| 1 | //! Community-skill installer (#140). |
| 2 | //! |
| 3 | //! Pulls user-authored skills from GitHub or direct tarball URLs, validates them |
| 4 | //! against a path-traversal- and size-bounded extractor, and writes them into |
| 5 | //! `<skills_dir>/<name>/`. No backend service, no auto-execution: every install |
| 6 | //! is gated by the per-domain [`crate::network_policy::NetworkPolicy`] and |
| 7 | //! validation rejects any tarball entry that escapes the destination directory. |
| 8 | //! |
| 9 | //! Public surface: |
| 10 | //! |
| 11 | //! * [`InstallSource`] — `github:owner/repo`, raw URL, or curated registry |
| 12 | //! name. Parsed from a single string with [`InstallSource::parse`]. |
| 13 | //! * [`install`] / [`update`] / [`uninstall`] — async install, atomic update, |
| 14 | //! and clean uninstall. All three preserve a `.installed-from` marker so the |
| 15 | //! bundled `skill-creator` (which lacks the marker) is never touched. |
| 16 | //! * [`InstallOutcome`] — `Installed` / `NeedsApproval(host)` / |
| 17 | //! `NetworkDenied(host)`. The `NeedsApproval` variant is returned without |
| 18 | //! side effects so the caller (slash-command, runtime API, etc.) can route |
| 19 | //! through its own approval flow. |
| 20 | //! |
| 21 | //! # Hard rules |
| 22 | //! |
| 23 | //! * Validation extracts to a temp directory first. The destination path is |
| 24 | //! only created (via atomic rename) once the tarball clears every check. |
| 25 | //! Half-installed skills can never appear on disk. |
| 26 | //! * Path traversal rejection covers both `..` segments and absolute paths. |
| 27 | //! Symlinks inside the selected skill subtree are rejected — there's no use |
| 28 | //! case for them in a SKILL.md bundle and they're a notorious foothold for |
| 29 | //! escape. Multi-skill repository archives may contain unrelated symlinks |
| 30 | //! outside that selected subtree; those entries are ignored and never |
| 31 | //! extracted. |
| 32 | //! * No `+x` is granted on extracted files. The optional `/skill trust <name>` |
| 33 | //! command writes a `.trusted` marker; tool-execution gating is a separate |
| 34 | //! concern that lives next to the tool registry. |
| 35 | //! * Claude Code plugin archives that contain multiple skills are rejected with |
| 36 | //! an explicit migration message. Codewhale can install individual |
| 37 | //! `SKILL.md` bundles, including `.claude/skills/<name>/SKILL.md`, but it |
| 38 | //! does not execute `plugin.json` plugin runtimes or custom command bundles. |
| 39 | |
| 40 | use std::fs; |
| 41 | use std::io::{Read, Write}; |
| 42 | use std::path::{Component, Path, PathBuf}; |
| 43 | |
| 44 | use anyhow::{Context, Result, bail}; |
| 45 | use flate2::read::GzDecoder; |
| 46 | use futures_util::stream::{self, StreamExt}; |
| 47 | use serde::{Deserialize, Serialize}; |
| 48 | use sha2::{Digest, Sha256}; |
| 49 | use thiserror::Error; |
| 50 | |
| 51 | use crate::network_policy::{Decision, NetworkPolicy, host_from_url}; |
| 52 | |
| 53 | fn reqwest_client() -> reqwest::Client { |
| 54 | codewhale_release::platform_http_client_builder() |
| 55 | .build() |
| 56 | .expect("build platform HTTP client") |
| 57 | } |
| 58 | |
| 59 | /// Cache directory for registry-synced skills. |
| 60 | /// |
| 61 | /// Lives at `~/.codewhale/cache/skills/` so it's separate from user-installed |
| 62 | /// skills and can be blown away without losing anything irreplaceable. |
| 63 | pub fn default_cache_skills_dir() -> PathBuf { |
| 64 | crate::config::effective_home_dir().map_or_else( |
| 65 | || PathBuf::from("/tmp/codewhale/cache/skills"), |
| 66 | |p| p.join(".codewhale").join("cache").join("skills"), |
| 67 | ) |
| 68 | } |
| 69 | |
| 70 | /// Default registry. Falls back to a community-curated `index.json` hosted on |
| 71 | /// GitHub raw; users can override via `[skills] registry_url` in config.toml. |
| 72 | pub const DEFAULT_REGISTRY_URL: &str = |
| 73 | "https://raw.githubusercontent.com/Hmbown/deepseek-skills/main/index.json"; |
| 74 | |
| 75 | /// Default per-skill size cap (5 MiB). Honored at unpack time so a malicious |
| 76 | /// gzip bomb can't blow up RAM. |
| 77 | pub const DEFAULT_MAX_SIZE_BYTES: u64 = 5 * 1024 * 1024; |
| 78 | const SYNC_REGISTRY_CONCURRENCY: usize = 8; |
| 79 | |
| 80 | /// File written under each installed skill so [`update`] / [`uninstall`] can |
| 81 | /// recover the original [`InstallSource`] without re-parsing user input. |
| 82 | pub const INSTALLED_FROM_MARKER: &str = ".installed-from"; |
| 83 | |
| 84 | /// File written under each trusted skill. Currently advisory (the install path |
| 85 | /// never auto-runs anything) — the runtime tool-invocation gate consults this |
| 86 | /// marker before executing scripts that ship with the skill. |
| 87 | pub const TRUSTED_MARKER: &str = ".trusted"; |
| 88 | |
| 89 | // ───────────────────────────────────────────────────────────────────────────── |
| 90 | // Source parsing |
| 91 | // ───────────────────────────────────────────────────────────────────────────── |
| 92 | |
| 93 | /// Where a skill is being installed from. See [`InstallSource::parse`] for the |
| 94 | /// accepted spec syntax. |
| 95 | #[derive(Debug, Clone, PartialEq, Eq)] |
| 96 | pub enum InstallSource { |
| 97 | /// `github:owner/repo`. Resolved to |
| 98 | /// `https://github.com/<owner>/<repo>/archive/refs/heads/main.tar.gz` |
| 99 | /// with a `master.tar.gz` fallback on 404. |
| 100 | GitHubRepo(String), |
| 101 | /// Raw `http(s)://…` tarball URL. Used as-is. |
| 102 | DirectUrl(String), |
| 103 | /// Curated registry lookup key. Looked up via the configured `registry_url`. |
| 104 | Registry(String), |
| 105 | } |
| 106 | |
| 107 | impl InstallSource { |
| 108 | /// Parse a user-supplied spec. Empty / whitespace-only input is rejected. |
| 109 | /// |
| 110 | /// * `github:owner/repo` → [`InstallSource::GitHubRepo`] |
| 111 | /// * `https://github.com/owner/repo[.git]` (no path past the repo) → |
| 112 | /// [`InstallSource::GitHubRepo`] |
| 113 | /// * any other `http://` or `https://` prefix → [`InstallSource::DirectUrl`] |
| 114 | /// * anything else → [`InstallSource::Registry`] |
| 115 | pub fn parse(spec: &str) -> Result<Self> { |
| 116 | let trimmed = spec.trim(); |
| 117 | if trimmed.is_empty() { |
| 118 | bail!("install source must not be empty"); |
| 119 | } |
| 120 | if let Some(rest) = trimmed.strip_prefix("github:") { |
| 121 | let rest = rest.trim(); |
| 122 | // Reject obviously bogus values up front. We intentionally accept |
| 123 | // case-insensitive owner/repo so `github:Hmbown/Foo` works. |
| 124 | let (owner, repo) = rest.split_once('/').with_context(|| { |
| 125 | format!("github source must be 'github:owner/repo' (got {spec})") |
| 126 | })?; |
| 127 | let owner = owner.trim(); |
| 128 | let repo = repo.trim().trim_end_matches('/'); |
| 129 | if owner.is_empty() || repo.is_empty() { |
| 130 | bail!("github source must be 'github:owner/repo' (got {spec})"); |
| 131 | } |
| 132 | if owner.contains('/') || repo.contains('/') { |
| 133 | bail!("github source must be 'github:owner/repo' (got {spec})"); |
| 134 | } |
| 135 | return Ok(Self::GitHubRepo(format!("{owner}/{repo}"))); |
| 136 | } |
| 137 | if trimmed.starts_with("https://") || trimmed.starts_with("http://") { |
| 138 | if let Some(repo) = parse_github_browser_url(trimmed) { |
| 139 | return Ok(Self::GitHubRepo(repo)); |
| 140 | } |
| 141 | return Ok(Self::DirectUrl(trimmed.to_string())); |
| 142 | } |
| 143 | Ok(Self::Registry(trimmed.to_string())) |
| 144 | } |
| 145 | } |
| 146 | |
| 147 | /// Detect bare `https://github.com/<owner>/<repo>` URLs (with or without a |
| 148 | /// trailing `.git`) and return `owner/repo`. Returns `None` for any URL that |
| 149 | /// already points at a specific archive / blob / tree path — those are real |
| 150 | /// direct URLs and the caller fetches them as-is. |
| 151 | fn parse_github_browser_url(url: &str) -> Option<String> { |
| 152 | let after_scheme = url |
| 153 | .strip_prefix("https://") |
| 154 | .or_else(|| url.strip_prefix("http://"))?; |
| 155 | let (host, rest) = after_scheme.split_once('/')?; |
| 156 | if !host.eq_ignore_ascii_case("github.com") && !host.eq_ignore_ascii_case("www.github.com") { |
| 157 | return None; |
| 158 | } |
| 159 | let trimmed = rest.trim_end_matches('/'); |
| 160 | let mut parts = trimmed.splitn(3, '/'); |
| 161 | let owner = parts.next()?.trim(); |
| 162 | let repo = parts.next()?.trim().trim_end_matches(".git"); |
| 163 | if owner.is_empty() || repo.is_empty() { |
| 164 | return None; |
| 165 | } |
| 166 | // If there is a third segment, the URL points at a sub-resource |
| 167 | // (`/archive/...`, `/blob/...`, `/tree/...`). Treat that as a real direct |
| 168 | // URL — the user explicitly wants whatever lives at that path. |
| 169 | if parts.next().is_some() { |
| 170 | return None; |
| 171 | } |
| 172 | Some(format!("{owner}/{repo}")) |
| 173 | } |
| 174 | |
| 175 | // ───────────────────────────────────────────────────────────────────────────── |
| 176 | // Outcome / result types |
| 177 | // ───────────────────────────────────────────────────────────────────────────── |
| 178 | |
| 179 | /// Outcome of an install attempt. |
| 180 | #[derive(Debug)] |
| 181 | pub enum InstallOutcome { |
| 182 | /// The skill was installed (or already present and idempotent). |
| 183 | Installed(InstalledSkill), |
| 184 | /// The host requires user approval before the install can proceed. The |
| 185 | /// caller should surface this through whatever approval pathway it has and |
| 186 | /// retry once approved (typically by adding the host to the policy's |
| 187 | /// allow list). |
| 188 | NeedsApproval(String), |
| 189 | /// The host is denied by network policy. The install is aborted. |
| 190 | NetworkDenied(String), |
| 191 | } |
| 192 | |
| 193 | /// Metadata for a successfully installed skill. |
| 194 | #[derive(Debug, Clone)] |
| 195 | pub struct InstalledSkill { |
| 196 | /// Skill name (taken from SKILL.md frontmatter). |
| 197 | pub name: String, |
| 198 | /// Final on-disk path: `<skills_dir>/<name>/`. |
| 199 | pub path: PathBuf, |
