From f558a35d3d4ae99973d5633efe7b3cc26070c134 Mon Sep 17 00:00:00 2001
From: Roberto Hidalgo <un@rob.mx>
Date: Wed, 4 Jan 2023 15:55:52 -0600
Subject: [PATCH] padding?

---
 internal/server/static/webauthn.js | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/internal/server/static/webauthn.js b/internal/server/static/webauthn.js
index 82b4c3e..11aafea 100644
--- a/internal/server/static/webauthn.js
+++ b/internal/server/static/webauthn.js
@@ -66,12 +66,13 @@ async function register(challenge) {
   console.dir(parsed)
 
   console.info("webauthn: issuing credential creation request to browser")
-  let credential
-  try {
-    credential = await webauthnJSON.create(parsed);
-  } catch (err) {
-    console.error("sigh", err)
-    throw err
+  let credential = await webauthnJSON.create(parsed);
+  let missing = 4 - (credential.response.clientDataJSON.length % 4)
+  if (missing != 0) {
+    while (missing > 0) {
+      credential.response.clientDataJSON += "="
+      missing -= 1
+    }
   }
   console.debug(`webauthn: registering credentials with server: ${JSON.stringify(credential)}`)
 
@@ -108,6 +109,13 @@ async function login(challenge, target, config) {
 
   console.debug("webauthn: fetching stored client credentials")
   let credential = await webauthnJSON.get(parsed);
+  let missing = 4 - (credential.response.clientDataJSON.length % 4)
+  if (missing != 0) {
+    while (missing > 0) {
+      credential.response.clientDataJSON += "="
+      missing -= 1
+    }
+  }
 
   config.credentials = "include"
   config.headers = config.headers || {}