Android编程加密算法小结(AES、Base64、RAS加密算法)

import javax.crypto.Cipher; import javax.crypto.KeyGenerator;

import javax.crypto.SecretKey; import javax.crypto.spec.SecretKeySpec;

/** * AES加密解密算法

* * @author long

* */

public class Encryption { private final static String HEX = "0123456789ABCDEF";

public static String encrypt(String seed, String cleartext) throws Exception {

byte[] rawKey = getRawKey(seed.getBytes()); byte[] result = encrypt(rawKey, cleartext.getBytes());

return toHex(result); }

public static String decrypt(String seed, String encrypted) throws Exception {

byte[] rawKey = getRawKey(seed.getBytes()); byte[] enc = toByte(encrypted);

byte[] result = decrypt(rawKey, enc); return new String(result);

} private static byte[] getRawKey(byte[] seed) throws Exception {

KeyGenerator kgen = KeyGenerator.getInstance("AES"); SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");

sr.setSeed(seed); kgen.init(128, sr); // 192 and 256 bits may not be available

SecretKey skey = kgen.generateKey(); byte[] raw = skey.getEncoded();

return raw; }

private static byte[] encrypt(byte[] raw, byte[] clear) throws Exception { SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");

Cipher cipher = Cipher.getInstance("AES"); cipher.init(Cipher.ENCRYPT_MODE, skeySpec);

byte[] encrypted = cipher.doFinal(clear); return encrypted;

} private static byte[] decrypt(byte[] raw, byte[] encrypted)

throws Exception { SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");

Cipher cipher = Cipher.getInstance("AES"); cipher.init(Cipher.DECRYPT_MODE, skeySpec);