Sponsored Content
Top Forums Shell Programming and Scripting Appending crontab using ssh and sudo without root credentials Post 302996205 by Corona688 on Friday 21st of April 2017 11:52:53 AM
Old 04-21-2017
sshpass is extremely insecure, because the password is passed as a parameter. This gives an opportunity for it to be intercepted.

This is the reason for plain ssh's "annoying" limitation of only accepting passwords from a terminal, and why you had to install a third party utility to do this.

sudo has the same limitation - it will not accept a password from 'echo password'. su also has the same limitation, in fact, any sane authentication system will have the same limitation. Password authentication means typed-in-realtime-by-a-human authentication and no substitutions for human are acceptable.

I suggest using ssh keys for noninteractive authentication for ssh, and also suggest configuring sudo for passwordless operation so you don't have to kludge a password into it.

Last edited by Corona688; 04-21-2017 at 12:58 PM..
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Possible to give non root user sudo to "crontab -l"

Does anyone know if this is possible? I want to give some users access to root's crontab but only with a read privilege. Is this possible to do or can only root or people with full root sudo view root's cron? (4 Replies)
Discussion started by: LordJezoX
4 Replies

2. AIX

make a mksysb without root credentials

dears, good day. i need to be able to take a mksysb for a machine running aix 6.1.5 without the root credentials and also without using sudo any advice ? (2 Replies)
Discussion started by: islam.said
2 Replies

3. Shell Programming and Scripting

Cron job initiating ssh AND sudo (from user, not root)

I've been bashing my head on the desk for 2 days trying to get this to work, but I've had no luck. I'll try to be as clear as possible in my explanation without dragging out the details. I'm trying to set up a cron job for user "john" which runs a script. This script initiates an ssh connection to... (5 Replies)
Discussion started by: eh3civic
5 Replies

4. Shell Programming and Scripting

ssh foo.com sudo command - Prompts for sudo password as visible text. Help?

I am writing a BASH script to update a webserver and then restart Apache. It looks basically like this: #!/bin/bash rsync /path/on/local/machine/ foo.com:path/on/remote/machine/ ssh foo.com sudo /etc/init.d/apache2 reloadrsync and ssh don't prompt for a password, because I have DSA encryption... (9 Replies)
Discussion started by: fluoborate
9 Replies

5. UNIX for Dummies Questions & Answers

Sudo to delegate permission from non-root user to another non-root user

I've been through many threads before i decide to create a separate thread. I can't really find the solution to my (simple) problem. Here's what I'm trying to achieve: As "canar" user I want to run a command, let's say "/opt/ocaml/bin/ocaml" as "duck" user. The only to achieve this is to... (1 Reply)
Discussion started by: canar
1 Replies

6. UNIX for Dummies Questions & Answers

sudo on becoming root

Anyone able to explain why if i run "sudo -i" or "sudo -s" i am able to get into root by just keying my own password? How to avoid this from happening coz i need all the users to use su - only. (2 Replies)
Discussion started by: timmywong
2 Replies

7. SuSE

Auditors want more security with root to root access via ssh keys

I access over 100 SUSE SLES servers as root from my admin server, via ssh sessions using ssh keys, so I don't have to enter a password. My SUSE Admin server is setup in the following manner: 1) Remote root access is turned off in the sshd_config file. 2) I am the only user of this admin... (6 Replies)
Discussion started by: dvbell
6 Replies

8. Red Hat

Sudo to user other than root but do not allow sudo to root

I have a set of RHEL 5 boxes running our ERP software on Oracle databases. I need to allow my DBA's to su to oracle and one other account (banner) without knowing the oracle or banner password. But I need to prevent them from su'ing to any other user especially root. I only want them to be able to... (1 Reply)
Discussion started by: westmoreland
1 Replies

9. UNIX for Beginners Questions & Answers

Sudo to root, but keep my own aliases?

