CryptoJS AES加密和Java AES解密

Question

我只是问这个,因为我已经阅读了很多关于加密AES加密的帖子2天了,就在我以为我得到它的时候,我意识到我根本没有得到它.

这篇文章是我最接近我的问题,我有完全相同的问题,但没有答案:

CryptoJS AES加密和JAVA AES解密值不匹配

我尝试过很多方面,但我没有做对.

首先

我正在获取已经加密的字符串(我只获得了代码以了解它们是如何进行的),因此修改加密方式不是一种选择.这就是为什么所有类似的问题对我都没有用.

第二

我有权访问密钥,我可以修改它(所以如果需要,调整长度是一个选项).

加密在CryptoJS上完成,它们将加密的字符串作为GET参数发送.

GetParamsForAppUrl.prototype.generateUrlParams = function() {
const self = this;
 return new Promise((resolve, reject) => {
   const currentDateInMilliseconds = new Date().getTime();
   const secret = tokenSecret.secret;
   var encrypted = CryptoJS.AES.encrypt(self.authorization, secret);
   encrypted = encrypted.toString();
   self.urlParams = {
     token: encrypted,
     time: currentDateInMilliseconds
   };
   resolve();
 });
};

我可以使用CryptoJS在javascript上轻松解密这个:

var decrypted = CryptoJS.AES.decrypt(encrypted_string, secret);
    console.log(decrypted.toString(CryptoJS.enc.Utf8)); 

但出于安全考虑,我不想在Javascript上这样做,所以我试图在Java上解密它:

String secret = "secret";
byte[] cipherText = encrypted_string.getBytes("UTF8");
SecretKey secKey = new SecretKeySpec(secret.getBytes(), "AES");
Cipher aesCipher = Cipher.getInstance("AES");
aesCipher.init(Cipher.DECRYPT_MODE, secKey);
byte[] bytePlainText = aesCipher.doFinal(byteCipherText);
String myDecryptedText = = new String(bytePlainText);

在我知道我在做什么之前,我尝试了base64解码,添加了一些IV和我读过的很多东西,当然没有一个工作.

但是在我开始理解,有点,我正在做什么之后,我在上面编写了这个简单的脚本,并在帖子上得到了同样的错误:AES密钥长度无效

我不知道从哪里开始.在阅读了很多相关内容之后,解决方案似乎是哈希或填充,但是我无法控制加密方法,所以我无法真正散列秘密或填充它.

但正如我所说,我可以更改密钥,以便它可以匹配一些特定的长度,我已经尝试改变它,但是当我在黑暗中拍摄时,我真的不知道这是否是解决方案.

所以,我的问题基本上是,如果我得到加密的字符串(在第一个脚本的javascript中)和密钥,有没有办法解密它(用Java)？如果是这样,怎么办？

Answer 1

CryptoJS实现与OpenSSL相同的密钥派生功能,以及将IV放入加密数据的相同格式.因此,所有处理OpenSSL编码数据的Java代码都适用.

给出以下Javascript代码:

var text = "The quick brown fox jumps over the lazy dog.  ";
var secret = "René Über";
var encrypted = CryptoJS.AES.encrypt(text, secret);
encrypted = encrypted.toString();
console.log("Cipher text: " + encrypted);

我们得到密文:

U2FsdGVkX1+tsmZvCEFa/iGeSA0K7gvgs9KXeZKwbCDNCs2zPo+BXjvKYLrJutMK+hxTwl/hyaQLOaD7LLIRo2I5fyeRMPnroo6k8N9uwKk=

在Java方面,我们有

String secret = "René Über";
String cipherText = "U2FsdGVkX1+tsmZvCEFa/iGeSA0K7gvgs9KXeZKwbCDNCs2zPo+BXjvKYLrJutMK+hxTwl/hyaQLOaD7LLIRo2I5fyeRMPnroo6k8N9uwKk=";

byte[] cipherData = Base64.getDecoder().decode(cipherText);
byte[] saltData = Arrays.copyOfRange(cipherData, 8, 16);

