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
<pre lang="php">
<?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