549 lines
22 KiB
PHP
549 lines
22 KiB
PHP
<?php
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/**
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* @copyright Copyright (c)2009-2013 Nicholas K. Dionysopoulos
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* @license GNU General Public License version 3, or later
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*
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* @since 2.4
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*/
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// Protection against direct access
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defined('JPATH_PLATFORM') or die();
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/**
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* AES implementation in PHP (c) Chris Veness 2005-2013.
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* Right to use and adapt is granted for under a simple creative commons attribution
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* licence. No warranty of any form is offered.
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*
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* Modified for Akeeba Backup by Nicholas K. Dionysopoulos
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* Included for JCE with the kind permission of Nicholas K. Dionysopoulos
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*/
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class WFUtilEncrypt
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{
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// Sbox is pre-computed multiplicative inverse in GF(2^8) used in SubBytes and KeyExpansion [<5B>5.1.1]
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protected static $Sbox =
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array(0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,
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0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
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0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
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0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
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0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,
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0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
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0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,
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0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
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0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
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0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
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0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,
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0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
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0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
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0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
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0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
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0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16, );
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// Rcon is Round Constant used for the Key Expansion [1st col is 2^(r-1) in GF(2^8)] [<5B>5.2]
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protected static $Rcon = array(
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array(0x00, 0x00, 0x00, 0x00),
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array(0x01, 0x00, 0x00, 0x00),
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array(0x02, 0x00, 0x00, 0x00),
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array(0x04, 0x00, 0x00, 0x00),
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array(0x08, 0x00, 0x00, 0x00),
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array(0x10, 0x00, 0x00, 0x00),
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array(0x20, 0x00, 0x00, 0x00),
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array(0x40, 0x00, 0x00, 0x00),
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array(0x80, 0x00, 0x00, 0x00),
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array(0x1b, 0x00, 0x00, 0x00),
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array(0x36, 0x00, 0x00, 0x00), );
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protected static $passwords = array();
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/**
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* AES Cipher function: encrypt 'input' with Rijndael algorithm.
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*
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* @param input message as byte-array (16 bytes)
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* @param w key schedule as 2D byte-array (Nr+1 x Nb bytes) -
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* generated from the cipher key by KeyExpansion()
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*
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* @return ciphertext as byte-array (16 bytes)
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*/
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public static function Cipher($input, $w)
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{ // main Cipher function [<5B>5.1]
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$Nb = 4; // block size (in words): no of columns in state (fixed at 4 for AES)
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$Nr = count($w) / $Nb - 1; // no of rounds: 10/12/14 for 128/192/256-bit keys
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$state = array(); // initialise 4xNb byte-array 'state' with input [<5B>3.4]
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for ($i = 0; $i < 4 * $Nb; ++$i) {
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$state[$i % 4][floor($i / 4)] = $input[$i];
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}
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$state = self::AddRoundKey($state, $w, 0, $Nb);
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for ($round = 1; $round < $Nr; ++$round) { // apply Nr rounds
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$state = self::SubBytes($state, $Nb);
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$state = self::ShiftRows($state, $Nb);
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$state = self::MixColumns($state, $Nb);
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$state = self::AddRoundKey($state, $w, $round, $Nb);
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}
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$state = self::SubBytes($state, $Nb);
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$state = self::ShiftRows($state, $Nb);
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$state = self::AddRoundKey($state, $w, $Nr, $Nb);
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$output = array(4 * $Nb); // convert state to 1-d array before returning [<5B>3.4]
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for ($i = 0; $i < 4 * $Nb; ++$i) {
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$output[$i] = $state[$i % 4][floor($i / 4)];
