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/**
* Hachette injecting policy to page using webRequest
*
* Copyright (C) 2021 Wojtek Kosior
* Copyright (C) 2021 jahoti
* Redistribution terms are gathered in the `copyright' file.
*/
/*
* IMPORTS_START
* IMPORT sign_data
* IMPORT extract_signed
* IMPORT sanitize_csp_header
* IMPORT csp_rule
* IMPORT is_csp_header_name
* IMPORTS_END
*/
function inject_csp_headers(details, headers, policy)
{
const url = details.url;
let orig_csp_headers;
let old_signature;
let hachette_header;
for (const header of headers.filter(h => h.name === "x-hachette")) {
const match = /^([^%])(%.*)$/.exec(header.value);
if (!match)
continue;
const old_data = extract_signed(...match.splice(1, 2), [[0]]);
if (!old_data || old_data.url !== url)
continue;
/* Confirmed- it's the originals, smuggled in! */
orig_csp_headers = old_data.csp_headers;
old_signature = old_data.policy_sig;
hachette_header = header;
break;
}
if (!hachette_header) {
hachette_header = {name: "x-hachette"};
headers.push(hachette_header);
}
orig_csp_headers = orig_csp_headers ||
headers.filter(h => is_csp_header_name(h.name));
/* When blocking remove report-only CSP headers that snitch on us. */
headers = headers.filter(h => !is_csp_header_name(h.name, !policy.allow));
if (old_signature)
headers = headers.filter(h => h.name.search(old_signature) === -1);
const sanitizer = h => sanitize_csp_header(h, policy);
headers.push(...orig_csp_headers.map(sanitizer));
const policy_str = encodeURIComponent(JSON.stringify(policy));
const policy_sig = sign_data(policy_str, new Date());
const later_30sec = new Date(new Date().getTime() + 30000).toGMTString();
headers.push({
name: "Set-Cookie",
value: `hachette-${policy_sig}=${policy_str}; Expires=${later_30sec};`
});
/*
* Smuggle in the signature and the original CSP headers for future use.
* These are signed with a time of 0, as it's not clear there is a limit on
* how long Firefox might retain headers in the cache.
*/
let hachette_data = {csp_headers: orig_csp_headers, policy_sig, url};
hachette_data = encodeURIComponent(JSON.stringify(hachette_data));
hachette_header.value = sign_data(hachette_data, 0) + hachette_data;
/* To ensure there is a CSP header if required */
if (!policy.allow)
headers.push({
name: "content-security-policy",
value: csp_rule(policy.nonce)
});
return headers;
}
/*
* EXPORTS_START
* EXPORT inject_csp_headers
* EXPORTS_END
*/
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