package com.zzhua.rsa2; import org.apache.commons.codec.binary.Base64; import javax.crypto.Cipher; import java.security.*; import java.security.spec.PKCS8EncodedKeySpec; import java.security.spec.X509EncodedKeySpec; import java.util.HashMap;
import java.util.Map;
public class RSACoder {
public static final String KEY_ALGORITHM = "RSA";
public static final String SIGNATURE_ALGORITHM = "MD5withRSA";
private static final String PUBLIC_KEY = "RSAPublicKey";
private static final String PRIVATE_KEY = "RSAPrivateKey";
public static byte[] decryptBASE64(String key) {
return Base64.decodeBase64(key);
}
public static String encryptBASE64(byte[] bytes) {
return Base64.encodeBase64String(bytes);
}
/** * 用私钥对信息生成数字签名 * * @param data 加密数据 * @param privateKey 私钥 * @return * @throws Exception */
public static String sign(byte[] data, String privateKey) throws Exception {
// 解密由base64编码的私钥
byte[] keyBytes = decryptBASE64(privateKey);
// 构造PKCS8EncodedKeySpec对象
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
// KEY_ALGORITHM 指定的加密算法
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
// 取私钥匙对象
PrivateKey priKey = keyFactory.generatePrivate(pkcs8KeySpec);
// 用私钥对信息生成数字签名
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initSign(priKey);
signature.update(data);
return encryptBASE64(signature.sign());
}
/** * 校验数字签名 * * @param data 加密数据 * @param publicKey 公钥 * @param sign 数字签名 * @return 校验成功返回true 失败返回false * @throws Exception */
public static boolean verify(byte[] data, String publicKey, String sign)
throws Exception {
// 解密由base64编码的公钥
byte[] keyBytes = decryptBASE64(publicKey);
// 构造X509EncodedKeySpec对象
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
// KEY_ALGORITHM 指定的加密算法
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
// 取公钥匙对象
PublicKey pubKey = keyFactory.generatePublic(keySpec);
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initVerify(pubKey);
signature.update(data);
// 验证签名是否正常
return signature.verify(decryptBASE64(sign));
}
public static byte[] decryptByPrivateKey(byte[] data, String key) throws Exception{
// 对密钥解密
byte[] keyBytes = decryptBASE64(key);
// 取得私钥
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key 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);
}
/** * 解密<br> * 用私钥解密 * * @param data * @param key * @return * @throws Exception */
public static byte[] decryptByPrivateKey(String data, String key)
throws Exception {
return decryptByPrivateKey(decryptBASE64(data),key);
}
/** * 解密<br> * 用公钥解密 * * @param data * @param key * @return * @throws Exception */
public static byte[] decryptByPublicKey(byte[] data, String key)
throws Exception {
// 对密钥解密
byte[] keyBytes = decryptBASE64(key);
// 取得公钥
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key 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);
}
/** * 加密<br> * 用公钥加密 * * @param data * @param key * @return * @throws Exception */
public static byte[] encryptByPublicKey(String data, String key)
throws Exception {
// 对公钥解密
byte[] keyBytes = decryptBASE64(key);
// 取得公钥
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key 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.getBytes());
}
/** * 加密<br> * 用私钥加密 * * @param data * @param key * @return * @throws Exception */
public static byte[] encryptByPrivateKey(byte[] data, String key)
throws Exception {
// 对密钥解密
byte[] keyBytes = decryptBASE64(key);
// 取得私钥
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key 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 * @return * @throws Exception */
public static String getPrivateKey(Map<String, Key> keyMap)
throws Exception {
Key key = (Key) keyMap.get(PRIVATE_KEY);
return encryptBASE64(key.getEncoded());
}
/** * 取得公钥 * * @param keyMap * @return * @throws Exception */
public static String getPublicKey(Map<String, Key> keyMap)
throws Exception {
Key key = keyMap.get(PUBLIC_KEY);
return encryptBASE64(key.getEncoded());
}
/** * 初始化密钥 * * @return * @throws Exception */
public static Map<String, Key> initKey() throws Exception {
KeyPairGenerator keyPairGen = KeyPairGenerator
.getInstance(KEY_ALGORITHM);
keyPairGen.initialize(1024);
KeyPair keyPair = keyPairGen.generateKeyPair();
Map<String, Key> keyMap = new HashMap(2);
keyMap.put(PUBLIC_KEY, keyPair.getPublic());// 公钥
keyMap.put(PRIVATE_KEY, keyPair.getPrivate());// 私钥
return keyMap;
}
}
package com.zzhua.rsa2;
import org.junit.Before;
import org.junit.Test;
import java.security.Key;
import java.util.Map;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;
public class RSACoderTest {
private String publicKey;
private String privateKey;
@Before
public void setUp() throws Exception {
Map<String, Key> keyMap = RSACoder.initKey();
publicKey = RSACoder.getPublicKey(keyMap);
privateKey = RSACoder.getPrivateKey(keyMap);
System.err.println("公钥: \n\r" + publicKey);
System.err.println("私钥： \n\r" + privateKey);
}
@Test
public void test() throws Exception {
System.err.println("公钥加密——私钥解密");
String inputStr = "abc";
byte[] encodedData = RSACoder.encryptByPublicKey(inputStr, publicKey);
byte[] decodedData = RSACoder.decryptByPrivateKey(encodedData,privateKey);
String outputStr = new String(decodedData);
System.err.println("加密前: " + inputStr + "\n\r" + "解密后: " + outputStr);
assertEquals(inputStr, outputStr);
}
@Test
public void testSign() throws Exception {
System.err.println("私钥加密——公钥解密");
String inputStr = "sign";
byte[] data = inputStr.getBytes();
byte[] encodedData = RSACoder.encryptByPrivateKey(data, privateKey);
byte[] decodedData = RSACoder.decryptByPublicKey(encodedData, publicKey);
String outputStr = new String(decodedData);
System.err.println("加密前: " + inputStr + "\n\r" + "解密后: " + outputStr);
assertEquals(inputStr, outputStr);
System.err.println("私钥签名——公钥验证签名");
// 产生签名
String sign = RSACoder.sign(encodedData, privateKey);
System.err.println("签名:" + sign);
// 验证签名
boolean status = RSACoder.verify(encodedData, publicKey, sign);
System.err.println("状态:" + status);
assertTrue(status);
}
}