| 200 | /// SHA-256 over the downloaded tarball bytes. Used by [`update`] to detect |
| 201 | /// upstream changes without re-extracting; also surfaced for telemetry / |
| 202 | /// future signature-verification work. |
| 203 | #[expect(dead_code)] |
| 204 | pub source_checksum: String, |
| 205 | } |
| 206 | |
| 207 | /// Result of an [`update`] call. |
| 208 | #[derive(Debug)] |
| 209 | pub enum UpdateResult { |
| 210 | /// Upstream tarball is byte-identical to the on-disk checksum; no action. |
| 211 | NoChange, |
| 212 | /// Upstream changed and the on-disk install was atomically replaced. |
| 213 | Updated(InstalledSkill), |
| 214 | /// Network policy short-circuited the update. Same semantics as |
| 215 | /// [`InstallOutcome::NeedsApproval`]. |
| 216 | NeedsApproval(String), |
| 217 | /// Network policy denied the update. |
| 218 | NetworkDenied(String), |
| 219 | } |
| 220 | |
| 221 | /// Errors that can happen during install. Most variants are flattened into |
| 222 | /// `anyhow::Error` at the public boundary; this enum is used internally so |
| 223 | /// tests can pattern-match without parsing strings. |
| 224 | #[derive(Debug, Error)] |
| 225 | pub enum InstallError { |
| 226 | #[error("entry escapes destination directory: {0}")] |
| 227 | PathTraversal(String), |
| 228 | #[error("entry is too large; uncompressed total would exceed {limit} bytes")] |
| 229 | OversizedTarball { limit: u64 }, |
| 230 | #[error("missing SKILL.md in archive")] |
| 231 | MissingSkillMd, |
| 232 | #[error("SKILL.md frontmatter missing required field: {0}")] |
| 233 | MissingFrontmatterField(&'static str), |
| 234 | #[error("symlinks are not allowed in skill tarballs")] |
| 235 | SymlinkRejected, |
| 236 | #[error( |
| 237 | "Claude Code plugin archive contains multiple SKILL.md entries; Codewhale installs one SKILL.md bundle at a time and does not run plugin.json/custom-command runtimes. Install or migrate an individual skills/<name> directory instead" |
| 238 | )] |
| 239 | ClaudePluginBundle, |
| 240 | #[error("skill '{0}' is already installed; use update or remove it first")] |
| 241 | AlreadyInstalled(String), |
| 242 | #[error("skill '{0}' was not installed via /skill install (no .installed-from marker)")] |
| 243 | NotInstalledHere(String), |
| 244 | } |
| 245 | |
| 246 | // ───────────────────────────────────────────────────────────────────────────── |
| 247 | // Public API |
| 248 | // ───────────────────────────────────────────────────────────────────────────── |
| 249 | |
| 250 | /// Install a community skill into `skills_dir`. |
| 251 | /// |
| 252 | /// Steps: |
| 253 | /// |
| 254 | /// 1. Resolve `source` to one or more candidate URLs (GitHub adds a |
| 255 | /// `master` fallback after `main`). |
| 256 | /// 2. Consult `network` for the host. `Allow` proceeds; `Deny` returns |
| 257 | /// [`InstallOutcome::NetworkDenied`]; `Prompt` returns |
| 258 | /// [`InstallOutcome::NeedsApproval`] without touching disk. |
| 259 | /// 3. Stream the tarball into a tempfile (capped at `max_size`). |
| 260 | /// 4. Validate the archive (path-traversal, size, no symlinks in the selected |
| 261 | /// skill subtree, SKILL.md present with required frontmatter fields) into a |
| 262 | /// sibling `<name>.tmp/` directory. |
| 263 | /// 5. Atomic-rename `<name>.tmp/` → `<name>/`. |
| 264 | /// 6. Write `.installed-from` and return [`InstalledSkill`]. |
| 265 | /// |
| 266 | /// `update = false` rejects an existing destination. Pass `update = true` |
| 267 | /// from [`update`] to allow replacement. |
| 268 | /// |
| 269 | /// Convenience wrapper over [`install_with_registry`] that uses the bundled |
| 270 | /// [`DEFAULT_REGISTRY_URL`]. Public for downstream consumers (tests, runtime |
| 271 | /// API) even though the slash-command path always goes through |
| 272 | /// [`install_with_registry`] so the user's configured registry wins. |
| 273 | #[cfg_attr(not(test), expect(dead_code))] |
| 274 | #[cfg_attr(test, allow(dead_code))] |
| 275 | pub async fn install( |
| 276 | source: InstallSource, |
| 277 | skills_dir: &Path, |
| 278 | max_size: u64, |
| 279 | network: &NetworkPolicy, |
| 280 | update: bool, |
| 281 | ) -> Result<InstallOutcome> { |
| 282 | install_with_registry( |
| 283 | source, |
| 284 | skills_dir, |
| 285 | max_size, |
| 286 | network, |
| 287 | update, |
| 288 | DEFAULT_REGISTRY_URL, |
| 289 | ) |
| 290 | .await |
| 291 | } |
| 292 | |
| 293 | /// Same as [`install`] but lets the caller override the registry URL. Useful |
| 294 | /// for tests; the slash-command path always uses the configured registry. |
| 295 | pub async fn install_with_registry( |
| 296 | source: InstallSource, |
| 297 | skills_dir: &Path, |
| 298 | max_size: u64, |
| 299 | network: &NetworkPolicy, |
| 300 | update: bool, |
| 301 | registry_url: &str, |
| 302 | ) -> Result<InstallOutcome> { |
| 303 | let urls = candidate_urls(&source, network, registry_url).await?; |
| 304 | let urls = match urls { |
| 305 | UrlResolution::Resolved(urls) => urls, |
| 306 | UrlResolution::NeedsApproval(host) => return Ok(InstallOutcome::NeedsApproval(host)), |
| 307 | UrlResolution::Denied(host) => return Ok(InstallOutcome::NetworkDenied(host)), |
| 308 | }; |
| 309 | |
| 310 | // Try each URL in order — GitHub returns 404 for `main` on master-only |
| 311 | // repos, and we don't want to fail the install on that. |
| 312 | let (bytes, source_url) = match download_first_success(&urls, network, max_size).await? { |
| 313 | DownloadOutcome::Bytes { bytes, url } => (bytes, url), |
| 314 | DownloadOutcome::NeedsApproval(host) => return Ok(InstallOutcome::NeedsApproval(host)), |
| 315 | DownloadOutcome::Denied(host) => return Ok(InstallOutcome::NetworkDenied(host)), |
| 316 | }; |
| 317 | |
| 318 | // Compute a checksum before unpacking so [`update`] can detect upstream |
| 319 | // no-op changes without redoing the extract. |
| 320 | let checksum = sha256_hex(&bytes); |
| 321 | |
| 322 | let staged = stage_tarball(&bytes, skills_dir, max_size)?; |
| 323 | |
| 324 | // Move the staged dir into its final location. If `update` is set and the |
| 325 | // destination exists, replace it; otherwise reject. |
| 326 | // Keep any backup until content digest + marker write succeed so a failed |
| 327 | // finalize can restore the previous install. |
| 328 | let final_path = skills_dir.join(&staged.skill_name); |
| 329 | let mut backup_path: Option<PathBuf> = None; |
| 330 | if tokio::fs::try_exists(&final_path).await.unwrap_or(false) { |
| 331 | if !update { |
| 332 | // Clean up the staging dir before returning the error. |
| 333 | let _ = tokio::fs::remove_dir_all(&staged.staged_path).await; |
| 334 | return Err(InstallError::AlreadyInstalled(staged.skill_name).into()); |
| 335 | } |
| 336 | // Same ownership gate as plugins/install/place.rs: an update may only |
| 337 | // replace a tree this installer created. The tarball's top-level name |
| 338 | // is not proof of ownership — without the marker we would delete a |
| 339 | // user-authored or system skill that happened to share the name. |
| 340 | if let Err(err) = reject_unmarked_update(&final_path, &staged.skill_name) { |
| 341 | let _ = tokio::fs::remove_dir_all(&staged.staged_path).await; |
| 342 | return Err(err.into()); |
| 343 | } |
| 344 | let backup = skills_dir.join(format!("{}.bak", staged.skill_name)); |
| 345 | if tokio::fs::try_exists(&backup).await.unwrap_or(false) { |
| 346 | tokio::fs::remove_dir_all(&backup).await.ok(); |
| 347 | } |
| 348 | tokio::fs::rename(&final_path, &backup) |
| 349 | .await |
| 350 | .with_context(|| { |
| 351 | format!( |
| 352 | "failed to backup existing skill at {}", |
| 353 | final_path.display() |
| 354 | ) |
| 355 | })?; |
| 356 | if let Err(err) = tokio::fs::rename(&staged.staged_path, &final_path).await { |
| 357 | tokio::fs::rename(&backup, &final_path).await.ok(); |
| 358 | return Err(err).context("failed to install staged skill"); |
| 359 | } |
| 360 | backup_path = Some(backup); |
| 361 | } else { |
| 362 | if let Some(parent) = final_path.parent() { |
| 363 | tokio::fs::create_dir_all(parent).await.with_context(|| { |
| 364 | format!("failed to create skills directory {}", parent.display()) |
| 365 | })?; |
| 366 | } |
| 367 | tokio::fs::rename(&staged.staged_path, &final_path) |
| 368 | .await |
| 369 | .context("failed to install staged skill")?; |
| 370 | } |
| 371 | |
| 372 | // Write the marker last so a partial install never leaves a stale |
| 373 | // .installed-from on disk. Prefer v2 with package content digest. |
| 374 | let spec = source_spec_string(&source); |
| 375 | let content_digest = match super::package_digest::compute_package_digest(&final_path) { |
| 376 | Ok(digest) => digest, |
| 377 | Err(err) => { |
| 378 | let _ = tokio::fs::remove_dir_all(&final_path).await; |
| 379 | if let Some(backup) = backup_path.take() { |
| 380 | let _ = tokio::fs::rename(&backup, &final_path).await; |
| 381 | } |
| 382 | return Err(anyhow::anyhow!( |
| 383 | "installed package failed content digest validation: {err}" |
| 384 | )); |
| 385 | } |
| 386 | }; |
| 387 | if let Err(err) = write_installed_from_v2( |
| 388 | &final_path, |
| 389 | &spec, |
| 390 | Some(&source_url), |
| 391 | &checksum, |
| 392 | &content_digest, |
| 393 | &staged.skill_name, |
| 394 | ) { |
| 395 | let _ = tokio::fs::remove_dir_all(&final_path).await; |
| 396 | if let Some(backup) = backup_path.take() { |
| 397 | let _ = tokio::fs::rename(&backup, &final_path).await; |
| 398 | } |
| 399 | return Err(err); |
| 400 | } |
| 401 | if let Some(backup) = backup_path { |
| 402 | tokio::fs::remove_dir_all(&backup).await.ok(); |
| 403 | } |
| 404 | |
| 405 | Ok(InstallOutcome::Installed(InstalledSkill { |
| 406 | name: staged.skill_name, |
| 407 | path: final_path, |
| 408 | source_checksum: checksum, |
| 409 | })) |
| 410 | } |
| 411 | |
| 412 | /// Re-fetch a previously installed skill and replace it on disk if the |
| 413 | /// upstream tarball changed. |
| 414 | /// |
| 415 | /// Reads `.installed-from` to recover the original [`InstallSource`], so |
| 416 | /// a skill installed via `/skill install github:foo/bar` can be updated via |
