使用Java将.der转换为.pem

import java.io.*;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import org.bouncycastle.openssl.PEMWriter;

public class DERtoPEMConverter {
    public static void main(String[] args) {
        try {
            // 读取.der文件
            FileInputStream derInputStream = new FileInputStream("path/to/input.der");
            CertificateFactory certificateFactory = CertificateFactory.getInstance("X.509");
            X509Certificate certificate = (X509Certificate) certificateFactory.generateCertificate(derInputStream);

            // 将证书写入.pem文件
            FileWriter pemFileWriter = new FileWriter("path/to/output.pem");
            PEMWriter pemWriter = new PEMWriter(pemFileWriter);
            pemWriter.writeObject(certificate);
            pemWriter.close();

            System.out.println("转换成功！");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}