I have a coworker that has set up some funky aliases in /etc/bash.alias, and he insists on leaving them that way. For example he aliased "ll" to "ls -lahtr", which really bugs me. Anyway, I was wondering if there were a way for me to sudo to root without reading /etc/bash.alias, or maybe have... (6 Replies)
Discussion started by: paqman
6 Replies

10. UNIX for Beginners Questions & Answers

How to check via SSH and credentials if file on remote server exists?

Hi there, I am sorry to ask that kind of beginner thing, but all the code I found online didnt work for me. All I want to do is: Check via SSH if a File exists on my webserver. The SSH login has to be with username and password. So I would be very thankful if somebody could write the line.... (8 Replies)
Discussion started by: Jens885544
8 Replies
pam_ssh_agent_auth(8)							PAM						     pam_ssh_agent_auth(8)

PAM_SSH_AGENT_AUTH
       This module provides authentication via ssh-agent.  If an ssh-agent listening at SSH_AUTH_SOCK can successfully authenticate that it has
       the secret key for a public key in the specified file, authentication is granted, otherwise authentication fails.

SUMMARY
/etc/pam.d/sudo: auth sufficient pam_ssh_agent_auth.so file=/etc/security/authorized_keys /etc/sudoers: Defaults env_keep += "SSH_AUTH_SOCK" This configuration would permit anyone who has an SSH_AUTH_SOCK that manages the private key matching a public key in /etc/security/authorized_keys to execute sudo without having to enter a password. Note that the ssh-agent listening to SSH_AUTH_SOCK can either be local, or forwarded. Unlike NOPASSWD, this still requires an authentication, it's just that the authentication is provided by ssh-agent, and not password entry. ARGUMENTS
file=<path to authorized_keys> Specify the path to the authorized_keys file(s) you would like to use for authentication. Subject to tilde and % EXPANSIONS (below) allow_user_owned_authorized_keys_file A flag which enables authorized_keys files to be owned by the invoking user, instead of root. This flag is enabled automatically whenever the expansions %h or ~ are used. debug A flag which enables verbose logging sudo_service_name=<service name you compiled sudo to use> (when compiled with --enable-sudo-hack) Specify the service name to use to identify the service "sudo". When the PAM_SERVICE identifier matches this string, and if PAM_RUSER is not set, pam_ssh_agent_auth will attempt to identify the calling user from the environment variable SUDO_USER. This defaults to "sudo". EXPANSIONS
~ -- same as in shells, a user's Home directory Automatically enables allow_user_owned_authorized_keys_file if used in the context of ~/. If used as ~user/, it would expect the file to be owned by 'user', unless you explicitely set allow_user_owned_authorized_keys_file %h -- User's Home directory Automatically enables allow_user_owned_authorized_keys_file %H -- The short-hostname %u -- Username %f -- FQDN EXAMPLES
in /etc/pam.d/sudo "auth sufficient pam_ssh_agent_auth.so file=~/.ssh/authorized_keys" The default .ssh/authorized_keys file in a user's home-directory "auth sufficient pam_ssh_agent_auth.so file=%h/.ssh/authorized_keys" Same as above. "auth sufficient pam_ssh_agent_auth.so file=~fred/.ssh/authorized_keys" If the home-directory of user 'fred' was /home/fred, this would expand to /home/fred/.ssh/authorized_keys. In this case, we have not specified allow_user_owned_authorized_keys_file, so this file must be owned by 'fred'. "auth sufficient pam_ssh_agent_auth.so file=/secure/%H/%u/authorized_keys allow_user_owned_authorized_keys_file" On a host named foobar.baz.com, and a user named fred, would expand to /secure/foobar/fred/authorized_keys. In this case, we specified allow_user_owned_authorized_keys_file, so fred would be able to manage that authorized_keys file himself. "auth sufficient pam_ssh_agent_auth.so file=/secure/%f/%u/authorized_keys" On a host named foobar.baz.com, and a user named fred, would expand to /secure/foobar.baz.com/fred/authorized_keys. In this case, we have not specified allow_user_owned_authorized_keys_file, so this file must be owned by root. v0.8 2009-08-09 pam_ssh_agent_auth(8)
All times are GMT -4. The time now is 06:50 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy