feat(auth): automatically generate anonymous user session

ref arcad/edge-menu#86

pkg/module/auth/jwt/jwt.go

@@ -0,0 +1,35 @@
+package jwt
+
+import (
+	"time"
+
+	"github.com/lestrrat-go/jwx/v2/jwa"
+	"github.com/lestrrat-go/jwx/v2/jwk"
+	"github.com/lestrrat-go/jwx/v2/jwt"
+	"github.com/pkg/errors"
+)
+
+func GenerateSignedToken(algo jwa.KeyAlgorithm, key jwk.Key, claims map[string]any) ([]byte, error) {
+	token := jwt.New()
+
+	if err := token.Set(jwt.NotBeforeKey, time.Now()); err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	for key, value := range claims {
+		if err := token.Set(key, value); err != nil {
+			return nil, errors.Wrapf(err, "could not set claim '%s' with value '%v'", key, value)
+		}
+	}
+
+	if err := token.Set(jwk.AlgorithmKey, jwa.HS256); err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	rawToken, err := jwt.Sign(token, jwt.WithKey(algo, key))
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	return rawToken, nil
+}