From 59f8be3b9237efea6b4e51b18ae143f69ef50882 Mon Sep 17 00:00:00 2001
From: Eric Daspet <eric.daspet@survol.fr>
Date: Thu, 14 Feb 2013 15:53:40 +0100
Subject: [PATCH] Throw Exception on broken signature

This is related to issue #1562

With a fresh installation of Composer I had the following message:

> The contents of https://packagist.org/p/providers-latest.json do not
match its signature, this is most likely due to a temporary glitch but
could indicate a man-in-the-middle attack.
> Try running composer again and please report it if it still persists.

This was *probably* a temporary glitch, as the error did not appear
again, even after a full reinstallation of all packages.

*However* Composer had no way to differentiate a man-in-the-middle
attack and a temporary glitch. The installation / update did continue
despite the problem and files where installed / updates with no easy
rollback. These files may have been corrupted with malicious code and I
have no way to check they don't.

This is a *serious* security issue.

The code in [ComposerRepository line
434](https://github.com/composer/composer/blob/master/src/Composer/Repos
itory/ComposerRepository.php#L434) states

```php
// TODO throw SecurityException and abort once we are sure this can not
happen accidentally
````

Even if the broken signature may happen in accidentally in a standard
process, if it may be a security issue, we have to abort the procedure,
or at least ask for confirmation to the user. If it helps continuing
despite the temporary glitch, it may be possible to add a command line
switch like `--ignore-signature` to force the process to continue.

Proposed :
Send a RepositorySecurityException instead of the warning, even if this
may happen accidentally
---
 .../Repository/ComposerRepository.php         |  2 +-
 .../RepositorySecurityException.php           | 22 +++++++++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100644 src/Composer/Repository/RepositorySecurityException.php

diff --git a/src/Composer/Repository/ComposerRepository.php b/src/Composer/Repository/ComposerRepository.php
index fdb7fa5cb..72a392641 100644
--- a/src/Composer/Repository/ComposerRepository.php
+++ b/src/Composer/Repository/ComposerRepository.php
@@ -431,8 +431,8 @@ class ComposerRepository extends ArrayRepository implements StreamableRepository
                         continue;
                     }
 
-                    // TODO throw SecurityException and abort once we are sure this can not happen accidentally
                     $this->io->write('<warning>The contents of '.$filename.' do not match its signature, this is most likely due to a temporary glitch but could indicate a man-in-the-middle attack. Try running composer again and please report it if it still persists.</warning>');
+                    throw new RepositorySecurityException('The contents of '.$filename.' do not match its signature');
                 }
                 $this->cache->write($cacheKey, $encoded);
 
diff --git a/src/Composer/Repository/RepositorySecurityException.php b/src/Composer/Repository/RepositorySecurityException.php
new file mode 100644
index 000000000..fbb33fadc
--- /dev/null
+++ b/src/Composer/Repository/RepositorySecurityException.php
@@ -0,0 +1,22 @@
+<?php
+
+/*
+ * This file is part of Composer.
+ *
+ * (c) 
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Composer\Repository;
+
+/**
+ * Thrown when a security problem, like a broken or missing signature
+ *
+ * @author Eric Daspet <edaspet@survol.fr>
+ */
+class Repository\RepositorySecurityException extends \Exception
+{
+	// nothing more, standard Exception
+}
\ No newline at end of file