package test.common; 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.spec.PKCS8EncodedKeySpec; import java.security.spec.X509EncodedKeySpec; import java.util.HashMap; import java.util.Map; import javax.crypto.Cipher; import javax.crypto.KeyAgreement; import javax.crypto.SecretKey; import javax.crypto.interfaces.DHPrivateKey; import javax.crypto.interfaces.DHPublicKey; import javax.crypto.spec.DHParameterSpec; import javax.crypto.spec.SecretKeySpec; import org.apache.commons.codec.binary.Base64; /** * 非对称加密算法DH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,所以这里我们用DH算法模拟密钥传送 * 原理:甲方生产随机公私钥,乙方用甲方的公钥生成乙方的公私钥对 * 甲方用甲方的私钥和乙方的公钥生成密钥,乙方用乙方的私钥和甲方的公钥生成密钥 * 甲乙双方在用密钥DES对称加密 * 对称加密DES算法继续做我们的数据加解密 * @author nicaisheng * */ public class DHCoderTest { //非对称密钥算法 public static final String KEY_ALGORITHM = "DH"; //本地密钥算法,即对称加密算法。可选des,aes,desede public static final String SECRET_ALGORITHM = "DES"; /** * 密钥长度,DH算法的默认密钥长度是1024 * 密钥长度必须是64的倍数,在512到1024位之间 * */ private static final int KEY_SIZE = 512; //公钥 private static final String PUBLIC_KEY="DHPublicKey"; //私钥 private static final String PRIVATE_KEY="DHPrivateKey"; /** * 初始化甲方密钥 * @return * @throws Exception */ public static Map<String,Object> initKey() throws Exception{ //实例化密钥生成器 KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(KEY_ALGORITHM); //初始化密钥生成器 keyPairGenerator.initialize(KEY_SIZE); //生成密钥对 KeyPair keyPair = keyPairGenerator.generateKeyPair(); //甲方公钥 DHPublicKey publicKey = (DHPublicKey) keyPair.getPublic(); //甲方私钥 DHPrivateKey privateKey = (DHPrivateKey) 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; } /** * 初始化乙方密钥 * @param key 甲方密钥(这个密钥是通过第三方途径传递的) * @return Map 乙方密钥的Map * */ public static Map<String,Object> initKey(byte[] key) throws Exception{ //解析甲方的公钥 //转换公钥的材料 X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(key); //实例化密钥工厂 KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); //产生公钥 PublicKey pubKey = keyFactory.generatePublic(x509KeySpec); //由甲方的公钥构造乙方密钥 DHParameterSpec dhParamSpec = ((DHPublicKey)pubKey).getParams(); //实例化密钥生成器 KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(keyFactory.getAlgorithm()); //初始化密钥生成器 keyPairGenerator.initialize(dhParamSpec); //产生密钥对 KeyPair keyPair = keyPairGenerator.generateKeyPair(); //乙方公钥 DHPublicKey publicKey=(DHPublicKey)keyPair.getPublic(); //乙方私钥 DHPrivateKey privateKey=(DHPrivateKey)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; } /** * 加密 * @param data待加密数据 * @param key 密钥 * @return byte[] 加密数据 * */ public static byte[] encrypt(byte[] data,byte[] key) throws Exception{ //生成本地密钥 SecretKey secretKey = new SecretKeySpec(key,SECRET_ALGORITHM); //数据加密 Cipher cipher = Cipher.getInstance(secretKey.getAlgorithm()); cipher.init(Cipher.ENCRYPT_MODE, secretKey); return cipher.doFinal(data); } /** * 解密 * @param data 待解密数据 * @param key 密钥 * @return byte[] 解密数据 * */ public static byte[] decrypt(byte[] data,byte[] key) throws Exception{ //生成本地密钥 SecretKey secretKey=new SecretKeySpec(key,SECRET_ALGORITHM); //数据解密 Cipher cipher=Cipher.getInstance(secretKey.getAlgorithm()); cipher.init(Cipher.DECRYPT_MODE, secretKey); return cipher.doFinal(data); } /** * 构建密钥 * @param publicKey 公钥 * @param privateKey 私钥 * @return byte[] 本地密钥 * */ public static byte[] getSecretKey(byte[] publicKey,byte[] privateKey) 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(publicKey); //产生公钥 PublicKey pubKey=keyFactory.generatePublic(x509KeySpec); //初始化私钥 //密钥材料转换 PKCS8EncodedKeySpec pkcs8KeySpec=new PKCS8EncodedKeySpec(privateKey); //产生私钥 PrivateKey priKey=keyFactory.generatePrivate(pkcs8KeySpec); //实例化 KeyAgreement keyAgree = KeyAgreement.getInstance(keyFactory.getAlgorithm()); //初始化 keyAgree.init(priKey); keyAgree.doPhase(pubKey, true); //生成本地密钥 SecretKey secretKey = keyAgree.generateSecret(SECRET_ALGORITHM); return secretKey.getEncoded(); } /** * 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(); } public static void main(String[] args) throws Exception { //生成甲方的密钥对 Map<String,Object> keyMap1 = DHCoderTest.initKey(); byte[] publicKey1 = DHCoderTest.getPublicKey(keyMap1); byte[] privateKey1 = DHCoderTest.getPrivateKey(keyMap1); System.out.println("甲方公钥:"+Base64.encodeBase64String(publicKey1)); System.out.println("甲方私钥:"+Base64.encodeBase64String(privateKey1)); //由甲方的公钥产生的密钥对 Map<String,Object> keyMap2 = DHCoderTest.initKey(publicKey1); byte[] publicKey2 = DHCoderTest.getPublicKey(keyMap2); byte[] privateKey2 = DHCoderTest.getPrivateKey(keyMap2); System.out.println("乙方公钥:"+Base64.encodeBase64String(publicKey2)); System.out.println("乙方私钥:"+Base64.encodeBase64String(privateKey2)); //组装甲方的本地加密密钥,由乙方的公钥和甲方的私钥组合而成 byte[] key1=DHCoderTest.getSecretKey(publicKey2, privateKey1); System.out.println("甲方的本地密钥:"+Base64.encodeBase64String(key1)); //组装乙方的本地加密密钥,由甲方的公钥和乙方的私钥组合而成 byte[] key2=DHCoderTest.getSecretKey(publicKey1, privateKey2); System.out.println("乙方的本地密钥:"+Base64.encodeBase64String(key2)); System.out.println("甲方的本地密钥==乙方的本地密钥:"+Base64.encodeBase64String(key1).equals(Base64.encodeBase64String(key2))); System.out.println("================密钥对构造完毕,开始进行加密数据的传输============="); String str = "密码交换算法"; System.out.println("原文:"+str); System.out.println("===========使用甲方本地密钥对进行数据加密=============="); byte[] code1 = DHCoderTest.encrypt(str.getBytes(), key1); System.out.println("加密后的数据:"+Base64.encodeBase64String(code1)); System.out.println("===========使用乙方本地密钥对数据进行解密=============="); byte[] decode1 = DHCoderTest.decrypt(code1, key2); System.out.println("乙方解密后的数据:"+new String(decode1)); } }
DH加密算法
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转载自ncs123.iteye.com/blog/2268269
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