Questions tagged [key-authentication]

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482
votes
26answers
737k views

Why am I still getting a password prompt with ssh with public key authentication?

I'm working from the URL I found here: http://web.archive.org/web/20160404025901/http://jaybyjayfresh.com/2009/02/04/logging-in-without-a-password-certificates-ssh/ My ssh client is Ubuntu 64 bit 11....
388
votes
8answers
362k views

How to force ssh client to use only password auth?

If I use pubkey auth from e.g.: an Ubuntu 11.04 how can I set the ssh client to use only password auth to a server? (just needed because of testing passwords on a server, where I default log in with ...
222
votes
6answers
249k views

How to avoid being asked passphrase each time I push to Bitbucket

I set up my ssh stuff with the help of this guide, and it used to work well (I could run hg push without being asked for a passphrase). What could have happened between then and now, considering that ...
204
votes
1answer
194k views

How to list keys added to ssh-agent with ssh-add?

How and where can I check what keys have been added with ssh-add to my ssh-agent ?
75
votes
11answers
331k views

ssh_exchange_identification: Connection closed by remote host (not using hosts.deny)

I'm not using hosts.allow or hosts.deny, further more SSH works from my windows-machine (same laptop, different hard drive) but not my Linux machine. ssh -vvv root@host -p port gives: OpenSSH_6.6, ...
73
votes
3answers
12k views

Server admin sent me a private key to use. Why?

I'm supposed to be accessing a server in order to link a company's staging and live servers into our deployment loop. An admin over on their side set up the two instances and then created a user on ...
73
votes
3answers
64k views

How to specify key in SSHFS?

I've got a question that I've not been able to find an answer for. I have two computers, both of which run Ubuntu Linux 12.04. I have set up my first computer ("home") to be able to SSH into my second ...
68
votes
2answers
286k views

How to enable diffie-hellman-group1-sha1 key exchange on Debian 8.0?

I am unable to ssh to a server that asks for a diffie-hellman-group1-sha1 key exchange method: ssh 123.123.123.123 Unable to negotiate with 123.123.123.123 port 22: no matching key exchange method ...
61
votes
6answers
91k views

how to avoid ssh asking permission?

We are attempting to speed up the installation of oracle nodes for RAC installation. this requires that we get ssh installed and configured so that it doesn't prompt for a password. The problem is: ...
60
votes
2answers
20k views

Is it safe to give out my SSH public key for work?

I currently work remotely for a number of organizations which need me to access their servers regularly for maintenance and upgrades. Is it safe for me to add my RSA public SSH key to the .ssh/...
38
votes
2answers
45k views

Is there an easy way to update information in known_hosts when you know that a hosts key has changed?

If a host's operating system has been re-installed and had its public key regenerated sshing to it will of course fail because the new key doesn't match the old one. Is there an easier way to tell ...
34
votes
10answers
106k views

SSH public key won't send to server

I've been struggling with this for a couple hours so any help is greatly appreciated... I have 2x servers both of which I can ssh to with public keys from OSX, no issues at all there so I'm certain ...
27
votes
4answers
34k views

SSH asking for passphrase on public key with no passphrase set

I have been using public key authentication on my servers for a while now, but I am experiencing issues on a new 'client' trying to connect to github. I have read many threads to verify that my ...
25
votes
1answer
15k views

openssh: Have ssh add keys to agent as needed

When I ssh into a server and my key isn't loaded in the agent, I have to abort, then run ssh-add to get my key into the agent. I'd like the ssh command to add the key automatically if it isn't present,...
21
votes
2answers
126k views

SSH key-based authentication: known_hosts vs authorized_keys

I read about setting up ssh keys in Linux and have some questions. Correct me if I'm wrong… Let's say host tr-lgto wants to connect to host tr-mdm using ssh. If we want to be sure that it's the real ...
19
votes
3answers
38k views

Authentication refused: bad ownership or modes for file /var/git/.ssh/authorized_keys [duplicate]

EDIT The issue as exposed here is solved (about files modes of the .ssh folder. But an other issue persists so I create a new question : > Unable to login with SSH-RSA key I can no longer ...
19
votes
5answers
54k views

SCP from one server to another without password prompt

What is the best way of doing scp from one box to the other without prompting for password? There are two servers: Server A (10.152.2.10): /home/oracle/export/files.txt Server B (10.152.2.11): /home/...
16
votes
3answers
14k views

Is it possible to have 2 ports open on SSH with 2 different authentication schemes?

