Proper PoW, unified verification WS etc

frontend/src/components/RemoteAuthLinkModal.vue

@@ -108,6 +108,7 @@ import QRCode from 'qrcode/lib/browser'
 import aWebSocket from '@/utils/awaitable-websocket'
 import { getSettings } from '@/utils/settings'
 import { formatDate } from '@/utils/helpers'
+import { solvePoW } from '@/utils/pow'
 
 const props = defineProps({
   active: { type: Boolean, default: false },
@@ -152,6 +153,18 @@ async function startRemoteAuth() {
 
     ws = await aWebSocket(wsUrl)
 
+    // First message is PoW challenge
+    const powChallenge = await ws.receive_json()
+    if (powChallenge.pow) {
+      const challenge = Uint8Array.from(atob(powChallenge.pow.challenge), c => c.charCodeAt(0))
+      const powStart = performance.now()
+      const nonce = await solvePoW(challenge, powChallenge.pow.bits)
+      const powTime = performance.now() - powStart
+      const nonceVal = nonce.reduce((acc, b, i) => acc + BigInt(b) * (1n << BigInt(i * 8)), 0n)
+      console.log(`PoW solved: ${Number(nonceVal)} iterations in ${(powTime / 1000).toFixed(3)}s (${(powTime / Number(nonceVal)).toFixed(3)}ms/iter)`)
+      ws.send_json({ pow: btoa(String.fromCharCode(...nonce)) })
+    }
+
     // Receive the remote auth token, pairing code, and URL
     const res = await ws.receive_json()