[X2Go-Commits] [x2goclient] 01/01: src/sshmasterconnection.cpp: fix compile errors on pre-libssh-0.6.0 systems and add a TOCTU-race check to see if the file exists prior to calling privatekey_from_file () on such systems.

[git-admin at x2go.org]

This is an automated email from the git hooks/post-receive script.

x2go pushed a commit to branch master
in repository x2goclient.

commit 2e90d7b33d563873b1221edb2eed756c5e186ebc
Author: Mihai Moldovan <ionic at ionic.de>
Date:   Mon Mar 6 12:49:16 2017 +0100

    src/sshmasterconnection.cpp: fix compile errors on pre-libssh-0.6.0 systems and add a TOCTU-race check to see if the file exists prior to calling privatekey_from_file () on such systems.
    
    Additionally fix a type issue.
---
 debian/changelog            |  4 ++++
 src/sshmasterconnection.cpp | 17 ++++++++++++++---
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/debian/changelog b/debian/changelog
index a1e1573..dc1fbbf 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -132,6 +132,10 @@ x2goclient (4.1.0.1-0x2go1) UNRELEASED; urgency=medium
     - src/sshmasterconnection.cpp: use new PKI-based libssh API for public key
       authentication for libssh 0.6.0 and higher. Fixes: #1119.
     - src/sshmasterconnection.cpp: add YubiKey challenge auth prompt.
+    - src/sshmasterconnection.cpp: fix compile errors on pre-libssh-0.6.0
+      systems and add a TOCTU-race check to see if the file exists prior to
+      calling privatekey_from_file () on such systems. Additionally fix a type
+      issue.
 
   [ Oleksandr Shneyder ]
   * New upstream version (4.1.0.1):
diff --git a/src/sshmasterconnection.cpp b/src/sshmasterconnection.cpp
index a97bbbf..8e620c2 100644
--- a/src/sshmasterconnection.cpp
+++ b/src/sshmasterconnection.cpp
@@ -1241,7 +1241,18 @@ bool SshMasterConnection::userAuthWithKey()
         priv_key = NULL;
     }
 #else
-    ssh_private_key priv_key = privatekey_from_file (my_ssh_session, tmp_ba.data (), NULL, NULL);
+    /* This is TOCTU, but forced upon us by libssh's legacy function. */
+    {
+      QFile tmp_file (keyName);
+      if (tmp_file.open (QIODevice::ReadOnly)) {
+        tmp_file.close ();
+      }
+      else {
+        /* Don't pass invalid files to privatekey_from_file () - it crashes in this case. */
+        return (false);
+      }
+    }
+    ssh_private_key priv_key = privatekey_from_file (my_ssh_session, tmp_ba.data (), 0, NULL);
 #endif
 
     int i=0;
@@ -1288,7 +1299,7 @@ bool SshMasterConnection::userAuthWithKey()
 #if LIBSSH_VERSION_INT >= SSH_VERSION_INT (0, 6, 0)
     if (SSH_OK != rc)
 #else
-    if (!prkey)
+    if (!priv_key)
 #endif
     {
 #ifdef DEBUG
@@ -1310,7 +1321,7 @@ bool SshMasterConnection::userAuthWithKey()
 #if LIBSSH_VERSION_INT >= SSH_VERSION_INT (0, 6, 0)
     if (SSH_OK != rc)
 #else
-    if (!pubkey)
+    if (!pub_key)
 #endif
     {
 #ifdef DEBUG

--
Alioth's /srv/git/code.x2go.org/x2goclient.git//..//_hooks_/post-receive-email on /srv/git/code.x2go.org/x2goclient.git