encrypt small files with ssh keys
Convert RSA public key and private key to PEM format:
$ openssl rsa -in ~/.ssh/id_rsa -outform pem >
id_rsa.pem
$ openssl rsa -in ~/.ssh/id_rsa -pubout -outform pem >
id_rsa.pub.pem
Encrypting a file with your public key:
$ openssl rsautl -encrypt -pubin -inkey id_rsa.pub.pem \
-in file.txt -out file.enc
Decrypting the file with your private key:
$ openssl rsautl -decrypt -inkey id_rsa.pem \
-in file.enc -out file.txt
Of course, this is asymmetric encryption and your file must be less than or equal in size to your key!