Host *.corp !bastion.corp
  ProxyJump bastion-a.corp,bastion-b.corp
  SendEnv LANG LC_*
  User corp

Host github
  CertificateFile ~/.ssh/github-cert.pub
  CertificateFile ~/.ssh/github-alt-cert.pub
  HostName github.com
  IdentitiesOnly yes
  IdentityAgent ~/.ssh/agent
  IdentityAgent SSH_AUTH_SOCK
  IdentityFile ~/.ssh/github
  User git

Match host *.corp exec "test -f ~/.corp"
  IgnoreUnknown PubkeyAcceptedAlgorithms,PubkeyAcceptedKeyTypes
  CASignatureAlgorithms ssh-ed25519,rsa-sha2-512
  Ciphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com
  HostKeyAlgorithms ssh-ed25519,rsa-sha2-512
  HostbasedAcceptedAlgorithms ssh-ed25519,rsa-sha2-512
  HostbasedKeyTypes ssh-ed25519,rsa-sha2-512
  KbdInteractiveDevices bsdauth,pam
  KexAlgorithms sntrup761x25519-sha512,mlkem768x25519-sha256
  LocalForward [localhost]:8080 [10.0.0.1]:80
  LocalForward 9000 10.0.0.2:90
  MACs hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com
  PreferredAuthentications publickey,keyboard-interactive
  PubkeyAcceptedAlgorithms ssh-ed25519,rsa-sha2-512
  PubkeyAcceptedKeyTypes ssh-ed25519,rsa-sha2-512
  SetEnv BAR="bar baz" BAZ="with \" some \\ very \\\" fun \\\\ escapes" FOO="foo"