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