SSH (Secure shell) is a protocol for secure communication between computers to execute remote commands, transfer data and tunnel TCP connections.

learn more… | top users | synonyms

-1
votes
0answers
36 views

How to reset an HSM server without password? [on hold]

I purchased an HSM online but I do not know the password. Is there a way to reset a HSM server?
1
vote
2answers
31 views

Public/private key auth and VPN

If a server uses public/private key authentication to access SSH, will there be any advantage of restricting the access of SSH over VPN? This link describes both approaches to solve brute force ...
9
votes
3answers
519 views

Can an attacker “simulate” a private IP address?

I have a SSH server with a rule that does not allow password connections outside the local network. So people already on the local network, either physically or via VPN, are allowed to connect with ...
3
votes
2answers
35 views

Security of nested ssh

First of all, by nested ssh, I mean the following way of using ssh: ssh usera@Bob 'ssh usera@C' suppose A wants to login on server C, but for some reason C is not directly available to A (e.g. C's ...
2
votes
1answer
39 views

Can you use ssh for secure inter app communication on the same device?

I use ssh to get an encrypted connection between servers and local machines all the time. It's fast, it's secure, and there's a way to do it in nearly every system programming language that I've used ...
2
votes
1answer
45 views

Will two virtual machines running on the same physical host machine get the same value from /dev/random?

Will two virtual machines running on the same physical host machine get the same value from /dev/random if read over the same time period? Say that Virtual-machine-1 wants to generate its ssh host ...
1
vote
1answer
32 views

Why does the server ssh public key not look like the key in client known hosts?

From my naive understanding of ssh, the server shares its public key ( /etc/shh/ssh_host_rsa_key.pub ) with the client, who then adds it to the list of known hosts ( /user/.ssh/known_hosts ). So, I ...
0
votes
2answers
55 views

Server compromised with magento vulnerability, possible rootkit

I am experiencing a security issue with one server that it happens that I manage. I will try to cite all relevant facts as briefly as possible. I am asking for any additional information and course of ...
2
votes
0answers
53 views

Convert RSA openSSH key/putty key to gpg key [closed]

Scenario Two work sites, site 1 and site 2. Two Linux servers, server A and server B. Server A is reachable from both sites, while server B is reachable from site 1 only. Two Windows workstations, ...
0
votes
0answers
11 views

RSA Fingerprints on EC2 Server Don't Match Locally Generated Fingerprint [migrated]

I have an EC2 instance with an elastic IP that hasn't changed in a little while, nor has the ssh key Amazon installed in the main user account used to ssh into the server after instantiation. I ...
2
votes
0answers
43 views

Does enabling VPN on our router increase the risk of our network being exposed to the outside network? [closed]

We are thinking about using VPN to connect our remote office and the main office and also support developers working from home. To do this, we are planning to purchase 2 CISCO (or similar) routers to ...
0
votes
0answers
61 views

Risks of having SSH private key stolen

I'm afraid this is quite a common question, but searching several times through the questions did not prove useful, and I'm really eager of knowledge here :D I understand that keeping SSH private key ...
4
votes
2answers
225 views

Sharing RSA keys between PGP and SSH protocols: Does this pose a security risk?

If I generate a PGP subkey that only has the authentication capablity and use this to generate an SSH keypair to authenticate Git for example, does this pose a security threat? When I do, should I ...
1
vote
1answer
107 views

Metasploit SSH Error: could not settle on kex algorithm

I am running a trial of Cobalt Strike which runs over the Metasploit Framework. I am trying to perform an SSH related attack on my laptop, and I get the error in the title for all SSH related attacks. ...
2
votes
0answers
46 views

chroot ssh users [closed]

I am using CentOS 7. I need to give shell access to ssh users but restrict them in a jail. I have used jailkit to set up the jail. I have copied all necessary libraries, binaries that are needed for ...
2
votes
1answer
198 views

SSH Key: Ed25519 vs RSA

A lot of people recommend using Ed25519 instead of RSA keys for SSH. The introduction page of Ed25519 (http://ed25519.cr.yp.to/) says: [..] breaking it has similar difficulty to breaking [..] RSA ...
3
votes
2answers
321 views

What stops an SSH server from MITMing logins?

