Android实现AES加密/解密代码
jopen
9年前
import java.security.SecureRandom; import javax.crypto.Cipher; import javax.crypto.KeyGenerator; import javax.crypto.SecretKey; import javax.crypto.spec.IvParameterSpec; import javax.crypto.spec.SecretKeySpec; import android.app.Activity; import android.os.Bundle; import android.util.Log; import android.view.Menu; import android.view.MenuItem; public class MainActivity extends Activity { private static final String TAG = "MainActivity"; 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", "Crypto"); sr.setSeed(seed); kgen.init(128, sr); 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, new IvParameterSpec( new byte[cipher.getBlockSize()])); 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, new IvParameterSpec( new byte[cipher.getBlockSize()])); byte[] decrypted = cipher.doFinal(encrypted); return decrypted; } private static String toHex(String txt) { return toHex(txt.getBytes()); } private static String fromHex(String hex) { return new String(toByte(hex)); } private static byte[] toByte(String hexString) { int len = hexString.length() / 2; byte[] result = new byte[len]; for (int i = 0; i < len; i++) result[i] = Integer.valueOf(hexString.substring(2 * i, 2 * i + 2), 16).byteValue(); return result; } private static String toHex(byte[] buf) { if (buf == null) return ""; StringBuffer result = new StringBuffer(2 * buf.length); for (int i = 0; i < buf.length; i++) { appendHex(result, buf[i]); } return result.toString(); } private final static String HEX = "0123456789ABCDEF"; private static void appendHex(StringBuffer sb, byte b) { sb.append(HEX.charAt((b >> 4) & 0x0f)).append(HEX.charAt(b & 0x0f)); } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); String masterPassword = "key"; String originalText = "0123456789"; try { String encryptingCode = MainActivity.encrypt(masterPassword, originalText); Log.e(TAG, "加密后: " + encryptingCode); String decryptingCode = MainActivity.decrypt(masterPassword, encryptingCode); Log.e(TAG, "解密后: " + decryptingCode); } catch (Exception e) { e.printStackTrace(); } } }