包含"^“的Perl XOR转义字符串

Question

在Perl中执行逐位XOR时，如何转义"^“字符？我的脚本是好的，但是当我输入一个像.1M80P]/)S@*>RQF^RM< \n这样的字符串时，输出就会变得混乱：

#!/usr/bin/perl

$key = pack("H*","3cb37efae7f4f376ebbd76cd");

print "Enter string to decode: ";
$str=<STDIN>;chomp $str; $str =~s/\\(.)/$1/g;
$dec = decode($str);
print "Decoded string value: $dec\n";

sub decode{
    @subvar=@_;
    my $sqlstr = $subvar[0];
    $cipher = unpack("u", $sqlstr);
    $plain = $cipher^$key;
    return substr($plain, 0, length($cipher));
}

输出：

Enter string to decode: .1M80P]/)S@*>RQF^RM< \n
Decoded string value: zen94==tuvosÊ×

奇怪的是，下面的字符串,\=_\\^M;+ D1F$U@7L\n可以正常工作，并解码为KL@OU4books!，但.;H ^F8B8EQ">SA^BDL8 \n没有像预期的那样工作，并返回了R3@coldfusioÆ

以下是ikegami清理后的代码(结果相同)：

#!/usr/bin/perl
use strict;
use warnings;

sub deliteral {
   my ($s) = @_;
   $s =~ s/\\n/\n/g;
   die "Unrecognised escape \\$1\n" if $s =~ /\\[a-zA-Z0-9]/;
   $s =~ s/\\(.)/$1/sg;
   return $s;   
}

sub uudecode {
   return unpack 'u', $_[0];
}

sub decode {
   my ($key, $cipher) = @_;
   return substr($cipher^$key, 0, length($cipher)); # XXX
}

my $key = pack('H*', '3cb37efae7f4f376ebbd76cd');

print "Enter string to decode: ";
chomp( my $coded = <STDIN> );

my $cipher = uudecode(deliteral($coded));
my $plain = decode($key, $cipher);
print("Plain text: $plain\n");

Answer 1

多亏了ikegami的帮助，这就是解决方案：

#!/usr/bin/perl
use strict;
use warnings;

sub deliteral {
   my ($s) = @_;
   $s =~ s/\\n/\n/g;
   die "Unrecognised escape \\$1\n" if $s =~ /(?<!\\)(?:\\{2})*\\([a-zA-Z0-9])/;   $s =~ s/\\(.)/$1/sg;
   return $s;   
}

sub uudecode {
   return unpack 'u', $_[0];
}

sub decode {
   my ($key, $cipher) = @_;
   return substr($cipher^$key, 0, length($cipher)); # XXX
}

my $key = pack('H*', '3cb37efae7f4f376ebbd76cdfce7391e9ed9cee4cfceb4b33332fc96ff7b');

print "Enter string to decode: ";
chomp( my $coded = <STDIN> );

my $cipher = uudecode(deliteral($coded));
my $plain = decode($key, $cipher);
print("Plain text: $plain\n");

问题出在密钥的长度上。