详细用java实现jks文件和jwks文件的互相转换

JKS（Java KeyStore）文件是一种Java密钥库，用于存储密钥和证书，而JWKS（JSON Web Key Set）文件是一种用于描述一组公共密钥的JSON格式。

下面是Java代码实现JKS文件和JWKS文件的互相转换：

1. 将JKS文件转换为JWKS文件：

import java.io.FileInputStream;
import java.security.Key;
import java.security.KeyStore;
import java.security.cert.Certificate;
import java.util.ArrayList;
import java.util.List;
import org.json.JSONArray;
import org.json.JSONObject;

public class JksToJwksConverter {

    public static void main(String[] args) throws Exception {
        String jksFile = "path/to/your/jks/file";
        String jksPassword = "your_jks_password";
        String jksAlias = "your_key_alias";

        KeyStore keyStore = KeyStore.getInstance("JKS");
        FileInputStream fis = new FileInputStream(jksFile);
        keyStore.load(fis, jksPassword.toCharArray());

        Key key = keyStore.getKey(jksAlias, jksPassword.toCharArray());
        if (key != null) {
            Certificate cert = keyStore.getCertificate(jksAlias);

            JSONObject jwks = new JSONObject();
            jwks.put("keys", new JSONArray());

            JSONObject jwk = new JSONObject();
            jwk.put("kty", "RSA"); // or "EC" for ECDSA keys
            jwk.put("use", "sig"); // or "enc" for encryption keys
            jwk.put("kid", jksAlias);

            // get public key from private key
            String publicKey = Base64.getEncoder().encodeToString(cert.getPublicKey().getEncoded());
            jwk.put("n", publicKey);

            JSONArray keys = jwks.getJSONArray("keys");
            keys.put(jwk);

            System.out.println(jwks.toString(4));
        }
    }
}

2. 将JWKS文件转换为JKS文件：

import java.io.FileOutputStream;
import java.math.BigInteger;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.KeyStore;
import java.security.PrivateKey;
import java.security.cert.Certificate;
import java.security.cert.X509Certificate;
import java.security.spec.RSAPublicKeySpec;
import java.util.Date;

import javax.security.auth.x500.X500Principal;

import org.bouncycastle.asn1.x500.X500Name;
import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo;
import org.bouncycastle.cert.X509CertificateHolder;
import org.bouncycastle.cert.jcajce.JcaX509CertificateConverter;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.openssl.jcajce.JcaPEMWriter;
import org.bouncycastle.util.io.pem.PemObject;

public class JwksToJksConverter {

    public static void main(String[] args) throws Exception {
        String jwksFile = "path/to/your/jwks/file";
        String jksFile = "path/to/your/jks/file";
        String jksPassword = "your_jks_password";
        String jksAlias = "your_key_alias";

        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
        keyPairGenerator.initialize(2048);
        KeyPair keyPair = keyPairGenerator.generateKeyPair();

        // create X509 certificate
        X500Name subject = new X500Name("CN=example.com");
        BigInteger serial = BigInteger.valueOf(System.currentTimeMillis());
        Date notBefore = new Date(System.currentTimeMillis() - 1000L * 3600 * 24 * 30);
        Date notAfter = new Date(System.currentTimeMillis() + 1000L * 3600 * 24 * 365);
        X509CertificateHolder certHolder = new X509CertificateHolder(
                SubjectPublicKeyInfo.getInstance(keyPair.getPublic().getEncoded()),
                subject, serial, notBefore, notAfter, subject);
        X509Certificate cert = new JcaX509CertificateConverter().setProvider(new BouncyCastleProvider())
                .getCertificate(certHolder);

        // create JKS keystore
        KeyStore keyStore = KeyStore.getInstance("JKS");
        keyStore.load(null, jksPassword.toCharArray());
        keyStore.setKeyEntry(jksAlias, keyPair.getPrivate(), jksPassword.toCharArray(), new Certificate[] { cert });

        FileOutputStream fos = new FileOutputStream(jksFile);
        keyStore.store(fos, jksPassword.toCharArray());
        fos.close();
    }
}

注意：上述代码需要引入Bouncy Castle库，可以通过Maven或Gradle添加依赖：

Maven:

<dependency>
    <groupId>org.bouncycastle</groupId>
    <artifactId>bcprov-jdk15on</artifactId>
    <version>1.69</version>
</dependency>
<dependency>
    <groupId>org.bouncycastle</groupId>
    <artifactId>bcpkix-jdk15on</artifactId>
    <version>1.69</version>
</dependency>

Gradle：

implementation 'org.bouncycastle:bcprov-jdk15on:1.69'
implementation 'org.bouncycastle:bcpkix-jdk15on:1.69'