PyJWK doesn't support RSA-OAEP algorithm

[flyte]

Using a hosted KeyCloak instance from https://www.cloud-iam.com/ which sets its enc public cert to use RSA-OAEP causes PyJWKClient to throw an exception (raised by PyJWK constructor).

Expected Result

I don't know the ins and outs of it, but either the RSA-OAEP algorithm should be supported or the enc cert ignored (the sig one is RSA256).

Actual Result

Traceback (most recent call last):
  File "/home/flyte/dev/ascender/ascender-api/test.py", line 8, in <module>
    PyJWKSet(certs_from_keycloak["keys"])
  File "/home/flyte/.cache/pypoetry/virtualenvs/ascender-api-35481XGP-py3.10/lib/python3.10/site-packages/jwt/api_jwk.py", line 87, in __init__
    self.keys.append(PyJWK(key))
  File "/home/flyte/.cache/pypoetry/virtualenvs/ascender-api-35481XGP-py3.10/lib/python3.10/site-packages/jwt/api_jwk.py", line 50, in __init__
    raise PyJWKError("Unable to find a algorithm for key: %s" % self._jwk_data)
jwt.exceptions.PyJWKError: Unable to find a algorithm for key: {'kid': 'A2MJgrKnftrPyUXS-FNN4g0spwz1H89gPTAzjb4u91o', 'kty': 'RSA', 'alg': 'RSA-OAEP', 'use': 'enc', 'n': 'xTT6GOIMi7GXWUNQ4ZoFQuHihNVnRxx9Y9hAcvV6ZO-OiT9dcLqVIlhDckf7yVOfitMG_qZkhIzaOBWNWJZK1_zaeFCv_GQPPEVi_JafLUKz6AAaMdqiFuKfDyoAecOJWc0ar4autehQMpuRLh8POMmrnNMLolWqEauYmu_ajT9eA99hcseahDDhPWgGuSc0mFNS5YcjyIaoKfwWWkvtfqKNBEzf_EnbSsAibQWXUvVCRRLSNdCrImdR-FdprpudQs7sTetP5lU2aP0ChpM8GemidA5ZieNdykW1lVi0Sa6R1gkGzhL03LYzaPzgc8RMJQtaZg93EuSQLs66uKM3-w', 'e': 'AQAB', 'x5c': ['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'], 'x5t': 'WAcN3AzixLmWqoKdNhhmxilWhFU', 'x5t#S256': 'M4D1NyJsOrtsjG7tRbDs-zd7hg2tvm9kbYDS4gRO7KI'}

Reproduction Steps

import json

from jwt import PyJWKSet


certs_from_keycloak = json.loads("""{"keys":[{"kid":"JJPd3kTh6QFpJ9P-MSFZbBf43S-LRTAot4DJmwd5EQk","kty":"RSA","alg":"RS256","use":"sig","n":"yluqHNqoRdCqCmhivy_yl4dDDMI5pwg59VMz7dYQREfehxukXPhfchbAHxDhGCZjUYieV4TIRGyEBVR3zQ9ihjStYPz8bXUeWqMBSYaH8R7Xb98GeZplVKnF-OLj0fWJkoNSgPYKuSDm2KXdz2hIZ1jOPKLDqpblnnqxrL_xX-1_kEBWehJmzmS0McCOK2nm7lLWf6zoTBi-bp1x5iNl7qteHdo0UZl1DP4NVE0lYk0uGa-L6ye0pQKS77Ro3R5nURvEO0AcaXYr6wLcxYsPRiYDlOactB6WnRFKAhEgRzdp1a04tH8hquHhrdjTc_ZoZelk6ppd-3ZqGq3jMc7TWw","e":"AQAB","x5c":["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"],"x5t":"dcy5v0xWv0qvgfX3CzbukvB5TlA","x5t#S256":"tyTUdZfGEopkBZ0BYyC8IxvQL5KFCn9-Po0V4ociZiY"},{"kid":"A2MJgrKnftrPyUXS-FNN4g0spwz1H89gPTAzjb4u91o","kty":"RSA","alg":"RSA-OAEP","use":"enc","n":"xTT6GOIMi7GXWUNQ4ZoFQuHihNVnRxx9Y9hAcvV6ZO-OiT9dcLqVIlhDckf7yVOfitMG_qZkhIzaOBWNWJZK1_zaeFCv_GQPPEVi_JafLUKz6AAaMdqiFuKfDyoAecOJWc0ar4autehQMpuRLh8POMmrnNMLolWqEauYmu_ajT9eA99hcseahDDhPWgGuSc0mFNS5YcjyIaoKfwWWkvtfqKNBEzf_EnbSsAibQWXUvVCRRLSNdCrImdR-FdprpudQs7sTetP5lU2aP0ChpM8GemidA5ZieNdykW1lVi0Sa6R1gkGzhL03LYzaPzgc8RMJQtaZg93EuSQLs66uKM3-w","e":"AQAB","x5c":["MIICnzCCAYcCBgF+Q6te9zANBgkqhkiG9w0BAQsFADATMREwDwYDVQQDDAhhc2NlbmRlcjAeFw0yMjAxMTAxMTA1MTFaFw0zMjAxMTAxMTA2NTFaMBMxETAPBgNVBAMMCGFzY2VuZGVyMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAxTT6GOIMi7GXWUNQ4ZoFQuHihNVnRxx9Y9hAcvV6ZO+OiT9dcLqVIlhDckf7yVOfitMG/qZkhIzaOBWNWJZK1/zaeFCv/GQPPEVi/JafLUKz6AAaMdqiFuKfDyoAecOJWc0ar4autehQMpuRLh8POMmrnNMLolWqEauYmu/ajT9eA99hcseahDDhPWgGuSc0mFNS5YcjyIaoKfwWWkvtfqKNBEzf/EnbSsAibQWXUvVCRRLSNdCrImdR+FdprpudQs7sTetP5lU2aP0ChpM8GemidA5ZieNdykW1lVi0Sa6R1gkGzhL03LYzaPzgc8RMJQtaZg93EuSQLs66uKM3+wIDAQABMA0GCSqGSIb3DQEBCwUAA4IBAQBXmX39VyMNsmWn6I5myY9YZbHZEaYJ7xZ4eRbkrNN6znx8ar1YdI5zqpp2J91SL7Ni6IVEqHPPkwh/JI6KcEK5mO4bQxLY5YJb4h0z00jFoyn5IxDkFUgbgWQxRanyeSh0iQDHz0J6hbgjzTft25y87KxrdvJDQ8lxoDuQgSogrw/EAl0hMnauS1m87pjkzhhsYDBRwy0G3muDEgmA1E7RAM00ec/SuDAKvwF7HFf6xgSH8YALstz34drKbkWZIiGQIub3Y4swbN3Myb+whiwCLYW1olubFkvH7anSq6d39ZdJhxXmz3rhK0YlJ9O32WHBA1w/U/4wg8YIv6DSHYGF"],"x5t":"WAcN3AzixLmWqoKdNhhmxilWhFU","x5t#S256":"M4D1NyJsOrtsjG7tRbDs-zd7hg2tvm9kbYDS4gRO7KI"}]}""")

