java的常用 MD5 DES加密代码【转】
import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
/**
* 一般加密解密工具<br>
* DESede/DES/BlowFish<br>
* DES的密钥(key)长度是为8个字节,加密解密的速度是最快的<br>
* DESede的密钥(key)长度是24个字节<br>
* BlowFish的密钥(key)是可变的 加密最快，强度最高,密钥长度范围(1<=key<=16)<br>
*
* @author songdawei
* @version 1.0
* @date 2008-10-20
*/
public class SecretCodeUtil {
public final static String DES = "DES";
public final static String DESEDE = "DESede";
public final static String BLOWFISH = "BlowFish";
public final static String MD5 = "MD5";
/**
* md5加密
*
* @param plainText
* @return
*/
public static String getMD5ofStr(String plainText) {
try {
return getMD5ofStr(string2Bytes(plainText));
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
public static String getMD5ofStr(byte str[]) {
try {
MessageDigest md = MessageDigest.getInstance(MD5);
md.update(str);
byte b[] = md.digest();
return bytes2HexString(b);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 对数据源进行加密
*
* @param src
* 数据源
* @param key
* 密钥
* @param name
* 算法的名称
* @return 返回加密后的数据
* @throws Exception
*/
public static byte[] encrypt(byte[] src, byte[] key, String name)
throws Exception {
SecretKeySpec securekey = new SecretKeySpec(key, name);
// Cipher对象实际完成加密操作
Cipher cipher = Cipher.getInstance(name);
// 用密匙初始化Cipher对象
cipher.init(Cipher.ENCRYPT_MODE, securekey);
// 现在，获取数据并加密
// 正式执行加密操作
return cipher.doFinal(src);
}
/**
* 对加密的数据源进行解密
*
* @param src
* 数据源
* @param key
* 密钥
* @param name
* 算法的名称
* @return 返回解密后的原始数据
* @throws Exception
*/
public static byte[] decrypt(byte[] src, byte[] key, String name)
throws Exception {
SecretKeySpec securekey = new SecretKeySpec(key, name);
// Cipher对象实际完成解密操作
Cipher cipher = Cipher.getInstance(name);
// 用密匙初始化Cipher对象
cipher.init(Cipher.DECRYPT_MODE, securekey);
// 现在，获取数据并解密
// 正式执行解密操作
return cipher.doFinal(src);
}
/**
* 二行制转字符串
*
* @param b
* @return
*/
public static String bytes2HexString(byte[] bytes) {
String hs = null;
if (bytes != null) {
final int size = bytes.length;
if (size > 0) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < size; i++) {
String tmp = (java.lang.Integer.toHexString(bytes[i] & 0XFF));
if (tmp.length() == 1) {
sb.append("0" + tmp);
} else {
sb.append(tmp);
}
}
hs = sb.toString().toUpperCase();
}
}
return hs;
}
public static byte[] hex2byte(byte[] b) {
if ((b.length % 2) != 0) {
return null;
}
byte[] b2 = new byte[b.length / 2];
for (int n = 0; n < b.length; n += 2) {
String item = new String(b, n, 2);
b2[n / 2] = (byte) Integer.parseInt(item, 16);
}
return b2;
}
/**
* 十六进位格式字符串转二进制流。
*
* @param hs String
* @return byte[]
*/
public static byte[] hexString2Bytes (String hs) {
byte[] bytes = null;
if (hs != null) {
final int size = (hs.length()) / 2;
if (size > 0) {
bytes = new byte[size];
for (int i = 0; i < size; i++) {
String hsByte = hs.substring(i * 2, i * 2 + 2);
byte b = 0;
try {
b = (byte) (Integer.parseInt(hsByte, 16));
} catch (java.lang.NumberFormatException e) {
b = 0;
}
bytes[i] = b;
}
}
}
return bytes;
}
/**
* 字符串解密
*
* @param data
* 字符串加密数据
* @param key
* 密钥
* @param name
* 算法名称
* @return
* @throws Exception
*/
public static String decrypt(String data, String key, String name) {
try {
return new String(decrypt(hex2byte(data.getBytes()),
string2Bytes(key), name));
} catch (Exception e) {
}
return null;
}
/**
* 字符串解密
*
* @param data
* 字符串加密数据
* @param key
* 密钥
* @param name
* 算法名称
* @return
* @throws Exception
*/
public static String decrypt(String data, byte[] key, String name) {
try {
return new String(decrypt(hex2byte(data.getBytes()),key, name));
} catch (Exception e) {
}
return null;
}
/**
* 把字符串转化成 Unicode Bytes.
*
* @param s String
* @return byte[]
*/
public static byte [] string2Bytes(String s) {
byte[] bytes = null;
if (s != null) {
try {
bytes = s.getBytes("utf-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
}
return bytes;
}
/**
* 根据 Unicode Bytes 构造字符串.
*
* @param bytes byte[]
* @return String
*/
public static String bytes2String (byte[] bytes) {
String s = null;
if (bytes != null) {
try {
s = new String(bytes, "utf-8");
} catch (Exception e) {
e.printStackTrace();
}
}
return s;
}
/**
* 字符串加密
*
* @param data
* 字符串数据
* @param key
* 密钥
* @param name
* 算法名称
* @throws Exception
*/
public static String encrypt(String data, byte[] key, String name) {
try {
return bytes2HexString(encrypt(data.getBytes(), key, name));
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 字符串加密
*
* @param data
* 字符串数据
* @param key
* 密钥
* @param name
* 算法名称
* @throws Exception
*/
public static String encrypt(String data, String key, String name) {
try {
return bytes2HexString(encrypt(data.getBytes(), string2Bytes(key), name));
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
}