Put ssh back into the repository
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+Privilege separation, or privsep, is method in OpenSSH by which
+operations that require root privilege are performed by a separate
+privileged monitor process. Its purpose is to prevent privilege
+escalation by containing corruption to an unprivileged process.
+More information is available at:
+ http://www.citi.umich.edu/u/provos/ssh/privsep.html
+
+Privilege separation is now enabled by default; see the
+UsePrivilegeSeparation option in sshd_config(5).
+
+On systems which lack mmap or anonymous (MAP_ANON) memory mapping,
+compression must be disabled in order for privilege separation to
+function.
+
+When privsep is enabled, during the pre-authentication phase sshd will
+chroot(2) to "/var/empty" and change its privileges to the "sshd" user
+and its primary group. sshd is a pseudo-account that should not be
+used by other daemons, and must be locked and should contain a
+"nologin" or invalid shell.
+
+You should do something like the following to prepare the privsep
+preauth environment:
+
+ # mkdir /var/empty
+ # chown root:sys /var/empty
+ # chmod 755 /var/empty
+ # groupadd sshd
+ # useradd -g sshd -c 'sshd privsep' -d /var/empty -s /bin/false sshd
+
+/var/empty should not contain any files.
+
+configure supports the following options to change the default
+privsep user and chroot directory:
+
+ --with-privsep-path=xxx Path for privilege separation chroot
+ --with-privsep-user=user Specify non-privileged user for privilege separation
+
+Privsep requires operating system support for file descriptor passing.
+Compression will be disabled on systems without a working mmap MAP_ANON.
+
+PAM-enabled OpenSSH is known to function with privsep on AIX, FreeBSD,
+HP-UX (including Trusted Mode), Linux, NetBSD and Solaris.
+
+On Cygwin, Tru64 Unix, OpenServer, and Unicos only the pre-authentication
+part of privsep is supported. Post-authentication privsep is disabled
+automatically (so you won't see the additional process mentioned below).
+
+Note that for a normal interactive login with a shell, enabling privsep
+will require 1 additional process per login session.
+
+Given the following process listing (from HP-UX):
+
+ UID PID PPID C STIME TTY TIME COMMAND
+ root 1005 1 0 10:45:17 ? 0:08 /opt/openssh/sbin/sshd -u0
+ root 6917 1005 0 15:19:16 ? 0:00 sshd: stevesk [priv]
+ stevesk 6919 6917 0 15:19:17 ? 0:03 sshd: stevesk@2
+ stevesk 6921 6919 0 15:19:17 pts/2 0:00 -bash
+
+process 1005 is the sshd process listening for new connections.
+process 6917 is the privileged monitor process, 6919 is the user owned
+sshd process and 6921 is the shell process.
+
+$Id: README.privsep,v 1.16 2005/06/04 23:21:41 djm Exp $