TH RC4 2
SH NAME
setupRC4state, rc4, rc4skip, rc4back - alleged rc4 encryption
SH SYNOPSIS
B #include <u.h>
br
B #include <libc.h>
br
B #include <mp.h>
br
B #include <libsec.h>
PP
B
void setupRC4state(RC4state *s, uchar *seed, int slen)
PP
B
void rc4(RC4state *s, uchar *data, int dlen)
PP
B
void rc4skip(RC4state *s, int nbytes)
PP
B
void rc4back(RC4state *s, int nbytes)
SH DESCRIPTION
PP
This is an algorithm alleged to be Rivest's RC4 encryption function. It is
a pseudo-random number generator with a 256 byte state and a long
cycle. The input buffer is XOR'd with the output of the
generator both to encrypt and to decrypt. The seed, entered
using
IR setupRC4state ,
can be any length. The generator can be run forward using
IR rc4 ,
skip over bytes using
I rc4skip
to account lost transmissions,
or run backwards using
I rc4back
to cover retransmitted data.
The
I RC4state
structure keeps track of the algorithm.
SH SOURCE
B /sys/src/libsec
SH SEE ALSO
IR mp (2),
IR aes (2),
IR blowfish (2),
IR des (2),
IR dsa (2),
IR elgamal (2),
IR rsa (2),
IR sechash (2),
IR prime (2),
IR rand (2)
