tox encrypt save

src/toxencryptsave.py

@@ -1,15 +1,93 @@
 import libtox
 import util
+from ctypes import c_void_p, c_size_t, create_string_buffer, byref, c_int, ArgumentError
 
 
-# TODO: add enums and methods
+TOX_ERR_ENCRYPTION = {
+    # The function returned successfully.
+    'OK': 0,
+    # Some input data, or maybe the output pointer, was null.
+    'NULL': 1,
+    # The crypto lib was unable to derive a key from the given passphrase, which is usually a lack of memory issue. The
+    # functions accepting keys do not produce this error.
+    'KEY_DERIVATION_FAILED': 2,
+    # The encryption itself failed.
+    'FAILED': 3
+}
+
+TOX_ERR_DECRYPTION = {
+    # The function returned successfully.
+    'OK': 0,
+    # Some input data, or maybe the output pointer, was null.
+    'NULL': 1,
+    # The input data was shorter than TOX_PASS_ENCRYPTION_EXTRA_LENGTH bytes
+    'INVALID_LENGTH': 2,
+    # The input data is missing the magic number (i.e. wasn't created by this module, or is corrupted)
+    'BAD_FORMAT': 3,
+    # The crypto lib was unable to derive a key from the given passphrase, which is usually a lack of memory issue. The
+    # functions accepting keys do not produce this error.
+    'KEY_DERIVATION_FAILED': 4,
+    # The encrypted byte array could not be decrypted. Either the data was corrupt or the password/key was incorrect.
+    'FAILED': 5,
+}
+
+TOX_PASS_ENCRYPTION_EXTRA_LENGTH = 80
+
 
 class LibToxEncryptSave(util.Singleton):
 
     libtoxencryptsave = libtox.LibToxEncryptSave()
 
-    def __init__(self, password=''):
-        self._password = password
+    def __init__(self, passphrase=''):
+        self._passphrase = passphrase
 
-    def set_password(self, value):
-        self._password = value
+    def set_password(self, passphrase):
+        self._passphrase = passphrase
+
+    def pass_encrypt(self, data):
+        """
+        Encrypts the given data with the given passphrase.
+
+        :return: output array
+        """
+        out = create_string_buffer(len(data) + TOX_PASS_ENCRYPTION_EXTRA_LENGTH)
+        tox_err_encryption = c_int()
+        self.libtoxencryptsave.tox_pass_encrypt(c_void_p(data), c_size_t(len(data)), c_void_p(self._passphrase),
+                                                c_size_t(len(self._passphrase)), out, byref(tox_err_encryption))
+        tox_err_encryption = tox_err_encryption.value
+        if tox_err_encryption == TOX_ERR_ENCRYPTION['OK']:
+            return out
+        elif tox_err_encryption == TOX_ERR_ENCRYPTION['NULL']:
+            raise ArgumentError('Some input data, or maybe the output pointer, was null.')
+        elif tox_err_encryption == TOX_ERR_ENCRYPTION['KEY_DERIVATION_FAILED']:
+            raise RuntimeError('The crypto lib was unable to derive a key from the given passphrase, which is usually a'
+                               ' lack of memory issue. The functions accepting keys do not produce this error.')
+        elif tox_err_encryption == TOX_ERR_ENCRYPTION['FAILED']:
+            raise RuntimeError('The encryption itself failed.')
+
+    def pass_decrypt(self, data):
+        """
+        Decrypts the given data with the given passphrase.
+
+        :return: output array
+        """
+        out = create_string_buffer(len(data) - TOX_PASS_ENCRYPTION_EXTRA_LENGTH)
+        tox_err_decryption = c_int()
+        self.libtoxencryptsave.tox_pass_encrypt(c_void_p(data), c_size_t(len(data)), c_void_p(self._passphrase),
+                                                c_size_t(len(self._passphrase)), out, byref(tox_err_decryption))
+        tox_err_decryption = tox_err_decryption.value
+        if tox_err_decryption == TOX_ERR_DECRYPTION['OK']:
+            return out
+        elif tox_err_decryption == TOX_ERR_DECRYPTION['NULL']:
+            raise ArgumentError('Some input data, or maybe the output pointer, was null.')
+        elif tox_err_decryption == TOX_ERR_DECRYPTION['INVALID_LENGTH']:
+            raise ArgumentError('The input data was shorter than TOX_PASS_ENCRYPTION_EXTRA_LENGTH bytes')
+        elif tox_err_decryption == TOX_ERR_DECRYPTION['BAD_FORMAT']:
+            raise ArgumentError('The input data is missing the magic number (i.e. wasn\'t created by this module, or is'
+                                ' corrupted)')
+        elif tox_err_decryption == TOX_ERR_DECRYPTION['KEY_DERIVATION_FAILED']:
+            raise RuntimeError('The crypto lib was unable to derive a key from the given passphrase, which is usually a'
+                               ' lack of memory issue. The functions accepting keys do not produce this error.')
+        elif tox_err_decryption == TOX_ERR_DECRYPTION['FAILED']:
+            raise RuntimeError('The encrypted byte array could not be decrypted. Either the data was corrupt or the '
+                               'password/key was incorrect.')