70 lines
2.0 KiB
JavaScript
70 lines
2.0 KiB
JavaScript
import { createHmac } from 'node:crypto'
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import { extractUrls } from '../../../lib/md'
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const imgProxyEnabled = process.env.NODE_ENV === 'production' ||
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(process.env.NEXT_PUBLIC_IMGPROXY_URL && process.env.IMGPROXY_SALT && process.env.IMGPROXY_KEY)
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if (!imgProxyEnabled) {
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console.warn('IMGPROXY_* env vars not set, imgproxy calls are no-ops now')
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}
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const IMGPROXY_URL = process.env.NEXT_PUBLIC_IMGPROXY_URL
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const IMGPROXY_SALT = process.env.IMGPROXY_SALT
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const IMGPROXY_KEY = process.env.IMGPROXY_KEY
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const hexDecode = (hex) => Buffer.from(hex, 'hex')
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const sign = (target) => {
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// https://github.com/imgproxy/imgproxy/blob/master/examples/signature.js
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const hmac = createHmac('sha256', hexDecode(IMGPROXY_KEY))
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hmac.update(hexDecode(IMGPROXY_SALT))
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hmac.update(target)
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return hmac.digest('base64url')
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}
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const createImageProxyUrl = url => {
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const processingOptions = '/rs:fit:600:500:0/g:no'
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const b64Url = Buffer.from(url, 'utf-8').toString('base64url')
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const target = `${processingOptions}/${b64Url}`
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const signature = sign(target)
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return `${IMGPROXY_URL}${signature}${target}`
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}
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async function fetchWithTimeout (resource, { timeout = 1000, ...options } = {}) {
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const controller = new AbortController()
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const id = setTimeout(() => controller.abort(), timeout)
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const response = await fetch(resource, {
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...options,
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signal: controller.signal
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})
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clearTimeout(id)
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return response
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}
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const isImageURL = async url => {
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// https://stackoverflow.com/a/68118683
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try {
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const res = await fetchWithTimeout(url, { method: 'HEAD' })
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const buf = await res.blob()
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return buf.type.startsWith('image/')
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} catch (err) {
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console.log(url, err)
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return false
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}
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}
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export const proxyImages = async text => {
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if (!imgProxyEnabled) return text
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const urls = extractUrls(text)
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for (const url of urls) {
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if (url.startsWith(IMGPROXY_URL)) continue
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if (!(await isImageURL(url))) continue
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const proxyUrl = createImageProxyUrl(url)
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text = text.replaceAll(url, proxyUrl)
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}
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return text
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}
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