I'm currently trying to set up an SSH server so that access to it from outside the network is ONLY allowed using an SSH Key and does not allow access to root or by any other username/password ...
12
votes
4answers
4k views

How to make password-less login work

I generated a key and copied it to my target: ssh-keygen ssh-copy-id username@hostname I left the the location of the key as default and did not set any passphrase. For a small while after that, I ...
12
votes
2answers
2k views

A consistent and safe approach to passwordless accounts with SSH

I must admit that I like servers without passwords in some cases. A typical server is vulnerable to anyone who has physical access to it. So in some cases it is practical to lock it physically and ...
11
votes
2answers
6k views

Restrict password-less backup with SFTP

I need to perform backup of a server to my computer using Duplicity: duplicity /etc sftp://backup@my.dynamic.ip.address//home/backup Before this can be done, I need to allow password-less access by ...
10
votes
2answers
10k views

Multiple SSH private keys, possible?

Is it possible to have multiple SSH key in a single client, and let ssh choose the right one automatically?
10
votes
1answer
3k views

Given a private SSH key, how do I recover my public key?

I've somehow lost my id_rsa.pub file. I still have my id_rsa file. How do I recover the public key from the private key? (This question came up after ssh-copy-id was reporting "ERROR: No identities ...
10
votes
1answer
16k views

ssh into an account which has no home directory

As a follow up to my previous question, I have decided to create the local user accounts as below. adduser --system --no-create-home USERNAME Now, I would like the local users to be able to access ...
10
votes
3answers
1k views

How can I lock my own account from remote ssh login with password?

I don't want to disable remote login with password altogether, but I want to make it so that my account is only accessible with key pair authentication (there are other users who wants to use ...
9
votes
2answers
10k views

Send the password through stdin in `ssh-copy-id`

I need to automate some identity deployments, ideally using ssh-copy-id. I'm trying to provide the password through stdin, which is possible on ssh by using the -S flag. I'm aware that I can send ...
9
votes
2answers
4k views

Is it possible to use ssh-copy-id once password based logins are disabled?

Is it possible to use ssh-copy-id once password based logins are disabled? Otherwise, is there an utility for adding an authorized public key to a user or should I edit the ~/.ssh/authorized_keys file ...
9
votes
1answer
490 views

Is there a technical reason why ssh-agent lacks a sudo-like inactivity/idle timeout feature?

There are some brief discussions about the existing ssh-agent -t feature at [1], and there was a post as far back as 2001 on debian-devel [2] wishing for an inactivity timeout feature. There's a ...
8
votes
6answers
2k views

Allow regular users to SSH using a private key they cannot read

Let's say I have a set of machines (called here the customers' machines) that only a small list of people (called the support staff) is allowed to SSH into, using only one account by machine (the ...
8
votes
3answers
17k views

parallel-ssh with Passphrase Protected SSH Key

I'd like to use my passphrase protected SSH key when performing tasks with parallel-ssh (and related tools). However, I can't get this to work. All the documentation, regarding parallel-ssh, show ...
8
votes
1answer
7k views

How to point to ssh folder with private keys to automatically choose one?

I would like to be able to use ssh user@host without the -i identity_rsa_or_else_private_key_file . Is there a place somewhere in ssh configs where I can point where are the private keys located ...
7
votes
5answers
62k views

Permission denied (publickey,gssapi-keyex,gssapi-with-mic)

Ok, so I have tried this quite a few times and I'm sure this is very trivial but: I am trying to SSH via command line on Ubuntu into my VM (Centos6) with an RSA key-pair I created using key-gen. I ...
7
votes
4answers
5k views

Must I store a private key in a file?

