Add GitHub plugin release imports and update discovery

2026-09-18 01:29:38 -04:00
parent a718efc9e7
commit 3c49437bf9
16 changed files with 847 additions and 2 deletions
@@ -0,0 +1,140 @@
+import { createHash } from 'node:crypto';
+import type { GithubPluginAsset, GithubPluginRelease } from '$lib/plugin-github.js';
+
+const MAX_DLL_BYTES = 64 * 1024 * 1024;
+const CACHE_MS = 5 * 60 * 1000;
+const cache = new Map<string, { expires: number; release: Promise<GithubPluginRelease> }>();
+
+export class GithubReleaseError extends Error {
+    constructor(message: string, public readonly status = 400) { super(message); }
+}
+
+export function parseGithubReleaseUrl(input: string): { repository: string; tag: string | null } {
+    let url: URL;
+    try { url = new URL(input); } catch { throw new GithubReleaseError('Enter a GitHub repository or release URL.'); }
+    if (url.protocol !== 'https:' || url.hostname !== 'github.com' || url.port || url.username || url.password || url.search) {
+        throw new GithubReleaseError('Use an https://github.com repository or release URL.');
+    }
+    const match = /^\/([\w-]+)\/([\w.-]+)(?:\/(.*?))?\/?$/.exec(url.pathname);
+    if (!match || match[2] === '.' || match[2] === '..') throw new GithubReleaseError('Invalid GitHub repository URL.');
+    const repository = `${match[1]}/${match[2]}`;
+    const path = (match[3] ?? '').replace(/\/$/, '');
+    let tag: string | null = null;
+    try {
+        if (path.startsWith('releases/tag/')) tag = decodeURIComponent(path.slice(13));
+        else if (path === 'releases' && url.hash.startsWith('#release-')) tag = decodeURIComponent(url.hash.slice(9));
+        else if (!['', 'releases', 'releases/latest'].includes(path) || url.hash) throw new Error();
+    } catch { throw new GithubReleaseError('Use a repository URL or a link to a specific GitHub release.'); }
+    if (tag !== null && (!tag || tag.length > 80 || /[\u0000-\u001f\u007f]/.test(tag))) {
+        throw new GithubReleaseError('Release tags must contain 1–80 characters on one line.');
+    }
+    return { repository, tag };
+}
+
+function safeAssetName(name: unknown): name is string {
+    return typeof name === 'string' && /^[^<>:"/\\|?*\u0000-\u001f]+\.dll$/i.test(name) && name.length <= 200;
+}
+
+async function limitedBody(response: Response, limit: number): Promise<Buffer> {
+    if (Number(response.headers.get('content-length')) > limit) {
+        await response.body?.cancel();
+        throw new GithubReleaseError('GitHub response exceeds the download size limit.', 502);
+    }
+    if (!response.body) throw new GithubReleaseError('GitHub returned an empty response.', 502);
+    const reader = response.body.getReader();
+    const chunks: Uint8Array[] = [];
+    let size = 0;
+    try {
+        for (;;) {
+            const next = await reader.read();
+            if (next.done) break;
+            size += next.value.byteLength;
+            if (size > limit) throw new GithubReleaseError('GitHub response exceeds the download size limit.', 502);
+            chunks.push(next.value);
+        }
+    } finally { await reader.cancel(); }
+    return Buffer.concat(chunks);
+}
+
+async function fetchRelease(repository: string, tag: string | null): Promise<GithubPluginRelease> {
+    const suffix = tag === null ? 'latest' : `tags/${encodeURIComponent(tag)}`;
+    try {
+        const response = await fetch(`https://api.github.com/repos/${repository}/releases/${suffix}`, {
+            headers: { Accept: 'application/vnd.github+json', 'User-Agent': 'Electric-Cherry', 'X-GitHub-Api-Version': '2022-11-28' },
+            signal: AbortSignal.timeout(15_000), redirect: 'error'
+        });
+        if (!response.ok) {
+            await response.body?.cancel();
+            if (response.status === 404) throw new GithubReleaseError('No published release found. Check the repository and tag; only public repositories are supported.', 404);
+            if ([403, 429].includes(response.status)) throw new GithubReleaseError('GitHub is limiting requests. Try checking again later.', 429);
+            throw new GithubReleaseError(`GitHub could not load this release (HTTP ${response.status}).`, 502);
+        }
+        const data = JSON.parse((await limitedBody(response, 2 * 1024 * 1024)).toString('utf8'));
