From a698e91dd304e43ce70923e17dd5c0b5622b8200 Mon Sep 17 00:00:00 2001
From: Daniil Gentili <daniil.gentili.dg@gmail.com>
Date: Fri, 9 Jun 2017 20:56:13 +0100
Subject: [PATCH] Fixed CTR encryption and downloading of CDN files

---
 bot.php                                       |  3 +-
 src/danog/MadelineProto/MTProto.php           | 28 +++++++++++---
 .../MTProtoTools/AuthKeyHandler.php           | 11 ------
 .../MadelineProto/MTProtoTools/Crypt.php      |  3 +-
 .../MadelineProto/MTProtoTools/Files.php      | 37 ++++++++++---------
 .../MTProtoTools/MsgIdHandler.php             |  6 +--
 tests/testing.php                             |  2 +-
 7 files changed, 49 insertions(+), 41 deletions(-)

diff --git a/bot.php b/bot.php
index 8f15386a..46d0320e 100755
--- a/bot.php
+++ b/bot.php
@@ -27,7 +27,8 @@ try {
         die;
     }
 }
-var_dump($MadelineProto->rle_decode($MadelineProto->base64url_decode('gRuWfE2EXVJtaecDLpxYs39tElkZtzLo2mwsdmkuRbZQLO6ofKSoTHedbY1N9lAeUfvgE8wqHIF1VJ95YIyCCLswdZlmf-RWdph_C8wcUeSxtNCTE1gdbmiZp77uIT77bDbUHHbNyfgsKwY30aZS91snXwIrOulsGGA_j7VQ0k9TzGO9AczSj0LZt6kVpPpXKqSraHopH59Tpv4UCX3qXPa5XbcyodpOIL_VN5TtpfEUxoF5asavCOgNj6V4KInLDjkpLr-8dgViLUGRZagxr0EFHUs7DT9dW66_A4_qnszPlIw6GHOIlhLxV8emke0JV_hvATN11uT_RlnHNY83vQ')));
+//var_dump($MadelineProto->API->get_config([], ['datacenter' => $MadelineProto->API->datacenter->curdc]));
+//var_dump($MadelineProto->API->settings['connection']);
 
 $offset = 0;
 while (true) {
diff --git a/src/danog/MadelineProto/MTProto.php b/src/danog/MadelineProto/MTProto.php
index 4f2d974c..0424b322 100644
--- a/src/danog/MadelineProto/MTProto.php
+++ b/src/danog/MadelineProto/MTProto.php
@@ -603,20 +603,24 @@ class MTProto extends \Volatile
             if (strpos($id, 'media')) {
                 continue;
             }
+            $cdn = strpos($id, 'cdn');
             if ($socket->session_id === null) {
                 $socket->session_id = $this->random(8);
                 $socket->session_in_seq_no = 0;
                 $socket->session_out_seq_no = 0;
             }
             if ($socket->temp_auth_key === null || $socket->auth_key === null) {
-                if ($socket->auth_key === null) {
+                if ($socket->auth_key === null && !$cdn) {
                     \danog\MadelineProto\Logger::log(['Generating permanent authorization key for DC '.$id.'...'], Logger::NOTICE);
                     $socket->auth_key = $this->create_auth_key(-1, $id);
                 }
                 \danog\MadelineProto\Logger::log(['Generating temporary authorization key for DC '.$id.'...'], Logger::NOTICE);
                 $socket->temp_auth_key = $this->create_auth_key($this->settings['authorization']['default_temp_auth_key_expires_in'], $id);
-                $this->bind_temp_auth_key($this->settings['authorization']['default_temp_auth_key_expires_in'], $id);
-                $this->get_config($this->write_client_info('help.getConfig', [], ['datacenter' => $id]));
+                if (!$cdn) {
+                    $this->bind_temp_auth_key($this->settings['authorization']['default_temp_auth_key_expires_in'], $id);
+                    $this->get_config($this->write_client_info('help.getConfig', [], ['datacenter' => $id]));
+                    $this->get_cdn_config($id);
+                }
                 if (in_array($socket->protocol, ['http', 'https'])) {
                     $this->method_call('http_wait', ['max_wait' => 0, 'wait_after' => 0, 'max_delay' => 0], ['datacenter' => $id]);
                 }
@@ -637,7 +641,7 @@ class MTProto extends \Volatile
                 continue;
             }
             \danog\MadelineProto\Logger::log([$int_dc, $new_dc]);
-            if (preg_match('|_|', $new_dc)) {
+            if (strpos($new_dc, '_') !== false) {
                 continue;
             }
             \danog\MadelineProto\Logger::log(['Copying authorization from dc '.$authorized_dc.' to dc '.$new_dc.'...'], Logger::VERBOSE);
@@ -680,6 +684,16 @@ class MTProto extends \Volatile
         $this->config = empty($config) ? $this->method_call('help.getConfig', $config, $options) : $config;
         $this->parse_config();
     }
+    public function get_cdn_config($datacenter) {
+        /*
+         * ***********************************************************************
+         * Fetch RSA keys for CDN datacenters
+         */
+        foreach ($this->method_call('help.getCdnConfig', [], ['datacenter' => $datacenter])['public_keys'] as $curkey) {
+            $tempkey = new \danog\MadelineProto\RSA($curkey['public_key']);
+            $this->rsa_keys[$tempkey->fp] = $tempkey;
+        }
+    }
 
