This library is meant to handle Web Authentication for Go apps that wish to implement a passwordless solution for users. This library conforms as much as possible to the guidelines and implementation procedures outlined by the document.
This library is a hard fork of github.com/duo-labs/webauthn and is the natural successor to that library.
See the migration guide for more information about how to migrate and the differences between the libraries.
It is distributed under the same 3-Clause BSD license as the original fork, with the only amendment being the additional 3-Clause BSD license attributing license rights to this repository.
This library is still version 0, as per Semantic Versioning 2.0 rules there may be breaking changes without warning. While we strive to avoid such changes and strive to notify users they may be unavoidable.
go get github.com/go-webauthn/webauthn and initialize it in your application with basic configuration values.
Make sure your user model is able to handle the interface functions laid out in webauthn/user.go. This means also
supporting the storage and retrieval of the credential and authenticator structs in webauthn/credential.go and
webauthn/authenticator.go, respectively.
The following examples show some basic use cases of the library. For consistency sake the following variables are used to denote specific things:
- Variable
w: thewebauthn.WebAuthninstance you initialize elsewhere in your code - Variable
datastore: the pseudocode backend service that stores your webauthn session data and users such as PostgreSQL - Variable
session: the webauthn.SessionData object - Variable
user: your webauthn.User implementation
We try to avoid using specific external libraries (excluding stdlib) where possible, and you'll need to adapt these examples with this in mind.
package example
import (
"fmt"
"time"
"github.com/go-webauthn/webauthn/webauthn"
)
var (
w *webauthn.WebAuthn
err error
)
// Your initialization function
func main() {
wconfig := &webauthn.Config{
RPDisplayName: "Go Webauthn", // Display Name for your site
RPID: "go-webauthn.local", // Generally the FQDN for your site
RPOrigins: []string{"https://login.go-webauthn.local"}, // The origin URLs allowed for WebAuthn requests
}
if w, err = webauthn.New(wconfig); err != nil {
fmt.Println(err)
}
}package example
func BeginRegistration(w http.ResponseWriter, r *http.Request) {
user := datastore.GetUser() // Find or create the new user
options, session, err := web.BeginRegistration(user)
// handle errors if present
// store the sessionData values
JSONResponse(w, options, http.StatusOK) // return the options generated
// options.publicKey contain our registration options
}
func FinishRegistration(w http.ResponseWriter, r *http.Request) {
response, err := protocol.ParseCredentialCreationResponseBody(r.Body)
if err != nil {
// Handle Error and return.
return
}
user := datastore.GetUser() // Get the user
// Get the session data stored from the function above
session := datastore.GetSession()
credential, err := w.CreateCredential(user, session, response)
if err != nil {
// Handle Error and return.
return
}
// If creation was successful, store the credential object
JSONResponse(w, "Registration Success", http.StatusOK) // Handle next steps
// Pseudocode to add the user credential.
user.AddCredential(credential)
datastore.SaveUser(user)
}package example
func BeginLogin(w http.ResponseWriter, r *http.Request) {
user := datastore.GetUser() // Find the user
options, session, err := w.BeginLogin(user)
if err != nil {
// Handle Error and return.
return
}
// store the session values
datastore.SaveSession(session)
JSONResponse(w, options, http.StatusOK) // return the options generated
// options.publicKey contain our registration options
}
func FinishLogin(w http.ResponseWriter, r *http.Request) {
response, err := protocol.ParseCredentialRequestResponseBody(r.Body)
if err != nil {
// Handle Error and return.
return
}
user := datastore.GetUser() // Get the user
// Get the session data stored from the function above
session := datastore.GetSession()
credential, err := w.ValidateLogin(user, session, response)
if err != nil {
// Handle Error and return.
return
}
// If login was successful, handle next steps
JSONResponse(w, "Login Success", http.StatusOK)
}You can modify the default credential creation options for registration and login by providing optional structs to the
BeginRegistration and BeginLogin functions.
You can modify the registration options in the following ways:
package example
import (
"github.com/go-webauthn/webauthn/protocol"
"github.com/go-webauthn/webauthn/webauthn"
)
var w webauthn.WebAuthn // init this in your init function
func beginRegistration() {
// Updating the AuthenticatorSelection options.
// See the struct declarations for values
authSelect := protocol.AuthenticatorSelection{
AuthenticatorAttachment: protocol.AuthenticatorAttachment("platform"),
RequireResidentKey: protocol.ResidentKeyNotRequired(),
UserVerification: protocol.VerificationRequired,
}
// Updating the ConveyencePreference options.
// See the struct declarations for values
conveyancePref := protocol.PreferNoAttestation
user := datastore.GetUser() // Get the user
opts, session, err := w.BeginRegistration(user, webauthn.WithAuthenticatorSelection(authSelect), webauthn.WithConveyancePreference(conveyancePref))
// Handle next steps
}You can modify the login options to allow only certain credentials:
package example
import (
"github.com/go-webauthn/webauthn/protocol"
"github.com/go-webauthn/webauthn/webauthn"
)
var w webauthn.WebAuthn // init this in your init function
func beginLogin() {
// Updating the AuthenticatorSelection options.
// See the struct declarations for values
allowList := make([]protocol.CredentialDescriptor, 1)
allowList[0] = protocol.CredentialDescriptor{
CredentialID: credentialToAllowID,
Type: protocol.CredentialType("public-key"),
}
user := datastore.GetUser() // Get the user
opts, session, err := w.BeginLogin(user, webauthn.WithAllowedCredentials(allowList))
// Handle next steps
}The library by default does not enforce timeouts. However the default timeouts sent to the browser are taken from the specification. You can override both of these behaviours however.
package example
import (
"fmt"
"time"
"github.com/go-webauthn/webauthn/protocol"
"github.com/go-webauthn/webauthn/webauthn"
)
func main() {
wconfig := &webauthn.Config{
RPDisplayName: "Go Webauthn", // Display Name for your site
RPID: "go-webauthn.local", // Generally the FQDN for your site
RPOrigins: []string{"https://login.go-webauthn.local"}, // The origin URLs allowed for WebAuthn requests
Timeouts: webauthn.TimeoutsConfig{
Login: webauthn.TimeoutConfig{
Enforce: true, // Require the response from the client comes before the end of the timeout.
Timeout: time.Second * 60, // Standard timeout for login sessions.
TimeoutUVD: time.Second * 60, // Timeout for login sessions which have user verification set to discouraged.
},
Registration: webauthn.TimeoutConfig{
Enforce: true, // Require the response from the client comes before the end of the timeout.
Timeout: time.Second * 60, // Standard timeout for registration sessions.
TimeoutUVD: time.Second * 60, // Timeout for login sessions which have user verification set to discouraged.
},
},
}
w, err := webauthn.New(wconfig)
if err != nil {
fmt.Println(err)
}
}We graciously acknowledge the original authors of this library github.com/duo-labs/webauthn for their amazing implementation. Without their amazing work this library could not exist.