fix: Remove protection on CA file after upgrade (#48)

* fix: Remove protection on CA file after upgrade

* revamped uninstall process

* chore: win32 delete warning

src/certificate-authority.ts

@@ -1,21 +1,20 @@
-import path from 'path';
 import {
   unlinkSync as rm,
   readFileSync as readFile,
-  writeFileSync as writeFile,
-  existsSync as exists
+  writeFileSync as writeFile
 } from 'fs';
-import { sync as rimraf } from 'rimraf';
 import createDebug from 'debug';
 
 import {
+  domainsDir,
+  rootCADir,
+  ensureConfigDirs,
+  getLegacyConfigDir,
   rootCAKeyPath,
   rootCACertPath,
   caSelfSignConfig,
   opensslSerialFilePath,
   opensslDatabaseFilePath,
-  isWindows,
-  isLinux,
   caVersionFile
 } from './constants';
 import currentPlatform from './platforms';
@@ -30,10 +29,11 @@ const debug = createDebug('devcert:certificate-authority');
  * per-app certs.
  */
 export default async function installCertificateAuthority(options: Options = {}): Promise<void> {
-  debug(`Checking if older devcert install is present`);
-  scrubOldInsecureVersions();
+  debug(`Uninstalling existing certificates, which will be void once any existing CA is gone`);
+  uninstall();
+  ensureConfigDirs();
 
-  debug(`Generating a root certificate authority`);
+  debug(`Making a temp working directory for files to copied in`);
   let rootKeyPath = mktmp();
 
   debug(`Generating the OpenSSL configuration needed to setup the certificate authority`);
@@ -52,39 +52,6 @@ export default async function installCertificateAuthority(options: Options = {})
   await currentPlatform.addToTrustStores(rootCACertPath, options);
 }
 
-/**
- * Older versions of devcert left the root certificate keys unguarded and
- * accessible by userland processes. Here, we check for evidence of this older
- * version, and if found, we delete the root certificate keys to remove the
- * attack vector.
- */
-function scrubOldInsecureVersions() {
-  // Use the old verion's logic for determining config directory
-  let configDir: string;
-  if (isWindows && process.env.LOCALAPPDATA) {
-    configDir = path.join(process.env.LOCALAPPDATA, 'devcert', 'config');
-  } else {
-    let uid = process.getuid && process.getuid();
-    let userHome = (isLinux && uid === 0) ? path.resolve('/usr/local/share') : require('os').homedir();
-    configDir = path.join(userHome, '.config', 'devcert');
-  }
-
-  // Delete the root certificate keys, as well as the generated app certificates
-  debug(`Checking ${ configDir } for legacy files ...`);
-  [
-    path.join(configDir, 'openssl.conf'),
-    path.join(configDir, 'devcert-ca-root.key'),
-    path.join(configDir, 'devcert-ca-root.crt'),
-    path.join(configDir, 'devcert-ca-version'),
-    path.join(configDir, 'certs')
-  ].forEach((filepath) => {
-    if (exists(filepath)) {
-      debug(`Removing legacy file: ${ filepath }`)
-      rimraf(filepath);
-    }
-  });
-}
-
 /**
  * Initializes the files OpenSSL needs to sign certificates as a certificate
  * authority, as well as our CA setup version
@@ -111,3 +78,67 @@ async function saveCertificateAuthorityCredentials(keypath: string) {
   let key = readFile(keypath, 'utf-8');
   await currentPlatform.writeProtectedFile(rootCAKeyPath, key);
 }
+
+
+function certErrors(): string {
+  try {
+    openssl(`x509 -in "${ rootCACertPath }" -noout`);
+    return '';
+  } catch (e) {
+    return e.toString();
+  }
+}
+
+// This function helps to migrate from v1.0.x to >= v1.1.0.
+/**
+ * Smoothly migrate the certificate storage from v1.0.x to >= v1.1.0.
+ * In v1.1.0 there are new options for retrieving the CA cert directly,
+ * to help third-party Node apps trust the root CA.
+ * 
+ * If a v1.0.x cert already exists, then devcert has written it with
+ * platform.writeProtectedFile(), so an unprivileged readFile cannot access it.
+ * Pre-detect and remedy this; it should only happen once per installation.
+ */
+export async function ensureCACertReadable(options: Options = {}): Promise<void> {
+  if (!certErrors()) {
+    return;
+  }
+  /**
+   * on windows, writeProtectedFile left the cert encrypted on *nix, the cert
+   * has no read permissions either way, openssl will fail and that means we
+   * have to fix it
+   */
+  try {
+    const caFileContents = await currentPlatform.readProtectedFile(rootCACertPath);
+    currentPlatform.deleteProtectedFiles(rootCACertPath);
+    writeFile(rootCACertPath, caFileContents);
+  } catch (e) {
+    return installCertificateAuthority(options);
+  }
+
+  // double check that we have a live one
+  const remainingErrors = certErrors();
+  if (remainingErrors) {
+    return installCertificateAuthority(options);
+  }
+}
+
+/**
+ * Remove as much of the devcert files and state as we can. This is necessary
+ * when generating a new root certificate, and should be available to API
+ * consumers as well.
+ * 
+ * Not all of it will be removable. If certutil is not installed, we'll leave
+ * Firefox alone. We try to remove files with maximum permissions, and if that
+ * fails, we'll silently fail.
+ * 
+ * It's also possible that the command to untrust will not work, and we'll
+ * silently fail that as well; with no existing certificates anymore, the
+ * security exposure there is minimal.
+ */
+export function uninstall(): void {
+  currentPlatform.removeFromTrustStores(rootCACertPath);
+  currentPlatform.deleteProtectedFiles(domainsDir);
+  currentPlatform.deleteProtectedFiles(rootCADir);
+  currentPlatform.deleteProtectedFiles(getLegacyConfigDir());
+}

