improve error handling and style

auth/basic/README.md

@@ -1,4 +1,8 @@
-`package auth/basic` provides a Basic Authentication middleware [Mozilla article](https://developer.mozilla.org/en-US/docs/Web/HTTP/Authentication).
+This package provides a Basic Authentication middleware.
+
+It'll try to compare credentials from Authentication request header to a username/password pair in middleware constructor.
+
+More details about this type of authentication can be found in [Mozilla article](https://developer.mozilla.org/en-US/docs/Web/HTTP/Authentication).
 
 ## Usage
 
@@ -6,7 +10,7 @@
 import httptransport "github.com/go-kit/kit/transport/http"
 
 httptransport.NewServer(
-		endpoint.Chain(AuthMiddleware(cfg.auth.user, cfg.auth.password, "Example Realm"))(makeUppercaseEndpoint()),
+		AuthMiddleware(cfg.auth.user, cfg.auth.password, "Example Realm")(makeUppercaseEndpoint()),
 		decodeMappingsRequest,
 		httptransport.EncodeJSONResponse,
 		httptransport.ServerBefore(httptransport.PopulateRequestContext),

auth/basic/middleware.go

@@ -34,7 +34,8 @@ func (e AuthError) Headers() http.Header {
 	return http.Header{
 		"Content-Type":           []string{"text/plain; charset=utf-8"},
 		"X-Content-Type-Options": []string{"nosniff"},
-		"WWW-Authenticate":       []string{fmt.Sprintf(`Basic realm=%q`, e.Realm)}}
+		"WWW-Authenticate":       []string{fmt.Sprintf(`Basic realm=%q`, e.Realm)},
+	}
 }
 
 // parseBasicAuth parses an HTTP Basic Authentication string.
@@ -69,7 +70,11 @@ func AuthMiddleware(requiredUser, requiredPassword, realm string) endpoint.Middl
 
 	return func(next endpoint.Endpoint) endpoint.Endpoint {
 		return func(ctx context.Context, request interface{}) (interface{}, error) {
-			auth := ctx.Value(httptransport.ContextKeyRequestAuthorization).(string)
+			auth, ok := ctx.Value(httptransport.ContextKeyRequestAuthorization).(string)
+			if !ok {
+				return nil, AuthError{realm}
+			}
+
 			givenUser, givenPassword, ok := parseBasicAuth(auth)
 			if !ok {
 				return nil, AuthError{realm}

auth/basic/middleware_test.go

@@ -20,9 +20,11 @@ func TestWithBasicAuth(t *testing.T) {
 	}
 	tests := []struct {
 		name       string
-		authHeader string
+		authHeader interface{}
 		want       want
 	}{
+		{"Isn't valid with nil header", nil, want{nil, AuthError{realm}}},
+		{"Isn't valid with non-string header", 42, want{nil, AuthError{realm}}},
 		{"Isn't valid without authHeader", "", want{nil, AuthError{realm}}},
 		{"Isn't valid for wrong user", makeAuthString("wrong-user", requiredPassword), want{nil, AuthError{realm}}},
 		{"Isn't valid for wrong password", makeAuthString(requiredUser, "wrong-password"), want{nil, AuthError{realm}}},