webauthn-protocol

Audience: integrators and adapters that need strict WebAuthn binary protocol interpretation without selecting a JSON or CBOR object codec.

What it provides

• Parsing of authenticator-data bytes into typed WebAuthn model values
• Structural extraction of authData from a CBOR attestation object
• Validation errors expressed through the neutral webauthn-model result types

When to use

Use this module at the boundary between untrusted raw credential bytes and clean WebAuthn protocol models. It depends only on webauthn-model and webauthn-cbor-core; it does not require kotlinx.serialization.

How to use

fun parseAuthenticatorData(bytes: ByteArray): ValidationResult<ParsedAuthenticatorData> {
    return WebAuthnProtocolParser.parseAuthenticatorData(bytes)
}

For registration responses, call extractAuthenticatorData on the raw attestation object before parsing the returned immutable Base64UrlBytes value. The caller remains responsible for ceremony policy and attestation verification.

How it fits in the system

flowchart LR
    PROTOCOL["webauthn-protocol"] --> CBOR["webauthn-cbor-core"]
    PROTOCOL --> MODEL["webauthn-model"]
    SERIALIZATION["webauthn-json-kotlinx"] --> PROTOCOL

Arrows point from a consuming module to its direct dependency. JSON implementations may use the protocol parser, while the parser itself remains independent of any serialization implementation.

Status

Beta, public protocol interpretation module.