     public function parse_config()
     {
@@ -702,6 +716,10 @@ class MTProto extends \Volatile
             if (is_numeric($id)) {
                 $id = (int) $id;
             }
+            unset($dc['cdn']);
+            unset($dc['media_only']);
+            unset($dc['id']);
+            unset($dc['ipv6']);
             $this->settings['connection'][$test][$ipv6][$id] = $dc;
         }
         $this->datacenter->__construct($this->settings['connection'], $this->settings['connection_settings']);
@@ -709,7 +727,7 @@ class MTProto extends \Volatile
 
     public function getV()
     {
-        return 42;
+        return 44;
     }
 
     public function get_self()
diff --git a/src/danog/MadelineProto/MTProtoTools/AuthKeyHandler.php b/src/danog/MadelineProto/MTProtoTools/AuthKeyHandler.php
index 7343fa5e..9d3a1432 100644
--- a/src/danog/MadelineProto/MTProtoTools/AuthKeyHandler.php
+++ b/src/danog/MadelineProto/MTProtoTools/AuthKeyHandler.php
@@ -59,17 +59,6 @@ trait AuthKeyHandler
                     throw new \danog\MadelineProto\SecurityException('wrong nonce');
                 }
 
-                /*
-                * ***********************************************************************
-                * Fetch RSA keys for CDN datacenters
-                */
-                if (strpos($datacenter, 'cdn') !== false) {
-                    foreach ($this->method_call('help.getCdnConfig', [], ['datacenter' => $datacenter])['public_keys'] as $curkey) {
-                        $tempkey = new \danog\MadelineProto\RSA($curkey['public_key']);
-                        $this->rsa_keys[$tempkey->fp] = $tempkey;
-                    }
-                }
-
                 /*
                 * ***********************************************************************
                 * Find our key in the server_public_key_fingerprints vector
diff --git a/src/danog/MadelineProto/MTProtoTools/Crypt.php b/src/danog/MadelineProto/MTProtoTools/Crypt.php
index e898fed2..d3c58ba2 100644
--- a/src/danog/MadelineProto/MTProtoTools/Crypt.php
+++ b/src/danog/MadelineProto/MTProtoTools/Crypt.php
@@ -36,10 +36,9 @@ trait Crypt
         return $cipher->encrypt($message);
     }
 
-    public function ctr_encrypt($message, $key, $iv, $length)
+    public function ctr_encrypt($message, $key, $iv)
     {
         $cipher = new \phpseclib\Crypt\AES(\phpseclib\Crypt\AES::MODE_CTR);
-        $iv .= $this->pack_signed_int($length);
         $cipher->setKey($key);
         $cipher->setIV($iv);
 
