Questions tagged [ssh-keys]
an authorization mechanism for SSH involving public-key cryptography.
799
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SSH, remote host identification has change, local home network, not for all clients [closed]
I'm running a server (samba, ssh) on my local home network. Not accessible from the internet.
Today I received the message "Warning: Remote Host identification has changed". I receive it on ...
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1
answer
109
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ssh from CL using keyfile from Windows client to Linux server
This sort of thing drives me crazy - hopefully obvious solution(s). Have keys on Win 10 laptop, and on one of my Linux servers. If I use puTTY, where I can explicitly browse to the keyfile on the ...
0
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1
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258
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userauth_pubkey: signature algorithm ssh-rsa not in PubkeyAcceptedAlgorithms after upgrade of OpenSSH
After an upgrade I can no longer log in to my box (FreeBSD 14.0) using RSA key getting:
userauth_pubkey: signature algorithm ssh-rsa not in PubkeyAcceptedAlgorithms
in /var/logs/auth.log
on every ...
1
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0
answers
153
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Server host key changing frequently
Im trying to connect to my ubuntu server via ssh from Windows. Unlike my another ubuntu server from same dedicated server hosting, the server host key changing frequently.
I get WARNING: REMOTE HOST ...
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1
answer
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Is there a solution to manage users in some systems or at least in linux?
I work somewhere with a lot of Linux and VPS servers. When someone joins the company, other staff members need to add his SSH key to each server; conversely, if someone leaves, all of his SSH keys ...
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42
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Custom Linux AMI: How does AWS know where to install account SSH .PEM files when an AMI is provisioned?
We are building a custom AMI from a template EC2 EBS instance snapshot (Oracle Linux 8). This page shows there are many different user names depending on the AMI you choose:
https://docs.aws.amazon....
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1
answer
140
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Remote Linux server GitHub permission denied publickey issues
I am experiencing publickey permission issues when trying to pull a private repo from GitHub to a remote Linux server.
Update
Ran ssh -v -o IdentitiesOnly=yes -i ~/.ssh/id_rsa [email protected] command ...
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0
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119
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How safely obtain and check host public key for `known_hosts`?
For a newly deployed instance I get the following message for the first time SSH connection:
The authenticity of host '[hostname] ([IP address])' can't be established.
RSA key fingerprint is [key ...
10
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4
answers
4k
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How do I prevent users from messing with their own .ssh folder?
I'm administrating a RedHat server where users log in through SSH with private/pub key based authentication.
I'd like to prevent them from accidentally changing / deleting /chmoding the content of ...
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1
answer
428
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How to prevent OpenSSH from creating a new known_hosts file every time it updates it?
It seems that every time I accept a new host key, ssh (I've tested 8.6p1 and 9.3p2) does the following steps:
Move the known_hosts file to known_hosts.old;
Create a new known_hosts file;
Copy the ...
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126
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Can not SSH to GUI Ubuntu on Login Screen
I have a laptop with Ubuntu installed, and I've set up SSH using a key, and everything was working fine (I could SSH into the laptop from another computer).
Then, I rebooted the laptop, and on the ...
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2
answers
586
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How to remove all lines with the same public key from known_hosts?
Let's imagine the following scenario.
I have an host key ABCDEF1234 for a given hostname, so my known_hosts file looks like this (unhashed version):
example.com ssh-rsa ABCDEF1234
Now I connect to it,...
0
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1
answer
58
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Home directory, user database and key-based authentication
I want to share it NFS share with my users just like the home-directories (traditional way), but I don't want to create the users instead I want to get the server integrated with the github or google ...
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2
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the theory of SSH public and Private key and its application in realworld machines [closed]
there.
In this question, I have a very specific one about public and private keys. So Public keys should be put on the opposite side. For example, if we have a server, the public key of the server ...
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1
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160
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SSH tries other keys despite specifying a key with -i option
For the same user, I have two keys on the local machine. On the remote server, both keys are in the authorized_keys file.
I delete one of the keys in the authorized_keys file.
I then try to ssh with ...
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147
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SSH CA-signed key does not work from certain hosts
I've tried to setup CA signed ssh user keys.
I got my configuration working on most clients, there seems to be problem on a few specific ones.
The key verification fails and they are prompted for ...
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GCP VM instance not showing LESS keys as GCP editing instance metadata?
authorized_keys is missing AFTER I add my ssh key to an instance in GCP so then I connect via browser and authorized_keys is generated with 1. 'TWO keys'. I then click edit on instance and I see 2. '...
