ampprojectAMP-Toolbox Script CSP
Calculates the Content Security Policy (CSP)
hash for the given script in the format expected by amp-script.
CSP is required when using amp-script with inline or cross-origin scripts.
Usage
Install via:
$ npm install @ampproject/toolbox-script-cspUsing the module
The module exposes a single function, calculateHash(src, options?).
src can be either a string (in which case UTF8 encoding is assumed) or a
DataView
such as a Buffer.
options is used to override the default options.
Options
algorithmoverrides the hashing algorithm to use. Currently, the only algorithm supported byamp-scriptissha384which is the default value.
Example
Here is an example on how to use the calculateHash function to generate an
amp-script CSP header.
Note that both leading and trailing whitespace is included in calculating the hash and must exactly match the whitespace used in the inline script.
const {calculateHash} = require('@ampproject/toolbox-script-csp');
const script = `
const subject = 'world';
console.log('Hello, ' + subject);
`;
const hash = calculateHash(script);
console.log(hash); // sha384-xRxb5sv13at6tVgZET4JLmf89TSZP10HjCGXVqO9bKWVXB0asV2jLrsDN8v4zX6jThe generated hash can be used in a <meta> tag this way:
<!doctype html>
<html ⚡>
<head>
...
<meta name="amp-script-src" content="sha384-xRxb5sv13at6tVgZET4JLmf89TSZP10HjCGXVqO9bKWVXB0asV2jLrsDN8v4zX6j">
</head>
<body>
...
<amp-script layout="container" script="example"></amp-script>
<script id="example" type="text/plain" target="amp-script">
const subject = 'world';
console.log('Hello, ' + subject);
</script>
</body>
</html>