PHP AES encryption study notes

<?php  
//--------第一种AES-CBC加密方案--------  
//仅为理解之用  
$cipher = mcrypt_module_open(MCRYPT_RIJNDAEL_128, &#39;&#39;, MCRYPT_MODE_CBC, &#39;&#39;); #128位 = 16字节 iv必须16字节  
$key128 = &#39;1234567890123456&#39;;  
$iv =  &#39;1234567890123456&#39;;  
$cleartext = &#39;hello&#39;; #待加密的字符串  
if (mcrypt_generic_init($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 &#39;第一种AES加密方案:<br>&#39;;  
    printf("128-bit encrypted result:\n%s\n\n",bin2hex($cipherText));  
    echo &#39;<br>&#39;;echo &#39;<br>&#39;;  
}  
//--------第一种AES加密方案--------  
?> 

转载来源：http://www.chilkatsoft.com/p/php_aes.asp http://www.cnblogs.com/adylee/archive/2007/09/14/893438.html 转载来源：http://blog.csdn.net/shushengsky/archive/2009/12/13/4961861.aspx

<?php  
//--------第二种AES-ECB加密方案--------  
//加密  
echo &#39;第二种AES加密方案:<br>&#39;;  
$key = &#39;1234567890123456&#39;;  
$content = &#39;hello&#39;;  
$padkey = pad2Length($key,16);  
$cipher = mcrypt_module_open(MCRYPT_RIJNDAEL_128, &#39;&#39;, MCRYPT_MODE_ECB, &#39;&#39;);  
$iv_size = mcrypt_enc_get_iv_size($cipher);  
$iv = mcrypt_create_iv($iv_size, MCRYPT_RAND); #IV自动生成？  
echo &#39;自动生成iv的长度:&#39;.strlen($iv).&#39;位:&#39;.bin2hex($iv).&#39;<br>&#39;;  
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);  
$td = mcrypt_module_open(MCRYPT_RIJNDAEL_128, &#39;&#39;, MCRYPT_MODE_ECB, &#39;&#39;);  
if (mcrypt_generic_init($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 &#39;解密:&#39;;  
    print($p_t);  
    print("<br />");  
    print(bin2hex($p_t));  
    echo &#39;<br><br>&#39;;  
}  
//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 &#39;第三种AES加密方案:<br>&#39;;  
$key = &#39;1234567890123456&#39;;  
$key = pad2Length($key,16);  
$iv = &#39;asdff&#39;;  
$content = &#39;hello&#39;;  
$content = pad2Length($content,16);  
$AESed =  bin2hex( mcrypt_encrypt(MCRYPT_RIJNDAEL_128,$key,$content,MCRYPT_MODE_ECB,$iv) ); #加密  
echo "128-bit encrypted result:".$AESed.&#39;<br>&#39;;  
$jiemi = mcrypt_decrypt(MCRYPT_RIJNDAEL_128,$key,hexToStr($AESed),MCRYPT_MODE_ECB,$iv); #解密  
echo &#39;解密:&#39;;  
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