952d18a214
A base system OpenSSH update in 2016 or so removed a number of ciphers from the default lists offered by the server/client, due to known weaknesses. This caused POLA issues for some users and prompted PR207679; the ciphers were restored to the default lists in r296634. When upstream removed these ciphers from the default server list, they moved them to the client-only default list. They were subsequently removed from the client default, in OpenSSH 7.9p1. The change has persisted long enough. Remove these extra ciphers from both the server and client default lists, in advance of FreeBSD 13. Reviewed by: markm, rgrimes Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D25833
180 lines
5.7 KiB
Plaintext
180 lines
5.7 KiB
Plaintext
FreeBSD maintainer's guide to OpenSSH-portable
|
||
==============================================
|
||
|
||
00) Make sure your mail spool has plenty of free space. It'll fill up
|
||
pretty fast once you're done with this checklist.
|
||
|
||
01) Download the latest OpenSSH-portable tarball and signature from
|
||
OpenBSD (https://ftp.openbsd.org/pub/OpenBSD/OpenSSH/portable/).
|
||
|
||
02) Verify the signature:
|
||
|
||
$ gpg --verify openssh-X.YpZ.tar.gz.asc
|
||
|
||
03) Unpack the tarball in a suitable directory:
|
||
|
||
$ tar xf openssh-X.YpZ.tar.gz
|
||
|
||
04) Copy to the vendor directory:
|
||
|
||
$ svn co svn+ssh://repo.freebsd.org/base/vendor-crypto/openssh/dist
|
||
$ rsync --archive --delete openssh-X.YpZ/ dist/
|
||
|
||
05) Take care of added / deleted files:
|
||
|
||
$ svn rm $(svn stat dist | awk '$1 == "!" { print $2 }')
|
||
$ svn add --no-auto-props $(svn stat dist | awk '$1 == "?" { print $2 }')
|
||
|
||
06) Commit:
|
||
|
||
$ svn commit -m "Vendor import of OpenSSH X.YpZ." dist
|
||
|
||
07) Tag:
|
||
|
||
$ svn copy -m "Tag OpenSSH X.YpZ." \
|
||
svn+ssh://repo.freebsd.org/base/vendor-crypto/openssh/dist \
|
||
svn+ssh://repo.freebsd.org/base/vendor-crypto/openssh/X.YpZ
|
||
|
||
08) Check out head and run the pre-merge script, which strips our RCS
|
||
tags from files that have them:
|
||
|
||
$ svn co svn+ssh://repo.freebsd.org/base/head
|
||
$ cd head/crypto/openssh
|
||
$ sh freebsd-pre-merge.sh
|
||
|
||
09) Merge from the vendor branch:
|
||
|
||
$ svn merge -cNNNNNN \^/vendor-crypto/openssh/dist .
|
||
|
||
A number of files have been deleted from FreeBSD's copy of ssh,
|
||
including rendered man pages (which have a .0 extension). When
|
||
svn prompts for these deleted files during the merge, choose 'r'
|
||
(leaving them deleted).
|
||
|
||
0A) Resolve conflicts. Remember to bump the version addendum in
|
||
version.h, and update the default value in ssh{,d}_config and
|
||
ssh{,d}_config.5.
|
||
|
||
0B) Diff against the vendor branch:
|
||
|
||
$ svn diff --no-diff-deleted --no-diff-added \
|
||
--ignore-properties \^/vendor-crypto/openssh/X.YpZ .
|
||
|
||
Files that have modifications relative to the vendor code, and
|
||
only those files, must have the svn:keywords property set to
|
||
FreeBSD=%H and be listed in the 'keywords' file created by the
|
||
pre-merge script.
|
||
|
||
0C) Run the post-merge script, which re-adds RCS tags to files that
|
||
need them:
|
||
|
||
$ sh freebsd-post-merge.sh
|
||
|
||
0D) Run the configure script:
|
||
|
||
$ sh freebsd-configure.sh
|
||
|
||
0E) Review changes to config.h very carefully.
