使用 Bouncy Castle 重建私钥和 public 密钥？

Question

如果我使用 getEncoded 从 Java 中的 public 或 Bouncy Castle 中的私钥获得实际密钥（实际 class 似乎是 BCECPublicKey 和 BCECPrivateKey）。是否可以重建关键对象以在代码中使用它们？

我在 Stack Overflow 中发现了如何将整个对象序列化为二进制（然后到磁盘），然后返回二进制和适当 class 的对象，但我相信序列化包含实现细节，如果我尝试将这些键与 Bouncy Castle 以外的任何东西一起使用，它将失败。我现在不想这样做，但我想让我的程序面向未来。

这就是我创建密钥的方式：

    KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("EC", "BC");
    keyPairGenerator.initialize(new ECGenParameterSpec("secp521r1"), new SecureRandom());
    java.security.KeyPair keyPair = keyPairGenerator.generateKeyPair();

    privateKey = keyPair.getPrivate();
    publicKey = keyPair.getPublic();

Answer 1

键上的KeyFactory is used to convert between encoded keys and the Java classes that represent them. However, the KeyFactory instance doesn't convert directly between a byte array and a Key class. Instead, you must already know what format the encoding uses, and then create a KeySpec object using the byte array in the constructor. The format can be determined by called the getFormat()方法。这是一个说明其中一些要点的示例。

import org.bouncycastle.jce.provider.BouncyCastleProvider;

import java.security.*;
import java.security.spec.ECGenParameterSpec;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

public class Main {

    public static void main(String[] args) throws Exception{
        Security.addProvider(new BouncyCastleProvider());
        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("EC", "BC");
        keyPairGenerator.initialize(new ECGenParameterSpec("secp521r1"), new SecureRandom());
        java.security.KeyPair keyPair = keyPairGenerator.generateKeyPair();

        PrivateKey privateKey = keyPair.getPrivate();
        System.out.println(privateKey.getFormat());
        PublicKey publicKey = keyPair.getPublic();
        System.out.println(publicKey.getFormat());

        // A KeyFactory is used to convert encoded keys to their actual Java classes
        KeyFactory ecKeyFac = KeyFactory.getInstance("EC", "BC");

        // Now do a round-trip for a private key,
        byte [] encodedPriv = privateKey.getEncoded();
        // now take the encoded value and recreate the private key
        PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(encodedPriv);
        PrivateKey privateKey2 = ecKeyFac.generatePrivate(pkcs8EncodedKeySpec);

        // And a round trip for the public key as well.
        byte [] encodedPub = publicKey.getEncoded();
        X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(encodedPub);
        PublicKey publicKey2 = ecKeyFac.generatePublic(x509EncodedKeySpec);
        System.out.println(publicKey2);

    }
}

使用 Bouncy Castle 重建私钥和 public 密钥？

Reconstructing private and public keys with Bouncy Castle?

java

bouncycastle