CryptUtils.java

   1 package be.nikiroo.utils;
   2
   3 import java.io.IOException;
   4 import java.io.InputStream;
   5 import java.io.OutputStream;
   6 import java.io.UnsupportedEncodingException;
   7 import java.security.InvalidKeyException;
   8
   9 import javax.crypto.BadPaddingException;
  10 import javax.crypto.Cipher;
  11 import javax.crypto.CipherInputStream;
  12 import javax.crypto.CipherOutputStream;
  13 import javax.crypto.IllegalBlockSizeException;
  14 import javax.crypto.spec.IvParameterSpec;
  15 import javax.crypto.spec.SecretKeySpec;
  16 import javax.net.ssl.SSLException;
  17
  18 import be.nikiroo.utils.streams.Base64InputStream;
  19 import be.nikiroo.utils.streams.Base64OutputStream;
  20
  21 /**
  22  * Small utility class to do AES encryption/decryption.
  23  * <p>
  24  * It is multi-thread compatible, but beware:
  25  * <ul>
  26  * <li>The encrypt/decrypt calls are serialized</li>
  27  * <li>The streams are independent (and thus parallel)</li>
  28  * </ul>
  29  * <p>
  30  * Do not assume it is secure; it just here to offer a more-or-less protected
  31  * exchange of data because anonymous and self-signed certificates backed SSL is
  32  * against Google wishes, and I need Android support.
  33  *
  34  * @author niki
  35  */
  36 public class CryptUtils {
  37         static private final String AES_NAME = "AES/CFB128/NoPadding";
  38
  39         private Cipher ecipher;
  40         private Cipher dcipher;
  41         private byte[] bytes32;
  42
  43         /**
  44          * Small and lazy-easy way to initialize a 128 bits key with
  45          * {@link CryptUtils}.
  46          * <p>
  47          * <b>Some</b> part of the key will be used to generate a 128 bits key and
  48          * initialize the {@link CryptUtils}; even NULL will generate something.
  49          * <p>
  50          * <b>This is most probably not secure. Do not use if you actually care
  51          * about security.</b>
  52          *
  53          * @param key
  54          *            the {@link String} to use as a base for the key, can be NULL
  55          */
  56         public CryptUtils(String key) {
  57                 try {
  58                         init(key2key(key));
  59                 } catch (InvalidKeyException e) {
  60                         // We made sure that the key is correct, so nothing here
  61                         e.printStackTrace();
  62                 }
  63         }
  64
  65         /**
  66          * Create a new instance of {@link CryptUtils} with the given 128 bits key.
  67          * <p>
  68          * The key <b>must</b> be exactly 128 bits long.
  69          *
  70          * @param bytes32
  71          *            the 128 bits (32 bytes) of the key
  72          *
  73          * @throws InvalidKeyException
  74          *             if the key is not an array of 128 bits
  75          */
  76         public CryptUtils(byte[] bytes32) throws InvalidKeyException {
  77                 init(bytes32);
  78         }
  79
  80         /**
  81          * Wrap the given {@link InputStream} so it is transparently encrypted by
  82          * the current {@link CryptUtils}.
  83          *
  84          * @param in
  85          *            the {@link InputStream} to wrap
  86          * @return the auto-encode {@link InputStream}
  87          */
  88         public InputStream encrypt(InputStream in) {
  89                 Cipher ecipher = newCipher(Cipher.ENCRYPT_MODE);
  90                 return new CipherInputStream(in, ecipher);
  91         }
  92
  93         /**
  94          * Wrap the given {@link InputStream} so it is transparently encrypted by
  95          * the current {@link CryptUtils} and encoded in base64.
  96          *
  97          * @param in
  98          *            the {@link InputStream} to wrap
  99          *
 100          * @return the auto-encode {@link InputStream}
 101          *
 102          * @throws IOException
 103          *             in case of I/O error
 104          */
 105         public InputStream encrypt64(InputStream in) throws IOException {
 106                 return new Base64InputStream(encrypt(in), true);
 107         }
 108
 109         /**
 110          * Wrap the given {@link OutputStream} so it is transparently encrypted by
 111          * the current {@link CryptUtils}.
