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Detect static securecookies to trivialize more rules #16029

Merged
merged 10 commits into from
Aug 22, 2018
38 changes: 37 additions & 1 deletion utils/trivialize-rules/trivialize-rules.js
Original file line number Diff line number Diff line change
Expand Up @@ -99,6 +99,7 @@ files.fork().zipAll([ sources.fork(), rules ]).map(([name, source, ruleset]) =>
const fail = createTag('FAIL', chalk.red, console.error);

let targets = ruleset.target.map(target => target.$.host);
let securecookies = ruleset.securecookie ? ruleset.securecookie.map(sc => sc.$) : new Array();
let rules = ruleset.rule.map(rule => rule.$);

if (rules.length === 1 && isTrivial(rules[0])) {
Expand Down Expand Up @@ -181,8 +182,43 @@ files.fork().zipAll([ sources.fork(), rules ]).map(([name, source, ruleset]) =>

domains = Array.from(domains);

function isStaticCookie(securecookie) {
if (securecookie.host === '.+' && securecookie.name === '.+') {
return true;
}

if (!securecookie.host.startsWith('^') || !securecookie.host.endsWith('$')) {
return false;
}

let localDomains = new Set();

try {
explodeRegExp(securecookie.host, domain => {
if (domain.startsWith('.')) {
domain = domain.slice(1);
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Is this sufficient munging to ensure it matches the target domains?
If not, at worst it will not match and result in a false result, which isn't terrible but not desirable.

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@cschanaj cschanaj Jul 12, 2018

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@Hainish this should be good enough. As mentioned in #16029 (comment), securecookie.host only match cookie.domain if there is a rule covers cookie.domain. Given the target are trivial, cookie.domain cannot be anything other than domain.example.com and .domain.example.com for a securecookie rule to works. With condition (1) effective, securecookie.host should explode to either one of them. Otherwise, the securecookie will never be applied (dangling rules?) under the current implementation.

With the above logic in mind, I have also add 4bbd731 to remove some of these securecookie rules that will never be effective.

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IMHO, it would be great to have #15998 and #16000 merged before running this against the master.

}
localDomains.add(domain);
});
} catch (e) {
if (!(e instanceof UnsupportedRegExp)) {
throw e;
}
warn`Unsupported regexp part ${e.message} while traversing securecookie : ${JSON.stringify(securecookie)}`;
return false;
}

for (const domain of localDomains) {
if (domains.indexOf(domain) === -1) {
warn`Ruleset does not cover target ${domain} for securecookie : ${JSON.stringify(securecookie)}`;
return false;
}
}
return true;
}

if (domains.slice().sort().join('\n') !== targets.sort().join('\n')) {
if (ruleset.securecookie) {
if (securecookies.length > 0 && !securecookies.every(isStaticCookie)) {
return;
}

Expand Down