|
||
|
||
Note that libwrap should not be defined in config.h; as of
|
||
r311585 it is conditional on MK_TCP_WRAPPERS.
|
||
|
||
0F) If source files have been added or removed, update the appropriate
|
||
makefiles to reflect changes in the vendor's Makefile.in.
|
||
|
||
10) Update ssh_namespace.h:
|
||
|
||
$ sh freebsd-namespace.sh
|
||
|
||
11) Build and install world, reboot, test. Pay particular attention
|
||
to pam_ssh(8), which gropes inside libssh and will break if
|
||
something significant changes or if ssh_namespace.h is out of
|
||
whack.
|
||
|
||
12) Commit, and hunker down for the inevitable storm of complaints.
|
||
|
||
|
||
|
||
An overview of FreeBSD changes to OpenSSH-portable
|
||
==================================================
|
||
|
||
0) VersionAddendum
|
||
|
||
The SSH protocol allows for a human-readable version string of up
|
||
to 40 characters to be appended to the protocol version string.
|
||
FreeBSD takes advantage of this to include a date indicating the
|
||
"patch level", so people can easily determine whether their system
|
||
is vulnerable when an OpenSSH advisory goes out. Some people,
|
||
however, dislike advertising their patch level in the protocol
|
||
handshake, so we've added a VersionAddendum configuration variable
|
||
to allow them to change or disable it. Upstream added support for
|
||
VersionAddendum on the server side, but we also support it on the
|
||
client side.
|
||
|
||
1) Modified server-side defaults
|
||
|
||
We've modified some configuration defaults in sshd:
|
||
|
||
- UsePAM defaults to "yes".
|
||
- PermitRootLogin defaults to "no".
|
||
- X11Forwarding defaults to "yes".
|
||
- PasswordAuthentication defaults to "no".
|
||
- VersionAddendum defaults to "FreeBSD-YYYYMMDD".
|
||
- PrivilegeSeparation defaults to "sandbox".
|
||
- UseDNS defaults to "yes".
|
||
|
||
2) Modified client-side defaults
|
||
|
||
We've modified some configuration defaults in ssh:
|
||
|
||
- CheckHostIP defaults to "no".
|
||
- VerifyHostKeyDNS defaults to "yes" if built with LDNS.
|
||
- VersionAddendum defaults to "FreeBSD-YYYYMMDD".
|
||
|
||
3) Canonic host names
|
||
|
||
We've added code to ssh.c to canonicize the target host name after
|
||
reading options but before trying to connect. This eliminates the
|
||
usual problem with duplicate known_hosts entries.
|
||
|
||
4) setusercontext() environment
|
||
|
||
Our setusercontext(3) can set environment variables, which we must
|
||
take care to transfer to the child's environment.
|
||
|
||
5) TCP wrappers
|
||
|
||
Support for TCP wrappers was removed in upstream 6.7p1. We've
|
||
added it back by porting the 6.6p1 code forward.
|
||
|
||
TCP wrappers support in sshd will be disabled in HEAD and will
|
||
be removed from FreeBSD in the future.
|
||
|
||
6) Agent client reference counting
|
||
|
||
We've added code to ssh-agent.c to implement client reference
|
||
counting; the agent will automatically exit when the last client
|
||
disconnects.
|
||
|
||
7) Class-based login restrictions
|
||
|
||
We've added code to auth2.c to enforce the host.allow, host.deny,
|
||
times.allow and times.deny login class capabilities.
|
||
|
||
8) HPN
|
||
|
||
We no longer have the HPN patches (adaptive buffer size for
|
||
increased throughput on high-BxD links), but we recognize and
|
||
ignore HPN-related configuration options to avoid breaking existing
|
||
configurations.
|
||
|
||
|
||
|
||
This port was brought to you by (in no particular order) DARPA, NAI
|
||
Labs, ThinkSec, Nescafé, the Aberlour Glenlivet Distillery Co.,
|
||
Suzanne Vega, and a Sanford's #69 Deluxe Marker.
|
||
|
||
-- des@FreeBSD.org
|
||
|
||
$FreeBSD$
|