search for: kexs

In sshconnect.c there are two global variables for server_version_string client_version_string. These are used just in a few functions and can easily be passed as parameters. Also, there is a strange construct, where their memory is allocated to the global pointers, then copies of these pointers are assigned to the kex structure. The kex_free finally frees them via cleanup of the kex

Hello everyone.. I am fairly new to the patching format.. so I just decided to post a basic info about how to remove group1 and group14 diffie key exchange in OpenSSH. I know that they are listed as required in RFC 4253 but I don't want a client to have the choice to use a 1024 bit prime for the key exchange. If someone is getting into my system.. they should upgrade to a new client. I am a

Dear OpenSSH developers, I've worked this week on an alternative key exchange mechanism, in reaction to the whole NSA leaks and claims over cryptographic backdoors and/or cracking advances. The key exchange is in my opinion the most critical defense against passive eavesdropping attacks. I believe Curve25519 from DJB can give users a secure alternative to classical Diffie-Hellman (with fixed

Hi, About a year and a half ago I brought up the topic of encrypted hostkeys and posted a patch (http://marc.info/?l=openssh-unix-dev&m=132774431906364&w=2), and while the general reaction seemed receptive to the idea, a few problems were pointed out with the implementation (UI issues, ssh-keysign breakage). I've finally had some spare time in which to get back to this, and I've

On Fri, Jan 26, 2024 at 7:24?PM Jochen Bern <Jochen.Bern at binect.de> wrote: > On 25.01.24 14:09, Kaushal Shriyan wrote: > > I am running the below servers on Red Hat Enterprise Linux release 8.7 > > How do I enable strong KexAlgorithms, Ciphers and MACs > > On RHEL 8, you need to be aware that there are "crypto policies" > modifying sshd's behaviour,

On 25.01.24 14:09, Kaushal Shriyan wrote: > I am running the below servers on Red Hat Enterprise Linux release 8.7 > How do I enable strong KexAlgorithms, Ciphers and MACs On RHEL 8, you need to be aware that there are "crypto policies" modifying sshd's behaviour, and it would likely be the *preferred* method to inject your intended config changes *there* (unless they

If I am trying to build OpenSSH 6.6 with Kerberos GSSAPI support, do I still need to get Simon Wilkinson's patches? --- Scott Neugroschl | XYPRO Technology Corporation 4100 Guardian Street | Suite 100 |Simi Valley, CA 93063 | Phone 805 583-2874|Fax 805 583-0124 |

https://bugzilla.mindrot.org/show_bug.cgi?id=3663 Bug ID: 3663 Summary: KEX host signature length wrong since strict kex introduced Product: Portable OpenSSH Version: 9.6p1 Hardware: Other OS: Linux Status: NEW Severity: major Priority: P5 Component: sshd

Hi, mancha and me debugged a problem with OpenSSH 7.3p1 that was reported on the #openssh freenode channel. Symptoms were that this message was popping on the console during a busy X11 session: kex protocol error: type 7 seq 1234 I managed to reproduce the problem, it is related to the SSH_EXT_INFO packet that is send by the server every time it is sending an SSH_NEWKEYS packet, hence after

Hi, I'm currently trying to troubleshoot what appears to be a very subtle bug (most likely a race condition) in SPTPS that causes state to become corrupted during SPTPS key regeneration. The tinc version currently deployed to my production nodes is git 7ac5263, which is somewhat old (2014-09-06), but I think this is still relevant because the affected code paths haven't really changed

https://bugzilla.mindrot.org/show_bug.cgi?id=1486 Summary: Improperly used buffer during KEX Classification: Unclassified Product: Portable OpenSSH Version: 5.0p1 Platform: All OS/Version: All Status: NEW Severity: normal Priority: P2 Component: Miscellaneous AssignedTo: unassigned-bugs at

On Tue, 23 Jun 2015, Jakub Jelen wrote: > > On 05/29/2015 09:12 AM, Damien Miller wrote: > > Hi, > > > > OpenSSH 6.9 is almost ready for release, so we would appreciate testing > > on as many platforms and systems as possible. This release contains > > some substantial new features and a number of bugfixes. > Tested basic configuration on Fedora 22. With

https://bugzilla.mindrot.org/show_bug.cgi?id=2198 Bug ID: 2198 Summary: GSSAPIKeyExchange gssapi-keyex bug in kex.c choose_kex() Product: Portable OpenSSH Version: 6.4p1 Hardware: All OS: Linux Status: NEW Severity: normal Priority: P5 Component: Kerberos support

I'm in the process of updating my GSSAPI patches to the 2.9 release. However, I've run into a slight problem with managing to get user options to play nicely with the way that the kex code is now organised. With the GSS kex its possible for the user to specify whether they want to delegate their credentials to the server or not. This option is used only on the client side (and so is

Dear all, I am currently implementing an experimental key exchange (KEX) algorithm. Unlike current algorithms like DH, mine needs to be able to fail gracefully, and in case of failure, continue with whatever algorithm would have been negotiated if mine was not selected. My strategy for graceful failure is to remove my KEX algorithm from myproposal[KEX_DEFAULT_KEX] and to initiate a new key

Hello, since one currently (after the 9.6 release addressing terrapin with strict-kex) cant be sure that strict KEX mode is negotiated (it depends on the capabilities of the partner), and the mitigation for that is to disable most modern/alternative ciphers and MAC modes - I would suggest you offer the option to enforce strict-kex mode as a server config as well as a per-host config in the

Hey guys, My second post in the last few days (boy I'm active! ;)). We've had a few issues with SSH Secure Shell version 3.2.0 (build 267) and sftp and while trying to figure it out I noticed something in the debug output that I think should be brought to OpenSSH's attention. Ssh2Transport/trcommon.c:1518: All versions of OpenSSH handle kex guesses incorrectly. Does anyone know

On Sat, May 16, 2015 at 04:53:33PM +0100, Etienne Dechamps wrote: > I believe there is a design flaw in the way SPTPS key regeneration > works, because upon reception of the KEX message the other nodes will > send both KEX and SIG messages at the same time. However, the node > expects SIG to arrive after KEX. Therefore, there is an implicit > assumption that messages won't

https://bugzilla.mindrot.org/show_bug.cgi?id=2291 Bug ID: 2291 Summary: ssh -Q kex lists diffie-hellman-group1-sha1 twice Product: Portable OpenSSH Version: 6.7p1 Hardware: Other OS: Linux Status: NEW Severity: minor Priority: P5 Component: sftp-server Assignee:

Hello, I'm looking for your insight about the log below. We have an SFTP server (IBM Sterling File Gateway) and we're connecting from an OpenSSH SFTP client but something fails during KEX. Complete client-side debug output is below, but I believe the relevant part is: debug1: kex: server->client cipher: aes192-cbc MAC: hmac-sha1 compression: none debug1: kex: client->server