首先 有服务端生产一对公钥和私钥 我们在进行加密之前，先从服务器获取公钥，获取到公钥串之后，在对密码进行加密。

map.put("password", new String(Hex.encodeHex(RSAUtils.encryptByPublicKey(password,rsastr))));

此处，就是在登陆之前，对密码进行加密

password：登录密码 rsastr：从服务器获取的公钥串

Hex.encodeHex：对加密后的密码串进行编码，项目中需要集成相应的jar。

下面给出 RSAUtils的代码

import java.io.ByteArrayOutputStream;

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.Signature;

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公钥/私钥/签名工具包

*

*

* 罗纳德·李维斯特(Ron [R]ivest)、阿迪·萨莫尔(Adi [S]hamir)和伦纳德·阿德曼(Leonard [A]dleman)

*

*

* 字符串格式的密钥在未在特殊说明情况下都为BASE64编码格式

* 由于非对称加密速度极其缓慢，一般文件不使用它来加密而是使用对称加密，

* 非对称加密算法可以用来对对称加密的密钥加密，这样保证密钥的安全也就保证了数据的安全

*

*

* @author IceWee

* @version 1.0

* @date 2012-4-26

*/

public class RSAUtils {

/**

* 加密算法RSA

*/

public static final String KEY_ALGORITHM = "RSA";

/**

* 签名算法

*/

public static final String SIGNATURE_ALGORITHM = "MD5withRSA";

/**

* 获取公钥的key

*/

private static final String PUBLIC_KEY = "RSAPublicKey";

/**

* 获取私钥的key

*/

private static final String PRIVATE_KEY = "RSAPrivateKey";

/**

* RSA最大加密明文大小

*/

private static final int MAX_ENCRYPT_BLOCK = 117;

/**

* RSA最大解密密文大小

*/

private static final int MAX_DECRYPT_BLOCK = 128;

/**

*

* 生成密钥对(公钥和私钥)

*

*

* @return

* @throws Exception

*/

public static Map genKeyPair() throws Exception {

KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);

keyPairGen.initialize(1024);

KeyPair keyPair = keyPairGen.generateKeyPair();

RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();

RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();

Map keyMap = new HashMap(2);

keyMap.put(PUBLIC_KEY, publicKey);

keyMap.put(PRIVATE_KEY, privateKey);

return keyMap;

}

/**

*

* 用私钥对信息生成数字签名

*

*

* @param data 已加密数据

* @param privateKey 私钥(BASE64编码)

* @return

* @throws Exception

*/

public static String sign(byte[] data, String privateKey) throws Exception {

byte[] keyBytes = Base64Utils.decode(privateKey);

PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec);

Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);

signature.initSign(privateK);

signature.update(data);

return Base64Utils.encode(signature.sign());

}

/**

*

* 校验数字签名

*

*

*

* @param data 已加密数据

* @param publicKey 公钥(BASE64编码)

* @param sign 数字签名

* @return

* @throws Exception

*/

public static boolean verify(byte[] data, String publicKey, String sign)

throws Exception {

byte[] keyBytes = Base64Utils.decode(publicKey);

X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

PublicKey publicK = keyFactory.generatePublic(keySpec);

Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);

signature.initVerify(publicK);

signature.update(data);

return signature.verify(Base64Utils.decode(sign));

}

/**

*

* 私钥解密

*

*

* @param encryptedData 已加密数据

* @param privateKey 私钥(BASE64编码)

* @return

* @throws Exception

*/

public static byte[] decryptByPrivateKey(byte[] encryptedData, String privateKey)

throws Exception {

byte[] keyBytes = Base64Utils.decode(privateKey);

PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);

// Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());

Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");

cipher.init(Cipher.DECRYPT_MODE, privateK);

int inputLen = encryptedData.length;

ByteArrayOutputStream out = new ByteArrayOutputStream();

int offSet = 0;

byte[] cache;

int i = 0;

// 对数据分段解密

while (inputLen - offSet > 0) {

if (inputLen - offSet > MAX_DECRYPT_BLOCK) {

cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);

} else {

cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);

}

out.write(cache, 0, cache.length);

i++;

offSet = i * MAX_DECRYPT_BLOCK;

}

byte[] decryptedData = out.toByteArray();

out.close();

return decryptedData;

}

/**

*

* 公钥解密

*

*

* @param encryptedData 已加密数据

* @param publicKey 公钥(BASE64编码)

