使用Mcrypt加密/解密文件 [英] Encrypting / Decrypting file with Mcrypt

问题描述

尝试编写一些将加密或解密文件的函数，并使用这里找到的类来尝试完成此操作：

Trying to write a couple of functions that will encrypt or decrypt a file and am using the class found here to try and accomplish this:

http://www.itnewb.com/v/PHP-Encryption- Decryption-Using-the-MCrypt-Library-libmcrypt

下面的加密功能似乎有效，因为它似乎加密了文件并将其放在预期目录。我正在尝试解密该文件，它只是死了与消息无法完成解密（这是编码在那里...）没有什么在php错误日志，所以我不知道为什么它失败但是，对于我来说，随着mcrypt是全新的，我更倾向于相信我在这里做错事...

The encryption function below seems to work, in that it appears to encrypt the file and place it in the intended directory. I'm trying to decrypt the file now, and it just dies with the message "Failed to complete decryption" (which is coded in there...) There's nothing in the php error logs, so I'm not sure why it's failing, but as mcrypt is entirely new to me, I'm more than inclined to believe I'm doing something wrong here...

这里是功能： p>

Here are the functions:

//ENCRYPT FILE
    function encryptFile() {
        global $cryptastic;
        $pass = PGPPASS;
        $salt = PGPSALT;
        $key = $cryptastic->pbkdf2($pass, $salt, 1000, 32) or die("Failed to generate secret key.");

        if ($handle = opendir(PATH.'/ftpd')) {
            while (false !== ($file = readdir($handle))) {
                if ($file != "." && $file != "..") {
                    $newfile = PATH.'/encrypted/'.$file.'.txt';
                    $msg = file_get_contents(PATH.'/ftpd/'.$file);
                    $encrypted = $cryptastic->encrypt($msg, $key) or die("Failed to complete encryption.");
                    $nfile = fopen($newfile, 'w');
                    fwrite($nfile, $encrypted);
                    fclose($nfile);
                    unlink(PATH.'/ftpd/'.$file);

                }
            }
            closedir($handle);
        }       


//DECRYPT FILE
    function inFTP() {
        global $cryptastic;
        $pass = PGPPASS;
        $salt = PGPSALT;
        $key = $cryptastic->pbkdf2($pass, $salt, 1000, 32) or die("Failed to generate secret key.");

        if ($handle = opendir(PATH.'/encrypted')) {
            while (false !== ($file = readdir($handle))) {
                if ($file != "." && $file != "..") {
                    $newfile = PATH.'/decrypted/'.$file;
                    $msg = PATH.'/encrypted/'.$file;
                    $decrypted = $cryptastic->decrypt($msg, $key) or die("Failed to complete decryption.");
                    $nfile = fopen($newfile, 'w');
                    fwrite($nfile, $decrypted);
                    fclose($nfile);
                    //unlink(PATH.'/encrypted/'.$file);

                }
            }
            closedir($handle);
        }       
        //$crypt->decrypt($file);
    }

推荐答案

尝试这个PHP5类进行加密使用mcrypt。在这种情况下，它使用AES加密。您将要更改您使用它的每个网站的密钥。如果你不使用它，至少可以指导你编写自己的版本。

Try this PHP5 class for encryption using mcrypt. In this case it's using AES encryption. You'll want to change the key for each site you use it on. If you don't use it at least it may guide you on writing your own version of it.

<?php

class Encryption
{
    const CIPHER = MCRYPT_RIJNDAEL_128; // Rijndael-128 is AES
    const MODE   = MCRYPT_MODE_CBC;

    /* Cryptographic key of length 16, 24 or 32. NOT a password! */
    private $key;
    public function __construct($key) {
        $this->key = $key;
    }

    public function encrypt($plaintext) {
        $ivSize = mcrypt_get_iv_size(self::CIPHER, self::MODE);
        $iv = mcrypt_create_iv($ivSize, MCRYPT_DEV_URANDOM);
        $ciphertext = mcrypt_encrypt(self::CIPHER, $this->key, $plaintext, self::MODE, $iv);
        return base64_encode($iv.$ciphertext);
    }

    public function decrypt($ciphertext) {
        $ciphertext = base64_decode($ciphertext);
        $ivSize = mcrypt_get_iv_size(self::CIPHER, self::MODE);
        if (strlen($ciphertext) < $ivSize) {
            throw new Exception('Missing initialization vector');
        }

        $iv = substr($ciphertext, 0, $ivSize);
        $ciphertext = substr($ciphertext, $ivSize);
        $plaintext = mcrypt_decrypt(self::CIPHER, $this->key, $ciphertext, self::MODE, $iv);
        return rtrim($plaintext, "\0");
    }
}

用法：

$key = /* CRYPTOGRAPHIC!!! key */;
$crypt = new Encryption($key);
$encrypted_string = $crypt->encrypt('this is a test');
$decrypted_string = $crypt->decrypt($encrypted_string); // this is a test

注意：

• 此类不适用于二进制数据（可能以NUL字节结尾）


• 此类不提供经过身份验证的加密。

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