- Generate Authentication Key For Sftp File
- Sftp Key Based Authentication
- Sftp Authentication Methods
- Public Key Authentication Sftp
Home Managed File Transfer Guides and Tutorials Two-factor Authentication Using SSH Keys and Passwords for SFTP Two-factor Authentication Using SSH Keys and Passwords for SFTP. SFTP uses a combination of asymmetric (public key) cryptology and symmetric cryptology to provide strong encryption and optimal performance. Apr 06, 2012 SAP Netweaver PI based SFTP Adapters. The following sections briefly describe the steps to create SSH key pairs which can be used as an alternative for password based authentication. It also includes steps to verify key based authentication and import the keys in NWA key storage. It mainly foucses on creating PKCS12 Keys from OpenSSH Keys.
Overview
Public key authentication is a way of logging into an SSH/SFTP account using a cryptographic key rather than a password.
If you use very strong SSH/SFTP passwords, your accounts are already safe from brute force attacks. However, using public key authentication provides many benefits when working with multiple developers. For example, with SSH keys you can
- allow multiple developers to log in as the same system user without having to share a single password between them;
- revoke a single developer's access without revoking access by other developers; and
- make it easier for a single developer to log in to many accounts without needing to manage many different passwords.
How Public Key Authentication Works
Keys come in pairs of a public key and a private key. Each key pair is unique, and the two keys work together.
These two keys have a very special and beautiful mathematical property: if you have the private key, you can prove you have it without showing what it is. It's like proving you know a password without having to show someone the password.
Public key authentication works like this:
- Generate a key pair.
- Give someone (or a server) the public key.
- Later, anytime you want to authenticate, the person (or the server) asks you to prove you have the private key that corresponds to the public key.
- You prove you have the private key.
You don't have to do the math or implement the key exchange yourself. The SSH server and client programs take care of this for you.
Generate an SSH Key Pair
You should generate your key pair on your laptop, not on your server. All Mac and Linux systems include a command called ssh-keygen that will generate a new key pair.
If you're using Windows, you can generate the keys on your server. Just remember to copy your keys to your laptop and delete your private key from the server after you've generated it.
To generate an SSH key pair, run the command ssh-keygen.
It will look like this when you run it:
Go to Windows Start menu → All Programs → PuTTY → PuTTYgen. Creating a new key pair for authentication. To create a new key pair, select the type of key to generate from the bottom of the screen (using SSH-2 RSA with 2048 bit key size is good for most people; another good well-known alternative is. To generate an SSH key in Windows 10: Ensure the Windows 10 OpenSSH client is installed. Run “ssh-keygen” in Command Prompt and follow the instructions to generate your key. Ssh key generation for windows. Sep 26, 2019 Manually generating your SSH key in Windows. Modified: 26 Sep 2019 21:20 UTC. On Windows, you can create SSH keys in many ways. This document explains how to use two SSH applications, PuTTY and Git Bash. Joyent recommends RSA keys because the node-manta CLI programs work with RSA keys both locally and with the ssh agent. DSA keys will work. I am having a really hard time getting my SSH keys up and running after installing Windows 10. Normal method is create it and throw it in the user's account under.ssh. This folder does not appea.
You'll be prompted to choose the location to store the keys. The default location is good unless you already have a key. Press Enter to choose the default location.
Next, you'll be asked to choose a password. Using a password means a password will be required to use the private key. It's a good idea to use a password on your private key.
After you choose a password, your public and private keys will be generated. There will be two different files. The one named id_rsa is your private key. The one named id_rsa.pub is your public key.
You'll also be shown a fingerprint and 'visual fingerprint' of your key. You do not need to save these.
Configure an SSH/SFTP User for Your Key
Method 1: Using ssh-copy-id
Now that you have an SSH key pair, you're ready to configure your app's system user so you can SSH or SFTP in using your private key.
To copy your public key to your server, run the following command. Be sure to replace 'x.x.x.x' with your server's IP address and SYSUSER with the name of the the system user your app belongs to.
Method 2: Manual Configuration
Generate Authentication Key For Sftp File
If you don't have the ssh-copy-id command (for example, if you are using Windows), you can instead SSH in to your server and manually create the .ssh/authorized_keys file so it contains your public key.
First, run the following commands to make create the file with the correct permissions.
Next, edit the file .ssh/authorized_keys using your preferred editor. Copy and paste your id_rsa.pub file into the file.
