1 files changed, 65 insertions, 0 deletions
diff --git a/packages/browser/src/methods/startRegistration.ts b/packages/browser/src/methods/startRegistration.ts
new file mode 100644
index 0000000..eec07c5
--- /dev/null
+++ b/packages/browser/src/methods/startRegistration.ts
@@ -0,0 +1,65 @@
+import {
+  PublicKeyCredentialCreationOptionsJSON,
+  RegistrationCredential,
+  RegistrationCredentialJSON,
+} from '@simplewebauthn/typescript-types';
+
+import utf8StringToBuffer from '../helpers/utf8StringToBuffer';
+import bufferToBase64URLString from '../helpers/bufferToBase64URLString';
+import base64URLStringToBuffer from '../helpers/base64URLStringToBuffer';
+import { browserSupportsWebauthn } from '../helpers/browserSupportsWebauthn';
+import toPublicKeyCredentialDescriptor from '../helpers/toPublicKeyCredentialDescriptor';
+
+/**
+ * Begin authenticator "registration" via WebAuthn attestation
+ *
+ * @param creationOptionsJSON Output from @simplewebauthn/server's generateRegistrationOptions(...)
+ */
+export default async function startRegistration(
+  creationOptionsJSON: PublicKeyCredentialCreationOptionsJSON,
+): Promise<RegistrationCredentialJSON> {
+  if (!browserSupportsWebauthn()) {
+    throw new Error('WebAuthn is not supported in this browser');
+  }
+
+  // We need to convert some values to Uint8Arrays before passing the credentials to the navigator
+  const publicKey: PublicKeyCredentialCreationOptions = {
+    ...creationOptionsJSON,
+    challenge: base64URLStringToBuffer(creationOptionsJSON.challenge),
+    user: {
+      ...creationOptionsJSON.user,
+      id: utf8StringToBuffer(creationOptionsJSON.user.id),
+    },
+    excludeCredentials: creationOptionsJSON.excludeCredentials.map(toPublicKeyCredentialDescriptor),
+  };
+
+  // Wait for the user to complete attestation
+  const credential = (await navigator.credentials.create({ publicKey })) as RegistrationCredential;
+
+  if (!credential) {
+    throw new Error('Registration was not completed');
+  }
+
+  const { id, rawId, response, type } = credential;
+
+  // Convert values to base64 to make it easier to send back to the server
+  const credentialJSON: RegistrationCredentialJSON = {
+    id,
+    rawId: bufferToBase64URLString(rawId),
+    response: {
+      attestationObject: bufferToBase64URLString(response.attestationObject),
+      clientDataJSON: bufferToBase64URLString(response.clientDataJSON),
+    },
+    type,
+    clientExtensionResults: credential.getClientExtensionResults(),
+  };
+
+  /**
+   * Include the authenticator's transports if the browser supports querying for them
+   */
+  if (typeof response.getTransports === 'function') {
+    credentialJSON.transports = response.getTransports();
+  }
+
+  return credentialJSON;
+}