src/constants.ts

@@ -56,6 +56,23 @@ export const rootCADir = configPath('certificate-authority');
 export const rootCAKeyPath = configPath('certificate-authority', 'private-key.key');
 export const rootCACertPath = configPath('certificate-authority', 'certificate.cert');
 
-mkdirp(configDir);
-mkdirp(domainsDir);
-mkdirp(rootCADir);
+
+
+// Exposed for uninstallation purposes.
+export function getLegacyConfigDir(): string {
+  if (isWindows && process.env.LOCALAPPDATA) {
+    return path.join(process.env.LOCALAPPDATA, 'devcert', 'config');
+  } else {
+    let uid = process.getuid && process.getuid();
+    let userHome = (isLinux && uid === 0) ? path.resolve('/usr/local/share') : require('os').homedir();
+    return path.join(userHome, '.config', 'devcert');
+  }
+}
+
+export function ensureConfigDirs() {
+  mkdirp(configDir);
+  mkdirp(domainsDir);
+  mkdirp(rootCADir);
+}
+
+ensureConfigDirs();

src/index.ts

@@ -12,9 +12,10 @@ import {
   rootCACertPath
 } from './constants';
 import currentPlatform from './platforms';
-import installCertificateAuthority from './certificate-authority';
+import installCertificateAuthority, { ensureCACertReadable, uninstall } from './certificate-authority';
 import generateDomainCertificate from './certificates';
 import UI, { UserInterface } from './user-interface';
+export { uninstall };
 
 const debug = createDebug('devcert');
 
@@ -84,6 +85,9 @@ export async function certificateFor<O extends Options>(domain: string, options:
   if (!exists(rootCAKeyPath)) {
     debug('Root CA is not installed yet, so it must be our first run. Installing root CA ...');
     await installCertificateAuthority(options);
+  } else if (options.getCaBuffer || options.getCaPath) {
+    debug('Root CA is not readable, but it probably is because an earlier version of devcert locked it. Trying to fix...');
+    await ensureCACertReadable(options);
   }
 
   if (!exists(pathForDomain(domain, `certificate.crt`))) {

src/platforms/darwin.ts

@@ -4,11 +4,12 @@ import createDebug from 'debug';
 import { sync as commandExists } from 'command-exists';
 import { run } from '../utils';
 import { Options } from '../index';
-import { addCertificateToNSSCertDB, openCertificateInFirefox, closeFirefox } from './shared';
+import { addCertificateToNSSCertDB, assertNotTouchingFiles, openCertificateInFirefox, closeFirefox, removeCertificateFromNSSCertDB } from './shared';
 import { Platform } from '.';
 
 const debug = createDebug('devcert:platforms:macos');
 
+const getCertUtilPath = () => path.join(run('brew --prefix nss').toString().trim(), 'bin', 'certutil');
 
 export default class MacOSPlatform implements Platform {
 
@@ -48,26 +49,45 @@ export default class MacOSPlatform implements Platform {
           return await openCertificateInFirefox(this.FIREFOX_BIN_PATH, certificatePath);
         }
       }
-      let certutilPath = path.join(run('brew --prefix nss').toString().trim(), 'bin', 'certutil');
       await closeFirefox();
-      await addCertificateToNSSCertDB(this.FIREFOX_NSS_DIR, certificatePath, certutilPath);
+      await addCertificateToNSSCertDB(this.FIREFOX_NSS_DIR, certificatePath, getCertUtilPath());
     } else {
       debug('Firefox does not appear to be installed, skipping Firefox-specific steps...');
     }
   }
+
+  removeFromTrustStores(certificatePath: string) {
+    debug('Removing devcert root CA from macOS system keychain');
+    try {
+      run(`sudo security remove-trusted-cert -d "${ certificatePath }"`);
+    } catch(e) {
+      debug(`failed to remove ${ certificatePath } from macOS cert store, continuing. ${ e.toString() }`);
+    }
+    if (this.isFirefoxInstalled() && this.isNSSInstalled()) {
+      debug('Firefox install and certutil install detected. Trying to remove root CA from Firefox NSS databases');
+      removeCertificateFromNSSCertDB(this.FIREFOX_NSS_DIR, certificatePath, getCertUtilPath());
+    }
+  }
 