Log In Using Your Private Key
You can now SSH or SFTP into your server using your private key. From the command line, you can use:
If you didn't create your key in the default location, you'll need to specify the location:
If you're using a Windows SSH client, such as PuTTy, look in the configuration settings to specify the path to your private key.
Granting Access to Multiple Keys
The .ssh/authorized_keys file you created above uses a very simple format: it can contain many keys as long as you put one key on each line in the file.
If you have multiple keys (for example, one on each of your laptops) or multiple developers you need to grant access to, just follow the same instructions above using ssh-copy-id or manually editing the file to paste in additional keys, one on each line.
When you're done, the .ssh/authorized_keys file will look something like this (don't copy this, use your own public keys):
Additional Information
Retrieve Your Public Key from Your Private Key
The following command will retrieve the public key from a private key:
This can be useful, for example, if your server provider generated your SSH key for you and you were only able to download the private key portion of the key pair.
Note that you cannot retrieve the private key if you only have the public key.
Correcting Permissions on the .ssh Directory
The instructions in this article will create your server's .ssh directory and .ssh/authorized_keys file with the correct permissions. However, if you've created them yourself and need to fix permissions, you can run the following commands on your server while SSH'd in as your app's system user.
Disabling Password Authentication
NOTE: When changing anything about the way SSH is accessed(ports, authentication methods, et cetera), it is very strongly recommended to leave an active root SSH session open until everything is working as intended. This ensures you have a way to revert changes in the event something goes wrongand logins are not working properly.
As an extra security precaution, once you have set up SSH keys, you may wish to disable password authentication entirely. This will mean no users will be able to log into SSH or SFTP without SSH keys. Anyone entering a password will receive a message like:
Sftp Key Based Authentication
Or:
Disabling password authentication is an excellent way to improve server security. Please see our guide here for the steps to accomplish this goal.
Then, test whether you're able to log in with a password by opening a new SSH or SFTP session to the server. Passwords should not be able to be used and, if everything has been done correctly, an error will be issued when someone tries to use a password. Unless this setting is changed back to allow password authentication, no users will be able to log in without an SSH key set up.
This guide contains description of setting up public key authentication for use with WinSCP. You may want to learn more about public key authentication or SSH keys instead.
- Configure Server to Accept Public Key
Advertisement
Before starting you should:
- Have WinSCP installed;
- Know how to connect to the server without public key authentication.
If you do not have a key pair yet, start with generating new key pair.
Connect to your SSH server using WinSCP with the SSH protocol, using other means of authentication than public key, e.g. typically using password authentication.
Once logged in, configure your server to accept your public key. That varies with SSH server software being used. The most common SSH server is OpenSSH.
You can use Session > Install Public Key into Server command on the main window, or Tools > Install Public Key into Server command on SSH > Authentication page page on Advanced Site Settings dialog. The functionality of the command is similar to that of OpenSSH
ssh-copy-id
command.Or you can configure the key manually:
- Navigate into a
.ssh
subdirectory of your account home directory. You may need to enable showing hidden files to see the directory. If the directory does not exists, you need to create it first. - Once there, open a file
authorized_keys
for editing. Again you may have to create this file, if this is your first key. - Switch to the PuTTYgen window, select all of the text in the Public key for pasting into OpenSSH authorized_keys file box, and copy it to the clipboard (
Ctrl+C
). Then, switch back to the editor and insert the data into the open file, making sure it ends up all on one line. Save the file. WinSCP can show you the public key too. - Ensure that your account home directory, your
.ssh
directory and fileauthorized_keys
are not group-writable or world-writable. Recommended permissions for.ssh
directory are700
. Recommended permissions forauthorized_keys
files are600
. Read more about changing permissions.
- Save a public key file from PuTTYgen, and copy that into the
.ssh2
subdirectory of your account home directory. - In the same subdirectory, edit (or create) a file called
authorization
. In this file you should put a line likeKey mykey.pub
, withmykey.pub
replaced by the name of your key file.
For other SSH server software, you should refer to the manual for that server.
When configuring session, specify path to your private key on SSH > Authentication page of Advanced Site Settings dialog.
Alternatively, load the private key into Pageant.
Cloud providers have typically their own mechanism to setup a public key authentication to virtual servers running in the cloud.
Sftp Authentication Methods
For details see guides for connecting to:
- Amazon EC2;
- Google Compute Engine;
- Microsoft Azure.
Public Key Authentication Sftp
- Using Public Keys for Authentication;
- Using PuTTYgen;
- Understanding SSH Key Pairs.