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2
answers
386
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How does SSH host verification for github.com provide any value?
Running git clone [email protected]/repo.git warns me of a potential man-in-the-middle attack when GitHub change their SSH key, and that's cool. I then get the new key by running ssh-keyscan -t rsa ...
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0
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249
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Linux server ssh connection wont authenticate my account using ssh key gen and prompts me for password
I am facing an issue in Ubuntu 22.04.2. where I am unable to SSH into a remote server using a copied public key. I have generated an SSH key pair on my local machine using a bash terminal, and I have ...
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1
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What is the host key (the one from ssh connection) and how is it different from public-private key pair?
The situation is that I've had a VPS created previously. It was all set up, private-public key authentication, root login turned off, password login turned off. Everything was set up.
Then this server ...
5
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0
answers
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What is the meaning of this line from ssh output: 'Authenticator provider $SSH_SK_PROVIDER did not resolve; disabling'?
Everything works, ssh connects using private-public ssh key pair.
Just few things in ssh -v Ora2 output isn't clear for me.
This is complete ssh -v Ora2 output:
PS C:\Users\roeslermichal> ssh -v ...
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1
answer
786
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Permission denied (publickey) error when managing GCP machine via Ansible (running on GCP VM) despite successful SSH connection
I deployed two machines to GCP via Terraform. Let's call them control-host and target-host. I want to manage the target-host via Ansible installed on the control-host.
Unfortunately, I keep getting ...
4
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2
answers
3k
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Why I can not ssh to my Vagrant host? [email protected]: Permission denied (publickey)
I created 5 VMs for my project
vagrant status
Current machine states:
master-1 running (virtualbox)
master-2 running (virtualbox)
master-3 running (...
0
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1
answer
40
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SSH key for 2 client users to 1 server user
If this is a duplicate, I'm sorry.
I have searched my case but I couldn't find the right scenario that resembles my situation, although I thought that this situation must have come up before for ...
1
vote
1
answer
478
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Validate all public keys in authorized_file
In my authorized_file i have multiple public keys against one private key. Now i want to add a task in ansible which will validate that all public keys are valid keys and good for connection. My aim ...
2
votes
2
answers
775
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Avoid SSH AgentForwarding of incompatible keys
Good morning,
I have one ed25519-sk key (using a hardware token), which I need only on my personal machine for some high security servers (all Debian). This key type is supported by OpenSSH 8.3+. We ...
0
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1
answer
486
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sshd not providing ecdsa/ed25519 host key algos
we have setup'd a bastion that only responds with the ssh-rsa host key algorithm when querying:
ssh-keyscan bastion.ops.dev.xxx.com
# bastion.ops.dev.xxx.com:22 SSH-2.0-OpenSSH_7.4
# bastion.ops.dev....
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1
answer
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Adding my SSH key to new user with only SSH access through key
I'm quite new to this, and I've looked through questions but haven't found one that quite matches my problem, or rather I didn't sufficiently understand them to be able to solve this issue.
I have a ...
0
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0
answers
886
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ssh illegal option while trying to connect to remote server
trying to ssh from my macbook pro, to a remote server,
ssh ayan@ServerIPAddress
gives the following error
ssh: illegal option -- ?
usage: ssh [-46AaCfGgKkMNnqsTtVvXxYy] [-B bind_interface]
...
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1
answer
308
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Needs a clarification for the ssh-copy-id command
Say I have two computers connected to the same Wifi network. Let's call them computer-A & computer-B.
I am using computer-A, I can ping computer-B without issues.
Now, on computer-A, I have ...
2
votes
1
answer
123
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User account auto-creation using SSH certificate authentication
My SSH server is configured to use certificate authentication, so it will trust anyone who presents a certificate issued by the user CA when they connect.
For reasons related with audit logs, I don't ...
0
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1
answer
75
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Install SSH key in an account that has no "usable" shell
A remote SSH server has a guest account with a known, non-blank password, that when logged in directly executes a text-based terminal game (not sure if via command, shell, or another method). The ...
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1
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Github Deploy Key Pattern
My Deployment Pattern
I have a setup as shown in the diagram above, where have a github account which owns a number of private repositories. I have a number of machines in the field that each include ...
2
votes
1
answer
313
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Use OpenSSH to make a key exchange with NTRU Prime
I would like to make a key exchange for a symmetric key from the client to the server with the NTRU Prime algorithm (for test reasons). I already installed OpenSSH 9.1 on both sides and checked ...
