PHP AES加密学习札记

<?php  //--------第一种AES-CBC加密方案--------  //仅为理解之用  $cipher = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, ''); #128位 = 16字节 iv必须16字节  $key128 = '1234567890123456';  $iv =  '1234567890123456';  $cleartext = 'hello'; #待加密的字符串  if (mcrypt_generic_init($cipher, $key128, $iv) != -1)  {      // PHP pads with NULL bytes if $cleartext is not a multiple of the block size..      //如果$cleartext不是128位也就是16字节的倍数，补充NULL字符满足这个条件，返回的结果的长度一样      $cipherText = mcrypt_generic($cipher,$cleartext );      mcrypt_generic_deinit($cipher);            // Display the result in hex.      //很明显，结果也是16字节的倍数.1个字节用两位16进制表示，所以下面输出的是32的倍数位16进制的字符串       echo '第一种AES加密方案:<br>';      printf("128-bit encrypted result:\n%s\n\n",bin2hex($cipherText));      echo '<br>';echo '<br>';  }  //--------第一种AES加密方案--------  ?> 

<?php  //--------第二种AES-ECB加密方案--------  //加密  echo '第二种AES加密方案:<br>';  $key = '1234567890123456';  $content = 'hello';  $padkey = pad2Length($key,16);  $cipher = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_ECB, '');  $iv_size = mcrypt_enc_get_iv_size($cipher);  $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND); #IV自动生成？  echo '自动生成iv的长度:'.strlen($iv).'位:'.bin2hex($iv).'<br>';  if (mcrypt_generic_init($cipher, pad2Length($key,16), $iv) != -1)  {      // PHP pads with NULL bytes if $content is not a multiple of the block size..      $cipherText = mcrypt_generic($cipher,pad2Length($content,16) );      mcrypt_generic_deinit($cipher);      mcrypt_module_close($cipher);           // Display the result in hex.      printf("128-bit encrypted result:\n%s\n\n",bin2hex($cipherText));      print("<br />");       }  //解密  $mw = bin2hex($cipherText);  $td = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_ECB, '');  if (mcrypt_generic_init($td, $padkey, $iv) != -1)  {      $p_t = mdecrypt_generic($td, hexToStr($mw));      mcrypt_generic_deinit($td);      mcrypt_module_close($td);           $p_t = trimEnd($p_t);      echo '解密:';      print($p_t);      print("<br />");      print(bin2hex($p_t));      echo '<br><br>';  }  //将$text补足$padlen倍数的长度  function pad2Length($text, $padlen){      $len = strlen($text)%$padlen;      $res = $text;      $span = $padlen-$len;      for($i=0; $i<$span; $i++){          $res .= chr($span);      }      return $res;  }  //将解密后多余的长度去掉(因为在加密的时候 补充长度满足block_size的长度)  function trimEnd($text){      $len = strlen($text);      $c = $text[$len-1];      if(ord($c) <$len){          for($i=$len-ord($c); $i<$len; $i++){              if($text[$i] != $c){                  return $text;              }          }          return substr($text, 0, $len-ord($c));      }      return $text;  }  //16进制的转为2进制字符串  function hexToStr($hex)   {       $bin="";       for($i=0; $i<strlen($hex)-1; $i+=2)       {          $bin.=chr(hexdec($hex[$i].$hex[$i+1]));       }      return $bin;   }  //--------第二种AES加密方案--------  

<?php  //--------第三种AES-ECB加密方案--------  echo '第三种AES加密方案:<br>';  $key = '1234567890123456';  $key = pad2Length($key,16);  $iv = 'asdff';  $content = 'hello';  $content = pad2Length($content,16);  $AESed =  bin2hex( mcrypt_encrypt(MCRYPT_RIJNDAEL_128,$key,$content,MCRYPT_MODE_ECB,$iv) ); #加密  echo "128-bit encrypted result:".$AESed.'<br>';  $jiemi = mcrypt_decrypt(MCRYPT_RIJNDAEL_128,$key,hexToStr($AESed),MCRYPT_MODE_ECB,$iv); #解密  echo '解密:';  echo trimEnd($jiemi);  //--------第三种AES加密方案--------  ?>#KEY长度无限制，IV长度必须是block_size的倍数#如果是MCRYPT_MODE_ECB加密，结果与KEY有关，与IV无关#如果是MCRYPT_MODE_CBC加密，结果与KEY有关，与IV有关