| 417 | /// `/skill update bar` without the user re-typing the spec. |
| 418 | /// |
| 419 | /// Convenience wrapper over [`update_with_registry`]. |
| 420 | #[cfg_attr(not(test), expect(dead_code))] |
| 421 | #[cfg_attr(test, allow(dead_code))] |
| 422 | pub async fn update( |
| 423 | name: &str, |
| 424 | skills_dir: &Path, |
| 425 | max_size: u64, |
| 426 | network: &NetworkPolicy, |
| 427 | ) -> Result<UpdateResult> { |
| 428 | update_with_registry(name, skills_dir, max_size, network, DEFAULT_REGISTRY_URL).await |
| 429 | } |
| 430 | |
| 431 | /// Same as [`update`] but lets the caller override the registry URL. |
| 432 | pub async fn update_with_registry( |
| 433 | name: &str, |
| 434 | skills_dir: &Path, |
| 435 | max_size: u64, |
| 436 | network: &NetworkPolicy, |
| 437 | registry_url: &str, |
| 438 | ) -> Result<UpdateResult> { |
| 439 | let target = skill_target_path(name, skills_dir)?; |
| 440 | if tokio::fs::try_exists(&target).await.unwrap_or(false) { |
| 441 | ensure_target_within_skills_dir(&target, skills_dir)?; |
| 442 | } |
| 443 | let marker_path = target.join(INSTALLED_FROM_MARKER); |
| 444 | if !tokio::fs::try_exists(&marker_path).await.unwrap_or(false) { |
| 445 | return Err(InstallError::NotInstalledHere(name.to_string()).into()); |
| 446 | } |
| 447 | let marker_body = tokio::fs::read_to_string(&marker_path) |
| 448 | .await |
| 449 | .with_context(|| format!("failed to read {}", marker_path.display()))?; |
| 450 | let marker: InstalledFromMarker = serde_json::from_str(&marker_body) |
| 451 | .with_context(|| format!("malformed {INSTALLED_FROM_MARKER} for {name}"))?; |
| 452 | if !is_registry_updatable_spec(&marker.spec) { |
| 453 | bail!( |
| 454 | "skill '{name}' was imported locally (spec '{}') and cannot be updated from a registry; \ |
| 455 | re-import or remove it first", |
| 456 | marker.spec |
| 457 | ); |
| 458 | } |
| 459 | |
| 460 | // Re-resolve the URL, taking the existing checksum as a short-circuit hint: |
| 461 | // we still hit the network so the user gets a useful "no upstream change" |
| 462 | // signal, but we skip the unpack step if the bytes match. |
| 463 | let source = InstallSource::parse(&marker.spec)?; |
| 464 | let urls = match candidate_urls(&source, network, registry_url).await? { |
| 465 | UrlResolution::Resolved(urls) => urls, |
| 466 | UrlResolution::NeedsApproval(host) => return Ok(UpdateResult::NeedsApproval(host)), |
| 467 | UrlResolution::Denied(host) => return Ok(UpdateResult::NetworkDenied(host)), |
| 468 | }; |
| 469 | let (bytes, _url) = match download_first_success(&urls, network, max_size).await? { |
| 470 | DownloadOutcome::Bytes { bytes, url } => (bytes, url), |
| 471 | DownloadOutcome::NeedsApproval(host) => return Ok(UpdateResult::NeedsApproval(host)), |
| 472 | DownloadOutcome::Denied(host) => return Ok(UpdateResult::NetworkDenied(host)), |
| 473 | }; |
| 474 | |
| 475 | let checksum = sha256_hex(&bytes); |
| 476 | if checksum == marker.source_checksum() { |
| 477 | return Ok(UpdateResult::NoChange); |
| 478 | } |
| 479 | |
| 480 | // Bytes changed — fall back to the regular install path with `update = true` |
| 481 | // so we get the same atomic-replace semantics. Content updates must not |
| 482 | // inherit a previous trust marker. |
| 483 | let trust_path = target.join(TRUSTED_MARKER); |
| 484 | let had_trust = tokio::fs::try_exists(&trust_path).await.unwrap_or(false); |
| 485 | let outcome = |
| 486 | install_with_registry(source, skills_dir, max_size, network, true, registry_url).await?; |
| 487 | match &outcome { |
| 488 | InstallOutcome::Installed(installed) => { |
| 489 | if had_trust { |
| 490 | let _ = tokio::fs::remove_file(installed.path.join(TRUSTED_MARKER)).await; |
| 491 | } |
| 492 | } |
| 493 | InstallOutcome::NeedsApproval(_) | InstallOutcome::NetworkDenied(_) => {} |
| 494 | } |
| 495 | match outcome { |
| 496 | InstallOutcome::Installed(installed) => Ok(UpdateResult::Updated(installed)), |
| 497 | InstallOutcome::NeedsApproval(host) => Ok(UpdateResult::NeedsApproval(host)), |
| 498 | InstallOutcome::NetworkDenied(host) => Ok(UpdateResult::NetworkDenied(host)), |
| 499 | } |
| 500 | } |
| 501 | |
| 502 | /// Remove a community-installed skill. |
| 503 | /// |
| 504 | /// Refuses to touch any directory that doesn't carry the `.installed-from` |
| 505 | /// marker — that's our cue that it's user-owned and not a system skill. |
| 506 | pub fn uninstall(name: &str, skills_dir: &Path) -> Result<()> { |
| 507 | let target = skill_target_path(name, skills_dir)?; |
| 508 | if !target.exists() { |
| 509 | bail!("skill '{name}' is not installed at {}", target.display()); |
| 510 | } |
| 511 | ensure_target_within_skills_dir(&target, skills_dir)?; |
| 512 | if !target.join(INSTALLED_FROM_MARKER).exists() { |
| 513 | return Err(InstallError::NotInstalledHere(name.to_string()).into()); |
| 514 | } |
| 515 | fs::remove_dir_all(&target) |
| 516 | .with_context(|| format!("failed to remove {}", target.display()))?; |
| 517 | Ok(()) |
| 518 | } |
| 519 | |
| 520 | /// Mark a community-installed skill as trusted, binding the marker to the |
| 521 | /// current package content digest (schema v2). |
| 522 | /// |
| 523 | /// Refuses to mark system skills (no `.installed-from`) so the bundled |
| 524 | /// `skill-creator` doesn't accidentally inherit elevated tool privileges. |
| 525 | #[cfg(test)] |
| 526 | pub fn trust(name: &str, skills_dir: &Path) -> Result<()> { |
| 527 | let target = skill_target_path(name, skills_dir)?; |
| 528 | if !target.exists() { |
| 529 | bail!("skill '{name}' is not installed at {}", target.display()); |
| 530 | } |
| 531 | ensure_target_within_skills_dir(&target, skills_dir)?; |
| 532 | if !target.join(INSTALLED_FROM_MARKER).exists() { |
| 533 | return Err(InstallError::NotInstalledHere(name.to_string()).into()); |
| 534 | } |
| 535 | let content_digest = super::package_digest::compute_package_digest(&target) |
| 536 | .with_context(|| format!("cannot compute content digest for {}", target.display()))?; |
| 537 | write_trust_v2(&target, &content_digest)?; |
| 538 | Ok(()) |
| 539 | } |
| 540 | |
| 541 | /// Fetch the curated registry and return the parsed entries. |
| 542 | /// |
| 543 | /// Honours `network` (skipping the call entirely on Deny / Prompt). |
| 544 | pub async fn fetch_registry( |
| 545 | network: &NetworkPolicy, |
| 546 | registry_url: &str, |
| 547 | ) -> Result<RegistryFetchResult> { |
| 548 | let host = match host_from_url(registry_url) { |
| 549 | Some(host) => host, |
| 550 | None => bail!("invalid registry url: {registry_url}"), |
| 551 | }; |
| 552 | match network.decide(&host) { |
| 553 | Decision::Allow => {} |
| 554 | Decision::Deny => return Ok(RegistryFetchResult::Denied(host)), |
| 555 | Decision::Prompt => return Ok(RegistryFetchResult::NeedsApproval(host)), |
| 556 | } |
| 557 | let body = reqwest_client() |
| 558 | .get(registry_url) |
| 559 | .send() |
| 560 | .await |
| 561 | .with_context(|| format!("failed to fetch registry {registry_url}"))? |
| 562 | .error_for_status() |
| 563 | .with_context(|| format!("registry {registry_url} returned an error status"))? |
| 564 | .text() |
| 565 | .await |
| 566 | .with_context(|| format!("failed to read registry body from {registry_url}"))?; |
| 567 | let parsed: RegistryDocument = serde_json::from_str(&body) |
| 568 | .with_context(|| format!("failed to parse registry json from {registry_url}"))?; |
| 569 | Ok(RegistryFetchResult::Loaded(parsed)) |
| 570 | } |
| 571 | |
| 572 | // ───────────────────────────────────────────────────────────────────────────── |
| 573 | // Registry sync (issue #433) |
| 574 | // ───────────────────────────────────────────────────────────────────────────── |
| 575 | |
| 576 | /// Outcome of a single skill entry during [`sync_registry`]. |
| 577 | #[derive(Debug, Clone)] |
| 578 | pub enum SkillSyncOutcome { |
| 579 | /// Skill downloaded and written to the cache directory. |
| 580 | Downloaded { name: String, path: PathBuf }, |
| 581 | /// Cached bytes match the upstream ETag / SHA-256; nothing written. |
| 582 | Fresh { name: String }, |
| 583 | /// Skill download failed; the error is non-fatal so the sync continues. |
| 584 | Failed { name: String, reason: String }, |
| 585 | /// Network policy blocked the download host. |
| 586 | Denied { name: String, host: String }, |
| 587 | /// Network policy requires user approval for the download host. |
| 588 | NeedsApproval { name: String, host: String }, |
| 589 | } |
| 590 | |
| 591 | /// Overall result of [`sync_registry`]. |
| 592 | #[derive(Debug)] |
| 593 | pub enum SyncResult { |
| 594 | /// Sync completed. `outcomes` contains one entry per skill in the index. |
| 595 | Done { outcomes: Vec<SkillSyncOutcome> }, |
| 596 | /// The registry fetch was blocked by network policy. |
| 597 | RegistryDenied(String), |
| 598 | /// The registry fetch requires user approval. |
| 599 | RegistryNeedsApproval(String), |
| 600 | } |
| 601 | |
| 602 | /// Freshness metadata written alongside each cached skill so subsequent syncs |
| 603 | /// can skip unchanged content. |
| 604 | #[derive(Debug, Serialize, Deserialize)] |
| 605 | struct CacheMeta { |
| 606 | /// ETag returned by the server for the primary asset, if any. |
| 607 | #[serde(default)] |
| 608 | etag: Option<String>, |
| 609 | /// SHA-256 hex digest of the downloaded bytes. |
| 610 | sha256: String, |
| 611 | /// Source URL the asset was fetched from. |
| 612 | url: String, |
| 613 | } |
| 614 | |
| 615 | /// Sync the remote registry to the local cache. |
| 616 | /// |
| 617 | /// For every skill listed in `index.json` this function: |
| 618 | /// |
| 619 | /// 1. Resolves the download URL (same logic as `install`). |
| 620 | /// 2. Checks the cached [`CacheMeta`] (etag + sha256) for freshness; skips |
| 621 | /// the download if unchanged. |
| 622 | /// 3. Downloads SKILL.md (and any companion files if the source is a tarball) |
| 623 | /// into `<cache_dir>/<name>/`. |
| 624 | /// 4. Writes updated [`CacheMeta`] so the next sync is fast. |
| 625 | /// |
| 626 | /// Failures per-skill are non-fatal: [`SkillSyncOutcome::Failed`] is recorded |
| 627 | /// and the sync continues. The caller decides how to surface per-skill errors. |