When I read this question about what gets signed with the private key by the client I wondered: What stops the following scenario from happening: A client connects to an SSH server. The SSH server ...
1
vote
2answers
155 views

Break in attempts from secureserver.net

Over the last few weeks I have seen dozens if not hundreds of break-in attempts from ip addresses which map back to secureserver.net. I know these are GoDaddy machines from the who is look up. ...
2
votes
1answer
351 views

Are there any security implications in creating an SSH key for the root user?

I've written an install script on a server to quickly set up new sites in the /srv directory. It needs to do a git clone, and has to be run via sudo in order to have the permissions to do all the ...
4
votes
1answer
111 views

Analyzing log files for forensics homework?

Suppose two users have done a murder at 6pm at Dunkin Donuts, I have got the hard disks on site, disk1 and disk2. How do I identify the time and order of each user's activities on the hard disks? ...
1
vote
0answers
64 views

Logging all traffic crossing SSH proxy

Is there a way to log SSH sessions proxied through a machine (User-> SSH Proxy -> Server (with SSH)) without modifying the SSH daemon on the proxy? I need to log all the commands as well as responses ...
13
votes
3answers
578 views

Managing multiple SSH private keys for a team

I have a medium-sized team (~10 people, but we expect to grow) that manages a set of EC2 servers on AWS (currently a few dozens, but this is also expected to grow). As EC2 requires you to have an ...
2
votes
1answer
21 views

How is composed “public host key and certificates (K_S)” in SSH_MSG_KEX_DH_GEX_REPLY message? (SSH2 key exchange)

I'm trying to implement SSH2 key exchange in Java, and having some difficulties. The RFC4419 states, that: The server responds with: byte SSH_MSG_KEX_DH_GEX_REPLY string server public host ...
1
vote
1answer
61 views

SSH: What's the difference or interplay between /etc/ssh/[host files] and ~/.ssh/[public key]

I'm new to SSH after a decade of dabbling with Ubuntu and other Linux builds. Today I successfully setup SSH, but I had a few hangups and headaches along the way. Although the system is now running ...
2
votes
1answer
109 views

someone may be doing something nasty

I have an ssh server. earlier toady, I was about to login to my server, when I got a message that said something along the lines of "Someone may be trying to do something nasty" and indicating a man ...
1
vote
3answers
129 views

Sharing a common public and private SSH keys for a cluster of machines

I guess this is way to settle an internal debate I am having with myself. In my provisioning process, I am wanting to share a common public and private ssh keys for each machine in a clusters, ...
1
vote
2answers
42 views

How to handle disk encryption for remote connection?

I have at my workstation, an ubuntu 14.04 installation with full disk encryption. I now have to travel frequently for days and am planning to ssh into this machine from my chromebook to work remotely. ...
1
vote
1answer
39 views

Things to do to ensure that data is secured on my virtual server [closed]

I'm not much of a server administrator but I'm maintaining a virtual server with Ubuntu OS where my website is hosted. I often use ssh, ftp and MySQL. As my website gets popular, I want to make sure ...
2
votes
1answer
50 views

Using Google Authenticator for SSH sessions

So I have an SSH tunnel which I use with dynamic port forwarding to the alternate http port on the client. For initializing this connection, I'd like to implement an additional verification step, ...
2
votes
1answer
86 views

How to view all SSH authorized_keys for a unix server

How would I view all the authorised SSH clients from a unix server? I know that cat ~/.ssh/authorized_keys shows authorised keys if logged in from root. Can other users set their own authorised keys ...
1
vote
0answers
120 views

Metasploit ssh_enumusers stops instantly [closed]

When I try to run the : http://www.rapid7.com/db/modules/auxiliary/scanner/ssh/ssh_enumusers using the given options besides proxies I get the output: msf auxiliary(ssh_enumusers) > run [*] ...
0
votes
1answer
34 views

Custom publickey authentication

I'm working on a REST account management system over https that should support both username/password and username/publickey authentication schemes. I.e. when a user registers an account, they may ...
5
votes
1answer
67 views

Relationship between HTTPS and SSH Public Keys

I can use my private key to generate a public key for use with ssh. I can use the same private key to generate a CSR, to generate a CLIENT certificate for HTTPS. Specifically, my SSH public key is: ...
0
votes
1answer
48 views

Is it worth it to use sshguard when only allowing ssh login from specific IP?

