Java加密:从文件加载对称密钥

时间:2015-12-22 01:29:26

标签: java encryption io symmetric-key

所以最近我开始使用加密技术。我有一个功能不对称的加密类,但我也需要一个对称的密钥类。虽然对称密钥类的大多数方面都有效,但是从它的编码字节加载密钥却不行。以下是对称密钥类。我已经标记了两个不起作用的构造函数。

public class PlasmaSymmetricEncrypter {
public static String DESEDE_ALGORITHM = "DESede";
public static String AES_ALGORITHM = "AES";

private Key key;
private String algorithm;


public PlasmaSymmetricEncrypter(Key key) {
    this.key = key;
    this.algorithm = key.getAlgorithm();
}

public PlasmaSymmetricEncrypter(File keyFile, String algorithm) throws IOException, NoSuchAlgorithmException { //This constructor is not working
    this.algorithm = algorithm;
    if(!keyFile.exists()) {
        this.genKey(keyFile);
    }

    Key key = new SecretKeySpec(Files.readAllBytes(keyFile.toPath()), algorithm);
    this.key = key;
}

public PlasmaSymmetricEncrypter(byte[] key, String algorithm) { //This constructor is not working
    this(new SecretKeySpec(key, algorithm));
}

private void genKey(File file) throws NoSuchAlgorithmException, IOException {
    KeyGenerator generator = KeyGenerator.getInstance(this.algorithm);
    this.key = generator.generateKey();
    file.delete();
    if(file.getParentFile() != null) {
        file.getParentFile().mkdirs();
    }
    file.createNewFile();
    FileOutputStream stream = new FileOutputStream(file);
    stream.write(this.getEncodedKey());
    stream.close();
}

public byte[] getEncodedKey() {
    return this.key.getEncoded();
}

public byte[] encrypt(byte[] bytes) throws BadPaddingException, IllegalBlockSizeException, InvalidKeyException, NoSuchPaddingException, NoSuchAlgorithmException {
    Cipher cipher = Cipher.getInstance(this.algorithm);
    cipher.init(Cipher.ENCRYPT_MODE, this.key);
    return cipher.doFinal(bytes);
}

public byte[] encrypt(String text) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
    return this.encrypt(text.getBytes(StandardCharsets.UTF_8));
}

public String decrypt(byte[] bytes) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
    Cipher cipher = Cipher.getInstance(this.algorithm);
    cipher.init(Cipher.DECRYPT_MODE, this.key);
    return new String(cipher.doFinal(bytes), StandardCharsets.UTF_8);
}

public String decrypt(String bytes) throws IllegalBlockSizeException, InvalidKeyException, BadPaddingException, NoSuchAlgorithmException, NoSuchPaddingException {
    return this.decrypt(bytes.getBytes(StandardCharsets.ISO_8859_1));
}

public String encryptToString(String text) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
    return new String(this.encrypt(text), StandardCharsets.ISO_8859_1);
}

}

使用以下测试代码运行会生成java.security.InvalidKeyException

    PlasmaAsymmetricEncrypter asymmetricEncrypter = new PlasmaAsymmetricEncrypter(new File("private.key"), new File("public.key"), PlasmaAsymmetricEncrypter.RSA_ALGORITHM);
    PlasmaSymmetricEncrypter symmetricEncrypter = new PlasmaSymmetricEncrypter(new File("secret.key"), PlasmaSymmetricEncrypter.AES_ALGORITHM);
    String encrypt = "hello world";
    byte[] encryptedKey = asymmetricEncrypter.encryptPrivate(symmetricEncrypter.getEncodedKey());
    PlasmaSymmetricEncrypter encrypter = new PlasmaSymmetricEncrypter(asymmetricEncrypter.decryptPublic(encryptedKey), PlasmaAsymmetricEncrypter.RSA_ALGORITHM);
    System.out.println(encrypter.decrypt(symmetricEncrypter.encrypt(encrypt)));

例外:

Exception in thread "main" java.security.InvalidKeyException: No installed provider supports this key: javax.crypto.spec.SecretKeySpec
    at javax.crypto.Cipher.chooseProvider(Cipher.java:893)
    at javax.crypto.Cipher.init(Cipher.java:1249)
    at javax.crypto.Cipher.init(Cipher.java:1186)
    at com.gmail.socraticphoenix.plasma.file.encryption.PlasmaSymmetricEncrypter.decrypt(PlasmaSymmetricEncrypter.java:96)
    at com.gmail.socraticphoenix.plasma.Test.main(Test.java:38)

测试38是System.out.println调用,PlasmaSymmetricEncrypter 96是here

我的所有代码都在github

为清晰起见编辑: 1.请忽略加密到字符串方法,一旦解决了此问题,它们将替换为base64编码。 2.构造函数本身不会发生错误,只有在我尝试获取重构密钥的密码时才会抛出该错误。

1 个答案:

答案 0 :(得分:1)

所以,我很蠢。

在我的测试代码中,我正在构建SymmetricEncrypter,如下所示:

PlasmaSymmetricEncrypter encrypter = new PlasmaSymmetricEncrypter(asymmetricEncrypter.decryptPublic(encryptedKey), PlasmaAsymmetricEncrypter.RSA_ALGORITHM);

使用RSA算法,当然这对于对称密钥不起作用。

感谢那些试图提供帮助的人,但最终我的测试代码失败了,而不是班级。