Can I use my ssh-public-key to decrypt a file?

Question

I\'m trying to find a way to decrypt an encrypted file on a \'virgin\' EC2-instance. These EC-instances I use (Ubuntu Lucid) only hold my AWS-created public ssh-key. If can use

Answer 1

The file:

echo 'This is a sekret' >/tmp/msg.txt

Export public key (in case you don't have it/lose it):

openssl rsa -in ~/private.pem -out /tmp/public.pub -outform PEM -pubout

Encrypt file with public key (anyone can have this key):

openssl rsautl -encrypt -inkey /tmp/public.pub -pubin -in /tmp/msg.txt -out /tmp/file.enc

Decrypt the file with private key (only you should have the private key):

openssl rsautl -decrypt -inkey ~/private.pem -in /tmp/file.enc -out /tmp/decrypted.txt

The decoded message:

cat /tmp/decrypted.txt

Answer 2

You can use a public key to encrypt a file but you will need the corresponding private key to decrypt it. So, yes, you should be able to use your ssh-key to encrypt/decrypt a file, as long as you have access to both the public and private key.

Answer 3

If you just want to encrypt/decrypt using your ssh keys, ssh-vault could be useful, more info here: http://ssh-vault.com/about/