ssl_password_file

This directive appeared in version 1.7.3.

Specifies a file with passphrases for secret keys where each passphrase is specified on a separate line. Passphrases are tried in turn when loading the key.

Example:

mail {
    ssl_password_file /etc/keys/global.pass;
    ...

    server {
        server_name mail1.example.com;
        ssl_certificate_key /etc/keys/first.key;
    }

    server {
        server_name mail2.example.com;

        # named pipe can also be used instead of a file
        ssl_password_file /etc/keys/fifo;
        ssl_certificate_key /etc/keys/second.key;
    }
}