很多东西其实代码中提现的更加淋漓尽致
package com.lpf.encryptways;
import javax.crypto.Cipher;
import com.lpf.util.Base64Util;
import java.security.*;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
public class RSA {
//非对称密钥算法
private static final String KEY_ALGORITHM = "RSA";
//密钥长度，在512到65536位之间，建议不要太长，否则速度很慢，生成的加密数据很长
private static final int KEY_SIZE = 512;
//字符编码
private static final String CHARSET = "UTF-8";
/**
* 生成密钥对
*
* @return KeyPair 密钥对
*/
public static KeyPair getKeyPair() throws Exception {
return getKeyPair(null);
}
/**
* 生成密钥对
* @param password 生成密钥对的密码
* @return
* @throws Exception
*/
public static KeyPair getKeyPair(String password) throws Exception {
//实例化密钥生成器
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(KEY_ALGORITHM);
//初始化密钥生成器
if(password == null){
keyPairGenerator.initialize(KEY_SIZE);
}else {
SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
secureRandom.setSeed(password.getBytes(CHARSET));
keyPairGenerator.initialize(KEY_SIZE, secureRandom);
}
//生成密钥对
return keyPairGenerator.generateKeyPair();
}
/**
* 取得私钥
*
* @param keyPair 密钥对
* @return byte[] 私钥
*/
public static byte[] getPrivateKeyBytes(KeyPair keyPair) {
return keyPair.getPrivate().getEncoded();
}
/**
* 取得Base64编码的私钥
*
* @param keyPair 密钥对
* @return String Base64编码的私钥
*/
public static String getPrivateKey(KeyPair keyPair) {
return Base64Util.encode(getPrivateKeyBytes(keyPair));
}
/**
* 取得公钥
*
* @param keyPair 密钥对
* @return byte[] 公钥
*/
public static byte[] getPublicKeyBytes(KeyPair keyPair) {
return keyPair.getPublic().getEncoded();
}
/**
* 取得Base64编码的公钥
*
* @param keyPair 密钥对
* @return String Base64编码的公钥
*/
public static String getPublicKey(KeyPair keyPair) {
return Base64Util.encode(getPublicKeyBytes(keyPair));
}
/**
* 私钥加密
*
* @param data 待加密数据
* @param privateKey 私钥字节数组
* @return byte[] 加密数据
*/
public static byte[] encryptByPrivateKey(byte[] data, byte[] privateKey) throws Exception {
//实例化密钥工厂
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
//生成私钥
PrivateKey key = keyFactory.generatePrivate(new PKCS8EncodedKeySpec(privateKey));
//数据加密
Cipher cipher = Cipher.getInstance(KEY_ALGORITHM);
cipher.init(Cipher.ENCRYPT_MODE, key);
return cipher.doFinal(data);
}
/**
* 私钥加密
*
* @param data 待加密数据
* @param privateKey Base64编码的私钥
* @return String Base64编码的加密数据
*/
public static String encryptByPrivateKey(String data, String privateKey) throws Exception {
byte[] key = Base64Util.decode(privateKey);
return Base64Util.encode(encryptByPrivateKey(data.getBytes(CHARSET), key));
}
/**
* 公钥加密
*
* @param data 待加密数据
* @param publicKey 公钥字节数组
* @return byte[] 加密数据
*/
public static byte[] encryptByPublicKey(byte[] data, byte[] publicKey) throws Exception {
//实例化密钥工厂
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
//生成公钥
PublicKey key = keyFactory.generatePublic(new X509EncodedKeySpec(publicKey));
//数据加密
Cipher cipher = Cipher.getInstance(KEY_ALGORITHM);
cipher.init(Cipher.ENCRYPT_MODE, key);
return cipher.doFinal(data);
}
/**
* 公钥加密
*
* @param data 待加密数据
* @param publicKey Base64编码的公钥
* @return String Base64编码的加密数据
*/
public static String encryptByPublicKey(String data, String publicKey) throws Exception {
byte[] key = Base64Util.decode(publicKey);
return Base64Util.encode(encryptByPublicKey(data.getBytes(CHARSET), key));
}
/**
* 私钥解密
*
* @param data 待解密数据
* @param privateKey 私钥字节数组
* @return byte[] 解密数据
*/
public static byte[] decryptByPrivateKey(byte[] data, byte[] privateKey) throws Exception {
//实例化密钥工厂
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
//生成私钥
PrivateKey key = keyFactory.generatePrivate(new PKCS8EncodedKeySpec(privateKey));
//数据解密
Cipher cipher = Cipher.getInstance(KEY_ALGORITHM);
cipher.init(Cipher.DECRYPT_MODE, key);
return cipher.doFinal(data);
}
/**
* 私钥解密
*
* @param data Base64编码的待解密数据
* @param privateKey Base64编码的私钥
* @return String 解密数据
*/
public static String decryptByPrivateKey(String data, String privateKey) throws Exception {
byte[] key =Base64Util.decode(privateKey);
return new String(decryptByPrivateKey(Base64Util.decode(data), key), CHARSET);
}
/**
* 公钥解密
*
* @param data 待解密数据
* @param publicKey 公钥字节数组