 112          *
 113          * @param out
 114          *            the {@link OutputStream} to wrap
 115          *
 116          * @return the auto-encode {@link OutputStream}
 117          */
 118         public OutputStream encrypt(OutputStream out) {
 119                 Cipher ecipher = newCipher(Cipher.ENCRYPT_MODE);
 120                 return new CipherOutputStream(out, ecipher);
 121         }
 122
 123         /**
 124          * Wrap the given {@link OutputStream} so it is transparently encrypted by
 125          * the current {@link CryptUtils} and encoded in base64.
 126          *
 127          * @param out
 128          *            the {@link OutputStream} to wrap
 129          *
 130          * @return the auto-encode {@link OutputStream}
 131          *
 132          * @throws IOException
 133          *             in case of I/O error
 134          */
 135         public OutputStream encrypt64(OutputStream out) throws IOException {
 136                 return encrypt(new Base64OutputStream(out, true));
 137         }
 138
 139         /**
 140          * Wrap the given {@link OutputStream} so it is transparently decoded by the
 141          * current {@link CryptUtils}.
 142          *
 143          * @param in
 144          *            the {@link InputStream} to wrap
 145          *
 146          * @return the auto-decode {@link InputStream}
 147          */
 148         public InputStream decrypt(InputStream in) {
 149                 Cipher dcipher = newCipher(Cipher.DECRYPT_MODE);
 150                 return new CipherInputStream(in, dcipher);
 151         }
 152
 153         /**
 154          * Wrap the given {@link OutputStream} so it is transparently decoded by the
 155          * current {@link CryptUtils} and decoded from base64.
 156          *
 157          * @param in
 158          *            the {@link InputStream} to wrap
 159          *
 160          * @return the auto-decode {@link InputStream}
 161          *
 162          * @throws IOException
 163          *             in case of I/O error
 164          */
 165         public InputStream decrypt64(InputStream in) throws IOException {
 166                 return decrypt(new Base64InputStream(in, false));
 167         }
 168
 169         /**
 170          * Wrap the given {@link OutputStream} so it is transparently decoded by the
 171          * current {@link CryptUtils}.
 172          *
 173          * @param out
 174          *            the {@link OutputStream} to wrap
 175          * @return the auto-decode {@link OutputStream}
 176          */
 177         public OutputStream decrypt(OutputStream out) {
 178                 Cipher dcipher = newCipher(Cipher.DECRYPT_MODE);
 179                 return new CipherOutputStream(out, dcipher);
 180         }
 181
 182         /**
 183          * Wrap the given {@link OutputStream} so it is transparently decoded by the
 184          * current {@link CryptUtils} and decoded from base64.
 185          *
 186          * @param out
 187          *            the {@link OutputStream} to wrap
 188          *
 189          * @return the auto-decode {@link OutputStream}
 190          *
 191          * @throws IOException
 192          *             in case of I/O error
 193          */
 194         public OutputStream decrypt64(OutputStream out) throws IOException {
 195                 return new Base64OutputStream(decrypt(out), false);
 196         }
 197
 198         /**
 199          * This method required an array of 128 bits.
 200          *
 201          * @param bytes32
 202          *            the array, which <b>must</b> be of 128 bits (32 bytes)
 203          *
 204          * @throws InvalidKeyException
 205          *             if the key is not an array of 128 bits (32 bytes)
 206          */
 207         private void init(byte[] bytes32) throws InvalidKeyException {
 208                 if (bytes32 == null || bytes32.length != 32) {
 209                         throw new InvalidKeyException(
 210                                         "The size of the key must be of 128 bits (32 bytes), it is: "
 211                                                         + (bytes32 == null ? "null" : "" + bytes32.length)
 212                                                         + " bytes");
 213                 }
 214
 215                 this.bytes32 = bytes32;
 216                 this.ecipher = newCipher(Cipher.ENCRYPT_MODE);
 217                 this.dcipher = newCipher(Cipher.DECRYPT_MODE);
 218         }
 219
 220         /**
 221          * Create a new {@link Cipher}of the given mode (see
 222          * {@link Cipher#ENCRYPT_MODE} and {@link Cipher#ENCRYPT_MODE}).
