AES加密:
<span style="font-size:18px;">package com.example.encrypdate.util;
import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
public class AES {
/**
* 加密
*
* @param content
* 需要加密的内容
* @param password
* 加密密码
* @return
*/
public static byte[] encrypt(String content, String password) {
try {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
kgen.init(128, new SecureRandom(password.getBytes()));
SecretKey secretKey = kgen.generateKey();
byte[] enCodeFormat = secretKey.getEncoded();
SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
Cipher cipher = Cipher.getInstance("AES");// 创建密码器
byte[] byteContent = content.getBytes("utf-8");
cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化
byte[] result = cipher.doFinal(byteContent);
return result; // 加密
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
}
return null;
}
/**
* 解密
*
* @param content
* 待解密内容
* @param password
* 解密密钥
* @return
*/
public static byte[] decrypt(byte[] content, String password) {
try {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
kgen.init(128, new SecureRandom(password.getBytes()));
SecretKey secretKey = kgen.generateKey();
byte[] enCodeFormat = secretKey.getEncoded();
SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
Cipher cipher = Cipher.getInstance("AES");// 创建密码器
cipher.init(Cipher.DECRYPT_MODE, key);// 初始化
byte[] result = cipher.doFinal(content);
return result; // 加密
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
}
return null;
}
/**
* 将十进制转换成16进制
*
* @param buf
* @return
*/
public static String parseByte2HexStr(byte buf[]) {
StringBuffer sb = new StringBuffer();
for (int i = 0; i < buf.length; i++) {
String hex = Integer.toHexString(buf[i] & 0xFF);
if (hex.length() == 1) {
hex = '0' + hex;
}
sb.append(hex.toUpperCase());
}
return sb.toString();
}
/**
* 将16进制转换为十进制
*
* @param hexStr
* @return
*/
public static byte[] parseHexStr2Byte(String hexStr) {
if (hexStr.length() < 1)
return null;
byte[] result = new byte[hexStr.length() / 2];
for (int i = 0; i < hexStr.length() / 2; i++) {
int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);
int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2),
16);
result[i] = (byte) (high * 16 + low);
}
return result;
}
}</span>
DES加密:
<span style="font-size:18px;">package com.example.encrypdate.util;
import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import android.util.Base64;
public class DES {
// 初始化向量,随机填充
private static byte[] iv = { 1, 2, 3, 4, 5, 6, 7, 8 };
/**
* @param encryptString
* 需要加密的明文
* @param encryptKey
* 秘钥
* @return 加密后的密文
* @throws Exception
*/
public static String encryptDES(String encryptString, String encryptKey)
throws Exception {
// 实例化IvParameterSpec对象,使用指定的初始化向量
IvParameterSpec zeroIv = new IvParameterSpec(iv);
// 实例化SecretKeySpec类,根据字节数组来构造SecretKey
SecretKeySpec key = new SecretKeySpec(encryptKey.getBytes(), "DES");
// 创建密码器
Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
// 用秘钥初始化Cipher对象
cipher.init(Cipher.ENCRYPT_MODE, key, zeroIv);
// 执行加密操作
byte[] encryptedData = cipher.doFinal(encryptString.getBytes());
return Base64.encodeToString(encryptedData, Base64.DEFAULT);
}
/****
*
* @param decrypString
* 密文
* @param decryptKey
* 解密密钥
* @return
* @throws Exception
*/
public static String decryptDES(String decrypString, String decryptKey)
throws Exception {
byte[] byteMi = Base64.decode(decrypString, Base64.DEFAULT);
// 实例化IvParameterSpec对象,使用指定的初始化向量
IvParameterSpec zeroIv = new IvParameterSpec(iv);
// 实例化SecretKeySpec类,根据字节数组来构造SecretKey
SecretKeySpec key = new SecretKeySpec(decryptKey.getBytes(), "DES");
// 创建密码器
Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
// 用秘钥初始化Cipher对象
cipher.init(Cipher.DECRYPT_MODE, key, zeroIv);
// 执行解密操作
byte[] decryptedData = cipher.doFinal(byteMi);
return new String(decryptedData);
}
}</span>
MD5加密:
<span style="font-size:18px;">package com.example.encrypdate.util;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
public class MD5 {
/***
* @param data
* @return
*/
public static String toMD5(String data) {
try {
// 实例化一个指定摘要算法为MD5的MessageDigest对象
MessageDigest algorithm = MessageDigest.getInstance("MD5");
// 重置摘要以供再次使用
algorithm.reset();
// 使用bytes更新摘要
algorithm.update(data.getBytes());
// 使用指定的byte数组对摘要进行最的更新,然后完成摘要计算
return toHexString(algorithm.digest(), "");
} catch (NoSuchAlgorithmException e) {
// TODO 自动生成的 catch 块
e.printStackTrace();
}
return "";
}
// 将字符串中的每个字符转换为十六进制
private static String toHexString(byte[] bytes, String separator) {
StringBuilder hexstring = new StringBuilder();
for (byte b : bytes) {
String hex = Integer.toHexString(0xFF & b);
if (hex.length() == 1) {
hexstring.append('0');
}
hexstring.append(hex);
}
return hexstring.toString();
}
}
</span>
测试文件:
<span style="font-size:18px;">package com.example.encrypdate;
import com.example.encrypdate.util.AES;
import com.example.encrypdate.util.DES;
import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.widget.TextView;
import com.example.encrypdate.util.MD5;
public class MainActivity extends Activity {
private TextView tv;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv = (TextView) this.findViewById(R.id.tv);
// DESTest();
// MD5Test();
AESTest();
}
public void DESTest() {
// 指定秘钥 只能是8位
String key = "12345678";
// 指定需要加密的明文
String text = "多少";
Log.i("DES", "DES加密明文:" + text + "\n加密秘钥:" + key);
// 调用DES加密
try {
String encryptResult = DES.encryptDES(text, key);
String decryptResult = DES.decryptDES(encryptResult, key);
tv.setText("加密结果:" + encryptResult + "\n解密结果:" + decryptResult);
Log.i("DES", "加密结果:" + encryptResult + "\n解密结果:" + decryptResult);
} catch (Exception e) {
// TODO 自动生成的 catch 块
e.printStackTrace();
}
}
private void AESTest() {
String content = "test3444";
String password = "11";
// 加密
byte[] encryptResult = AES.encrypt(content, password);
String encryptResultStr = AES.parseByte2HexStr(encryptResult);
// 解密
byte[] decryptFrom = AES.parseHexStr2Byte(encryptResultStr);
String decryptResult = new String(AES.decrypt(decryptFrom, password));
Log.i("AES", "密码:" + password + "\n加密前:" + content + "\n加密后:"
+ encryptResultStr + "\n解密后:" + decryptResult);
tv.setText("密码:" + password + "\n加密前:" + content + "\n加密后:"
+ encryptResultStr + "\n解密后:" + decryptResult);
}
private void MD5Test() {
String str = "1nakjnvjanbdvjk女嘉宾那覅v骄傲不能浪费的哪里方便v啊别v骄傲不能浪费的哪里方便v啊别v骄傲不能浪费的哪里方便v啊别浪费vu巴娄病v阿拉伯风v ";
String MD5Result = MD5.toMD5(str);
Log.i("MD5", str + " MD5加密结果:" + MD5Result);
tv.setText(str + " MD5加密结果:" + MD5Result);
}
}
</span>
完整工程地址:
http://download.youkuaiyun.com/detail/u014071669/7930951
另外,非对称加密RSA详解见:
http://blog.youkuaiyun.com/yongbingchao/article/details/39346099