.\" Grr, why do .Bl/.El produce a blank line before but not after?!
.\" It seems damn near impossible to get a blank line.
.\" .D1 and .Dl with no argument produce a whine.
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.de bL
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..
.Dd July 31, 2000
.Dt ARC4CRYPT 1
.Os NetBSD 1.2BETA
.Sh NAME
.Nm arc4crypt
.Nd ARC4-based encryption utility
.Sh SYNOPSIS
.Nm descrypt
.Op flags
.Op Ar keyphrase
.Sh DESCRIPTION
.Nm
performs encryption with the arcfour encryption algorithm using a key
derived from the specified
.Ar keyphrase .
Furthermore, certain
.Ar flags
can also be specified.
.Pp
The flags recognized are:
.Bl -tag -width indent
.It Fl binkey
Instead of taking the
.Ar keyphrase
argument as the key itself, it is taken as a sequence of hex numbers
which specify the bytes of the key.  Non-hex-digit characters are
ignored except insofar as they serve to delimit key bytes.
.It Fl textkey
The reverse of
.Fl binkey ;
that is, the
.Ar keyphrase
argument is taken as the key itself.
.It Fl readkey Ar fd
The key is read from the specified
.Ar fd
rather than being taken from the command line.
.Fl binkey
and
.Fl textkey
are ignored.  A
.Ar keyphrase
argument may still be present, but if present it is ignored.  This is
intended to improve security by not exposing key data to snooping with
.Xr ps 1
or related programs at all.
.Pf ( Nm arc4crypt
is careful to destroy key-related command-line arguments as soon as
possible, but there is still a window during which the information is
visible.)  When
.Ar fd
is 0, for standard input, standard input is read up to and including
the first newline; the newline is stripped and the rest is taken as key
data.  This is done before any data to be operated upon is read.  When
.Ar fd
is nonzero, the specified file descriptor is read to EOF.  Note that
there is risk of an incompatability between a key specified on the
command line, or on standard input, which will not include a trailing
newline, and a key specified on another fd, which is likely to include
a trailing newline.  A key with a trailing newline is as different from
a key without it as any other two distinct keys are.
.It Fl key Ar keyphrase
This is just like specifying the
.Ar keyphrase
on the command line with no flag, except it is unambiguous when
.Ar keyphrase
begins, or might begin, with a
.Sq \&\- .
.It Fl discard Ar N
Discard the first N bytes of keystream material after setting the key.
Using too low a value will impair security; values in the thousands, or
low tens of thousands, are recommended.  (This value can be considered
a part of the key, though a comparatively low-security part.)  If not
specified, the default is 32768.
.It Fl debug
Turn on debugging info.  This is likely to be extremely verbose and is
not documented here; see the source code for more information.
.El
.Pp
When conflicting arguments are given (such as
.Fl binkey
and
.Fl textkey ) ,
the one that appears last on the command line wins.
.Sh AUTHOR
der Mouse,
.Aq mouse@rodents.montreal.qc.ca .