abstract WrappingData buildWrappingCipher()

in src/main/java/com/amazonaws/encryptionsdk/internal/JceKeyCipher.java [66:109]
28 lines of code
3 McCabe index (conditional complexity)

  abstract WrappingData buildWrappingCipher(Key key, Map<String, String> encryptionContext)
      throws GeneralSecurityException;

  abstract Cipher buildUnwrappingCipher(
      Key key, byte[] extraInfo, int offset, Map<String, String> encryptionContext)
      throws GeneralSecurityException;

  /**
   * Encrypts the given key, incorporating the given keyName and encryptionContext.
   *
   * @param key The key to encrypt.
   * @param keyName A UTF-8 encoded representing a name for the key.
   * @param keyNamespace A UTF-8 encoded value that namespaces the key.
   * @param encryptionContext A key-value mapping of arbitrary, non-secret, UTF-8 encoded strings
   *     used during encryption and decryption to provide additional authenticated data (AAD).
   * @return The encrypted data key.
   */
  public EncryptedDataKey encryptKey(
      final byte[] key,
      final String keyName,
      final String keyNamespace,
      final Map<String, String> encryptionContext) {

    final byte[] keyNameBytes = keyName.getBytes(KEY_NAME_ENCODING);

    try {
      final JceKeyCipher.WrappingData wData = buildWrappingCipher(wrappingKey, encryptionContext);
      final Cipher cipher = wData.cipher;
      final byte[] encryptedKey = cipher.doFinal(key);

      final byte[] provInfo;
      if (wData.extraInfo.length == 0) {
        provInfo = keyNameBytes;
      } else {
        provInfo = new byte[keyNameBytes.length + wData.extraInfo.length];
        System.arraycopy(keyNameBytes, 0, provInfo, 0, keyNameBytes.length);
        System.arraycopy(wData.extraInfo, 0, provInfo, keyNameBytes.length, wData.extraInfo.length);
      }

      return new KeyBlob(keyNamespace, provInfo, encryptedKey);
    } catch (final GeneralSecurityException gsex) {
      throw new AwsCryptoException(gsex);
    }
  }