2 step register

5 files changed, 72 insertions, 13 deletions

diff --git a/src/lib/deriveAuthKey.ts b/src/lib/deriveAuthKey.ts
index 9215b515..eb498e0a 100644
--- a/src/lib/deriveAuthKey.ts
+++ b/src/lib/deriveAuthKey.ts
@@ -1,7 +1,6 @@
 import { scryptAsync } from "@noble/hashes/scrypt.js";
 import { bytesToHex } from "@noble/hashes/utils.js";
 import { getPublicKey } from "nostr-tools";
-import { rememberPrfKey, defaultRememberForMs } from "$lib/passwordCache";
 
 export async function deriveAuthKeypair(username: string, password: string) {
   const salt = `coinos:auth:${username.toLowerCase().replace(/\s/g, "")}`;
@@ -17,7 +16,5 @@ export async function deriveWalletEntropy(sk: Uint8Array): Promise<ArrayBuffer>
   const sigBytes = new Uint8Array(signed.sig.length / 2);
   for (let i = 0; i < signed.sig.length; i += 2)
     sigBytes[i / 2] = parseInt(signed.sig.slice(i, i + 2), 16);
-  const entropy = await crypto.subtle.digest("SHA-256", sigBytes);
-  rememberPrfKey(entropy, defaultRememberForMs);
-  return entropy;
+  return crypto.subtle.digest("SHA-256", sigBytes);
 }
diff --git a/src/lib/keyWrapping.ts b/src/lib/keyWrapping.ts
new file mode 100644
index 00000000..b176e741
--- /dev/null
+++ b/src/lib/keyWrapping.ts
@@ -0,0 +1,61 @@
+import { prfEncrypt, prfDecrypt } from "$lib/crypto";
+import { rememberPrfKey, defaultRememberForMs, getCachedPrfKey } from "$lib/passwordCache";
+import { post } from "$lib/utils";
+
+export function generateCanonicalKey(): ArrayBuffer {
+  return crypto.getRandomValues(new Uint8Array(32)).buffer as ArrayBuffer;
+}
+
+export async function wrapCanonicalKey(
+  wrappingKey: ArrayBuffer,
+  canonicalKey: ArrayBuffer,
+): Promise<string> {
+  return prfEncrypt(wrappingKey, new Uint8Array(canonicalKey));
+}
+
+export async function unwrapCanonicalKey(
+  wrappingKey: ArrayBuffer,
+  encrypted: string,
+): Promise<ArrayBuffer> {
+  const bytes = await prfDecrypt(wrappingKey, encrypted);
+  return bytes.buffer as ArrayBuffer;
+}
+
+export async function resolveCanonicalKey(
+  methodId: string,
+  wrappingKey: ArrayBuffer,
+  encryptedKeys: Record<string, string> | null | undefined,
+  oldPrfKey: ArrayBuffer,
+): Promise<{ canonicalKey: ArrayBuffer; encryptedKeys: Record<string, string> }> {
+  if (encryptedKeys && encryptedKeys[methodId]) {
+    const canonicalKey = await unwrapCanonicalKey(wrappingKey, encryptedKeys[methodId]);
+    rememberPrfKey(canonicalKey, defaultRememberForMs);
+    return { canonicalKey, encryptedKeys };
+  }
+
+  // Migration: old PRF key becomes canonical key
+  const canonicalKey = oldPrfKey;
+  const wrapped = await wrapCanonicalKey(wrappingKey, canonicalKey);
+  const updated = { ...(encryptedKeys || {}), [methodId]: wrapped };
+  await saveEncryptedKeys(updated);
+  rememberPrfKey(canonicalKey, defaultRememberForMs);
+  return { canonicalKey, encryptedKeys: updated };
+}
+
+export async function saveEncryptedKeys(
+  encryptedKeys: Record<string, string>,
+): Promise<void> {
+  await post("/post/user", { encryptedKeys });
+}
+
+export function passwordMethodId(): string {
+  return "password";
+}
+
+export function passkeyMethodId(credentialId: string): string {
+  return `passkey:${credentialId}`;
+}
+
+export function nostrMethodId(pubkey: string): string {
+  return `nostr:${pubkey}`;
+}
diff --git a/src/lib/passkey.ts b/src/lib/passkey.ts
index 053eb06a..7c9e98cc 100644
--- a/src/lib/passkey.ts
+++ b/src/lib/passkey.ts
@@ -10,12 +10,15 @@ function authHeader(token: string) {
   return { authorization: `Bearer ${token}` };
 }
 
-export async function registerPasskey(token?: string): Promise<ArrayBuffer> {
+export async function registerPasskey(
+  token?: string,
+): Promise<{ prfKey: ArrayBuffer; credentialId: string }> {
   const headers = token ? authHeader(token) : undefined;
   const options = await post("/passkey/register/options", {}, headers);
   const registration = await startRegistration({ optionsJSON: options });
   await post("/passkey/register/verify", registration, headers);
-  return deriveKey(registration.id);
+  const prfKey = await deriveKey(registration.id);
+  return { prfKey, credentialId: registration.id };
 }
 
 export async function loginWithPasskey(): Promise<{
diff --git a/src/lib/utils.ts b/src/lib/utils.ts
index eee6903e..e37556e3 100644
--- a/src/lib/utils.ts
+++ b/src/lib/utils.ts
@@ -214,6 +214,8 @@ export const login = async (
       });
     } catch {}
   }
+
+  return u;
 };
 
 export const auth = (cookies) => ({
diff --git a/src/lib/walletEntropy.ts b/src/lib/walletEntropy.ts
index 25bd49b8..95b3e903 100644
--- a/src/lib/walletEntropy.ts
+++ b/src/lib/walletEntropy.ts
@@ -1,5 +1,5 @@
 import { browser } from "$app/environment";
-import { getCachedPrfKey, rememberPrfKey, defaultRememberForMs } from "$lib/passwordCache";
+import { getCachedPrfKey } from "$lib/passwordCache";
 
 const DERIVATION_EVENT = {
   kind: 1,
@@ -27,9 +27,7 @@ export async function tryDeriveFromNsec(): Promise<ArrayBuffer | null> {
     const { nip19, finalizeEvent } = await import("nostr-tools");
     const sk = nip19.decode(nsec).data as Uint8Array;
     const signed = finalizeEvent({ ...DERIVATION_EVENT } as any, sk);
-    const entropy = await hashSignature(signed.sig);
-    rememberPrfKey(entropy, defaultRememberForMs);
-    return entropy;
+    return await hashSignature(signed.sig);
   } catch (e) {
     console.log("nsec entropy derivation failed", e);
     return null;
@@ -60,7 +58,5 @@ export async function deriveNostrEntropy(): Promise<ArrayBuffer> {
 
   const { sign } = await import("$lib/nostr");
   const signed = await sign({ ...DERIVATION_EVENT });
-  const entropy = await hashSignature(signed.sig);
-  rememberPrfKey(entropy, defaultRememberForMs);
-  return entropy;
+  return hashSignature(signed.sig);
 }