java aes算法

package com.koolearn.etraining.util.aes;

import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.spec.AlgorithmParameterSpec;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;

public class AESEncrypter {
public static byte[] iv = new byte[] { 82, 22, 50, 44, -16, 124, -40, -114,
-87, -40, 37, 23, -56, 23, -33, 75 };

private static AESEncrypter aes = null;

public static byte[] key1 = new byte[] { -42, 35, 67, -86, 19, 29, -11, 84,
94, 111, 75, -104, 71, 46, 86, -21, -119, 110, -11, -32, -28, 91,
-33, -46, 99, 49, 2, 66, -101, -11, -8, 56 };

private AESEncrypter() {

}

public static synchronized AESEncrypter getInstance() {
if (aes == null) {
aes = new AESEncrypter();
}
return aes;
}

public String encrypt(String msg) {

String str = "";
try {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
kgen.init(128, new SecureRandom(key1));
AlgorithmParameterSpec paramSpec = new IvParameterSpec(iv);
SecretKey key = kgen.generateKey();
Cipher ecipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
ecipher.init(Cipher.ENCRYPT_MODE, key, paramSpec);
str = asHex(ecipher.doFinal(msg.getBytes()));
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (InvalidAlgorithmParameterException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
}
return str;
}

public String decrypt(String value) {
try {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
kgen.init(128, new SecureRandom(key1));
AlgorithmParameterSpec paramSpec = new IvParameterSpec(iv);
SecretKey key = kgen.generateKey();
Cipher dcipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
dcipher.init(Cipher.DECRYPT_MODE, key, paramSpec);
return new String(dcipher.doFinal(asBin(value)));
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (InvalidAlgorithmParameterException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
}
return "";
}

public static void main(String args[]) {
String str = AESEncrypter.getInstance().encrypt("lenovo_45666");
System.out.println(str);
System.out.println(AESEncrypter.getInstance().decrypt(str));
}

private String asHex(byte buf[]) {
StringBuffer strbuf = new StringBuffer(buf.length * 2);
int i;

for (i = 0; i < buf.length; i++) {
if (((int) buf[i] & 0xff) < 0x10)
strbuf.append("0");

strbuf.append(Long.toString((int) buf[i] & 0xff, 16));
}

return strbuf.toString();
}

private byte[] asBin(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;
}
}