| 628 | pub async fn sync_registry( |
| 629 | network: &NetworkPolicy, |
| 630 | registry_url: &str, |
| 631 | cache_dir: &Path, |
| 632 | max_size: u64, |
| 633 | ) -> Result<SyncResult> { |
| 634 | let doc = match fetch_registry(network, registry_url).await? { |
| 635 | RegistryFetchResult::Loaded(doc) => doc, |
| 636 | RegistryFetchResult::Denied(host) => return Ok(SyncResult::RegistryDenied(host)), |
| 637 | RegistryFetchResult::NeedsApproval(host) => { |
| 638 | return Ok(SyncResult::RegistryNeedsApproval(host)); |
| 639 | } |
| 640 | }; |
| 641 | |
| 642 | let outcomes = stream::iter(doc.skills.iter()) |
| 643 | .map(|(name, entry)| sync_one_skill(name, entry, network, cache_dir, max_size)) |
| 644 | .buffered(SYNC_REGISTRY_CONCURRENCY) |
| 645 | .collect() |
| 646 | .await; |
| 647 | |
| 648 | Ok(SyncResult::Done { outcomes }) |
| 649 | } |
| 650 | |
| 651 | /// Sync a single skill entry from the registry into the cache directory. |
| 652 | async fn sync_one_skill( |
| 653 | name: &str, |
| 654 | entry: &RegistryEntry, |
| 655 | network: &NetworkPolicy, |
| 656 | cache_dir: &Path, |
| 657 | max_size: u64, |
| 658 | ) -> SkillSyncOutcome { |
| 659 | // Resolve the source to a concrete URL list. |
| 660 | let source = match InstallSource::parse(&entry.source) { |
| 661 | Ok(s) => s, |
| 662 | Err(err) => { |
| 663 | return SkillSyncOutcome::Failed { |
| 664 | name: name.to_string(), |
| 665 | reason: format!("invalid source spec '{}': {err:#}", entry.source), |
| 666 | }; |
| 667 | } |
| 668 | }; |
| 669 | |
| 670 | // Registry sources in index.json must not point back at another registry. |
| 671 | if matches!(source, InstallSource::Registry(_)) { |
| 672 | return SkillSyncOutcome::Failed { |
| 673 | name: name.to_string(), |
| 674 | reason: format!("registry entry for '{name}' must not point to another registry entry"), |
| 675 | }; |
| 676 | } |
| 677 | |
| 678 | let urls = match &source { |
| 679 | InstallSource::GitHubRepo(repo) => vec![ |
| 680 | format!("https://github.com/{repo}/archive/refs/heads/main.tar.gz"), |
| 681 | format!("https://github.com/{repo}/archive/refs/heads/master.tar.gz"), |
| 682 | ], |
| 683 | InstallSource::DirectUrl(url) => vec![url.clone()], |
| 684 | InstallSource::Registry(_) => unreachable!("guarded above"), |
| 685 | }; |
| 686 | |
| 687 | // Check the first downloadable URL against any cached meta. |
| 688 | let skill_cache_dir = cache_dir.join(name); |
| 689 | let meta_path = skill_cache_dir.join(".cache-meta.json"); |
| 690 | |
| 691 | // Try each candidate URL in order. |
| 692 | for url in &urls { |
| 693 | let host = match host_from_url(url) { |
| 694 | Some(h) => h, |
| 695 | None => continue, |
| 696 | }; |
| 697 | match network.decide(&host) { |
| 698 | Decision::Allow => {} |
| 699 | Decision::Deny => { |
| 700 | return SkillSyncOutcome::Denied { |
| 701 | name: name.to_string(), |
| 702 | host, |
| 703 | }; |
| 704 | } |
| 705 | Decision::Prompt => { |
| 706 | return SkillSyncOutcome::NeedsApproval { |
| 707 | name: name.to_string(), |
| 708 | host, |
| 709 | }; |
| 710 | } |
| 711 | } |
| 712 | |
| 713 | // Perform a HEAD request (or conditional GET) for freshness. We use a |
| 714 | // simple GET with If-None-Match when we have an ETag, falling back to |
| 715 | // an unconditional GET for servers that don't support ETags. |
| 716 | let existing_meta: Option<CacheMeta> = tokio::fs::read_to_string(&meta_path) |
| 717 | .await |
| 718 | .ok() |
| 719 | .and_then(|s| serde_json::from_str(&s).ok()); |
| 720 | |
| 721 | // Build the request — add If-None-Match if we have a cached ETag. |
| 722 | let client = reqwest_client(); |
| 723 | let mut req = client.get(url); |
| 724 | if let Some(ref meta) = existing_meta |
| 725 | && let Some(ref etag) = meta.etag |
| 726 | { |
| 727 | req = req.header("If-None-Match", etag); |
| 728 | } |
| 729 | |
| 730 | let resp = match req.send().await { |
| 731 | Ok(r) => r, |
| 732 | Err(err) => { |
| 733 | // Network error — try the next candidate URL. |
| 734 | let _ = err; |
| 735 | continue; |
| 736 | } |
| 737 | }; |
| 738 | |
| 739 | let status = resp.status(); |
| 740 | |
| 741 | // 304 Not Modified: cached copy is still fresh. |
| 742 | if status == reqwest::StatusCode::NOT_MODIFIED { |
| 743 | return SkillSyncOutcome::Fresh { |
| 744 | name: name.to_string(), |
| 745 | }; |
| 746 | } |
| 747 | |
| 748 | if status == reqwest::StatusCode::NOT_FOUND { |
| 749 | // Try next URL (main → master fallback). |
| 750 | continue; |
| 751 | } |
| 752 | |
| 753 | if !status.is_success() { |
| 754 | return SkillSyncOutcome::Failed { |
| 755 | name: name.to_string(), |
| 756 | reason: format!("GET {url} returned HTTP {status}"), |
| 757 | }; |
| 758 | } |
| 759 | |
| 760 | // Capture ETag before consuming the response body. |
| 761 | let etag = resp |
| 762 | .headers() |
| 763 | .get(reqwest::header::ETAG) |
| 764 | .and_then(|v| v.to_str().ok()) |
| 765 | .map(|s| s.to_string()); |
| 766 | |
| 767 | let compressed_cap = max_size.saturating_mul(4); |
| 768 | let bytes = match resp.bytes().await { |
| 769 | Ok(b) => b, |
| 770 | Err(err) => { |
| 771 | return SkillSyncOutcome::Failed { |
| 772 | name: name.to_string(), |
| 773 | reason: format!("failed to read body from {url}: {err:#}"), |
| 774 | }; |
| 775 | } |
| 776 | }; |
| 777 | if bytes.len() as u64 > compressed_cap { |
| 778 | return SkillSyncOutcome::Failed { |
| 779 | name: name.to_string(), |
| 780 | reason: format!( |
| 781 | "download from {url} exceeds compressed size cap ({compressed_cap} bytes)" |
| 782 | ), |
| 783 | }; |
| 784 | } |
| 785 | |
| 786 | // Compute SHA-256 of the downloaded bytes. |
| 787 | let sha256 = sha256_hex(&bytes); |
| 788 | |
| 789 | // Short-circuit: if the hash matches the cached one, we're fresh even |
| 790 | // without a 304 (some CDNs strip ETags on redirects). |
| 791 | if let Some(ref meta) = existing_meta |
| 792 | && meta.sha256 == sha256 |
| 793 | && meta.url == *url |
| 794 | { |
| 795 | return SkillSyncOutcome::Fresh { |
| 796 | name: name.to_string(), |
| 797 | }; |
| 798 | } |
| 799 | |
| 800 | // Determine whether this is a tarball or a plain SKILL.md. |
| 801 | // Heuristic: the URL ends with `.tar.gz` or `.tgz`, or the content |
| 802 | // starts with the gzip magic bytes (0x1f 0x8b). |
| 803 | let is_tarball = |
| 804 | url.ends_with(".tar.gz") || url.ends_with(".tgz") || bytes.starts_with(&[0x1f, 0x8b]); |
| 805 | |
| 806 | let final_path: PathBuf = if is_tarball { |
| 807 | // Extract into a temp staging dir, then rename atomically. |
| 808 | let staged = match stage_tarball(&bytes, cache_dir, max_size) { |
| 809 | Ok(s) => s, |
| 810 | Err(err) => { |
| 811 | return SkillSyncOutcome::Failed { |
| 812 | name: name.to_string(), |
| 813 | reason: format!("tarball extraction failed: {err:#}"), |
| 814 | }; |
| 815 | } |
| 816 | }; |
| 817 | // Move staged dir into its final location, replacing any prior cache. |
| 818 | let dest = cache_dir.join(name); |
| 819 | if tokio::fs::try_exists(&dest).await.unwrap_or(false) { |
| 820 | let _ = tokio::fs::remove_dir_all(&dest).await; |
| 821 | } |
| 822 | if let Err(err) = tokio::fs::rename(&staged.staged_path, &dest).await { |
| 823 | let _ = tokio::fs::remove_dir_all(&staged.staged_path).await; |
| 824 | return SkillSyncOutcome::Failed { |
| 825 | name: name.to_string(), |
| 826 | reason: format!("failed to move staged skill into cache: {err:#}"), |
| 827 | }; |
| 828 | } |
| 829 | dest |
| 830 | } else { |
| 831 | // Plain SKILL.md (or other companion text file). Write directly. |
| 832 | if let Err(err) = tokio::fs::create_dir_all(&skill_cache_dir).await { |
| 833 | return SkillSyncOutcome::Failed { |
| 834 | name: name.to_string(), |
| 835 | reason: format!("failed to create cache dir: {err:#}"), |
| 836 | }; |
| 837 | } |
| 838 | let skill_md_path = skill_cache_dir.join("SKILL.md"); |
| 839 | if let Err(err) = tokio::fs::write(&skill_md_path, &bytes).await { |
| 840 | return SkillSyncOutcome::Failed { |
| 841 | name: name.to_string(), |
| 842 | reason: format!("failed to write SKILL.md to cache: {err:#}"), |
| 843 | }; |
| 844 | } |
| 845 | skill_cache_dir.clone() |
| 846 | }; |
| 847 | |
| 848 | // Write the updated freshness metadata. |
| 849 | let meta = CacheMeta { |
| 850 | etag, |
| 851 | sha256, |
| 852 | url: url.clone(), |
| 853 | }; |
| 854 | let meta_json = serde_json::to_string(&meta).unwrap_or_default(); |
| 855 | let _ = tokio::fs::write(final_path.join(".cache-meta.json"), meta_json).await; |
| 856 | |
| 857 | return SkillSyncOutcome::Downloaded { |
| 858 | name: name.to_string(), |
| 859 | path: final_path, |
| 860 | }; |
| 861 | } |
| 862 | |
| 863 | // All candidate URLs exhausted without a successful response. |
| 864 | SkillSyncOutcome::Failed { |
| 865 | name: name.to_string(), |
| 866 | reason: format!( |
| 867 | "all candidate URLs for '{}' failed or were not found", |
| 868 | entry.source |
| 869 | ), |
| 870 | } |
| 871 | } |
| 872 | |
| 873 | // ───────────────────────────────────────────────────────────────────────────── |
| 874 | // Internal helpers |
| 875 | // ───────────────────────────────────────────────────────────────────────────── |
| 876 | |
| 877 | #[derive(Debug, Deserialize)] |
| 878 | pub(crate) struct InstalledFromMarker { |
| 879 | pub(crate) spec: String, |
| 880 | /// v1 download checksum field. |
| 881 | #[serde(default)] |
| 882 | checksum: String, |
| 883 | #[serde(default)] |
| 884 | source_checksum: Option<String>, |
| 885 | #[serde(default)] |
| 886 | #[expect(dead_code)] |
| 887 | schema_version: Option<u32>, |
| 888 | #[serde(default)] |
| 889 | #[expect(dead_code)] |
| 890 | content_digest: Option<String>, |
| 891 | } |
| 892 | |
| 893 | impl InstalledFromMarker { |
| 894 | pub(crate) fn source_checksum(&self) -> &str { |
| 895 | self.source_checksum |
| 896 | .as_deref() |
| 897 | .filter(|s| !s.is_empty()) |
| 898 | .unwrap_or(self.checksum.as_str()) |
| 899 | } |
| 900 | } |
| 901 | |
| 902 | /// Remote/registry update is only valid for install specs that are not local imports. |
| 903 | #[must_use] |
| 904 | pub fn is_registry_updatable_spec(spec: &str) -> bool { |
