Further clean up code, implement signature checking

php/composer.json

@@ -7,8 +7,5 @@
     "minimum-stability": "dev",
     "autoload": {
         "psr-4": {"GHE\\": "src/"}
-    },
-    "require-dev": {
-        "phpunit/phpunit": "^6.4"
     }
 }

php/mass-rebuild-filter.php

@@ -31,21 +31,6 @@ function runner($msg) {
     echo "Msg Sha: " . md5($msg->body) . "\n";
     $in = json_decode($msg->body);
 
-    try {
-        $etype = \GHE\EventClassifier::classifyEvent($in);
-
-        if ($etype != "pull_request") {
-            echo "Skipping event type: $etype\n";
-            $msg->delivery_info['channel']->basic_ack($msg->delivery_info['delivery_tag']);
-            return true;
-        }
-    } catch (\GHE\EventClassifierUnknownException $e) {
-        echo "Skipping unknown event type\n";
-        print_r($in);
-        $msg->delivery_info['channel']->basic_ack($msg->delivery_info['delivery_tag']);
-        return true;
-    }
-
     if (!\GHE\ACL::isRepoEligible($in->repository->full_name)) {
         echo "Repo not authorized (" . $in->repository->full_name . ")\n";
         $msg->delivery_info['channel']->basic_ack($msg->delivery_info['delivery_tag']);

php/src/EventClassifier.php

@@ -1,185 +0,0 @@
-<?php
-
-namespace GHE;
-
-class EventClassifier {
-    public static function classifyEvent($payload) {
-        if (self::isIssuesEvent($payload)) {
-            return "issues";
-        }
-
-        if (self::isIssueComment($payload)) {
-            return "issue_comment";
-        }
-
-        if (self::isCommitComment($payload)) {
-            return "commit_comment";
-        }
-
-        if (self::isPullRequestReviewComment($payload)) {
-            return "pull_request_review_comment";
-        }
-
-        if (self::isPullRequestReviewEvent($payload)) {
-            return "pull_request_review";
-        }
-
-        if (self::isPullRequestEvent($payload)) {
-            return "pull_request";
-        }
-
-        if (self::isStatusEvent($payload)) {
-            return "status";
-        }
-
-        if (self::isPushEvent($payload)) {
-            return "push";
-        }
-
-        if (self::isWatchEvent($payload)) {
-            return "watch";
-        }
-
-        if (self::isForkEvent($payload)) {
-            return "fork";
-        }
-
-        if (self::isCreateEvent($payload)) {
-            return "create";
-        }
-
-        if (self::isDeleteEvent($payload)) {
-            return "delete";
-        }
-
-        if (self::isProjectEvent($payload)) {
-            return "project";
-        }
-
-        if (self::isProjectCardEvent($payload)) {
-            return "project_card";
-        }
-
-        if (self::isProjectColumnEvent($payload)) {
-            return "project_column";
-        }
-
-        if (self::isLabelEvent($payload)) {
-            return "label";
-        }
-
-        throw new EventClassifierUnknownException();
-    }
-
-    public static function isIssuesEvent($payload) {
-        return isset($payload->issue)
-            && !isset($payload->comment)
-            && isset($payload->action)
-            && in_array($payload->action,
-                        [ "assigned", "unassigned", "labeled",
-                          "unlabeled", "opened", "edited",
-                          "milestoned", "demilestoned", "closed",
-                          "reopened" ]);
-    }
-
-    public static function isIssueComment($payload) {
-        return isset($payload->issue)
-            && isset($payload->comment)
-            && isset($payload->action)
-            && in_array($payload->action,
-                        ['created', 'edited', 'deleted']);
-    }
-
-    public static function isCommitComment($payload) {
-        return !isset($payload->issue)
-            && !isset($payload->pull_request)
-            && isset($payload->comment)
-            && isset($payload->action);
-    }
-
-    public static function isPullRequestReviewComment($payload) {
-        return !isset($payload->issue)
-            && isset($payload->pull_request)
-            && isset($payload->comment)
-            && isset($payload->action)
-            && in_array($payload->action,
-                        ['created', 'edited', 'deleted']);
-    }
-
-    public static function isPullRequestReviewEvent($payload) {
-        return isset($payload->review)
-            && isset($payload->pull_request)
-            && isset($payload->action)
-            && in_array($payload->action,
-                        ['submitted', 'edited', 'dismissed']);
-    }
-
-    public static function isPullRequestEvent($payload) {
-        return isset($payload->number)
-            && isset($payload->pull_request)
-            && isset($payload->action)
-            && in_array($payload->action,
-                        [ "assigned", "unassigned",
-                          "review_requested",
-                          "review_request_removed", "labeled",
-                          "unlabeled", "opened", "edited", "closed",
-                          "reopened", "synchronize" ]);
-    }
-
-    public static function isStatusEvent($payload) {
-        return isset($payload->sha)
-            && isset($payload->commit)
-            && isset($payload->state)
-            && in_array($payload->state,
-                        ['pending', 'success', 'failure', 'error']);
-
-    }
-
-    public static function isPushEvent($payload) {
-        return isset($payload->before)
-            && isset($payload->after);
-    }
-
-    public static function isWatchEvent($payload) {
-        return isset($payload->action)
-            && $payload->action == "started";
-    }
-
-    public static function isForkEvent($payload) {
-        return isset($payload->forkee);
-    }
-
-    public static function isCreateEvent($payload) {
-        return isset($payload->ref_type)
-            && isset($payload->ref)
-            && isset($payload->master_branch);
-    }
-
-    public static function isDeleteEvent($payload) {
-        return isset($payload->ref_type)
-            && isset($payload->ref)
-            && !isset($payload->master_branch);
-    }
-
-    public static function isProjectEvent($payload) {
-        return isset($payload->project);
-    }
-
-    public static function isProjectCardEvent($payload) {
-        return isset($payload->project_card);
-    }
-
-    public static function isProjectColumnEvent($payload) {
-        return isset($payload->project_column);
-    }
-
-    public static function isLabelEvent($payload) {
-        return isset($payload->label)
-            && isset($payload->action)
-            && in_array($payload->action,
-                        ['created', 'edited', 'deleted']);
-    }
-
-}
-
-class EventClassifierUnknownException extends \Exception{};

