学步园

import java.io.ByteArrayOutputStream;
import java.security.Key;
import java.security.MessageDigest;

import javax.crypto.Cipher;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

/**
* Security 提供了一个安全算法类,其中包括对称密码算法和散列算法
*/
public final class EbotongSecurity {
// The length of Encryptionstring should be 8 bytes and not be
// a weak key
private final static BASE64Encoder base64encoder = new BASE64Encoder();
private final static BASE64Decoder base64decoder = new BASE64Decoder();
private final static String encoding = "gbk";
private final static String sKey = "AD67EA2F3BE6E5ADD368DFE03120B5DF92A8FD8FEC2F0746";

/**
* 加密字符串
*/
public static String ebotongEncrypto(String str) {
   String result = str;
   if (str != null && str.length() > 0) {
    try {
     byte[] encodeByte = symmetricEncrypto(str.getBytes(encoding));
     result = base64encoder.encode(encodeByte);
    } catch (Exception e) {
     e.printStackTrace();
    }
   }
   return result;
}

/**
* 解密字符串
*/
public static String ebotongDecrypto(String str) {
   String result = str;
   if (str != null && str.length() > 0) {
    try {
     byte[] encodeByte = base64decoder.decodeBuffer(str);
     byte[] decoder = EbotongSecurity.symmetricDecrypto(encodeByte);
     result = new String(decoder, encoding);
    } catch (Exception e) {
     e.printStackTrace();
    }
   }
   return result;
}

/**
* 对称加密方法
*
* @param byteSource
*            需要加密的数据
* @return 经过加密的数据
* @throws Exception
*/
public static byte[] symmetricEncrypto(byte[] byteSource) throws Exception {
   ByteArrayOutputStream baos = new ByteArrayOutputStream();
   try {
    int mode = Cipher.ENCRYPT_MODE;
    SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
    byte[] keyData = sKey.getBytes();
    DESKeySpec keySpec = new DESKeySpec(keyData);
    Key key = keyFactory.generateSecret(keySpec);
    Cipher cipher = Cipher.getInstance("DES");
    cipher.init(mode, key);
    byte[] result = cipher.doFinal(byteSource);
    // int blockSize = cipher.getBlockSize();
    // int position = 0;
    // int length = byteSource.length;
    // boolean more = true;
    // while (more) {
    // if (position + blockSize <= length) {
    // baos.write(cipher.update(byteSource, position, blockSize));
    // position += blockSize;
    // } else {
    // more = false;
    // }
    // }
    // if (position < length) {
    // baos.write(cipher.doFinal(byteSource, position, length
    // - position));
    // } else {
    // baos.write(cipher.doFinal());
    // }
    // return baos.toByteArray();
    return result;
   } catch (Exception e) {
    throw e;
   } finally {
    baos.close();
   }
}

/**
* 对称解密方法
*
* @param byteSource
*            需要解密的数据
* @return 经过解密的数据
* @throws Exception
*/
public static byte[] symmetricDecrypto(byte[] byteSource) throws Exception {
   ByteArrayOutputStream baos = new ByteArrayOutputStream();
   try {
    int mode = Cipher.DECRYPT_MODE;
    SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
    byte[] keyData = sKey.getBytes();
    DESKeySpec keySpec = new DESKeySpec(keyData);
    Key key = keyFactory.generateSecret(keySpec);
    Cipher cipher = Cipher.getInstance("DES");
    cipher.init(mode, key);
    byte[] result = cipher.doFinal(byteSource);
    // int blockSize = cipher.getBlockSize();
    // int position = 0;
    // int length = byteSource.length;
    // boolean more = true;
    // while (more) {
    // if (position + blockSize <= length) {
    // baos.write(cipher.update(byteSource, position, blockSize));
    // position += blockSize;
    // } else {
    // more = false;
    // }
    // }
    // if (position < length) {
    // baos.write(cipher.doFinal(byteSource, position, length
    // - position));
    // } else {
    // baos.write(cipher.doFinal());
    // }
    // return baos.toByteArray();
    return result;
   } catch (Exception e) {
    throw e;
   } finally {
    baos.close();
   }
}

/**
* 散列算法
*
* @param byteSource
*            需要散列计算的数据
* @return 经过散列计算的数据
* @throws Exception
*/
public static byte[] hashMethod(byte[] byteSource) throws Exception {
   try {
    MessageDigest currentAlgorithm = MessageDigest.getInstance("SHA-1");
    currentAlgorithm.reset();
    currentAlgorithm.update(byteSource);
    return currentAlgorithm.digest();
   } catch (Exception e) {
    throw e;
   }
}

}