Original source can be downloaded from OpenBSD at
ftp://ftp.openbsd.org/pub/OpenBSD/OpenSSH/portable/

A list of deleted files is in README.DELETED.

Upgrading notes:
./configure --prefix=/usr --sysconfdir=/etc/ssh --with-sandbox=rlimit \
	--with-pam --with-libedit --with-ssl-engine

Update config.h in secure/lib/libssh.
Update ssh_namespace.h

Used in:
lib/pam_module/pam_ssh/
secure/lib/libssh/
secure/libexec/sftp-server/
secure/libexec/ssh-keysign/
secure/usr.bin/scp/
secure/usr.bin/sftp/
secure/usr.bin/ssh/
secure/usr.bin/ssh-add/
secure/usr.bin/ssh-agent/
secure/usr.bin/ssh-keygen/
secure/usr.bin/ssh-keyscan/
secure/usr.sbin/sshd/