def test_evicts_invalid_refresh_token():
"""when AAD rejects a refresh token, the client should evict that token from its cache"""
tenant_id = "tenant-id"
client_id = "client-id"
invalid_token = "invalid-refresh-token"
cache = TokenCache()
cache.add({"response": build_aad_response(uid="id1", utid="tid1", access_token="*", refresh_token=invalid_token)})
cache.add({"response": build_aad_response(uid="id2", utid="tid2", access_token="*", refresh_token="...")})
assert len(cache.find(TokenCache.CredentialType.REFRESH_TOKEN)) == 2
assert len(cache.find(TokenCache.CredentialType.REFRESH_TOKEN, query={"secret": invalid_token})) == 1
def send(request, **_):
assert request.data["refresh_token"] == invalid_token
return mock_response(json_payload={"error": "invalid_grant"}, status_code=400)
transport = Mock(send=Mock(wraps=send))
client = AadClient(tenant_id, client_id, transport=transport, cache=cache)
with pytest.raises(ClientAuthenticationError):
client.obtain_token_by_refresh_token(scopes=("scope",), refresh_token=invalid_token)
assert transport.send.call_count == 1
assert len(cache.find(TokenCache.CredentialType.REFRESH_TOKEN)) == 1
assert len(cache.find(TokenCache.CredentialType.REFRESH_TOKEN, query={"secret": invalid_token})) == 0
class AuthnClientBase(object):
"""Sans I/O authentication client methods"""
def __init__(self, auth_url, **kwargs):
# type: (str, Mapping[str, Any]) -> None
if not auth_url:
raise ValueError("auth_url should be the URL of an OAuth endpoint")
super(AuthnClientBase, self).__init__()
self._auth_url = auth_url
self._cache = TokenCache()
def get_cached_token(self, scopes):
# type: (Iterable[str]) -> Optional[str]
tokens = self._cache.find(TokenCache.CredentialType.ACCESS_TOKEN,
list(scopes))
for token in tokens:
if all((scope in token["target"] for scope in scopes)):
if int(token["expires_on"]) - 300 > int(time()):
return token["secret"]
return None
def _deserialize_and_cache_token(self, response, scopes):
# type: (PipelineResponse, Iterable[str]) -> str
try:
if "deserialized_data" in response.context:
payload = response.context["deserialized_data"]
else:
payload = response.http_response.text()
token = payload["access_token"]
# these values are strings in IMDS responses but msal.TokenCache requires they be integers
# https://github.com/AzureAD/microsoft-authentication-library-for-python/pull/55
if payload.get("expires_in"):
payload["expires_in"] = int(payload["expires_in"])
if payload.get("ext_expires_in"):
payload["ext_expires_in"] = int(payload["ext_expires_in"])
self._cache.add({"response": payload, "scope": scopes})
return token
except KeyError:
raise AuthenticationError(
"Unexpected authentication response: {}".format(payload))
except Exception as ex:
raise AuthenticationError("Authentication failed: {}".format(
str(ex)))
def _prepare_request(self,
method="POST",
headers=None,
form_data=None,
params=None):
# type: (Optional[str], Optional[Mapping[str, str]], Optional[Mapping[str, str]], Optional[Dict[str, str]]) -> HttpRequest
request = HttpRequest(method, self._auth_url, headers=headers)
if form_data:
request.headers[
"Content-Type"] = "application/x-www-form-urlencoded"
request.set_formdata_body(form_data)
if params:
request.format_parameters(params)
return request
def test_persistent_cache_multiple_clients(cert_path, cert_password):
"""the credential shouldn't use tokens issued to other service principals"""
access_token_a = "token a"
access_token_b = "not " + access_token_a
transport_a = msal_validating_transport(
requests=[Request()],
responses=[
mock_response(json_payload=build_aad_response(
access_token=access_token_a))
])
transport_b = msal_validating_transport(
requests=[Request()],
responses=[
mock_response(json_payload=build_aad_response(
access_token=access_token_b))
])
cache = TokenCache()
with patch(
"azure.identity._internal.msal_credentials._load_persistent_cache"
) as mock_cache_loader:
mock_cache_loader.return_value = Mock(wraps=cache)
credential_a = CertificateCredential(
"tenant",
"client-a",
cert_path,
password=cert_password,
transport=transport_a,
cache_persistence_options=TokenCachePersistenceOptions(),
)
assert mock_cache_loader.call_count == 1, "credential should load the persistent cache"
credential_b = CertificateCredential(
"tenant",
"client-b",
cert_path,
password=cert_password,
transport=transport_b,
cache_persistence_options=TokenCachePersistenceOptions(),
)
assert mock_cache_loader.call_count == 2, "credential should load the persistent cache"
# A caches a token
scope = "scope"
token_a = credential_a.get_token(scope)
