PaddedCell/plugin/tools/pcexec.ts

import { spawn, SpawnOptions } from 'child_process';

export interface PcExecOptions {
  /** Current working directory */
  cwd?: string;
  /** Environment variables */
  env?: Record<string, string>;
  /** Timeout in milliseconds */
  timeout?: number;
  /** Maximum buffer size for stdout/stderr */
  maxBuffer?: number;
  /** Kill signal */
  killSignal?: NodeJS.Signals;
  /** Shell to use */
  shell?: string | boolean;
  /** UID to run as */
  uid?: number;
  /** GID to run as */
  gid?: number;
  /** Window style (Windows only) */
  windowsHide?: boolean;
}

export interface PcExecResult {
  /** Standard output */
  stdout: string;
  /** Standard error */
  stderr: string;
  /** Exit code */
  exitCode: number;
  /** Command that was executed */
  command: string;
}

export interface PcExecError extends Error {
  /** Exit code */
  code?: number;
  /** Signal that terminated the process */
  signal?: string;
  /** Standard output */
  stdout: string;
  /** Standard error */
  stderr: string;
  /** Killed by timeout */
  killed?: boolean;
}

/**
 * Extract pass_mgr invocations from a command string.
 *
 * Supports both legacy and new formats:
 *   Legacy:  $(pass_mgr get <key>)  /  `pass_mgr get <key>`
 *   New:     $(pass_mgr get-secret --key <key>)  /  `pass_mgr get-secret --key <key>`
 *
 * Returns array of { fullMatch, subcommand, key } where subcommand is
 * "get" | "get-secret".
 */
function extractPassMgrGets(
  command: string,
): Array<{ key: string; fullMatch: string; subcommand: string }> {
  const results: Array<{ key: string; fullMatch: string; subcommand: string }> = [];
  const seen = new Set<string>();

  // New format: pass_mgr get-secret --key <key>
  const newPatterns = [
    /\$\(\s*pass_mgr\s+get-secret\s+--key\s+(\S+)\s*\)/g,
    /`\s*pass_mgr\s+get-secret\s+--key\s+(\S+)\s*`/g,
  ];

  // Legacy format: pass_mgr get <key>
  const legacyPatterns = [
    /\$\(\s*pass_mgr\s+get\s+(\S+)\s*\)/g,
    /`\s*pass_mgr\s+get\s+(\S+)\s*`/g,
  ];

  for (const pattern of newPatterns) {
    let match;
    while ((match = pattern.exec(command)) !== null) {
      if (!seen.has(match[0])) {
        seen.add(match[0]);
        results.push({
          key: match[1],
          fullMatch: match[0],
          subcommand: 'get-secret',
        });
      }
    }
  }

  for (const pattern of legacyPatterns) {
    let match;
    while ((match = pattern.exec(command)) !== null) {
      if (!seen.has(match[0])) {
        seen.add(match[0]);
        results.push({
          key: match[1],
          fullMatch: match[0],
          subcommand: 'get',
        });
      }
    }
  }

  return results;
}

/**
 * Execute pass_mgr to retrieve a secret.
 * Uses the same env vars that the caller passes so pcguard checks pass.
 */
async function fetchPassword(
  subcommand: string,
  key: string,
  env: Record<string, string>,
): Promise<string> {
  return new Promise((resolve, reject) => {
    const passMgrPath = env.PASS_MGR_PATH || process.env.PASS_MGR_PATH || 'pass_mgr';
    const args =
      subcommand === 'get-secret'
        ? ['get-secret', '--key', key]
        : ['get', key];

    const child = spawn(passMgrPath, args, {
      stdio: ['ignore', 'pipe', 'pipe'],
      env: { ...process.env, ...env },
    });

    let stdout = '';
    let stderr = '';
    child.stdout.on('data', (d) => (stdout += d.toString()));
    child.stderr.on('data', (d) => (stderr += d.toString()));
    child.on('close', (code) => {
      if (code !== 0) {
        reject(new Error(`pass_mgr ${subcommand} failed: ${stderr || stdout}`));
      } else {
        resolve(stdout.trim());
      }
    });
    child.on('error', reject);
  });
}

/**
 * Sanitize output by replacing passwords with ######
 */
function sanitizeOutput(output: string, passwords: string[]): string {
  let sanitized = output;
  for (const password of passwords) {
    if (password) {
      const escaped = password.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
      sanitized = sanitized.replace(new RegExp(escaped, 'g'), '######');
    }
  }
  return sanitized;
}

