以下代码可能会对您有所帮助。使用此工具，您可以在PHP和Android之间加密/解密字符串。
Java部分：
import java.security.NoSuchAlgorithmException;import javax.crypto.Cipher;import javax.crypto.NoSuchPaddingException;import javax.crypto.spec.IvParameterSpec;import javax.crypto.spec.SecretKeySpec;public class MCrypt { private String iv = "fedcba9876543210";//Dummy iv (CHANGE IT!) private IvParameterSpec ivspec; private SecretKeySpec keyspec; private Cipher cipher; private String SecretKey = "0123456789abcdef";//Dummy secretKey (CHANGE IT!) public MCrypt() { ivspec = new IvParameterSpec(iv.getBytes()); keyspec = new SecretKeySpec(SecretKey.getBytes(), "AES"); try { cipher = Cipher.getInstance("AES/CBC/NoPadding"); } catch (NoSuchAlgorithmException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (NoSuchPaddingException e) { // TODO Auto-generated catch block e.printStackTrace(); } } public byte[] encrypt(String text) throws Exception { if(text == null || text.length() == 0) throw new Exception("Empty string"); byte[] encrypted = null; try { cipher.init(Cipher.ENCRYPT_MODE, keyspec, ivspec); encrypted = cipher.doFinal(padString(text).getBytes()); } catch (Exception e) { throw new Exception("[encrypt] " + e.getMessage()); } return encrypted; } public byte[] decrypt(String pre) throws Exception { if(pre == null || pre.length() == 0) throw new Exception("Empty string"); byte[] decrypted = null; try { cipher.init(Cipher.DECRYPT_MODE, keyspec, ivspec); decrypted = cipher.doFinal(hexToBytes(pre)); } catch (Exception e) { throw new Exception("[decrypt] " + e.getMessage()); } return decrypted; } public static String bytesToHex(byte[] data) { if (data==null) { return null; } int len = data.length; String str = ""; for (int i=0; i<len; i++) { if ((data[i]&0xFF)<16) str = str + "0" + java.lang.Integer.toHexString(data[i]&0xFF); else str = str + java.lang.Integer.toHexString(data[i]&0xFF); } return str; } public static byte[] hexToBytes(String str) { if (str==null) { return null; } else if (str.length() < 2) { return null; } else { int len = str.length() / 2; byte[] buffer = new byte[len]; for (int i=0; i<len; i++) { buffer[i] = (byte) Integer.parseInt(str.substring(i*2,i*2+2),16); } return buffer; } } private static String padString(String source) { char paddingChar = ' '; int size = 16; int x = source.length() % size; int padLength = size - x; for (int i = 0; i < padLength; i++) { source += paddingChar; } return source; }}PHP部分：
<?phpclass MCrypt{ private $iv = 'fedcba9876543210'; #Same as in JAVA private $key = '0123456789abcdef'; #Same as in JAVA function __construct() { } function encrypt($str) { //$key = $this->hex2bin($key); $iv = $this->iv; $td = mcrypt_module_open('rijndael-128', '', 'cbc', $iv); mcrypt_generic_init($td, $this->key, $iv); $encrypted = mcrypt_generic($td, $str); mcrypt_generic_deinit($td); mcrypt_module_close($td); return bin2hex($encrypted); } function decrypt($pre) { //$key = $this->hex2bin($key); $pre = $this->hex2bin($pre); $iv = $this->iv; $td = mcrypt_module_open('rijndael-128', '', 'cbc', $iv); mcrypt_generic_init($td, $this->key, $iv); $decrypted = mdecrypt_generic($td, $pre); mcrypt_generic_deinit($td); mcrypt_module_close($td); return utf8_enpre(trim($decrypted)); } protected function hex2bin($hexdata) { $bindata = ''; for ($i = 0; $i < strlen($hexdata); $i += 2) { $bindata .= chr(hexdec(substr($hexdata, $i, 2))); } return $bindata; }}用法（Java）：
mcrypt = new MCrypt();String encrypted = MCrypt.bytesToHex( mcrypt.encrypt("Text to Encrypt") );String decrypted = new String( mcrypt.decrypt( encrypted ) );用法（PHP）：
$mcrypt = new MCrypt();#Encrypt$encrypted = $mcrypt->encrypt("Text to encrypt");#Decrypt$decrypted = $mcrypt->decrypt($encrypted);