diff --git a/src/danog/MadelineProto/MTProtoTools/Files.php b/src/danog/MadelineProto/MTProtoTools/Files.php
index d533e7bf..01f3655d 100644
--- a/src/danog/MadelineProto/MTProtoTools/Files.php
+++ b/src/danog/MadelineProto/MTProtoTools/Files.php
@@ -294,32 +294,34 @@ trait Files
                     throw $e;
                 }
             }
-            if ($res['type']['_'] === 'storage.fileUnknown' && $res['bytes'] === '') {
+            if ($res['_'] === 'upload.fileCdnRedirect') {
+                $cdn = true;
+                $message_media['file_token'] = $res['file_token'];
+                $message_media['cdn_key'] = $res['encryption_key'];
+                $message_media['cdn_iv'] = $res['encryption_iv'];
+                $old_dc = $datacenter;
+                $datacenter = $res['dc_id'].'_cdn';
+                \danog\MadelineProto\Logger::log(['File is stored on CDN!'], \danog\MadelineProto\Logger::NOTICE);
+                continue;
+            }
+            if ($res['_'] === 'upload.cdnFileReuploadNeeded') {
+                \danog\MadelineProto\Logger::log(['File is not stored on CDN, requesting reupload!'], \danog\MadelineProto\Logger::NOTICE);
+                $this->method_call('upload.reuploadCdnFile', ['file_token' => $message_media['file_token'], 'request_token' => $res['request_token']], ['heavy' => true, 'datacenter' => $old_dc]);
+                continue;
+            }
+            if ($cdn === false && $res['type']['_'] === 'storage.fileUnknown' && $res['bytes'] === '') {
                 $datacenter = 1;
             }
-            while ($res['type']['_'] === 'storage.fileUnknown' && $res['bytes'] === '') {
+            while ($cdn === false && $res['type']['_'] === 'storage.fileUnknown' && $res['bytes'] === '') {
                 $res = $this->method_call('upload.getFile', ['location' => $message_media['InputFileLocation'], 'offset' => $offset, 'limit' => $part_size], ['heavy' => true, 'datacenter' => $datacenter]);
                 $datacenter++;
                 if (!isset($this->datacenter->sockets[$datacenter])) {
                     break;
                 }
             }
-            if ($res['_'] === 'upload.fileCdnRedirect') {
-                $cdn = true;
-                $message_media['file_token'] = $res['file_token'];
-                $message_media['cdn_key'] = $res['key'];
-                $message_media['cdn_iv'] = $res['iv'];
-                $datacenter = $res['dc_id'].'_cdn';
-                \danog\MadelineProto\Logger::log(['File is stored on CDN!'], \danog\MadelineProto\Logger::NOTICE);
-                continue;
-            }
-            if ($res['type']['_'] === 'upload.cdnFileReuploadNeeded') {
-                \danog\MadelineProto\Logger::log(['File is not stored on CDN, requesting reupload!'], \danog\MadelineProto\Logger::NOTICE);
-                $this->method_call('upload.reuploadCdnFile', ['file_token' => $message_media['file_token'], 'request_token' => $res['request_token']], ['heavy' => true, 'datacenter' => $datacenter]);
-                continue;
-            }
             if (isset($message_media['cdn_key'])) {
-                $res['bytes'] = $this->encrypt_ctr($res['bytes'], $message_media['cdn_key'], $message_media['cdn_iv'], $offset);
+                $ivec = substr($message_media['cdn_iv'], 0, 12).pack('N', $offset >> 4);
+                $res['bytes'] = $this->ctr_encrypt($res['bytes'], $message_media['cdn_key'], $ivec);
             }
             if (isset($message_media['key'])) {
                 $res['bytes'] = $ige->decrypt($res['bytes']);
@@ -341,7 +343,6 @@ trait Files
             if ($theend) {
                 break;
             }
-            //\danog\MadelineProto\Logger::log([$offset, $size, ftell($stream)], \danog\MadelineProto\Logger::ULTRA_VERBOSE);
             if ($end !== -1) {
                 $cb($percent = $downloaded_size * 100 / $size);
             }
diff --git a/src/danog/MadelineProto/MTProtoTools/MsgIdHandler.php b/src/danog/MadelineProto/MTProtoTools/MsgIdHandler.php
index 2faa7880..9ddddee8 100644
--- a/src/danog/MadelineProto/MTProtoTools/MsgIdHandler.php
+++ b/src/danog/MadelineProto/MTProtoTools/MsgIdHandler.php
@@ -35,7 +35,7 @@ trait MsgIdHandler
                 throw new \danog\MadelineProto\Exception('Given message id ('.$new_message_id.') is not divisible by 4.');
             }
             if (!\danog\MadelineProto\Logger::$has_thread && $new_message_id->compare($key = $this->get_max_id($aargs['datacenter'], false)) <= 0) {
-                throw new \danog\MadelineProto\Exception('Given message id ('.$new_message_id.') is lower than or equal than the current limit ('.$key.').', 1);
+                throw new \danog\MadelineProto\Exception('Given message id ('.$new_message_id.') is lower than or equal to the current limit ('.$key.').', 1);
             }
             if (count($this->datacenter->sockets[$aargs['datacenter']]->outgoing_messages) > $this->settings['msg_array_limit']['outgoing']) {
                 reset($this->datacenter->sockets[$aargs['datacenter']]->outgoing_messages);
@@ -54,11 +54,11 @@ trait MsgIdHandler
             $key = $this->get_max_id($aargs['datacenter'], true);
             if ($aargs['container']) {
                 if ($new_message_id->compare($key = $this->get_max_id($aargs['datacenter'], true)) >= 0) {
-                    \danog\MadelineProto\Logger::log(['WARNING: Given message id ('.$new_message_id.') is bigger than or equal than the current limit ('.$key.').'], \danog\MadelineProto\Logger::WARNING);
+                    \danog\MadelineProto\Logger::log(['WARNING: Given message id ('.$new_message_id.') is bigger than or equal to the current limit ('.$key.').'], \danog\MadelineProto\Logger::WARNING);
                 }
             } else {
                 if ($new_message_id->compare($key = $this->get_max_id($aargs['datacenter'], true)) <= 0) {
-                    \danog\MadelineProto\Logger::log(['WARNING: Given message id ('.$new_message_id.') is lower than or equal than the current limit ('.$key.').'], \danog\MadelineProto\Logger::WARNING);
+                    \danog\MadelineProto\Logger::log(['WARNING: Given message id ('.$new_message_id.') is lower than or equal to the current limit ('.$key.').'], \danog\MadelineProto\Logger::WARNING);
                 }
             }
 
diff --git a/tests/testing.php b/tests/testing.php
index 72b82cff..1ca18a5f 100755
--- a/tests/testing.php
+++ b/tests/testing.php
@@ -31,7 +31,7 @@ if (file_exists('.env')) {
 
 echo 'Loading settings...'.PHP_EOL;
 $settings = json_decode(getenv('MTPROTO_SETTINGS'), true) ?: [];
-
+var_dump($settings);
 if ($MadelineProto === false) {
     echo 'Loading MadelineProto...'.PHP_EOL;
     $MadelineProto = new \danog\MadelineProto\API($settings);