Type 3 (key Exchange Failed)

[Kaskuser Kiss]

I am writing an automated process to do connect to an SFTP site for downloading files. I am evaluating a trial version of Rebex SFTP for this. Using Visual Studio 2008, Visual Basic, I created a simple program that does this:

I can successfully connect to this SFTP site using Filezilla, answering Yes to the trust question. When I run my program, I get message "Key exchanged failed" on the connect command. I was kind of expecting to get a popup of some kind that asked me the same type of trust question that Filezila did, so that the key could be cached and re-used. I talked to the owner of the SFTP site. They sent me their public key and said I may need to load it on my PC and reference it in my application. But I don't know how to do this. I'd appreciate any help in getting this to work.

type 3 (key exchange failed)

Download ✔ https://urlgoal.com/2zSgy5

Looks like this SSH server is one of those that don't support RSA... In that case, remove the added code and replace your copy (all of them) of Rebex.Security.dll with this one. That should make Rebex SFTP work with 4096 "DSS" keys, even though it's an invalid size.

Choose the proper SSH key exchange method. SSH from FortiGate to other devices should work.

Related article:
Troubleshooting Tip: SSH error 'No matching host key type found' without any offer.

The Fortinet Security Fabric brings together the concepts of convergence and consolidation to provide comprehensive cybersecurity protection for all users, devices, and applications and across all network edges.

I receive the error "No matching host key type found" or "No matching key exchange method found" when connecting to my Amazon Elastic Compute Cloud (Amazon EC2) Linux instance using SSH. Short description

To resolve this error, make sure that the server and client having at least a single matching key exchange algorithm. Run the following command on the server and the client to check the key exchange algorithm:

I am trying to setup config backups for our OpenGear ACM7008 but SSH is failing with the error "Could not negotiate key exchange algorithm" screenshot attached. Then on the OpenGear syslog I get the error "Unable to negotiate with port 59619: no matching host key type found. Their offer: rsa-sha2-512,rsa-sha2-256,ssh-rsa,ssh-dss [preauth]". We are running Hybrid Cloud Observability Advanced version 2023.4.2. I tried recommended updates to the OpenGear SSH config file, added HostKeyAlgorithms =+ssh-rsa. Still get same error.

For the HPE we have to downgrade the key exchange to one that SolarWinds can do and with FortiOS that isn't a possibility so we are waiting on SolarWinds to update their end. I currently have a query in via our 'senior customer success manager' but so far I've had no update other than "we will coordinate internally and get back to you".

OpenSSH implements all of the cryptographic algorithms needed forcompatibility with standards-compliant SSH implementations, but sincesome of the older algorithms have been found to be weak, not all of themare enabled by default. This page describes what to do when OpenSSH refusesto connect with an implementation that only supports legacy algorithms.When an SSH client connects to a server, each side offers lists of connectionparameters to the other. These are, with the correspondingssh_config keyword:

• KexAlgorithms: the key exchange methods that are used to generateper-connection keys
• HostkeyAlgorithms: the public key algorithms accepted for an SSHserver to authenticate itself to an SSH client
• Ciphers: the ciphers to encrypt the connection
• MACs: the message authentication codes used to detect trafficmodification

For a successful connection, there must be at least onemutually-supported choice for each parameter.If the client and server are unable to agree on a mutual set of parametersthen the connection will fail. OpenSSH (7.0 and greater) will produce anerror message like this:Unable to negotiate with legacyhost: no matching key exchange method found.Their offer: diffie-hellman-group1-sha1In this case, the client and server were unable to agree on the keyexchange algorithm. The server offered only a single methoddiffie-hellman-group1-sha1. OpenSSH supports this method,but does not enable it by default because it is weak and within theoreticalrange of the so-called Logjam attack.Several related options come into play later during user authentication.

• PubkeyAcceptedKeyTypes (ssh/sshd): the public keyalgorithms that will be attempted by the client, and accepted by the serverfor public-key authentication (e.g. via .ssh/authorized_keys)
• HostbasedKeyTypes (ssh) and HostbasedAcceptedKeyTypes (sshd): the key types that will be attempted by the client, and accepted bythe server for host-based authentication (.e.g. via .rhosts or.shosts)

A mismatch between the client and server during authentication will causeauthentication to fail, despite it appearing to be configured. For example,an ssh-dss user key may be listed in.ssh/authorized_keys but may not pass authentication because,by default, sshd does not accept this key type.

Configures SSH to use a set of key exchange algorithm types in the specified priority order. The first key exchange type entered in the CLI is considered a first priority. Key exchange algorithms are used to exchange a shared session key with a peer securely. Each option represents an algorithm that is used to distribute a shared key in a way that prevents outside interference, manipulation, or recovery. Only the key exchange algorithms that are specified by the user are configured.

64591212e2