to produce
only zeros. Hints from Colin Plumb <colin@pgp.com>.
1999-08-17 Tor Lillqvist <tml@iki.fi>
* glib.h (g_trash_stack_push): Add a cast.

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@ -1,3 +1,11 @@
1999-07-23 Sebastian Wilhelmi <wilhelmi@ira.uka.de>
* grand.c (g_rand_new): Use /dev/urandom, as it doesn't block,
which /dev/random might do. Do not XOR the time, when getting the
seed form /dev/urandom, as this is good itself. Prevent the
initial seed from being zero, which causes the PRNG to produce
only zeros. Hints from Colin Plumb <colin@pgp.com>.
1999-08-17 Tor Lillqvist <tml@iki.fi>
* glib.h (g_trash_stack_push): Add a cast.

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@ -1,3 +1,11 @@
1999-07-23 Sebastian Wilhelmi <wilhelmi@ira.uka.de>
* grand.c (g_rand_new): Use /dev/urandom, as it doesn't block,
which /dev/random might do. Do not XOR the time, when getting the
seed form /dev/urandom, as this is good itself. Prevent the
initial seed from being zero, which causes the PRNG to produce
only zeros. Hints from Colin Plumb <colin@pgp.com>.
1999-08-17 Tor Lillqvist <tml@iki.fi>
* glib.h (g_trash_stack_push): Add a cast.

View File

@ -1,3 +1,11 @@
1999-07-23 Sebastian Wilhelmi <wilhelmi@ira.uka.de>
* grand.c (g_rand_new): Use /dev/urandom, as it doesn't block,
which /dev/random might do. Do not XOR the time, when getting the
seed form /dev/urandom, as this is good itself. Prevent the
initial seed from being zero, which causes the PRNG to produce
only zeros. Hints from Colin Plumb <colin@pgp.com>.
1999-08-17 Tor Lillqvist <tml@iki.fi>
* glib.h (g_trash_stack_push): Add a cast.

View File

@ -1,3 +1,11 @@
1999-07-23 Sebastian Wilhelmi <wilhelmi@ira.uka.de>
* grand.c (g_rand_new): Use /dev/urandom, as it doesn't block,
which /dev/random might do. Do not XOR the time, when getting the
seed form /dev/urandom, as this is good itself. Prevent the
initial seed from being zero, which causes the PRNG to produce
only zeros. Hints from Colin Plumb <colin@pgp.com>.
1999-08-17 Tor Lillqvist <tml@iki.fi>
* glib.h (g_trash_stack_push): Add a cast.

View File

@ -1,3 +1,11 @@
1999-07-23 Sebastian Wilhelmi <wilhelmi@ira.uka.de>
* grand.c (g_rand_new): Use /dev/urandom, as it doesn't block,
which /dev/random might do. Do not XOR the time, when getting the
seed form /dev/urandom, as this is good itself. Prevent the
initial seed from being zero, which causes the PRNG to produce
only zeros. Hints from Colin Plumb <colin@pgp.com>.
1999-08-17 Tor Lillqvist <tml@iki.fi>
* glib.h (g_trash_stack_push): Add a cast.

View File

@ -1,3 +1,11 @@
1999-07-23 Sebastian Wilhelmi <wilhelmi@ira.uka.de>
* grand.c (g_rand_new): Use /dev/urandom, as it doesn't block,
which /dev/random might do. Do not XOR the time, when getting the
seed form /dev/urandom, as this is good itself. Prevent the
initial seed from being zero, which causes the PRNG to produce
only zeros. Hints from Colin Plumb <colin@pgp.com>.
1999-08-17 Tor Lillqvist <tml@iki.fi>
* glib.h (g_trash_stack_push): Add a cast.

View File

@ -1,3 +1,11 @@
1999-07-23 Sebastian Wilhelmi <wilhelmi@ira.uka.de>
* grand.c (g_rand_new): Use /dev/urandom, as it doesn't block,
which /dev/random might do. Do not XOR the time, when getting the
seed form /dev/urandom, as this is good itself. Prevent the
initial seed from being zero, which causes the PRNG to produce
only zeros. Hints from Colin Plumb <colin@pgp.com>.
1999-08-17 Tor Lillqvist <tml@iki.fi>
* glib.h (g_trash_stack_push): Add a cast.

