<manifest:file-entry manifest:full-path="content.xml" manifest:media-type="text/xml" manifest:size="5451">
  <manifest:encryption-data manifest:checksum-type="urn:oasis:names:tc:opendocument:xmlns:manifest:1.0#sha256-1k" manifest:checksum="sf+SmkxOGrFYbK2wexrYQaML3M3JTKcQ/KsfS2eAmHQ=">
   <manifest:algorithm manifest:algorithm-name="http://www.w3.org/2001/04/xmlenc#aes256-cbc" manifest:initialisation-vector="b6PjQ7EG+uWyhk/z29dJJQ=="/>
   <manifest:start-key-generation manifest:start-key-generation-name="http://www.w3.org/2000/09/xmldsig#sha256" manifest:key-size="32"/>
   <manifest:key-derivation manifest:key-derivation-name="PBKDF2" manifest:key-size="32" manifest:iteration-count="100000" manifest:salt="tHaDznWSd1OYCyWzFGx1YA=="/>
  </manifest:encryption-data>
 </manifest:file-entry>

#!/usr/bin/perl

use strict;
use warnings;

use File::Slurp;
use Crypt::CBC;
use MIME::Base64;

my $xml_encr = read_file('content.xml');

my $iv = "b6PjQ7EG+uWyhk/z29dJJQ==";
$iv = decode_base64($iv);

my $salt = "tHaDznWSd1OYCyWzFGx1YA==";
$salt = decode_base64($salt);
#$salt = substr($salt,0,8);

my $cipher = Crypt::CBC->new(
    -pass => 'pwd123'
    , -cipher => 'Cipher::AES'
    , -keysize => 32
    , -chain_mode => 'cbc'
    , -pbkdf => 'pbkdf2'
    , -iter => 100000
    #, -hasher => 
    #, -header => 'salt'
    , -header => 'none'
    , -iv => $iv
    , -salt => $salt
    #, -padding =>
);

my $xml_decr = $cipher->decrypt($xml_encr);
print $xml_decr;