A simple Python module that uses the Fernet secure algorithm to encrypt you Python objects with just one line of code.

Installation

Simply install using the Python package manager:

pip install friendlycrypto

Usage

Encrypting bytes

from friendlycrypto import Cryptographer

with open('img.png', 'rb') as original_f:
    # Loads some file in a 'read-bytes' mode.
    original_data = original_f.read()

# Encoding the password string into a bytes-string.
key = input("Key for encryption: ").encode('utf8')

# Encrypt the data usaing the 'Cryptographer' object
grapher = Cryptographer()
encrypted = grapher.encrypt(original_data, key)

with open('img.png.encrypted', 'wb') as encrypted_f:
    # Write the encrypted data back into a new file.
    encrypted_f.write(encrypted)

Encrypting Python objects

from friendlycrypto import FriendlyCryptographer

# The data can be any Python object!
# For this example, we are using a simple dict with strings.
data = {
    'user1': 'password',
    'user2': 'another-password',
}

# Encoding the password string into a bytes-string.
key = input("Key for encryption: ").encode('utf8')

# Encrypt the data usaing the 'FriendlyCryptographer' object
grapher = FriendlyCryptographer()
encrypted = grapher.encrypt(data, key)

with open('data.encrypted', 'wb') as encrypted_f:
    # Write the encrypted data back into a new file.
    encrypted_f.write(encrypted)

Additional arguments

The Cryptographer and FriendlyCryptographer objects share an init method with two additional arguments:

salt: bytes

Should be a bytes-string (recommended to be at least 16 bytes long). Those bytes are added to the encrypted data to add additional randomness and uniqueness to your database. The salt shouldn't be stored with the database. generate using the os.urandom function.

Read more about the salt in hashing.

kdf_iterations: int

The module uses a key derivation function to convert the given password bytes into a fixed-length bytes string. Each iteration of the function takes time to compute, and thus a larger number of iterations makes it harder for attackers to just guess every option.

The recommended and default value is 100_000, and on my computer it takes approximately 0.1 seconds to compute.