Question

我无法在Java中创建相当于php DES的解密，总是有不同的结果。这里是php-code我想复制的内容：

$key = substr(sha1("m",true),0,8); //8-byte key
$iv = mcrypt_encrypt (MCRYPT_DES,$key,hex2bin("0000000000000000"),MCRYPT_MODE_ECB); //get Iv
print(bin2hex($iv)."\n"); // "b5872289d3c49605"
$plain_text = "MZ4aXMCMO/TQAsZ2bYwagw==";
$plain_text = base64_decode($plain_text);
$cipher_text = mcrypt_decrypt (MCRYPT_DES, $key, $plain_text, MCRYPT_MODE_CFB, $iv);
print("\nThe ciphertext: ".$cipher_text);
print("\nThe expected  : "."489B4F2ADD728755");

和我的Java代码：

public static void desCipherDecrypt(String key, String encodedString) throws Exception {
    byte [] keyByte = Arrays.copyOf(DigestUtils.sha1(key),8);
    byte [] encodedByte = Base64.decodeBase64(encodedString);
    byte [] iv = DatatypeConverter.parseHexBinary("B5872289D3C49605"); //same as Iv in php

    AlgorithmParameterSpec paramSpec = new IvParameterSpec(iv);
    Cipher desCipherDecrypt;

    desCipherDecrypt = Cipher.getInstance("DES/CFB/NoPadding");
    DESKeySpec dks = new DESKeySpec(keyByte);
    SecretKeyFactory skf = SecretKeyFactory.getInstance("DES");
    SecretKey desKey = skf.generateSecret(dks);
    desCipherDecrypt.init(Cipher.DECRYPT_MODE, desKey,paramSpec);
    byte[] cryptByte = desCipherDecrypt.doFinal(encodedByte);

    System.out.println("resultBytes: "+Arrays.toString(cryptByte)+"\n");
    System.out.println("resultHex: "+DatatypeConverter.printHexBinary(cryptByte)+"\n");
    System.out.println("Decryption ended");
  }
...
desCipherDecrypt("m", "MZ4aXMCMO/TQAsZ2bYwagw==");

Answer 1

所以，这是一个愚蠢的错误，由于某种原因，我认为$ cipher_text是用Hex编码的，但它是错误的，它是纯文本，另一个原因是mcrypt_decrypt由于某种原因没有使用64位但8位块中的标准块。

毕竟答案将是，首先，使用CFB8：

desCipherDecrypt = Cipher.getInstance("DES/CFB8/NoPadding");

第二个读取结果字节，如纯文本

yte[] cryptByte = desCipherDecrypt.doFinal(encodedByte);
    for (int i = 0; i < cryptByte.length; i++ ){
                sResult += (char)(cryptByte[i]);
        }

在Java

1 个答案: