toxygen/src/toxencryptsave.py
2016-05-15 17:39:49 +03:00

111 lines
5.1 KiB
Python

import libtox
import util
from ctypes import c_size_t, create_string_buffer, byref, c_int, ArgumentError, c_char_p, c_bool
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):
self._passphrase = None
def set_password(self, passphrase):
self._passphrase = passphrase
def has_password(self):
return bool(self._passphrase)
def is_data_encrypted(self, data):
func = self.libtoxencryptsave.tox_is_data_encrypted
func.restype = c_bool
result = func(c_char_p(data))
return result
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_char_p(data),
c_size_t(len(data)),
c_char_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_decrypt(c_char_p(data),
c_size_t(len(data)),
c_char_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.')