package com.huawei.insa2.util;

import java.io.UnsupportedEncodingException;
import java.security.*;
import java.security.spec.InvalidKeySpecException;
import javax.crypto.*;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.DESedeKeySpec;

public class SecurityTools {

	public SecurityTools() {
	}

	public static String digest(String str) {
		try {
			MessageDigest md5 = MessageDigest.getInstance("SHA");
			md5.update(salt);
			String s = Base64.encode(md5.digest(str.getBytes()));
			return s;
		} catch (NoSuchAlgorithmException ex) {
			throw new UnsupportedOperationException(ex.toString());
		}
	}

	public static void md5(byte data[], int offset, int length, byte digest[],
			int dOffset) {
		try {
			MessageDigest md5 = MessageDigest.getInstance("MD5");
			md5.update(data, offset, length);
			md5.digest(digest, dOffset, 16);
		} catch (NoSuchAlgorithmException ex) {
			ex.printStackTrace();
		} catch (DigestException ex) {
			ex.printStackTrace();
		}
	}

	public static byte[] md5(byte data[], int offset, int length) {
		try {
			MessageDigest md5 = MessageDigest.getInstance("MD5");
			md5.update(data, offset, length);
			byte abyte0[] = md5.digest();
			return abyte0;
		} catch (NoSuchAlgorithmException ex) {
			ex.printStackTrace();
		}
		byte abyte1[] = null;
		return abyte1;
	}

	public static byte[] encrypt(byte key[], byte src[]) {
		try {
			byte abyte0[] = getCipher(key, 1).doFinal(src);
			return abyte0;
		} catch (BadPaddingException ex) {
			throw new UnsupportedOperationException(ex.toString());
		} catch (IllegalBlockSizeException ex) {
			throw new UnsupportedOperationException(ex.toString());
		}
	}

	public static String encrypt(String key, String src) {
		try {
			String s = Base64.encode(getCipher(key.getBytes("UTF8"), 1)
					.doFinal(src.getBytes("UTF8")));
			return s;
		} catch (UnsupportedEncodingException ex) {
			throw new UnsupportedOperationException(ex.toString());
		} catch (BadPaddingException ex) {
			throw new UnsupportedOperationException(ex.toString());
		} catch (IllegalBlockSizeException ex) {
			throw new UnsupportedOperationException(ex.toString());
		}
	}

	public static byte[] decrypt(byte key[], byte src[]) {
		try {
			byte abyte0[] = getCipher(key, 2).doFinal(src);
			return abyte0;
		} catch (IllegalBlockSizeException ex) {
			throw new UnsupportedOperationException(ex.toString());
		} catch (BadPaddingException ex) {
			throw new UnsupportedOperationException(ex.toString());
		}
	}

	public static String decrypt(String key, String src) {
		try {
			String s = new String(getCipher(key.getBytes("UTF8"), 2).doFinal(
					Base64.decode(src)), "UTF8");
			return s;
		} catch (UnsupportedEncodingException ex) {
			throw new UnsupportedOperationException(ex.toString());
		} catch (BadPaddingException ex) {
			throw new UnsupportedOperationException(ex.toString());
		} catch (IllegalBlockSizeException ex) {
			throw new UnsupportedOperationException(ex.toString());
		}
	}

	public static Cipher getCipher(byte key[], int mode) {
		try {
			if (key.length < 8) {
				byte oldkey[] = key;
				key = new byte[8];
				System.arraycopy(oldkey, 0, key, 0, oldkey.length);
			}
			SecretKeyFactory keyFactory;
			java.security.spec.KeySpec keySpec;
			Cipher c;
			if (key.length >= 24) {
				keyFactory = SecretKeyFactory.getInstance("DESede");
				keySpec = new DESedeKeySpec(key);
				c = Cipher.getInstance("DESede");
			} else {
				keyFactory = SecretKeyFactory.getInstance("DES");
				keySpec = new DESKeySpec(key);
				c = Cipher.getInstance("DES");
			}
			SecretKey k = keyFactory.generateSecret(keySpec);
			c.init(mode, k);
			Cipher cipher = c;
			return cipher;
		} catch (NoSuchAlgorithmException ex) {
			throw new UnsupportedOperationException(ex.toString());
		} catch (InvalidKeyException ex) {
			throw new UnsupportedOperationException(ex.toString());
		} catch (NoSuchPaddingException ex) {
			throw new UnsupportedOperationException(ex.toString());
		} catch (InvalidKeySpecException ex) {
			throw new UnsupportedOperationException(ex.toString());
		}
	}

	public static void main(String args[]) {
		Debug.dump(digest("hello world"));
		for (int i = 0; i < 1000; i++)
			decrypt("key", encrypt("key", "hello world"));

		Debug.dump(digest("hello world"));
	}

	private static final byte salt[] = "webplat".getBytes();

}