Mini Shell
#!/usr/local/bin/perl
#
# This is a partial implentation of the MD4 checksum code.
#
# NOTE
#
# The function &add() in this module is required as we need to be
# able to add 32bit integers ignoring overflow. The C code this is
# based on does this because it uses the underlying hardware to
# perform the required addition however we need to be more careful
# as Perl will overflow an int and produce a result of 0xffffffff
# which is not very useful. The &add() function splits its arguments
# into two shorts and adds these carrying overflow from the low short
# to the high short and ignoring carry from the high short. Not
# exactly efficient, but it works and is fast enough for the purposes
# of this implementation
#
package Authen::NTLM::MD4;
use vars qw($VERSION @ISA @EXPORT);
require Exporter;
$VERSION = "1.02";
@ISA = qw(Exporter);
@EXPORT = qw(mdfour);
my ($A, $B, $C, $D);
my (@X, $M);
sub mdfour
{
my ($in) = @_;
my ($i, $pos);
my $len = length($in);
my $b = $len * 8;
$in .= "\0"x128;
$A = 0x67452301;
$B = 0xefcdab89;
$C = 0x98badcfe;
$D = 0x10325476;
$pos = 0;
while ($len > 64)
{
©64(substr($in, $pos, 64));
&mdfour64;
$pos += 64;
$len -= 64;
}
my $buf = substr($in, $pos, $len);
$buf .= sprintf "%c", 0x80;
if ($len <= 55)
{
$buf .= "\0"x(55-$len);
$buf .= pack("V", $b);
$buf .= "\0"x4;
©64($buf);
&mdfour64;
}
else
{
$buf .= "\0"x(120-$len);
$buf .= pack("V", $b);
$buf .= "\0"x4;
©64(substr($buf, 0, 64));
&mdfour64;
©64(substr($buf, 64, 64));
&mdfour64;
}
my $out = pack("VVVV", $A, $B, $C, $D);
return $out;
}
sub F
{
my ($X, $Y, $Z) = @_;
my $res = ($X&$Y) | ((~$X)&$Z);
return $res;
}
sub G
{
my ($X, $Y, $Z) = @_;
return ($X&$Y) | ($X&$Z) | ($Y&$Z);
}
sub H
{
my ($X, $Y, $Z) = @_;
return $X^$Y^$Z;
}
sub lshift
{
my ($x, $s) = @_;
$x &= 0xffffffff;
return (($x<<$s)&0xffffffff) | ($x>>(32-$s));
}
sub ROUND1
{
my ($a, $b, $c, $d, $k, $s) = @_;
my $e = &add($a, &F($b, $c, $d), $X[$k]);
return &lshift($e, $s);
}
sub ROUND2
{
my ($a, $b, $c, $d, $k, $s) = @_;
my $e = &add($a, &G($b, $c, $d), $X[$k], 0x5a827999);
return &lshift($e, $s);
}
sub ROUND3
{
my ($a, $b, $c, $d, $k, $s) = @_;
my $e = &add($a, &H($b, $c, $d), $X[$k], 0x6ed9eba1);
return &lshift($e, $s);
}
sub mdfour64
{
my ($i, $AA, $BB, $CC, $DD);
@X = unpack("N16", $M);
$AA = $A;
$BB = $B;
$CC = $C;
$DD = $D;
$A = &ROUND1($A,$B,$C,$D, 0, 3); $D = &ROUND1($D,$A,$B,$C, 1, 7);
$C = &ROUND1($C,$D,$A,$B, 2,11); $B = &ROUND1($B,$C,$D,$A, 3,19);
$A = &ROUND1($A,$B,$C,$D, 4, 3); $D = &ROUND1($D,$A,$B,$C, 5, 7);
$C = &ROUND1($C,$D,$A,$B, 6,11); $B = &ROUND1($B,$C,$D,$A, 7,19);
$A = &ROUND1($A,$B,$C,$D, 8, 3); $D = &ROUND1($D,$A,$B,$C, 9, 7);
$C = &ROUND1($C,$D,$A,$B,10,11); $B = &ROUND1($B,$C,$D,$A,11,19);
$A = &ROUND1($A,$B,$C,$D,12, 3); $D = &ROUND1($D,$A,$B,$C,13, 7);
$C = &ROUND1($C,$D,$A,$B,14,11); $B = &ROUND1($B,$C,$D,$A,15,19);
$A = &ROUND2($A,$B,$C,$D, 0, 3); $D = &ROUND2($D,$A,$B,$C, 4, 5);
$C = &ROUND2($C,$D,$A,$B, 8, 9); $B = &ROUND2($B,$C,$D,$A,12,13);
$A = &ROUND2($A,$B,$C,$D, 1, 3); $D = &ROUND2($D,$A,$B,$C, 5, 5);
$C = &ROUND2($C,$D,$A,$B, 9, 9); $B = &ROUND2($B,$C,$D,$A,13,13);
$A = &ROUND2($A,$B,$C,$D, 2, 3); $D = &ROUND2($D,$A,$B,$C, 6, 5);
$C = &ROUND2($C,$D,$A,$B,10, 9); $B = &ROUND2($B,$C,$D,$A,14,13);
$A = &ROUND2($A,$B,$C,$D, 3, 3); $D = &ROUND2($D,$A,$B,$C, 7, 5);
$C = &ROUND2($C,$D,$A,$B,11, 9); $B = &ROUND2($B,$C,$D,$A,15,13);
$A = &ROUND3($A,$B,$C,$D, 0, 3); $D = &ROUND3($D,$A,$B,$C, 8, 9);
$C = &ROUND3($C,$D,$A,$B, 4,11); $B = &ROUND3($B,$C,$D,$A,12,15);
$A = &ROUND3($A,$B,$C,$D, 2, 3); $D = &ROUND3($D,$A,$B,$C,10, 9);
$C = &ROUND3($C,$D,$A,$B, 6,11); $B = &ROUND3($B,$C,$D,$A,14,15);
$A = &ROUND3($A,$B,$C,$D, 1, 3); $D = &ROUND3($D,$A,$B,$C, 9, 9);
$C = &ROUND3($C,$D,$A,$B, 5,11); $B = &ROUND3($B,$C,$D,$A,13,15);
$A = &ROUND3($A,$B,$C,$D, 3, 3); $D = &ROUND3($D,$A,$B,$C,11, 9);
$C = &ROUND3($C,$D,$A,$B, 7,11); $B = &ROUND3($B,$C,$D,$A,15,15);
$A = &add($A, $AA); $B = &add($B, $BB);
$C = &add($C, $CC); $D = &add($D, $DD);
$A &= 0xffffffff; $B &= 0xffffffff;
$C &= 0xffffffff; $D &= 0xffffffff;
map {$_ = 0} @X;
}
sub copy64
{
my ($in) = @_;
$M = pack("V16", unpack("N16", $in));
}
# see note at top of this file about this function
sub add
{
my (@nums) = @_;
my ($r_low, $r_high, $n_low, $l_high);
my $num;
$r_low = $r_high = 0;
foreach $num (@nums)
{
$n_low = $num & 0xffff;
$n_high = ($num&0xffff0000)>>16;
$r_low += $n_low;
($r_low&0xf0000) && $r_high++;
$r_low &= 0xffff;
$r_high += $n_high;
$r_high &= 0xffff;
}
return ($r_high<<16)|$r_low;
}
1;
Zerion Mini Shell 1.0