ssh config examples - multiple identity files

ssh_config_notes

AddKeysToAgent ask

# Managing multiple github keys with host entries and defaults with exclusions
# Test with: 
# ssh -T git@asdf
# ssh -T git@github.com
Host github.com
  UseKeychain yes
  AddKeysToAgent yes
  IdentityFile ~/.ssh/id_rsa
  HostName github.com
  User git
  IdentitiesOnly yes
Host asdf
  UseKeychain yes
  AddKeysToAgent yes
  IdentityFile ~/.ssh/github-asdf
  HostName github.com
  User git
  IdentitiesOnly yes
# Example default with exclusion for specific host entries
Host * !asdf
  UseKeychain yes
  AddKeysToAgent yes
  IdentityFile ~/.ssh/id_rsa
# Apparently you can define multiple match strings per Host separated by spaces and ! is the exclusionary



# https://stribika.github.io/2015/01/04/secure-secure-shell.html
# This should be last as a default
HOST *
    USER my_default_username
#     KexAlgorithms curve25519-sha256@libssh.org,diffie-hellman-group-exchange-sha256
#     PasswordAuthentication no
#     ChallengeResponseAuthentication no
#     PubkeyAuthentication yes
#     HostKeyAlgorithms ssh-ed25519-cert-v01@openssh.com,ssh-rsa-cert-v01@openssh.com,ssh-ed25519,ssh-rsa
#     Ciphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr
#     MACs hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-512,hmac-sha2-256,umac-128@openssh.com
#     UseRoaming no