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}
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return $output;
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}
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protected static function AddRoundKey($state, $w, $rnd, $Nb)
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{ // xor Round Key into state S [<5B>5.1.4]
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for ($r = 0; $r < 4; ++$r) {
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for ($c = 0; $c < $Nb; ++$c) {
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$state[$r][$c] ^= $w[$rnd * 4 + $c][$r];
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}
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}
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return $state;
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}
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protected static function SubBytes($s, $Nb)
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{ // apply SBox to state S [<5B>5.1.1]
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for ($r = 0; $r < 4; ++$r) {
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for ($c = 0; $c < $Nb; ++$c) {
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$s[$r][$c] = self::$Sbox[$s[$r][$c]];
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}
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}
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return $s;
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}
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protected static function ShiftRows($s, $Nb)
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{ // shift row r of state S left by r bytes [<5B>5.1.2]
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$t = array(4);
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for ($r = 1; $r < 4; ++$r) {
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for ($c = 0; $c < 4; ++$c) {
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$t[$c] = $s[$r][($c + $r) % $Nb];
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} // shift into temp copy
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for ($c = 0; $c < 4; ++$c) {
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$s[$r][$c] = $t[$c];
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} // and copy back
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} // note that this will work for Nb=4,5,6, but not 7,8 (always 4 for AES):
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return $s; // see fp.gladman.plus.com/cryptography_technology/rijndael/aes.spec.311.pdf
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}
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protected static function MixColumns($s, $Nb)
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{ // combine bytes of each col of state S [<5B>5.1.3]
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for ($c = 0; $c < 4; ++$c) {
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$a = array(4); // 'a' is a copy of the current column from 's'
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$b = array(4); // 'b' is a<>{02} in GF(2^8)
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for ($i = 0; $i < 4; ++$i) {
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$a[$i] = $s[$i][$c];
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$b[$i] = $s[$i][$c] & 0x80 ? $s[$i][$c] << 1 ^ 0x011b : $s[$i][$c] << 1;
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}
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// a[n] ^ b[n] is a<>{03} in GF(2^8)
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$s[0][$c] = $b[0] ^ $a[1] ^ $b[1] ^ $a[2] ^ $a[3]; // 2*a0 + 3*a1 + a2 + a3
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$s[1][$c] = $a[0] ^ $b[1] ^ $a[2] ^ $b[2] ^ $a[3]; // a0 * 2*a1 + 3*a2 + a3
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$s[2][$c] = $a[0] ^ $a[1] ^ $b[2] ^ $a[3] ^ $b[3]; // a0 + a1 + 2*a2 + 3*a3
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$s[3][$c] = $a[0] ^ $b[0] ^ $a[1] ^ $a[2] ^ $b[3]; // 3*a0 + a1 + a2 + 2*a3
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}
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return $s;
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}
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/**
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* Key expansion for Rijndael Cipher(): performs key expansion on cipher key
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* to generate a key schedule.
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*
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* @param key cipher key byte-array (16 bytes)
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*
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* @return key schedule as 2D byte-array (Nr+1 x Nb bytes)
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*/
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public static function KeyExpansion($key)
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{ // generate Key Schedule from Cipher Key [<5B>5.2]
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$Nb = 4; // block size (in words): no of columns in state (fixed at 4 for AES)
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$Nk = count($key) / 4; // key length (in words): 4/6/8 for 128/192/256-bit keys
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$Nr = $Nk + 6; // no of rounds: 10/12/14 for 128/192/256-bit keys
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$w = array();
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$temp = array();
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for ($i = 0; $i < $Nk; ++$i) {
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$r = array($key[4 * $i], $key[4 * $i + 1], $key[4 * $i + 2], $key[4 * $i + 3]);
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$w[$i] = $r;
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}
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for ($i = $Nk; $i < ($Nb * ($Nr + 1)); ++$i) {
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$w[$i] = array();
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for ($t = 0; $t < 4; ++$t) {
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$temp[$t] = $w[$i - 1][$t];
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}
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if ($i % $Nk == 0) {
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$temp = self::SubWord(self::RotWord($temp));
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for ($t = 0; $t < 4; ++$t) {
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$temp[$t] ^= self::$Rcon[$i / $Nk][$t];
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}
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} elseif ($Nk > 6 && $i % $Nk == 4) {
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$temp = self::SubWord($temp);
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}
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for ($t = 0; $t < 4; ++$t) {
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$w[$i][$t] = $w[$i - $Nk][$t] ^ $temp[$t];
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}
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}
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return $w;
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}
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protected static function SubWord($w)
