SSH does not send all public keys

[jblaine]

2 public keys.

1 sent.

[@dev:~] $ ssh -V
OpenSSH_6.6.1p1, OpenSSL 1.0.1e-fips 11 Feb 2013
[@dev:~] $ cat /etc/redhat-release
CentOS Linux release 7.1.1503 (Core)
[@dev:~] $ ls -ld .ssh/id_rsa*pub
-rw-r--r--. 1 jblaine jblaine 393 Jun 19 10:34 .ssh/id_rsa.pub
-rw-r--r--. 1 jblaine jblaine 393 Aug  6 12:12 .ssh/id_rsa_another.pub
[@dev:~] $ ssh whoami.filippo.io

    +---------------------------------------------------------------------+
    |                                                                     |
    |             _o/ Hello!                                              |
    |                                                                     |
    |                                                                     |
    |  Did you know that ssh sends all your public keys to any server     |
    |  it tries to authenticate to? You can see yours echoed below.       |
    |                                                                     |
    |  We tried to use that to find your GitHub username, but we          |
    |  couldn't :( maybe you don't even have GitHub ssh keys, do you?     |
    |                                                                     |
    |  By the way, did you know that GitHub publishes all users'          |
    |  ssh public keys and Ben (benjojo.co.uk) grabbed them all?          |
    |                                                                     |
    |  That's pretty handy at times :) But not this time :(               |
    |                                                                     |
    |                                                                     |
    |  P.S. This whole thingy is Open Source! (And written in Go!)        |
    |  https://github.com/FiloSottile/whosthere                           |
    |                                                                     |
    |  -- @FiloSottile (https://twitter.com/FiloSottile)                  |
    |                                                                     |
    +---------------------------------------------------------------------+

ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDQwpvEpjvC+wCs41YLSxxr4Fre9Gtk4aWhoVkGWN10CQSTV3RVfDzmDsusTul0XrcetmlCQBEwfImxly1cFp/pcjTT0lAlmwuY6a8vxqCZ1D83IT8suYQIONu7dzV5PrVK1e0h02v0hGxrgGgpG1eXmD3LgCUkQHNzyQip60DmkjW6nC6lspCeJ/nghh7ioHScJfjIyMBIXI5NqumuLfnUQ7sN7fJXpsgzE5IusMikdnsOdN6qhSSjuXRAYAOyBtAv62qBQ0vYlIWFKL4iWwJG4fqXZNjBh8YpIXnLwPFD0oKmGRzRxBVPIw39qgMXJDYkjTCDmk0iclc787OIbS4N

Connection to whoami.filippo.io closed.
[@dev:~] 1 $ ls .ssh/config
ls: cannot access .ssh/config: No such file or directory
[@dev:~] 2 $

[rfc1459]

SSH sends all keys loaded in the agent, plus keys named identity (protocol 1 only) id_rsa, id_dsa (always supported), id_ecdsa and id_ed25519 (if supported).

If you're not running the agent only the default keys will be sent.

[FiloSottile]

Most users only have default and agent keys, so for them it's all keys. Advanced users that have different keys already know the configs, so we can keep it simple.