Display Usernames in an ssh network? - ssh

I'm trying to ssh into a network. When I get there, it prompts me for the password to the username I had entered with it. However, I don't remember my username.
Is there any way perhaps to look at all the usernames listed within a network like this? If I can do that, I can figure out which one is mine.

ssh by default will use the username of the account you're running it from. E.g. If you're logged into machine A as user 'xyz', then by default it'll transmit "username = xyz" to machine B when you try to ssh to it.
if you want to force a particular username, then use
ssh remoteusername#remotehost.com
If you've completely forgotten your remote username, then no... ssh will not scan the remote system and tell you what accounts are on it. That'd be a hideously BAD security hole.

Im not completely sure what you have and what you don't. If you know the password and are logged in, you can run the command whoami to know your username.

Related

Does bin/bash access allow the user to find the server password?

I had a server that had a lot of users on it, its operating system was cloudlinux and had cpanel!
This server is used for Python projects and had bin/bash!!! access
Suddenly the command rm -rf * was typed on the server and all the data was deleted !!!
We quickly uploaded the backups and hacked the possibility and restricted ssh access to the root server!
But the next night we were hacked again, this time with the monitoring we had at whm! , we noticed that someone enters whm and quickly changes the password !!!
My question is whether users with access to bin/bash! can find the root password ???
We are now giving users access to JailShell in CPanel and full SSH access is closed. Do you have any idea how this happened?
Did you encounter a similar case?
Does bin/bash access allow the user to see the password?
Thank you for sharing your comments with us
It's difficult to obtain a Linux password, even with full access to the computer. That's because the passwords are stored in hashed form. Probably the only reliable way to get a password is to install a trick password change program, which does the change, but also sends the password somewhere else.
However, you don't need the password to get full access to a computer. There are several other ways in, and anyone who can access /bin/bash is likely to be able to test them and probably find one that works. Once they get full access, most intruders will install some other program that will let them in in the future, even if the original security hole is patched.
Once a machine is compromised, it's pretty important to burn it and start fresh. You can't trust it otherwise.

Logging to remote server without specifying username

Today I configured ssh keys access to my server. Then I tested them and by mistake I forgot to specify the user, so instead of doing it like that:
ssh username#myserver.com
I did it like that
ssh myserver.com
but I successfully logged in as username. How is that possible? How does ssh server know under which user to log me in? If it's a key, than it's possible that I'll have the same key added to multiple users, what's going to happen in this case?
if you didn't include the username in the ssh command it will take the username that you logged in with from the environment, so there is two possibilities for what happened, 1. the username which is related to the ssh key is the username that you logged in with, or the other username that you logged in with has the his public key in the authorized_keys file in the server side

SSH config to restore user ssh access?

I have been locked out of ssh. I'm on the Google Cloud, so I can move the hd over and change the ssh config files, but after a few attempts, I cannot login still. The problem began shortly after I changed the password to the primary account, but since SSH was not using password authentication, I am surprised that affected SSH. I tried turning password authentication on, generating new keys, have Google's platform generate new keys, etc, but nothing has allowed me to log in.
I keep getting this error, regardless of key combo or whether or not password authentication is on.
Permission denied (publickey).
I have a slightly older backup (a couple hours, before the issue), and it's telling me too many authentication failures for any user (regarless of user#domain.com).
I was wondering if there are any config setting I can set to be able to log back in.
Not sure this belongs stackoverflow or serverfault but..
Try adding -vv to your ssh command. It shows a lot more debugging info
For example:
ssh -vv username#host
See if that gets you any hints! It could be a number of things, it searching for private key in the wrong place, etc.
The issue could be ssh keys saved in your local computer. Can you move the ssh keys from .ssh/ to a different directory in your local computer and see if that resolves the issue.
Or can you enable password authentication for your ssh and use -o flag with ssh command which forces non-key authentication to confirm if the issue was with the key: ssh -o PubkeyAuthentication=no username#
You also set MaxAuthTries to higher number in your sshd_config.

Batch | Net use Password

Sorry for my bad English, but if you can help my it will be great.
I have couple of file system over my network and every night I need to take one file from another file system to mine.
for that to happen i'm using a Batch script how mapping me the drive with net use command.
my problem is that i don't want the password will go through clear text
( To see my password or to sniff it).
my questions is :
there is any way that i can encrypt my password and still login with the same credentials.
Thank You
If you can set up a Domain controller using either one of your Windows machines, or Samba, then you could use Trusted authentication based on the user executing the scheduled job that executes the batch file.
Alternately, you could encrypt the password and have a program decrypt it and execute the net use, but you're always* going to be faced with the fact that if your computer can send the password out when you don't type it in, then your computer knows your password, and anyone with physical access to that computer can get your password.
*Unless your computer doesn't know the password, and instead relies on an HSM (Hardware Security Module).
I had the same thing but found a nice workaround.
The passwords are not stored in DOS so I went from the run menu and simply typed the name of the path like "\server\files".
When it asked for credentials I ticked the checkbox "Save credentials"
The password will then be stored in your Windows Credential Manager (control panel) and this way your dos batch file fwill always now the password.