I have a db-driven application that needs to communicate with another server via ssh. The web app can generate a keypair and give the user the pubkey, or it can accept the unencrypted private key in a ...
7
votes
1answer
15k views

How to convert SSH public key from PEM to DER format?

I'd like to convert an existing public key (generated using ssh-keygen) from PEM-format to DER-format I tried: openssl rsa -in ~/.ssh/id_rsa.pub -inform PEM -pubin -outform DER -out ~/.ssh/id_rsa....
6
votes
5answers
19k views

ssh prompts for password despite .ssh/authorized_keys

I issued ssh username@db2workgoup -n "echocat ~/.ssh/id_dsa.pub>> ~/.ssh/authorized_keys" and then checked that the key was stored in authorized_keys file. But ssh is still asking for the ...
6
votes
2answers
715 views

Is it possible to use one SSH key per account for each account on a given remote server?

Suppose I have a number of accounts on a server called SERVER. Let's call them ACCOUNT1, ACCOUNT2 and ACCOUNT3. Suppose I don't want to have to type in the password for the account each time I ssh ...
6
votes
6answers
45k views

SSH: “Server refused our key” with no reason

I was trying to set up a simple backup script to run automatically that would copy a file from a Windows machine to a Linux one through SSH. As a lot of simple online tutorials suggest I used pscp ...
6
votes
1answer
3k views

SSH Public key comment separator

I've created a SSH authentication key (with ssh-keygen) in two different servers, both with a useful comment, but the public key of one server has == between the key and the comment, while the other ...
6
votes
1answer
11k views

How to validate an SSH public key?

I've had issues copying public keys to authorized_keys and winding up with an extra linefeed or space or something. Is there a way to simply validate that a key looks like a valid key? I don't have ...
6
votes
3answers
832 views

Send an email any time an SSH key is used

I have about 30 nearly-identical CentOS 6 servers that I need to be able to push out updated config files automatically using an rsa key to log in as root. Usually this will just be rsync, but ...
6
votes
1answer
636 views

How do I stop ssh from offering other keys?

I have some server dev.example.com and in its authorized_keys file I have my ~/.ssh/id_rsa.pub key. I also have an ~/.ssh/my_test.pub key. My ~/.ssh/config specifies that for dev.example.com it ...
6
votes
1answer
2k views

SSH public keys not working; my home directory is encrypted

I installed Ubuntu LTS 14.04 server edition on a remote computer, and added my local public key to ~/.ssh/authorized_keys on the remote computer. I found that I still needed to use password to log in ...
6
votes
2answers
1k views

SSH password requested when in Tmux

When I connect to my remote machine I do authenticate using a rsa key (I think is rsa, don't remember). If I do ssh from a regular shell I get logged on the machine without a password. However if I ...
6
votes
1answer
1k views

How can I determine which SSH keyfile was used to authenticate a login?

We have a hosted CentOS 6.5 server in which we have a single user account. That account has been configured to use SSH keyfile authentication for the users who need to access it. I would like to be ...
5
votes
1answer
5k views

SSH Public Key authentication - works only after a physical login

I am trying to connect via SSH to my ubuntu server with public key authentication. For some reasons I get an "Permission denied (publickey)." on the client, whenever I execute ssh -i ~/.ssh/id_rsa &...
5
votes
3answers
2k views

Best way to distribute user's public SSH key to many hosts?

Obviously I could scp the key to every host the user needs SSH access to. But if there are many hosts this could take a long time. Especially if public key authentication is not set up yet, every scp ...
5
votes
1answer
922 views

SSH with Cron: RSA key not accepted

I am trying to get ssh to work in cron, and it seems like I have tried all the standard tricks with no luck at all. I can run a non-interactive ssh by using >./some_script_with_ssh in bash. It's ...
5
votes
1answer
3k views

How does OpenSSH determine the choose the host key algorithm?

After updating raspbian and all of its libraries I noticed something different about SSH. When I delete the 'known hosts' file in my home and ssh into my box it provides me with the hosts public key ...
5
votes
3answers
606 views

For a same unix or linux user, different sets of environment variables

I'm using tcsh, and for a specific project every member of my team connects to a server with the same user. (This is something we cannot change). The situation arises because I want to have some ...