Split down into multiple functions

sign/helpers.go

@@ -7,7 +7,6 @@ import (
 	"fmt"
 	"io"
 	"math"
-	"os"
 	"strings"
 	"time"
 
@@ -196,35 +195,3 @@ func isASCII(s string) bool {
 	}
 	return true
 }
-
-// CopyFile copies a file from src to dst.
-// It's a replacement for os.Rename that works across filesystems.
-func CopyFile(src, dst string) error {
-	// Open the source file
-	srcFile, err := os.Open(src)
-	if err != nil {
-		return fmt.Errorf("failed to open source file: %w", err)
-	}
-	defer srcFile.Close()
-
-	// Create the destination directory if it doesn't exist
-	dstDir := dst[:strings.LastIndex(dst, "/")]
-	if err := os.MkdirAll(dstDir, 0o755); err != nil {
-		return fmt.Errorf("failed to create destination directory: %w", err)
-	}
-
-	// Create the destination file
-	dstFile, err := os.Create(dst)
-	if err != nil {
-		return fmt.Errorf("failed to create destination file: %w", err)
-	}
-	defer dstFile.Close()
-
-	// Copy the contents
-	_, err = io.Copy(dstFile, srcFile)
-	if err != nil {
-		return fmt.Errorf("failed to copy file contents: %w", err)
-	}
-
-	return nil
-}