RSA to PKCS

eantoranz · 06-18-2009, 01:03 PM

Hi!

I'm trying to set up a public RSA key on a router. Now, in the instructions, it says that I need to encode the public key to PKCS. It says I can use sshkey.exe, but i refuse to use something on windows.... even more, I expect to learn how to do it on GNU/Linux. How can I do it?

Thanks in advance

anomie · 06-20-2009, 02:52 PM

Check the rsa(1) manpages. It looks like you could probably use:

$ openssl rsa -outform DER -in key.here -out new.key.here

I have not tested that. It might require some more investigation and some tweaking.

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edit: Also check the pkcs8(1) manpages...

eantoranz · 06-30-2009, 03:01 PM

Anomie, thanks for your reply. I retook this problem. See, when i try to generate the pkcs from the private key, it works. However, when i try with the private key, it complains. See:

Code:

$ openssl rsa -outform DER -in id_rsa -out id_rsa.priv.pkcs
writing RSA key
$ openssl rsa -pubin -outform DER -in id_rsa.pub -out id_rsa.pub.pkcs
unable to load Public Key
11146:error:0906D06C:PEM routines:PEM_read_bio:no start line:pem_lib.c:647:Expecting: PUBLIC KEY

Both files (id_rsa and id_rsa.pub) where generated in a single ssh-keygen execution. Any idea what I'm missing?

eantoranz · 06-30-2009, 03:12 PM

I think I got it. I have to use the private key as input and tell it to put out the public key:

Code:

$ openssl rsa -outform DER -pubout -in id_rsa -out id_rsa.pub.pkcs
writing RSA key