Refused to load the font ‘data:font/woff…..’it violates the following Content Security Policy directive: “default-src ‘self’”. Note that ‘font-src’

Refused to load the font ‘data:font/woff…..’it violates the following Content Security Policy directive: “default-src ‘self’”. Note that ‘font-src’

If you have encountered the error message “Refused to load the font ‘data:font/woff…..’it violates the following Content Security Policy directive: ‘default-src ‘self”. Note that ‘font-src’”, you are not alone. This error is related to the Content Security Policy (CSP) directive and can occur when trying to load fonts in your JavaScript application.

The Content Security Policy is a security mechanism that helps prevent cross-site scripting (XSS) attacks by defining the sources from which certain types of content can be loaded. The ‘default-src’ directive specifies the default source for all types of content, including fonts.

When the error message mentions ‘font-src’, it means that the font you are trying to load violates the ‘font-src’ directive specified in the Content Security Policy. This directive controls the sources from which fonts can be loaded.

There are a few solutions to this problem:

Solution 1: Modify the Content Security Policy directive

The first solution is to modify the ‘font-src’ directive in the Content Security Policy to allow the font to be loaded. You can add the source of the font to the ‘font-src’ directive.

Here’s an example of how you can modify the ‘font-src’ directive:

Content-Security-Policy: default-src 'self'; font-src 'self' data:;

In the above example, we have added the ‘data:’ source to the ‘font-src’ directive, allowing fonts to be loaded from the ‘data:’ scheme.

Solution 2: Use a separate CSS file for fonts

Another solution is to separate the CSS file that contains the font declarations from the JavaScript file. By doing this, you can specify a different Content Security Policy for the CSS file, allowing fonts to be loaded from additional sources.

Here’s an example of how you can specify a separate Content Security Policy for the CSS file:

In the above example, we have added the ‘data:’ source to the ‘font-src’ directive in the Content Security Policy specified in the ‘link’ tag. This allows fonts to be loaded from the ‘data:’ scheme.

Solution 3: Base64 encode the font

If modifying the Content Security Policy is not an option, you can try base64 encoding the font and embedding it directly in your CSS file. This way, the font is treated as a data URI and does not violate the Content Security Policy.

Here’s an example of how you can base64 encode the font:

@font-face {
    font-family: 'CustomFont';
    src: url(data:font/woff;base64,xxxxxxxxxxxxx) format('woff');
}

In the above example, replace ‘xxxxxxxxxxxxx’ with the base64 encoded font data. This will allow the font to be loaded without violating the Content Security Policy.

By implementing one of these solutions, you should be able to resolve the error “Refused to load the font ‘data:font/woff…..’it violates the following Content Security Policy directive: ‘default-src ‘self”. Note that ‘font-src’”. Remember to choose the solution that best fits your specific requirements and security needs.

Happy coding!