* @return byte[] 解密数据
*/
public static byte[] decryptByPublicKey(byte[] data, byte[] publicKey) throws Exception {
//实例化密钥工厂
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
//产生公钥
PublicKey key = keyFactory.generatePublic(new X509EncodedKeySpec(publicKey));
//数据解密
Cipher cipher = Cipher.getInstance(KEY_ALGORITHM);
cipher.init(Cipher.DECRYPT_MODE, key);
return cipher.doFinal(data);
}
/**
* 公钥解密
*
* @param data Base64编码的待解密数据
* @param publicKey Base64编码的公钥
* @return String 解密数据
*/
public static String decryptByPublicKey(String data, String publicKey) throws Exception {
byte[] key = Base64Util.decode(publicKey);
return new String(decryptByPublicKey(Base64Util.decode(data), key), CHARSET);
}
/**
* 测试加解密方法
*
* @param args
* @throws Exception
*/
public static void main(String[] args) throws Exception {
//生成密钥对，一般生成之后可以放到配置文件中
KeyPair keyPair = RSA.getKeyPair();
//公钥
String publicKey = RSA.getPublicKey(keyPair);
//私钥
String privateKey = RSA.getPrivateKey(keyPair);
System.out.println("\n===========生成私钥，公钥==============");
System.out.println("公钥：\n" + publicKey);
System.out.println("私钥：\n" + privateKey);
String data = "非对称加密——RSA加解密测试XXXXXX";//若太长则分段加密
{
System.out.println("\n===========私钥加密，公钥解密==============");
String s1 = RSA.encryptByPrivateKey(data, privateKey);
System.out.println("加密后的数据:" + s1);
String s2 = RSA.decryptByPublicKey(s1, publicKey);
System.out.println("解密后的数据:" + s2 + "\n\n");
}
{
System.out.println("\n===========公钥加密，私钥解密==============");
String s1 = RSA.encryptByPublicKey(data, publicKey);
System.out.println("加密后的数据:" + s1);
String s2 = RSA.decryptByPrivateKey(s1, privateKey);
System.out.println("解密后的数据:" + s2 + "\n\n");
}
}
}
Base64Utils
package com.lpf.util;
import java.io.ByteArrayOutputStream;
public class Base64Util {
private static final char[] base64EncodeChars = new char[] { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q',
'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r',
's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/' };
private static byte[] base64DecodeChars = new byte[] { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60,
61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1,
-1, -1, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1 };
private Base64Util() {
}
/**
* 将字节数组编码为字符串
*
* @param data
*/
public static String encode(byte[] data) {
StringBuffer sb = new StringBuffer();
int len = data.length;
int i = 0;
int b1, b2, b3;
while (i < len) {
b1 = data[i++] & 0xff;
if (i == len) {
sb.append(base64EncodeChars[b1 >>> 2]);
sb.append(base64EncodeChars[(b1 & 0x3) << 4]);
sb.append("==");
break;
}
b2 = data[i++] & 0xff;
if (i == len) {
sb.append(base64EncodeChars[b1 >>> 2]);
sb.append(base64EncodeChars[((b1 & 0x03) << 4) | ((b2 & 0xf0) >>> 4)]);
sb.append(base64EncodeChars[(b2 & 0x0f) << 2]);
sb.append("=");
break;
}
b3 = data[i++] & 0xff;
sb.append(base64EncodeChars[b1 >>> 2]);
sb.append(base64EncodeChars[((b1 & 0x03) << 4) | ((b2 & 0xf0) >>> 4)]);
sb.append(base64EncodeChars[((b2 & 0x0f) << 2) | ((b3 & 0xc0) >>> 6)]);
sb.append(base64EncodeChars[b3 & 0x3f]);
}
return sb.toString();
}
/**
* 灏哹ase64瀛楃涓茶В鐮佷负瀛楄妭鏁扮粍
*
* @param str
*/
public static byte[] decode(String str) throws Exception {
byte[] data = str.getBytes("GBK");
int len = data.length;
ByteArrayOutputStream buf = new ByteArrayOutputStream(len);
int i = 0;
int b1, b2, b3, b4;
while (i < len) {
/* b1 */
do {
b1 = base64DecodeChars[data[i++]];
} while (i < len && b1 == -1);
if (b1 == -1) {
break;
}
/* b2 */
do {
b2 = base64DecodeChars[data[i++]];
} while (i < len && b2 == -1);
if (b2 == -1) {
break;
}
buf.write((b1 << 2) | ((b2 & 0x30) >>> 4));
/* b3 */
do {
b3 = data[i++];
if (b3 == 61) {
return buf.toByteArray();
}
b3 = base64DecodeChars[b3];
} while (i < len && b3 == -1);
if (b3 == -1) {
break;
}
buf.write(((b2 & 0x0f) << 4) | ((b3 & 0x3c) >>> 2));
/* b4 */
do {
b4 = data[i++];
if (b4 == 61) {
return buf.toByteArray();
}
b4 = base64DecodeChars[b4];
} while (i < len && b4 == -1);
if (b4 == -1) {
break;
}
buf.write(((b3 & 0x03) << 6) | b4);
}
return buf.toByteArray();
}
}