assert token_a.token == access_token_a
assert transport_a.send.call_count == 3 # two MSAL discovery requests, one token request
# B should get a different token for the same scope
token_b = credential_b.get_token(scope)
assert token_b.token == access_token_b
assert transport_b.send.call_count == 3
assert len(cache.find(TokenCache.CredentialType.ACCESS_TOKEN)) == 2
def test_writes_to_cache():
"""the credential should write tokens it acquires to the cache"""
scope = "scope"
expected_access_token = "access token"
first_refresh_token = "first refresh token"
second_refresh_token = "second refresh token"
username = "******"
uid = "uid"
utid = "utid"
account = get_account_event(username=username, uid=uid, utid=utid, refresh_token=first_refresh_token)
cache = TokenCache()
cache.add(account)
transport = validating_transport(
requests=[Request(required_data={"refresh_token": first_refresh_token})], # credential redeems refresh token
responses=[
mock_response(
json_payload=build_aad_response( # AAD responds with an access token and new refresh token
uid=uid,
utid=utid,
access_token=expected_access_token,
refresh_token=second_refresh_token,
id_token=build_id_token(
aud=DEVELOPER_SIGN_ON_CLIENT_ID, object_id=uid, tenant_id=utid, username=username
),
)
)
],
)
credential = SharedTokenCacheCredential(_cache=cache, transport=transport)
token = credential.get_token(scope)
assert token.token == expected_access_token
# access token should be in the cache, and another instance should retrieve it
credential = SharedTokenCacheCredential(
_cache=cache, transport=Mock(send=Mock(side_effect=Exception("the credential should return a cached token")))
)
token = credential.get_token(scope)
assert token.token == expected_access_token
# and the credential should have updated the cached refresh token
second_access_token = "second access token"
transport = validating_transport(
requests=[Request(required_data={"refresh_token": second_refresh_token})],
responses=[mock_response(json_payload=build_aad_response(access_token=second_access_token))],
)
credential = SharedTokenCacheCredential(_cache=cache, transport=transport)
token = credential.get_token("some other " + scope)
assert token.token == second_access_token
# verify the credential didn't add a new cache entry
assert len(cache.find(TokenCache.CredentialType.REFRESH_TOKEN)) == 1
async def test_cache_multiple_clients():
"""the credential shouldn't use tokens issued to other service principals"""
access_token_a = "token a"
access_token_b = "not " + access_token_a
transport_a = async_validating_transport(
requests=[Request()],
responses=[
mock_response(json_payload=build_aad_response(
access_token=access_token_a))
])
transport_b = async_validating_transport(
requests=[Request()],
responses=[
mock_response(json_payload=build_aad_response(
access_token=access_token_b))
])
cache = TokenCache()
with patch(ClientSecretCredential.__module__ +
"._load_persistent_cache") as mock_cache_loader:
mock_cache_loader.return_value = Mock(wraps=cache)
credential_a = ClientSecretCredential(
"tenant",
"client-a",
"secret",
transport=transport_a,
cache_persistence_options=TokenCachePersistenceOptions(),
)
assert mock_cache_loader.call_count == 1, "credential should load the persistent cache"
credential_b = ClientSecretCredential(
"tenant",
"client-b",
"secret",
transport=transport_b,
cache_persistence_options=TokenCachePersistenceOptions(),
)
assert mock_cache_loader.call_count == 2, "credential should load the persistent cache"
# A caches a token
scope = "scope"
token_a = await credential_a.get_token(scope)
assert token_a.token == access_token_a
assert transport_a.send.call_count == 1
# B should get a different token for the same scope
token_b = await credential_b.get_token(scope)
assert token_b.token == access_token_b
assert transport_b.send.call_count == 1
assert len(cache.find(TokenCache.CredentialType.ACCESS_TOKEN)) == 2
class AuthnClientBase(object):
"""Sans I/O authentication client methods"""
def __init__(self, auth_url, **kwargs):
# type: (str, Mapping[str, Any]) -> None
if not auth_url:
raise ValueError("auth_url should be the URL of an OAuth endpoint")
super(AuthnClientBase, self).__init__()
self._auth_url = auth_url
self._cache = TokenCache()
def get_cached_token(self, scopes):
# type: (Iterable[str]) -> Optional[AccessToken]
tokens = self._cache.find(TokenCache.CredentialType.ACCESS_TOKEN,
list(scopes))
for token in tokens:
if all((scope in token["target"] for scope in scopes)):
expires_on = int(token["expires_on"])
if expires_on - 300 > int(time.time()):
