cadence/out-of-your-element
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Store Discord media proxy hashes in the database

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Cadence Ember 2024-09-22 15:53:58 +12:00
parent f3eb1fbeb3
commit 06f502dd89
2 changed files with 19 additions and 1 deletions
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10
src/discord/utils.js
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@ -5,6 +5,13 @@ const assert = require("assert").strict
const {reg} = require("../matrix/read-registration")
const {db} = require("../passthrough")
/** @type {import("xxhash-wasm").XXHashAPI} */ // @ts-ignore
let hasher = null
// @ts-ignore
require("xxhash-wasm")().then(h => hasher = h)
const EPOCH = 1420070400000
/**
@ -123,6 +130,9 @@ function timestampToSnowflakeInexact(timestamp) {
function getPublicUrlForCdn(url) {
const match = url.match(/https:\/\/(cdn|media)\.discordapp\.(?:com|net)\/attachments\/([0-9]+)\/([0-9]+)\/([-A-Za-z0-9_.,]+)/)
if (!match) return url
const unsignedHash = hasher.h64(match[3]) // attachment ID
const signedHash = unsignedHash - 0x8000000000000000n // shifting down to signed 64-bit range
db.prepare("INSERT OR IGNORE INTO media_proxy (permitted_hash) VALUES (?)").run(signedHash)
return `${reg.ooye.bridge_origin}/download/discord${match[1]}/${match[2]}/${match[3]}/${match[4]}`
}

10
src/web/routes/download-discord.js
View file

@ -4,6 +4,11 @@ const assert = require("assert/strict")
const {defineEventHandler, getValidatedRouterParams, sendRedirect, createError} = require("h3")
const {z} = require("zod")
/** @type {import("xxhash-wasm").XXHashAPI} */ // @ts-ignore
let hasher = null
// @ts-ignore
require("xxhash-wasm")().then(h => hasher = h)
const {discord, as, select} = require("../../passthrough")
const schema = {
@ -31,7 +36,10 @@ function defineMediaProxyHandler(domain) {
return defineEventHandler(async event => {
const params = await getValidatedRouterParams(event, schema.params.parse)
const row = select("channel_room", "channel_id", {channel_id: params.channel_id}).get()
const unsignedHash = hasher.h64(params.attachment_id)
const signedHash = unsignedHash - 0x8000000000000000n // shifting down to signed 64-bit range
const row = select("media_proxy", "permitted_hash", {permitted_hash: signedHash}).get()
if (row == null) {
throw createError({
status: 403,