java-信息安全（十一）-非對稱加密算法ECC

時間 2019-11-29

標籤 java 信息安全十一非對稱加密算法 ecc 欄目 Java 简体版

原文原文鏈接

概述

信息安全基本概念：java

ECC算法（Elliptic curve cryptography，橢圓曲線密碼學）

ECC

　　橢圓加密算法（ECC）是一種公鑰加密體制，最初由Koblitz和Miller兩人於1985年提出，其數學基礎是利用橢圓曲線上的有理點構成Abel加法羣上橢圓離散對數的計算困難性。算法

　　是目前已知的公鑰體制中，對每比特所提供加密強度最高的一種體制。在軟件註冊保護方面起到很大的做用，通常的序列號一般由該算法產生。apache

　　ECC算法在jdk1.5後加入支持，目前僅僅只能完成密鑰的生成與解析。若是想要得到ECC算法實現，須要調用硬件完成加密/解密（ECC算法至關耗費資源，若是單純使用CPU進行加密/解密，效率低下）.安全

算法分類信息：

算法	密鑰長度	默認長度	簽名長度	實現的方
NONEwithECDSA	112-571	256	128	JDK/BC
RIPEMD160withECDSA	同上	256	160	BC
SHA1withECDSA	...	256	160	JDK/BC
SHA224withECDSA	...	256	224	BC
SHA256withECDSA	...	256	256	JDK/BC
SHA384withECDSA	...	256	384	JDK/BC
SHA512withECDSA	...	256	512	JDK/BC

簽名示例

import java.security.KeyFactory;  
import java.security.KeyPair;  
import java.security.KeyPairGenerator;  
import java.security.PrivateKey;  
import java.security.PublicKey;  
import java.security.Signature;  
import java.security.interfaces.ECPrivateKey;  
import java.security.interfaces.ECPublicKey;  
import java.security.spec.PKCS8EncodedKeySpec;  
import java.security.spec.X509EncodedKeySpec;  
  
import com.sun.org.apache.xerces.internal.impl.dv.util.HexBin;  
  
public class ECDSA {  
    private static String src = "ecdsa security";  
    public static void main(String[] args) {  
        jdkECDSA();  
    }  
      
    public static void jdkECDSA(){  
        try {  
            //1.初始化密鑰   
            KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("EC");  
            keyPairGenerator.initialize(256);  
            KeyPair keyPair = keyPairGenerator.generateKeyPair();  
            ECPublicKey ecPublicKey = (ECPublicKey)keyPair.getPublic();  
            ECPrivateKey ecPrivateKey = (ECPrivateKey)keyPair.getPrivate();  
              
              
            //2.執行簽名  
            PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(ecPrivateKey.getEncoded());  
              
            KeyFactory keyFactory = KeyFactory.getInstance("EC");  
            PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);  
            Signature signature = Signature.getInstance("SHA1withECDSA");  
            signature.initSign(privateKey);  
            signature.update(src.getBytes());  
            byte[] res = signature.sign();  
            System.out.println("簽名："+HexBin.encode(res));  
              
            //3.驗證簽名  
            X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(ecPublicKey.getEncoded());  
            keyFactory = KeyFactory.getInstance("EC");  
            PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);  
            signature = Signature.getInstance("SHA1withECDSA");  
            signature.initVerify(publicKey);  
            signature.update(src.getBytes());  
            boolean bool = signature.verify(res);  
            System.out.println("驗證："+bool);  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
    }  
  
}

加解密示例代碼ide

package com.jd.order.util.encryption;

import java.math.BigInteger;
import java.security.Key;
import java.security.KeyFactory;
import java.security.interfaces.ECPrivateKey;
import java.security.interfaces.ECPublicKey;
import java.security.spec.ECFieldF2m;
import java.security.spec.ECParameterSpec;
import java.security.spec.ECPoint;
import java.security.spec.ECPrivateKeySpec;
import java.security.spec.ECPublicKeySpec;
import java.security.spec.EllipticCurve;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;

import javax.crypto.Cipher;
import javax.crypto.NullCipher;

import org.apache.commons.codec.binary.Base64;

import sun.security.ec.ECKeyFactory;
import sun.security.ec.ECPrivateKeyImpl;
import sun.security.ec.ECPublicKeyImpl;

@SuppressWarnings("restriction")
public class ECCCoder {
    public static final String ALGORITHM = "EC";
    private static final String PUBLIC_KEY = "ECCPublicKey";
    private static final String PRIVATE_KEY = "ECCPrivateKey";

    /**
     * 解密<br>
     * 用私鑰解密
     * 
     * @param data
     * @param key
     * @return
     * @throws Exception
     */
    public static byte[] decrypt(byte[] data, String key) throws Exception {
        // 對密鑰解密
        byte[] keyBytes = decryptBASE64(key);

        // 取得私鑰
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = ECKeyFactory.INSTANCE;

        ECPrivateKey priKey = (ECPrivateKey) keyFactory
                .generatePrivate(pkcs8KeySpec);

        ECPrivateKeySpec ecPrivateKeySpec = new ECPrivateKeySpec(priKey.getS(),
                priKey.getParams());

        // 對數據解密
        // TODO Chipher不支持EC算法 未能實現
        Cipher cipher = new NullCipher();
        // Cipher.getInstance(ALGORITHM, keyFactory.getProvider());
        cipher.init(Cipher.DECRYPT_MODE, priKey, ecPrivateKeySpec.getParams());

        return cipher.doFinal(data);
    }

    /**
     * 加密<br>
     * 用公鑰加密
     * 
     * @param data
     * @param privateKey
     * @return
     * @throws Exception
     */
    public static byte[] encrypt(byte[] data, String privateKey)
            throws Exception {
        // 對公鑰解密
        byte[] keyBytes = decryptBASE64(privateKey);

