Question

我首先要描述我遇到的问题，然后给出我想要做的事情的一些背景知识。最后，我将粘贴一些相关的代码片段。

我正在尝试使用https://stackoverflow.com/a/992413/171993中指定的方法实现密钥加密/解密。如果我按原样使用该示例，它可以工作（虽然我确实注意到我需要重新实例化Cipher类，否则解密会产生垃圾）。但是，在我的实现中，我得到以下异常：

java.security.InvalidKeyException: Wrong algorithm: AES or Rijndael required
    at com.sun.crypto.provider.AESCrypt.init(AESCrypt.java:77)
    at com.sun.crypto.provider.CipherBlockChaining.init(CipherBlockChaining.java:91)
    at com.sun.crypto.provider.CipherCore.init(CipherCore.java:469)
    at com.sun.crypto.provider.AESCipher.engineInit(AESCipher.java:217)
    at javax.crypto.Cipher.implInit(Cipher.java:790)
    at javax.crypto.Cipher.chooseProvider(Cipher.java:848)
    at javax.crypto.Cipher.init(Cipher.java:1347)
    at javax.crypto.Cipher.init(Cipher.java:1281)
    at securitytest.SecurityManager.getCipher(SecurityManager.java:175)
    at securitytest.SecurityManager.decryptSecretKey(SecurityManager.java:379)
    at securitytest.SecurityManager.<init>(SecurityManager.java:82)
    at securitytest.Test.main(Test.java:44)

为了击败这个显而易见的问题，是的，我使用相同的算法：事实上，我将AES/CBC/PKCS5Padding分配给一个常量，并使用它来实例化Cipher类进行加密和解密。我还尝试仅使用AES实例化Cipher进行解密，但这也不起作用。

我要做的是使用AES / CBC / PKCS5Padding对密钥进行密码保护。我生成一个随机盐和初始化矢量。在加密密钥后，我将初始化向量（字节数组）附加到加密值（也是一个字节数组，创建一个新数组）。然后，我在Base64中对此值进行编码，并将其与salt一起存储在Sqlite数据库中（为简单起见，我将其存储为以逗号分隔的值字符串）。但是当我尝试解密时，我得到了上述异常。我可以在调用加密方法之后直接验证，并且直接在解密方法之前验证，以下值完全相同（转换为Base64以便我可以将其打印出来）：

盐
初始化向量
加密的密钥（即密文）

我尝试过Java 6和7：两者都给出了相同的结果。我还排除了无限强度管辖权政策文件的问题。事实上，如果我用另一种算法替换“AES”并相应地调整盐的长度（例如“Blowfish”，IV长度为8，产生java.security.InvalidKeyException: Wrong algorithm: Blowfish required），我会得到类似的错误。

谷歌无法帮助我解决这个问题。如果有人能够对此有所了解，我将非常感激。

以下是一些代码片段（道歉，这有点粗糙）：

private static final int INIT_VECTOR_LENGTH = 16;
private static final int PRIVATE_KEY_LENGTH = 128;
private static final int SALT_LENGTH = 16;
private static final int PBE_KEYSPEC_ITERATIONS = 65536;

private static final String CIPHER_ALGORITHM = "AES";
private static final String CIPHER_ALGORITHM_MODE = "CBC";
private static final String CIPHER_ALGORITHM_PADDING = "PKCS5Padding";
private static final String DIGEST = "SHA1";
private static final String PLAINTEXT_ENCODING = "UTF8";
private static final String PRNG = DIGEST + "PRNG";
private static final String SECRET_KEY_FACTORY = "PBKDF2WithHmac" + DIGEST;

private static final String CIPHER = CIPHER_ALGORITHM + "/" + CIPHER_ALGORITHM_MODE + "/" + CIPHER_ALGORITHM_PADDING;

private IvParameterSpec ivSpec;
private final BASE64Encoder encoder = new BASE64Encoder();
private final BASE64Decoder decoder = new BASE64Decoder();

private Cipher getCipher(SecretKey key, int mode) {

    Cipher cipher = null;

    try {
        cipher = Cipher.getInstance(CIPHER);
    }
    catch (NoSuchAlgorithmException e) {System.err.println(System.err.println(e.getMessage());}
    catch (NoSuchPaddingException e) {System.err.println(e.getMessage());}

    try {
        if (mode == Cipher.ENCRYPT_MODE) {
            cipher.init(mode, key);
            AlgorithmParameters params = cipher.getParameters();
            ivSpec = params.getParameterSpec(IvParameterSpec.class);
        }
        else {
            /* This is my point-of-failure. */
            cipher.init(mode, key, ivSpec);
        }
    }
    catch (InvalidKeyException e) {System.err.println(e.getMessage());}
    catch (InvalidAlgorithmParameterException e) {System.err.println(e.getMessage());}
    catch (InvalidParameterSpecException e) {System.err.println(e.getMessage());}

    return cipher;

