From 96eb1f379797bca03452f2bec33315dd4d289bd4 Mon Sep 17 00:00:00 2001
From: terrafrost <terrafrost@php.net>
Date: Fri, 5 Dec 2014 22:01:39 -0600
Subject: [PATCH] SSH2: simplify _send_channel_packet

the last _send_channel_packet was unnecessarily complex. this lead
to a number of problems. for example,

the window size was checked for adjustments in two places. in the
second place it receives a window adjustment packet and just assumes
that the window adjustment packet was big enough for the rest of the
data.

(thanks, pixall!)
---
 phpseclib/Net/SSH2.php | 42 ++++++++++++------------------------------
 1 file changed, 12 insertions(+), 30 deletions(-)

diff --git a/phpseclib/Net/SSH2.php b/phpseclib/Net/SSH2.php
index c904e678..ac095110 100644
--- a/phpseclib/Net/SSH2.php
+++ b/phpseclib/Net/SSH2.php
@@ -3275,27 +3275,23 @@ class Net_SSH2
      */
     function _send_channel_packet($client_channel, $data)
     {
-        /* The maximum amount of data allowed is determined by the maximum
-           packet size for the channel, and the current window size, whichever
-           is smaller.
-
-           -- http://tools.ietf.org/html/rfc4254#section-5.2 */
-        $max_size = min(
-            $this->packet_size_client_to_server[$client_channel],
-            $this->window_size_client_to_server[$client_channel]
-        );
-        while (strlen($data) > $max_size) {
+        while (strlen($data)) {
             if (!$this->window_size_client_to_server[$client_channel]) {
                 $this->bitmap^= NET_SSH2_MASK_WINDOW_ADJUST;
                 // using an invalid channel will let the buffers be built up for the valid channels
-                $output = $this->_get_channel_packet(-1);
+                $this->_get_channel_packet(-1);
                 $this->bitmap^= NET_SSH2_MASK_WINDOW_ADJUST;
-                $max_size = min(
-                    $this->packet_size_client_to_server[$client_channel],
-                    $this->window_size_client_to_server[$client_channel]
-                );
             }
 
+            /* The maximum amount of data allowed is determined by the maximum
+               packet size for the channel, and the current window size, whichever
+               is smaller.
+                 -- http://tools.ietf.org/html/rfc4254#section-5.2 */
+            $max_size = min(
+                $this->packet_size_client_to_server[$client_channel],
+                $this->window_size_client_to_server[$client_channel]
+            );
+
             $temp = $this->_string_shift($data, $max_size);
             $packet = pack('CN2a*',
                 NET_SSH2_MSG_CHANNEL_DATA,
@@ -3303,27 +3299,13 @@ class Net_SSH2
                 strlen($temp),
                 $temp
             );
-
             $this->window_size_client_to_server[$client_channel]-= strlen($temp);
-
             if (!$this->_send_binary_packet($packet)) {
                 return false;
             }
         }
 
-        if (strlen($data) >= $this->window_size_client_to_server[$client_channel]) {
-            $this->bitmap^= NET_SSH2_MASK_WINDOW_ADJUST;
-            $this->_get_channel_packet(-1);
-            $this->bitmap^= NET_SSH2_MASK_WINDOW_ADJUST;
-        }
-
-        $this->window_size_client_to_server[$client_channel]-= strlen($data);
-
-        return $this->_send_binary_packet(pack('CN2a*',
-            NET_SSH2_MSG_CHANNEL_DATA,
-            $this->server_channels[$client_channel],
-            strlen($data),
-            $data));
+        return true;
     }
 
     /**