return AccessToken(token["secret"], expires_on)
return None
def _deserialize_and_cache_token(self, response, scopes, request_time):
# type: (PipelineResponse, Iterable[str], int) -> AccessToken
# ContentDecodePolicy sets this, and should have raised if it couldn't deserialize the response
payload = response.context[ContentDecodePolicy.CONTEXT_NAME]
if not payload or "access_token" not in payload or not (
"expires_in" in payload or "expires_on" in payload):
if payload and "access_token" in payload:
payload["access_token"] = "****"
raise ClientAuthenticationError(
message="Unexpected response '{}'".format(payload))
token = payload["access_token"]
# AccessToken wants expires_on as an int
expires_on = payload.get("expires_on") or int(
payload["expires_in"]) + request_time
try:
expires_on = int(expires_on)
except ValueError:
# probably an App Service MSI response, convert it to epoch seconds
try:
t = self._parse_app_service_expires_on(expires_on)
expires_on = calendar.timegm(t)
except ValueError:
# have a token but don't know when it expires -> treat it as single-use
expires_on = request_time
# now we have an int expires_on, ensure the cache entry gets it
payload["expires_on"] = expires_on
self._cache.add({"response": payload, "scope": scopes})
return AccessToken(token, expires_on)
@staticmethod
def _parse_app_service_expires_on(expires_on):
# type: (str) -> struct_time
"""
Parse expires_on from an App Service MSI response (e.g. "06/19/2019 23:42:01 +00:00") to struct_time.
Expects the time is given in UTC (i.e. has offset +00:00).
"""
if not expires_on.endswith(" +00:00"):
raise ValueError(
"'{}' doesn't match expected format".format(expires_on))
# parse the string minus the timezone offset
return time.strptime(expires_on[:-len(" +00:00")], "%m/%d/%Y %H:%M:%S")
# TODO: public, factor out of request_token
def _prepare_request(self,
method="POST",
headers=None,
form_data=None,
params=None):
# type: (Optional[str], Optional[Mapping[str, str]], Optional[Mapping[str, str]], Optional[Dict[str, str]]) -> HttpRequest
request = HttpRequest(method, self._auth_url, headers=headers)
if form_data:
request.headers[
"Content-Type"] = "application/x-www-form-urlencoded"
request.set_formdata_body(form_data)
if params:
request.format_parameters(params)
return request
class AadClientBase(ABC):
"""Sans I/O methods for AAD clients wrapping MSAL's OAuth client"""
def __init__(self, tenant_id, client_id, **kwargs):
# type: (str, str, **Any) -> None
authority = kwargs.pop("authority",
KnownAuthorities.AZURE_PUBLIC_CLOUD)
if authority[-1] == "/":
authority = authority[:-1]
token_endpoint = "https://" + "/".join(
(authority, tenant_id, "oauth2/v2.0/token"))
config = {"token_endpoint": token_endpoint}
self._client = Client(server_configuration=config, client_id=client_id)
self._client.session.close()
self._client.session = self._get_client_session(**kwargs)
self._cache = TokenCache()
def get_cached_access_token(self, scopes):
# type: (Iterable[str]) -> Optional[AccessToken]
tokens = self._cache.find(TokenCache.CredentialType.ACCESS_TOKEN,
target=list(scopes))
for token in tokens:
expires_on = int(token["expires_on"])
if expires_on - 300 > int(time.time()):
return AccessToken(token["secret"], expires_on)
return None
def get_cached_refresh_tokens(self, scopes):
"""Assumes all cached refresh tokens belong to the same user"""
return self._cache.find(TokenCache.CredentialType.REFRESH_TOKEN,
target=list(scopes))
def obtain_token_by_authorization_code(self, code, redirect_uri, scopes,
**kwargs):
# type: (str, str, Iterable[str], **Any) -> AccessToken
fn = functools.partial(self._client.obtain_token_by_authorization_code,
code=code,
redirect_uri=redirect_uri,
**kwargs)
return self._obtain_token(scopes, fn, **kwargs)
def obtain_token_by_refresh_token(self, refresh_token, scopes, **kwargs):
# type: (str, Iterable[str], **Any) -> AccessToken
fn = functools.partial(self._client.obtain_token_by_refresh_token,
token_item=refresh_token,
scope=scopes,
rt_getter=lambda token: token["secret"],
**kwargs)
return self._obtain_token(scopes, fn, **kwargs)
def _process_response(self, response, scopes, now):
# type: (dict, Iterable[str], int) -> AccessToken
_raise_for_error(response)
self._cache.add(event={"response": response, "scope": scopes}, now=now)
if "expires_on" in response:
expires_on = int(response["expires_on"])
elif "expires_in" in response:
expires_on = now + int(response["expires_in"])
else:
_scrub_secrets(response)
raise ClientAuthenticationError(
message="Unexpected response from Azure Active Directory: {}".