php/web/index.php

@@ -1,44 +1,153 @@
 <?php
 
+ob_start();
+
 require_once __DIR__ . '/../config.php';
 use PhpAmqpLib\Message\AMQPMessage;
 
-$connection = rabbitmq_conn();
+class DumpableException extends \Exception{}
-$channel = $connection->channel();
+class InvalidPayloadException extends DumpableException {}
+class InvalidSignatureException extends DumpableException {}
+class InvalidEventTypeException extends DumpableException {}
+class ValidationFailureException extends DumpableException {}
+class ExecutionFailureException extends DumpableException {}
 
-$raw = file_get_contents('php://input');
+function payload() {
-$input = json_decode($raw);
+    if (!isset($_SERVER)) {
-if (!isset($input->repository->full_name)) {
+        throw new InvalidPayloadException('_SERVER undefined');
-   echo "no full_name set?";
+    }
-   exit();
+
-} else {
+    if (!isset($_SERVER['CONTENT_TYPE'])) {
-    echo "full_name present\n";
+        throw new InvalidPayloadException('CONTENT_TYPE not set in _SERVER');
+    }
+
+    switch ($_SERVER['CONTENT_TYPE']) {
+    case 'application/json':
+        $input = file_get_contents('php://input');
+        if ($input === false) {
+            throw new InvalidPayloadException('Failed to read php://input for application/json');
+        } else {
+            return $input;
+        }
+    case 'application/x-www-form-urlencoded':
+        if (!isset($_POST)) {
+            throw new InvalidPayloadException('_POST undefined');
+        }
+
+        if (!isset($_POST['payload'])) {
+            throw new InvalidPayloadException('payload not set in _POST');
+        }
+
+        return $_POST['payload'];
+    default:
+        throw new InvalidPayloadException('Unsupported content type: ' . $_SERVER['HTTP_CONTENT_TYPE']);
+    }
 }
 
