fix(go): protect CLI install credentials

sdks/go/cmd/elydora/terminal_windows.go

@@ -0,0 +1,116 @@
+//go:build windows
+
+package main
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"syscall"
+)
+
+const (
+	windowsEnableProcessedInput  = 0x0001
+	windowsEnableLineInput       = 0x0002
+	windowsEnableEchoInput       = 0x0004
+	windowsEnableProcessedOutput = 0x0001
+)
+
+var setConsoleMode = syscall.NewLazyDLL("kernel32.dll").NewProc("SetConsoleMode")
+
+func isInteractiveTerminal(file *os.File) bool {
+	var mode uint32
+	return syscall.GetConsoleMode(syscall.Handle(file.Fd()), &mode) == nil
+}
+
+func readHiddenLine(file *os.File) (raw []byte, returnErr error) {
+	handle := syscall.Handle(file.Fd())
+	var originalMode uint32
+	if err := syscall.GetConsoleMode(handle, &originalMode); err != nil {
+		return nil, fmt.Errorf("read console mode: %w", err)
+	}
+	hiddenMode := originalMode &^ (windowsEnableEchoInput | windowsEnableLineInput)
+	hiddenMode |= windowsEnableProcessedInput | windowsEnableProcessedOutput
+	if err := updateConsoleMode(handle, hiddenMode); err != nil {
+		return nil, fmt.Errorf("disable terminal echo: %w", err)
+	}
+	defer func() {
+		if err := updateConsoleMode(handle, originalMode); err != nil {
+			returnErr = errors.Join(returnErr, fmt.Errorf("restore console mode: %w", err))
+		}
+	}()
+
+	process, err := syscall.GetCurrentProcess()
+	if err != nil {
+		return nil, fmt.Errorf("get current process: %w", err)
+	}
+	var duplicate syscall.Handle
+	if err := syscall.DuplicateHandle(
+		process,
+		handle,
+		process,
+		&duplicate,
+		0,
+		false,
+		syscall.DUPLICATE_SAME_ACCESS,
+	); err != nil {
+		return nil, fmt.Errorf("duplicate terminal handle: %w", err)
+	}
+	input := os.NewFile(uintptr(duplicate), file.Name())
+	if input == nil {
+		_ = syscall.CloseHandle(duplicate)
+		return nil, errors.New("create terminal reader from duplicate handle")
+	}
+	defer func() {
+		if err := input.Close(); err != nil {
+			returnErr = errors.Join(returnErr, fmt.Errorf("close terminal reader: %w", err))
+		}
+	}()
+
+	return readWindowsPasswordLine(input)
+}
+
+func updateConsoleMode(handle syscall.Handle, mode uint32) error {
+	result, _, callErr := setConsoleMode.Call(uintptr(handle), uintptr(mode))
+	if result != 0 {
+		return nil
+	}
+	if callErr != syscall.Errno(0) {
+		return callErr
+	}
+	return syscall.EINVAL
+}
+
+func readWindowsPasswordLine(reader io.Reader) ([]byte, error) {
+	var value []byte
+	var buffer [1]byte
+	for {
+		read, err := reader.Read(buffer[:])
+		if read > 0 {
+			switch buffer[0] {
+			case '\b':
+				if len(value) > 0 {
+					value = value[:len(value)-1]
+				}
+			case '\r':
+				return value, nil
+			case '\n':
+			default:
+				value = append(value, buffer[0])
+				if len(value) > maxSecretFileBytes {
+					clear(value)
+					return nil, fmt.Errorf("hidden input exceeds %d bytes", maxSecretFileBytes)
+				}
+			}
+			continue
+		}
+		if err != nil {
+			if errors.Is(err, io.EOF) && len(value) > 0 {
+				return value, nil
+			}
+			clear(value)
+			return nil, err
+		}
+	}
+}