Add new generateUserHandle helper

1 files changed, 16 insertions, 0 deletions

diff --git a/packages/server/src/helpers/generateUserHandle.ts b/packages/server/src/helpers/generateUserHandle.ts
new file mode 100644
index 0000000..be3f838
--- /dev/null
+++ b/packages/server/src/helpers/generateUserHandle.ts
@@ -0,0 +1,16 @@
+import crypto from 'crypto';
+
+/**
+ * Generate a suitably random value to be used as a user handle when creating a credential
+ */
+export default function generateUserHandle(): Buffer {
+  /**
+   * As per WebAuthn spec:
+   *
+   * "A user handle is an opaque byte sequence with a maximum size of 64 bytes, and is not meant to
+   * be displayed to the user."
+   *
+   * See https://w3c.github.io/webauthn/#user-handle
+   */
+  return crypto.randomBytes(64);
+}