| 905 | let spec = spec.trim(); |
| 906 | !spec.is_empty() && !spec.starts_with("import:") |
| 907 | } |
| 908 | |
| 909 | /// Write schema-v2 `.installed-from` metadata (last step of a successful install). |
| 910 | pub fn write_installed_from_v2( |
| 911 | skill_dir: &Path, |
| 912 | spec: &str, |
| 913 | url: Option<&str>, |
| 914 | source_checksum: &str, |
| 915 | content_digest: &str, |
| 916 | installed_name: &str, |
| 917 | ) -> Result<()> { |
| 918 | let body = serde_json::json!({ |
| 919 | "schema_version": 2, |
| 920 | "spec": spec, |
| 921 | "url": url, |
| 922 | "source_checksum": source_checksum, |
| 923 | "content_digest": content_digest, |
| 924 | "installed_name": installed_name, |
| 925 | "registry_version": null, |
| 926 | }); |
| 927 | fs::write(skill_dir.join(INSTALLED_FROM_MARKER), body.to_string()).with_context(|| { |
| 928 | format!( |
| 929 | "failed to write {} for {}", |
| 930 | INSTALLED_FROM_MARKER, |
| 931 | skill_dir.display() |
| 932 | ) |
| 933 | })?; |
| 934 | Ok(()) |
| 935 | } |
| 936 | |
| 937 | /// Write schema-v2 `.trusted` bound to a package content digest. |
| 938 | pub fn write_trust_v2(skill_dir: &Path, content_digest: &str) -> Result<()> { |
| 939 | let body = serde_json::json!({ |
| 940 | "schema_version": 2, |
| 941 | "content_digest": content_digest, |
| 942 | }); |
| 943 | fs::write(skill_dir.join(TRUSTED_MARKER), body.to_string()).with_context(|| { |
| 944 | format!( |
| 945 | "failed to write {} for {}", |
| 946 | TRUSTED_MARKER, |
| 947 | skill_dir.display() |
| 948 | ) |
| 949 | })?; |
| 950 | Ok(()) |
| 951 | } |
| 952 | |
| 953 | /// Curated-registry document. The shape is intentionally minimal so adding |
| 954 | /// optional metadata later (homepage, version, signature) is forward-compatible. |
| 955 | #[derive(Debug, Clone, Deserialize)] |
| 956 | pub struct RegistryDocument { |
| 957 | /// Map of skill name → entry. |
| 958 | #[serde(default)] |
| 959 | pub skills: std::collections::BTreeMap<String, RegistryEntry>, |
| 960 | } |
| 961 | |
| 962 | /// One row in the curated registry. Descriptive matching metadata is optional |
| 963 | /// so old indices keep parsing and new registries can publish it gradually. |
| 964 | #[derive(Debug, Clone, Deserialize)] |
| 965 | pub struct RegistryEntry { |
| 966 | /// Source spec (e.g. `github:owner/repo`). |
| 967 | pub source: String, |
| 968 | /// Optional human-readable description. |
| 969 | #[serde(default)] |
| 970 | pub description: Option<String>, |
| 971 | /// Task phrases that should rank this skill above description fallbacks. |
| 972 | #[serde(default)] |
| 973 | pub keywords: Vec<String>, |
| 974 | /// Relevant web domains, optionally written as full URLs by the registry. |
| 975 | #[serde(default)] |
| 976 | pub domains: Vec<String>, |
| 977 | } |
| 978 | |
| 979 | /// Successful registry fetch result. Same shape as [`InstallOutcome`] for the |
| 980 | /// network-policy outcomes so the caller can drop directly into approval flow. |
| 981 | #[derive(Debug)] |
| 982 | pub enum RegistryFetchResult { |
| 983 | Loaded(RegistryDocument), |
| 984 | NeedsApproval(String), |
| 985 | Denied(String), |
| 986 | } |
| 987 | |
| 988 | enum UrlResolution { |
| 989 | Resolved(Vec<String>), |
| 990 | NeedsApproval(String), |
| 991 | Denied(String), |
| 992 | } |
| 993 | |
| 994 | enum DownloadOutcome { |
| 995 | Bytes { bytes: Vec<u8>, url: String }, |
| 996 | NeedsApproval(String), |
| 997 | Denied(String), |
| 998 | } |
| 999 | |
| 1000 | /// Outcome of [`fetch_tarball`], shared with the plugin installer (#5182) so |
| 1001 | /// both route `Prompt`/`Deny` hosts through their own approval flows instead |
| 1002 | /// of growing a second download path. |
| 1003 | #[derive(Debug)] |
| 1004 | pub(crate) enum FetchOutcome { |
| 1005 | Bytes { bytes: Vec<u8>, url: String }, |
| 1006 | NeedsApproval(String), |
| 1007 | Denied(String), |
| 1008 | } |
| 1009 | |
| 1010 | /// Resolve a *remote* [`InstallSource`] (GitHub repo or direct tarball URL) |
| 1011 | /// and download the first reachable candidate under the network policy. |
| 1012 | /// Registry sources are rejected: skill registry resolution stays inside |
| 1013 | /// [`candidate_urls`], and the plugin install on-ramp has no registry index. |
| 1014 | pub(crate) async fn fetch_tarball( |
| 1015 | source: &InstallSource, |
| 1016 | network: &NetworkPolicy, |
| 1017 | max_size: u64, |
| 1018 | ) -> Result<FetchOutcome> { |
| 1019 | let urls = match source { |
| 1020 | InstallSource::GitHubRepo(repo) => vec![ |
| 1021 | format!("https://github.com/{repo}/archive/refs/heads/main.tar.gz"), |
| 1022 | format!("https://github.com/{repo}/archive/refs/heads/master.tar.gz"), |
| 1023 | ], |
| 1024 | InstallSource::DirectUrl(url) => vec![url.clone()], |
| 1025 | InstallSource::Registry(name) => { |
| 1026 | bail!("registry source '{name}' cannot be fetched as a plain tarball") |
| 1027 | } |
| 1028 | }; |
| 1029 | Ok( |
| 1030 | match download_first_success(&urls, network, max_size).await? { |
| 1031 | DownloadOutcome::Bytes { bytes, url } => FetchOutcome::Bytes { bytes, url }, |
| 1032 | DownloadOutcome::NeedsApproval(host) => FetchOutcome::NeedsApproval(host), |
| 1033 | DownloadOutcome::Denied(host) => FetchOutcome::Denied(host), |
| 1034 | }, |
| 1035 | ) |
| 1036 | } |
| 1037 | |
| 1038 | /// Resolve the source spec into one or more candidate URLs to try in order. |
| 1039 | async fn candidate_urls( |
| 1040 | source: &InstallSource, |
| 1041 | network: &NetworkPolicy, |
| 1042 | registry_url: &str, |
| 1043 | ) -> Result<UrlResolution> { |
| 1044 | match source { |
| 1045 | InstallSource::GitHubRepo(repo) => { |
| 1046 | // GitHub's archive endpoint lives on `codeload.github.com` after |
| 1047 | // the redirect, but the public URL we hit is `github.com`. Both |
| 1048 | // typically appear in user allow lists; we check the canonical |
| 1049 | // host. |
| 1050 | Ok(UrlResolution::Resolved(vec![ |
| 1051 | format!("https://github.com/{repo}/archive/refs/heads/main.tar.gz"), |
| 1052 | format!("https://github.com/{repo}/archive/refs/heads/master.tar.gz"), |
| 1053 | ])) |
| 1054 | } |
| 1055 | InstallSource::DirectUrl(url) => Ok(UrlResolution::Resolved(vec![url.clone()])), |
| 1056 | InstallSource::Registry(name) => { |
| 1057 | match fetch_registry(network, registry_url).await? { |
| 1058 | RegistryFetchResult::Loaded(doc) => { |
| 1059 | let entry = doc |
| 1060 | .skills |
| 1061 | .get(name) |
| 1062 | .with_context(|| format!("skill '{name}' not found in registry"))? |
| 1063 | .clone(); |
| 1064 | let inner = InstallSource::parse(&entry.source).with_context(|| { |
| 1065 | format!( |
| 1066 | "registry entry for '{name}' has invalid source: {}", |
| 1067 | entry.source |
| 1068 | ) |
| 1069 | })?; |
| 1070 | // Recurse only one level — registry pointing at registry is |
| 1071 | // disallowed to avoid cycles. |
| 1072 | if matches!(inner, InstallSource::Registry(_)) { |
| 1073 | bail!("registry entry for '{name}' must not point to another registry"); |
| 1074 | } |
| 1075 | // Reuse this function for the inner source so GitHub fallback |
| 1076 | // still applies. |
| 1077 | Box::pin(candidate_urls(&inner, network, registry_url)).await |
| 1078 | } |
| 1079 | RegistryFetchResult::NeedsApproval(host) => Ok(UrlResolution::NeedsApproval(host)), |
| 1080 | RegistryFetchResult::Denied(host) => Ok(UrlResolution::Denied(host)), |
| 1081 | } |
| 1082 | } |
| 1083 | } |
| 1084 | } |
| 1085 | |
| 1086 | /// Download the first URL whose host the policy allows and which returns 2xx. |
| 1087 | /// Returns `NeedsApproval` if every candidate hit `Prompt`, or `Denied` if every |
| 1088 | /// candidate was denied. |
| 1089 | async fn download_first_success( |
| 1090 | urls: &[String], |
| 1091 | network: &NetworkPolicy, |
| 1092 | max_size: u64, |
| 1093 | ) -> Result<DownloadOutcome> { |
| 1094 | let mut last_status: Option<reqwest::StatusCode> = None; |
| 1095 | let mut prompt_host: Option<String> = None; |
| 1096 | let mut denied_host: Option<String> = None; |
| 1097 | for url in urls { |
| 1098 | let host = match host_from_url(url) { |
| 1099 | Some(h) => h, |
| 1100 | None => bail!("invalid download url: {url}"), |
| 1101 | }; |
| 1102 | match network.decide(&host) { |
| 1103 | Decision::Allow => {} |
| 1104 | Decision::Deny => { |
| 1105 | denied_host.get_or_insert(host); |
| 1106 | continue; |
| 1107 | } |
| 1108 | Decision::Prompt => { |
| 1109 | prompt_host.get_or_insert(host); |
| 1110 | continue; |
| 1111 | } |
| 1112 | } |
| 1113 | match download_with_cap(url, max_size).await? { |
| 1114 | DownloadAttempt::Bytes(bytes) => { |
| 1115 | return Ok(DownloadOutcome::Bytes { |
| 1116 | bytes, |
| 1117 | url: url.clone(), |
| 1118 | }); |
| 1119 | } |
| 1120 | DownloadAttempt::NotFound(status) => { |
| 1121 | last_status = Some(status); |
| 1122 | continue; |
| 1123 | } |
| 1124 | } |
| 1125 | } |
| 1126 | if let Some(host) = denied_host { |
| 1127 | return Ok(DownloadOutcome::Denied(host)); |
| 1128 | } |
| 1129 | if let Some(host) = prompt_host { |
| 1130 | return Ok(DownloadOutcome::NeedsApproval(host)); |
| 1131 | } |
| 1132 | bail!( |
| 1133 | "failed to download skill (last status: {})", |
| 1134 | last_status |
| 1135 | .map(|s| s.to_string()) |
| 1136 | .unwrap_or_else(|| "unknown".to_string()) |
| 1137 | ); |
| 1138 | } |
| 1139 | |
| 1140 | enum DownloadAttempt { |
| 1141 | Bytes(Vec<u8>), |
| 1142 | NotFound(reqwest::StatusCode), |
| 1143 | } |
| 1144 | |
| 1145 | /// Stream a URL into memory with a size cap. Aborts on the first read that |
| 1146 | /// would push the buffer over `max_size * 4` (the *4 accounts for compression; |
| 1147 | /// the unpack step still enforces `max_size` on the *uncompressed* bytes). |
| 1148 | async fn download_with_cap(url: &str, max_size: u64) -> Result<DownloadAttempt> { |
| 1149 | let resp = reqwest_client() |
| 1150 | .get(url) |
| 1151 | .send() |
| 1152 | .await |
| 1153 | .with_context(|| format!("failed to GET {url}"))?; |
| 1154 | let status = resp.status(); |
| 1155 | if !status.is_success() { |
| 1156 | if status == reqwest::StatusCode::NOT_FOUND { |
