add output verification

README.md

@@ -12,6 +12,7 @@ arguments:
   -d, --device string   target device
   -f, --force           override safety features
   -i, --input string    input file
+  -n, --no-hash         disable hash verification
 ```
 
 If no image or device is specified, etcher will enter interactive mode and prompt for the missing parameters.

main.go

@@ -6,6 +6,9 @@ import (
 	"time"
 	"log"
 	"strings"
+	"runtime"
+	"strconv"
+	"crypto/sha256"
 	"github.com/schollz/progressbar/v3"
 	"github.com/fatih/color"
 	"github.com/briandowns/spinner"
@@ -16,11 +19,13 @@ import (
 var device string
 var input string
 var force bool
+var disable_hash bool
 
 func init() {
 	flag.StringVarP(&device, "device", "d", "", "target device")
 	flag.StringVarP(&input, "input", "i", "", "input file")
 	flag.BoolVarP(&force, "force", "f", false, "override safety features")
+	flag.BoolVarP(&disable_hash, "no-hash", "n", false, "disable hash verification")
 	flag.Parse()
 }
 
@@ -45,6 +50,7 @@ func GetPath() string {
 }
 
 func GetDest() string {
+	PrintAvail()
 	dest, err := ac.Read("[ " + color.YellowString("i") + " ]  Please input destination: ")
 	if err != nil {
 		log.Fatal(err)
@@ -85,24 +91,42 @@ func WriteImage(image *os.File, target *os.File, size int64) (int64, error) {
 	return written, err
 }
 
-func Sync(image *os.File, target *os.File) error {
+func PrintAvail() {
-	err := image.Sync()
+	if runtime.GOOS == "linux" {
-	if err != nil {
+		block, _ := os.ReadDir("/sys/block")
-		return err
+		if len(block) == 0 {
+			return
+		}
+		var targets []string
+		for _, device := range block {
+			if strings.HasPrefix(device.Name(), "sd") {
+				targets = append(targets, device.Name())
+			}
+			if strings.HasPrefix(device.Name(), "nvme") {
+				targets = append(targets, device.Name())
+			}
+			if strings.HasPrefix(device.Name(), "vd") {
+				targets = append(targets, device.Name())
+			}
+		}
+		fmt.Println("Available devices:")
+		for _, target := range targets {
+			sizefile, _ := os.Open("/sys/block/" + target + "/size")
+			sizeread, _ := io.ReadAll(sizefile)
+			_ = sizefile.Close()
+			sizestring := strings.ReplaceAll(string(sizeread), "\n", "")
+			size, _ := strconv.Atoi(sizestring)
+			size = size * 512
+			size = size / 1024 / 1024 / 1024
+
+			fmt.Print("     * ", "/dev/" + target)
+			if size > 0 {
+				fmt.Print(" [", size, "GB]\n")
+			} else {
+				fmt.Println("")
+			}
+		}
 	}
-	err = target.Sync()
-	if err != nil {
-		return err
-	}
-	err = image.Close()
-	if err != nil {
-		return err
-	}
-	err = target.Close()
-	if err != nil {
-		return err
-	}
-	return nil
 }
 
 func main() {
@@ -142,18 +166,11 @@ func main() {
 		s.Stop()
 		fmt.Println("\r[", color.RedString("✘"), "]  Getting file details                     ")
 		log.Fatal(err)
-	} else {
-		s.Stop()
-		fmt.Println("\r[", color.GreenString("✓"), "]  Getting file details                     ")
 	}
-
-	s.Prefix = "[ "
-	s.Suffix = " ]  Opening files"
-	s.Start()
 	image, err := os.Open(input)
 	if err != nil {
 		s.Stop()
-		fmt.Println("\r[", color.RedString("✘"), "]  Opening files                   ")
+		fmt.Println("\r[", color.RedString("✘"), "]  Getting file details                     ")
 		log.Fatal(err)
 	}
 	var inputsize int64
@@ -164,11 +181,12 @@ func main() {
 	} else {
 		inputsize, err = image.Seek(0, io.SeekEnd)
 		inputisblock = true
+		_, _ = image.Seek(0, 0)
 	}
 	target, err := os.OpenFile(device, os.O_RDWR, 0660)
 	if err != nil {
 		s.Stop()
-		fmt.Println("\r[", color.RedString("✘"), "]  Opening files                   ")
