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PHP implementation of AES256 encryption algorithm example_PHP tutorial
- WBOYOriginal
- 2016-07-13 10:18:36966browse
Example of PHP implementing AES256 encryption algorithm
This article describes the example of PHP implementing AES256 encryption algorithm, which is a relatively common encryption algorithm. Share it with everyone for your reference. The details are as follows:
aes.class.php file is as follows:
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/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ /* AES implementation in PHP (c) Chris Veness 2005-2011. Right of free use is granted for all */ /* commercial or non-commercial use under CC-BY license. No warranty of any form is offered. */ /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
class Aes {
/** * 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 $output; }
private static function addRoundKey($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 $state; }
private static function subBytes($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 $s; }
private static function shiftRows($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 $s; // see fp.gladman.plus.com/cryptography_technology/rijndael/aes.spec.311.pdf }
private static function mixColumns($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]; } else if ($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 $w; }
private static function subWord($w) { // apply SBox to 4-byte word w for ($i=0; $i<4; $i++) $w[$i] = self::$sBox[$w[$i]]; return $w; }
private static function rotWord($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; }
// sBox is pre-computed multiplicative inverse in GF(2^8) used in subBytes and keyExpansion [§5.1.1] private 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] private static $rCon = array( array(0x00, 0x00, 0x00, 0x00), array(0x01, 0x00, 0x00, 0x00), array(0x02, 0x00, 0x00, 0x00), array(0x04, 0x00, 0x00, 0x00), array(0x08, 0x00, 0x00, 0x00), array(0x10, 0x00, 0x00, 0x00), array(0x20, 0x00, 0x00, 0x00), array(0x40, 0x00, 0x00, 0x00), array(0x80, 0x00, 0x00, 0x00), array(0x1b, 0x00, 0x00, 0x00), array(0x36, 0x00, 0x00, 0x00) ); } ?> |
aesctr.class.php file is as follows:
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/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ /* AES counter (CTR) mode implementation in PHP (c) Chris Veness 2005-2011. Right of free use is */ /* granted for all commercial or non-commercial use under CC-BY license. No warranty of any */ /* form is offered. /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
class AesCtr extends Aes {
/** * Encrypt a text using AES encryption in Counter mode of operation * - see http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf * * Unicode multi-byte character safe * * @param plaintext source text to be encrypted * @param password the password to use to generate a key * @param nBits number of bits to be used in the key (128, 192, or 256) * @param keep keep 1:each not change 0:each change(default) * @return encrypted text */ public static function encrypt($plaintext, $password, $nBits, $keep=0) { $blockSize = 16; // block size fixed at 16 bytes / 128 bits (Nb=4) for AES if (!($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; $key = Aes::cipher($pwBytes, Aes::keyExpansion($pwBytes)); $key = array_merge($key, array_slice($key, 0, $nBytes-16)); // expand key to 16/24/32 bytes long
// initialise 1st 8 bytes of counter block with nonce (NIST SP800-38A §B.2): [0-1] = millisec, // [2-3] = random, [4-7] = seconds, giving guaranteed sub-ms uniqueness up to Feb 2106 $counterBlock = array();
if($keep==0){ $nonce = floor(microtime(true)*1000); // timestamp: milliseconds since 1-Jan-1970 $nonceMs = $nonce%1000; $nonceSec = floor($nonce/1000); $nonceRnd = floor(rand(0, 0xffff)); }else{ $nonce = 10000; $nonceMs = $nonce%1000; $nonceSec = floor($nonce/1000); $nonceRnd = 10000; }
for ($i=0; $i<2; $i++) $counterBlock[$i] = self::urs($nonceMs, $i*8) & 0xff; for ($i=0; $i<2; $i++) $counterBlock[$i+2] = self::urs($nonceRnd, $i*8) & 0xff; for ($i=0; $i<4; $i++) $counterBlock[$i+4] = self::urs($nonceSec, $i*8) & 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 $keySchedule = Aes::keyExpansion($key); //print_r($keySchedule);
$blockCount = ceil(strlen($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);
$cipherCntr = Aes::cipher($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 $ciphertext; }
/** * Decrypt a text encrypted by AES in counter mode of operation * * @param ciphertext source text to be decrypted * @param password the password to use to generate a key * @param nBits number of bits to be used in the key (128, 192, or 256) * @return decrypted text */ public static function decrypt($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; $key = Aes::cipher($pwBytes, Aes::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 $keySchedule = Aes::keyExpansion($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;
$cipherCntr = Aes::cipher($counterBlock, $keySchedule); // encrypt counter block
$plaintxtByte = array(); for ($i=0; $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 $plaintext; } /* * Unsigned right shift function, since PHP has neither >>> operator nor unsigned ints * * @param a number to be shifted (32-bit integer) * @param b number of bits to shift a to the right (0..31) * @return a right-shifted and zero-filled by b bits */ private static function urs($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; } } ?> |
Demo实例程序如下：
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';
$mstr = AesCtr::encrypt('Hello World', 'key', 256);
echo "Encrypt String : $mstr "; $dstr = AesCtr::decrypt($mstr, 'key', 256); echo "Decrypt String : $dstr "; echo 'each not change '; $mstr = AesCtr::encrypt('Hello World', 'key', 256, 1); // keep=1 echo "Encrypt String : $mstr "; $dstr = AesCtr::decrypt($mstr, 'key', 256); echo "Decrypt String : $dstr "; ?> |
Here is another introduction to another encryption and decryption method using PHP mcrypt:
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/* aes 256 encrypt
* @param String $ostr
* @param String $securekey
* @param String $type encrypt, decrypt
*/
function aes($ostr, $securekey, $type='encrypt'){
if($ostr==''){
return '';
}
$key = $securekey;
$iv = strrev($securekey);
$td = mcrypt_module_open('rijndael-256', '', 'ofb', '');
mcrypt_generic_init($td, $key, $iv);
$str = '';
switch($type){
case 'encrypt':
$str = base64_encode(mcrypt_generic($td, $ostr));
break;
case 'decrypt':
$str = mdecrypt_generic($td, base64_decode($ostr));
break;
}
mcrypt_generic_deinit($td);
return $str;
}
// Demo
$key = "fdipzone201314showmethemoney!@#$";
$str = "show me the money";
$ostr = aes($str, $key);
echo "String 1: $ostr "; $dstr = aes($ostr, $key, 'decrypt'); echo "String 2: $dstr "; |