PHP等效于Java Triple DES加密/解密

Question

我试图使用PHP mcrypt函数解密由Java Triple DES函数加密的密钥,但没有运气.在下面找到java代码

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;


public class Encrypt3DES {

     private byte[] key;
     private byte[] initializationVector;

    public Encrypt3DES(){

    }

    public String encryptText(String plainText, String key) throws Exception{

         //----  Use specified 3DES key and IV from other source --------------
        byte[] plaintext = plainText.getBytes();
        byte[] myIV = key.getBytes();
        byte[] tdesKeyData = {(byte)0xA2, (byte)0x15, (byte)0x37, (byte)0x08, (byte)0xCA, (byte)0x62,
        (byte)0xC1, (byte)0xD2, (byte)0xF7, (byte)0xF1, (byte)0x93, (byte)0xDF,
        (byte)0xD2, (byte)0x15, (byte)0x4F, (byte)0x79, (byte)0x06, (byte)0x67,
        (byte)0x7A, (byte)0x82, (byte)0x94, (byte)0x16, (byte)0x32, (byte)0x95};

        Cipher c3des = Cipher.getInstance("DESede/CBC/PKCS5Padding");
        SecretKeySpec    myKey = new SecretKeySpec(tdesKeyData, "DESede");
        IvParameterSpec ivspec = new IvParameterSpec(myIV);
           c3des.init(Cipher.ENCRYPT_MODE, myKey, ivspec);
        byte[] cipherText = c3des.doFinal(plaintext);
        sun.misc.BASE64Encoder obj64=new sun.misc.BASE64Encoder();
        return obj64.encode(cipherText);

    }

    public String decryptText(String encryptText, String key) throws Exception{


        byte[] initializationVector = key.getBytes();
        byte[] tdesKeyData = {(byte)0xA2, (byte)0x15, (byte)0x37, (byte)0x08, (byte)0xCA, (byte)0x62,
        (byte)0xC1, (byte)0xD2, (byte)0xF7, (byte)0xF1, (byte)0x93, (byte)0xDF,
        (byte)0xD2, (byte)0x15, (byte)0x4F, (byte)0x79, (byte)0x06, (byte)0x67,
        (byte)0x7A, (byte)0x82, (byte)0x94, (byte)0x16, (byte)0x32, (byte)0x95};


          byte[] encData = new sun.misc.BASE64Decoder().decodeBuffer(encryptText);
          Cipher decipher = Cipher.getInstance("DESede/CBC/PKCS5Padding");
          SecretKeySpec myKey = new SecretKeySpec(tdesKeyData, "DESede");
          IvParameterSpec ivspec = new IvParameterSpec(initializationVector);
          decipher.init(Cipher.DECRYPT_MODE, myKey, ivspec);
          byte[] plainText = decipher.doFinal(encData);
          return new String(plainText);

    }
}

我想编写一个等同于上面的decryptText Java函数的PHP函数.我发现难以生成由加密的Java代码生成的确切IV值,这是解密所需的.

Answer 1

这是PHP相当于Java代码的(我抄在征求意见的PKCS#5填充20-Sep-2006 07:56的的mcrypt参考)

function encryptText($plainText, $key) {
    $keyData = "\xA2\x15\x37\x08\xCA\x62\xC1\xD2"
        . "\xF7\xF1\x93\xDF\xD2\x15\x4F\x79\x06"
        . "\x67\x7A\x82\x94\x16\x32\x95";

    $padded = pkcs5_pad($plainText,
        mcrypt_get_block_size("tripledes", "cbc"));

    $encText = mcrypt_encrypt("tripledes", $keyData, $padded, "cbc", $key);

    return base64_encode($encText);
}

function decryptText($encryptText, $key) {
    $keyData = "\xA2\x15\x37\x08\xCA\x62\xC1\xD2"
        . "\xF7\xF1\x93\xDF\xD2\x15\x4F\x79\x06"
        . "\x67\x7A\x82\x94\x16\x32\x95";

    $cipherText = base64_decode($encryptText);

    $res = mcrypt_decrypt("tripledes", $keyData, $cipherText, "cbc", $key);

    $resUnpadded = pkcs5_unpad($res);

    return $resUnpadded;
}


function pkcs5_pad ($text, $blocksize)
{
    $pad = $blocksize - (strlen($text) % $blocksize);
    return $text . str_repeat(chr($pad), $pad);
}

function pkcs5_unpad($text)
{
    $pad = ord($text{strlen($text)-1});
    if ($pad > strlen($text)) return false;
    if (strspn($text, chr($pad), strlen($text) - $pad) != $pad) return false;
    return substr($text, 0, -1 * $pad);
}

但是你应该注意一些问题:

• 在您的Java代码中,您调用时String.getBytes()不指示编码.如果明文包含非ASCII字符(如变音符号),则会使您的代码不可移植,因为Java使用系统默认字符集.如果你可以改变,我当然会这样做.我建议你在双方都使用utf-8(Java和PHP).
• 您已对密码进行了硬编码,并将IV用作"密钥".我绝不是一个加密专家,但对我而言,它只是感觉不对,可能会造成巨大的安全漏洞.
• 创建一个随机IV,并在消息的开头或结尾处连接它.由于IV的大小是AFAIK等于你的密码的块大小,你只需从开头或结尾删除那么多字节,并且很容易将IV与消息分开.
• 至于密钥,最好使用某种密钥派生方法从"人工生成"密码生成具有正确大小的密钥.

当然,如果您必须满足某些要求,则无法更改方法.