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Introduce .Lb macro to libcrypt manpage.

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Make it more mdoc(7) compliant:
. use .Tn for DES, MD5 andSHS.
. Replace double quotes with .Dq macro
. use An/Aq scheme for listing authors
This commit is contained in:
phantom 2000-04-22 15:56:59 +00:00
parent bb4bbaae0d
commit a19291893f
1 changed files with 54 additions and 19 deletions
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73
lib/libcrypt/crypt.3
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@ -37,6 +37,8 @@
.Sh NAME
.Nm crypt
.Nd Trapdoor encryption
.Sh LIBRARY
.Lb libcrypt
.Sh SYNOPSIS
.Fd #include <unistd.h>
.Ft char *
@ -54,12 +56,17 @@ in the hash.
.\"
Currently these include the
.Tn NBS
Data Encryption Standard (DES), MD5 or SHS. The algorithm
used will depend upon the format of the Salt--following the Modular
Crypt Format (MCF)--and if DES is installed or not.
.Tn Data Encryption Standard (DES) ,
.Tn MD5
or
.Tn SHS .
The algorithm used will depend upon the format of the Salt--following
the Modular Crypt Format (MCF)--and if
.Tn DES
is installed or not.
.Pp
The first argument to
.Nm crypt
.Nm
is the data to hash (usually a password), in a
.Dv null Ns -terminated
string.
@ -67,18 +74,26 @@ The second is the salt, in one of three forms:
.Pp
.Bl -tag -width Traditional -compact -offset indent
.It Extended
If it begins with an underscore (``_'') then the DES Extended Format
If it begins with an underscore
.Pq Dq _
then the
.Tn DES
Extended Format
is used in interpreting both the the key and the salt, as outlined below.
.It Modular
If it begins with the string ``$digit$'' then the Modular Crypt Format
is used, as outlined below.
If it begins with the string
.Dq $digit$
then the Modular Crypt Format is used, as outlined below.
.It Traditional
If neither of the above is true, it assumes the Traditional Format,
using the entire string as the salt (or the first portion).
.El
.Pp
All routines are designed to be time-consuming. A brief test on a
Pentium 166/MMX shows the DES crypt to do approximately 2640 crypts
.Tn Pentium
166/MMX shows the
.Tn DES
crypt to do approximately 2640 crypts
a CPU second and MD5 to do about 62 crypts a CPU second.
.Ss DES Extended Format:
.Pp
@ -86,10 +101,17 @@ The
.Ar key
is divided into groups of 8 characters (the last group is null-padded)
and the low-order 7 bits of each each character (56 bits per group) are
used to form the DES key as follows:
the first group of 56 bits becomes the initial DES key.
For each additional group, the XOR of the encryption of the current DES
key with itself and the group bits becomes the next DES key.
used to form the
.Tn DES
key as follows:
the first group of 56 bits becomes the initial
.Tn DES
key.
For each additional group, the XOR of the encryption of the current
.Tn DES
key with itself and the group bits becomes the next
.Tn DES
key.
.Pp
The salt is a 9-character array consisting of an underscore followed
by 4 bytes of iteration count and 4 bytes of salt.
@ -118,7 +140,9 @@ are swapped in the
.Tn DES
E-box output).
.Pp
The DES key is used to encrypt a 64-bit constant using
The
.Tn DES
key is used to encrypt a 64-bit constant using
.Ar count
iterations of
.Tn DES .
@ -153,8 +177,11 @@ Other crypt formats may be easilly added. An example salt would be:
.Pp
.Ss "Traditional" crypt:
.Pp
The algorithm used will depend upon whether DES is installed or not. If it is,
DES will be used. Otherwise, the best algorithm is used, which is currently
The algorithm used will depend upon whether
.Tn DES
is installed or not. If it is,
.Tn DES
will be used. Otherwise, the best algorithm is used, which is currently
.\"
.\" NOTICE: Also make sure to update this
.\"
@ -191,11 +218,19 @@ The current style
first appeared in
.At v7 .
.Pp
The DES section of the code (FreeSec 1.0) was developed outside the United
States of America as an unencumbered replacement for the U.S.-only NetBSD
The
.Tn DES
section of the code (FreeSec 1.0) was developed outside the United
States of America as an unencumbered replacement for the U.S.-only
.Nx
libcrypt encryption library.
Users should be aware that this code (and programs staticly linked with it)
may not be exported from the U.S., although it apparently can be imported.
.Sh AUTHORS
Originally written by David Burren <davidb@werj.com.au>, later additions
and changes by Poul-henning Kamp, Mark R V Murray and Kris Kennaway.
Originally written by
.An David Burren Aq davidb@werj.com.au ,
later additions and changes by
.An Poul-henning Kamp ,
.An Mark R V Murray
and
.An Kris Kennaway .