|
| 1 | +use std::fs; |
| 2 | +use std::path::{Path, PathBuf}; |
| 3 | +use tauri::{AppHandle, Manager}; |
| 4 | +use uuid::Uuid; |
| 5 | + |
| 6 | +const MAX_SKIN_BYTES: u64 = 4 * 1024 * 1024; |
| 7 | + |
| 8 | +fn image_extension(path: &Path, bytes: &[u8]) -> Option<&'static str> { |
| 9 | + let extension = path.extension()?.to_str()?.to_ascii_lowercase(); |
| 10 | + let valid = match extension.as_str() { |
| 11 | + "png" => bytes.starts_with(b"\x89PNG\r\n\x1a\n"), |
| 12 | + "jpg" | "jpeg" => bytes.starts_with(&[0xff, 0xd8, 0xff]), |
| 13 | + "webp" => bytes.len() >= 12 && &bytes[0..4] == b"RIFF" && &bytes[8..12] == b"WEBP", |
| 14 | + "gif" => bytes.starts_with(b"GIF87a") || bytes.starts_with(b"GIF89a"), |
| 15 | + _ => false, |
| 16 | + }; |
| 17 | + if !valid { |
| 18 | + return None; |
| 19 | + } |
| 20 | + Some(match extension.as_str() { |
| 21 | + "png" => "png", |
| 22 | + "jpg" | "jpeg" => "jpg", |
| 23 | + "webp" => "webp", |
| 24 | + "gif" => "gif", |
| 25 | + _ => return None, |
| 26 | + }) |
| 27 | +} |
| 28 | + |
| 29 | +pub fn skin_path(data_dir: &Path, relative: &str) -> Result<PathBuf, String> { |
| 30 | + let relative_path = Path::new(relative); |
| 31 | + if relative_path.is_absolute() |
| 32 | + || relative_path.components().any(|component| matches!(component, std::path::Component::ParentDir)) |
| 33 | + || !relative.starts_with("skins/") |
| 34 | + { |
| 35 | + return Err("skin path is not allowed".to_string()); |
| 36 | + } |
| 37 | + let root = data_dir.join("skins").canonicalize().unwrap_or_else(|_| data_dir.join("skins")); |
| 38 | + let candidate = data_dir.join(relative_path); |
| 39 | + if candidate.parent().and_then(|parent| parent.canonicalize().ok()).as_deref() != Some(root.as_path()) { |
| 40 | + return Err("skin path is outside the managed directory".to_string()); |
| 41 | + } |
| 42 | + Ok(candidate) |
| 43 | +} |
| 44 | + |
| 45 | +#[tauri::command] |
| 46 | +pub fn import_skin_image(source: String, app: AppHandle) -> Result<String, String> { |
| 47 | + let source_path = Path::new(&source); |
| 48 | + let metadata = fs::metadata(source_path).map_err(|_| "skin file cannot be read".to_string())?; |
| 49 | + if !metadata.is_file() || metadata.len() > MAX_SKIN_BYTES { |
| 50 | + return Err("skin file is missing or exceeds the 4 MB limit".to_string()); |
| 51 | + } |
| 52 | + let bytes = fs::read(source_path).map_err(|_| "skin file cannot be read".to_string())?; |
| 53 | + let extension = image_extension(source_path, &bytes) |
| 54 | + .ok_or_else(|| "only valid PNG, JPEG, WebP, or GIF images are allowed".to_string())?; |
| 55 | + let data_dir = app.path().app_data_dir().map_err(|e| e.to_string())?; |
| 56 | + let skin_dir = data_dir.join("skins"); |
| 57 | + fs::create_dir_all(&skin_dir).map_err(|e| e.to_string())?; |
| 58 | + let filename = format!("{}.{}", Uuid::new_v4(), extension); |
| 59 | + fs::write(skin_dir.join(&filename), bytes).map_err(|e| e.to_string())?; |
| 60 | + Ok(skin_dir.join(filename).to_string_lossy().into_owned()) |
| 61 | +} |
| 62 | + |
| 63 | +#[cfg(test)] |
| 64 | +mod tests { |
| 65 | + use super::{image_extension, skin_path, MAX_SKIN_BYTES}; |
| 66 | + use std::path::Path; |
| 67 | + |
| 68 | + #[test] |
| 69 | + fn rejects_absolute_and_traversal_skin_paths() { |
| 70 | + let root = std::env::temp_dir().join("timelens-skin-test"); |
| 71 | + assert!(skin_path(Path::new(&root), "C:/secret.png").is_err()); |
| 72 | + assert!(skin_path(Path::new(&root), "skins/../secret.png").is_err()); |
| 73 | + assert!(skin_path(Path::new(&root), "skins/nested/secret.png").is_err()); |
| 74 | + } |
| 75 | + |
| 76 | + #[test] |
| 77 | + fn accepts_only_matching_image_magic_bytes() { |
| 78 | + assert_eq!(image_extension(Path::new("skin.png"), b"\x89PNG\r\n\x1a\nrest"), Some("png")); |
| 79 | + assert_eq!(image_extension(Path::new("skin.png"), b"not-a-png"), None); |
| 80 | + assert_eq!(image_extension(Path::new("skin.jpg"), &[0xff, 0xd8, 0xff, 0xe0]), Some("jpg")); |
| 81 | + assert_eq!(image_extension(Path::new("skin.webp"), b"RIFF1234WEBP"), Some("webp")); |
| 82 | + assert_eq!(image_extension(Path::new("skin.gif"), b"GIF89arest"), Some("gif")); |
| 83 | + assert_eq!(image_extension(Path::new("skin.svg"), b"<svg>"), None); |
| 84 | + } |
| 85 | + |
| 86 | + #[test] |
| 87 | + fn keeps_the_four_megabyte_upload_limit() { |
| 88 | + assert_eq!(MAX_SKIN_BYTES, 4 * 1024 * 1024); |
| 89 | + } |
| 90 | +} |
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