| 1157 | return Ok(DownloadAttempt::NotFound(status)); |
| 1158 | } |
| 1159 | bail!("download {url} returned {status}"); |
| 1160 | } |
| 1161 | // Soft cap on the *compressed* download — well above max_size to allow |
| 1162 | // for highly compressible payloads but still bounded. |
| 1163 | let compressed_cap = max_size.saturating_mul(4); |
| 1164 | let bytes = resp |
| 1165 | .bytes() |
| 1166 | .await |
| 1167 | .with_context(|| format!("failed to read body of {url}"))?; |
| 1168 | if (bytes.len() as u64) > compressed_cap { |
| 1169 | bail!("download {url} exceeds compressed size cap of {compressed_cap} bytes"); |
| 1170 | } |
| 1171 | Ok(DownloadAttempt::Bytes(bytes.to_vec())) |
| 1172 | } |
| 1173 | |
| 1174 | struct StagedSkill { |
| 1175 | skill_name: String, |
| 1176 | staged_path: PathBuf, |
| 1177 | } |
| 1178 | |
| 1179 | /// Validate a tarball and extract it into `<skills_dir>/<name>.tmp/`. |
| 1180 | fn stage_tarball(bytes: &[u8], skills_dir: &Path, max_size: u64) -> Result<StagedSkill> { |
| 1181 | fs::create_dir_all(skills_dir) |
| 1182 | .with_context(|| format!("failed to create skills directory {}", skills_dir.display()))?; |
| 1183 | |
| 1184 | // Two passes: first determine the skill name (and therefore the staged |
| 1185 | // dir) by finding the SKILL.md, then extract under that staged dir. |
| 1186 | // Both passes share the same archive bytes; we reset by wrapping fresh |
| 1187 | // decoders. |
| 1188 | |
| 1189 | let scan = scan_tarball(bytes, max_size)?; |
| 1190 | |
| 1191 | // Prepare staged directory. Use a `.tmp` suffix so a crashed install |
| 1192 | // never collides with a real name; remove any leftover from a prior |
| 1193 | // failed attempt. |
| 1194 | let staged_path = skills_dir.join(format!("{}.tmp", scan.skill_name)); |
| 1195 | if staged_path.exists() { |
| 1196 | fs::remove_dir_all(&staged_path).with_context(|| { |
| 1197 | format!( |
| 1198 | "failed to clean stale staging dir {}", |
| 1199 | staged_path.display() |
| 1200 | ) |
| 1201 | })?; |
| 1202 | } |
| 1203 | fs::create_dir_all(&staged_path) |
| 1204 | .with_context(|| format!("failed to create staging dir {}", staged_path.display()))?; |
| 1205 | |
| 1206 | // Second pass — extract. |
| 1207 | let result = extract_into(&scan, bytes, &staged_path, max_size); |
| 1208 | if let Err(err) = result { |
| 1209 | // Cleanup on failure so a half-staged directory doesn't survive. |
| 1210 | let _ = fs::remove_dir_all(&staged_path); |
| 1211 | return Err(err); |
| 1212 | } |
| 1213 | |
| 1214 | Ok(StagedSkill { |
| 1215 | skill_name: scan.skill_name, |
| 1216 | staged_path, |
| 1217 | }) |
| 1218 | } |
| 1219 | |
| 1220 | struct TarballScan { |
| 1221 | /// Skill name from SKILL.md frontmatter. |
| 1222 | skill_name: String, |
| 1223 | /// Archive prefix to strip from each entry (e.g. `repo-main/`). May be empty. |
| 1224 | prefix: String, |
| 1225 | /// Sub-directory inside `prefix` that the SKILL.md lives in (`""` if root, |
| 1226 | /// or `skills/<name>` for repos that bundle multiple skills). |
| 1227 | skill_root: String, |
| 1228 | } |
| 1229 | |
| 1230 | /// First pass: locate SKILL.md, validate frontmatter, compute total size, |
| 1231 | /// reject path-traversal entries and symlinks inside the selected install |
| 1232 | /// subtree. We do not write anything in this pass; that's the second pass's job. |
| 1233 | fn scan_tarball(bytes: &[u8], max_size: u64) -> Result<TarballScan> { |
| 1234 | let cursor = std::io::Cursor::new(bytes); |
| 1235 | let gz = GzDecoder::new(cursor); |
| 1236 | let mut archive = tar::Archive::new(gz); |
| 1237 | |
| 1238 | let mut total_size: u64 = 0; |
| 1239 | let mut prefix: Option<String> = None; |
| 1240 | let mut skill_md_relative: Option<(SkillMdCandidate, Vec<u8>)> = None; |
| 1241 | let mut skill_md_candidate_count: usize = 0; |
| 1242 | let mut has_claude_plugin_manifest = false; |
| 1243 | let mut link_paths: Vec<String> = Vec::new(); |
| 1244 | |
| 1245 | for entry in archive |
| 1246 | .entries() |
| 1247 | .context("failed to read tar entries (corrupt archive?)")? |
| 1248 | { |
| 1249 | let mut entry = entry.context("failed to read tar entry")?; |
| 1250 | let header = entry.header().clone(); |
| 1251 | let entry_type = header.entry_type(); |
| 1252 | let path = entry |
| 1253 | .path() |
| 1254 | .context("tar entry has invalid path")? |
| 1255 | .to_path_buf(); |
| 1256 | let path_str = path.to_string_lossy().into_owned(); |
| 1257 | if !is_safe_path(&path) { |
| 1258 | return Err(InstallError::PathTraversal(path_str).into()); |
| 1259 | } |
| 1260 | if is_claude_plugin_manifest_path(&path) { |
| 1261 | has_claude_plugin_manifest = true; |
| 1262 | } |
| 1263 | |
| 1264 | // Track total size against `max_size` (uncompressed). We honor `header |
| 1265 | // .size` rather than streaming-read every file; tar archives are |
| 1266 | // self-describing so this is reliable for non-malicious inputs and |
| 1267 | // catches the gzip-bomb case. |
| 1268 | if let Ok(size) = header.size() { |
| 1269 | total_size = total_size.saturating_add(size); |
| 1270 | if total_size > max_size { |
| 1271 | return Err(InstallError::OversizedTarball { limit: max_size }.into()); |
| 1272 | } |
| 1273 | } |
| 1274 | |
| 1275 | // Detect prefix from the first entry. GitHub archives wrap everything |
| 1276 | // in `<repo>-<branch>/`; direct tarballs may have no prefix. We treat |
| 1277 | // the first path component as the prefix iff the archive has more than |
| 1278 | // one entry under it, but for SKILL.md detection we just strip the |
| 1279 | // first component if every entry shares it. |
| 1280 | if prefix.is_none() { |
| 1281 | if let Some(Component::Normal(first)) = path.components().next() { |
| 1282 | let candidate = first.to_string_lossy().into_owned(); |
| 1283 | // Only treat the first component as a prefix if it's a |
| 1284 | // directory-like (no extension and the path has more |
| 1285 | // components). Otherwise leave prefix empty. |
| 1286 | if path.components().count() > 1 { |
| 1287 | prefix = Some(candidate); |
| 1288 | } else { |
| 1289 | prefix = Some(String::new()); |
| 1290 | } |
| 1291 | } else { |
| 1292 | prefix = Some(String::new()); |
| 1293 | } |
| 1294 | } |
| 1295 | |
| 1296 | if entry_type.is_symlink() || entry_type.is_hard_link() { |
| 1297 | link_paths.push(path_str); |
| 1298 | continue; |
| 1299 | } |
| 1300 | |
| 1301 | // SKILL.md detection. Match the same workflow layouts that runtime |
| 1302 | // discovery understands: |
| 1303 | // * `<prefix>/SKILL.md` |
| 1304 | // * `<prefix>/*/skills/<name>/SKILL.md` |
| 1305 | // * `<prefix>/<name>/SKILL.md` |
| 1306 | if entry_type.is_file() { |
| 1307 | let stripped = strip_prefix(&path_str, prefix.as_deref().unwrap_or("")); |
| 1308 | if let Some(candidate) = skill_md_candidate(&stripped) { |
| 1309 | skill_md_candidate_count += 1; |
| 1310 | let mut buf = Vec::new(); |
| 1311 | entry |
| 1312 | .read_to_end(&mut buf) |
| 1313 | .context("failed to read SKILL.md from archive")?; |
| 1314 | // Prefer the most explicit match: repo-root SKILL.md first, |
| 1315 | // then known skill-directory layouts, then a single nested |
| 1316 | // `<name>/SKILL.md` repository. |
| 1317 | let replace = skill_md_relative |
| 1318 | .as_ref() |
| 1319 | .is_none_or(|(current, _)| candidate.rank < current.rank); |
| 1320 | if replace { |
| 1321 | skill_md_relative = Some((candidate, buf)); |
| 1322 | } |
| 1323 | } |
| 1324 | } |
| 1325 | } |
| 1326 | |
| 1327 | let prefix = prefix.unwrap_or_default(); |
| 1328 | if has_claude_plugin_manifest && skill_md_candidate_count > 1 { |
| 1329 | return Err(InstallError::ClaudePluginBundle.into()); |
| 1330 | } |
| 1331 | let (skill_md, skill_md_bytes) = skill_md_relative |
| 1332 | .ok_or(InstallError::MissingSkillMd) |
| 1333 | .map_err(anyhow::Error::from)?; |
| 1334 | |
| 1335 | for link_path in link_paths { |
| 1336 | if is_within_selected_root(&link_path, &prefix, &skill_md.skill_root) { |
| 1337 | return Err(InstallError::SymlinkRejected.into()); |
| 1338 | } |
| 1339 | } |
| 1340 | |
| 1341 | // Parse frontmatter to extract the skill name. We reuse the same parser |
| 1342 | // shape as `SkillRegistry::parse_skill` but inline it here so we don't |
| 1343 | // depend on the discovery module's private function. |
| 1344 | let name = parse_frontmatter_name(&skill_md_bytes)?; |
| 1345 | |
| 1346 | Ok(TarballScan { |
| 1347 | skill_name: name, |
| 1348 | prefix, |
| 1349 | skill_root: skill_md.skill_root, |
| 1350 | }) |
| 1351 | } |
| 1352 | |
| 1353 | struct SkillMdCandidate { |
| 1354 | rank: u8, |
| 1355 | skill_root: String, |
| 1356 | } |
| 1357 | |
| 1358 | fn skill_md_candidate(stripped_path: &str) -> Option<SkillMdCandidate> { |
| 1359 | if stripped_path.eq_ignore_ascii_case("SKILL.md") { |
| 1360 | return Some(SkillMdCandidate { |
| 1361 | rank: 0, |
| 1362 | skill_root: String::new(), |
| 1363 | }); |
| 1364 | } |
| 1365 | |
| 1366 | let parts: Vec<&str> = stripped_path.split('/').collect(); |
| 1367 | if parts |
| 1368 | .last() |
| 1369 | .is_none_or(|last| !last.eq_ignore_ascii_case("SKILL.md")) |
| 1370 | { |
| 1371 | return None; |
| 1372 | } |
| 1373 | |
| 1374 | // Common workflow-pack layouts: |
| 1375 | // `skills/<name>/SKILL.md`, `.agents/skills/<name>/SKILL.md`, |
| 1376 | // `.claude/skills/<name>/SKILL.md`, and nested package layouts such as |
| 1377 | // `packages/foo/skills/<name>/SKILL.md`. |
| 1378 | if parts.len() >= 3 { |
| 1379 | let container = parts[parts.len() - 3]; |
| 1380 | let name = parts[parts.len() - 2]; |
| 1381 | if container.eq_ignore_ascii_case("skills") && !name.is_empty() { |
| 1382 | return Some(SkillMdCandidate { |
| 1383 | rank: 1, |
| 1384 | skill_root: parts[..parts.len() - 1].join("/"), |
| 1385 | }); |
| 1386 | } |
| 1387 | } |
| 1388 | |
| 1389 | // Single-skill repos sometimes keep their root tidy with |
| 1390 | // `<skill-name>/SKILL.md` plus sibling docs at repo root. |
| 1391 | if parts.len() == 2 && !parts[0].is_empty() { |
| 1392 | return Some(SkillMdCandidate { |
| 1393 | rank: 2, |
| 1394 | skill_root: parts[0].to_string(), |
| 1395 | }); |
| 1396 | } |
| 1397 | |
| 1398 | None |
| 1399 | } |
| 1400 | |