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{ // apply SBox to 4-byte word w
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for ($i = 0; $i < 4; ++$i) {
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$w[$i] = self::$Sbox[$w[$i]];
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}
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return $w;
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}
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protected static function RotWord($w)
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{ // rotate 4-byte word w left by one byte
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$tmp = $w[0];
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for ($i = 0; $i < 3; ++$i) {
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$w[$i] = $w[$i + 1];
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}
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$w[3] = $tmp;
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return $w;
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}
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/*
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* Unsigned right shift function, since PHP has neither >>> operator nor unsigned ints
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*
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* @param a number to be shifted (32-bit integer)
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* @param b number of bits to shift a to the right (0..31)
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* @return a right-shifted and zero-filled by b bits
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*/
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protected static function urs($a, $b)
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{
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$a &= 0xffffffff;
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$b &= 0x1f; // (bounds check)
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if ($a & 0x80000000 && $b > 0) { // if left-most bit set
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$a = ($a >> 1) & 0x7fffffff; // right-shift one bit & clear left-most bit
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$a = $a >> ($b - 1); // remaining right-shifts
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} else { // otherwise
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$a = ($a >> $b); // use normal right-shift
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}
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return $a;
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}
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/**
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* Encrypt a text using AES encryption in Counter mode of operation
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* - see http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf.
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*
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* Unicode multi-byte character safe
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*
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* @param plaintext source text to be encrypted
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* @param password the password to use to generate a key
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* @param nBits number of bits to be used in the key (128, 192, or 256)
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*
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* @return encrypted text
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*/
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public static function AESEncryptCtr($plaintext, $password, $nBits)
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{
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$blockSize = 16; // block size fixed at 16 bytes / 128 bits (Nb=4) for AES
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if (!($nBits == 128 || $nBits == 192 || $nBits == 256)) {
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return '';
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} // standard allows 128/192/256 bit keys
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// note PHP (5) gives us plaintext and password in UTF8 encoding!
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// use AES itself to encrypt password to get cipher key (using plain password as source for
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// key expansion) - gives us well encrypted key
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$nBytes = $nBits / 8; // no bytes in key
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$pwBytes = array();
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for ($i = 0; $i < $nBytes; ++$i) {
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$pwBytes[$i] = ord(substr($password, $i, 1)) & 0xff;
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}
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$key = self::Cipher($pwBytes, self::KeyExpansion($pwBytes));
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$key = array_merge($key, array_slice($key, 0, $nBytes - 16)); // expand key to 16/24/32 bytes long
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// initialise counter block (NIST SP800-38A <20>B.2): millisecond time-stamp for nonce in
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// 1st 8 bytes, block counter in 2nd 8 bytes
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$counterBlock = array();
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$nonce = floor(microtime(true) * 1000); // timestamp: milliseconds since 1-Jan-1970
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$nonceSec = floor($nonce / 1000);
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$nonceMs = $nonce % 1000;
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// encode nonce with seconds in 1st 4 bytes, and (repeated) ms part filling 2nd 4 bytes
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for ($i = 0; $i < 4; ++$i) {
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$counterBlock[$i] = self::urs($nonceSec, $i * 8) & 0xff;
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}
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for ($i = 0; $i < 4; ++$i) {
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$counterBlock[$i + 4] = $nonceMs & 0xff;
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}
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// and convert it to a string to go on the front of the ciphertext
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$ctrTxt = '';
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for ($i = 0; $i < 8; ++$i) {
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$ctrTxt .= chr($counterBlock[$i]);
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}
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// generate key schedule - an expansion of the key into distinct Key Rounds for each round
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$keySchedule = self::KeyExpansion($key);
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$blockCount = ceil(strlen($plaintext) / $blockSize);
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$ciphertxt = array(); // ciphertext as array of strings
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for ($b = 0; $b < $blockCount; ++$b) {
