kaspersky.go

package main

import (
	"bytes"
	"flag"
	"fmt"
	"log"
	"net/http"
	"os/exec"
	"regexp"
)

type ScanResult struct {
	isFileSafe bool
}

func scanFile(settings Settings, filePath string) (ScanResult, bool) {
	var command *exec.Cmd

	if settings.useSudo {
		command = exec.Command("sudo", "-n", settings.kasperskyPath, "--scan-file", filePath)
	} else {
		command = exec.Command(settings.kasperskyPath, fmt.Sprintf("--scan-file %s", filePath))
	}

	var stdout bytes.Buffer
	var stderr bytes.Buffer
	command.Stdout = &stdout
	command.Stderr = &stderr
	err := command.Run()

	if err != nil {
		log.Printf("[ERROR] Scanning file `%s` failed: %s", filePath, stderr.String())
		return ScanResult{}, false
	} else {
		safeFileRegexp := regexp.MustCompile("Threats found:\\s+0")
		var isFileSafe = safeFileRegexp.MatchString(stdout.String())
		log.Printf("[INFO] Scanning file: %s, safe: %t", filePath, isFileSafe)
		return ScanResult{isFileSafe: isFileSafe}, true
	}
}

func fastScanHandler(settings Settings) http.HandlerFunc {
	return func(writer http.ResponseWriter, request *http.Request) {
		writer.Header().Set("Content-Type", "application/json; charset=utf-8") // normal header

		filePath := request.URL.Query().Get("file_path")
		if filePath != "" {
			result, ok := scanFile(settings, filePath)
			if ok {
				json := fmt.Sprintf("{ \"safe\": %t}", result.isFileSafe)
				fmt.Fprintf(writer, json)
			} else {
				writer.WriteHeader(http.StatusInternalServerError)
				fmt.Fprintf(writer, "{ \"error\": \"something went wrong while scanning the file, see logs for details\"}")
			}
		} else {
			writer.WriteHeader(http.StatusBadRequest)
			fmt.Fprintf(writer, "{ \"error\": \"missing `file_path` parameter\"}")
		}
	}
}

type Settings struct {
	kasperskyPath string
	useSudo       bool
}

const defaultBinding = "127.0.0.1:8080"
const defaultKasperskyPath = "/opt/kaspersky/kav4fs/bin/kav4fs-control"

func main() {
	bind := flag.String("bind", defaultBinding, "bind address - defaults to '127.0.0.1:8080'")
	kasperskyPath := flag.String("kaspersky-path", defaultKasperskyPath, "full path to kav4fs-control binary")
	useSudo := flag.Bool("sudo", false, "use sudo or not")
	flag.Parse()

	settings := Settings{kasperskyPath: *kasperskyPath, useSudo: *useSudo}

	log.Printf("[INFO] Starting HTTP server on %s", *bind)

	http.HandleFunc("/fast_scan", fastScanHandler(settings))
	err := http.ListenAndServe(*bind, nil)
	log.Printf("[ERROR] %s", err)
}