diff --git a/src/toxencryptsave.py b/src/toxencryptsave.py index 5fb4dc0..ef6826d 100644 --- a/src/toxencryptsave.py +++ b/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.')