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Code Issues Releases Wiki Activity

Fix exploit and add tests for proxy URL validator

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This commit is contained in:
Cadence Ember 2020-06-19 17:57:34 +12:00
parent 10c913a919
commit 6e1e5e6996
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GPG Key ID: 128B99B1B74A6412
3 changed files with 82 additions and 22 deletions
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32
src/lib/utils/proxyurl.js
View File

@ -1,3 +1,31 @@
/**
* Check that a host is part of Instagram's CDN.
* @param {string} host
*/
function verifyHost(host) {
const domains = ["fbcdn.net", "cdninstagram.com"]
return domains.some(against => host === against || host.endsWith("." + against))
}
/**
* Check that a resource is on Instagram.
* @param {URL} completeURL
*/
function verifyURL(completeURL) {
const params = completeURL.searchParams
if (!params.get("url")) return {status: "fail", value: [400, "Must supply `url` query parameter"]}
try {
var url = new URL(params.get("url"))
} catch (e) {
return {status: "fail", value: [400, "`url` query parameter is not a valid URL"]}
}
// check url protocol
if (url.protocol !== "https:") return {status: "fail", value: [400, "URL protocol must be `https:`"]}
// check url host
if (!verifyHost(url.host)) return {status: "fail", value: [400, "URL host is not allowed"]}
return {status: "ok", url}
}
function proxyImage(url, width) {
const params = new URLSearchParams()
if (width) params.set("width", width)
@ -23,7 +51,7 @@ function proxyVideo(url) {
*/
function proxyExtendedOwner(owner) {
const clone = {...owner}
clone.profile_pic_url = proxyImage(clone.profile_pic_url)
clone.profile_pic_url = proxyProfilePic(clone.profile_pic_url, clone.id)
return clone
}
@ -31,3 +59,5 @@ module.exports.proxyImage = proxyImage
module.exports.proxyProfilePic = proxyProfilePic
module.exports.proxyVideo = proxyVideo
module.exports.proxyExtendedOwner = proxyExtendedOwner
module.exports.verifyHost = verifyHost
module.exports.verifyURL = verifyURL

21
src/site/api/proxy.js
View File

@ -3,27 +3,10 @@ const sharp = require("sharp")
const constants = require("../../lib/constants")
const collectors = require("../../lib/collectors")
const {request} = require("../../lib/utils/request")
const {verifyURL} = require("../../lib/utils/proxyurl")
const db = require("../../lib/db")
require("../../lib/testimports")(constants, request, db)
require("../../lib/testimports")(constants, request, db, verifyURL)
/**
* Check that a resource is on Instagram.
* @param {URL} completeURL
*/
function verifyURL(completeURL) {
const params = completeURL.searchParams
if (!params.get("url")) return {status: "fail", value: [400, "Must supply `url` query parameter"]}
try {
var url = new URL(params.get("url"))
} catch (e) {
return {status: "fail", value: [400, "`url` query parameter is not a valid URL"]}
}
// check url protocol
if (url.protocol !== "https:") return {status: "fail", value: [400, "URL protocol must be `https:`"]}
// check url host
if (!["fbcdn.net", "cdninstagram.com"].some(host => url.host.endsWith(host))) return {status: "fail", value: [400, "URL host is not allowed"]}
return {status: "ok", url}
}
function statusCodeIsAcceptable(status) {
return (status >= 200 && status < 300) || status === 304