}

private SecurityData.Secrets generateSecrets(SecretKey decryptedKey, byte[] salt, String passphrase) {

    /* Generate a new key for encrypting the secret key. */
    byte[] raw = null;
    PBEKey key = null;
    PBEKeySpec password = new PBEKeySpec(passphrase.toCharArray(), salt, PBE_KEYSPEC_ITERATIONS, PRIVATE_KEY_LENGTH);
    SecretKeyFactory factory = null;
    byte[] initVector = null;
    byte[] secretKeyBytes = decryptedKey.getEncoded();

    try {
        factory = SecretKeyFactory.getInstance(SECRET_KEY_FACTORY);
        key = (PBEKey) factory.generateSecret(password);
    }
    catch (NoSuchAlgorithmException e) {System.err.println(e.getMessage());}
    catch (InvalidKeySpecException e) {System.err.println(e.getMessage());}

    SecretKeySpec newKey = new SecretKeySpec(key.getEncoded(), CIPHER_ALGORITHM);

    /* Encrypt the secret key. */
    IvParameterSpec ivSpec = new IvParameterSpec(initVector);
    Cipher cipher = getCipher(newKey, ivSpec, Cipher.ENCRYPT_MODE);

    try {
        raw = cipher.doFinal(secretKeyBytes);
    }
    catch (IllegalBlockSizeException e) {System.err.println(e.getMessage());}
    catch (BadPaddingException e) {System.err.println(e.getMessage());}

    return new SecurityData.Secrets(encoder.encode(concatByteArrays(initVector, raw)), joinByteArray(salt));

}

private SecretKey decryptSecretKey(String encryptedKey, String salt, String passphrase) {

    /* Get initialisation vector. */
    byte[] raw = null, decoded = null, initVector = new byte[INIT_VECTOR_LENGTH];
    try {
        decoded = decoder.decodeBuffer(encryptedKey);
    } catch (IOException e) {System.err.println(e.getMessage());}
    System.arraycopy(decoded, 0, initVector, 0, INIT_VECTOR_LENGTH);
    raw = new byte[decoded.length-INIT_VECTOR_LENGTH];
    System.arraycopy(decoded, INIT_VECTOR_LENGTH, raw, 0, decoded.length-INIT_VECTOR_LENGTH);
    IvParameterSpec ivSpec = new IvParameterSpec(initVector);

    /* Generate the key. */
    byte[] rawSalt = splitByteArrayString(salt);
    PBEKeySpec password = new PBEKeySpec(passphrase.toCharArray(), rawSalt, PBE_KEYSPEC_ITERATIONS, PRIVATE_KEY_LENGTH);
    SecretKeyFactory factory = null;
    PBEKey key = null;
    try {
        factory = SecretKeyFactory.getInstance(SECRET_KEY_FACTORY);
        key = (PBEKey) factory.generateSecret(password);
    }
    catch (NoSuchAlgorithmException e) {System.err.println(e.getMessage());}
    catch (InvalidKeySpecException e) {System.err.println(e.getMessage());}

    Cipher cipher = getCipher(key, Cipher.DECRYPT_MODE);

    /* Decrypt the message. */
    byte[] stringBytes = null;
    try {
        stringBytes = cipher.doFinal(raw);
    }
    catch (IllegalBlockSizeException e) {System.err.println(e.getMessage());}
    catch (BadPaddingException e) {System.err.println(e.getMessage());}

    /* Converts the decoded message to a String. */
    String clear = null;
    try {
        clear = new String(stringBytes, PLAINTEXT_ENCODING);
    }
    catch (UnsupportedEncodingException e) {System.err.println(e.getMessage());}

    return new SecretKeySpec(clear.getBytes(), CIPHER_ALGORITHM);

}

Answer 1

SecretKey对象需要从其getAlgorithm()方法返回“AES”。这就是为什么这个例子有这些步骤的原因：

SecretKey tmp = factory.generateSecret(spec);
SecretKey secret = new SecretKeySpec(tmp.getEncoded(), "AES");

尝试使用Java解密时出现“错误的算法”错误

1 个答案: