Question

我在这里使用文件上传，在这里我做了base64编码图像到

$encodeimage =  base64_encode(file_get_contents($filename));

//这里我们得到了编码图像值**现在我得到了答案，之后我想加密base64编码值，我写下面的代码，但我无法获得加密值？

<?php
require_once 'Security.php'; 

 define ("MAX_SIZE","1000");
 $errors=0;
    $image =$_FILES["file"]["name"];//i got filename here
    $uploadedfile = $_FILES['file']['tmp_name'];
    $filetype = $_FILES['file']['type'];
      if ($image) 
      {
      $filename = stripslashes($_FILES['file']['name']);
      $extension = getExtension($filename);
      $extension = strtolower($extension);
     if (($extension != "jpg") && ($extension != "jpeg") && ($extension != "png") && ($extension != "gif")) 
      {
        $error_msg = ' Unknown Image extension ';
        $errors=1;
      }
     else{
         $size=filesize($_FILES['file']['tmp_name']);
        if ($size > MAX_SIZE*1024)
        {
         $error_msg = "You have exceeded the size limit";
         $errors=1;
        }

        if($extension=="jpg" || $extension=="jpeg" )
        {
        $uploadedfile = $_FILES['file']['tmp_name'];
        $src = imagecreatefromjpeg($uploadedfile);
        }
        else if($extension=="png")
        {
        $uploadedfile = $_FILES['file']['tmp_name'];
        $src = imagecreatefrompng($uploadedfile);
        }
        else 
        {
        $src = imagecreatefromgif($uploadedfile);
        }

        list($width,$height)=getimagesize($uploadedfile);

        $newwidth=600;
        /*$newheight=($height/$width)*$newwidth;*/
        $newheight=600;
        $tmp=imagecreatetruecolor($newwidth,$newheight);

        imagecopyresampled($tmp,$src,0,0,0,0,$newwidth,$newheight,$width,$height);

        $filename = $_FILES['file']['name'];

        imagejpeg($tmp,$filename,100);

        $encodeimage =  base64_encode(file_get_contents($filename));//here we got encodede image value

        $encrypt_image = "data:".$filetype."base64,".$encodeimage;

        $security = new Security();
        /*$string = $_POST['user_string'];*/
        $publicKey = $security->genRandString(32);
        $encryptedData = $security->encrypt($encrypt_image, $publicKey);

        imagedestroy($src);
        imagedestroy($tmp);
        }
        }

        function getExtension($str) {

                 $i = strrpos($str,".");
                 if (!$i) { return ""; } 

                 $l = strlen($str) - $i;
                 $ext = substr($str,$i+1,$l);
                 return $ext;
         }

        $id_proof = array("filename" =>$filename,
                          "base64_encodeimage" =>$encrypt_image,
                          "encryptedData" => $encryptedData,//getting null value here
                          "error_msg" =>$error_msg
                            );
        echo json_encode($id_proof);
?>

Security.php

<?php
class Security {

    // Private key
    public static $salt = 'Lu70K$i3pu5xf7*I8tNmd@x2oODwwDRr4&xjuyTh';


    // Encrypt a value using AES-256.
    public static function encrypt($plain, $key, $hmacSalt = null) {
        self::_checkKey($key, 'encrypt()');

        if ($hmacSalt === null) {
            $hmacSalt = self::$salt;
        }

        $key = substr(hash('sha256', $key . $hmacSalt), 0, 32); # Generate the encryption and hmac key

        $algorithm = MCRYPT_RIJNDAEL_128; # encryption algorithm
        $mode = MCRYPT_MODE_CBC; # encryption mode

        $ivSize = mcrypt_get_iv_size($algorithm, $mode); # Returns the size of the IV belonging to a specific cipher/mode combination
        $iv = mcrypt_create_iv($ivSize, MCRYPT_DEV_URANDOM); # Creates an initialization vector (IV) from a random source
        $ciphertext = $iv . mcrypt_encrypt($algorithm, $key, $plain, $mode, $iv); # Encrypts plaintext with given parameters
        $hmac = hash_hmac('sha256', $ciphertext, $key); # Generate a keyed hash value using the HMAC method
        return $hmac . $ciphertext;
    }

    // Check key
    protected static function _checkKey($key, $method) {
        if (strlen($key) < 32) {
            echo "Invalid public key $key, key must be at least 256 bits (32 bytes) long."; die();
        }
    }

    //Get Random String - Usefull for public key
    public function genRandString($length = 0) {
        $charset = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
        $str = '';
        $count = strlen($charset);
        while ($length-- > 0) {
            $str .= $charset[mt_rand(0, $count-1)];
        }
        return $str;
    }
}

Answer 1

如果问题是您或其他人无法解密，原因可能是您在评论集中使用的是AES 256，但在代码中您将算法设置为AES 128，您的意思是CRYPT_RIJNDAEL_256而不是CRYPT_RIJNDAEL_128 ？

当您不以静态方式使用加密功能时，还有一个原因是您的加密功能是静态的吗？

如何加密base64编码的值

1 个答案: