PySETO - A Python implementation of PASETO/PASERK
PySETO is a PASETO (Platform-Agnostic SEcurity TOkens)/PASERK (Platform-Agnostic Serialized Keys) implementation written in Python
which supports all of the versions (v1,
v2,
v3 and
v4) and purposes (public and local)
and has passed all of the official tests.
You can install PySETO with pip:
$ pip install pysetoPySETO can be used in ease as follows (in case of v4.public):
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-----"
# Create a PASETO token.
private_key = Key.new(version=4, purpose="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"}')
# Decode and verify a PASETO token.
public_key = Key.new(version=4, purpose="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"}'See following contents or Documentation for details.
Index
- Installation
- Supported PASETO Versions
- Supported PASERK Types
- PASETO Usage
- PASERK Usage
- API Reference
- Tests
- Contributing
Installation
You can install PySETO with pip:
$ pip install pysetoSupported PASETO Versions
PySETO supports all of PASETO versions and purposes below:
| v4 | v3 | v2 | v1 | |
|---|---|---|---|---|
local |
||||
public |
Supported PASERK Types
PySETO also supports PASERK (Platform-Agnostic Serialized Keys). Currently, following PASERK types are supported:
| v4 | v3 | v2 | v1 | |
|---|---|---|---|---|
lid |
||||
sid |
||||
pid |
||||
local |
||||
secret |
||||
public |
||||
seal |
||||
local-wrap |
||||
secret-wrap |
||||
local-pw |
||||
secret-pw |
PASETO Usage
By using this PySETO, you can easily create, decode and verify PASETO tokens. Here are sample codes that handle version 4 PySETO tokens.
Please refer to the Documentation for all usage examples including other versions.
Basic usage: 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, purpose="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, purpose="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"}'Basic usage: 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, purpose="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"}'Using serializer/deserializer for payload and footer
By using serializer and deserializer, you can encode/decode a dict-typed payload and footer included in PASETO tokens into an arbitrary format.
The following example shows that the payload and the footer in a PASETO token are encoded/decoded as JSON formatted data.
When specifing dict-typed payload, exp parameter can be used to set the expiration time (seconds) of the token.
import json
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, purpose="public", key=private_key_pem)
public_key = Key.new(version=4, purpose="public", key=public_key_pem)
token = pyseto.encode(
private_key,
{"data": "this is a signed message"},
footer={"kid": public_key.to_paserk_id()},
serializer=json,
exp=3600,
)
decoded = pyseto.decode(public_key, token, deserializer=json)
assert decoded.payload["data"] == "this is a signed message"
assert decoded.payload["exp"] == "2021-11-11T00:00:00+00:00"
assert decoded.footer["kid"] == "k4.pid.yh4-bJYjOYAG6CWy0zsfPmpKylxS7uAWrxqVmBN2KAiJ"Using Paseto class for handling registered claims
By using Paseto class, you can change the default value of exp (the expiration date ot tokens), whether to include an iat claim, and other settings.
Note that pyseto.encode() and pyseto.decode() are aliases to the encode() and decode() of the global "Paseto" class instance created with the default settings.
import json
import pyseto
from pyseto import Key, Paseto
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, purpose="public", key=private_key_pem)
paseto = Paseto.new(exp=3600, include_iat=True) # Default values are exp=0(not specified) and including_iat=False
token = paseto.encode(
private_key,
{"data": "this is a signed message"},
serializer=json,
)
public_key = Key.new(version=4, purpose="public", key=public_key_pem)
decoded = pyseto.decode(public_key, token, deserializer=json)
assert decoded.payload["data"] == "this is a signed message"
assert decoded.payload["iat"] == "2021-11-11T00:00:00+00:00"
assert decoded.payload["exp"] == "2021-11-11T01:00:00+00:00"PASERK Usage
PASERK (Platform-Agnostic Serialized Keys) is an extension to PASETO that provides key-wrapping and serialization.
