Add JWT refresh token model

python/nav/models/api.py

@@ -15,14 +15,18 @@
 #
 """Models for the NAV API"""
 
-from datetime import datetime
+from datetime import datetime, timedelta
+from typing import Dict, Any
+
+import jwt
 
 from django.db import models
 from django.urls import reverse
 
 from nav.adapters import HStoreField
 from nav.models.fields import VarcharField
 from nav.models.profiles import Account
+from nav.jwtconf import JWTConf
 
 
 class APIToken(models.Model):
@@ -66,3 +70,93 @@
 
     class Meta(object):
         db_table = 'apitoken'
+
+
+class JWTRefreshToken(models.Model):
+    """RefreshTokens are used for generating new access tokens"""
+
+    token = VarcharField()
+    name = VarcharField(unique=True)
+    description = models.TextField(null=True, blank=True)
+
+    ACCESS_EXPIRE_DELTA = timedelta(hours=1)
+    REFRESH_EXPIRE_DELTA = timedelta(days=1)
+
+    def __str__(self):
+        return self.token
+
+    def data(self) -> Dict[str, Any]:
+        """Data of token as a dict"""
+        return self.decode_token(self.token)
+
+    def is_active(self) -> bool:
+        """True if token is active. A token is considered active when
+        the nbf claim is in the past and the exp claim is in the future
+        """
+        now = datetime.now()
+        data = self.data()
+        nbf = datetime.fromtimestamp(data['nbf'])
+        exp = datetime.fromtimestamp(data['exp'])
+        return now >= nbf and now < exp
+
+    def expire(self):
+        """Expires the token"""
+        # Base claims for expired token on existing claims
+        expired_data = self.data()
+        expired_data['exp'] = (datetime.now() - timedelta(hours=1)).timestamp()
+        self.token = self.encode_token(expired_data)
+        self.save()
+
+    @classmethod
+    def generate_access_token(cls, token_data: Dict[str, Any] = {}) -> str:
+        """Generates and returns an access token in JWT format.
+        Will use `token_data` as a basis for the new token,
+        but certain claims will be overridden.
+        """
+        return cls._generate_token(token_data, cls.ACCESS_EXPIRE_DELTA, "access_token")
+
+    @classmethod
+    def generate_refresh_token(cls, token_data: Dict[str, Any] = {}) -> str:
+        """Generates and returns a refresh token in JWT format.
+        Will use `token_data` as a basis for the new token,
+        but certain claims will be overridden.
+        """
+        return cls._generate_token(
+            token_data, cls.REFRESH_EXPIRE_DELTA, "refresh_token"
+        )
+
+    @classmethod
+    def _generate_token(
+        cls, token_data: Dict[str, Any], expiry_delta: timedelta, token_type: str
+    ) -> str:
+        """Generates and returns a token in JWT format. Will use `token_data` as a basis
+        for the new token, but certain claims will be overridden
+        """
+        new_token = dict(token_data)
+        now = datetime.now()
+        name = JWTConf().get_nav_name()
+        updated_claims = {
+            'exp': (now + expiry_delta).timestamp(),
+            'nbf': now.timestamp(),
+            'iat': now.timestamp(),
+            'aud': name,
+            'iss': name,
+            'token_type': token_type,
+        }
+        new_token.update(updated_claims)
+        return cls.encode_token(new_token)
+
+    @classmethod
+    def encode_token(cls, token_data: Dict[str, Any]) -> str:
+        """Returns an encoded token in JWT format"""
+        return jwt.encode(
+            token_data, JWTConf().get_nav_private_key(), algorithm="RS256"
+        )
+
+    @classmethod
+    def decode_token(cls, token: str) -> Dict[str, Any]:
+        """Decodes a token in JWT format and returns the data of the decoded token"""
+        return jwt.decode(token, options={'verify_signature': False})
+
+    class Meta(object):
+        db_table = 'jwtrefreshtoken'

python/nav/models/sql/changes/sc.05.05.0002.sql

@@ -0,0 +1,7 @@
+--- Create table for storing JWT refresh tokens
+CREATE TABLE manage.JWTRefreshToken (
+    id SERIAL PRIMARY KEY,
+    token VARCHAR NOT NULL,
+    name VARCHAR NOT NULL UNIQUE,
+    description VARCHAR
+);

requirements/base.txt

@@ -38,3 +38,5 @@ napalm==3.4.1
 
 backports.zoneinfo ; python_version < '3.9'
 git+https://github.com/Uninett/[email protected]#egg=drf-oidc-auth
+
+pyjwt>=2.6.0

