RSA 实现
/*** 2008-6-11*/
package org.zlex.chapter08_2;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.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;/*** RSA安全编码组件* * @author 梁栋* @version 1.0*/
public abstract class RSACoder {/*** 非对称加密密钥算法*/public static final String KEY_ALGORITHM = "RSA";/*** 公钥*/private static final String PUBLIC_KEY = "RSAPublicKey";/*** 私钥*/private static final String PRIVATE_KEY = "RSAPrivateKey";/*** RSA密钥长度 * 默认1024位，* 密钥长度必须是64的倍数， * 范围在512至65536位之间。*/private static final int KEY_SIZE = 512;/*** 私钥解密* * @param data* 待解密数据* @param key* 私钥* @return byte[] 解密数据* @throws Exception*/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);// 对数据解密Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());cipher.init(Cipher.DECRYPT_MODE, privateKey);return cipher.doFinal(data);}/*** 公钥解密* * @param data* 待解密数据* @param key* 公钥* @return byte[] 解密数据* @throws Exception*/public static byte[] decryptByPublicKey(byte[] data, byte[] key)throws Exception {// 取得公钥X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(key);KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);// 生成公钥PublicKey publicKey = keyFactory.generatePublic(x509KeySpec);// 对数据解密Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());cipher.init(Cipher.DECRYPT_MODE, publicKey);return cipher.doFinal(data);}/*** 公钥加密* * @param data* 待加密数据* @param key* 公钥* @return byte[] 加密数据* @throws Exception*/public static byte[] encryptByPublicKey(byte[] data, byte[] key)throws Exception {// 取得公钥X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(key);KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);PublicKey publicKey = keyFactory.generatePublic(x509KeySpec);// 对数据加密Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());cipher.init(Cipher.ENCRYPT_MODE, publicKey);return cipher.doFinal(data);}/*** 私钥加密* * @param data* 待加密数据* @param key* 私钥* @return byte[] 加密数据* @throws Exception*/public static byte[] encryptByPrivateKey(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);// 对数据加密Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());cipher.init(Cipher.ENCRYPT_MODE, privateKey);return cipher.doFinal(data);}/*** 取得私钥* * @param keyMap* 密钥Map* @return byte[] 私钥* @throws Exception*/public static byte[] getPrivateKey(Map<String, Object> keyMap)throws Exception {Key key = (Key) keyMap.get(PRIVATE_KEY);return key.getEncoded();}/*** 取得公钥* * @param keyMap* 密钥Map* @return byte[] 公钥* @throws Exception*/public static byte[] getPublicKey(Map<String, Object> keyMap)throws Exception {Key key = (Key) keyMap.get(PUBLIC_KEY);return key.getEncoded();}/*** 初始化密钥* * @return Map 密钥Map* @throws Exception*/public static Map<String, Object> initKey() throws Exception {// 实例化密钥对生成器KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);// 初始化密钥对生成器keyPairGen.initialize(KEY_SIZE);// 生成密钥对KeyPair keyPair = keyPairGen.generateKeyPair();// 公钥RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();// 私钥RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();// 封装密钥Map<String, Object> keyMap = new HashMap<String, Object>(2);keyMap.put(PUBLIC_KEY, publicKey);keyMap.put(PRIVATE_KEY, privateKey);return keyMap;}
}
RSA 使用示例
/*** 2008-6-11*/
package org.zlex.chapter08_2;import static org.junit.Assert.*;import org.apache.commons.codec.binary.Base64;
import org.junit.Before;
import org.junit.Test;import java.util.Map;/*** RSA校验* * @author 梁栋* @version 1.0*/
public class RSACoderTest {/*** 公钥*/private byte[] publicKey;/*** 私钥*/private byte[] privateKey;/*** 初始化密钥* * @throws Exception*/@Beforepublic void initKey() throws Exception {// 初始化密钥Map<String, Object> keyMap = RSACoder.initKey();publicKey = RSACoder.getPublicKey(keyMap);privateKey = RSACoder.getPrivateKey(keyMap);System.err.println("公钥: \n" + Base64.encodeBase64String(publicKey));System.err.println("私钥： \n" + Base64.encodeBase64String(privateKey));}/*** 校验* * @throws Exception*/@Testpublic void test() throws Exception {System.err.println("\n---私钥加密——公钥解密---");String inputStr1 = "RSA加密算法";byte[] data1 = inputStr1.getBytes();System.err.println("原文:\n" + inputStr1);// 加密byte[] encodedData1 = RSACoder.encryptByPrivateKey(data1, privateKey);System.err.println("加密后:\n" + Base64.encodeBase64String(encodedData1));// 解密byte[] decodedData1 = RSACoder.decryptByPublicKey(encodedData1,publicKey);String outputStr1 = new String(decodedData1);System.err.println("解密后:\n" + outputStr1);// 校验assertEquals(inputStr1, outputStr1);System.err.println("\n---公钥加密——私钥解密---");String inputStr2 = "RSA Encypt Algorithm";byte[] data2 = inputStr2.getBytes();System.err.println("原文:\n" + inputStr2);// 加密byte[] encodedData2 = RSACoder.encryptByPublicKey(data2, publicKey);System.err.println("加密后:\n" + Base64.encodeBase64String(encodedData2));// 解密byte[] decodedData2 = RSACoder.decryptByPrivateKey(encodedData2,privateKey);String outputStr2 = new String(decodedData2);System.err.println("解密后: " + outputStr2);// 校验assertEquals(inputStr2, outputStr2);}}
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