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// set counter (block #) in last 8 bytes of counter block (leaving nonce in 1st 8 bytes)
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// done in two stages for 32-bit ops: using two words allows us to go past 2^32 blocks (68GB)
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for ($c = 0; $c < 4; ++$c) {
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$counterBlock[15 - $c] = self::urs($b, $c * 8) & 0xff;
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}
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for ($c = 0; $c < 4; ++$c) {
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$counterBlock[15 - $c - 4] = self::urs($b / 0x100000000, $c * 8);
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}
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$cipherCntr = self::Cipher($counterBlock, $keySchedule); // -- encrypt counter block --
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// block size is reduced on final block
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$blockLength = $b < $blockCount - 1 ? $blockSize : (strlen($plaintext) - 1) % $blockSize + 1;
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$cipherByte = array();
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for ($i = 0; $i < $blockLength; ++$i) { // -- xor plaintext with ciphered counter byte-by-byte --
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$cipherByte[$i] = $cipherCntr[$i] ^ ord(substr($plaintext, $b * $blockSize + $i, 1));
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$cipherByte[$i] = chr($cipherByte[$i]);
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}
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$ciphertxt[$b] = implode('', $cipherByte); // escape troublesome characters in ciphertext
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}
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// implode is more efficient than repeated string concatenation
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$ciphertext = $ctrTxt.implode('', $ciphertxt);
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$ciphertext = base64_encode($ciphertext);
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return $ciphertext;
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}
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/**
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* Decrypt a text encrypted by AES in counter mode of operation.
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*
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* @param ciphertext source text to be decrypted
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* @param password the password to use to generate a key
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* @param nBits number of bits to be used in the key (128, 192, or 256)
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*
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* @return decrypted text
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*/
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public static function AESDecryptCtr($ciphertext, $password, $nBits)
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{
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$blockSize = 16; // block size fixed at 16 bytes / 128 bits (Nb=4) for AES
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if (!($nBits == 128 || $nBits == 192 || $nBits == 256)) {
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return '';
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} // standard allows 128/192/256 bit keys
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$ciphertext = base64_decode($ciphertext);
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// use AES to encrypt password (mirroring encrypt routine)
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$nBytes = $nBits / 8; // no bytes in key
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$pwBytes = array();
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for ($i = 0; $i < $nBytes; ++$i) {
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$pwBytes[$i] = ord(substr($password, $i, 1)) & 0xff;
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}
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$key = self::Cipher($pwBytes, self::KeyExpansion($pwBytes));
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$key = array_merge($key, array_slice($key, 0, $nBytes - 16)); // expand key to 16/24/32 bytes long
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// recover nonce from 1st element of ciphertext
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$counterBlock = array();
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$ctrTxt = substr($ciphertext, 0, 8);
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for ($i = 0; $i < 8; ++$i) {
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$counterBlock[$i] = ord(substr($ctrTxt, $i, 1));
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}
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// generate key schedule
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$keySchedule = self::KeyExpansion($key);
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// separate ciphertext into blocks (skipping past initial 8 bytes)
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$nBlocks = ceil((strlen($ciphertext) - 8) / $blockSize);
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$ct = array();
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for ($b = 0; $b < $nBlocks; ++$b) {
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$ct[$b] = substr($ciphertext, 8 + $b * $blockSize, 16);
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}
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$ciphertext = $ct; // ciphertext is now array of block-length strings
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// plaintext will get generated block-by-block into array of block-length strings
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$plaintxt = array();
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for ($b = 0; $b < $nBlocks; ++$b) {
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// set counter (block #) in last 8 bytes of counter block (leaving nonce in 1st 8 bytes)
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for ($c = 0; $c < 4; ++$c) {
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$counterBlock[15 - $c] = self::urs($b, $c * 8) & 0xff;
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}
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for ($c = 0; $c < 4; ++$c) {
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$counterBlock[15 - $c - 4] = self::urs(($b + 1) / 0x100000000 - 1, $c * 8) & 0xff;
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}
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$cipherCntr = self::Cipher($counterBlock, $keySchedule); // encrypt counter block
|
||
|
||
$plaintxtByte = array();
|
||
for ($i = 0; $i < strlen($ciphertext[$b]); ++$i) {
|
||
// -- xor plaintext with ciphered counter byte-by-byte --
|
||
$plaintxtByte[$i] = $cipherCntr[$i] ^ ord(substr($ciphertext[$b], $i, 1));
|
||
$plaintxtByte[$i] = chr($plaintxtByte[$i]);
|
||
}
|
||
$plaintxt[$b] = implode('', $plaintxtByte);
|
||
}
|
||
|
||
// join array of blocks into single plaintext string
|
||
$plaintext = implode('', $plaintxt);
|
||
|
||
return $plaintext;
|
||
}
|
||
|
||
/**
|
||
* AES encryption in CBC mode. This is the standard mode (the CTR methods
|
||
* actually use Rijndael-128 in CTR mode, which - technically - isn't AES).
