1 FreeBSD maintainer's guide to OpenSSH-portable 2 ============================================== 3 4 These instructions assume you have a clone of the FreeBSD git repo 5 main branch in src/freebsd/main, and will store vendor trees under 6 src/freebsd/vendor/. In addition, this assumes there is a "freebsd" 7 origin pointing to git(repo).freebsd.org/src.git. 8 900) Make sure your mail spool has plenty of free space. It'll fill up 10 pretty fast once you're done with this checklist. 11 1201) Download the latest OpenSSH-portable tarball and signature from 13 OpenBSD (https://ftp.openbsd.org/pub/OpenBSD/OpenSSH/portable/). 14 1502) Verify the signature: 16 17 $ gpg --verify openssh-X.YpZ.tar.gz.asc 18 1903) Unpack the tarball in a suitable directory: 20 21 $ tar xf openssh-X.YpZ.tar.gz 22 2304) Copy to a vendor branch: 24 25 $ cd src/freebsd/main 26 $ git worktree add ../vendor/openssh freebsd/vendor/openssh 27 $ cd ../vendor/openssh 28 $ rsync --archive --delete --exclude=.git /path/to/openssh-X.YpZ/ ./ 29 3005) Take care of added / deleted files: 31 32 $ git add -A 33 3406) Commit: 35 36 $ git commit -m "Vendor import of OpenSSH X.YpZ" 37 3807) Tag: 39 40 $ git tag -a -m "Tag OpenSSH X.YpZ" vendor/openssh/X.YpZ 41 4208) Check out head and run the pre-merge script, which strips our RCS 43 tags from files that have them: 44 45 $ cd src/freebsd/main/crypto/openssh 46 $ sh freebsd-pre-merge.sh 47 4809) Merge from the vendor branch: 49 50 $ git subtree merge -P crypto/openssh vendor/openssh 51 52 A number of files have been deleted from FreeBSD's copy of ssh, 53 including rendered man pages (which have a .0 extension). When 54 git prompts for these deleted files during the merge, choose 'd' 55 (leaving them deleted). 56 570A) Resolve conflicts. Remember to bump the version addendum in 58 version.h, and update the default value in ssh{,d}_config and 59 ssh{,d}_config.5. 60 610B) Diff against the vendor branch: 62 63 $ git diff --diff-filter=M vendor/openssh/X.YpZ HEAD:crypto/openssh 64 65 Files that have modifications relative to the vendor code, and 66 only those files, must have the svn:keywords property set to 67 FreeBSD=%H and be listed in the 'keywords' file created by the 68 pre-merge script. 69 700C) Run the post-merge script, which re-adds RCS tags to files that 71 need them: 72 73 $ sh freebsd-post-merge.sh 74 75 These tags are not used with git, but we will leave them in place as 76 long as svn-based FreeBSD 11.x and 12.x are supported. 77 780D) Run the configure script: 79 80 $ sh freebsd-configure.sh 81 820E) Review changes to config.h very carefully. 83 84 Note that libwrap should not be defined in config.h; as of 85 r311585 (233932cc2a60) it is conditional on MK_TCP_WRAPPERS. 86 870F) If source files have been added or removed, update the appropriate 88 makefiles to reflect changes in the vendor's Makefile.in. 89 9010) Update ssh_namespace.h: 91 92 $ sh freebsd-namespace.sh 93 9411) Build and install world, reboot, test. Pay particular attention 95 to pam_ssh(8), which gropes inside libssh and will break if 96 something significant changes or if ssh_namespace.h is out of 97 whack. 98 9912) Commit, and hunker down for the inevitable storm of complaints. 100 101 102 103 An overview of FreeBSD changes to OpenSSH-portable 104 ================================================== 105 1060) VersionAddendum 107 108 The SSH protocol allows for a human-readable version string of up 109 to 40 characters to be appended to the protocol version string. 110 FreeBSD takes advantage of this to include a date indicating the 111 "patch level", so people can easily determine whether their system 112 is vulnerable when an OpenSSH advisory goes out. Some people, 113 however, dislike advertising their patch level in the protocol 114 handshake, so we've added a VersionAddendum configuration variable 115 to allow them to change or disable it. Upstream added support for 116 VersionAddendum on the server side, but we also support it on the 117 client side. 118 1191) Modified server-side defaults 120 121 We've modified some configuration defaults in sshd: 122 123 - UsePAM defaults to "yes". 124 - PermitRootLogin defaults to "no". 125 - X11Forwarding defaults to "yes". 126 - PasswordAuthentication defaults to "no". 127 - VersionAddendum defaults to "FreeBSD-YYYYMMDD". 128 - PrivilegeSeparation defaults to "sandbox". 129 - UseDNS defaults to "yes". 130 1312) Modified client-side defaults 132 133 We've modified some configuration defaults in ssh: 134 135 - CheckHostIP defaults to "no". 136 - VerifyHostKeyDNS defaults to "yes" if built with LDNS. 137 - VersionAddendum defaults to "FreeBSD-YYYYMMDD". 138 1393) Canonic host names 140 141 We've added code to ssh.c to canonicize the target host name after 142 reading options but before trying to connect. This eliminates the 143 usual problem with duplicate known_hosts entries. 144 1454) setusercontext() environment 146 147 Our setusercontext(3) can set environment variables, which we must 148 take care to transfer to the child's environment. 149 1505) TCP wrappers 151 152 Support for TCP wrappers was removed in upstream 6.7p1. We've 153 added it back by porting the 6.6p1 code forward. 154 155 TCP wrappers support in sshd will be disabled in HEAD and will 156 be removed from FreeBSD in the future. 157 1586) Agent client reference counting 159 160 We've added code to ssh-agent.c to implement client reference 161 counting; the agent will automatically exit when the last client 162 disconnects. 163 1647) Class-based login restrictions 165 166 We've added code to auth2.c to enforce the host.allow, host.deny, 167 times.allow and times.deny login class capabilities. 168 1698) HPN 170 171 We no longer have the HPN patches (adaptive buffer size for 172 increased throughput on high-BxD links), but we recognize and 173 ignore HPN-related configuration options to avoid breaking existing 174 configurations. 175 176 177 178This port was brought to you by (in no particular order) DARPA, NAI 179Labs, ThinkSec, Nescafé, the Aberlour Glenlivet Distillery Co., 180Suzanne Vega, and a Sanford's #69 Deluxe Marker. 181 182 -- des@FreeBSD.org 183 184$FreeBSD$ 185