This project constitutes a file cloaking utility that provides password-based security of a single file or a single file system archive file (E.g. .tar.gz). The utility is probably most useful in the following situations:

• Storing backups of sensitive information on the Internet
• Transporting sensitive information electronically (E.g. email) or manually (E.g. using a flash drive)

This project is dependent on pycryptodome (preferred) or pycrypto, using:

• Password-based Key Derivation Function version 2 (PBKDF2)
• AES256 data cryptography in Cipher-Block Chaining (CBC) mode
• Hash-based Message Authentication Code (HMAC) function SHA512

Pycryptodome reference: https://www.pycryptodome.org/en/latest/src/api.html Pycrypto reference: https://www.dlitz.net/software/pycrypto/

• Python 3
• pycryptodome (preferred) or pycrypto

Anaconda is not yet addressed. Sorry.

Download the github ZIP file. Unzip it. cd into the master folder. python3 setup.py install

This is NOT commercial software; instead, usage is covered by the GNU General Public License version 3 (2007). In a nutshell, please feel free to use the project and share it as you will but please don't sell it. Thank you!

See the LICENSE file for the GNU licensing information.

from pycloaking import cloak_file, uncloak_file
from os.path import getsize

PASSWORD = "Mary Had a Little Lamb"
CLEARTEXT_FILE_1 = "/etc/hosts"
CIPHERTEXT_FILE = "/tmp/cloaked"
CLEARTEXT_FILE_2 = "/tmp/uncloaked.txt"
et = cloak_file(PASSWORD, CLEARTEXT_FILE_1, CIPHERTEXT_FILE)
print("cloak_file et=", et)
et = uncloak_file(PASSWORD, CIPHERTEXT_FILE, CLEARTEXT_FILE_2)
print("uncloak_file et=", et)
filesize1 = getsize(CLEARTEXT_FILE_1)
print("Original file size ", filesize1)
cloakedsize = getsize(CIPHERTEXT_FILE)
print("Cloaked file size ", cloakedsize)
filesize2 = getsize(CLEARTEXT_FILE_2)
print("Uncloaked file size ", filesize2)    

The API is explained in api_doc.txt.

The ciphertext file created by cloak_file() has the following layout:

TIFF prefix to make the file appear as a TIFF (112 bytes)
Initialization Vector (16 bytes)
Original file size as a binary Little Endian Unsigned Long Long (8 bytes)
"BOUNDARY" as a Python bytearray (8 bytes)
Encrypted file data 
    (last cleartext block was padded if necessary to an 8-byte boundary)
HMAC bytearray (64 bytes)
==========================
Total overhead = 208 bytes

Feel free to add an issue for inquiries and bugs. I'll respond as soon as I can.

Richard Elkins

Dallas, Texas, USA, 3rd Rock, Sol, ...