| 1401 | fn is_claude_plugin_manifest_path(path: &Path) -> bool { |
| 1402 | let parts: Vec<String> = path |
| 1403 | .components() |
| 1404 | .filter_map(|component| match component { |
| 1405 | Component::Normal(part) => Some(part.to_string_lossy().to_string()), |
| 1406 | _ => None, |
| 1407 | }) |
| 1408 | .collect(); |
| 1409 | |
| 1410 | parts.windows(2).any(|window| { |
| 1411 | window[0].eq_ignore_ascii_case(".claude-plugin") |
| 1412 | && window[1].eq_ignore_ascii_case("plugin.json") |
| 1413 | }) |
| 1414 | } |
| 1415 | |
| 1416 | fn extract_into(scan: &TarballScan, bytes: &[u8], dest: &Path, max_size: u64) -> Result<()> { |
| 1417 | let cursor = std::io::Cursor::new(bytes); |
| 1418 | let gz = GzDecoder::new(cursor); |
| 1419 | let mut archive = tar::Archive::new(gz); |
| 1420 | |
| 1421 | let mut total_size: u64 = 0; |
| 1422 | let prefix_with_root = if scan.skill_root.is_empty() { |
| 1423 | scan.prefix.clone() |
| 1424 | } else if scan.prefix.is_empty() { |
| 1425 | scan.skill_root.clone() |
| 1426 | } else { |
| 1427 | format!("{}/{}", scan.prefix, scan.skill_root) |
| 1428 | }; |
| 1429 | |
| 1430 | for entry in archive |
| 1431 | .entries() |
| 1432 | .context("failed to read tar entries (corrupt archive?)")? |
| 1433 | { |
| 1434 | let mut entry = entry.context("failed to read tar entry")?; |
| 1435 | let header = entry.header().clone(); |
| 1436 | let entry_type = header.entry_type(); |
| 1437 | let path = entry |
| 1438 | .path() |
| 1439 | .context("tar entry has invalid path")? |
| 1440 | .to_path_buf(); |
| 1441 | let path_str = path.to_string_lossy().into_owned(); |
| 1442 | if !is_safe_path(&path) { |
| 1443 | return Err(InstallError::PathTraversal(path_str).into()); |
| 1444 | } |
| 1445 | |
| 1446 | // Only extract entries that live under our skill root. For simple |
| 1447 | // tarballs (`SKILL.md` at root) that's everything; for multi-skill |
| 1448 | // repos it's the `skills/<name>/` slice. |
| 1449 | let stripped = strip_prefix(&path_str, &prefix_with_root).into_owned(); |
| 1450 | if stripped.is_empty() && entry_type.is_dir() { |
| 1451 | // The root directory itself — already created. |
| 1452 | continue; |
| 1453 | } |
| 1454 | if stripped == path_str && !prefix_with_root.is_empty() { |
| 1455 | // Nothing to strip => entry is outside our subtree, skip. |
| 1456 | continue; |
| 1457 | } |
| 1458 | // Defense-in-depth: re-validate the stripped path. |
| 1459 | let stripped_path = Path::new(&stripped); |
| 1460 | if !is_safe_path(stripped_path) { |
| 1461 | return Err(InstallError::PathTraversal(stripped).into()); |
| 1462 | } |
| 1463 | if entry_type.is_symlink() || entry_type.is_hard_link() { |
| 1464 | return Err(InstallError::SymlinkRejected.into()); |
| 1465 | } |
| 1466 | |
| 1467 | let target = dest.join(stripped_path); |
| 1468 | // Final paranoia check: ensure the resolved target stays under dest. |
| 1469 | // We can't canonicalize (target doesn't exist yet), so we walk |
| 1470 | // components one more time after composing. |
| 1471 | let target_components: Vec<_> = target.components().collect(); |
| 1472 | let dest_components: Vec<_> = dest.components().collect(); |
| 1473 | if !target_components.starts_with(dest_components.as_slice()) { |
| 1474 | return Err(InstallError::PathTraversal(stripped).into()); |
| 1475 | } |
| 1476 | |
| 1477 | if entry_type.is_dir() { |
| 1478 | fs::create_dir_all(&target) |
| 1479 | .with_context(|| format!("failed to create dir {}", target.display()))?; |
| 1480 | continue; |
| 1481 | } |
| 1482 | if entry_type.is_file() { |
| 1483 | if let Some(parent) = target.parent() { |
| 1484 | fs::create_dir_all(parent) |
| 1485 | .with_context(|| format!("failed to create dir {}", parent.display()))?; |
| 1486 | } |
| 1487 | // Read into a buffer so we can enforce `max_size`. Files inside |
| 1488 | // a SKILL bundle are small; copying through a buffer is fine. |
| 1489 | let mut buf = Vec::new(); |
| 1490 | entry |
| 1491 | .read_to_end(&mut buf) |
| 1492 | .with_context(|| format!("failed to read {}", path.display()))?; |
| 1493 | total_size = total_size.saturating_add(buf.len() as u64); |
| 1494 | if total_size > max_size { |
| 1495 | return Err(InstallError::OversizedTarball { limit: max_size }.into()); |
| 1496 | } |
| 1497 | let mut out = fs::OpenOptions::new() |
| 1498 | .create_new(true) |
| 1499 | .write(true) |
| 1500 | .open(&target) |
| 1501 | .with_context(|| format!("failed to create {}", target.display()))?; |
| 1502 | out.write_all(&buf) |
| 1503 | .with_context(|| format!("failed to write {}", target.display()))?; |
| 1504 | } |
| 1505 | } |
| 1506 | Ok(()) |
| 1507 | } |
| 1508 | |
| 1509 | fn selected_root(prefix: &str, skill_root: &str) -> String { |
| 1510 | if skill_root.is_empty() { |
| 1511 | prefix.to_string() |
| 1512 | } else if prefix.is_empty() { |
| 1513 | skill_root.to_string() |
| 1514 | } else { |
| 1515 | format!("{prefix}/{skill_root}") |
| 1516 | } |
| 1517 | } |
| 1518 | |
| 1519 | fn is_within_selected_root(path: &str, prefix: &str, skill_root: &str) -> bool { |
| 1520 | let root = selected_root(prefix, skill_root); |
| 1521 | if root.is_empty() { |
| 1522 | return true; |
| 1523 | } |
| 1524 | path == root || path.starts_with(&format!("{root}/")) |
| 1525 | } |
| 1526 | |
| 1527 | /// Ensure a tar path has no `..` segments and is not absolute. |
| 1528 | pub(crate) fn is_safe_path(path: &Path) -> bool { |
| 1529 | if path.is_absolute() { |
| 1530 | return false; |
| 1531 | } |
| 1532 | for component in path.components() { |
| 1533 | match component { |
| 1534 | Component::ParentDir => return false, |
| 1535 | Component::Prefix(_) | Component::RootDir => return false, |
| 1536 | _ => {} |
| 1537 | } |
| 1538 | } |
| 1539 | true |
| 1540 | } |
| 1541 | |
| 1542 | fn skill_target_path(name: &str, skills_dir: &Path) -> Result<PathBuf> { |
| 1543 | let name = validate_skill_name_segment(name)?; |
| 1544 | Ok(skills_dir.join(name)) |
| 1545 | } |
| 1546 | |
| 1547 | pub(crate) fn validate_skill_name_segment(name: &str) -> Result<&str> { |
| 1548 | if name.is_empty() || name.trim() != name || name.chars().any(char::is_whitespace) { |
| 1549 | bail!("skill name must be a single path-safe segment (got '{name}')"); |
| 1550 | } |
| 1551 | if name == "." || name == ".." || name.contains('/') || name.contains('\\') { |
| 1552 | bail!("skill name must be a single path-safe segment (got '{name}')"); |
| 1553 | } |
| 1554 | let mut components = Path::new(name).components(); |
| 1555 | if !matches!(components.next(), Some(Component::Normal(_))) || components.next().is_some() { |
| 1556 | bail!("skill name must be a single path-safe segment (got '{name}')"); |
| 1557 | } |
| 1558 | Ok(name) |
| 1559 | } |
| 1560 | |
| 1561 | fn ensure_target_within_skills_dir(target: &Path, skills_dir: &Path) -> Result<()> { |
| 1562 | let skills_dir = fs::canonicalize(skills_dir) |
| 1563 | .with_context(|| format!("failed to resolve {}", skills_dir.display()))?; |
| 1564 | let target = fs::canonicalize(target) |
| 1565 | .with_context(|| format!("failed to resolve {}", target.display()))?; |
| 1566 | if !target.starts_with(&skills_dir) { |
| 1567 | bail!( |
| 1568 | "skill path {} escapes skills directory {}", |
| 1569 | target.display(), |
| 1570 | skills_dir.display() |
| 1571 | ); |
| 1572 | } |
| 1573 | Ok(()) |
| 1574 | } |
| 1575 | |
| 1576 | /// Strip a leading directory prefix (e.g. `repo-main/`) from a tarball path. |
| 1577 | fn strip_prefix<'a>(path: &'a str, prefix: &str) -> std::borrow::Cow<'a, str> { |
| 1578 | if prefix.is_empty() { |
| 1579 | return std::borrow::Cow::Borrowed(path); |
| 1580 | } |
| 1581 | let with_slash = format!("{prefix}/"); |
| 1582 | if let Some(rest) = path.strip_prefix(&with_slash) { |
| 1583 | std::borrow::Cow::Owned(rest.to_string()) |
| 1584 | } else if path == prefix { |
| 1585 | std::borrow::Cow::Borrowed("") |
| 1586 | } else { |
| 1587 | std::borrow::Cow::Borrowed(path) |
| 1588 | } |
| 1589 | } |
| 1590 | |
| 1591 | /// Extract `name:` and ensure `description:` exist in the SKILL.md frontmatter. |
| 1592 | /// Also verifies the leading `---` fence so we reject malformed files early. |
| 1593 | fn parse_frontmatter_name(bytes: &[u8]) -> Result<String> { |
| 1594 | let content = std::str::from_utf8(bytes).context("SKILL.md is not valid UTF-8")?; |
| 1595 | let trimmed = content.trim_start(); |
| 1596 | if !trimmed.starts_with("---") { |
| 1597 | bail!("SKILL.md is missing the leading '---' frontmatter fence"); |
| 1598 | } |
| 1599 | let after_open = &trimmed[3..]; |
| 1600 | let close = after_open.find("---").ok_or_else(|| { |
| 1601 | anyhow::anyhow!("SKILL.md is missing the closing '---' frontmatter fence") |
| 1602 | })?; |
| 1603 | let frontmatter = &after_open[..close]; |
| 1604 | |
| 1605 | let mut name: Option<String> = None; |
| 1606 | let mut has_description = false; |
| 1607 | for raw in frontmatter.lines() { |
| 1608 | let line = raw.trim(); |
| 1609 | if line.is_empty() || line.starts_with('#') { |
| 1610 | continue; |
| 1611 | } |
| 1612 | if let Some((key, value)) = line.split_once(':') { |
| 1613 | let key = key.trim().to_ascii_lowercase(); |
| 1614 | let value = value.trim().to_string(); |
| 1615 | match key.as_str() { |
| 1616 | "name" if !value.is_empty() => name = Some(value), |
| 1617 | "description" if !value.is_empty() => has_description = true, |
| 1618 | _ => {} |
| 1619 | } |
| 1620 | } |
| 1621 | } |
| 1622 | |
| 1623 | let name = name.ok_or(InstallError::MissingFrontmatterField("name"))?; |
| 1624 | if !has_description { |
| 1625 | return Err(InstallError::MissingFrontmatterField("description").into()); |
| 1626 | } |
| 1627 | if validate_skill_name_segment(&name).is_err() { |
| 1628 | bail!("SKILL.md `name` must be a single path-safe segment (got '{name}')"); |
| 1629 | } |
| 1630 | Ok(name) |
| 1631 | } |
| 1632 | |
| 1633 | fn reject_unmarked_update(final_path: &Path, name: &str) -> std::result::Result<(), InstallError> { |
| 1634 | if final_path.join(INSTALLED_FROM_MARKER).exists() { |
| 1635 | Ok(()) |
| 1636 | } else { |
| 1637 | Err(InstallError::NotInstalledHere(name.to_string())) |
| 1638 | } |
| 1639 | } |
| 1640 | |