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3
answers
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Why the RHEL8 system do not generate SSH host keys automatically when missing?
On the RHEL 8 and previous it is usual, that the SSH host keys in /etc/ssh are generated automatically by sshd service when missing. Usually there should be:
/etc/ssh/ssh_host_ecdsa_key
/etc/ssh/...
6
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1
answer
3k
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How to ssh-copy-id through a jump-host? Something similar to the -J option with ssh command
I use a jump host to connect to the remote servers through SSH.
I use the following linear command for the connection.
ssh -J jumpuser@jumphost:2455 remoteuser@remotehost
It works fine.
But for new ...
0
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1
answer
75
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Cannot add passwordless private key with ssh-add on remote server
I can add a passwordless id_ed25519 file locally using ssh-add -k, but not on my remote server.
Locally:
☁ ~ ssh-add -l
The agent has no identities.
☁ ~ ssh-add -k ~/.ssh/id_ed25519
Identity added:...
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1
answer
1k
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Why do i need to restrict permissions on a PEM key?
I have a .pem key file that i use to ssh to my ec2 server. I've moved this key file to an encrypted external SSD disk. This has caused the owner of the pem key to be set to 'everyone'.
When i try to ...
11
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2
answers
4k
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ssh how to allow a very limited user with no home to login with pubkey
I have a very restricted user in my ssh server created with --no-create-home and --shell /bin/false.
I know I can define authorized_keys file in sshd_configs for the user's public key. But how can I ...
1
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0
answers
807
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Connection closed by remote host when copying client public key to sftp server
I want to copy the client public keys for a container to a remote sftp server and after that attempt do some uploads to the server via bash script(the bash script will be invoked when the container ...
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1
answer
808
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back up and restore host ssh_keys using cloud init autoinstall ubuntu
I am trying to automate VM installations for ubuntu 22.04 using autoinstall,cloud-init, qcow2 and virt-install. When I am reinstalling the OS on the same qcow2 file, I have a script that is run in ...
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0
answers
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Tentative of shh->rsync to wrong IP; potential security risk?
I have set up a little RPI backup 'server' (with rpi OS) on my LAN. I use it to create a backup of my main personal machine data using rsync, and I reach it from outside my network through SSH (key-...
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2
answers
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After install last version on ubuntu server 22 i can`t make ssh key connect to remote server
I did all the steps to create the key as I normally do:
ssh-keygen -t ed25519
next
ssh-copy-id -i /home/derbauer/.ssh/id_rsa.pub -p 12122 [email protected]
here everything goes normally
But in the ...
3
votes
3
answers
880
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Administrative access to a server via SSH key
Is it a good idea to set the SSH key directly for the root user for administrative access to a server?
Or is it better to use another user for SSH access via SSH key, followed by sudo command?
Is the ...
0
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1
answer
2k
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SSH Permission denied (public key)
I am trying to create my own SSH key to connect from one VM A to another VM B (both are Debian/bullseye64 systems).
Both VMs are configured to be on a public network using vagrant on my system with A ...
0
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1
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143
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Pull ssh key from github server
Many users have their own public ssh keys on github. Is there an easy way to get it knowing someone else's username?
I know it's possible - the ubuntu installer gets the keys somehow - but I can't ...
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1
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2k
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SSH permission denied
I have problem logging using ssh to company server.
I have my local ~/.ssh/config;
Host target
HostName xx.yy.zzz.aaa
User abcd
IdentityFile ~/.ssh/id_ed25519
IdentitiesOnly=yes
I have other ...
2
votes
1
answer
3k
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SSH2 fails authentication with a working key converted with PuttyGen (due to deprecated ssh-rsa?)
I have an EC2 instance authenticated with a key-pair generated by AWS.
With Putty, I can connect to the instance by providing the private key in a PPK file.
When I try to use SSH2 (via one of the ...
1
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0
answers
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no passphrase asked on copied ssh-key
I used an id_ed25519 key on a Debian Bullseye to connect to our remote servers, which had a passphrase. My laptop crashed so I recovered the key from a backup and started using it on an Ubuntu 22.04.
...
1
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1
answer
491
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Ansible file lookup works for debug, but doesn't work for authorized_key module — how to implement taking key from a file?
I am trying to build a playbook which includes distributing authorized SSH keys.
Each user's key is put into its own file named after the username. Users who need to be distributed are set in the ...