如何用java读取密码加密密钥？

Question

我的私钥以 PKCS8 DER 格式存储在文件中，并受密码保护。最简单的阅读方法是什么？

这是我用来加载未加密密钥的代码：

InputStream in = new FileInputStream(privateKeyFilename);
byte[] privateKeydata = new byte[in.available()];
in.read(privateKeydata);
in.close();
KeyFactory privateKeyFactory = KeyFactory.getInstance("RSA");
PKCS8EncodedKeySpec encodedKeySpec = new PKCS8EncodedKeySpec(privateKeydata);
PrivateKey privateKey = privateKeyFactory.generatePrivate(encodedKeySpec);

对于具有相同规格的未加密密钥，它工作得很好。顺便说一句，我正在使用 BouncyCastle。

我可以使用以下 openssl 命令查看此私钥

openssl pkcs8 -in ./privatekey.key -inform DER -passin pass:thisismypass

请帮忙！！！

我在自己对此主题的回答中发布了一些解决方案。但我没有回答问题，以防有人可以帮助使其在没有额外库（只需 BouncyCastle）的情况下工作。

Answer 1

我找到了解决方案！也许它不是那么优雅，但是......
在这里我将发布两个解决方案：

1. 首选，但不起作用
2. 工作一个，但需要额外的库

第一个：

我找到了一种解决方案 这里，但它抛出异常。解决方案：

import java.io.*;
import java.security.*;
import java.security.interfaces.RSAPrivateCrtKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.*;

import javax.crypto.*;
import javax.crypto.spec.*;

/*
 * This class demonstrates how to import an encrypted RSA private key as
 * generated by openssl. The input file is presumed to be in DER
 * format.
 */
public class ImportEncryptedPrivateKey
{
    public static byte[] readPK8FromFile(String fileName) throws IOException
    {
        File f = new File(fileName);
        DataInputStream dis = new DataInputStream(new FileInputStream(f));
        byte[] theData = new byte[(int) f.length()];
        dis.readFully(theData);
        return theData;
    }

    public static void main(String[] args) throws IOException,
            NoSuchAlgorithmException, NoSuchPaddingException,
            InvalidKeySpecException, InvalidKeyException,
            InvalidAlgorithmParameterException
    {
        byte[] encryptedPKInfo = readPK8FromFile("rsapriv.pk8");
        EncryptedPrivateKeyInfo ePKInfo = new EncryptedPrivateKeyInfo(
                encryptedPKInfo);
        char[] password = { 'p', 'a', 's', 's', 'w', 'o', 'r', 'd' };
        Cipher cipher = Cipher.getInstance(ePKInfo.getAlgName());
        PBEKeySpec pbeKeySpec = new PBEKeySpec(password);
        // Now create the Key from the PBEKeySpec
        SecretKeyFactory skFac = SecretKeyFactory.getInstance(ePKInfo
                .getAlgName());
        Key pbeKey = skFac.generateSecret(pbeKeySpec);
        // Extract the iteration count and the salt
        AlgorithmParameters algParams = ePKInfo.getAlgParameters();
        cipher.init(Cipher.DECRYPT_MODE, pbeKey, algParams);
        // Decrypt the encryped private key into a PKCS8EncodedKeySpec
        KeySpec pkcs8KeySpec = ePKInfo.getKeySpec(cipher);
        // Now retrieve the RSA Public and private keys by using an
        // RSA keyfactory.
        KeyFactory rsaKeyFac = KeyFactory.getInstance("RSA");
        // First get the private key
        RSAPrivateCrtKey rsaPriv = (RSAPrivateCrtKey) rsaKeyFac.generatePrivate(pkcs8KeySpec);
        // Now derive the RSA public key from the private key
        RSAPublicKeySpec rsaPubKeySpec = new RSAPublicKeySpec(rsaPriv.getModulus(), rsaPriv.getPublicExponent());
        RSAPublicKey rsaPubKey = (RSAPublicKey) rsaKeyFac.generatePublic(rsaPubKeySpec);
    }

}

我的例外：

Exception in thread "main" java.security.NoSuchAlgorithmException: No such algorithm: 1.2.840.113549.1.5.13

第二：

按照此http://juliusdavies.ca/commons-ssl/pkcs8.html 您可以阅读第二个可行的解决方案

Answer 2

这是我的代码，它可以工作：）

File f = new File(keyFile);
FileInputStream fis = new FileInputStream(f);
DataInputStream dis = new DataInputStream(fis);
byte[] keyBytes = new byte[(int)f.length()];
dis.readFully(keyBytes);
dis.close();
EncryptedPrivateKeyInfo encryptPKInfo = new EncryptedPrivateKeyInfo(keyBytes);
Cipher cipher = Cipher.getInstance(encryptPKInfo.getAlgName());
PBEKeySpec pbeKeySpec = new PBEKeySpec(passwd.toCharArray());
SecretKeyFactory secFac = SecretKeyFactory.getInstance(encryptPKInfo.getAlgName());
Key pbeKey = secFac.generateSecret(pbeKeySpec);
AlgorithmParameters algParams = encryptPKInfo.getAlgParameters();
cipher.init(Cipher.DECRYPT_MODE, pbeKey, algParams);
KeySpec pkcs8KeySpec = encryptPKInfo.getKeySpec(cipher);
KeyFactory kf = KeyFactory.getInstance("RSA");
return kf.generatePrivate(pkcs8KeySpec);