def encrypt_file(self, in_file_path, out_file_path, password = None):
#If a password is provided, generate new salt and create key and iv
if password is not None:
self.new_salt()
self.create_key_from_password(password)
else:
self._salt = None
#If key and iv are not provided are established above, bail out.
if self._key is None or self._iv is None:
return False
#Initialize encryption using key and iv
expanded_key = expandKey(self._key)
aes_cipher_256 = AESCipher(expanded_key)
aes_cbc_256 = CBCMode(aes_cipher_256)
aes_cbc_256.set_iv(self._iv)
#Get filesize of original file for storage in encrypted file
try:
filesize = os.stat(in_file_path)[6]
except:
return False
with open(in_file_path, 'rb') as in_file:
with open(out_file_path, 'wb') as out_file:
#Write salt if present
if self._salt is not None:
out_file.write(self._salt)
#Write filesize of original
out_file.write(struct.pack('!L',filesize))
#Encrypt to eof
while 1:
in_data = bytearray(in_file.read(16))
if not in_data:
self._salt = None
return True
else:
while len(in_data) < 16:in_data.append(0)
out_data = aes_cbc_256.encrypt_block(in_data)
out_file.write(fix_bytes(out_data))
