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