/**
 * Pre-resolve pass_mgr invocations, replace them inline, and collect passwords.
 */
async function replacePassMgrGets(
  command: string,
  env: Record<string, string>,
): Promise<{ command: string; passwords: string[] }> {
  const matches = extractPassMgrGets(command);
  const passwords: string[] = [];
  let replaced = command;

  for (const { key, fullMatch, subcommand } of matches) {
    const pw = await fetchPassword(subcommand, key, env);
    passwords.push(pw);
    replaced = replaced.split(fullMatch).join(pw);
  }

  return { command: replaced, passwords };
}

/**
 * Safe exec wrapper that handles pass_mgr get commands and sanitizes output.
 */
export async function pcexec(
  command: string,
  options: PcExecOptions = {},
): Promise<PcExecResult> {
  // Build environment
  const env: Record<string, string> = {};

  for (const [k, v] of Object.entries(process.env)) {
    if (v !== undefined) env[k] = v;
  }
  if (options.env) Object.assign(env, options.env);

  // Pre-resolve passwords
  let finalCommand = command;
  let passwords: string[] = [];

  const resolved = await replacePassMgrGets(command, env);
  finalCommand = resolved.command;
  passwords = resolved.passwords;

  return new Promise((resolve, reject) => {
    const spawnOptions: SpawnOptions = {
      cwd: options.cwd,
      env,
      shell: options.shell,
      windowsHide: options.windowsHide,
      uid: options.uid,
      gid: options.gid,
    };

    const child = spawn('bash', ['-c', finalCommand], spawnOptions);

    let stdout = '';
    let stderr = '';
    let killed = false;
    let timeoutId: NodeJS.Timeout | null = null;

    if (options.timeout && options.timeout > 0) {
      timeoutId = setTimeout(() => {
        killed = true;
        child.kill(options.killSignal || 'SIGTERM');
      }, options.timeout);
    }

    child.stdout?.on('data', (data) => {
      stdout += data.toString();
      if (options.maxBuffer && stdout.length > options.maxBuffer) {
        child.kill(options.killSignal || 'SIGTERM');
      }
    });

    child.stderr?.on('data', (data) => {
      stderr += data.toString();
      if (options.maxBuffer && stderr.length > options.maxBuffer) {
        child.kill(options.killSignal || 'SIGTERM');
      }
    });

    child.on('close', (code, signal) => {
      if (timeoutId) clearTimeout(timeoutId);

      const sanitizedStdout = sanitizeOutput(stdout, passwords);
      const sanitizedStderr = sanitizeOutput(stderr, passwords);

      if (code === 0) {
        resolve({
          stdout: sanitizedStdout,
          stderr: sanitizedStderr,
          exitCode: 0,
          command: finalCommand,
        });
      } else {
        const error = new Error(`Command failed: ${command}`) as PcExecError;
        error.code = code ?? undefined;
        error.signal = signal ?? undefined;
        error.stdout = sanitizedStdout;
        error.stderr = sanitizedStderr;
        error.killed = killed;
        reject(error);
      }
    });

    child.on('error', (err) => {
      if (timeoutId) clearTimeout(timeoutId);
      const error = new Error(`Failed to execute command: ${err.message}`) as PcExecError;
      error.stdout = sanitizeOutput(stdout, passwords);
      error.stderr = sanitizeOutput(stderr, passwords);
      reject(error);
    });
  });
}

/**
 * Synchronous version — password substitution is NOT supported here
 * (use async pcexec for pass_mgr integration).
 */
export function pcexecSync(
  command: string,
  options: PcExecOptions = {},
): PcExecResult {
  const { execSync } = require('child_process');

  const env: Record<string, string> = {};
  for (const [k, v] of Object.entries(process.env)) {
    if (v !== undefined) env[k] = v;
  }
  if (options.env) Object.assign(env, options.env);

  try {
    const stdout = execSync(command, {
      cwd: options.cwd,
      env,
      shell: options.shell as any,
      encoding: 'utf8',
      windowsHide: options.windowsHide,
      uid: options.uid,
      gid: options.gid,
      maxBuffer: options.maxBuffer,
      timeout: options.timeout,
      killSignal: options.killSignal,
    });

    return { stdout: stdout.toString(), stderr: '', exitCode: 0, command };
  } catch (err: any) {
    const error = new Error(`Command failed: ${command}`) as PcExecError;
    error.code = err.status;
    error.signal = err.signal;
    error.stdout = err.stdout?.toString() || '';
    error.stderr = err.stderr?.toString() || '';
    throw error;
  }
}

export default pcexec;