Android--DES加密解密
概念就不介绍了，自己百度，主要就是三步：创建Cipher对象，初始化Cipher，加密解密
调用DES加密算法包最精要的就是下面两句话：
Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, key, zeroIv);
CBC是工作模式，DES一共有电子密码本模式（ECB）、加密分组链接模式（CBC）、加密反馈模式（CFB）和输出反馈模式（OFB）四种模式，
PKCS5Padding是填充模式，还有其它的填充模式：
然后，cipher.init（)一共有三个参数：Cipher.ENCRYPT_MODE, key, zeroIv，zeroIv就是初始化向量，一个8为字符数组。
工作模式、填充模式、初始化向量这三种因素一个都不能少。否则，如果你不指定的话，那么就要程序就要调用默认实现。
DES加密类：
public class DES {
private static byte[] iv = {1,2,3,4,5,6,7,8};
public static String encryptDES(String encryptString, String encryptKey) throws Exception {
// IvParameterSpec zeroIv = new IvParameterSpec(new byte[8]);
IvParameterSpec zeroIv = new IvParameterSpec(iv);
SecretKeySpec key = new SecretKeySpec(encryptKey.getBytes(), "DES");
Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, key, zeroIv);
byte[] encryptedData = cipher.doFinal(encryptString.getBytes());
return Base64.encode(encryptedData);
}
public static String decryptDES(String decryptString, String decryptKey) throws Exception {
byte[] byteMi = new Base64().decode(decryptString);
IvParameterSpec zeroIv = new IvParameterSpec(iv);
// IvParameterSpec zeroIv = new IvParameterSpec(new byte[8]);
SecretKeySpec key = new SecretKeySpec(decryptKey.getBytes(), "DES");
Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
cipher.init(Cipher.DECRYPT_MODE, key, zeroIv);
byte decryptedData[] = cipher.doFinal(byteMi);
return new String(decryptedData);
}
}
BASE64工具类：
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
public class Base64 {
private static final char[] legalChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".toCharArray();
/**
* data[]进行编码
* @param data
* @return
*/
public static String encode(byte[] data) {
int start = 0;
int len = data.length;
StringBuffer buf = new StringBuffer(data.length * 3 / 2);
int end = len - 3;
int i = start;
int n = 0;
while (i <= end) {
int d = ((((int) data[i]) & 0x0ff) << 16)
| ((((int) data[i + 1]) & 0x0ff) << 8)
| (((int) data[i + 2]) & 0x0ff);
buf.append(legalChars[(d >> 18) & 63]);
buf.append(legalChars[(d >> 12) & 63]);
buf.append(legalChars[(d >> 6) & 63]);
buf.append(legalChars[d & 63]);
i += 3;
if (n++ >= 14) {
n = 0;
buf.append(" ");
}
}
if (i == start + len - 2) {
int d = ((((int) data[i]) & 0x0ff) << 16)
| ((((int) data[i + 1]) & 255) << 8);
buf.append(legalChars[(d >> 18) & 63]);
buf.append(legalChars[(d >> 12) & 63]);
buf.append(legalChars[(d >> 6) & 63]);
buf.append("=");
} else if (i == start + len - 1) {
int d = (((int) data[i]) & 0x0ff) << 16;
buf.append(legalChars[(d >> 18) & 63]);
buf.append(legalChars[(d >> 12) & 63]);
buf.append("==");
}
return buf.toString();
}
private static int decode(char c) {
if (c >= 'A' && c <= 'Z')
return ((int) c) - 65;
else if (c >= 'a' && c <= 'z')
return ((int) c) - 97 + 26;
else if (c >= '0' && c <= '9')
return ((int) c) - 48 + 26 + 26;
else
switch (c) {
case '+':
return 62;
case '/':
return 63;
case '=':
return 0;
default:
throw new RuntimeException("unexpected code: " + c);
}
}
/**
* Decodes the given Base64 encoded String to a new byte array. The byte
* array holding the decoded data is returned.
*/
public static byte[] decode(String s) {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
try {
decode(s, bos);
} catch (IOException e) {
throw new RuntimeException();
}
byte[] decodedBytes = bos.toByteArray();
try {
bos.close();
bos = null;
} catch (IOException ex) {
System.err.println("Error while decoding BASE64: " + ex.toString());
}
return decodedBytes;
}
private static void decode(String s, OutputStream os) throws IOException {
int i = 0;
int len = s.length();
while (true) {
while (i < len && s.charAt(i) <= ' ')
i++;
if (i == len)
break;
int tri = (decode(s.charAt(i)) << 18)
+ (decode(s.charAt(i + 1)) << 12)
+ (decode(s.charAt(i + 2)) << 6)
+ (decode(s.charAt(i + 3)));
os.write((tri >> 16) & 255);
if (s.charAt(i + 2) == '=')
break;
os.write((tri >> 8) & 255);
if (s.charAt(i + 3) == '=')
break;
os.write(tri & 255);
i += 4;
}
}
}
主函数：
public class main extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
String key = "12345678";
String text = "hello des";
try {
String result1 = DES.encryptDES(text,key);
String result2 = DES.decryptDES(result1, key);
Log.i("DES encode text is ", result1);
Log.i("DES encode text is ", result2);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
} import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
/**
* Created by Administrator on 2019/4/26
*
* desc: DES加密
*/
public class DES {
/**
* 生成秘钥
* @return
*/
public static String generateKey() {
KeyGenerator keyGen = null;
try {
keyGen = KeyGenerator.getInstance("DES"); // 秘钥生成器
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
keyGen.init(56); // 初始秘钥生成器
SecretKey secretKey = keyGen.generateKey(); // 生成秘钥
return Hex2Util.parseByte2HexStr(secretKey.getEncoded()); // 获取秘钥字节数组
}
/**
* DES加密
* @param content 字符串内容
* @param password 密钥
*/
public static String encrypt(String content, String password){
return des(content,password,Cipher.ENCRYPT_MODE);
}
/**
* DES解密
* @param content 字符串内容
* @param password 密钥
*/
public static String decrypt(String content, String password){
return des(content,password,Cipher.DECRYPT_MODE);
}
/**
* DES加密/解密公共方法
* @param content 字符串内容
* @param password 密钥
* @param type 加密：{@link Cipher#ENCRYPT_MODE}，解密：{@link Cipher#DECRYPT_MODE}
*/
private static String des(String content, String password, int type) {
try {
SecureRandom random = new SecureRandom();
DESKeySpec desKey = new DESKeySpec(password.getBytes());
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
Cipher cipher = Cipher.getInstance("DES");
cipher.init(type, keyFactory.generateSecret(desKey), random);
if (type == Cipher.ENCRYPT_MODE) {
byte[] byteContent = content.getBytes("utf-8");
return Hex2Util.parseByte2HexStr(cipher.doFinal(byteContent));
} else {
byte[] byteContent = Hex2Util.parseHexStr2Byte(content);
assert byteContent != null;
return new String(cipher.doFinal(byteContent));
}
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
}