I'm running a VPS (under ArchLinux) and was wondering if sshguard was useful in the following case. My iptables rule for SSH in looks like this : iptables -A INPUT -p tcp --source $Trusted --dport ...
33
votes
2answers
5k views

I accidentally published my SSH key passphrase, what to do?

So I mistook input fields and now my SSH key passphrase is visible to the world, and I can't even remove it. Now as far as I understand, this is not an immediate security concern, since the ...
2
votes
1answer
73 views

Do I have an SSH password?

I have an Ubuntu server hosted on DigitalOcean, I have been using SSH keys since the very beginning. (You can chose for it to be setup before the server instance has even been created). So I have ...
2
votes
2answers
173 views

Lots of SSH tries on my log. Is it normal?

I have a Raspberry Pi connected to my home and at day 2 of this month I've opened the port 22 of my router so I could SSH it from anywhere. Today by curiosity, I decided to see the raspberry pi log, ...
0
votes
1answer
87 views

Would the authorities in my college be able to see what websites I accessed through tunneling(SSH)?

I study at a college where most social networking sites are banned(Including this one) and if someone is found using them somehow is heavily fined.I just want to know what all can the network admin ...
2
votes
1answer
192 views

difference between public key and host key and security of host key

In SSH, what is the difference between host key and public key. Public key I believe that is part of private/public key pair, so, that anything sent by server(encrypted using private) can be ...
1
vote
1answer
94 views

Security of access to local network via VNC over SSH tunnel

I've just set up a Raspberry Pi 2 with the latest raspbian and installed some services. For remote access I've installed tightvnc server which I set up to only allow connections from localhost. I can ...
4
votes
2answers
95 views

Do GPG and OpenSSH use key stretching on their keypairs?

Both OpenSSH and GPG can generate key pairs which are stored as files in well-known paths inside the user directory. A passphrase is always asked for during the generation process, which is then used ...
1
vote
1answer
67 views

Choosing a cipher and MAC for an SSH connection

The cipher and mac selection according to this are in some sort of order in a config file. How do the client and server know that they are using the same ones though? Is this information exchanged in ...
5
votes
1answer
157 views

Is port forwarding inherently unsafe?

I had an argument with a person a few months ago when I proposed we forward port 12xyz to an internal SSH server. The target server was tied down in a manner similar to the one recommended by ...
2
votes
2answers
44 views

non-https winscp website

The whole point of WinSCP is to provide a secure channel between a computer and a server. "Secure" means that there is a possibility of an attacker that can view or modify bytes sent both ways. Let's ...
3
votes
1answer
107 views

How to deal with SSH keys in insecure environment

I am trying to find out a "safe" solution for the following situation. tl;dr how to keep things secure in an environment that is absolutely not? I work in a company where workstations are not safe ...
8
votes
1answer
178 views

RSA key generation: gpg vs openssh

When I generate RSA key for ssh (both server-side and client-side): dpkg-reconfigure openssh-server ssh-keygen the key generation is completed instantly. However, when I generate RSA key for gpg, ...
4
votes
3answers
495 views

SSH Public Key Authentication vs Username/password for API Access

I have a linux device that will be making periodic call to an API server, say everytime the system boots up. Everytime then it should authenticate itself and then do its thing. I can either store the ...
0
votes
2answers
116 views

Is there a risk in opening port 22 for ssh access with a network? [duplicate]

Background We have our own datacenter which houses platform specific environments and each environment is isolated. Eeach environment is also has 3 tiers (Web Servers, Application Servers & ...
3
votes
1answer
84 views

How secure is Visual host key, and how is SHA2 converted into that representation?

SHA2 has 256 bits of possibilities. Visual host key seems to have the following upper and lowercase = 26*2 numbers and symbols = 20 Additional symbols = 22 Total 94 characters represented in ...
4
votes
3answers
681 views

Is it always better to put authorized_keys in one's own .ssh directory rather than in root's .ssh directory? [duplicate]

I connect via ssh to multiple Linux servers during the day from my Mac's Terminal window. On my Mac I have the public and private keys in my .ssh directory. On the Linux servers I always use "sudo ...