From PEM to OpenSSH for usage in ~/.ssh/authorized_keys
Say you have a private key in PEM format, and you want to use that key for SSH into another server, by adding an entry to your ~/.ssh/authorized_keys
file with the public key of such PEM file. The following command will parse your PEM file and output the required RSA format used in authorized_keys
:
ssh-keygen -y -f path/to/file.pem
This will output a ssh-rsa AAAA…
string that is safe to append to your ~/.ssh/authorized_keys
. The ssh-keygen
uses the -f
flag to specify the input file name, and the -y
flag to read a private file and output the OpenSSH public key to standard output.