import_refresh_token() for RT migration

msal/application.py

@@ -700,6 +700,28 @@ def _validate_ssh_cert_input_data(self, data):
                     "you must include a string parameter named 'key_id' "
                     "which identifies the key in the 'req_cnf' argument.")
 
+    def import_refresh_token(self, refresh_token, scopes):
+        """Import an RT from elsewhere into MSAL's token cache.
+
+        :param str refresh_token: The old refresh token, as a string.
+
+        :param list scopes:
+            The scopes associate with this old RT.
+            Each scope needs to be in the Microsoft identity platform (v2) format.
+            https://docs.microsoft.com/en-us/azure/active-directory/develop/migrate-python-adal-msal#scopes-not-resources
+
+        :return:
+            * A dict contains "error" and some other keys, when error happened.
+            * A dict contains no "error" key.
+        """
+        result = self.client.obtain_token_by_refresh_token(
+            refresh_token,
+            decorate_scope(scopes, self.client_id),
+            rt_getter=lambda rt: rt,
+            on_updating_rt=False,
+            )
+        return {} if "error" not in result else result  # Returns NO token
+
 
 class PublicClientApplication(ClientApplication):  # browser app or mobile app
 

sample/migrate_rt.py

@@ -0,0 +1,75 @@
+"""
+The configuration file would look like this:
+
+{
+    "authority": "https://login.microsoftonline.com/organizations",
+    "client_id": "your_client_id",
+    "scope": ["User.ReadBasic.All"],
+        // You can find the other permission names from this document
+        // https://docs.microsoft.com/en-us/graph/permissions-reference
+}
+
+You can then run this sample with a JSON configuration file:
+
+    python sample.py parameters.json
+"""
+
+import sys  # For simplicity, we'll read config file from 1st CLI param sys.argv[1]
+import json
+import logging
+
+import msal
+
+
+# Optional logging
+# logging.basicConfig(level=logging.DEBUG)  # Enable DEBUG log for entire script
+# logging.getLogger("msal").setLevel(logging.INFO)  # Optionally disable MSAL DEBUG logs
+
+config = json.load(open(sys.argv[1]))
+
+def get_rt_via_old_app():
+    # Let's pretend this is an old app powered by ADAL
+    app = msal.PublicClientApplication(
+        config["client_id"], authority=config["authority"])
+    flow = app.initiate_device_flow(scopes=config["scope"])
+    if "user_code" not in flow:
+        raise ValueError(
+            "Fail to create device flow. Err: %s" % json.dumps(flow, indent=4))
+    print(flow["message"])
+    sys.stdout.flush()  # Some terminal needs this to ensure the message is shown
+
+    # Ideally you should wait here, in order to save some unnecessary polling
+    # input("Press Enter after signing in from another device to proceed, CTRL+C to abort.")
+
+    result = app.acquire_token_by_device_flow(flow)  # By default it will block
+    assert "refresh_token" in result, "We should have a successful result"
+    return result["refresh_token"]
+
+try:  # For easier testing, we try to reload a RT from previous run
+    old_rt = json.load(open("rt.json"))[0]
+except:  # If that is not possible, we acquire a RT
+    old_rt = get_rt_via_old_app()
+    json.dump([old_rt], open("rt.json", "w"))
+
+# Now we will try to migrate this old_rt into a new app powered by MSAL
+
+token_cache = msal.SerializableTokenCache()
+assert token_cache.serialize() == '{}', "Token cache is initially empty"
+app = msal.PublicClientApplication(
+    config["client_id"], authority=config["authority"], token_cache=token_cache)
+result = app.import_refresh_token(old_rt, config["scope"])
+if "error" in result:
+    print("Migration unsuccessful. Error: ", json.dumps(result, indent=2))
+else:
+    print("Migration is successful")
+    logging.debug("Token cache contains: %s", token_cache.serialize())
+
+# From now on, the RT is saved inside MSAL's cache,
+# and becomes available in normal MSAL coding pattern. For example:
+accounts = app.get_accounts()
+if accounts:
+    account = accounts[0]  # Assuming end user pick this account
+    result = app.acquire_token_silent(config["scope"], account)
+    if "access_token" in result:
+        print("RT is available in MSAL's cache, and can be used to acquire new AT")
+