In Subversion can I be a user other than my login name?

I'd like to know how to get Subversion to change the name that my changes appear under.
I'm just starting to use Subversion. I'm currently using it to version control code on an XP laptop where I'm always logged in under my wife's name. I'd like the subversion DB to show the changes under my name.
Later on I'll replicate the DB so it is accessible to the whole house. My wife uses the office computer where she is always logged in under my name. I'll probably set it up so that it automatically checks in modified documents... preferably under her name.
Eventually I'll probably be using it from a linux machine under another username.
Is there some way to modify the user environment to change the user name that Subversion calls you? I'd expect something like setting SVN_USERNAME='Mark' which would override however it usually gets the name.
Update: It looks like the --username flag that Michael referred to does work to change the name reported by "svn stat", even for local file: repositories. In addition, it is sticky so you don't need to specify it for the next command. I even rebooted and it still used the "--username" value from my previous boot.
Most Subversion commands take the --username option to specify the username you want to use to the repository. Subversion remembers the last repository username and password used in each working copy, which means, among other things, that if you use svn checkout --username myuser you never need to specify the username again.
As Kamil Kisiel says, when Subversion is accessing the repository directly off the file system (that is, the repository URL is of form file:///path/to/repo or file://file-server/path/to/repo), it uses your file system permissions to access the repository. And when you connect via SSH tunneling (svn+ssh://server/path/to/repo), SVN uses your FS permissions on the server, as determined by your SSH login. In those cases, svn checkout --username may not work for your repository.
For svn over ssh try:
svn list svn+ssh://[user_name]#server_name/path_to_repo
svn will prompt you for the user_name's password.
You can setup a default username via ~/.subversion/servers:
[groups]
yourgroupname = svn.example.com
[yourgroupname]
username = yourusername
Please be aware that older versions of svn do not support it (e.g. 1.3.1 [sic!]).
"svn co --username=yourUserName --password=yourpassword http://path-to-your-svn"
Worked for me when on another user account. You will be prompted to enter username/password again though. You need to login like the above once and you are all set for the subsequent times(Unless you restart your machine).
If you need to specify a username other than your logged in user for use with svn+ssh just add an entry to your .ssh/config file:
Host example.com
User jdoe
Subversion usually asks me for my "Subversion username" if it fails using my logged in username. So, when I am lazy (usually) I'll just let it ask me for my password and I'll hit enter, and wait for the username prompt and use my Subversion username.
Otherwise, Michael's solution is a good way to specify the username right off.
Most of the answers seem to be for svn+ssh, or don't seem to work for us.
For http access, the easiest way to log out an SVN user from the command line is:
rm ~/.subversion/auth/svn.simple/*
Hat tip: http://www.yolinux.com/TUTORIALS/Subversion.html
Using Subversion with either the Apache module or svnserve. I've been able to perform operations as multiple users using --username.
Each time you invoke a Subversion command as a 'new' user, your $HOME/.subversion/auth/<authentication-method>/ directory will have a new entry cached for that user (assuming you are able to authenticate with the correct password or authentication method for the server you are contacting as that particular user).
I believe if you use the file:// method to access your subversion repository, your changes are always performed under the user which accesses the repository. You need to use a method that supports authentication such as http:// or svn://.
See http://svnbook.red-bean.com/en/1.5/svn-book.html#svn.serverconfig.choosing
If you are using svn+ssh to connect to the repository then the only thing that authenticates you and authorizes you is your ssh credentials. EVERYTHING else is ignored. Your username will be logged in subversion exactly as it is established in your ssh connection. An excellent explanation of this is at jimmyg.org/blog/2007/subversion-over-svnssh-on-debian.html
Go to ~/.subversion/auth/svn.simple/*, and you will see a list of files that contains the information about your svn user account. Just delete all others that you don't need.
After that, when you do anything that regards to SVN operation, such as commit, rm, etc,. You will be prompt again to enter username or passwords.
TortoiseSVN always prompts for username. (unless you tell it not to)
I believe you can set the SVN_USER environment variable to change your SVN username.