Data loss prevention
Protect sensitive data to prevent data loss, and send alerts to a webhooks server in the event of a data breach.
const DEBUG = trueconst SOME_HOOK_SERVER = "https://webhook.flow-wolf.io/hook"/** * Alert a data breach by posting to a webhook server */async function postDataBreach(request) { const trueClientIp = request.headers.get("cf-connecting-ip") const epoch = new Date().getTime() const body = { ip: trueClientIp, time: epoch, request: request } const init = { body: JSON.stringify(body), method: "POST", headers: { "content-type": "application/json;charset=UTF-8" }, } return await fetch(SOME_HOOK_SERVER, init)}/** * Define personal data with regular expressions. * Respond with block if credit card data, and strip * emails and phone numbers from the response. * Execution will be limited to MIME type "text/*". */async function handleRequest(request) { const response = await fetch(request)
// Return origin response, if response wasn’t text const contentType = response.headers.get("content-type") || "" if (!contentType.toLowerCase().includes("text/")) { return response }
let text = await response.text()
// When debugging replace the response // from the origin with an email text = DEBUG ? text.replace("You may use this", "me@example.com may use this") : text
const sensitiveRegexsMap = { creditCard: String.raw`\b(?:4[0-9]{12}(?:[0-9]{3})?|(?:5[1-5][0-9]{2}|222[1-9]|22[3-9][0-9]|2[3-6][0-9]{2}|27[01][0-9]|2720)[0-9]{12}|3[47][0-9]{13}|3(?:0[0-5]|[68][0-9])[0-9]{11}|6(?:011|5[0-9]{2})[0-9]{12}|(?:2131|1800|35\d{3})\d{11})\b`, email: String.raw`\b[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,}\b`, phone: String.raw`\b07\d{9}\b` }
for (const kind in sensitiveRegexsMap) { const sensitiveRegex = new RegExp(sensitiveRegexsMap[kind], "ig") const match = await sensitiveRegex.test(text) if (match) { // Alert a data breach await postDataBreach(request)
// Respond with a block if credit card, // otherwise replace sensitive text with `*`s return kind === "creditCard" ? new Response(kind + " found\nForbidden\n", { status: 403, statusText: "Forbidden" }) : new Response(text.replace(sensitiveRegex, "**********"), response) } } return new Response(text, response)}
addEventListener("fetch", event => { event.respondWith(handleRequest(event.request))})