I have created an open-ssl private key which I would like to use to connect to my server through ssh. The openssl key was generated during certificate creation and I have to use this key on putty. The problem is that puttygen only allows openssh type keys to be converted to putty keys. How do I convert my open-ssl private key to openssh private key so I can convert it to putty key? The length of the private key is 2048 bits.

  • Why not just create a new OpenSSH key private key? – Stephen Kitt Feb 25 '16 at 17:46
  • Because I had to use openssl to create a self signed certificate which the server requires. In this process was the private key also generated. – The amateur programmer Feb 25 '16 at 17:47
  • But what does the self-signed certificate and its key have to do with SSH? – muru Feb 25 '16 at 17:50
  • Are you using certificate-based SSH authentication? (As described in the CERTIFICATES section of the ssh-keygen(1) manpage.) – Stephen Kitt Feb 25 '16 at 17:51
  • Have a look at ssh-keygen's -i and -m options, anyway. – muru Feb 25 '16 at 17:52

The RSA key formats look mighty similar to me.

bash-4.1$ openssl genrsa 4096 > whoble
bash-4.1$ ssh-keygen -t rsa -N '' -f bobble
bash-4.1$ head -c 123 whoble ; echo
bash-4.1$ head -c 123 bobble ; echo
  • They are not similar enought for puttygen to convert a key for use with putty. I have tried, but it tells me it doesn't recognize the format. Keys generated with ssh-keygen convert fine with puttygen. – The amateur programmer Feb 25 '16 at 18:12

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