tests/unittests/models/jwtrefreshtoken_test.py

@@ -0,0 +1,209 @@
+import pytest
+from unittest.mock import Mock, patch
+from datetime import datetime, timedelta
+from typing import Dict, Any
+
+from nav.models.api import JWTRefreshToken
+
+
+class TestGenerateAccessToken:
+    def test_nbf_should_be_in_the_past(self):
+        encoded_token = JWTRefreshToken.generate_access_token()
+        data = JWTRefreshToken.decode_token(encoded_token)
+        assert data['nbf'] < datetime.now().timestamp()
+
+    def test_exp_should_be_in_the_future(self):
+        encoded_token = JWTRefreshToken.generate_access_token()
+        data = JWTRefreshToken.decode_token(encoded_token)
+        assert data['exp'] > datetime.now().timestamp()
+
+    def test_iat_should_be_in_the_past(self):
+        encoded_token = JWTRefreshToken.generate_access_token()
+        data = JWTRefreshToken.decode_token(encoded_token)
+        assert data['iat'] < datetime.now().timestamp()
+
+    def test_token_type_should_be_access_token(self):
+        encoded_token = JWTRefreshToken.generate_access_token()
+        data = JWTRefreshToken.decode_token(encoded_token)
+        assert data['token_type'] == "access_token"
+
+
+class TestGenerateRefreshToken:
+    def test_nbf_should_be_in_the_past(self):
+        encoded_token = JWTRefreshToken.generate_refresh_token()
+        data = JWTRefreshToken.decode_token(encoded_token)
+        assert data['nbf'] < datetime.now().timestamp()
+
+    def test_exp_should_be_in_the_future(self):
+        encoded_token = JWTRefreshToken.generate_refresh_token()
+        data = JWTRefreshToken.decode_token(encoded_token)
+        assert data['exp'] > datetime.now().timestamp()
+
+    def test_iat_should_be_in_the_past(self):
+        encoded_token = JWTRefreshToken.generate_refresh_token()
+        data = JWTRefreshToken.decode_token(encoded_token)
+        assert data['iat'] < datetime.now().timestamp()
+
+    def test_token_type_should_be_refresh_token(self):
+        encoded_token = JWTRefreshToken.generate_refresh_token()
+        data = JWTRefreshToken.decode_token(encoded_token)
+        assert data['token_type'] == "refresh_token"
+
+
+class TestIsActive:
+    def test_should_return_false_if_nbf_is_in_the_future(self, refresh_token_data):
+        refresh_token_data['nbf'] = (datetime.now() + timedelta(hours=1)).timestamp()
+        refresh_token_data['exp'] = (datetime.now() + timedelta(hours=1)).timestamp()
+        encoded_token = JWTRefreshToken.encode_token(refresh_token_data)
+        token = JWTRefreshToken(token=encoded_token)
+        assert not token.is_active()
+
+    def test_should_return_false_if_exp_is_in_the_past(self, refresh_token_data):
+        refresh_token_data['nbf'] = (datetime.now() - timedelta(hours=1)).timestamp()
+        refresh_token_data['exp'] = (datetime.now() - timedelta(hours=1)).timestamp()
+        encoded_token = JWTRefreshToken.encode_token(refresh_token_data)
+        token = JWTRefreshToken(token=encoded_token)
+        assert not token.is_active()
+
+    def test_should_return_true_if_nbf_is_in_the_past_and_exp_is_in_the_future(
+        self, refresh_token_data
+    ):
+        now = datetime.now()
+        refresh_token_data['nbf'] = (now - timedelta(hours=1)).timestamp()
+        refresh_token_data['exp'] = (now + timedelta(hours=1)).timestamp()
+        encoded_token = JWTRefreshToken.encode_token(refresh_token_data)
+        token = JWTRefreshToken(token=encoded_token)
+        assert token.is_active()
+
+
+class TestExpire:
+    def test_should_make_active_token_inactive(self, refresh_token_data):
+        now = datetime.now()
+        # set claims so the token starts as being active
+        refresh_token_data['nbf'] = now - timedelta(hours=1)
+        refresh_token_data['exp'] = now + timedelta(hours=1)
+        encoded_token = JWTRefreshToken.encode_token(refresh_token_data)
+        token = JWTRefreshToken(token=encoded_token)
+        token.save = Mock()
+        assert token.is_active()
+        token.expire()
+        assert not token.is_active()
