Question

我想在Android Keystore中生成RSA密钥对。由于Android 4.3应该可以在Android系统Keystore中生成RSA密钥。

我生成我的RSA密钥（工作正常）

        Calendar notBefore = Calendar.getInstance();
        Calendar notAfter = Calendar.getInstance();
        notAfter.add(1, Calendar.YEAR);
        KeyPairGeneratorSpec spec = new KeyPairGeneratorSpec.Builder(ctx)
                .setAlias("key")
                .setSubject(
                        new X500Principal(String.format("CN=%s, OU=%s",
                                "key", ctx.getPackageName())))
                .setSerialNumber(BigInteger.ONE)
                .setStartDate(notBefore.getTime())
                .setEndDate(notAfter.getTime()).build();
            KeyPairGenerator kpg;
            kpg = KeyPairGenerator.getInstance("RSA", "AndroidKeyStore");
            kpg.initialize(spec);
            KeyPair kp = kpg.genKeyPair();
            publicKey = kp.getPublic();
            privateKey = kp.getPrivate();

我的RSA加密看起来像（也适用）：

    public static byte[] RSAEncrypt(final byte[] plain)
        throws NoSuchAlgorithmException, NoSuchPaddingException,
        InvalidKeyException, IllegalBlockSizeException, BadPaddingException {

    Cipher cipher = Cipher.getInstance("RSA");
    System.out.println("RSA Encryption key: " + publicKey.getAlgorithm());
    System.out.println("RSA Encryption key: " + publicKey.getEncoded());

    cipher.init(Cipher.ENCRYPT_MODE, publicKey);
    byte[] encryptedBytes = cipher.doFinal(plain);
    return encryptedBytes;
}

解密：

    public static byte[] RSADecrypt(final byte[] encryptedBytes)
        throws NoSuchAlgorithmException, NoSuchPaddingException,
        InvalidKeyException, IllegalBlockSizeException, BadPaddingException {

    Cipher cipher1 = Cipher.getInstance("RSA");

    System.out.println("RSA Encryption key: " + privateKey.getAlgorithm());
    System.out.println("RSA Encryption key: " + privateKey.getEncoded());

    cipher1.init(Cipher.DECRYPT_MODE, privateKey);
    byte[] decryptedBytes = cipher1.doFinal(encryptedBytes);
    return decryptedBytes;
}

在解密函数中，我收到以下错误消息（当privateKey被编码时，在cipher1.init（）中）：

12-12 21:49:40.338: E/AndroidRuntime(20423): FATAL EXCEPTION: main
12-12 21:49:40.338: E/AndroidRuntime(20423): java.lang.UnsupportedOperationException: private    exponent cannot be extracted
12-12 21:49:40.338: E/AndroidRuntime(20423):    at org.apache.harmony.xnet.provider.jsse.OpenSSLRSAPrivateKey.getPrivateExponent(OpenSSLRSAPrivateKey.java:143)

我不明白。是否无法在Android KeyStore中生成RSA密钥？任何人都可以向我提供在Android KeyStore中生成RSA密钥并使用私钥解密的示例。

非常感谢提前！

Answer 1

根据the code，我认为OpenSSL提供程序可以防止在将密钥生成到设备中时导出私有指数。

@Override
public final BigInteger getPrivateExponent() {
    if (key.isEngineBased()) {
        throw new UnsupportedOperationException("private exponent cannot be extracted");
    }

    ensureReadParams();
    return privateExponent;
}

因此，您可能需要在检索密码实例时指定要使用相同的加密提供程序。此提供商supports these RSA ciphers：

RSA / ECB / NoPadding
RSA / ECB / PKCS1Padding

您应该以这种方式创建密码实例：

Cipher cipher1 = Cipher.getInstance("RSA/ECB/PKCS1Padding", "AndroidOpenSSL");

无法提取Android KeyStore私有指数

1 个答案: