Java从RSA私钥中提取出 E N P Q D DP DQ QP

Alderaan

已于 2022-08-08 15:02:06 修改

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分类专栏： Java 文章标签： java 开发语言

于 2022-05-27 12:45:51 首次发布

本文链接：https://blog.youkuaiyun.com/GerZhouGengCheng/article/details/125001738

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本文介绍了一种从PKCS8格式的RSA私钥中提取公钥及其它关键参数的方法，并展示了如何使用Java标准库完成这一过程。

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import java.util.Base64;
import java.math.BigInteger;
import java.security.KeyFactory;
import java.security.PublicKey;
import java.security.interfaces.RSAPrivateCrtKey;
import java.security.interfaces.RSAPrivateKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.RSAPrivateKeySpec;
import java.security.spec.RSAPublicKeySpec;

/**
 * RSA提取组成元素类
 * 
 * @author alderaan
 * @version 创建时间：2022年5月27日 下午12:36:21
 *
 */
public class RSAComponent
{
	// X509 公钥
	private static String publicKeyStr = "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAvFyBNSJuXtlpkkDgBChl" + 
			"TwY0WBl9c3DjWf3QQ+UdWfLQ0mR92ZNV2IY+yEZ4KMZvW/nH98hFm40W0K5NY1G7" + 
			"zCbDbPKjjk81sx/Ec5ms8b3htqU81pBNM68SGz2w7IfCWiJc3fMUGg5kQYOFCP+A" + 
			"DHAHf7YEOp8OpErq0LrtYWR4Pzq6RvKvZAYvhkGm7AR/hadEluMdIhWwIkdXoPr/" + 
			"0JNL6Ay50/7GyjGTCuvCpvvVLn9MpgyeLtF8cnGAnENsBSNhxT/iC19rAJ9nzuoR" + 
			"4tufZQxSHb/2mW0Rc19t52N1YRkU6RvD8lxVp/Q4CtQf8sPy5dUtb6gzSQ9cRA5S" + 
			"lQIDAQAB";
	
	// PKCS8 私钥
	private static String privateKeyStr = "MIIEvgIBADANBgkqhkiG9w0BAQEFAASCBKgwggSkAgEAAoIBAQC8XIE1Im5e2WmS" + 
			"QOAEKGVPBjRYGX1zcONZ/dBD5R1Z8tDSZH3Zk1XYhj7IRngoxm9b+cf3yEWbjRbQ" + 
			"rk1jUbvMJsNs8qOOTzWzH8RzmazxveG2pTzWkE0zrxIbPbDsh8JaIlzd8xQaDmRB" + 
			"g4UI/4AMcAd/tgQ6nw6kSurQuu1hZHg/OrpG8q9kBi+GQabsBH+Fp0SW4x0iFbAi" + 
			"R1eg+v/Qk0voDLnT/sbKMZMK68Km+9Uuf0ymDJ4u0XxycYCcQ2wFI2HFP+ILX2sA" + 
			"n2fO6hHi259lDFIdv/aZbRFzX23nY3VhGRTpG8PyXFWn9DgK1B/yw/Ll1S1vqDNJ" + 
			"D1xEDlKVAgMBAAECggEAGIxBtogHNEtHS+0yhLgzA8p+NeEUjV/v8UF3y/FnEtrn" + 
			"RhQcpqdh77cHJZixfjbmOmliGzO5hp0rlQSyRzhWrjN7Eo7Iq/o8uFxygNJNTK//" + 
			"Y4tDU3844Hx3cp9mmFzVAmQqEC7mtsKbZEJcqyCJMpXDFGzHPlCOWvD8izlhSGjT" + 
			"N+z3qwBTaQLym9VG2GqohzVbW0wwryFPMhWOHHCiejamhmERNRBGtzwBOoPiMyzx" + 
			"/BbLgsO9T90qL/zNEEU+vrja/Wq/V84akwRysUyoJvFI6uhLED79t3odzg+cvDZV" + 
			"66TEyuKemnjQcusqulVKBuXJDLsZWronrXN9X0tBIQKBgQDrLuSvOz3rFqQWuEhc" + 
			"uZaJcFY2iFwXtHUjBGi5mWJBRVAxJlrC1Erdky79gNCsZiZrz58x/2tS1IHAUdUJ" + 
			"qPsSF1X17dT4ZIcHXd6a8eLmamNFoomR7VtcJ1gOwt+YOe3FSmANKLc63DPnZaJM" + 
			"QrWYSGGz7rp26tVQXtZv86cjHQKBgQDNCKhNKtF/p2GwS4jPfxXm679WwHYOlyPa" + 
			"fs9a64yq6orthsAYNIA2zMORHite76mGtpVNpfaQwJhjV7O445FGejVRCZII5afK" + 
			"np29jgIuRSSj2PRKI5AYaI4+PZmeHN4Uf8mm+paLwFzLyHYE6gSur1W/ryJxhqq1" + 
			"2OSVjGub2QKBgQCuPgjqFt8yDI031AKwyENSwmrtbiuk2GssrXiVgaF9MEhQkdUO" + 
			"odBxxzk6UjTIdcojeCi/FzjBnnYfMcG/rXWOmsFyOmneOkScXZyueWWdRtcT4W9B" + 
			"MXTNmsyv6wtTsh+KWyc8uJzAPCMsXm1XSNlX4NCaSdXWgvfV2t3PBdsftQKBgGJR" + 
			"HnMybxcpajyhW88z/4qlzTCKRZIlg3nIiSHuBZwHr+rKTN7OfhTJB5ZUwzNY9Q+2" + 
			"Cc4cISm0UN6CNZoY9Za4D0z2q+I8TcNpX/Z/XChX24P+CtZqSzSJHnxWCY26BfwK" + 
			"cuXxD7Of4F+Plpgwp2IkjZfHIVsS2lUs1h+oIAmxAoGBAKwPruU4J4ir23kw6joG" + 
			"RJ9wMzEvsis6wErMfZP0YjHGm5gD4l3gPEhv6Z6FQCgsKCPeo1QRr2xOMRdR3qbz" + 
			"OsvtbU4l0cjitkQJT2geiWkIs8n+QlCzxV/XJMe1kKysdu0yJr3GtCqsCaFv9+9i" + 
			"xhcjT63ir4OgV9Bdf/geRMYh";