Serializing/Deserializing PASERK
As shown in the examples above, the pyseto.Key used for encryption and signature can be generated from PASERK or converted to PASERK as follows:
import pyseto
from pyseto import Key
# pyseto.Key can be generated from PASERK.
symmetric_key = Key.new(version=4, purpose="local", key=b"our-secret")
private_key = Key.from_paserk("k4.secret.tMv7Q99M4hByfZU-SnEzB_oZu32fhQQUONnhG5QqN3Qeudu7vAR8A_1wYE4AcfCYfhayi3VyJcEfAEFdDiCxog")
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 symmetric_key.to_paserk() == "k4.local.b3VyLXNlY3JldA"
assert private_key.to_paserk() == "k4.secret.tMv7Q99M4hByfZU-SnEzB_oZu32fhQQUONnhG5QqN3Qeudu7vAR8A_1wYE4AcfCYfhayi3VyJcEfAEFdDiCxog"
assert public_key.to_paserk() == "k4.public.Hrnbu7wEfAP9cGBOAHHwmH4Wsot1ciXBHwBBXQ4gsaI"Serializing PASERK ID
pyseto.Key can also be converted to PASERK ID as follows:
import pyseto
from pyseto import Key
# pyseto.Key can be generated from PASERK.
symmetric_key = Key.new(version=4, purpose="local", key=b"our-secret")
private_key = Key.from_paserk("k4.secret.tMv7Q99M4hByfZU-SnEzB_oZu32fhQQUONnhG5QqN3Qeudu7vAR8A_1wYE4AcfCYfhayi3VyJcEfAEFdDiCxog")
public_key = Key.from_paserk("k4.public.Hrnbu7wEfAP9cGBOAHHwmH4Wsot1ciXBHwBBXQ4gsaI")
# PASERK ID can be derived from pyseto.Key.
assert symmetric_key.to_paserk_id() == "k4.lid._D6kgTzxgiPGk35gMj9bukgj4En2H94u22wVX9zaoh05"
assert private_key.to_paserk() == "k4.secret.tMv7Q99M4hByfZU-SnEzB_oZu32fhQQUONnhG5QqN3Qeudu7vAR8A_1wYE4AcfCYfhayi3VyJcEfAEFdDiCxog"
assert public_key.to_paserk_id() == "k4.pid.yh4-bJYjOYAG6CWy0zsfPmpKylxS7uAWrxqVmBN2KAiJ"Key Wrapping
If you call to_paserk with wrapping_key, you can get a wrapped (encrypted) PASERK with the wrapping key.
The wrapped PASERK can be decrypted by calling from_paserk with wrapping key.
In case of local-wrap.pie:
import pyseto
from pyseto import Key
raw_key = Key.new(version=4, purpose="local", key=b"our-secret")
wrapping_key = token_bytes(32)
wpk = raw_key.to_paserk(wrapping_key=wrapping_key)
token = pyseto.encode(raw_key, b'{"data": "this is a signed message", "exp": "2022-01-01T00:00:00+00:00"}')
unwrapped_key = Key.from_paserk(wpk, wrapping_key=wrapping_key)
decoded = pyseto.decode(unwrapped_key, token)
# assert wpk == "k4.local-wrap.pie.TNKEwC4K1xBcgJ_GiwWAoRlQFE33HJO3oN9DHEZ05pieSCd-W7bgAL64VG9TZ_pBkuNBFHNrfOGHtnfnhYGdbz5-x3CxShhPJxg"
assert decoded.payload == b'{"data": "this is a signed message", "exp": "2022-01-01T00:00:00+00:00"}'In case of secret-wrap.pie:
import pyseto
from pyseto import Key
raw_private_key = Key.from_paserk(
"k4.secret.tMv7Q99M4hByfZU-SnEzB_oZu32fhQQUONnhG5QqN3Qeudu7vAR8A_1wYE4AcfCYfhayi3VyJcEfAEFdDiCxog"
)
wrapping_key = token_bytes(32)
wpk = raw_private_key.to_paserk(wrapping_key=wrapping_key)
unwrapped_private_key = Key.from_paserk(wpk, wrapping_key=wrapping_key)
token = pyseto.encode(unwrapped_private_key, b'{"data": "this is a signed message", "exp": "2022-01-01T00:00:00+00:00"}')
public_key = Key.from_paserk("k4.public.Hrnbu7wEfAP9cGBOAHHwmH4Wsot1ciXBHwBBXQ4gsaI")
decoded = pyseto.decode(public_key, token)
# assert wpk == "k4.secret-wrap.pie.excv7V4-NaECy5hpji-tkSkMvyjsAgNxA-mGALgdjyvGNyDlTb89bJ35R1e3tILgbMpEW5WXMXzySe2T-sBz-ZAcs1j7rbD3ZWvsBTM6K5N9wWfAxbR4ppCXH_H5__9yY-kBaF2NimyAJyduhOhSmqLm6TTSucpAOakEJOXePW8"
assert decoded.payload == b'{"data": "this is a signed message", "exp": "2022-01-01T00:00:00+00:00"}'Password-based Key Encryption
If you call to_paserk with password, you can get a wrapped (encrypted) PASERK with the password.