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@ -75,31 +75,29 @@ g_rand_new_with_seed (guint32 seed)
GRand*
g_rand_new (void)
{
guint32 seed = 0;
guint32 seed;
GTimeVal now;
static gboolean dev_random_exists = TRUE;
static gboolean dev_urandom_exists = TRUE;
if (dev_random_exists)
if (dev_urandom_exists)
{
FILE* dev_random = fopen("/dev/random", "rb");
if (dev_random)
FILE* dev_urandom = fopen("/dev/urandom", "rb");
if (dev_urandom)
{
if (fread (&seed, sizeof (seed), 1, dev_random) != 1)
if (fread (&seed, sizeof (seed), 1, dev_urandom) != 1)
seed = 0;
else
dev_random_exists = FALSE;
fclose (dev_random);
dev_urandom_exists = FALSE;
fclose (dev_urandom);
}
else
dev_random_exists = FALSE;
dev_urandom_exists = FALSE;
}
/* Using /dev/random alone makes the seed computable for the
outside. This might pose security problems somewhere. This should
yield better values */
if (!dev_urandom_exists)
{
g_get_current_time (&now);
seed ^= now.tv_sec ^ now.tv_usec;
seed = now.tv_sec ^ now.tv_usec;
}
return g_rand_new_with_seed (seed);
}
@ -121,6 +119,10 @@ g_rand_set_seed (GRand* rand, guint32 seed)
/* the generator Line 25 of Table 1 in */
/* [KNUTH 1981, The Art of Computer Programming */
/* Vol. 2 (2nd Ed.), pp102] */
if (seed == 0) /* This would make the PRNG procude only zeros */
seed = 0x6b842128; /* Just set it to another number */
rand->mt[0]= seed & 0xffffffff;
for (rand->mti=1; rand->mti<N; rand->mti++)
rand->mt[rand->mti] = (69069 * rand->mt[rand->mti-1]) & 0xffffffff;

32
grand.c
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@ -75,31 +75,29 @@ g_rand_new_with_seed (guint32 seed)
GRand*
g_rand_new (void)
{
guint32 seed = 0;
guint32 seed;
GTimeVal now;
static gboolean dev_random_exists = TRUE;
static gboolean dev_urandom_exists = TRUE;
if (dev_random_exists)
if (dev_urandom_exists)
{
FILE* dev_random = fopen("/dev/random", "rb");
if (dev_random)
FILE* dev_urandom = fopen("/dev/urandom", "rb");
if (dev_urandom)
{
if (fread (&seed, sizeof (seed), 1, dev_random) != 1)
if (fread (&seed, sizeof (seed), 1, dev_urandom) != 1)
seed = 0;
else
dev_random_exists = FALSE;
fclose (dev_random);
dev_urandom_exists = FALSE;
fclose (dev_urandom);
}
else
dev_random_exists = FALSE;
dev_urandom_exists = FALSE;
}
/* Using /dev/random alone makes the seed computable for the
outside. This might pose security problems somewhere. This should
yield better values */
if (!dev_urandom_exists)
{
g_get_current_time (&now);
seed ^= now.tv_sec ^ now.tv_usec;
seed = now.tv_sec ^ now.tv_usec;
}
return g_rand_new_with_seed (seed);
}
@ -121,6 +119,10 @@ g_rand_set_seed (GRand* rand, guint32 seed)
/* the generator Line 25 of Table 1 in */
/* [KNUTH 1981, The Art of Computer Programming */
/* Vol. 2 (2nd Ed.), pp102] */
if (seed == 0) /* This would make the PRNG procude only zeros */
seed = 0x6b842128; /* Just set it to another number */
rand->mt[0]= seed & 0xffffffff;
for (rand->mti=1; rand->mti<N; rand->mti++)
rand->mt[rand->mti] = (69069 * rand->mt[rand->mti-1]) & 0xffffffff;