+		fmt.Println("\r[", color.RedString("✘"), "]  Getting file details                     ")
 		log.Fatal(err)
 	}
 	var targetsize int64
@@ -179,14 +197,26 @@ func main() {
 	} else {
 		targetsize, err = target.Seek(0, io.SeekEnd)
 		targetisblock = true
+		_, _ = target.Seek(0, 0)
+	}
+	prehash := sha256.New()
+	if ! (force || disable_hash) {
+		if err != nil {
+			s.Stop()
+			fmt.Println("\r[", color.RedString("✘"), "]  Getting file details                     ")
+			log.Fatal(err)
+		}
+
+		_, err = io.Copy(prehash, image)
+		_, _ = image.Seek(0, 0)
 	}
 	if err != nil {
 		s.Stop()
-		fmt.Println("\r[", color.RedString("✘"), "]  Opening files                   ")
+		fmt.Println("\r[", color.RedString("✘"), "]  Getting file details                     ")
 		log.Fatal(err)
 	} else {
 		s.Stop()
-		fmt.Println("\r[", color.GreenString("✓"), "]  Opening files                 ")
+		fmt.Println("\r[", color.GreenString("✓"), "]  Getting file details                     ")
 	}
 	inputmb := fmt.Sprint("[", inputsize / 1024 / 1024, "MB]")
 	devicemb := fmt.Sprint("[", targetsize / 1024 / 1024, "MB]")
@@ -204,18 +234,20 @@ func main() {
 	}
 	fmt.Println("[", color.BlueString("i"), "]  Input device/file: " + input, inputmb, inputblock)
 	fmt.Println("[", color.BlueString("i"), "]  Output device/file: " + device, devicemb, targetblock)
-	if statinput.Size() > statdevice.Size() {
+	if force == false {
-		fmt.Println("[", color.RedString("w"), "]", color.RedString(" Warning:"), "Input file seems to be bigger than the destination!")
+		if inputsize > targetsize {
+			fmt.Println("[", color.RedString("w"), "]", color.RedString(" Warning:"), "Input file seems to be bigger than the destination!")
+		}
+		fmt.Print(color.HiWhiteString("Do you want to continue? [y/N]: "))
+		var yesno string
+		_, _ = fmt.Scanln(&yesno)
+		yesno = strings.TrimSpace(yesno)
+		if ! (yesno == "y" || yesno == "Y") {
+			log.Fatal("aborted")
+		}
 	}
-	fmt.Print(color.HiWhiteString("Do you want to continue? [y/N]: "))
-	var yesno string
-	_, _ = fmt.Scanln(&yesno)
-	yesno = strings.TrimSpace(yesno)
-	if ! (yesno == "y" || yesno == "Y") {
-		log.Fatal("aborted")
-	}
-
 	written, err := WriteImage(image, target, inputsize)
+	_, _ = target.Seek(0, 0)
 	if err != nil {
 		fmt.Println("\r[", color.RedString("✘"), "]  Writing image,", written, "bytes written                                                    ")
 		log.Fatal(err)
@@ -226,7 +258,13 @@ func main() {
 	s.Prefix = "[ "
 	s.Suffix = " ]  Syncing"
 	s.Start()
-	err = Sync(image, target)
+	err = image.Sync()
+	if err != nil {
+		s.Stop()
+		fmt.Println("\r[", color.RedString("✘"), "]  Syncing                    ")
+		log.Fatal(err)
+	}
+	err = target.Sync()
 	if err != nil {
 		s.Stop()
 		fmt.Println("\r[", color.RedString("✘"), "]  Syncing                    ")
@@ -235,4 +273,29 @@ func main() {
 		s.Stop()
 		fmt.Println("\r[", color.GreenString("✓"), "]  Syncing                  ")
 	}
+	if ! (force || disable_hash) {
+		s.Prefix = "[ "
+		s.Suffix = " ]  Verifying"
+		s.Start()
+		posthash := sha256.New()
+		_, err = io.CopyN(posthash, target, inputsize)
+		presum := fmt.Sprintf("%x", prehash.Sum(nil))
+		postsum := fmt.Sprintf("%x", posthash.Sum(nil))
+		if err != nil || presum != postsum {
+			s.Stop()
+			fmt.Println("\r[", color.RedString("✘"), "]  Verifying                    ")
+			log.Fatal(err)
+		} else {
+			s.Stop()
+			fmt.Println("\r[", color.GreenString("✓"), "]  Verifying                  ")
+		}
+	}
+	err = image.Close()
+	if err != nil {
+		log.Fatal(err)
+	}
+	err = target.Close()
+	if err != nil {
+		log.Fatal(err)
+	}
 }