IT Security Stack Exchange
IT Security Stack Exchange

Questions tagged [openssh]

A free and open implementation of the SSH communication security tools.

A free and open implementation of the SSH communication security tools.

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178 questions
4
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1 answer

OpenSSH: Is setting a long ForwardX11Timeout better than ForwardX11Trusted?

I've never loved the idea of trusted X11 connections to shared machines. However, several years ago, we noticed that untrusted connections stopped working after a very short amount of time. After some digging, I found out that there's a…
Nate
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1 answer

ssh-keygen fingerprint format is different between RSA+ECDSA and ED25519

I noticed that when showing the fingerprint of different key types, there is one difference in the format. for some reason ED25519 has the hash bits (I guess?) - 256, whereas the other key types have the key length in bits instead. As you can see in…
Roy Ca
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2 answers

OpenSSH Disabling Diffie-Hellman (DHE) key exchange

I'm seeking to mitigate CVE-2002-20001 by disabling DHE key exchange through OpenSSH on an Ubuntu instance. I understand this can be achieved through editing the /etc/ssh/sshd_config at line KexAlgorithms…
user281564
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1 answer

OpenSSH Primes - can there be such a thing as "too few" primes available?

The (old) Secure Secure Shell guide suggests (re)creating /etc/ssh/moduli so sshd has safe prime numbers to use for Diffie-Hellman key agreement. I've generated a 4096-bit moduli file with ssh-keygen -G -b 4096, and then filtered them with…
mgarciaisaia
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1 answer

Configuration option PubkeyAcceptedKeyTypes vs PubkeyAcceptedAlgorithms?

I'm using OpenSSH 8.9p1. I'm trying to connect to a git via SSH, and I'm getting no matching host key type found. Their offer: ssh-rsa I was able to fix the problem by adding the following to my ~/.ssh/config Host git.host.net User git …
Evan Carroll
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tools for testing ssh packets size

I need to test maximum-packet-size for SSH protocol. Would be grateful for information on possible tools that can be used for this. What I specifically need is the possibility to indicate packet length and to insure that data was send as one packet.…
Antonina
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1 answer

Besides intended usage, what is the difference between a host key and a user key?

The ssh-keygen program has -h flag for creating a host key. What is the actual difference between keys created with and without -h? Is there any reason I could/should not use a host key as a user key or vice versa?
Keith Wolters
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