MessageDigest md5 = MessageDigest.getInstance("MD5");
final byte[][] keyAndIV = GenerateKeyAndIV(32, 16, 1, saltData, secret.getBytes(StandardCharsets.UTF_8), md5);
SecretKeySpec key = new SecretKeySpec(keyAndIV[0], "AES");
IvParameterSpec iv = new IvParameterSpec(keyAndIV[1]);

byte[] encrypted = Arrays.copyOfRange(cipherData, 16, cipherData.length);
Cipher aesCBC = Cipher.getInstance("AES/CBC/PKCS5Padding");
aesCBC.init(Cipher.DECRYPT_MODE, key, iv);
byte[] decryptedData = aesCBC.doFinal(encrypted);
String decryptedText = new String(decryptedData, StandardCharsets.UTF_8);

System.out.println(decryptedText);

结果是:

The quick brown fox jumps over the lazy dog.  

这是我们开始的文字.表情符号,口音和变音符号也起作用.

GenerateKeyAndIV是一个辅助函数,它重新实现了OpenSSL的密钥派生函数EVP_BytesToKey(参见https://github.com/openssl/openssl/blob/master/crypto/evp/evp_key.c).

/**
 * Generates a key and an initialization vector (IV) with the given salt and password.
 * <p>
 * This method is equivalent to OpenSSL's EVP_BytesToKey function
 * (see https://github.com/openssl/openssl/blob/master/crypto/evp/evp_key.c).
 * By default, OpenSSL uses a single iteration, MD5 as the algorithm and UTF-8 encoded password data.
 * </p>
 * @param keyLength the length of the generated key (in bytes)
 * @param ivLength the length of the generated IV (in bytes)
 * @param iterations the number of digestion rounds 
 * @param salt the salt data (8 bytes of data or <code>null</code>)
 * @param password the password data (optional)
 * @param md the message digest algorithm to use
 * @return an two-element array with the generated key and IV
 */
public static byte[][] GenerateKeyAndIV(int keyLength, int ivLength, int iterations, byte[] salt, byte[] password, MessageDigest md) {

    int digestLength = md.getDigestLength();
    int requiredLength = (keyLength + ivLength + digestLength - 1) / digestLength * digestLength;
    byte[] generatedData = new byte[requiredLength];
    int generatedLength = 0;

    try {
        md.reset();

        // Repeat process until sufficient data has been generated
        while (generatedLength < keyLength + ivLength) {

            // Digest data (last digest if available, password data, salt if available)
            if (generatedLength > 0)
                md.update(generatedData, generatedLength - digestLength, digestLength);
            md.update(password);
            if (salt != null)
                md.update(salt, 0, 8);
            md.digest(generatedData, generatedLength, digestLength);

            // additional rounds
            for (int i = 1; i < iterations; i++) {
                md.update(generatedData, generatedLength, digestLength);
                md.digest(generatedData, generatedLength, digestLength);
            }

            generatedLength += digestLength;
        }

        // Copy key and IV into separate byte arrays
        byte[][] result = new byte[2][];
        result[0] = Arrays.copyOfRange(generatedData, 0, keyLength);
        if (ivLength > 0)
            result[1] = Arrays.copyOfRange(generatedData, keyLength, keyLength + ivLength);

        return result;

    } catch (DigestException e) {
        throw new RuntimeException(e);

    } finally {
        // Clean out temporary data
        Arrays.fill(generatedData, (byte)0);
    }
}

请注意,您必须安装Java Cryptography Extension(JCE)Unlimited Strength Jurisdiction Policy.否则,密钥大小为256的AES将无法工作并抛出异常:

java.security.InvalidKeyException: Illegal key size

更新

我已经取代奥拉·比尼的Java代码的EVP_BytesToKey,我在我的答案的第一个版本,搭配出更地道,更容易理解Java代码(见上文).

另请参阅如何解密使用AES使用openssl命令加密的Java文件？.