ssh-copy-id -i ~/.ssh/id_rsa.pub '-p 2234 user@machine'

Hat tip to Mike Gerwitz for getting me looking in the right direction, although the solution described on his blog does not work with the version of ssh-copy-id I have. (Edit: Looks like the same solution that I arrived at was pointed out in the comments on the above blog post.)

ssh-keygen -y -f key.pem > key.pub

-i This option will read an unencrypted private (or public) key file in SSH2-compatible format and print an OpenSSH compatible private (or public) key to stdout. ssh-keygen also reads the RFC 4716 SSH Public Key File Format. This option allows importing keys from several commercial SSH implementations.

e.g.:

ssh-keygen -i -f user.ssh2.pub > user.ossh.pub

Distilled instructions:

• Assuming you are building from source, add the following to your site.config.m4:

  APPENDDEF(`confENVDEF', `-D_FFR_TLS_1')
  

• Next, rebuild the Sendmail binary; when finished, add the following to your sendmail.mc and rebuild your sendmail.cf:

  LOCAL_CONFIG
  O CipherList=DH
  

  (Assuming, for whatever reasons, you want to limit ciphers to Diffie-Hellman varieties. Adjust as necessary.)

You can verify your CipherList values using OpenSSL:

> openssl ciphers DH
ADH-AES256-SHA:DHE-RSA-AES256-SHA:DHE-DSS-AES256-SHA:ADH-AES128-SHA:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA:ADH-DES-CBC3-SHA:ADH-DES-CBC-SHA:EXP-ADH-DES-CBC-SHA:ADH-RC4-MD5:EXP-ADH-RC4-MD5:EDH-RSA-DES-CBC3-SHA:EDH-RSA-DES-CBC-SHA:EXP-EDH-RSA-DES-CBC-SHA:EDH-DSS-DES-CBC3-SHA:EDH-DSS-DES-CBC-SHA:EXP-EDH-DSS-DES-CBC-SHA

Tested against Sendmail 8.14.1.

1. Copy your SSH public key to your authorized_keys on another host:

   ssh-copy-id [-i [identity_file]] [user@]machine
   

2. Login to a host you can’t directly reach, through an intermediary that can reach the host:

   ssh -t reachable_host ssh unreachable_host
   

   (The -t flag is necessary to allocate a pseudo-tty.)

3. Use a Wireshark running locally to inspect traffic that a remote host sees:

   ssh root@example.com tshark -w - not tcp port 22 | wireshark -k -i -
   

   or

   ssh root@example.com tcpdump -U -w - not port 22 | wireshark -k -i -
   

   (Of course, if you need to inspect SSH traffic, you’ll need to exclude the IP address of the local host running SSH from the remote tshark or tcpdump command. Also, the above assumes the use of SSH keypair authentication with the remote host – see Wireshark’s Pipes page for ideas if you need to enter a password on the command line.)

lpr -P printer-queue -o page-ranges=1-2 document.pdf

Reference: Command-Line Printing and Options

# ssh-keygen -f /etc/ssh/ssh_host_rsa_key -N '' -t rsa
# ssh-keygen -f /etc/ssh/ssh_host_dsa_key -N '' -t dsa

The Postfix equivalent is:

postqueue -f