feat: sanitize input before passing it around

helpers.go

@@ -0,0 +1,113 @@
+package main
+
+import (
+	"archive/zip"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+func DownloadCache() error {
+	resp, err := http.Get("https://thunderstore.io/api/v1/package/")
+	if err != nil {
+		return fmt.Errorf("couldn't download payload: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if err := os.MkdirAll(TMPDIR, os.ModePerm); err != nil {
+		return fmt.Errorf("couldn't create tmpdir: %w", err)
+	}
+	out, err := os.Create(PAYLOAD)
+	if err != nil {
+		return fmt.Errorf("couldn't create file: %w", err)
+	}
+	defer out.Close()
+
+	if _, err := io.Copy(out, resp.Body); err != nil {
+		return fmt.Errorf("couldn't write to file: %w", err)
+	}
+
+	return nil
+}
+
+func DownloadBepinex() error {
+	tmpPath := TMPDIR + "/bepinex.zip"
+	resp, err := http.Get("https://github.com/BepInEx/BepInEx/releases/download/v5.4.23.2/BepInEx_win_x64_5.4.23.2.zip")
+	if err != nil {
+		return fmt.Errorf("could not download bepinex: %w", err)
+	}
+	defer resp.Body.Close()
+
+	out, err := os.Create(tmpPath)
+	if err != nil {
+		return fmt.Errorf("could not create file: %w", err)
+	}
+	defer out.Close()
+
+	_, err = io.Copy(out, resp.Body)
+	if err != nil {
+		return fmt.Errorf("could not save file: %w", err)
+	}
+
+	err = unzip(tmpPath, GAME_PATH)
+	if err != nil {
+		return fmt.Errorf("could not extract BepInEx: %w", err)
+	}
+
+	return nil
+}
+
+func unzip(src, dest string) error {
+	r, err := zip.OpenReader(src)
+	if err != nil {
+		return err
+	}
+	defer r.Close()
+
+	for _, f := range r.File {
+		fpath := filepath.Join(dest, f.Name)
+
+		if f.FileInfo().IsDir() {
+			os.MkdirAll(fpath, os.ModePerm)
+			continue
+		}
+
+		if err := os.MkdirAll(filepath.Dir(fpath), os.ModePerm); err != nil {
+			return err
+		}
+
+		outFile, err := os.OpenFile(fpath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, f.Mode())
+		if err != nil {
+			return err
+		}
+
+		rc, err := f.Open()
+		if err != nil {
+			outFile.Close()
+			return err
+		}
+
+		_, err = io.Copy(outFile, rc)
+
+		outFile.Close()
+		rc.Close()
+
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func SanitizeInput(input *string) error {
+	if *input == "" {
+		return fmt.Errorf("%s is not set", *input)
+	}
+	if strings.HasSuffix(*input, "/") {
+		*input = strings.TrimSuffix(*input, "/")
+	}
+	return nil
+}

spire.go

@@ -2,9 +2,7 @@ package main
 
 import (
 	"fmt"
-	"io"
 	"log"
-	"net/http"
 	"os"
 	"time"
 )
@@ -14,18 +12,25 @@ const (
 	PAYLOAD = TMPDIR + "/payload.json"
 )
 
+var GAME_PATH = os.Getenv("GAME_PATH")
+
 func main() {
-	get_cache()
+	getCache()
+	if err := SanitizeInput(&GAME_PATH); err != nil {
+		log.Fatal("GAME_PATH is not set")
+	}
+	installBepinex()
 }
 
-func get_cache() error {
+func getCache() error {
 	info, err := os.Stat(PAYLOAD)
 
 	if err != nil {
 		fmt.Println("payload isn't accessible, requesting")
-		download_cache()
+		DownloadCache()
 	} else if !(info.ModTime().After(time.Now().Add(-2 * time.Hour))) {
-		download_cache()
+		// download again if payload is older than 2 hours
+		DownloadCache()
 	} else {
 		fmt.Println("payload was updated recently, won't update")
 	}
@@ -33,29 +38,13 @@ func get_cache() error {
 	return nil
 }
 
-func download_cache() error {
+func installBepinex() {
-	resp, err := http.Get("https://thunderstore.io/api/v1/package/")
+	_, err := os.Stat(GAME_PATH + "/BepInEx")
+
 	if err != nil {
-		log.Fatal("couldn't download thunderstore payload")
+		// install bepinex
-		return err
+		DownloadBepinex()
+	} else {
+		fmt.Println("bepinex already installed")
 	}
-	defer resp.Body.Close()
-
-	if err := os.MkdirAll(TMPDIR, os.ModePerm); err != nil {
-		log.Fatal("couldn't create tmpdir")
-		return err
-	}
-	out, err := os.Create(PAYLOAD)
-	if err != nil {
-		log.Fatal("couldn't create payload file")
-		return err
-	}
-	defer out.Close()
-
-	if _, err := io.Copy(out, resp.Body); err != nil {
-		log.Fatal("couldn't write to payload file")
-		return err
-	}
-
-	return nil
 }