schemas/middleware/auth0.go

package middleware

import (
	"context"
	"fmt"
	"log"
	"net/url"

	jwtmiddleware "github.com/auth0/go-jwt-middleware/v3"
	"github.com/auth0/go-jwt-middleware/v3/jwks"
	"github.com/auth0/go-jwt-middleware/v3/validator"
)

// CustomClaims contains custom claims from the JWT token.
type CustomClaims struct {
	Roles []string `json:"https://unbound.se/roles"`
}

// Validate implements the validator.CustomClaims interface.
func (c CustomClaims) Validate(_ context.Context) error {
	return nil
}

type Auth0 struct {
	domain   string
	audience string
}

func NewAuth0(audience, domain string, _ bool) *Auth0 {
	return &Auth0{
		domain:   domain,
		audience: audience,
	}
}

type Response struct {
	Message string `json:"message"`
}

func (a *Auth0) Middleware() *jwtmiddleware.JWTMiddleware {
	issuer := fmt.Sprintf("https://%s/", a.domain)

	issuerURL, err := url.Parse(issuer)
	if err != nil {
		log.Fatalf("failed to parse issuer URL: %v", err)
	}

	provider, err := jwks.NewCachingProvider(jwks.WithIssuerURL(issuerURL))
	if err != nil {
		log.Fatalf("failed to create JWKS provider: %v", err)
	}

	jwtValidator, err := validator.New(
		validator.WithKeyFunc(provider.KeyFunc),
		validator.WithAlgorithm(validator.RS256),
		validator.WithIssuer(issuer),
		validator.WithAudience(a.audience),
		validator.WithCustomClaims(func() validator.CustomClaims {
			return &CustomClaims{}
		}),
	)
	if err != nil {
		log.Fatalf("failed to create JWT validator: %v", err)
	}

	jwtMiddleware, err := jwtmiddleware.New(
		jwtmiddleware.WithValidator(jwtValidator),
		jwtmiddleware.WithCredentialsOptional(true),
	)
	if err != nil {
		log.Fatalf("failed to create JWT middleware: %v", err)
	}

	return jwtMiddleware
}

func ClaimsFromContext(ctx context.Context) *validator.ValidatedClaims {
	claims, err := jwtmiddleware.GetClaims[*validator.ValidatedClaims](ctx)
	if err != nil {
		return nil
	}
	return claims
}