* @return

* @throws Exception

*/

public static byte[] decryptByPublicKey(byte[] encryptedData, String publicKey)

throws Exception {

byte[] keyBytes = Base64Utils.decode(publicKey);

X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

Key publicK = keyFactory.generatePublic(x509KeySpec);

// Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());

Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");

cipher.init(Cipher.DECRYPT_MODE, publicK);

int inputLen = encryptedData.length;

ByteArrayOutputStream out = new ByteArrayOutputStream();

int offSet = 0;

byte[] cache;

int i = 0;

// 对数据分段解密

while (inputLen - offSet > 0) {

if (inputLen - offSet > MAX_DECRYPT_BLOCK) {

cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);

} else {

cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);

}

out.write(cache, 0, cache.length);

i++;

offSet = i * MAX_DECRYPT_BLOCK;

}

byte[] decryptedData = out.toByteArray();

out.close();

return decryptedData;

}

/**

*

* 公钥加密

*

*

* @param sourcedata 源数据

* @param publicKey 公钥(BASE64编码)

* @return

* @throws Exception

*/

public static byte[] encryptByPublicKey(String sourcedata, String publicKey)

throws Exception {

byte[] data = sourcedata.getBytes();

byte[] keyBytes = Base64Utils.decode(publicKey);

X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

Key publicK = keyFactory.generatePublic(x509KeySpec);

// 对数据加密

// Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());

Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");

cipher.init(Cipher.ENCRYPT_MODE, publicK);

int inputLen = data.length;

ByteArrayOutputStream out = new ByteArrayOutputStream();

int offSet = 0;

byte[] cache;

int i = 0;

// 对数据分段加密

while (inputLen - offSet > 0) {

if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {

cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);

} else {

cache = cipher.doFinal(data, offSet, inputLen - offSet);

}

out.write(cache, 0, cache.length);

i++;

offSet = i * MAX_ENCRYPT_BLOCK;

}

byte[] encryptedData = out.toByteArray();

out.close();

return encryptedData;

}

/**

*

* 私钥加密

*

*

* @param data 源数据

* @param privateKey 私钥(BASE64编码)

* @return

* @throws Exception

*/

public static byte[] encryptByPrivateKey(byte[] data, String privateKey)

throws Exception {

byte[] keyBytes = Base64Utils.decode(privateKey);

PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);

// Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());

Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");

cipher.init(Cipher.ENCRYPT_MODE, privateK);

int inputLen = data.length;

ByteArrayOutputStream out = new ByteArrayOutputStream();

int offSet = 0;

byte[] cache;

int i = 0;

// 对数据分段加密

while (inputLen - offSet > 0) {

if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {

cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);

} else {

cache = cipher.doFinal(data, offSet, inputLen - offSet);

}

out.write(cache, 0, cache.length);

i++;

offSet = i * MAX_ENCRYPT_BLOCK;

}

byte[] encryptedData = out.toByteArray();

out.close();

return encryptedData;

}

/**

*

* 获取私钥

*

*

* @param keyMap 密钥对

* @return

* @throws Exception

*/

public static String getPrivateKey(Map keyMap)

throws Exception {

Key key = (Key) keyMap.get(PRIVATE_KEY);

return Base64Utils.encode(key.getEncoded());

}

/**

*

* 获取公钥

*

*

* @param keyMap 密钥对

* @return

* @throws Exception

*/

public static String getPublicKey(Map keyMap)

throws Exception {

Key key = (Key) keyMap.get(PUBLIC_KEY);

return Base64Utils.encode(key.getEncoded());

}

// 把byte[]元素之间添加空格，并转化成字符串返回，

public static String byteToString(byte[] resouce){

StringBuffer sb = new StringBuffer();

for (int i = 0; i < resouce.length; i++) {

if (i == resouce.length-1) {

sb.append(Byte.toString(resouce[i]));

}else{

sb.append(Byte.toString(resouce[i]));

sb.append(" ");

}

}

return sb.toString();

}

// 把字符串按照空格进行拆分成数组，然后转化成byte[],返回

public static byte[] stringToByte(String resouce){

String[] strArr = resouce.split(" ");

int len = strArr.length;

byte[] clone = new byte[len];

for (int i = 0; i < len; i++) {

clone[i] = Byte.parseByte(strArr[i]);

}

return clone;

}

}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。