如何在JAVA中生成RSA密钥对（openssl格式）

Question

如何使用 OpenSSL 支持的格式在 Java 中生成 RSA 密钥对？

换句话说，我如何使用Java来实现

openssl

中的内容？

openssl genrsa -out mykey.pem 1024

---

输出应该是这样的：

    -----BEGIN PUBLIC KEY-----
   MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA3Qa9WiabsxGv2uJBNNFn
   Ai3vEDF7Evr85RlgrviUSzkSupEH29PaazKX04/4M7mEQswVZOHSzkFRXiviImi1
   c1UrWlZENctS3A6P3RSqOonzrw6CVDJ4Nn/iydWlHhFaHBPpCopS537iHvJIey7K
   -----END PUBLIC KEY-----

   -----BEGIN PRIVATE KEY-----
   MIIEvAIBADANBgkqhkiG9w0BAQEFAASCBKYwggSiAgEAAoIBAQDdBr1aJpuzEa/a
   4kE00WcCLe8QMXsS+vzlGWCu+JRLORK6kQfb09prMpfTj/gzuYRCzBVk4dLOQVFe
   K+IiaLVzVStaVkQ1y1LcDo/dFKo6ifOvDoJUMng2f+LJ1aUeEVocE+kKilLnfuIe
   8kh7LsplosEQSxpfhjQcxt6qgRQk+eI9kyxczLvt2S0goAoO7rPIhi1LQFI1uUij
   U18a+vsu9uv/mMAa/R101EZxIJyZZDtjyajPUP3Zo7LfxXZpVgg8xXAE6xY3PGlJ

   -----END PRIVATE KEY-----

Answer 1

您说的是 OpenSSL 支持的“该”格式，但 OpenSSL 支持（RSA 和其他）私钥的多种格式，根据您的计数方式，有十多种格式。

您显示的特定格式（也许是巧合）是Java加密直接支持的两种格式的PEM形式，私有的PKCS8未加密和公共的“X.509”（实际上是SubjectPublicKeyInfo，又名SPKI），因此可以创建简单：

//nopackage
import java.security.*;
import java.util.Base64;

public class SO43459993SimpleRSAPEM {
    public static void main (String[] args) throws Exception {
        KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA");
        kpg.initialize(2048); KeyPair kp = kpg.generateKeyPair();

        System.out.println ("-----BEGIN PRIVATE KEY-----");
        System.out.println (Base64.getMimeEncoder().encodeToString( kp.getPrivate().getEncoded()));
        System.out.println ("-----END PRIVATE KEY-----");
        System.out.println ("-----BEGIN PUBLIC KEY-----");
        System.out.println (Base64.getMimeEncoder().encodeToString( kp.getPublic().getEncoded()));
        System.out.println ("-----END PUBLIC KEY-----");

    }
}

输出示例：

-----BEGIN PRIVATE KEY-----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-----END PRIVATE KEY-----
-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAomk/8wcY0umQYgm1AYlBYq5t/8aPgPC2
N8gbH37uv+pjtGcK1zbax5qUBHZXef1zPpPLyjhPik33lMIpCji5x3rs1eaqzuP1mTw8s4IFxqha
4CN/1k/AKk3AJnNtQhvdlsfqJlWhcpeY+f0oemmqWJekxu6l+DV8xJZ+ymu9AM9/ZyraoqHuywOQ
EY3MjgUT11YNjqvzvl0sMv3qRRyLPN7nLMBdY/+Db+Lu47giEOPrEBcgVMIdnaHIB/fi7DENfGtj
d5ITW4cQ/U5HobkhlPvyh3dDphF1R8encRL71UxvjGLrqgW1MXZ0XoIE3V+WyVF7c3/kTPusrqmr
izZSQwIDAQAB
-----END PUBLIC KEY-----