authenticate
Authenticates with an existing WebAuthn credential (passkey assertion).
Triggers the platform's credential assertion flow, prompting the user to authenticate with their passkey using biometric authentication or a security key.
Flow:
Platform shows biometric/security key prompt
User authenticates with fingerprint, face, or security key
Platform signs the challenge with the private key
Returns signature and authenticator data
IMPORTANT: The challenge parameter MUST be used as-is in the WebAuthn authentication request. It is the authorization payload hash that must be signed to authorize the transaction.
Return
WebAuthnAuthenticationResult with signature and attestation data
Parameters
The challenge bytes to sign (authorization payload hash, 32 bytes)
Optional list of credential descriptors with transport hints. Constrains which passkey the authenticator uses and indicates how the client can reach the authenticator. When null, discoverable credential selection is used (the user picks which passkey to use). Including transport hints (e.g., "hybrid") enables cross-device authentication flows such as QR code scanning.
Throws
if authentication fails or user cancels