How do you create and enforce a content security policy across multiple platforms and devices?

1 Define your content sources

The first step is to identify and categorize the content sources that you use or depend on, such as scripts, stylesheets, images, fonts, media, or third-party services. You can use tools like Content Security Policy Generator or CSP Evaluator to generate a basic policy based on your website or app. However, you should also review and customize your policy according to your specific needs and goals.

2 Test and refine your policy

Before you implement your policy, you should test it in a development or staging environment to check for any errors, warnings, or unintended effects. You can use tools like the Content Security Policy Report-Only Header or the Content-Security-Policy-Report-Only meta tag to enable reporting mode, which allows you to monitor and collect feedback on your policy without enforcing it. You can also use browser developer tools or extensions to debug and troubleshoot your policy.

3 Implement and enforce your policy

Once you are satisfied with your policy, you can implement and enforce it by using either the Content Security Policy Header or the Content-Security-Policy meta tag. You should choose the method that best suits your platform and device, as well as your deployment and maintenance process. For example, if you use a content management system (CMS) or a web framework, you may be able to configure your policy through the settings or plugins. If you use a static website or a single-page app, you may need to add the meta tag manually or through a build tool.

4 Monitor and update your policy

Creating and enforcing a CSP is not a one-time task, but an ongoing process. You should regularly monitor and update your policy to reflect any changes in your content sources, platform features, or security requirements. You can use tools like the Content Security Policy Violation Report Endpoint or the Content-Security-Policy-Report-Only meta tag to collect and analyze reports on your policy violations or warnings. You can also use tools like the Content Security Policy Scanner or the CSP Tester to audit and validate your policy.

5 Adapt your policy to different platforms and devices

A CSP is not a one-size-fits-all solution, but a flexible and adaptable one. You may need to adjust your policy to different platforms and devices, depending on their capabilities, limitations, or preferences. For example, you may need to use different directives, values, or fallbacks for desktop, mobile, or IoT devices. You may also need to use different policies for different browsers, versions, or user agents. You can use tools like the Content Security Policy Browser Test or the Content-Security-Policy meta tag with the media attribute to test and apply your policy to different scenarios.

6 Learn from best practices and resources

Creating and enforcing a CSP across multiple platforms and devices can be challenging, but rewarding. It can help you improve your security, performance, and user experience. However, it can also require some trial and error, research, and learning. You can benefit from following best practices and resources from experts, communities, and organizations. For example, you can check out the Content Security Policy Level 3 specification, the Mozilla Developer Network documentation, or the Google Web Fundamentals guide for more information and guidance.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?