swarmauri_tokens_sshcert

An OpenSSH certificate token service for the Swarmauri framework. This service mints and verifies OpenSSH user and host certificates and exposes no JWKS endpoints.

Usage

SshCertTokenService uses the local ssh-keygen utility to mint and verify OpenSSH certificates. A key provider supplies the certificate authority (CA) key material used for signing. The typical workflow is:

1. implement or configure an IKeyProvider that returns your CA key
2. create the token service
3. mint a certificate for a subject public key
4. verify the certificate before trusting it

import asyncio
import os
import subprocess
import tempfile
from typing import Iterable, Mapping

from swarmauri_tokens_sshcert import SshCertTokenService
from swarmauri_core.crypto.types import ExportPolicy, KeyRef, KeyType, KeyUse
from swarmauri_core.key_providers import IKeyProvider


def _generate_keypair() -> tuple[str, str]:
    with tempfile.TemporaryDirectory() as d:
        path = os.path.join(d, "id")
        subprocess.run(
            ["ssh-keygen", "-t", "ed25519", "-N", "", "-f", path],
            check=True,
            stdout=subprocess.DEVNULL,
            stderr=subprocess.DEVNULL,
        )
        priv = open(path, "r", encoding="utf-8").read()
        pub = open(path + ".pub", "r", encoding="utf-8").read()
    return priv, pub


class DummyKeyProvider(IKeyProvider):
    def __init__(self) -> None:
        self.priv, self.pub = _generate_keypair()
        self.kid = "ca"
        self.version = 1

    async def get_key(
        self, kid: str, version: int | None = None, *, include_secret: bool = False
    ) -> KeyRef:
        material = self.priv if include_secret else None
        return KeyRef(
            kid=self.kid,
            version=self.version,
            type=KeyType.ED25519,
            uses=(KeyUse.SIGN, KeyUse.VERIFY),
            export_policy=ExportPolicy.SECRET_WHEN_ALLOWED,
            material=material,
            public=self.pub,
        )

    async def jwks(self, *, prefix_kids: str | None = None) -> dict:
        return {"keys": []}

    def supports(self) -> Mapping[str, Iterable[str]]:
        return {}


async def main() -> None:
    svc = SshCertTokenService(DummyKeyProvider(), ca_kid="ca")
    _, subj_pub = _generate_keypair()
    cert = await svc.mint(
        {"subject_pub": subj_pub, "principals": ["alice"], "key_id": "demo"},
        alg="ssh-ed25519",
    )
    info = await svc.verify(cert, audience="alice")
    print(info["key_id"])


if __name__ == "__main__":
    asyncio.run(main())

The example above mints a certificate for a generated key and verifies it for the principal alice. The service requires the ssh-keygen command to be available on the system path.

Want to help?

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