diff options
Diffstat (limited to 'sys/dev/rnd.c')
| -rw-r--r-- | sys/dev/rnd.c | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/sys/dev/rnd.c b/sys/dev/rnd.c index d55cd8c8324..136d45a8f45 100644 --- a/sys/dev/rnd.c +++ b/sys/dev/rnd.c @@ -1,4 +1,4 @@ -/* $OpenBSD: rnd.c,v 1.8 1996/09/06 08:36:13 mickey Exp $ */ +/* $OpenBSD: rnd.c,v 1.9 1996/09/29 16:42:00 dm Exp $ */ /* * random.c -- A strong random number generator @@ -331,6 +331,24 @@ static int rnd_sleep = 0; #define MIN(a,b) (((a) < (b)) ? (a) : (b)) #endif +/* Arcfour random stream generator. This code is derived from section + * 17.1 of Applied Cryptography, second edition, which describes a + * stream cipher allegedly compatible with RSA Labs "RC4" cipher (the + * actual description of which is a trade secret). The same algorithm + * is used as a stream cipher called "arcfour" in Tatu Ylonen's ssh + * package. + * + * The initialization function here has been modified not to discard + * old state, and its input always includes the time of day in + * microseconds. Moreover, bytes from the stream may at any point be + * diverted to multiple processes or even kernel functions desiring + * random numbers. This increases the strenght of the random stream, + * but makes it impossible to use this code for encryption--There is + * no way ever to reproduce the same stream of random bytes. + * + * RC4 is a registered trademark of RSA Laboratories. + */ + static void arc4_init (struct arc4_stream *as, u_char *data, int len) { |