The wrapped PASERK can be decrypted by calling from_paserk with passwrod.
In case of local-pw:
import pyseto
from pyseto import Key
raw_key = Key.new(version=4, purpose="local", key=b"our-secret")
token = pyseto.encode(raw_key, b'{"data": "this is a signed message", "exp": "2022-01-01T00:00:00+00:00"}')
wpk = raw_key.to_paserk(password="our-secret")
unwrapped_key = Key.from_paserk(wpk, password="our-secret")
decoded = pyseto.decode(unwrapped_key, token)
# assert wpk == "k4.local-pw.HrCs9Pu-2LB0l7jkHB-x2gAAAAAA8AAAAAAAAgAAAAGttW0IHZjQCHJdg-Vc3tqO_GSLR4vzLl-yrKk2I-l8YHj6jWpC0lQB2Z7uzTtVyV1rd_EZQPzHdw5VOtyucP0FkCU"
assert decoded.payload == b'{"data": "this is a signed message", "exp": "2022-01-01T00:00:00+00:00"}'In case of secret-pw:
import pyseto
from pyseto import Key
raw_private_key = Key.from_paserk(
"k4.secret.tMv7Q99M4hByfZU-SnEzB_oZu32fhQQUONnhG5QqN3Qeudu7vAR8A_1wYE4AcfCYfhayi3VyJcEfAEFdDiCxog"
)
wpk = raw_private_key.to_paserk(password="our-secret")
unwrapped_private_key = Key.from_paserk(wpk, password="our-secret")
token = pyseto.encode(unwrapped_private_key, b'{"data": "this is a signed message", "exp": "2022-01-01T00:00:00+00:00"}')
public_key = Key.from_paserk(
"k4.public.Hrnbu7wEfAP9cGBOAHHwmH4Wsot1ciXBHwBBXQ4gsaI"
)
decoded = pyseto.decode(public_key, token)
# assert wpk == "k4.secret-pw.MEMW4K1MaD5nWigCLyEyFAAAAAAA8AAAAAAAAgAAAAFU-tArtryNVjS2n2hCYiM11V6tOyuIog69Bjb0yNZanrLJ3afGclb3kPzQ6IhK8ob9E4QgRdEALGWCizZ0RCPFF_M95IQDfmdYKC0Er656UgKUK4UKG9JlxP4o81UwoJoZYz_D1zTlltipEa5RiNvUtNU8vLKoGSY"
assert decoded.payload == b'{"data": "this is a signed message", "exp": "2022-01-01T00:00:00+00:00"}'Asymmetric Encryption
At this time, PySETO supports asymmetric encryption (key sealing) for v2 and v4.
import pyseto
from pyseto import Key
private_key_pem = b"-----BEGIN PRIVATE KEY-----\nMC4CAQAwBQYDK2VuBCIEIFAF7jSCZHFgWvC8hUkXr55Az6Pot2g4zOAUxck0/6x8\n-----END PRIVATE KEY-----"
public_key_pem = b"-----BEGIN PUBLIC KEY-----\nMCowBQYDK2VuAyEAFv8IXsICYj0paznDK/99GyCsFOIGnfY87ayyNSIvSB4=\n-----END PUBLIC KEY-----"
raw_key = Key.new(version=4, purpose="local", key=b"our-secret")
token = pyseto.encode(
raw_key,
b'{"data": "this is a signed message", "exp": "2022-01-01T00:00:00+00:00"}',
)
sealed_key = raw_key.to_paserk(sealing_key=public_key_pem)
unsealed_key = Key.from_paserk(sealed_key, unsealing_key=private_key_pem)
decoded = pyseto.decode(unsealed_key, token)
assert (
decoded.payload
== b'{"data": "this is a signed message", "exp": "2022-01-01T00:00:00+00:00"}'
)Key searing for v1 and v3 have not been supported yet.
API Reference
See Documentation.
Tests
You can run tests from the project root after cloning with:
$ toxContributing
We welcome all kind of contributions, filing issues, suggesting new features or sending PRs.