|
||
* The data length is tucked as a 32-bit unsigned integer (little endian)
|
||
* after the ciphertext. It supports AES-128, AES-192 and AES-256.
|
||
*
|
||
* @since 3.0.1
|
||
*
|
||
* @author Nicholas K. Dionysopoulos
|
||
*
|
||
* @param string $plaintext The data to encrypt
|
||
* @param string $password Encryption password
|
||
* @param int $nBits Encryption key size. Can be 128, 192 or 256
|
||
*
|
||
* @return string The ciphertext
|
||
*/
|
||
public static function AESEncryptCBC($plaintext, $password, $nBits = 128)
|
||
{
|
||
if (!($nBits == 128 || $nBits == 192 || $nBits == 256)) {
|
||
return false;
|
||
} // standard allows 128/192/256 bit keys
|
||
if (!function_exists('mcrypt_module_open')) {
|
||
return false;
|
||
}
|
||
|
||
// Try to fetch cached key/iv or create them if they do not exist
|
||
$lookupKey = $password.'-'.$nBits;
|
||
if (array_key_exists($lookupKey, self::$passwords)) {
|
||
$key = self::$passwords[$lookupKey]['key'];
|
||
$iv = self::$passwords[$lookupKey]['iv'];
|
||
} else {
|
||
// use AES itself to encrypt password to get cipher key (using plain password as source for
|
||
// key expansion) - gives us well encrypted key
|
||
$nBytes = $nBits / 8; // no bytes in key
|
||
$pwBytes = array();
|
||
for ($i = 0; $i < $nBytes; ++$i) {
|
||
$pwBytes[$i] = ord(substr($password, $i, 1)) & 0xff;
|
||
}
|
||
$key = self::Cipher($pwBytes, self::KeyExpansion($pwBytes));
|
||
$key = array_merge($key, array_slice($key, 0, $nBytes - 16)); // expand key to 16/24/32 bytes long
|
||
$newKey = '';
|
||
foreach ($key as $int) {
|
||
$newKey .= chr($int);
|
||
}
|
||
$key = $newKey;
|
||
|
||
// Create an Initialization Vector (IV) based on the password, using the same technique as for the key
|
||
$nBytes = 16; // AES uses a 128 -bit (16 byte) block size, hence the IV size is always 16 bytes
|
||
$pwBytes = array();
|
||
for ($i = 0; $i < $nBytes; ++$i) {
|
||
$pwBytes[$i] = ord(substr($password, $i, 1)) & 0xff;
|
||
}
|
||
$iv = self::Cipher($pwBytes, self::KeyExpansion($pwBytes));
|
||
$newIV = '';
|
||
foreach ($iv as $int) {
|
||
$newIV .= chr($int);
|
||
}
|
||
$iv = $newIV;
|
||
|
||
self::$passwords[$lookupKey]['key'] = $key;
|
||
self::$passwords[$lookupKey]['iv'] = $iv;
|
||
}
|
||
|
||
$td = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, '');
|
||
mcrypt_generic_init($td, $key, $iv);
|
||
$ciphertext = mcrypt_generic($td, $plaintext);
|
||
mcrypt_generic_deinit($td);
|
||
|
||
$ciphertext .= pack('V', strlen($plaintext));
|
||
|
||
return $ciphertext;
|
||
}
|
||
|
||
/**
|
||
* AES decryption in CBC mode. This is the standard mode (the CTR methods
|
||
* actually use Rijndael-128 in CTR mode, which - technically - isn't AES).
