[EC-598] fix: invalid signature due to double hashing

libs/common/src/webauthn/services/fido2-authenticator.service.spec.ts

@@ -34,19 +34,6 @@ describe("FidoAuthenticatorService", () => {
     cipherService = mock<CipherService>();
     userInterface = mock<Fido2UserInterfaceService>();
     authenticator = new Fido2AuthenticatorService(cipherService, userInterface);
-
-    // crypto.subtle.importKey doesn't work properly in jest, so we need to mock it with new keys.
-    const privateKey = (
-      await crypto.subtle.generateKey(
-        {
-          name: "ECDSA",
-          namedCurve: "P-256",
-        },
-        true,
-        ["sign"]
-      )
-    ).privateKey;
-    crypto.subtle.importKey = jest.fn().mockResolvedValue(privateKey);
   });
 
   describe("makeCredential", () => {
@@ -648,16 +635,24 @@ describe("FidoAuthenticatorService", () => {
       describe(`assertion of ${
         residentKey ? "discoverable" : "non-discoverable"
       } credential`, () => {
+        let keyPair: CryptoKeyPair;
         let credentialIds: string[];
         let selectedCredentialId: string;
         let ciphers: CipherView[];
         let params: Fido2AuthenticatorGetAssertionParams;
 
         beforeEach(async () => {
+          keyPair = await createKeyPair();
           credentialIds = [Utils.newGuid(), Utils.newGuid()];
+          const keyValue = Fido2Utils.bufferToString(
+            await crypto.subtle.exportKey("pkcs8", keyPair.privateKey)
+          );
           if (residentKey) {
             ciphers = credentialIds.map((id) =>
-              createCipherView({ type: CipherType.Fido2Key }, { rpId: RpId, counter: 9000 })
+              createCipherView(
+                { type: CipherType.Fido2Key },
+                { rpId: RpId, counter: 9000, keyValue }
+              )
             );
             selectedCredentialId = ciphers[0].id;
             params = await createParams({
@@ -723,8 +718,20 @@ describe("FidoAuthenticatorService", () => {
           );
           expect(flags).toEqual(new Uint8Array([0b00000001])); // UP = true
           expect(counter).toEqual(new Uint8Array([0, 0, 0x23, 0x29])); // 9001 in hex
-          // Signatures are non-deterministic, and webcrypto can't verify DER signature format
-          // expect(result.signature).toMatchSnapshot();
+
+          // Verify signature
+          // TODO: Cannot verify signature because it has been converted into DER format
+          // const sigBase = new Uint8Array([
+          //   ...result.authenticatorData,
+          //   ...Fido2Utils.bufferSourceToUint8Array(params.hash),
+          // ]);
+          // const isValidSignature = await crypto.subtle.verify(
+          //   { name: "ECDSA", hash: { name: "SHA-256" } },
+          //   keyPair.publicKey,
+          //   result.signature,
+          //   sigBase
+          // );
+          // expect(isValidSignature).toBe(true);
         });
 
         /** Spec: If any error occurred while generating the assertion signature, return an error code equivalent to "UnknownError" and terminate the operation. */
@@ -804,3 +811,14 @@ async function createClientDataHash() {
 function randomBytes(length: number) {
   return new Uint8Array(Array.from({ length }, (_, k) => k % 255));
 }
+
+async function createKeyPair() {
+  return await crypto.subtle.generateKey(
+    {
+      name: "ECDSA",
+      namedCurve: "P-256",
+    },
+    true,
+    ["sign", "verify"]
+  );
+}

libs/common/src/webauthn/services/fido2-authenticator.service.ts

@@ -123,7 +123,7 @@ export class Fido2AuthenticatorService implements Fido2AuthenticatorServiceAbstr
     const credentialId = params.requireResidentKey ? cipher.id : cipher.fido2Key.nonDiscoverableId;
     const authData = await generateAuthData({
       rpId: params.rpEntity.id,
-      credentialId,
+      credentialId: Utils.guidToRawFormat(credentialId),
       counter: cipher.fido2Key.counter,
       userPresence: true,
       userVerification: false,
@@ -201,7 +201,7 @@ export class Fido2AuthenticatorService implements Fido2AuthenticatorServiceAbstr
 
       const authenticatorData = await generateAuthData({
         rpId: selectedCipher.fido2Key.rpId,
-        credentialId: selectedCredentialId,
+        credentialId: Utils.guidToRawFormat(selectedCredentialId),
         counter: selectedCipher.fido2Key.counter,
         userPresence: true,
         userVerification: false,
@@ -209,7 +209,7 @@ export class Fido2AuthenticatorService implements Fido2AuthenticatorServiceAbstr
 
       const signature = await generateSignature({
         authData: authenticatorData,
-        clientData: params.hash,
+        clientDataHash: params.hash,
         privateKey: await getPrivateKeyFromCipher(selectedCipher),
       });
 
@@ -340,7 +340,7 @@ async function getPrivateKeyFromCipher(cipher: CipherView): Promise<CryptoKey> {
 
 interface AuthDataParams {
   rpId: string;
-  credentialId: string;
+  credentialId: BufferSource;
   userPresence: boolean;
   userVerification: boolean;
   counter: number;
@@ -380,7 +380,7 @@ async function generateAuthData(params: AuthDataParams) {
     attestedCredentialData.push(...AAGUID);
 
     // credentialIdLength (2 bytes) and credential Id
-    const rawId = Utils.guidToRawFormat(params.credentialId);
+    const rawId = Fido2Utils.bufferSourceToUint8Array(params.credentialId);
     const credentialIdLength = [(rawId.length - (rawId.length & 0xff)) / 256, rawId.length & 0xff];
     attestedCredentialData.push(...credentialIdLength);
     attestedCredentialData.push(...rawId);
@@ -408,14 +408,15 @@ async function generateAuthData(params: AuthDataParams) {
 
 interface SignatureParams {
   authData: Uint8Array;
-  clientData: BufferSource;
+  clientDataHash: BufferSource;
   privateKey: CryptoKey;
 }
 
 async function generateSignature(params: SignatureParams) {
-  const clientData = Fido2Utils.bufferSourceToUint8Array(params.clientData);
-  const clientDataHash = await crypto.subtle.digest({ name: "SHA-256" }, clientData);
-  const sigBase = new Uint8Array([...params.authData, ...new Uint8Array(clientDataHash)]);
+  const sigBase = new Uint8Array([
+    ...params.authData,
+    ...Fido2Utils.bufferSourceToUint8Array(params.clientDataHash),
+  ]);
   const p1336_signature = new Uint8Array(
     await crypto.subtle.sign(
       {

libs/common/src/webauthn/services/fido2-client.service.ts

@@ -159,7 +159,7 @@ export class Fido2ClientService implements Fido2ClientServiceAbstraction {
     }
 
     const collectedClientData = {
-      type: "webauthn.create",
+      type: "webauthn.get",
       challenge: params.challenge,
       origin: params.origin,
       crossOrigin: !params.sameOriginWithAncestors,