pyseto 0.7.1

A Python implementation of PASETO (Platfrom-Agnostic Security Tokens).

PySETO - A Python implementation of PASETO

PySETO is a PASETO (Platform-Agnostic SEcurity TOkens) implementation written in Python which supports all of the versions and purposes below.

• Version 1: NIST Compatibility
  • ✅ Local: Symmetric Authenticated Encryption
    • AES-256-CTR + HMAC-SHA384 (Encrypt-then-MAC).
  • ✅ Public: Asymmetric Authentication (Public-Key Signatures)
    • RSASSA-PSS with 2048-bit key, SHA384 hashing and MGF1+SHA384.
• Version 2: Sodium Original
  • ✅ Local: Symmetric Authenticated Encryption
    • XChaCha20-Poly1305 (192-bit nonce, 256-bit key, 128-bit authentication tag).
  • ✅ Public: Asymmetric Authentication (Public-Key Signatures)
    • EdDSA over Curve25519.
• Version 3: NIST Modern
  • ✅ Local: Symmetric Authenticated Encryption
    • AES-256-CTR + HMAC-SHA384 (Encrypt-then-MAC).
  • ✅ Public: Asymmetric Authentication (Public-Key Signatures)
    • ECDSA over NIST P-384, with SHA-384, using RFC 6979 deterministic k-values.
• Version 4: Sodium Modern
  • ✅ Local: Symmetric Authenticated Encryption
    • XChaCha20 + BLAKE2b-MAC (Encrypt-then-MAC).
  • ✅ Public: Asymmetric Authentication (Public-Key Signatures)
    • EdDSA over Curve25519.

In addition, PySETO also supports PASERK (Platform-Agnostic Serialized Keys).

See Document for details.

Installation

You can install PySETO with pip:

$ pip install pyseto

Usage

You can use it as follows:

v4.public

v4.public is one of current PASETO versions to be used for asymmetric authentication (public key signatures).

import pyseto
from pyseto import Key

private_key_pem = b"-----BEGIN PRIVATE KEY-----\nMC4CAQAwBQYDK2VwBCIEILTL+0PfTOIQcn2VPkpxMwf6Gbt9n4UEFDjZ4RuUKjd0\n-----END PRIVATE KEY-----"
public_key_pem = b"-----BEGIN PUBLIC KEY-----\nMCowBQYDK2VwAyEAHrnbu7wEfAP9cGBOAHHwmH4Wsot1ciXBHwBBXQ4gsaI=\n-----END PUBLIC KEY-----"

private_key = Key.new(version=4, type="public", key=private_key_pem)
token = pyseto.encode(private_key, b'{"data": "this is a signed message", "exp": "2022-01-01T00:00:00+00:00"}')

public_key = Key.new(version=4, type="public", key=public_key_pem)
decoded = pyseto.decode(public_key, token)

assert token == b'v4.public.eyJkYXRhIjogInRoaXMgaXMgYSBzaWduZWQgbWVzc2FnZSIsICJleHAiOiAiMjAyMi0wMS0wMVQwMDowMDowMCswMDowMCJ9l1YiKei2FESvHBSGPkn70eFO1hv3tXH0jph1IfZyEfgm3t1DjkYqD5r4aHWZm1eZs_3_bZ9pBQlZGp0DPSdzDg'
assert decoded.payload == b'{"data": "this is a signed message", "exp": "2022-01-01T00:00:00+00:00"}'

v4.local

v4.local is one of current PASETO versions to be used for symmetric authenticated encryption.

import pyseto
from pyseto import Key

key = Key.new(version=4, type="local", key=b"our-secret")
token = pyseto.encode(key, b'{"data": "this is a signed message", "exp": "2022-01-01T00:00:00+00:00"}')

decoded = pyseto.decode(key, token)
assert decoded.payload == b'{"data": "this is a signed message", "exp": "2022-01-01T00:00:00+00:00"}'

PASERK

As shown in the examples above, the pyseto.Key used for encryption and signature can be generated from PASERK or converted to PASERK (or PASERK ID) as follow:

import pyseto
from pyseto import Key

# pyseto.Key can be generated from PASERK.
private_key = Key.from_paserk("k4.secret.tMv7Q99M4hByfZU-SnEzB_oZu32fhQQUONnhG5QqN3Q")
public_key = Key.from_paserk("k4.public.Hrnbu7wEfAP9cGBOAHHwmH4Wsot1ciXBHwBBXQ4gsaI")

token = pyseto.encode(private_key, b'{"data": "this is a signed message", "exp": "2022-01-01T00:00:00+00:00"}')
decoded = pyseto.decode(public_key, token)

assert decoded.payload == b'{"data": "this is a signed message", "exp": "2022-01-01T00:00:00+00:00"}'

# PASERK can be derived from pyseto.Key.
assert private_key.to_paserk() == "k4.secret.tMv7Q99M4hByfZU-SnEzB_oZu32fhQQUONnhG5QqN3Qeudu7vAR8A_1wYE4AcfCYfhayi3VyJcEfAEFdDiCxog"
assert public_key.to_paserk() == "k4.public.Hrnbu7wEfAP9cGBOAHHwmH4Wsot1ciXBHwBBXQ4gsaI"

# PASERK ID can also be derived from pyseto.Key.
assert private_key.to_paserk_id() == "k4.sid.9gZFsAQuXhu9lif2pV3rCDjOewsMF4qb4RHGhc0zUklt"
assert public_key.to_paserk_id() == "k4.pid.yh4-bJYjOYAG6CWy0zsfPmpKylxS7uAWrxqVmBN2KAiJ"

API Reference

See Document.

Tests

You can run tests from the project root after cloning with:

$ tox