Various improvements to remote link login. PoW algorithm tuned. Added base64url and helper modules.

frontend/src/components/RemoteAuthLinkModal.vue

@@ -106,6 +106,7 @@
 import { ref, computed, watch, nextTick, onMounted, onUnmounted } from 'vue'
 import QRCode from 'qrcode/lib/browser'
 import aWebSocket from '@/utils/awaitable-websocket'
+import { dec as b64dec, enc as b64enc } from '@/utils/base64url'
 import { getSettings } from '@/utils/settings'
 import { formatDate } from '@/utils/helpers'
 import { solvePoW } from '@/utils/pow'
@@ -156,13 +157,12 @@ async function startRemoteAuth() {
     // 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 challenge = b64dec(powChallenge.pow.challenge)
       const powStart = performance.now()
-      const nonce = await solvePoW(challenge, powChallenge.pow.bits)
+      const nonces = await solvePoW(challenge, powChallenge.pow.work)
       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)) })
+      console.log(`PoW solved: ${powChallenge.pow.work} work units in ${(powTime / 1000).toFixed(3)}s`)
+      ws.send_json({ pow: b64enc(nonces) })
     }
 
     // Receive the remote auth token, pairing code, and URL