Add secure byte slice erase helper; add alternative input methods for Windows

back/security.go

@@ -0,0 +1,9 @@
+package back
+
+// EraseBytesSecurely overwrites all
+// bytes in a slice with zeros.
+func EraseBytesSecurely(input []byte) {
+	for i := range input {
+		input[i] = 0
+	}
+}

front/input_OTHER.go

@@ -1,3 +1,5 @@
+//go:build !windows
+
 package front
 
 import (
@@ -5,8 +7,6 @@ import (
 	"fmt"
 	"os"
 	"strings"
-
-	"golang.org/x/term"
 )
 
 // Input prompts the user for input and returns the input as a string.
@@ -17,14 +17,6 @@ func Input(prompt string) string {
 	return strings.TrimRight(userInput, "\n\r ") // remove trailing newlines, carriage returns, and spaces
 }
 
-// InputHidden prompts the user for input and returns the input as a byte array, hiding the input from the terminal.
-func InputHidden(prompt string) []byte {
-	fmt.Print(prompt + " ")
-	byteInput, _ := term.ReadPassword(int(os.Stdin.Fd()))
-	fmt.Println()
-	return byteInput
-}
-
 // InputBinary prompts the user with a yes/no question and returns the response as a boolean.
 func InputBinary(prompt string) bool {
 	reader := bufio.NewReader(os.Stdin)
@@ -49,11 +41,3 @@ func InputInt(prompt string, min, max int) int {
 		fmt.Println()
 	}
 }
-
-// InputMenuGen prompts the user with a menu and returns the user's choice as an integer.
-func InputMenuGen(prompt string, options []string) int {
-	for i, option := range options {
-		fmt.Printf("%d. %s\n", i+1, option)
-	}
-	return InputInt("\n"+prompt, 1, len(options))
-}

front/input_WIN.go

@@ -0,0 +1,109 @@
+//go:build windows
+
+package front
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+	"syscall"
+	"time"
+	"unsafe"
+)
+
+var (
+	kernel32             = syscall.NewLazyDLL("kernel32.dll")
+	procGetStdHandle     = kernel32.NewProc("GetStdHandle")
+	procPeekConsoleInput = kernel32.NewProc("PeekConsoleInputW")
+	procReadConsoleInput = kernel32.NewProc("ReadConsoleInputW")
+)
+
+const (
+	stdInputHandle = ^uintptr(10) - 1 // STD_INPUT_HANDLE = -10
+)
+
+type inputRecord struct {
+	EventType uint16
+	_         [2]byte // padding
+	Event     [16]byte
+}
+
+// pollForInput checks if input is available without blocking
+func pollForInput() bool {
+	handle, _, _ := procGetStdHandle.Call(stdInputHandle)
+	var numEvents uint32
+	var record inputRecord
+
+	ret, _, _ := procPeekConsoleInput.Call(
+		handle,
+		uintptr(unsafe.Pointer(&record)),
+		1,
+		uintptr(unsafe.Pointer(&numEvents)),
+	)
+
+	return ret != 0 && numEvents > 0
+}
+
+// Input prompts the user for input and returns the input as a string.
+// Uses polling to be more responsive to interrupts on Windows.
+func Input(prompt string) string {
+	fmt.Print(prompt + " ")
+
+	// Poll until input is available
+	for !pollForInput() {
+		time.Sleep(50 * time.Millisecond)
+	}
+
+	reader := bufio.NewReader(os.Stdin)
+	userInput, _ := reader.ReadString('\n')
+	return strings.TrimRight(userInput, "\n\r ") // remove trailing newlines, carriage returns, and spaces
+}
+
+// InputBinary prompts the user with a yes/no question and returns the response as a boolean.
+// Uses polling to be more responsive to interrupts on Windows.
+func InputBinary(prompt string) bool {
+	fmt.Print(prompt + " (y/N) ")
+
+	// Poll until input is available
+	for !pollForInput() {
+		time.Sleep(50 * time.Millisecond)
+	}
+
+	reader := bufio.NewReader(os.Stdin)
+	char, _, _ := reader.ReadRune()
+	if char == 'y' || char == 'Y' {
+		return true
+	}
+	return false
+}
+
+// InputInt prompts the user for input and returns the input as an integer.
+// A negative min/max value will disable the respective limit.
+// Uses polling to be more responsive to interrupts on Windows.
+func InputInt(prompt string, min, max int) int {
+	reader := bufio.NewReader(os.Stdin)
+	for {
+		fmt.Print(prompt + " ")
+
+		// Poll until input is available
+		for !pollForInput() {
+			time.Sleep(50 * time.Millisecond)
+		}
+
+		line, err := reader.ReadString('\n')
+		if err != nil {
+			fmt.Println()
+			continue
+		}
+
+		line = strings.TrimSpace(line)
+		userInput, err := strconv.Atoi(line)
+
+		if err == nil && (userInput >= min || min < 0) && (userInput <= max || max < 0) {
+			return userInput
+		}
+		fmt.Println()
+	}
+}

front/input_common.go

@@ -0,0 +1,24 @@
+package front
+
+import (
+	"fmt"
+	"os"
+
+	"golang.org/x/term"
+)
+
+// InputMenuGen prompts the user with a menu and returns the user's choice as an integer.
+func InputMenuGen(prompt string, options []string) int {
+	for i, option := range options {
+		fmt.Printf("%d. %s\n", i+1, option)
+	}
+	return InputInt("\n"+prompt, 1, len(options))
+}
+
+// InputHidden prompts the user for input and returns the input as a byte array, hiding the input from the terminal.
+func InputHidden(prompt string) []byte {
+	fmt.Print(prompt + " ")
+	byteInput, _ := term.ReadPassword(int(os.Stdin.Fd()))
+	fmt.Println()
+	return byteInput
+}

go.mod

@@ -1,7 +1,7 @@
 module github.com/rwinkhart/go-boilerplate
 
-go 1.25.5
+go 1.25.6
 
-require golang.org/x/term v0.38.0
+require golang.org/x/term v0.39.0
 
-require golang.org/x/sys v0.39.0 // indirect
+require golang.org/x/sys v0.40.0 // indirect

go.sum

@@ -1,4 +1,4 @@
-golang.org/x/sys v0.39.0 h1:CvCKL8MeisomCi6qNZ+wbb0DN9E5AATixKsvNtMoMFk=
-golang.org/x/sys v0.39.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
-golang.org/x/term v0.38.0 h1:PQ5pkm/rLO6HnxFR7N2lJHOZX6Kez5Y1gDSJla6jo7Q=
-golang.org/x/term v0.38.0/go.mod h1:bSEAKrOT1W+VSu9TSCMtoGEOUcKxOKgl3LE5QEF/xVg=
+golang.org/x/sys v0.40.0 h1:DBZZqJ2Rkml6QMQsZywtnjnnGvHza6BTfYFWY9kjEWQ=
+golang.org/x/sys v0.40.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/term v0.39.0 h1:RclSuaJf32jOqZz74CkPA9qFuVTX7vhLlpfj/IGWlqY=
+golang.org/x/term v0.39.0/go.mod h1:yxzUCTP/U+FzoxfdKmLaA0RV1WgE0VY7hXBwKtY/4ww=