RSA加密工具类（待更新）

package com.bjsasc.szcloud.util;

import static org.junit.Assert.assertEquals;

import java.security.Key;
import java.security.KeyFactory;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

import javax.crypto.Cipher;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

public class Encode {
public static final String KEY_ALGORITHM = "RSA";

/**
* 加密<br>
* 用公钥加密
*
* @param data
* @param key
* @return
* @throws Exception
*/
public static byte[] encryptByPublicKey(byte[] 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);
}

/**
* 解密<br>
* 用私钥解密
*
* @param data
* @param key
* @return
* @throws Exception
*/
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);
}

/**
* BASE64解密
*
* @param key
* @return
* @throws Exception
*/
public static byte[] decryptBASE64(String key) throws Exception {
return (new BASE64Decoder()).decodeBuffer(key);
}

/**
* BASE64加密
*
* @param key
* @return
* @throws Exception
*/
public static String encryptBASE64(byte[] key) throws Exception {
return (new BASE64Encoder()).encodeBuffer(key);
}

public static String toUTFString(byte[] str) throws Exception {
return new String(str,"UTF-8");
}

public static void main(String[] args) throws Exception{
System.err.println("公钥加密——私钥解密");
String inputStr = "abfdsfdsfdsfdsc";
String publicKey= "MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBAJpUSS4d0vMBfDCIFg2kQOycrn1v6NNDNmzOIv3NyVe6"
+"8gRwE74pKk7mQ8hPpreAkx14bOoL/R1l5pDd8sT7PCsCAwEAAQ==";
String privateKey = "MIIBVQIBADANBgkqhkiG9w0BAQEFAASCAT8wggE7AgEAAkEAmlRJLh3S8wF8MIgWDaRA7JyufW/o"
+"00M2bM4i/c3JV7ryBHATvikqTuZDyE+mt4CTHXhs6gv9HWXmkN3yxPs8KwIDAQABAkEAlV/paQqS"
+"6IRSeQLvHYsTEDHjLiRIXVtb7VpkQfaR4CffEuzEk2IBsIv+Pk6G+ZwfbBohmz+F1T1giWEv4EPM"
+"8QIhANetV+ojkIUxbP/62B1j0WUPt/yRJkaMdrkSj1eunCADAiEAty67wwv0R9B3/5v4JpdzyRtC"
+"3Q6M1VoSRw6M0ODNXrkCIHE/R+ZdfkkxxrYylL/55b1XH5iy7pIkt0I+iJ3VxYzZAiEAsDhO/HXV"
+"i/hqWAVtFYMBKegFzK6goOZDSwQeRxrbtlECIGUKy3KOs8XOS/5jL/2mKvzIQFQSGPnhyQibsMY0"
+"MHUH";

byte[] data = inputStr.getBytes();

byte[] encodedData = encryptByPublicKey(data, publicKey);

String code64 = null;
try {
code64 = encryptBASE64(encodedData);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

System.out.println("code64 = "+code64);

byte[] decode64 = null;
try {
decode64 = decryptBASE64(code64);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

byte[] decodedData = decryptByPrivateKey(decode64,
privateKey);
String outputStr = toUTFString(decodedData);
System.err.println("加密前: " + inputStr + "\n\r" + "解密后: " + toUTFString(decodedData));
assertEquals(inputStr, outputStr);
}
}