Disallow plugins by throwing an exception if non-interactive to avoid half-broken runtime states (#10920)

* Disallow plugins by throwing an exception if non-interactive to avoid half-broken runtime states, fixes #10912
* Also allow BC mode for lock files older than 2.2.0 to keep plugins working there
* Allow locker to be accessed by plugin manager at init time
* Update allow-plugins docs

Co-authored-by: Damien Tournoud <damien@platform.sh>
Co-authored-by: Jordi Boggiano <j.boggiano@seld.be>

doc/06-config.md

@@ -52,7 +52,15 @@ and **false** to disallow while suppressing further warnings and prompts.
 }
 ```
 
-You can also set the config option itself to `false` to disallow all plugins, or `true` to allow all plugins to run (NOT recommended).
+You can also set the config option itself to `false` to disallow all plugins, or `true` to allow all plugins to run (NOT recommended). For example:
+
+```json
+{
+    "config": {
+        "allow-plugins": false
+    }
+}
+```
 
 ## use-include-path
 

src/Composer/Factory.php

@@ -427,6 +427,17 @@ class Factory
         // add installers to the manager (must happen after download manager is created since they read it out of $composer)
         $this->createDefaultInstallers($im, $composer, $io, $process);
 
+        // init locker if possible
+        if ($fullLoad && isset($composerFile)) {
+            $lockFile = self::getLockFile($composerFile);
+            if (!$config->get('lock') && file_exists($lockFile)) {
+                $io->writeError('<warning>'.$lockFile.' is present but ignored as the "lock" config option is disabled.</warning>');
+            }
+
+            $locker = new Package\Locker($io, new JsonFile($config->get('lock') ? $lockFile : Platform::getDevNull(), null, $io), $im, file_get_contents($composerFile), $process);
+            $composer->setLocker($locker);
+        }
+
         if ($fullLoad) {
             $globalComposer = null;
             if (realpath($config->get('home')) !== $cwd) {
@@ -439,17 +450,6 @@ class Factory
             $pm->loadInstalledPlugins();
         }
 
-        // init locker if possible
-        if ($fullLoad && isset($composerFile)) {
-            $lockFile = self::getLockFile($composerFile);
-            if (!$config->get('lock') && file_exists($lockFile)) {
-                $io->writeError('<warning>'.$lockFile.' is present but ignored as the "lock" config option is disabled.</warning>');
-            }
-
-            $locker = new Package\Locker($io, new JsonFile($config->get('lock') ? $lockFile : Platform::getDevNull(), null, $io), $im, file_get_contents($composerFile), $process);
-            $composer->setLocker($locker);
-        }
-
         if ($fullLoad) {
             $initEvent = new Event(PluginEvents::INIT);
             $composer->getEventDispatcher()->dispatch($initEvent->getName(), $initEvent);

src/Composer/Installer/PluginInstaller.php

@@ -47,6 +47,19 @@ class PluginInstaller extends LibraryInstaller
         return $packageType === 'composer-plugin' || $packageType === 'composer-installer';
     }
 
+    /**
+     * @inheritDoc
+     */
+    public function prepare($type, PackageInterface $package, PackageInterface $prevPackage = null)
+    {
+        // fail install process early if it going to fail due to a plugin not being allowed
+        if ($type === 'install' || $type === 'update') {
+            $this->composer->getPluginManager()->isPluginAllowed($package->getName(), false);
+        }
+
+        return parent::prepare($type, $package, $prevPackage);
+    }
+
     /**
      * @inheritDoc
      */

src/Composer/Package/Locker.php

@@ -318,6 +318,16 @@ class Locker
         return isset($lockData['aliases']) ? $lockData['aliases'] : array();
     }
 
+    /**
+     * @return string
+     */
+    public function getPluginApi()
+    {
+        $lockData = $this->getLockData();
+
+        return isset($lockData['plugin-api-version']) ? $lockData['plugin-api-version'] : '1.1.0';
+    }
+
     /**
      * @return array<string, mixed>
      */

src/Composer/Plugin/PluginManager.php

@@ -18,6 +18,7 @@ use Composer\Installer\InstallerInterface;
 use Composer\IO\IOInterface;
 use Composer\Package\BasePackage;
 use Composer\Package\CompletePackage;
+use Composer\Package\Locker;
 use Composer\Package\Package;
 use Composer\Package\Version\VersionParser;
 use Composer\Pcre\Preg;
@@ -82,9 +83,8 @@ class PluginManager
         $this->globalComposer = $globalComposer;
         $this->versionParser = new VersionParser();
         $this->disablePlugins = $disablePlugins;
-
+        $this->allowPluginRules = $this->parseAllowedPlugins($composer->getConfig()->get('allow-plugins'), $composer->getLocker());
-        $this->allowPluginRules = $this->parseAllowedPlugins($composer->getConfig()->get('allow-plugins'));
+        $this->allowGlobalPluginRules = $this->parseAllowedPlugins($globalComposer !== null ? $globalComposer->getConfig()->get('allow-plugins') : false, $globalComposer !== null ? $globalComposer->getLocker() : null);
-        $this->allowGlobalPluginRules = $this->parseAllowedPlugins($globalComposer !== null ? $globalComposer->getConfig()->get('allow-plugins') : false);
     }
 
     /**
@@ -653,12 +653,12 @@ class PluginManager
     }
 
     /**
-     * @param  array<string, bool>|bool|null $allowPluginsConfig