format(response))
return AccessToken(response["access_token"], expires_on)
@abc.abstractmethod
def _get_client_session(self, **kwargs):
pass
@abc.abstractmethod
def _obtain_token(self, scopes, fn, **kwargs):
# type: (Iterable[str], Callable, **Any) -> AccessToken
pass
class AuthnClientBase(object):
"""Sans I/O authentication client methods"""
def __init__(self, auth_url, **kwargs):
# type: (str, Mapping[str, Any]) -> None
if not auth_url:
raise ValueError("auth_url should be the URL of an OAuth endpoint")
super(AuthnClientBase, self).__init__()
self._auth_url = auth_url
self._cache = TokenCache()
def get_cached_token(self, scopes):
# type: (Iterable[str]) -> Optional[AccessToken]
tokens = self._cache.find(TokenCache.CredentialType.ACCESS_TOKEN,
list(scopes))
for token in tokens:
if all((scope in token["target"] for scope in scopes)):
expires_on = int(token["expires_on"])
if expires_on - 300 > int(time.time()):
return AccessToken(token["secret"], expires_on)
return None
def _deserialize_and_cache_token(self, response, scopes, request_time):
# type: (PipelineResponse, Iterable[str], int) -> str
try:
if "deserialized_data" in response.context:
payload = response.context["deserialized_data"]
else:
payload = response.http_response.text()
token = payload["access_token"]
# these values are strings in IMDS responses but msal.TokenCache requires they be integers
# https://github.com/AzureAD/microsoft-authentication-library-for-python/pull/55
expires_in = int(payload.get("expires_in", 0))
if expires_in != 0:
payload["expires_in"] = expires_in
if "ext_expires_in" in payload:
payload["ext_expires_in"] = int(payload["ext_expires_in"])
self._cache.add({"response": payload, "scope": scopes})
# AccessToken contains the token's expires_on time. There are four cases for setting it:
# 1. response has expires_on -> AccessToken uses it
# 2. response has expires_on and expires_in -> AccessToken uses expires_on
# 3. response has only expires_in -> AccessToken uses expires_in + time of request
# 4. response has neither expires_on or expires_in -> AccessToken sets expires_on = 0
# (not expecting this case; if it occurs, the token is effectively single-use)
expires_on = payload.get("expires_on", 0)
return AccessToken(token, expires_on or expires_in + request_time)
except KeyError:
if "access_token" in payload:
payload["access_token"] = "****"
raise AuthenticationError(
"Unexpected authentication response: {}".format(payload))
except Exception as ex:
raise AuthenticationError("Authentication failed: {}".format(
str(ex)))
# TODO: public, factor out of request_token
def _prepare_request(self,
method="POST",
headers=None,
form_data=None,
params=None):
# type: (Optional[str], Optional[Mapping[str, str]], Optional[Mapping[str, str]], Optional[Dict[str, str]]) -> HttpRequest
request = HttpRequest(method, self._auth_url, headers=headers)
if form_data:
request.headers[
"Content-Type"] = "application/x-www-form-urlencoded"
request.set_formdata_body(form_data)
if params:
request.format_parameters(params)
return request