 223          *
 224          * @param mode
 225          *            the mode ({@link Cipher#ENCRYPT_MODE} or
 226          *            {@link Cipher#ENCRYPT_MODE})
 227          *
 228          * @return the new {@link Cipher}
 229          */
 230         private Cipher newCipher(int mode) {
 231                 try {
 232                         // bytes32 = 32 bytes, 32 > 16
 233                         byte[] iv = new byte[16];
 234                         for (int i = 0; i < iv.length; i++) {
 235                                 iv[i] = bytes32[i];
 236                         }
 237                         IvParameterSpec ivspec = new IvParameterSpec(iv);
 238                         Cipher cipher = Cipher.getInstance(AES_NAME);
 239                         cipher.init(mode, new SecretKeySpec(bytes32, "AES"), ivspec);
 240                         return cipher;
 241                 } catch (Exception e) {
 242                         e.printStackTrace();
 243                         throw new RuntimeException(
 244                                         "Cannot initialize encryption sub-system", e);
 245                 }
 246         }
 247
 248         /**
 249          * Encrypt the data.
 250          *
 251          * @param data
 252          *            the data to encrypt
 253          *
 254          * @return the encrypted data
 255          *
 256          * @throws SSLException
 257          *             in case of I/O error (i.e., the data is not what you assumed
 258          *             it was)
 259          */
 260         public byte[] encrypt(byte[] data) throws SSLException {
 261                 synchronized (ecipher) {
 262                         try {
 263                                 return ecipher.doFinal(data);
 264                         } catch (IllegalBlockSizeException e) {
 265                                 throw new SSLException(e);
 266                         } catch (BadPaddingException e) {
 267                                 throw new SSLException(e);
 268                         }
 269                 }
 270         }
 271
 272         /**
 273          * Encrypt the data.
 274          *
 275          * @param data
 276          *            the data to encrypt
 277          *
 278          * @return the encrypted data
 279          *
 280          * @throws SSLException
 281          *             in case of I/O error (i.e., the data is not what you assumed
 282          *             it was)
 283          */
 284         public byte[] encrypt(String data) throws SSLException {
 285                 return encrypt(StringUtils.getBytes(data));
 286         }
 287
 288         /**
 289          * Encrypt the data, then encode it into Base64.
 290          *
 291          * @param data
 292          *            the data to encrypt
 293          * @param zip
 294          *            TRUE to also compress the data in GZIP format; remember that
 295          *            compressed and not-compressed content are different; you need
 296          *            to know which is which when decoding
 297          *
 298          * @return the encrypted data, encoded in Base64
 299          *
 300          * @throws SSLException
 301          *             in case of I/O error (i.e., the data is not what you assumed
 302          *             it was)
 303          */
 304         public String encrypt64(String data) throws SSLException {
 305                 return encrypt64(StringUtils.getBytes(data));
 306         }
 307
 308         /**
 309          * Encrypt the data, then encode it into Base64.
 310          *
 311          * @param data
 312          *            the data to encrypt
 313          *
 314          * @return the encrypted data, encoded in Base64
 315          *
 316          * @throws SSLException
 317          *             in case of I/O error (i.e., the data is not what you assumed
 318          *             it was)
 319          */
 320         public String encrypt64(byte[] data) throws SSLException {
 321                 try {
 322                         return StringUtils.base64(encrypt(data));
 323                 } catch (IOException e) {
 324                         // not exactly true, but we consider here that this error is a crypt
 325                         // error, not a normal I/O error
 326                         throw new SSLException(e);
 327                 }
 328         }
 329
 330         /**
 331          * Decode the data which is assumed to be encrypted with the same utilities.