+
+
+class TestData:
+    def test_should_return_accurate_representation_of_token_data(
+        self, refresh_token, refresh_token_data
+    ):
+        token = JWTRefreshToken(token=refresh_token)
+        assert token.data() == refresh_token_data
+
+
+class TestDecodeToken:
+    def test_should_return_same_data_as_token_was_encoded_with(
+        self, refresh_token, refresh_token_data
+    ):
+        decoded_data = JWTRefreshToken.decode_token(refresh_token)
+        assert decoded_data == refresh_token_data
+
+
+class TestEncodeToken:
+    def test_should_generate_same_string_as_a_known_token_that_was_made_with_same_input(
+        self, refresh_token, refresh_token_data
+    ):
+        encoded_token = JWTRefreshToken.encode_token(refresh_token_data)
+        assert encoded_token == refresh_token
+
+
+@pytest.fixture()
+def refresh_token_data() -> Dict[Any, str]:
+    """Yields the data of the token in the refresh_token fixture"""
+    data = {
+        "exp": 1516339022,
+        "nbf": 1516239022,
+        "iat": 1516239022,
+        "aud": "nav",
+        "iss": "nav",
+        "token_type": "refresh_token",
+    }
+    yield data
+
+
+@pytest.fixture()
+def refresh_token() -> str:
+    """Yields a refresh token with data matching the refresh_token_data fixture"""
+    token = "eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE1\
+MTYzMzkwMjIsIm5iZiI6MTUxNjIzOTAyMiwiaWF0IjoxNTE2MjM5MDIyLCJh\
+dWQiOiJuYXYiLCJpc3MiOiJuYXYiLCJ0b2tlbl90eXBlIjoicmVmcmVzaF90\
+b2tlbiJ9.LC5YhPTrOQk2q-gPgPHAf9nWF8zjBFBmM6AEh1gSjJgvBdrwqsZ\
+7lqsEAQ09IXBrsZ3UhJDkEh5e31Tcp9afk_5f2dLA5zwcayxEbJ7Bj3M0PPb\
+D_jz5YWqJ1x9YwROh_iOVtTtVze8079rpF_0LIgbibJjJ1BLrvHLtYhTACTx\
+PKfmSJXK60_bg1jRPtlFIilNVdYQ3mnOXjg-9AjsCDH4nzABwiIpAXBR1r-9\
+3AZ_ZYxygwctVQpbIJIr0lTntczZ5sRudpK271JHdvLe-iZFz6MpfNIRBJS8\
+qawbo_kZmetm6zWmrPDcyC95tYfd2JL8XhEGGpB3nfhQipqG8nQ"
+    yield token
+
+
+@pytest.fixture(scope="module", autouse=True)
+def jwtconf_mock(private_key, nav_name) -> str:
+    """Mocks the get_nave_name and get_nav_private_key functions for
+    the JWTConf class
+    """
+    with patch("nav.models.api.JWTConf") as _jwtconf_mock:
+        instance = _jwtconf_mock.return_value
+        instance.get_nav_name = Mock(return_value=nav_name)
+        instance.get_nav_private_key = Mock(return_value=private_key)
+        yield _jwtconf_mock
+
+
+@pytest.fixture(scope="module")
+def private_key() -> str:
+    """Yields a private key in PEM format"""
+    key = """-----BEGIN PRIVATE KEY-----
+MIIEuwIBADANBgkqhkiG9w0BAQEFAASCBKUwggShAgEAAoIBAQCp+4AEZM4uYZKu
+/hrKzySMTFFx3/ncWo6XAFpADQHXLOwRB9Xh1/OwigHiqs/wHRAAmnrlkwCCQA8r
+xiHBAMjp5ApbkyggQz/DVijrpSba6Tiy1cyBTZC3cvOK2FpJzsakJLhIXD1HaULO
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+3oLU1TmvAgMBAAECgf8zrhi95+gdMeKRpwV+TnxOK5CXjqvo0vTcnr7Runf/c9On
+WeUtRPr83E4LxuMcSGRqdTfoP0loUGb3EsYwZ+IDOnyWWvytfRoQdExSA2RM1PDo
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+e2JsSubS+9RI2ktMlSKaemr8yeoIpsXfAiJSHkECgYEA0NKU18xK+9w5IXfgNwI4
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+ZCaDbJbVxQ2f8s/GajKwEz/BDwqievnVH0zJxmr/kyyqw5Ybh5HVvA1GfqaVRssJ
+DvTjZQDft0a9Lyy7ix1OS2XgkcMjTWj840LNPwKBgDPXMBgL5h41jd7jCsXzPhyr
+V96RzQkPcKsoVvrCoNi8eoEYgRd9jwfiU12rlXv+fgVXrrfMoJBoYT6YtrxEJVdM
+RAjRpnE8PMqCUA8Rd7RFK9Vp5Uo8RxTNvk9yPvDv1+lHHV7lEltIk5PXuKPHIrc1
+nNUyhzvJs2Qba2L/huNC
+-----END PRIVATE KEY-----"""
+    yield key
+
+
+@pytest.fixture()
+def public_key() -> str:
+    """Yields a public key in PEM format"""
+    key = """-----BEGIN PUBLIC KEY-----
+MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAqfuABGTOLmGSrv4ays8k
+jExRcd/53FqOlwBaQA0B1yzsEQfV4dfzsIoB4qrP8B0QAJp65ZMAgkAPK8YhwQDI
+6eQKW5MoIEM/w1Yo66Um2uk4stXMgU2Qt3LzithaSc7GpCS4SFw9R2lCzgpciCQf
+2K5h5kHPEi91M6LuZjKXXAQtqc8JhFtXL0FEaZ74KwxfFfOhq0JIyupyDyBHrlup
+Gw+ZVhQD3y39aIQ1nsd8sXkhclzUQKSYWxeB6yhXpj5Dou2nLJMt/FKJkI2YADBz
+6LSTZELwB3J1x4YNBXFhnaIb+W3PwrbfRsGTsyccMiSwQbEnsGxN9dE2Yt6C1NU5
+rwIDAQAB
+-----END PUBLIC KEY-----"""
+    yield key
+
+
+@pytest.fixture(scope="module")
+def nav_name() -> str:
+    yield "nav"