Junos not accepting key authentication - authentication

I have a problem with ssh rsa key authentication. I'm using an SRX100H2 that is running JUNOS 12.1X46-D10.2. I generated a private/public key pair without password on an ubuntu host. I copied the public key in /var/tmp using scp on the SRX100H2 and committed the following changes:
user salvador {
uid 2001;
class super-user;
authentication {
ssh-rsa "ssh-rsa AAAA..."
}
}
I loaded the key with load-key-file command. The problem is I can't get authenticated. It's asking for the password every time, although the key has no password. I'm trying to use this account to run some script with fail2ban. To connect, I'm using:
ssh -i .ssh/name_of_the_key -l salvador x.x.x.x
I even went as far as modifying /var/etc/sshd_config on the SRX and added LogLevel DEBUG3, but for some reason it doesn't log so much information as a regular sshd linux daemon.
Is there a bug for this firmware version JUNOS 12.1X46-D10.2, or am I doing something wrong?
Thank you for your help.

I found a workaround. There is a python library named Junos PyEZ:
https://github.com/Juniper/py-junos-eznc
It can connect directly to a junos device using a username and password, without the need of an ssh key, and it can perform various configurations on the device. I managed to create a script that just adds an address in address book and adds that address in an address set that is applied to a security policy. This way the attacking host is banned and cannot access the exposed resources. The script is being run by fail2ban each time it is needed.

Related

Deploying with CircleCI - SSH into server requires password but I have SSH key associated

I am trying to SSH into the server as part of the deployment job in CircleCI
ssh -oStrictHostKeyChecking=no $DEV_DROPLET_USER#$DEV_DROPLET_IP
I have my SSH private key for the user on this server loaded into CircleCI but everytime I run the job, I get this output
Warning: Permanently added '$host' (ECDSA) to the list of known hosts.
<$user>#<$host>'s password:
How can I stop it prompting me for the password?
I have added the SSH key for this user to the SSH Agent on the server (these instructions)
For a passwordless ssh connection, you must:
put the private ssh key into a file in the directory $HOME/.ssh/ on the client computer connecting to the server (example : $HOME/.ssh/MyServer)
copy the public ssh key into the file $HOME/.ssh/authorized_keys on the server
have writing permission on the file $HOME/.ssh/known_hosts on the client computer
The sshd service is normally already configured to accept key based authentication.
From the client computer, you can now do a passwordless connection ssh -i $HOME/.ssh/MyServer $DEV_DROPLET_USER#$DEV_DROPLET_IP
Of course, on the client computer your $DEV_DROPLET_USER must have appropriate permissions for accessing the ssh related files.
You don’t need to do anything with the ssh agent, on the client or on the server.
Late reply, but I hope it helps somebody else in the future.
Assuming you followed these instructions in the CircleCI docs, then the private key will automatically be copied to the machine being used by CircleCI when the add_ssh_keys step is run.
Make sure one the server you are trying to SSH into, the public key generated (in ~/.ssh/id_rsa.pub or something similar) is copied to the ~/.ssh/authorized_hosts file on the same server. This crucial step is what allows anybody with the private key (CircleCI) to be allowed into the server.