+     * @param  array<string, bool>|bool $allowPluginsConfig
      * @return array<non-empty-string, bool>|null
      */
-    private function parseAllowedPlugins($allowPluginsConfig)
+    private function parseAllowedPlugins($allowPluginsConfig, Locker $locker = null)
     {
-        if (null === $allowPluginsConfig) {
+        if (array() === $allowPluginsConfig && $locker !== null && $locker->isLocked() && version_compare($locker->getPluginApi(), '2.2.0', '<')) {
             return null;
         }
 
@@ -679,22 +679,28 @@ class PluginManager
     }
 
     /**
+     * @internal
+     *
      * @param string $package
      * @param bool $isGlobalPlugin
      * @return bool
      */
-    private function isPluginAllowed($package, $isGlobalPlugin)
+    public function isPluginAllowed($package, $isGlobalPlugin)
     {
-        static $warned = array();
+        if ($isGlobalPlugin) {
-        $rules = $isGlobalPlugin ? $this->allowGlobalPluginRules : $this->allowPluginRules;
+            $rules = &$this->allowGlobalPluginRules;
+        } else {
+            $rules = &$this->allowPluginRules;
+        }
 
+        // This is a BC mode for lock files created pre-Composer-2.2 where the expectation of
+        // an allow-plugins config being present cannot be made.
         if ($rules === null) {
             if (!$this->io->isInteractive()) {
-                if (!isset($warned['all'])) {
                 $this->io->writeError('<warning>For additional security you should declare the allow-plugins config with a list of packages names that are allowed to run code. See https://getcomposer.org/allow-plugins</warning>');
-                    $this->io->writeError('<warning>You have until July 2022 to add the setting. Composer will then switch the default behavior to disallow all plugins.</warning>');
+                $this->io->writeError('<warning>This warning will become an exception once you run composer update!</warning>');
-                    $warned['all'] = true;
+
-                }
+                $rules = array('{}' => true);
 
                 // if no config is defined we allow all plugins for BC
                 return true;
@@ -714,24 +720,20 @@ class PluginManager
             return false;
         }
 
-        if (!isset($warned[$package])) {
         if ($this->io->isInteractive()) {
             $composer = $isGlobalPlugin && $this->globalComposer !== null ? $this->globalComposer : $this->composer;
 
             $this->io->writeError('<warning>'.$package.($isGlobalPlugin ? ' (installed globally)' : '').' contains a Composer plugin which is currently not in your allow-plugins config. See https://getcomposer.org/allow-plugins</warning>');
             while (true) {
-                    switch ($answer = $this->io->ask('Do you trust "<info>'.$package.'</info>" to execute code and wish to enable it now? (writes "allow-plugins" to composer.json) [<comment>y,n,d,?</comment>] ', '?')) {
+                switch ($answer = $this->io->ask('Do you trust "<info>'.$package.'</info>" to execute code and wish to enable it now? (writes "allow-plugins" to composer.json) [<comment>y,n,d,?</comment>] ',
+                    '?')) {
                     case 'y':
                     case 'n':
                     case 'd':
                         $allow = $answer === 'y';
 
                         // persist answer in current rules to avoid prompting again if the package gets reloaded
-                            if ($isGlobalPlugin) {
+                        $rules[BasePackage::packageNameToRegexp($package)] = $allow;
-                                $this->allowGlobalPluginRules[BasePackage::packageNameToRegexp($package)] = $allow;
-                            } else {
-                                $this->allowPluginRules[BasePackage::packageNameToRegexp($package)] = $allow;
-                            }
 
                         // persist answer in composer.json if it wasn't simply discarded
                         if ($answer === 'y' || $answer === 'n') {
@@ -751,13 +753,12 @@ class PluginManager
                         break;
                 }
             }
-            } else {
-                $this->io->writeError('<warning>'.$package.($isGlobalPlugin ? ' (installed globally)' : '').' contains a Composer plugin which is blocked by your allow-plugins config. You may add it to the list if you consider it safe. See https://getcomposer.org/allow-plugins</warning>');
-                $this->io->writeError('<warning>You can run "composer '.($isGlobalPlugin ? 'global ' : '').'config --no-plugins allow-plugins.'.$package.' [true|false]" to enable it (true) or keep it disabled and suppress this warning (false)</warning>');
-            }
-            $warned[$package] = true;
         }
 
-        return false;
+        throw new \UnexpectedValueException(
+            $package.($isGlobalPlugin ? ' (installed globally)' : '').' contains a Composer plugin which is blocked by your allow-plugins config. You may add it to the list if you consider it safe.'.PHP_EOL.
+            'You can run "composer '.($isGlobalPlugin ? 'global ' : '').'config --no-plugins allow-plugins.'.$package.' [true|false]" to enable it (true) or disable it explicitly and suppress this exception (false)'.PHP_EOL.
+            'See https://getcomposer.org/allow-plugins'
+        );
     }
 }