package middleware import ( "encoding/base64" "strconv" "github.com/labstack/echo" ) type ( // BasicAuthConfig defines the config for BasicAuth middleware. BasicAuthConfig struct { // Skipper defines a function to skip middleware. Skipper Skipper // Validator is a function to validate BasicAuth credentials. // Required. Validator BasicAuthValidator // Realm is a string to define realm attribute of BasicAuth. // Default value "Restricted". Realm string } // BasicAuthValidator defines a function to validate BasicAuth credentials. BasicAuthValidator func(string, string, echo.Context) (bool, error) ) const ( basic = "Basic" defaultRealm = "Restricted" ) var ( // DefaultBasicAuthConfig is the default BasicAuth middleware config. DefaultBasicAuthConfig = BasicAuthConfig{ Skipper: DefaultSkipper, Realm: defaultRealm, } ) // BasicAuth returns an BasicAuth middleware. // // For valid credentials it calls the next handler. // For missing or invalid credentials, it sends "401 - Unauthorized" response. func BasicAuth(fn BasicAuthValidator) echo.MiddlewareFunc { c := DefaultBasicAuthConfig c.Validator = fn return BasicAuthWithConfig(c) } // BasicAuthWithConfig returns an BasicAuth middleware with config. // See `BasicAuth()`. func BasicAuthWithConfig(config BasicAuthConfig) echo.MiddlewareFunc { // Defaults if config.Validator == nil { panic("basic-auth middleware requires a validator function") } if config.Skipper == nil { config.Skipper = DefaultBasicAuthConfig.Skipper } if config.Realm == "" { config.Realm = defaultRealm } return func(next echo.HandlerFunc) echo.HandlerFunc { return func(c echo.Context) error { if config.Skipper(c) { return next(c) } auth := c.Request().Header.Get(echo.HeaderAuthorization) l := len(basic) if len(auth) > l+1 && auth[:l] == basic { b, err := base64.StdEncoding.DecodeString(auth[l+1:]) if err != nil { return err } cred := string(b) for i := 0; i < len(cred); i++ { if cred[i] == ':' { // Verify credentials valid, err := config.Validator(cred[:i], cred[i+1:], c) if err != nil { return err } else if valid { return next(c) } } } } realm := "" if config.Realm == defaultRealm { realm = defaultRealm } else { realm = strconv.Quote(config.Realm) } // Need to return `401` for browsers to pop-up login box. c.Response().Header().Set(echo.HeaderWWWAuthenticate, basic+" realm="+realm) return echo.ErrUnauthorized } } }