package com.at21.server.restful.security;
import java.security.Key;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
/**
* 字符串常用加密/解密工具类.
*
*RSA 参考 RSA
*/
public class Sec {
/**
* AES算法密钥生成器.
* @return 生成的密钥 它是一个32个字符的16进制字符串.
*/
public static String AESKey() {
try {
// Get the KeyGenerator
KeyGenerator keyGenerator = KeyGenerator.getInstance("AES");
keyGenerator.init(128); // 192 and 256 bits may not be available
// Generate the secret key specs.
SecretKey key = keyGenerator.generateKey();
byte[] raw = key.getEncoded();
return byteArr2HexStr(raw);
} catch (Exception e) {
return "";
}
}
/**
* 使用AES算法解密字符串.
* AES加密算法（美国国家标准局倡导的AES即将作为新标准取代DES）
* @param encrypted 要解密的字符串
* @param rawKey 密钥字符串, 要求为一个32位(或64位，或128位)的16进制数的字符串,否则会出错.
* 可以使用{@link #AESKey()}方法生成一个密钥,
* @return 解密之后的字符串
* @see #AESEncrypt(String, String)
*/
public static String AESDecrypt(String encrypted, String rawKey){
byte[] tmp = hexStr2ByteArr(encrypted);
byte[] key = hexStr2ByteArr(rawKey);
try {
SecretKeySpec sks = new SecretKeySpec(key, "AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.DECRYPT_MODE, sks);
byte[] decrypted = cipher.doFinal(tmp);
return new String(decrypted);
} catch (Exception e) {
return null;
}
}
/**
* 使用AES算法加密字符串.
* @param message 要加密的字符串.
* @param rawKey 密钥字符串, 要求为一个32位(或64位，或128位)的16进制数的字符串,否则会出错.
* 可以使用{@link #AESKey()}方法生成一个密钥,
* @return 加密之后的字符串
* @see #AESDecrypt(String, String)
*/
public static String AESEncrypt(String message, String rawKey){
byte[] key = hexStr2ByteArr(rawKey);
try {
SecretKeySpec sks = new SecretKeySpec(key, "AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, sks);
byte[] encrypted = cipher.doFinal(message.getBytes());
return byteArr2HexStr(encrypted);
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
/**
* 使用DES算法解密字符串.
* @param encrypted 要解密的字符串.
* @param rawKey 密钥字符串, 可以为任意字符, 但最长不得超过8个字符(如最超过，后面的字符会被丢弃).
* @return 解密之后的字符串.
* @see #DESEncrypt(String, String)
*/
public static String DESDecrypt(String encrypted, String rawKey){
//Security.addProvider(new com.sun.crypto.provider.SunJCE());
byte[] arrBTmp = rawKey.getBytes();
byte[] arrB = new byte[8]; // 创建一个空的8位字节数组（默认值为0）
for (int i = 0; i < arrBTmp.length && i < arrB.length; i++) // 将原始字节数组转换为8位
arrB[i] = arrBTmp[i];
try {
Key key = new SecretKeySpec(arrB, "DES");// 生成密钥
Cipher cipher = Cipher.getInstance("DES");
cipher.init(Cipher.DECRYPT_MODE, key);
return new String(cipher.doFinal(hexStr2ByteArr(encrypted)));
} catch (Exception e) {
return null;
}
}
/**
* 使用DES算法加密字符串.
* @param message 要加密的字符串.
* @param rawKey 密钥字符串, 可以为任意字符, 但最长不得超过8个字符(如最超过，后面的字符会被丢弃).
* @return 加密之后的字符串.