51
test/proxyurl.js
View File

@ -1,5 +1,5 @@
const tap = require("tap")
const {proxyImage, proxyVideo, proxyExtendedOwner} = require("../src/lib/utils/proxyurl")
const {proxyImage, proxyVideo, proxyProfilePic, proxyExtendedOwner, verifyHost, verifyURL} = require("../src/lib/utils/proxyurl")
tap.equal(
proxyImage("https://scontent-syd2-1.cdninstagram.com/v/t51.2885-15/e35/p1080x1080/83429487_106792960779790_3699017977444758529_n.jpg?_nc_ht=scontent-syd2-1.cdninstagram.com&_nc_cat=1&_nc_ohc=YYmv6lkrblAAX_9u9Kt&oh=81a70f2b92e70873b5ebc9253e7df937&oe=5EBC230A"),
@ -29,7 +29,7 @@ tap.test("proxy extended owner", childTest => {
username: "instagram",
is_verified: true,
full_name: "Instagram",
profile_pic_url: "/imageproxy?url=https%3A%2F%2Fscontent-syd2-1.cdninstagram.com%2Fv%2Ft51.2885-19%2Fs150x150%2F59381178_2348911458724961_5863612957363011584_n.jpg%3F_nc_ht%3Dscontent-syd2-1.cdninstagram.com%26_nc_ohc%3DTrMM-1zPSA4AX857GJB%26oh%3D15b843b0c1033784492b64b1170cd048%26oe%3D5EC9125D"
profile_pic_url: "/imageproxy?userID=25025320&url=https%3A%2F%2Fscontent-syd2-1.cdninstagram.com%2Fv%2Ft51.2885-19%2Fs150x150%2F59381178_2348911458724961_5863612957363011584_n.jpg%3F_nc_ht%3Dscontent-syd2-1.cdninstagram.com%26_nc_ohc%3DTrMM-1zPSA4AX857GJB%26oh%3D15b843b0c1033784492b64b1170cd048%26oe%3D5EC9125D"
},
"owner was proxied"
)
@ -40,3 +40,50 @@ tap.test("proxy extended owner", childTest => {
)
childTest.end()
})
tap.test("check host validation", async childTest => {
{
const url = new URL("https://instance.tld/imageproxy?width=320&url=https%3A%2F%2Fscontent-syd2-1.cdninstagram.com%2Fv%2Ft51.2885-15%2Fe35%2Fc0.180.1440.1440a%2Fs320x320%2F89848538_212928513111869_8518822308890932076_n.jpg%3F_nc_ht%3Dscontent-syd2-1.cdninstagram.com%26_nc_cat%3D105%26_nc_ohc%3DjPxGnFMF_ZoAX_Q_-jf%26oh%3D018fd6d752e15dedbdf132e004356c98%26oe%3D5F178951")
childTest.equal(verifyURL(url).status, "ok", "real cdninstagram syd region")
}
{
const url = new URL("https://instance.tld/imageproxy?url=https%3A%2F%2Fscontent-amt2-1.cdninstagram.com%2Fv%2Ft51.2885-15%2Fe35%2Fp1080x1080%2F101427269_544579909564468_979862184432362192_n.jpg%3F_nc_ht%3Dscontent-amt2-1.cdninstagram.com%26_nc_cat%3D1%26_nc_ohc%3DF-j-3JXkOVgAX_MMJHb%26oh%3De9e0d4ab65a53c15926349bceea9f09d%26oe%3D5F14C4F3")
childTest.equal(verifyURL(url).status, "ok", "real cdninstagram amt region")
}
{
const url = new URL("https://instance.tld/imageproxy?url=https%3A%2F%2Fscontent-frx5-1.cdninstagram.com%2Fv%2Ft51.2885-19%2Fs150x150%2F29090066_159271188110124_1152068159029641216_n.jpg%3F_nc_ht%3Dscontent-frx5-1.cdninstagram.com%26_nc_ohc%3DDC7QZiTfNtsAX_ZN33H%26oh%3D77fb5103f058121f7afac07e8e11af44%26oe%3D5F153193")
childTest.equal(verifyURL(url).status, "ok", "real cdninstagram frx region")
}
{
const url = new URL("https://instance.tld/imageproxy?url=wow im cool")
childTest.same(
verifyURL(url),
{
status: "fail",
value: [400, "`url` query parameter is not a valid URL"],
},
"invalid url"
)
}
{
const url = new URL("https://instance.tld/imageproxy?url=http%3A%2F%2Fscontent-frx5-1.cdninstagram.com%2Fv%2Ft51.2885-19%2Fs150x150%2F29090066_159271188110124_1152068159029641216_n.jpg%3F_nc_ht%3Dscontent-frx5-1.cdninstagram.com%26_nc_ohc%3DDC7QZiTfNtsAX_ZN33H%26oh%3D77fb5103f058121f7afac07e8e11af44%26oe%3D5F153193")
childTest.same(
verifyURL(url),
{
status: "fail",
value: [400, "URL protocol must be `https:`"]
},
"http protocol"
)
}
{
const url = new URL("https://instance.tld/imageproxy?url=https%3A%2F%2Fnotcdninstagram.com")
childTest.same(
verifyURL(url),
{
status: "fail",
value: [400, "URL host is not allowed"]
}
)
}
})