|
||
*
|
||
* Supports AES-128, AES-192 and AES-256. It supposes that the last 4 bytes
|
||
* contained a little-endian unsigned long integer representing the unpadded
|
||
* data length.
|
||
*
|
||
* @since 3.0.1
|
||
*
|
||
* @author Nicholas K. Dionysopoulos
|
||
*
|
||
* @param string $ciphertext The data to encrypt
|
||
* @param string $password Encryption password
|
||
* @param int $nBits Encryption key size. Can be 128, 192 or 256
|
||
*
|
||
* @return string The plaintext
|
||
*/
|
||
public static function AESDecryptCBC($ciphertext, $password, $nBits = 128)
|
||
{
|
||
if (!($nBits == 128 || $nBits == 192 || $nBits == 256)) {
|
||
return false;
|
||
} // standard allows 128/192/256 bit keys
|
||
if (!function_exists('mcrypt_module_open')) {
|
||
return false;
|
||
}
|
||
|
||
// Try to fetch cached key/iv or create them if they do not exist
|
||
$lookupKey = $password.'-'.$nBits;
|
||
if (array_key_exists($lookupKey, self::$passwords)) {
|
||
$key = self::$passwords[$lookupKey]['key'];
|
||
$iv = self::$passwords[$lookupKey]['iv'];
|
||
} else {
|
||
// use AES itself to encrypt password to get cipher key (using plain password as source for
|
||
// key expansion) - gives us well encrypted key
|
||
$nBytes = $nBits / 8; // no bytes in key
|
||
$pwBytes = array();
|
||
for ($i = 0; $i < $nBytes; ++$i) {
|
||
$pwBytes[$i] = ord(substr($password, $i, 1)) & 0xff;
|
||
}
|
||
$key = self::Cipher($pwBytes, self::KeyExpansion($pwBytes));
|
||
$key = array_merge($key, array_slice($key, 0, $nBytes - 16)); // expand key to 16/24/32 bytes long
|
||
$newKey = '';
|
||
foreach ($key as $int) {
|
||
$newKey .= chr($int);
|
||
}
|
||
$key = $newKey;
|
||
|
||
// Create an Initialization Vector (IV) based on the password, using the same technique as for the key
|
||
$nBytes = 16; // AES uses a 128 -bit (16 byte) block size, hence the IV size is always 16 bytes
|
||
$pwBytes = array();
|
||
for ($i = 0; $i < $nBytes; ++$i) {
|
||
$pwBytes[$i] = ord(substr($password, $i, 1)) & 0xff;
|
||
}
|
||
$iv = self::Cipher($pwBytes, self::KeyExpansion($pwBytes));
|
||
$newIV = '';
|
||
foreach ($iv as $int) {
|
||
$newIV .= chr($int);
|
||
}
|
||
$iv = $newIV;
|
||
|
||
self::$passwords[$lookupKey]['key'] = $key;
|
||
self::$passwords[$lookupKey]['iv'] = $iv;
|
||
}
|
||
|
||
// Read the data size
|
||
$data_size = unpack('V', substr($ciphertext, -4));
|
||
|
||
// Decrypt
|
||
$td = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, '');
|
||
mcrypt_generic_init($td, $key, $iv);
|
||
$plaintext = mdecrypt_generic($td, substr($ciphertext, 0, -4));
|
||
mcrypt_generic_deinit($td);
|
||
|
||
// Trim padding, if necessary
|
||
if (strlen($plaintext) > $data_size) {
|
||
$plaintext = substr($plaintext, 0, $data_size);
|
||
}
|
||
|
||
return $plaintext;
|
||
}
|
||
}
|