* @see #DESDecrypt(String, String)
*/
public static String DESEncrypt(String message, String rawKey) {
//报错了，用的时候再加入相关的jar包
//Security.addProvider(new com.sun.crypto.provider.SunJCE());
byte[] arrBTmp = rawKey.getBytes();
byte[] arrB = new byte[8]; // 创建一个空的8位字节数组（默认值为0）
for (int i = 0; i < arrBTmp.length && i < arrB.length; i++) // 将原始字节数组转换为8位
arrB[i] = arrBTmp[i];
try {
Key key = new SecretKeySpec(arrB, "DES");// 生成密钥
Cipher cipher = Cipher.getInstance("DES");
cipher.init(Cipher.ENCRYPT_MODE, key);
return byteArr2HexStr(cipher.doFinal(message.getBytes()));
} catch (Exception e) {
return null;
}
}
public static String md5(String message){
return MD5Encrypt( MD5Encrypt(message, 32), 32);
}
/**
* 使用MD5算法加密字符串.
* @param message 要加密的字符串.
* @param length 指定返回加密后字符串长度，其值必须是16或者32.
* @return 加密之后的字符串
*/
public static String MD5Encrypt(String message, int length){
try {
java.security.MessageDigest md = java.security.MessageDigest.getInstance("MD5");
md.update(message.getBytes());
byte b[] = md.digest();
int i;
StringBuilder buf = new StringBuilder("");
for (byte aB : b) {
i = aB;
if (i < 0) i += 256;
if (i < 16)
buf.append("0");
buf.append(Integer.toHexString(i));
}
String str32=buf.toString().toUpperCase();
if(length==32) return str32;
else if (length==16) return str32.substring(8,24);
else throw new Exception( "mod5 encrypt fail");
} catch (Exception e) {
return null;
}
}
/**
* Turns array of bytes into string
* @param buf Array of bytes to convert to hex string
* @return Generated hex string
*/
private static String byteArr2HexStr(byte[] buf) {
StringBuilder sb = new StringBuilder(buf.length * 2);
int i;
for (i = 0; i < buf.length; i++) {
if (((int) buf[i] & 0xff) < 0x10) sb.append("0");
sb.append(Long.toString((int) buf[i] & 0xff, 16));
}
return sb.toString();
}
/**
* 将表示16进制值的字符串转换为byte数组， 和public static String byteArr2HexStr(byte[] buf)互为可逆的转换过程
* @param src 需要转换的字符串
* @return 转换后的byte数组
*/
private static byte[] hexStr2ByteArr(String src) {
if (src.length() < 1) {
return null;
}
byte[] encrypted = new byte[src.length() / 2];
for (int i = 0; i < src.length() / 2; i++) {
int high = Integer.parseInt(src.substring(i * 2, i * 2 + 1), 16);
int low = Integer.parseInt(src.substring(i * 2 + 1, i * 2 + 2), 16);
encrypted[i] = (byte) (high * 16 + low);
}
return encrypted;
}
private Sec(){}
/**
* 由JS端base64加密算法加密的字符串解密
* @param input
* @return
*/
public static String decode64(String input) {
String keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
String extendEncryptKey = "1E65E6163E2D38BAD19299679F6387EC";
String output = "";
int chr1, chr2, chr3 = 0;
int enc1,enc2, enc3, enc4 = 0;
int i = 0;
if (input.length() % 4 != 0) {
return "";
}
do {
enc1 = keyStr.indexOf(input.charAt(i++));
enc2 = keyStr.indexOf(input.charAt(i++));
enc3 = keyStr.indexOf(input.charAt(i++));
enc4 = keyStr.indexOf(input.charAt(i++));
chr1 = (enc1 << 2) | (enc2 >> 4);
chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
chr3 = ((enc3 & 3) << 6) | enc4;
output = output + (char) chr1;
if (enc3 != 64) {
output += (char)(chr2);
}
if (enc4 != 64) {
output += (char)(chr3);
}
chr1 = chr2 = chr3 = 0;
enc1 = enc2 = enc3 = enc4 = 0;
} while (i < input.length());
output = output.substring(0, output.lastIndexOf(extendEncryptKey));
return output;
}
}