Using the MSAL With Split Context

Question

Hello,

I am developing a plugin for an Android application that uses the Microsoft Authentication Library to login with the user's Microsoft account. The tricky part about plugin development is I have to juggle two forms of android.content.Context: the context of the main application and the context of the plugin. The split context seems to be preventing me from creating an instance of PublicClientApplication. The configuration files (both my custom config and the default config included in the library) live within the context of the plugin, but PublicClientApplication requires the application context. If I use the application context, the MSAL throws an exception when it tries to load the default configuration (I use the plugin context to load my config into a File object and pass this in instead of the resource ID). If I use the plugin context, the MSAL throws an exception when it tries to validate the context. How can I use the MSAL in this scenario? Looking at PublicClientApplicationConfigurationFactory, there did not seem to be any way around loading msal_default_config.json?

Answer 1

Hi Allen,

Thank you for posting your query on Microsoft Q&A.

When using MSAL in an Android plugin, the main issue usually comes from how the library handles context. MSAL needs the application’s context, not the plugin’s context, to load its configuration and work correctly. If MSAL is initialized with the wrong context, it cannot find the configuration file (msal_default_config.json), and authentication will fail.

• Your plugin runs with its own context, which does not have access to the app’s resources.
• MSAL requires the actual application context so it can read the MSAL configuration file and initialize properly.

Please follow the instructions below to fix the issue:

1. Initialize MSAL using the main application context

• Always pass the app’s context, not the plugin’s context, when creating the PublicClientApplication instance.
• If your plugin can’t access the app context directly, expose a method in the host app that returns it, and call that from your plugin.

2. If using a custom config file, load it manually

• If the plugin needs to load its own MSAL config:
• Open the JSON file as an InputStream
• Pass that stream to MSAL using the constructor that accepts configuration from a stream
• This ensures MSAL uses the correct config even though it’s running inside a plugin.

3. Manage contexts carefully

• If your plugin switches between its own context and the app context, create a small helper class to:
• Store the application context
• Ensure MSAL always receives the correct one
• This avoids inconsistent behavior during authentication.

4. Check MSAL error messages

• If MSAL still fails:
• Look for errors about missing config files or invalid context
• These messages usually point directly to whether the problem is resource access or configuration.

Microsoft documentation:

• Microsoft Authentication Library (MSAL) for Android
• Developing apps with Microsoft Entra ID

I hope this information is helpful. Please feel free to reach out if you have any further questions. If the answer is helpful, please click "Accept Answer" and kindly upvote it.