hashof a script or style can be used to allow it .
Suppose we have the following script on our page:
doSomething(); you will get the value:
Finally we can add the hash to our script-src directive to allow it to execute via our Content-Security-Policy header:
The CSP Level 2 specification allows
The easiest way to generate it is to just open the developer tools console and it will output what the expected hash of your script was in the console error message.
You can also use tools such as openssl to generate it, whitespace is not ignored.
Here is an example using openssl, which will be installed by default on most mac or linux systems:
echo -n 'doSomething();' | openssl sha256 -binary | openssl base64
There are a three common reasons your CSP hash might not be working:
script-src sha256-abc123;you need to wrap it in single quotes, for example:
hash source list directive was added to CSP Level 2. This means that support has existed since 2015 in Chrome and Firefox, Safari 10+ or Edge 15+.
It is not supported at all in Internet Explorer, you need to use the Edge browser instead.
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