What is the recommended authentication solution for a mobile application connecting to Salesforce?

The recommended authentication solution for a mobile application connecting to Salesforce is to redirect the user to Salesforce via the User-agent OAuth flow to obtain an access token and refresh token. This method is aligned with best practices for security and user experience.

Using the User-agent OAuth flow allows for a secure and standard way to authenticate users without exposing sensitive credentials within the mobile application's code. This approach enables the mobile app to leverage Salesforce's OAuth 2.0 framework, which provides robust security mechanisms, such as using short-lived access tokens that can be refreshed without requiring the user to input their credentials again.

Additionally, this method minimizes risks associated with hardcoding credentials or managing sensitive information within the app. By redirecting users to authenticate through the Salesforce login page, it allows Salesforce to handle the authentication process securely, preventing potential breaches of user credentials.

In contrast, approaches that involve storing integration user credentials within the app or prompting users directly for credentials may expose the application to security vulnerabilities, such as credential theft or leakage in case the application is decompiled or accessed by unauthorized users. Therefore, utilizing the OAuth User-agent flow not only enhances security but also improves user experience by simplifying the login process and supporting single sign-on capabilities.