PyJWKSet(certs_from_keycloak["keys"])

Pretty-printed cert for your pleasure

{
  "kid": "A2MJgrKnftrPyUXS-FNN4g0spwz1H89gPTAzjb4u91o",
  "kty": "RSA",
  "alg": "RSA-OAEP",
  "use": "enc",
  "n": "xTT6GOIMi7GXWUNQ4ZoFQuHihNVnRxx9Y9hAcvV6ZO-OiT9dcLqVIlhDckf7yVOfitMG_qZkhIzaOBWNWJZK1_zaeFCv_GQPPEVi_JafLUKz6AAaMdqiFuKfDyoAecOJWc0ar4autehQMpuRLh8POMmrnNMLolWqEauYmu_ajT9eA99hcseahDDhPWgGuSc0mFNS5YcjyIaoKfwWWkvtfqKNBEzf_EnbSsAibQWXUvVCRRLSNdCrImdR-FdprpudQs7sTetP5lU2aP0ChpM8GemidA5ZieNdykW1lVi0Sa6R1gkGzhL03LYzaPzgc8RMJQtaZg93EuSQLs66uKM3-w",
  "e": "AQAB",
  "x5c": [
  "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"
  ],
  "x5t": "WAcN3AzixLmWqoKdNhhmxilWhFU",
  "x5t#S256": "M4D1NyJsOrtsjG7tRbDs-zd7hg2tvm9kbYDS4gRO7KI"
}

System Information

{
  "cryptography": {
    "version": "36.0.1"
  },
  "implementation": {
    "name": "CPython",
    "version": "3.10.1"
  },
  "platform": {
    "release": "5.4.0-91-generic",
    "system": "Linux"
  },
  "pyjwt": {
    "version": "2.3.0"
  }
}

[gchamon]

Seems to be affecting token validation from keycloak 16. Downgrading keycloak to version 15.0.1 solves this issue for me. Waiting for this to be fixed before upgrading keycloak.

[SamuelYaron]

I was running into the same problem. Since keys with algorithms I cannot handle are the same to me as non existing keys, I decided to simply ignore them. I derived a slightly adapted PyJWKClient:

class FilteredPyJWKClient(PyJWKClient):
    """
    A PyJWKClient which ignores keys with unknown algorithms instead of throwing an exception.
    """

    @lru_cache(maxsize=1)
    def _default_algorithms(self):
        return get_default_algorithms()

    def fetch_data(self) -> Any:
        data = super().fetch_data()
        return {"keys": [key for key in data.get("keys", []) if key.get("alg", None) in self._default_algorithms()]}

I am not sure if it could be feasible to integrate this kind of behaviour via a flag during the creation of a genuine PyJWKClient or not, but I just wanted to share the solution that worked for me. As soon as this Issue is resolved I will happily switch to the "official" solution.

[pm-coelho]

As a workaround you can also configure keycloak to disable the RSA-OAEP key or use a different algorithm until it is supported.

Realm->Settings->Keys->rsa-enc-generated->enabled=False

[tiago-peres]

That didn't work for me @pm-coelho while using jboss/keycloak latest version

Notice that alg is now RS256

[pm-coelho]

@tiago-peres do you have the crypto optional dependency dependency installed?

[tiago-peres]

@tiago-peres do you have the crypto optional dependency dependency installed?

Well spotted... I don't and using RUN pip install pyjwt[crypto] doesn't build the image

Then tried RUN pip install cryptography but also

[pm-coelho]

that looks like a missing OS dependency, make sure you have all that crypto requires installed and on $PATH

[tiago-peres]

that looks like a missing OS dependency, make sure you have all that crypto requires installed and on $PATH

you're right again... As per the documentation:

sudo apk add gcc musl-dev python3-dev libffi-dev openssl-dev cargo

it was missing libffi-dev openssl-dev cargo. Currently building the image and will soon test again...

[tiago-peres]

As a workaround you can also configure keycloak to disable the RSA-OAEP key or use a different algorithm until it is supported.

Realm->Settings->Keys->rsa-enc-generated->enabled=False

yep, that's working if we ensure the next steps I've done after! Thank you!

[github-actions]

This issue is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 7 days

[lovasoa]

We encountered the same error while using pyjwt with keycloak. Is support for RSA-OAEP planned ?