-$name = strtolower($input->repository->full_name);
+function signature() {
-if (!GHE\ACL::isRepoEligible($name)) {
+    if (!isset($_SERVER)) {
-    echo "repo not in ok name list";
+        throw new InvalidSignatureException('_SERVER undefined');
-    exit(1);
+    }
-} else {
+
-    echo "full_name ok\n";
+    if (!isset($_SERVER['HTTP_X_HUB_SIGNATURE'])) {
+        throw new InvalidSignatureException('HTTP_X_HUB_SIGNATURE absent from _SERVER');
+    }
+
+    return $_SERVER['HTTP_X_HUB_SIGNATURE'];
 }
 
-$dec = $channel->exchange_declare('github-events', 'topic', false, true, false);
+function event_type() {
+    if (!isset($_SERVER)) {
+        throw new InvalidEventTypeException('_SERVER undefined');
+    }
 
-$message = new AMQPMessage(json_encode($input),
+    if (!isset($_SERVER['HTTP_X_GITHUB_EVENT'])) {
-                           array(
+        throw new InvalidEventTypeException('HTTP_X_GITHUB_EVENT absent from _SERVER');
-                               'content_type' => 'application/json',
+    }
-                               'delivery_mode' => AMQPMessage::DELIVERY_MODE_PERSISTENT,
+
-                           ));
+    $type = trim($_SERVER['HTTP_X_GITHUB_EVENT']);
+
+    if (strlen($type) === 0) {
+        throw new InvalidEventTypeException('After trimming, event type is zero-length');
+    }
+
+    return $type;
+}
+
+function validate_payload_signature($secret, $payload, $signature) {
+    if (!extension_loaded('hash')) {
+        throw new ValidationFailureException('Missing hash extension');
+    }
+
+    $components = explode('=', $signature, 2);
+    if (count($components) != 2) {
+        throw new ValidationFailureException('Provided signature seems invalid after splitting on =');
+    }
+
+    $algo = $components[0];
+    $provided_hash = $components[1];
+
+    if (!in_array($algo, hash_algos(), true)) {
+        throw new ValidationFailureException("Hash algorithm '$algo' is not supported by the extension.");
+    }
+
+    $ok_algos = [
+        'sha1',
+        'sha256',
+        'sha512',
+    ];
+    if (!in_array($algo, $ok_algos, true)) {
+        throw new ValidationFailureException("Hash algorithm '$algo' is not considered okay");
+    }
+
+    $calculated_hash = hash_hmac($algo, $payload, $secret);
+
+    return hash_equals($provided_hash, $calculated_hash);
+}
 
 try {
-    $etype = \GHE\EventClassifier::classifyEvent($input);
+    $raw = payload();
-} catch (\GHE\EventClassifierUnknownException $e) {
+    if (!validate_payload_signature(gh_secret(), $raw, signature())) {
-    $etype = "unknown";
+        throw new ExecutionFailureException('Failed to validate signature');
+    }
+
+    $input = json_decode($raw);
+    if ($input === null) {
+        throw new ExecutionFailureException('Failed to decode the JSON');
+    }
+
+    if (!isset($input->repository)) {
+        throw new\ExecutionFailureException('Dataset does not have a repository');
+    }
+
+    if (!isset($input->repository->full_name)) {
+        throw new ExecutionFailureException('Dataset repository does not have a name');
+    }
+
+    $name = strtolower($input->repository->full_name);
+    $eventtype = event_type();
+
+    $connection = rabbitmq_conn();
+    $channel = $connection->channel();
+
+    $dec = $channel->exchange_declare('github-events', 'topic', false, true, false);
+
+    $message = new AMQPMessage(json_encode($input),
+                               array(
+                                   'content_type' => 'application/json',
+                                   'delivery_mode' => AMQPMessage::DELIVERY_MODE_PERSISTENT,
+                               ));
+
+    $routing_key = "$eventtype.$name";
+    $rec = $channel->basic_publish($message, 'github-events', $routing_key);
+
+    echo "ok";
+} catch (DumpableException $e) {
+    header($_SERVER["SERVER_PROTOCOL"]." 400 Eh", true, 400);
+    var_dump($e);
+    echo ob_get_clean();
+} catch (\Exception $e) {
+    header($_SERVER["SERVER_PROTOCOL"]." 400 Meh", true, 400);
+    var_dump(get_class($e));
+    echo ob_get_clean();
 }
-
-$routing_key = "$etype.$name";
-var_dump($routing_key);
-$rec = $channel->basic_publish($message, 'github-events', $routing_key);
-
-echo "ok";