| 1641 | pub(crate) fn source_spec_string(source: &InstallSource) -> String { |
| 1642 | match source { |
| 1643 | InstallSource::GitHubRepo(repo) => format!("github:{repo}"), |
| 1644 | InstallSource::DirectUrl(url) => url.clone(), |
| 1645 | InstallSource::Registry(name) => name.clone(), |
| 1646 | } |
| 1647 | } |
| 1648 | |
| 1649 | pub(crate) fn sha256_hex(bytes: &[u8]) -> String { |
| 1650 | hex_bytes(Sha256::digest(bytes)) |
| 1651 | } |
| 1652 | |
| 1653 | fn hex_bytes(bytes: impl AsRef<[u8]>) -> String { |
| 1654 | let bytes = bytes.as_ref(); |
| 1655 | let mut out = String::with_capacity(bytes.len() * 2); |
| 1656 | for byte in bytes { |
| 1657 | use std::fmt::Write as _; |
| 1658 | let _ = write!(&mut out, "{byte:02x}"); |
| 1659 | } |
| 1660 | out |
| 1661 | } |
| 1662 | |
| 1663 | // ───────────────────────────────────────────────────────────────────────────── |
| 1664 | // Tests |
| 1665 | // ───────────────────────────────────────────────────────────────────────────── |
| 1666 | |
| 1667 | #[cfg(test)] |
| 1668 | mod tests { |
| 1669 | use super::*; |
| 1670 | |
| 1671 | #[test] |
| 1672 | fn parse_github_source() { |
| 1673 | let s = InstallSource::parse("github:Hmbown/test-skill").unwrap(); |
| 1674 | assert_eq!( |
| 1675 | s, |
| 1676 | InstallSource::GitHubRepo("Hmbown/test-skill".to_string()) |
| 1677 | ); |
| 1678 | } |
| 1679 | |
| 1680 | #[test] |
| 1681 | fn parse_github_source_rejects_missing_repo() { |
| 1682 | let err = InstallSource::parse("github:Hmbown").unwrap_err(); |
| 1683 | assert!(err.to_string().contains("github source must"), "got: {err}"); |
| 1684 | } |
| 1685 | |
| 1686 | #[test] |
| 1687 | fn parse_github_source_rejects_extra_slashes() { |
| 1688 | let err = InstallSource::parse("github:Hmbown/repo/extra").unwrap_err(); |
| 1689 | assert!(err.to_string().contains("github source must"), "got: {err}"); |
| 1690 | } |
| 1691 | |
| 1692 | #[test] |
| 1693 | fn parse_direct_url_source() { |
| 1694 | let s = InstallSource::parse("https://example.com/skill.tar.gz").unwrap(); |
| 1695 | assert_eq!( |
| 1696 | s, |
| 1697 | InstallSource::DirectUrl("https://example.com/skill.tar.gz".to_string()) |
| 1698 | ); |
| 1699 | let s = InstallSource::parse("http://example.com/skill.tar.gz").unwrap(); |
| 1700 | assert_eq!( |
| 1701 | s, |
| 1702 | InstallSource::DirectUrl("http://example.com/skill.tar.gz".to_string()) |
| 1703 | ); |
| 1704 | } |
| 1705 | |
| 1706 | #[test] |
| 1707 | fn parse_github_browser_url_routes_to_github_repo() { |
| 1708 | // Regression for #269: `https://github.com/<owner>/<repo>` was being |
| 1709 | // parsed as a DirectUrl, so the installer downloaded the HTML repo |
| 1710 | // page and tried to gzip-decode HTML ("invalid gzip header"). |
| 1711 | for spec in [ |
| 1712 | "https://github.com/obra/superpowers", |
| 1713 | "https://github.com/obra/superpowers/", |
| 1714 | "https://github.com/obra/superpowers.git", |
| 1715 | "https://github.com/obra/superpowers.git/", |
| 1716 | "https://www.github.com/obra/superpowers", |
| 1717 | "http://github.com/obra/superpowers", |
| 1718 | " https://github.com/obra/superpowers ", |
| 1719 | ] { |
| 1720 | let parsed = InstallSource::parse(spec) |
| 1721 | .unwrap_or_else(|err| panic!("parse({spec}) failed: {err}")); |
| 1722 | assert_eq!( |
| 1723 | parsed, |
| 1724 | InstallSource::GitHubRepo("obra/superpowers".to_string()), |
| 1725 | "spec {spec} must route to GitHubRepo", |
| 1726 | ); |
| 1727 | } |
| 1728 | } |
| 1729 | |
| 1730 | #[test] |
| 1731 | fn parse_github_archive_url_stays_direct() { |
| 1732 | // URLs that point at a specific subresource (archive tarball, blob, |
| 1733 | // tree) are real direct URLs — the user picked that exact path. |
| 1734 | for spec in [ |
| 1735 | "https://github.com/obra/superpowers/archive/refs/heads/main.tar.gz", |
| 1736 | "https://github.com/obra/superpowers/blob/main/README.md", |
| 1737 | "https://github.com/obra/superpowers/tree/main", |
| 1738 | ] { |
| 1739 | let parsed = InstallSource::parse(spec).unwrap(); |
| 1740 | assert!( |
| 1741 | matches!(parsed, InstallSource::DirectUrl(_)), |
| 1742 | "spec {spec} must stay DirectUrl, got {parsed:?}", |
| 1743 | ); |
| 1744 | } |
| 1745 | } |
| 1746 | |
| 1747 | #[test] |
| 1748 | fn parse_registry_source() { |
| 1749 | let s = InstallSource::parse("my-skill").unwrap(); |
| 1750 | assert_eq!(s, InstallSource::Registry("my-skill".to_string())); |
| 1751 | } |
| 1752 | |
| 1753 | #[test] |
| 1754 | fn parse_rejects_empty() { |
| 1755 | assert!(InstallSource::parse("").is_err()); |
| 1756 | assert!(InstallSource::parse(" ").is_err()); |
| 1757 | } |
| 1758 | |
| 1759 | #[test] |
| 1760 | fn is_safe_path_rejects_traversal() { |
| 1761 | assert!(!is_safe_path(Path::new("../etc/passwd"))); |
| 1762 | assert!(!is_safe_path(Path::new("foo/../bar"))); |
| 1763 | assert!(!is_safe_path(Path::new("/etc/passwd"))); |
| 1764 | assert!(is_safe_path(Path::new("foo/bar/baz"))); |
| 1765 | assert!(is_safe_path(Path::new("SKILL.md"))); |
| 1766 | } |
| 1767 | |
| 1768 | #[test] |
| 1769 | fn parse_frontmatter_extracts_name() { |
| 1770 | let body = b"---\nname: hello\ndescription: greeter\n---\nbody\n"; |
| 1771 | assert_eq!(parse_frontmatter_name(body).unwrap(), "hello"); |
| 1772 | } |
| 1773 | |
| 1774 | #[test] |
| 1775 | fn parse_frontmatter_missing_name_fails() { |
| 1776 | let body = b"---\ndescription: x\n---\n"; |
| 1777 | let err = parse_frontmatter_name(body).unwrap_err(); |
| 1778 | assert!(format!("{err}").contains("name")); |
| 1779 | } |
| 1780 | |
| 1781 | #[test] |
| 1782 | fn parse_frontmatter_missing_description_fails() { |
| 1783 | let body = b"---\nname: x\n---\n"; |
| 1784 | let err = parse_frontmatter_name(body).unwrap_err(); |
| 1785 | assert!(format!("{err}").contains("description")); |
| 1786 | } |
| 1787 | |
| 1788 | #[test] |
| 1789 | fn parse_frontmatter_rejects_unsafe_name() { |
| 1790 | let body = b"---\nname: ../evil\ndescription: x\n---\n"; |
| 1791 | assert!(parse_frontmatter_name(body).is_err()); |
| 1792 | |
| 1793 | let body = b"---\nname: a name with spaces\ndescription: x\n---\n"; |
| 1794 | assert!(parse_frontmatter_name(body).is_err()); |
| 1795 | |
| 1796 | let body = b"---\nname: tab\tname\ndescription: x\n---\n"; |
| 1797 | assert!(parse_frontmatter_name(body).is_err()); |
| 1798 | } |
| 1799 | |
| 1800 | #[test] |
| 1801 | fn parse_frontmatter_requires_opening_fence() { |
| 1802 | let body = b"name: hello\ndescription: x\n"; |
| 1803 | assert!(parse_frontmatter_name(body).is_err()); |
| 1804 | } |
| 1805 | |
| 1806 | #[test] |
| 1807 | fn update_refuses_to_replace_a_directory_without_an_install_marker() { |
| 1808 | let tmp = tempfile::tempdir().expect("tempdir"); |
| 1809 | let dest = tmp.path().join("hand-authored"); |
| 1810 | std::fs::create_dir_all(&dest).expect("dest"); |
| 1811 | std::fs::write(dest.join("SKILL.md"), "---\nname: hand-authored\n---\n").expect("skill md"); |
| 1812 | assert!(!dest.join(INSTALLED_FROM_MARKER).exists()); |
| 1813 | let err = reject_unmarked_update(&dest, "hand-authored").unwrap_err(); |
| 1814 | assert!(matches!(err, InstallError::NotInstalledHere(name) if name == "hand-authored")); |
| 1815 | assert!(dest.join("SKILL.md").exists(), "unmarked tree must survive"); |
| 1816 | } |
| 1817 | |
| 1818 | #[test] |
| 1819 | fn user_skill_names_must_be_single_safe_segments() { |
| 1820 | for bad in [ |
| 1821 | "", |
| 1822 | "../evil", |
| 1823 | "/tmp/evil", |
| 1824 | "two words", |
| 1825 | "two\twords", |
| 1826 | "evil/name", |
| 1827 | "evil\\name", |
| 1828 | ".", |
| 1829 | "..", |
| 1830 | " leading", |
| 1831 | "trailing ", |
| 1832 | ] { |
| 1833 | assert!( |
| 1834 | validate_skill_name_segment(bad).is_err(), |
| 1835 | "expected {bad:?} to be rejected" |
| 1836 | ); |
| 1837 | } |
| 1838 | assert_eq!( |
| 1839 | validate_skill_name_segment("safe-name_1").unwrap(), |
| 1840 | "safe-name_1" |
| 1841 | ); |
| 1842 | } |
| 1843 | |
| 1844 | #[test] |
| 1845 | fn uninstall_and_trust_reject_unsafe_skill_names_before_path_join() { |
| 1846 | let tmp = tempfile::tempdir().expect("tempdir"); |
| 1847 | let skills_dir = tmp.path().join("skills"); |
| 1848 | std::fs::create_dir_all(&skills_dir).expect("skills dir"); |
| 1849 | |
| 1850 | for bad in [ |
| 1851 | "../evil", |
| 1852 | "/tmp/evil", |
| 1853 | "evil/name", |
| 1854 | "evil\\name", |
| 1855 | "two words", |
| 1856 | ] { |
| 1857 | assert!(uninstall(bad, &skills_dir).is_err()); |
| 1858 | assert!(trust(bad, &skills_dir).is_err()); |
| 1859 | } |
| 1860 | } |
| 1861 | |
| 1862 | #[cfg(unix)] |
| 1863 | #[test] |
| 1864 | fn uninstall_rejects_symlink_target_escaping_skills_dir() { |
| 1865 | let tmp = tempfile::tempdir().expect("tempdir"); |
| 1866 | let skills_dir = tmp.path().join("skills"); |
| 1867 | let outside = tmp.path().join("outside"); |
| 1868 | std::fs::create_dir_all(&skills_dir).expect("skills dir"); |
| 1869 | std::fs::create_dir_all(&outside).expect("outside dir"); |
| 1870 | std::fs::write(outside.join(INSTALLED_FROM_MARKER), "{}").expect("marker"); |
| 1871 | std::os::unix::fs::symlink(&outside, skills_dir.join("linked")).expect("symlink"); |
| 1872 | |
| 1873 | let err = uninstall("linked", &skills_dir).unwrap_err(); |
| 1874 | assert!(err.to_string().contains("escapes skills directory")); |
| 1875 | assert!(outside.exists()); |
| 1876 | } |
| 1877 | |
| 1878 | #[test] |
| 1879 | fn strip_prefix_handles_all_cases() { |
| 1880 | assert_eq!(strip_prefix("foo/bar", "foo"), "bar"); |
| 1881 | assert_eq!(strip_prefix("foo", "foo"), ""); |
| 1882 | assert_eq!(strip_prefix("baz/bar", "foo"), "baz/bar"); |
| 1883 | assert_eq!(strip_prefix("foo/bar", ""), "foo/bar"); |
| 1884 | } |
| 1885 | |
| 1886 | #[test] |
| 1887 | fn source_spec_string_roundtrips() { |
| 1888 | assert_eq!( |
| 1889 | source_spec_string(&InstallSource::GitHubRepo("a/b".into())), |
| 1890 | "github:a/b" |
| 1891 | ); |
| 1892 | assert_eq!( |
| 1893 | source_spec_string(&InstallSource::DirectUrl("https://x".into())), |
| 1894 | "https://x" |
| 1895 | ); |
| 1896 | assert_eq!( |
| 1897 | source_spec_string(&InstallSource::Registry("x".into())), |
| 1898 | "x" |
| 1899 | ); |
| 1900 | } |
| 1901 | } |
| 1902 |