vercel-og-with-tweaks/pages/api/encrypted.tsx

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2022-11-04 23:02:31 +00:00
// This function verifies the token to prevent generating images with random
// parameters (`id`).
// Check pages/encrypted/[id].tsx for more info.
import { ImageResponse } from '@vercel/og'
import { NextRequest } from 'next/server'
export const config = {
runtime: 'experimental-edge',
}
const key = crypto.subtle.importKey(
'raw',
new TextEncoder().encode('my_secret'),
{ name: 'HMAC', hash: { name: 'SHA-256' } },
false,
['sign']
)
function toHex(arrayBuffer) {
return Array.prototype.map
.call(new Uint8Array(arrayBuffer), (n) => n.toString(16).padStart(2, '0'))
.join('')
}
export default async function handler(req: NextRequest) {
const { searchParams } = req.nextUrl
const id = searchParams.get('id')
const token = searchParams.get('token')
const verifyToken = toHex(
await crypto.subtle.sign(
'HMAC',
await key,
new TextEncoder().encode(JSON.stringify({ id }))
)
)
if (token !== verifyToken) {
return new Response('Invalid token.', { status: 401 })
}
return new ImageResponse(
(
<div
style={{
display: 'flex',
fontSize: 40,
color: 'black',
background: 'white',
width: '100%',
height: '100%',
padding: '50px 200px',
textAlign: 'center',
justifyContent: 'center',
alignContent: 'center',
}}
>
<h1>Card generated, id={id}.</h1>
</div>
),
{
width: 1200,
height: 630,
}
)
}