        // 取得公鑰
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = ECKeyFactory.INSTANCE;

        ECPublicKey pubKey = (ECPublicKey) keyFactory
                .generatePublic(x509KeySpec);

        ECPublicKeySpec ecPublicKeySpec = new ECPublicKeySpec(pubKey.getW(),
                pubKey.getParams());

        // 對數據加密
        // TODO Chipher不支持EC算法 未能實現
        Cipher cipher = new NullCipher();
        // Cipher.getInstance(ALGORITHM, keyFactory.getProvider());
        cipher.init(Cipher.ENCRYPT_MODE, pubKey, ecPublicKeySpec.getParams());

        return cipher.doFinal(data);
    }

    /**
     * 取得私鑰
     * 
     * @param keyMap
     * @return
     * @throws Exception
     */
    public static String getPrivateKey(Map<String, Object> keyMap)
            throws Exception {
        Key key = (Key) keyMap.get(PRIVATE_KEY);

        return encryptBASE64(key.getEncoded());
    }

    /**
     * 取得公鑰
     * 
     * @param keyMap
     * @return
     * @throws Exception
     */
    public static String getPublicKey(Map<String, Object> keyMap)
            throws Exception {
        Key key = (Key) keyMap.get(PUBLIC_KEY);

        return encryptBASE64(key.getEncoded());
    }

    /**
     * 初始化密鑰
     * 
     * @return
     * @throws Exception
     */
    public static Map<String, Object> initKey() throws Exception {
        BigInteger x1 = new BigInteger(
                "2fe13c0537bbc11acaa07d793de4e6d5e5c94eee8", 16);
        BigInteger x2 = new BigInteger(
                "289070fb05d38ff58321f2e800536d538ccdaa3d9", 16);

        ECPoint g = new ECPoint(x1, x2);

        // the order of generator
        BigInteger n = new BigInteger(
                "5846006549323611672814741753598448348329118574063", 10);
        // the cofactor
        int h = 2;
        int m = 163;
        int[] ks = { 7, 6, 3 };
        ECFieldF2m ecField = new ECFieldF2m(m, ks);
        // y^2+xy=x^3+x^2+1
        BigInteger a = new BigInteger("1", 2);
        BigInteger b = new BigInteger("1", 2);

        EllipticCurve ellipticCurve = new EllipticCurve(ecField, a, b);

        ECParameterSpec ecParameterSpec = new ECParameterSpec(ellipticCurve, g,
                n, h);
        // 公鑰
        ECPublicKey publicKey = new ECPublicKeyImpl(g, ecParameterSpec);

        BigInteger s = new BigInteger(
                "1234006549323611672814741753598448348329118574063", 10);
        // 私鑰
        ECPrivateKey privateKey = new ECPrivateKeyImpl(s, ecParameterSpec);

        Map<String, Object> keyMap = new HashMap<String, Object>(2);

        keyMap.put(PUBLIC_KEY, publicKey);
        keyMap.put(PRIVATE_KEY, privateKey);

        return keyMap;
    }

    public static byte[] decryptBASE64(String data) {
        return Base64.decodeBase64(data);
    }

    public static String encryptBASE64(byte[] data) {
        return new String(Base64.encodeBase64(data));
    }
}

請注意上述代碼中的TODO內容，再次提醒注意，Chipher不支持EC算法，以上代碼僅供參考。Chipher、Signature、KeyPairGenerator、KeyAgreement、SecretKey均不支持EC算法。爲了確保程序可以正常執行，咱們使用了NullCipher類，驗證程序。測試

測試示例加密

package com.jd.order.util.encryption;

import static org.junit.Assert.assertEquals;

import java.util.Map;

import org.junit.Test;

public class ECCCoderTest {

    @Test
    public void test() throws Exception {
        String inputStr = "abc";
        byte[] data = inputStr.getBytes();

        Map<String, Object> keyMap = ECCCoder.initKey();

        String publicKey = ECCCoder.getPublicKey(keyMap);
        String privateKey = ECCCoder.getPrivateKey(keyMap);
        System.err.println("公鑰: \n" + publicKey);
        System.err.println("私鑰： \n" + privateKey);

        byte[] encodedData = ECCCoder.encrypt(data, publicKey);

        byte[] decodedData = ECCCoder.decrypt(encodedData, privateKey);

        String outputStr = new String(decodedData);
        System.err.println("加密前: " + inputStr + "\n\r" + "解密後: " + outputStr);
        assertEquals(inputStr, outputStr);
    }

}

輸出spa

公鑰: 
MEAwEAYHKoZIzj0CAQYFK4EEAAEDLAAEAv4TwFN7vBGsqgfXk95ObV5clO7oAokHD7BdOP9YMh8ugAU21TjM2qPZ
私鑰： 
MDICAQAwEAYHKoZIzj0CAQYFK4EEAAEEGzAZAgEBBBTYJsR3BN7TFw7JHcAHFkwNmfil7w==
加密前: abc

解密後: abc

參考文檔3d

http://snowolf.iteye.com/blog/383412rest

http://baike.baidu.com/item/%E6%A4%AD%E5%9C%86%E5%8A%A0%E5%AF%86%E7%AE%97%E6%B3%95/10305582?sefr=cr