+        if (!Number.isSafeInteger(data.id) || data.id < 1 || data.draft || typeof data.tag_name !== 'string' ||
+            !data.tag_name.trim() || data.tag_name.length > 80 || /[\u0000-\u001f\u007f]/.test(data.tag_name) ||
+            !Number.isFinite(Date.parse(data.published_at)) || !Array.isArray(data.assets)) {
+            throw new GithubReleaseError('GitHub returned invalid release metadata.', 502);
+        }
+        return {
+            repository, id: data.id, tag: data.tag_name,
+            url: `https://github.com/${repository}/releases/tag/${encodeURIComponent(data.tag_name)}`,
+            name: typeof data.name === 'string' ? data.name : data.tag_name,
+            notes: typeof data.body === 'string' ? data.body : '', publishedAt: data.published_at,
+            prerelease: data.prerelease === true,
+            assets: data.assets.filter((a: any) => a && Number.isSafeInteger(a.id) && a.id > 0 && safeAssetName(a.name) &&
+                a.state === 'uploaded' && Number.isSafeInteger(a.size) && a.size > 0 && a.size <= MAX_DLL_BYTES)
+                .map((a: any) => ({ id: a.id, name: a.name, size: a.size, digest: typeof a.digest === 'string' ? a.digest : null }))
+        };
+    } catch (error) {
+        if (error instanceof GithubReleaseError) throw error;
+        throw new GithubReleaseError('Could not reach GitHub or read the release. Try again shortly.', 502);
+    }
+}
+
+export async function getGithubRelease(url: string, fresh = false): Promise<GithubPluginRelease> {
+    const { repository, tag } = parseGithubReleaseUrl(url);
+    const key = `${repository.toLowerCase()}:${tag ?? '<latest>'}`;
+    const hit = cache.get(key);
+    if (!fresh && hit && hit.expires > Date.now()) return hit.release;
+    if (cache.size >= 100) cache.delete(cache.keys().next().value!);
+    const release = fetchRelease(repository, tag);
+    cache.set(key, { expires: Date.now() + CACHE_MS, release });
+    try { return await release; } catch (error) { cache.delete(key); throw error; }
+}
+
+export async function downloadGithubAsset(release: GithubPluginRelease, asset: GithubPluginAsset): Promise<Buffer> {
+    // Construct the URL from validated metadata. Never fetch a client-supplied download URL.
+    let url = new URL(`https://github.com/${release.repository}/releases/download/${encodeURIComponent(release.tag)}/${encodeURIComponent(asset.name)}`);
+    const signal = AbortSignal.timeout(60_000);
+    try {
+        for (let i = 0; i < 5; i++) {
+            if (url.protocol !== 'https:' || url.port || url.username || url.password ||
+                !['github.com', 'release-assets.githubusercontent.com', 'objects.githubusercontent.com'].includes(url.hostname)) {
+                throw new GithubReleaseError('GitHub redirected this download to an unsupported host.', 502);
+            }
+            const response = await fetch(url, { redirect: 'manual', signal, headers: { 'User-Agent': 'Electric-Cherry' } });
+            if ([301, 302, 303, 307, 308].includes(response.status)) {
+                await response.body?.cancel();
+                const location = response.headers.get('location');
+                if (!location) break;
+                url = new URL(location, url);
+                continue;
+            }
+            if (!response.ok) {
+                await response.body?.cancel();
+                throw new GithubReleaseError(`GitHub asset download failed (HTTP ${response.status}).`, 502);
+            }
+            const content = await limitedBody(response, MAX_DLL_BYTES);
+            if (content.length !== asset.size) throw new GithubReleaseError('Downloaded size differs from the release asset. Preview the release again.', 502);
+            const sha = createHash('sha256').update(content).digest('hex');
+            if (asset.digest?.startsWith('sha256:') && asset.digest.toLowerCase() !== `sha256:${sha}`) {
+                throw new GithubReleaseError('Downloaded checksum does not match GitHub’s asset digest.', 502);
+            }
+            return content;
+        }
+        throw new GithubReleaseError('GitHub asset download redirected too many times.', 502);
+    } catch (error) {
+        if (error instanceof GithubReleaseError) throw error;
+        throw new GithubReleaseError('Could not download the DLL from GitHub. Try again shortly.', 502);
+    }
+}