Welcome to PySETO

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)
  • Version 4: Sodium Modern
    • ✅ Local: Symmetric Authenticated Encryption
      • XChaCha20 + BLAKE2b-MAC (Encrypt-then-MAC).

    • ✅ Public: Asymmetric Authentication (Public-Key Signatures)
      • EdDSA over Curve25519.

You can install PySETO with pip:

$ pip install pyseto

And then, you can use it as follows:

v4.local

>>> import pyseto
>>> from pyseto import Key
>>> key = Key.new("v4", "local", "our-secret")
>>> token = pyseto.encode(
...     key, '{"data": "this is a signed message", "exp": "2022-01-01T00:00:00+00:00"}'
... )
>>> token
b'v4.local.VXJUUePf8zL1670zhOmbO7eRdccapuXlf76fRCkntiRauk2qQFOaBQOk4ISSRXQZvcGG2C5H74ShLzoU3YorK4xdfjHBj4ESoRB5mt1FWf8MEXoDQiIHQ4WDyMR57ferhaKJM6FwgcwM2xINWy1xCSFz5f7al0c8RUnd4xO_42beR83ye0jRYg'
>>> decoded = pyseto.decode(key, token)
>>> decoded.payload
b'{"data": "this is a signed message", "exp": "2022-01-01T00:00:00+00:00"}'

v4.public

>>> import pyseto
>>> from pyseto import Key
>>> secret_key_pem = "-----BEGIN PRIVATE KEY-----\nMC4CAQAwBQYDK2VwBCIEILTL+0PfTOIQcn2VPkpxMwf6Gbt9n4UEFDjZ4RuUKjd0\n-----END PRIVATE KEY-----"
>>> public_key_pem = "-----BEGIN PUBLIC KEY-----\nMCowBQYDK2VwAyEAHrnbu7wEfAP9cGBOAHHwmH4Wsot1ciXBHwBBXQ4gsaI=\n-----END PUBLIC KEY-----"
>>> secret_key = Key.new("v4", "public", secret_key_pem)
>>> token = pyseto.encode(
...     secret_key,
...     '{"data": "this is a signed message", "exp": "2022-01-01T00:00:00+00:00"}',
... )
>>> token
B'v4.public.eyJkYXRhIjogInRoaXMgaXMgYSBzaWduZWQgbWVzc2FnZSIsICJleHAiOiAiMjAyMi0wMS0wMVQwMDowMDowMCswMDowMCJ9l1YiKei2FESvHBSGPkn70eFO1hv3tXH0jph1IfZyEfgm3t1DjkYqD5r4aHWZm1eZs_3_bZ9pBQlZGp0DPSdzDg'
>>> public_key = Key.new("v4", "public", public_key_pem)
>>> decoded = pyseto.decode(public_key, token)
>>> decoded.payload
B'{"data": "this is a signed message", "exp": "2022-01-01T00:00:00+00:00"}'