Webauthn Framework
v4.0
v4.0
  • The project
    • Introduction
    • Web Browser Support
    • Installation
    • Contributing
  • Webauthn In A Nutshell
    • Authenticators
    • Ceremonies
    • Metadata Statement
    • User Verification
    • Extensions
    • Token Binding
  • Prerequisites
    • The Relying Party
    • Credential Source Repository
    • User Entity
    • Javascript
  • Pure PHP
    • Webauthn Server
    • Register Authenticators
    • Authenticate Your Users
    • Advanced Behaviours
      • Debugging
      • User Verification
      • Authenticator Selection Criteria
      • Attestation and Metadata Statement
      • Authentication without username
      • Extensions
      • Authenticator Counter
      • Dealing with “localhost”
  • Symfony Bundle
    • Bundle Installation
    • Credential Source Repository
    • User Entity Repository
    • Firewall
    • Configuration References
    • Advanced Behaviors
      • Register Additional Authenticators
      • Debugging
      • User Verification
      • Attestation and Metadata Statement
      • Authenticator Selection Criteria
      • Authentication without username
      • Extensions
      • Token Binding
      • Authenticator Counter
      • Dealing with “localhost”
  • Migration
    • From v3.x to v4.0
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  1. Webauthn In A Nutshell

Token Binding

PreviousExtensionsNextThe Relying Party

Last updated 3 years ago

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Browsers may support the Token Binding protocol (see ). This protocol defines a way to bind a token (the Responses in the Webauthn context) to the underlying TLS layer.

When receiving a Webauthn Response, the property tokenBinding in the Webauthn\CollectedClientData object has one of the following values:

  • null: the token binding is not supported by the browser

  • "supported": the browser supports token binding, but no negotiation was performed during the communication

  • "present": the browser supports token binding, and it is present in the response. The token binding ID is provided.

This feature is not yet implemented in the library, but you can decide how the library will react in case of the presence of the token binding ID.

The library provides two concrete classes for the moment:

  • Webauthn\TokenBinding\IgnoreTokenBindingHandler: the library will ignore the token binding (recommended),

  • Webauthn\TokenBinding\TokenBindingNotSupportedHandler: the library will throw an exception if the token binding is present.

You can change this behavior by creating your own implementation. The handler must implement the interface Webauthn\TokenBinding\TokenBindingHandler.

RFC 8471