SSH won't connect after asking about host authenticity

I'm having a problem; git returns this alert:
The authenticity of host 'bitbucket.org (104.192.143.2)' can't be established.
RSA key fingerprint is SHA256:zzXQOXSRBEiUtuE8AikJYKwbHaxvSc0ojez9YXaGp1
Are you sure you want to continue connecting (yes/no)?
When I choose yes, it returns this:
Warning: Permanently added 'bitbucket.org,104.192.143.2' (RSA) to the list of known hosts.
ssh_packet_read: Connection closed
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.
What is the problem?
Where must I add the RSA number? Please, I'm desperate. :(
The authenticity of host 'bitbucket.org (104.192.143.2)' can't be established. RSA key fingerprint is SHA256:zzXQOXSRBEiUtuE8AikJYKwbHaxvSc0ojez9YXaGp1 Are you sure you want to continue connecting (yes/no)?
This is normal and it's safe to say yes. ssh is being overly paranoid by asking you to confirm it. You can turn it off by setting StrictHostKeyChecking to no in your ssh config.
Remembering the public key of each server you connect to is a security feature of ssh to protect you from a man-in-the-middle attack. It goes something like this:
The first time you ssh to a host its public key (that's all that SHA256:zzXQ... stuff) is remembered, usually in ~/.ssh/known_hosts.
Every time thereafter ssh will check that the same host is still using the same key. This authenticates that bitbucket.org is still the same server you were talking to the first time.
If the keys don't match it could mean one of two things. First is that the server admin reinstalled their ssh server and forgot to keep the same key. This is common for small sites, but unlikely for something like bitbucket.org.
The second possibility is that the ssh server has been hijacked. It doesn't matter how. One common way is for a rogue DNS server to return their own malicious IP address instead of the real address for bitbucket.org. Common enough on public wifi connections.
As for why it won't connect after confirming, it's right there in the error message.
$ git clone git#bitbucket.org:RobeJablonski/sda-robert.git
Cloning into 'sda-robert'...
conq: repository access denied.
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.
The repository exists, that can be verified, so you don't have access rights (neither do I). Bitbucket determines who you are using your ssh key. This means you're not logging in with the right key. It has to be the same key as is associated with your account on BitBucket.
You can find your BitBucket ssh keys in your Bitbucket settings under https://bitbucket.org/account/user//ssh-keys/. Then you have to check if ssh is using that key. You can check what it's using using ssh -v git#bitbucket.org. It will spew out a lot of stuff but you're looking for the last instance of debug1: Offering RSA public key: /Users/blah/.ssh/blah.
Once you find that, check if /Users/blah/.ssh/blah.pub matches what BitBucket thinks your ssh key is. If they don't match, then you'll have to find the matching key and configure ssh to use that key for bitbucket.org.
If you've lost the key, you should change your ssh key on bitbucket.org.
Make sure you have followed below steps in your application server:
Have you created public key:
cd ~/.ssh/
To generate keygeneration:
ssh-keygen
Copy public key value (NOT PRIVATE KEY)
cat ~/.ssh/id_rsa.pub
Install git :
sudo apt install git
ATLASSIAN SETUP :
SETTINGS -> Access keys -> Add key
https://bitbucket.org/compassitesinc/your-repository/admin/access-keys/
Make sure your email address added to the User group (with admin permission)
SETTINGS -> User and group access
Add your email address with admin access
Inside your application root directory clone your repository.
cd /var/www/html/
git clone git#bitbucket.org:organization_name/repo_application.git repo_application
You need to create an SSH key on the machine you wish to connect to GitHub or Bitbucket, then add that key to your online account. You can do this by following this:
https://confluence.atlassian.com/bitbucket/set-up-ssh-for-git-728138079.html

Jenkins won't use SSH key

I'm sorry to have to ask this question, but I feel like I've tried every answer so far on SO with no luck.
I have my local machine and my remote server. Jenkins is up and running on my server.
If I open up terminal and do something like scp /path/to/file user#server:/path/to/wherever then my ssh works fine without requiring a password
If I run this command inside of my Jenkins job I get 'Host Key Verification Failed'
So I know my SSH is working correctly the way I want, but why can't I get Jenkins to use this SSH key?
Interesting thing is, it did work fine when I first set up Jenkins and the key, then I think I restarted my local machine, or restarted Jenkins, then it stopped working. It's hard to say exactly what caused it.
I've also tried several options regarding ssh-agent and ssh-add but those don't seem to work.
I verified the local machine .pub is on the server in the /user/.ssh folder and is also in the authorized keys file. The folder is owned by user.
Any thoughts would be much appreciated and I can provide more info about my problem. Thanks!
Update:
Per Kensters suggestion I did su - jenkins, then ssh server, and it asked me to add to known hosts. So I thought this was a step in the right direction. But the same problem persisted afterward.
Something I did not notice before I can ssh server without password when using my myUsername account. But if I switch to the jenkins user, then it asks me for my password when I do ssh server.
I also tried ssh-keygen -R server as suggested to no avail.
Try
su jenkins
ssh-keyscan YOUR-HOSTNAME >> ~/.ssh/known_hosts
SSH Slaves Plugin doesn't support ECDSA. The command above should add RSA key for ssh-slave.
Host Key Verification Failed
ssh is complaining about the remote host key, not the local key that you're trying to use for authentication.
Every SSH server has a host key which is used to identify the server to the client. This helps prevent clients from connecting to servers which are impersonating the intended server. The first time you use ssh to connect to a particular host, ssh will normally prompt you to accept the remote host's host key, then store the key locally so that ssh will recognize the key in the future. The widely used OpenSSH ssh program stores known host keys in a file .ssh/known_hosts within each user's home directory.
In this case, one of two things is happening:
The user ID that Jenkins is using to run these jobs has never connected to this particular remote host before, and doesn't have the remote host's host key in its known_hosts file.
The remote host key has changed for some reason, and it no longer matches the key which is stored in the Jenkins user's known_hosts file.
You need to update the known_hosts file for the user which jenkins is using to run these ssh operations. You need to remove any old host key for this host from the file, then add the host's new host key to the file. The simplest way is to use su or sudo to become the Jenkins user, then run ssh interactively to connect to the remote server:
$ ssh server
If ssh prompts you to accept a host key, say yes, and you're done. You don't even have to finish logging in. If it prints a big scary warning that the host key has changed, run this to remove the existing host from known_hosts:
$ ssh-keygen -R server
Then rerun the ssh command.
One thing to be aware of: you can't use a passphrase when you generate a key that you're going to use with Jenkins, because it gives you no opportunity to enter such a thing (seeing as it runs automated jobs with no human intervention).

