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Uploading SSH Public Keys using PuTTYGen

FAQ (Frequently Asked Questions)


Updated: July 10, 2017
July 10, 2017

How to upload a SSH public key using the public key created by the PuTTYGen

Upload your SSH key allows you to upload a public key used for logging onto the SSH server using a public key authentication method. This public key must be in the openssh format.

A set of public key and private key can be generated in the Windows environment by using the PuTTYGen. However, the public key saved in a file using the “Save public key” button in the PuTTYGen cannot then be uploaded using “Upload your SSH key”.

The following provides information on how to generate a public key using the PuTTYGen, and then uploading it.

Start the PuTTYGen from the start menu in the Windows environment.

Start the PuTTYGen

A set of public key/secret key will be generated by clicking on the “Generate” button in the PuTTYGen.

Generate a public key and private key

Process of generating a public key and private key

The section shown below framed in red is the public key in the openssh format. Copy this on to the clip board, and then upload it using “Upload your SSH key”

Public key in the openssh format

Uploading the public key

Once the above procedure has been completed, set a passphrase on the private key and save it in a file using the “Save public key” button. This secret key allows you to log in to the SSH server. Please refer to “SSH Server” in "Use of ECCS from Off-campus" page for details on how to connect to the SSH server.

Supplementary Information

The public key saved using the “Save public key” button in the PuTTYGen is in the RFC4716 format . Public keys in this format cannot be uploaded using “Upload your SSH key”.

If you convert a public key in the RFC4716 format to opens format using the following steps, the public key can be uploaded using “Upload your SSH key”. In these steps, a file name of the public key saved using “Save public key” button in the PuTTYGen will be rfc4716.pub. 

$ ssh-keygen -i -m RFC4716 -f rfc4716.pub
ssh-rsa      
AAAAB3NzaC1yc2EAAAABJQAAAQEAtg5uBSc4HkWO6PXztd2Zis7pC7M5XvLGHjVgCFUMCEg8OAkQZmaxZ6R
...
0kZ3uSq7BExtQpRbObwqLnli+XFlBbSRhGQ==

Save the above as a file and upload it using the "select file option" in “Upload your SSH key”. It is also possible to upload it by copying and pasting the above text.