py-it-crypto 1.0.0

E2EE for the inverse transparency toolchain

Py-It-Crypto

This python package implements E2EE encryption functionality for the inverse transparency toolchain [1]. It was developed in the scope of my master thesis at TUM. It is fully compatible with the corresponding Typescript library ts-it-crypto and Golang library go-it-crypto. The module was published to the python package index.

For a detailed description of the implemented protocol, security considerations and software architecture have a look to the thesis.

Installation

To use the go-it-crypto module you can install it with: pip install py-it-crypto

Usage

The functionality of this library requires a function that resolves the identity of users to a RemoteUser object. This objects holds the public keys of a user. This function is mandatory for decryption since it dynamically resolves the identities to the cryptographic keys of a user. This function needs to implement the following signature: RemoteUser fetchUser(string)

Assuming pub_A and priv_A are PEM-encoded public/private keys of a user, the following code initializes the it-crypto library for the owner of this keypair.

it_crypto = ItCrypto(fetch_sender)
it_crypto.login(owner.id, pub_A, pub_A, priv_A, priv_A)

The logged-in user can sign AccessLogs:

signedLog = it_crypto.sign_access_log(access_log)

The logged-in user can encrypt SignedAccessLogs for other users:

cipher = it_crypto.encrypt(singed_log, [receiver1, receiver2])

The logged-in user can decrypt tokens (this only succeeds if this user was specified as receiver during encryption):

received_signed_log = it_crypto.decrypt(cipher)
received_access_log = received_signed_log.extract()

Development

Running static analysis

Make sure you are in the root directory of this repo. Then simply run mypy .

Running tests

Make sure you are in the root directory of this repo. Then simply run pytest .

Build and Upload package

Build

python3 -m build

Upload Package to test.pypi

python3 -m twine upload --repository testpypi dist/py_it_crypto-0.0.1*