rsa-elgamal-dsa.rar_DSA算法_ELGAMAL_dsa_dsa签名算法_elgamal java

import java.security.AlgorithmParameterGenerator; import java.security.AlgorithmParameters; import java.security.Key; import java.security.KeyFactory; import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.PrivateKey; import java.security.PublicKey; import java.security.SecureRandom; import java.security.Security; import java.security.interfaces.RSAPrivateKey; import java.security.interfaces.RSAPublicKey; 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.interfaces.DHPrivateKey; import javax.crypto.interfaces.DHPublicKey; import javax.crypto.spec.DHParameterSpec; //import org.apache.commons.codec.binary.Base64; import org.bouncycastle.jce.provider.BouncyCastleProvider; /** * 非对称加密算法ElGamal算法组件 * 非对称算法一般是用来传送对称加密算法的密钥来使用的。相对于RSA算法，这个算法只支持私钥加密公钥解密 * @author kongqz * */ public class ElGamalCoder { //非对称密钥算法 public static final String KEY_ALGORITHM="ElGamal"; /** * 密钥长度，DH算法的默认密钥长度是1024 * 密钥长度必须是8的倍数，在160到16384位之间 * */ private static final int KEY_SIZE=256; //公钥 private static final String PUBLIC_KEY="ElGamalPublicKey"; //私钥 private static final String PRIVATE_KEY="ElGamalPrivateKey"; /** * 初始化密钥对 * @return Map 甲方密钥的Map * */ public static Map<String,Object> initKey() throws Exception{ //加入对BouncyCastle支持 Security.addProvider(new BouncyCastleProvider()); AlgorithmParameterGenerator apg=AlgorithmParameterGenerator.getInstance(KEY_ALGORITHM); //初始化参数生成器 apg.init(KEY_SIZE); //生成算法参数 AlgorithmParameters params=apg.generateParameters(); //构建参数材料 DHParameterSpec elParams=(DHParameterSpec)params.getParameterSpec(DHParameterSpec.class); //实例化密钥生成器 KeyPairGenerator kpg=KeyPairGenerator.getInstance(KEY_ALGORITHM) ; //初始化密钥对生成器 kpg.initialize(elParams,new SecureRandom()); KeyPair keyPair=kpg.generateKeyPair(); //甲方公钥 PublicKey publicKey= keyPair.getPublic(); //甲方私钥 PrivateKey privateKey= keyPair.getPrivate(); //将密钥存储在map中 Map<String,Object> keyMap=new HashMap<String,Object>(); keyMap.put(PUBLIC_KEY, publicKey); keyMap.put(PRIVATE_KEY, privateKey); return keyMap; } /** * 公钥加密 * @param data待加密数据 * @param key 密钥 * @return byte[] 加密数据 * */ public static byte[] encryptByPublicKey(byte[] data,byte[] key) throws Exception{ //实例化密钥工厂 KeyFactory keyFactory=KeyFactory.getInstance(KEY_ALGORITHM); //初始化公钥 //密钥材料转换 X509EncodedKeySpec x509KeySpec=new X509EncodedKeySpec(key); //产生公钥 PublicKey pubKey=keyFactory.generatePublic(x509KeySpec); //数据加密 Cipher cipher=Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.ENCRYPT_MODE, pubKey); return cipher.doFinal(data); } /** * 私钥解密 * @param data 待解密数据 * @param key 密钥 * @return byte[] 解密数据 * */ public static byte[] decryptByPrivateKey(byte[] data,byte[] key) throws Exception{ //取得私钥 PKCS8EncodedKeySpec pkcs8KeySpec=new PKCS8EncodedKeySpec(key); KeyFactory keyFactory=KeyFactory.getInstance(KEY_ALGORITHM); //生成私钥 PrivateKey privateKey=keyFactory.generatePrivate(pkcs8KeySpec); //数据解密 Cipher cipher=Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.DECRYPT_MODE, privateKey); return cipher.doFinal(data); } /** * 取得私钥 * @param keyMap 密钥map * @return byte[] 私钥 * */ public static byte[] getPrivateKey(Map<String,Object> keyMap){ Key key=(Key)keyMap.get(PRIVATE_KEY); return key.getEncoded(); } /** * 取得公钥 * @param keyMap 密钥map * @return byte[] 公钥 * */ public static byte[] getPublicKey(Map<String,Object> keyMap) throws Exception{ Key key=(Key) keyMap.get(PUBLIC_KEY); return key.getEncoded(); } /** * @param args * @throws Exception */ public static void main(String[] args) throws Exception { //初始化密钥 //生成密钥对 Map<String,Object> keyMap=ElGamalCoder.initKey(); //公钥 byte[] publicKey=ElGamalCoder.getPublicKey(keyMap); //私钥 byte[] privateKey=ElGamalCoder.getPrivateKey(keyMap); //System.out.println("公钥：/n"+Base64.encodeBase64String(publicKey)); //System.out.println("私钥：/n"+Base64.encodeBase64String(privateKey)); System.out.println("================密钥对构造完毕,甲方将公钥公布给乙方，开始进行加密数据的传输============="); String str="ElGamal密码交换算法"; System.out.println("/n===========甲方向乙方发送加密数据=============="); System.out.println("原文:"+str); //乙方使用公钥对数据进行加密 byte[] code2=ElGamalCoder.encryptByPublicKey(str.getBytes(), publicKey); //System.out.println("===========乙方使用公钥对数据进行加密=============="); //System.out.println("加密后的数据："+Base64.encodeBase64String(code2)); //甲方使用私钥对数据进行解密 byte[] decode2=ElGamalCoder.decryptByPrivateKey(code2, privateKey); System.out.println("甲方解密后的数据："+new String(decode2)); } }