marcieandorch-01
736b0affc1
ci/woodpecker/push/publish Pipeline was successful
Co-authored-by: marcie <[email protected]>
75 lines
2.6 KiB
TypeScript
75 lines
2.6 KiB
TypeScript
import path from 'node:path';
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import fs from 'node:fs';
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function isContained(candidate: string, root: string): boolean {
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return candidate === root || candidate.startsWith(root + path.sep);
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}
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function assertLexicalContainment(userPath: string, sandboxDir: string): string {
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const resolved = path.resolve(sandboxDir, userPath);
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const sandboxAbsolute = path.resolve(sandboxDir);
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if (!isContained(resolved, sandboxAbsolute)) {
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throw new SandboxEscapeError(userPath, sandboxDir, resolved);
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}
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return resolved;
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}
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/**
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* Resolve an existing path and verify both its lexical path and real symlink
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* target remain inside the sandbox.
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*/
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export function guardPath(userPath: string, sandboxDir: string): string {
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const resolved = assertLexicalContainment(userPath, sandboxDir);
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const sandboxReal = fs.realpathSync.native(sandboxDir);
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const resolvedReal = fs.realpathSync.native(resolved);
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if (!isContained(resolvedReal, sandboxReal)) {
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throw new SandboxEscapeError(userPath, sandboxDir, resolvedReal);
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}
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return resolvedReal;
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}
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/**
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* Resolve a writable file path whose parent already exists. Existing targets
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* are resolved fully. New targets use the real parent directory, which blocks
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* writes through a parent symlink that leaves the sandbox.
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*/
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export function guardWritePath(userPath: string, sandboxDir: string): string {
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const resolved = assertLexicalContainment(userPath, sandboxDir);
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const sandboxReal = fs.realpathSync.native(sandboxDir);
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let writableReal: string;
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try {
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writableReal = fs.realpathSync.native(resolved);
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} catch (error) {
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const code = (error as NodeJS.ErrnoException).code;
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if (code !== 'ENOENT') throw error;
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const parentReal = fs.realpathSync.native(path.dirname(resolved));
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writableReal = path.join(parentReal, path.basename(resolved));
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}
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if (!isContained(writableReal, sandboxReal)) {
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throw new SandboxEscapeError(userPath, sandboxDir, writableReal);
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}
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return writableReal;
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}
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/**
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* Lexical-only validation for non-filesystem pathspecs such as `git diff --`
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* targets, where the path may name a deleted file and Git does not dereference
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* a tracked symlink.
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*/
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export function guardPathUnsafe(userPath: string, sandboxDir: string): string {
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return assertLexicalContainment(userPath, sandboxDir);
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}
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export class SandboxEscapeError extends Error {
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constructor(
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public readonly userPath: string,
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public readonly sandboxDir: string,
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public readonly resolvedPath: string,
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) {
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super(
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`Path escape attempt blocked: "${userPath}" resolves to "${resolvedPath}" which is outside sandbox "${sandboxDir}"`,
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);
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this.name = 'SandboxEscapeError';
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}
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}
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