From 42281a6577bad9acb9bb8b94978f873caa909f97 Mon Sep 17 00:00:00 2001
From: Alexander Zobnin <alexanderzobnin@gmail.com>
Date: Tue, 27 Dec 2022 13:04:46 +0100
Subject: [PATCH] Support authentication for zabbix < 5.4, #1544

---
 pkg/zabbixapi/zabbix_api.go | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/pkg/zabbixapi/zabbix_api.go b/pkg/zabbixapi/zabbix_api.go
index 52c5d05..dc6490d 100644
--- a/pkg/zabbixapi/zabbix_api.go
+++ b/pkg/zabbixapi/zabbix_api.go
@@ -9,6 +9,7 @@ import (
 	"io/ioutil"
 	"net/http"
 	"net/url"
+	"strings"
 
 	"github.com/alexanderzobnin/grafana-zabbix/pkg/metrics"
 	"github.com/bitly/go-simplejson"
@@ -135,10 +136,31 @@ func (api *ZabbixAPI) Login(ctx context.Context, username string, password strin
 	return auth.MustString(), nil
 }
 
+// Login methid for Zabbix prior to 5.4
+func (api *ZabbixAPI) LoginDeprecated(ctx context.Context, username string, password string) (string, error) {
+	params := ZabbixAPIParams{
+		"user":     username,
+		"password": password,
+	}
+
+	auth, err := api.request(ctx, "user.login", params, "")
+	if err != nil {
+		return "", err
+	}
+
+	return auth.MustString(), nil
+}
+
 // Authenticate performs API authentication and sets authentication token.
 func (api *ZabbixAPI) Authenticate(ctx context.Context, username string, password string) error {
 	auth, err := api.Login(ctx, username, password)
-	if err != nil {
+	if isDeprecatedUserParamError(err) {
+		api.logger.Debug("user.login method error, switching to deprecated user parameter", "error", err)
+		auth, err = api.LoginDeprecated(ctx, username, password)
+		if err != nil {
+			return err
+		}
+	} else if err != nil {
 		return err
 	}
 
@@ -146,6 +168,15 @@ func (api *ZabbixAPI) Authenticate(ctx context.Context, username string, passwor
 	return nil
 }
 
+func isDeprecatedUserParamError(err error) bool {
+	if err == nil {
+		return false
+	} else if strings.Contains(err.Error(), `unexpected parameter "user`) {
+		return true
+	}
+	return false
+}
+
 func handleAPIResult(response []byte) (*simplejson.Json, error) {
 	jsonResp, err := simplejson.NewJson([]byte(response))
 	if err != nil {