 332          *
 333          * @param data
 334          *            the encrypted data to decode
 335          *
 336          * @return the original, decoded data
 337          *
 338          * @throws SSLException
 339          *             in case of I/O error
 340          */
 341         public byte[] decrypt(byte[] data) throws SSLException {
 342                 synchronized (dcipher) {
 343                         try {
 344                                 return dcipher.doFinal(data);
 345                         } catch (IllegalBlockSizeException e) {
 346                                 throw new SSLException(e);
 347                         } catch (BadPaddingException e) {
 348                                 throw new SSLException(e);
 349                         }
 350                 }
 351         }
 352
 353         /**
 354          * Decode the data which is assumed to be encrypted with the same utilities
 355          * and to be a {@link String}.
 356          *
 357          * @param data
 358          *            the encrypted data to decode
 359          *
 360          * @return the original, decoded data,as a {@link String}
 361          *
 362          * @throws SSLException
 363          *             in case of I/O error
 364          */
 365         public String decrypts(byte[] data) throws SSLException {
 366                 try {
 367                         return new String(decrypt(data), "UTF-8");
 368                 } catch (UnsupportedEncodingException e) {
 369                         // UTF-8 is required in all conform JVMs
 370                         e.printStackTrace();
 371                         return null;
 372                 }
 373         }
 374
 375         /**
 376          * Decode the data which is assumed to be encrypted with the same utilities
 377          * and is a Base64 encoded value.
 378          *
 379          * @param data
 380          *            the encrypted data to decode in Base64 format
 381          * @param zip
 382          *            TRUE to also uncompress the data from a GZIP format
 383          *            automatically; if set to FALSE, zipped data can be returned
 384          *
 385          * @return the original, decoded data
 386          *
 387          * @throws SSLException
 388          *             in case of I/O error
 389          */
 390         public byte[] decrypt64(String data) throws SSLException {
 391                 try {
 392                         return decrypt(StringUtils.unbase64(data));
 393                 } catch (IOException e) {
 394                         // not exactly true, but we consider here that this error is a crypt
 395                         // error, not a normal I/O error
 396                         throw new SSLException(e);
 397                 }
 398         }
 399
 400         /**
 401          * Decode the data which is assumed to be encrypted with the same utilities
 402          * and is a Base64 encoded value, then convert it into a String (this method
 403          * assumes the data <b>was</b> indeed a UTF-8 encoded {@link String}).
 404          *
 405          * @param data
 406          *            the encrypted data to decode in Base64 format
 407          * @param zip
 408          *            TRUE to also uncompress the data from a GZIP format
 409          *            automatically; if set to FALSE, zipped data can be returned
 410          *
 411          * @return the original, decoded data
 412          *
 413          * @throws SSLException
 414          *             in case of I/O error
 415          */
 416         public String decrypt64s(String data) throws SSLException {
 417                 try {
 418                         return new String(decrypt(StringUtils.unbase64(data)), "UTF-8");
 419                 } catch (UnsupportedEncodingException e) {
 420                         // UTF-8 is required in all conform JVMs
 421                         e.printStackTrace();
 422                         return null;
 423                 } catch (IOException e) {
 424                         // not exactly true, but we consider here that this error is a crypt
 425                         // error, not a normal I/O error
 426                         throw new SSLException(e);
 427                 }
 428         }
 429
 430         /**
 431          * This is probably <b>NOT</b> secure!
 432          *
 433          * @param input
 434          *            some {@link String} input
 435          *
 436          * @return a 128 bits key computed from the given input
 437          */
 438         static private byte[] key2key(String input) {
 439                 return StringUtils.getMd5Hash("" + input).getBytes();
 440         }
 441 }