	public static void main(String[] args) throws Exception
	{
		byte[] decodedprivate = Base64.getDecoder().decode(privateKeyStr);
		RSAPrivateKey priKey = (RSAPrivateKey) KeyFactory.getInstance("RSA")
				.generatePrivate(new PKCS8EncodedKeySpec(decodedprivate));

		// 从私钥中提取公钥
		KeyFactory kf = KeyFactory.getInstance("RSA");
		RSAPrivateKeySpec priv = kf.getKeySpec(priKey, RSAPrivateKeySpec.class);

		RSAPublicKeySpec keySpec = new RSAPublicKeySpec(priv.getModulus(), BigInteger.valueOf(65537));

		PublicKey publicKey = kf.generatePublic(keySpec);
		// 对公钥进行Base64编码
		String publickeystr_new = Base64.getEncoder().encodeToString(publicKey.getEncoded());

		// 提取后的公钥与成对生成的公钥进行比较
		if (0 == publicKeyStr.compareTo(publickeystr_new))
		{
			System.out.println("提取的公钥校验一致！\n公钥Base64字符串为：\n" + publicKeyStr + "\n");
		}

		RSAPrivateCrtKey rsaPrivateKey = (RSAPrivateCrtKey) priKey;

		String p = rsaPrivateKey.getPrimeP().toString(16).toUpperCase();
		String q = rsaPrivateKey.getPrimeQ().toString(16).toUpperCase();
		String d = rsaPrivateKey.getPrivateExponent().toString(16).toUpperCase();
		String dp = rsaPrivateKey.getPrimeExponentP().toString(16).toUpperCase();
		String dq = rsaPrivateKey.getPrimeExponentQ().toString(16).toUpperCase();
		String qp = rsaPrivateKey.getCrtCoefficient().toString(16).toUpperCase();
		String e = rsaPrivateKey.getPublicExponent().toString(16).toUpperCase();
		String n = rsaPrivateKey.getModulus().toString(16).toUpperCase();

		System.out.println("P:\n" + p + "\n");
		System.out.println("Q:\n" + q + "\n");
		System.out.println("D:\n" + d + "\n");
		System.out.println("DP:\n" + dp + "\n");
		System.out.println("DQ:\n" + dq + "\n");
		System.out.println("QP:\n" + qp + "\n");
		System.out.println("E:\n" + e + "\n");
		System.out.println("N:\n" + n + "\n");
	}
}