Configuring SFTP in Pycharm

I'm trying to setup Pycharm such that my local changes are automatically deployed to a remote server.
I can ssh remoteserver and also sftp remoteserver from the terminal so access is not an issue. But if I try to setup deployment in Pycharm using SFTP, it can't establish the connection.
My best guess is that it's an authentication issue. When running the ssh or sftp commands separately, I've never needed to enter a username or password, so I suppose the auth is happening via Private Key. But the problem is that I'm not sure where the Private Key actually is (I'm in an unfamiliar dev environment).
So either
How do I know which Private Key I'm using when running ssh or sftp?
Any other way to resolve the problem.
Thanks!
As to (1), the SSH man page says (under the -i option) "The default is ~/.ssh/identity for protocol version 1, and ~/.ssh/id_rsa and ~/.ssh/id_dsa for protocol version 2. Identity files may also be specified on a per-host basis in the configuration file."
The configuration file is ~/.ssh/config, and the key file for a particular host is specified with IdentityFile.
You can also run ssh with -vvv parameter. The location of the private key file will be printed out (if key authentication is used).

SSH keys setup but still asking for password (but not for 2nd, 3rd, etc. sessions)

The target server is a relatively clean install of Ubuntu 14.04. I generated a new ssh key using ssh-keygen and added it to my server using ssh-copy-id. I also checked that the public key was in the ~/.ssh/authorized_keys file on the server.
Even still, I am prompted for a password every time I try to ssh into the server.
I noticed something weird however. After I log into my first session using my password, the next concurrent sessions don't ask for a password. They seem to be using the ssh key properly. I've noticed this behaviour on two different clients (Mint OSX).
Are you sure your SSH key isn't protected by a password? Try the following:
How do I remove the passphrase for the SSH key without having to create a new key?
If that's not the case, it may just be that ssh is having trouble locating your private key. Try using the -i flag to explicitly point out its location.
ssh -i /path/to/private_key username#yourhost.com
Thank you Samuel Jun for the link to help.ubuntu.com - SSH Public Key Login Troubleshooting !
Just a little caveat:
If you copy your authorized keys file outside your encrypted home directory please make sure your root install is encrypted as well (imho Ubuntu still allows for unencrypted root install coupled with encryption of the home directory).
Otherwise this defeats the whole purpose of using encryption in the first place ;)
If this is happening to you on Windows (I'm on Windows 10)
Try running the program that you're trying to connect via ssh to the server as administrator.
For me I was using powershell with scoop to install a couple of things so that I could ssh straight from it. Anyway... I ran PowerShell as admin and tried connecting again and it didn't ask for my password.
For LinuxSE
Check the SE context with
% ls -dZ ~user/.ssh
Must contain unconfined_u:object_r:ssh_home_t:s0
If not, that was the problem , as root run
# for i in ~user/.ssh ~user/.ssh/*
do
semanage fcontext -a -t ssh_home_t $i
done
# restorecon -v -R ~user/.ssh
It looks like it's related to encryption on your home directory and therefore the authorized_keys file cannot be read.
https://unix.stackexchange.com/a/238570
Make sure your ssh public key was copied to the remote host in the right format. If you open the key file to edit it should read 1 line.
Basically, just do ssh-copy-id username#remote. It will take care of the rest.