PHP实现AES256加密算法实例

本文实例讲述了PHP实现AES256加密算法的方法，是较为常见的一种加密算法。分享给大家供大家参考。具体如下：

aes.class.php文件如下：

<?php 
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ 
/* 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 licence. 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文件如下：

<?php 
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ 
/* 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 licence. 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; $i<strlen($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; 
 } 
  
 /* 
  * 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：

<?php  
require 'aes.class.php';   // AES PHP implementation 
require 'aesctr.class.php'; // AES Counter Mode implementation  
 
echo 'each change<br>'; 
 
$mstr = AesCtr::encrypt('Hello World', 'key', 256); 
echo "Encrypt String : $mstr<br />"; 
 
$dstr = AesCtr::decrypt($mstr, 'key', 256); 
echo "Decrypt String : $dstr<br />"; 
 
echo 'each not change<br>'; 
 
$mstr = AesCtr::encrypt('Hello World', 'key', 256, 1); // keep=1 
echo "Encrypt String : $mstr<br />"; 
 
$dstr = AesCtr::decrypt($mstr, 'key', 256); 
echo "Decrypt String : $dstr<br />"; 
?> 

这里再介绍另一使用 PHP mcrypt 加解密方法：

/* 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<br />"; 
 
$dstr = aes($ostr, $key, 'decrypt'); 
echo "String 2: $dstr<br />";

希望本文所述对大家php程序设计的学习有所帮助。