How to use PEM format public key correctly in opal-server?

[hongbo-miao]

Method 1 - RFC-4253 of SSH succeed in opal-server

OPAL_AUTH_PRIVATE_KEY_PASSPHRASE="ds6l3qYYx9UsYcgshmlbsMJTXs1lVH9ndf13Xp1xNKxbqjFdxFvdkJxpm0DfjAhh"
ssh-keygen -t rsa -b 4096 -m pem -f id_rsa -N "${OPAL_AUTH_PRIVATE_KEY_PASSPHRASE}"

This will generate both id_rsa and id_rsa.pub
The public key is in RFC-4253 SSH format.

Above works in opal-server with default envs

OPAL_AUTH_PRIVATE_KEY_FORMAT=pem
OPAL_AUTH_PUBLIC_KEY_FORMAT=ssh

However, I am not sure how to validate it in Go. I have a question at https://stackoverflow.com/questions/69662259/key-is-of-invalid-type

Method 2 - PKCS#1 of PEM failed in opal-server

OPAL_AUTH_PRIVATE_KEY_PASSPHRASE="ds6l3qYYx9UsYcgshmlbsMJTXs1lVH9ndf13Xp1xNKxbqjFdxFvdkJxpm0DfjAhh"
ssh-keygen -t rsa -b 4096 -m pem -f id_rsa -N "${OPAL_AUTH_PRIVATE_KEY_PASSPHRASE}"
ssh-keygen -e -m pem -f id_rsa > id_rsa.pub -P ${OPAL_AUTH_PRIVATE_KEY_PASSPHRASE}

The public key is in PKCS#1 PEM format.
This failed in opal-server with

OPAL_AUTH_PRIVATE_KEY_FORMAT=pem
OPAL_AUTH_PUBLIC_KEY_FORMAT=pem

Method 3 - X.509/SPKI of PEM failed in opal-server

OPAL_AUTH_PRIVATE_KEY_PASSPHRASE="ds6l3qYYx9UsYcgshmlbsMJTXs1lVH9ndf13Xp1xNKxbqjFdxFvdkJxpm0DfjAhh"
ssh-keygen -t rsa -b 4096 -m pem -f id_rsa -N "${OPAL_AUTH_PRIVATE_KEY_PASSPHRASE}"
ssh-keygen -e -m pkcs8 -f id_rsa > id_rsa.pub -P ${OPAL_AUTH_PRIVATE_KEY_PASSPHRASE}

The public key is in X.509/SPKI PEM format.
This failed in opal-server with

OPAL_AUTH_PRIVATE_KEY_FORMAT=pem
OPAL_AUTH_PUBLIC_KEY_FORMAT=pem

[asafc]

Hey @hongbo-miao, let me dive deeper into python cryptography library and make sure OPAL supports all these key types.

I am making this into a feature request (became issue: #165)