   async addDomainToHostFileIfMissing(domain: string) {
     let hostsFileContents = read(this.HOST_FILE_PATH, 'utf8');
     if (!hostsFileContents.includes(domain)) {
       run(`echo '\n127.0.0.1 ${ domain }' | sudo tee -a "${ this.HOST_FILE_PATH }" > /dev/null`);
     }
   }
+
+  deleteProtectedFiles(filepath: string) {
+    assertNotTouchingFiles(filepath, 'delete');
+    run(`sudo rm -rf "${filepath}"`);
+  }
 
   async readProtectedFile(filepath: string) {
+    assertNotTouchingFiles(filepath, 'read');
     return (await run(`sudo cat "${filepath}"`)).toString().trim();
   }
 
   async writeProtectedFile(filepath: string, contents: string) {
+    assertNotTouchingFiles(filepath, 'write');
     if (exists(filepath)) {
       await run(`sudo rm "${filepath}"`);
     }

src/platforms/index.ts

@@ -3,7 +3,9 @@ import { Options } from '../index';
 
 export interface Platform {
    addToTrustStores(certificatePath: string, options?: Options): Promise<void>;
+   removeFromTrustStores(certificatePath: string): void;
    addDomainToHostFileIfMissing(domain: string): Promise<void>;
+   deleteProtectedFiles(filepath: string): void;
    readProtectedFile(filepath: string): Promise<string>;
    writeProtectedFile(filepath: string, contents: string): Promise<void>;
 }

src/platforms/linux.ts

@@ -2,7 +2,7 @@ import path from 'path';
 import { existsSync as exists, readFileSync as read, writeFileSync as writeFile } from 'fs';
 import createDebug from 'debug';
 import { sync as commandExists } from 'command-exists';
-import { addCertificateToNSSCertDB, openCertificateInFirefox, closeFirefox } from './shared';
+import { addCertificateToNSSCertDB, assertNotTouchingFiles, openCertificateInFirefox, closeFirefox, removeCertificateFromNSSCertDB } from './shared';
 import { run } from '../utils';
 import { Options } from '../index';
 import UI from '../user-interface';
@@ -67,6 +67,23 @@ export default class LinuxPlatform implements Platform {
       debug('Chrome does not appear to be installed, skipping Chrome-specific steps...');
     }
   }
+
+  removeFromTrustStores(certificatePath: string) {
+    try {
+      run(`sudo rm /usr/local/share/ca-certificates/devcert.crt`);
+      run(`sudo update-ca-certificates`); 
+    } catch (e) {
+      debug(`failed to remove ${ certificatePath } from /usr/local/share/ca-certificates, continuing. ${ e.toString() }`);
+    }
+    if (commandExists('certutil')) {
+      if (this.isFirefoxInstalled()) {
+        removeCertificateFromNSSCertDB(this.FIREFOX_NSS_DIR, certificatePath, 'certutil');
+      }
+      if (this.isChromeInstalled()) {
+        removeCertificateFromNSSCertDB(this.CHROME_NSS_DIR, certificatePath, 'certutil');
+      }
+    }
+  }
 
   async addDomainToHostFileIfMissing(domain: string) {
     let hostsFileContents = read(this.HOST_FILE_PATH, 'utf8');
@@ -75,11 +92,18 @@ export default class LinuxPlatform implements Platform {
     }
   }
 
+  deleteProtectedFiles(filepath: string) {
+    assertNotTouchingFiles(filepath, 'delete');
+    run(`sudo rm -rf "${filepath}"`);
+  }
+
   async readProtectedFile(filepath: string) {
+    assertNotTouchingFiles(filepath, 'read');
     return (await run(`sudo cat "${filepath}"`)).toString().trim();
   }
 
   async writeProtectedFile(filepath: string, contents: string) {
+    assertNotTouchingFiles(filepath, 'write');
     if (exists(filepath)) {
       await run(`sudo rm "${filepath}"`);
     }
@@ -88,7 +112,6 @@ export default class LinuxPlatform implements Platform {
     await run(`sudo chmod 600 "${filepath}"`);
   }
 
-
   private isFirefoxInstalled() {
     return exists(this.FIREFOX_BIN_PATH);
   }