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. 8 901) 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 1202) Download the latest OpenSSH-portable tarball and signature from 13 OpenBSD (https://ftp.openbsd.org/pub/OpenBSD/OpenSSH/portable/). 14 1503) Verify the signature: 16 17 $ gpg --verify openssh-X.YpZ.tar.gz.asc 18 1904) Unpack the tarball in a suitable directory: 20 21 $ tar xf openssh-X.YpZ.tar.gz 22 2305) 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 3006) Take care of added / deleted files: 31 32 $ git add -A 33 3407) Commit: 35 36 $ git commit -m "Vendor import of OpenSSH X.YpZ" 37 3808) Tag: 39 40 $ git tag -a -m "Tag OpenSSH X.YpZ" vendor/openssh/X.YpZ 41 42 At this point the vendor branch can be pushed to the FreeBSD repo via: 43 44 $ git push freebsd vendor/openssh 45 $ git push freebsd vendor/openssh/X.YpZ 46 47 Note the second "git push" command is used to push the tag, which is 48 not pushed by default. 49 50 It is also possible to push the branch and tag together, but use 51 --dry-run first to ensure that no undesired tags will be pushed: 52 53 $ git push --dry-run --follow-tags freebsd vendor/openssh 54 $ git push --follow-tags freebsd vendor/openssh 55 56 The update and tag could instead be pushed later, along with the merge 57 to main, but pushing now allows others to collaborate. 58 5909) Merge from the vendor branch: 60 61 $ git subtree merge -P crypto/openssh vendor/openssh 62 63 A number of files have been deleted from FreeBSD's copy of ssh, 64 including rendered man pages (which have a .0 extension). When 65 git prompts for these deleted files during the merge, choose 'd' 66 (leaving them deleted). 67 6810) Resolve conflicts. Remember to bump the version addendum in 69 version.h, and update the default value in sshd_config and 70 sshd_config.5. 71 7211) Diff against the vendor branch: 73 74 $ git diff --diff-filter=M vendor/openssh/X.YpZ HEAD:crypto/openssh 75 76 Review the diff for any unexpected changes. 77 7812) Run the configure script: 79 80 $ sh freebsd-configure.sh 81 8213) 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 8714) If source files have been added or removed, update the appropriate 88 makefiles to reflect changes in the vendor's Makefile.in. 89 9015) Update ssh_namespace.h: 91 92 $ sh freebsd-namespace.sh 93 9416) 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 9917) Check for references to obsolete configuration options 100 (e.g., ChallengeResponseAuthentication in sshd_config) which 101 may exist in release/ scripts. 102 10318) Commit, and hunker down for the inevitable storm of complaints. 104 105 106 107 An overview of FreeBSD changes to OpenSSH-portable 108 ================================================== 109 1101) Modified server-side defaults 111 112 We've modified some configuration defaults in sshd: 113 114 - UsePAM defaults to "yes". 115 - PermitRootLogin defaults to "no". 116 - PasswordAuthentication defaults to "no". 117 - VersionAddendum defaults to "FreeBSD-YYYYMMDD". 118 - UseDNS defaults to "yes". 119 1202) Modified client-side defaults 121 122 We've modified some configuration defaults in ssh: 123 124 - CheckHostIP defaults to "no". 125 1263) Canonic host names 127 128 We've added code to ssh.c to canonicize the target host name after 129 reading options but before trying to connect. This eliminates the 130 usual problem with duplicate known_hosts entries. 131 132 We added this support in 2002 (r99054 / bf2e2524a2ce). In 2014 133 upstream introduced CanonicalDomains and related options to serve a 134 similar purpose but they require environment-specific configuration. 135 1364) setusercontext() environment 137 138 Our setusercontext(3) can set environment variables, which we must 139 take care to transfer to the child's environment. 140 1415) TCP wrappers 142 143 Support for TCP wrappers was removed in upstream 6.7p1. We've 144 added it back by porting the 6.6p1 code forward. 145 146 TCP wrappers support in sshd will be disabled in HEAD and will 147 be removed from FreeBSD in the future. 148 1496) Agent client reference counting 150 151 We've added code to ssh-agent.c to implement client reference 152 counting; the agent will automatically exit when the last client 153 disconnects. 154 1557) Class-based login restrictions (27ceebbc2402) 156 157 We've added code to auth.c to enforce the host.allow, host.deny, 158 times.allow and times.deny login class capabilities, based on an 159 upstream submission from 160 https://github.com/openssh/openssh-portable/pull/262. 161 1628) Blocklist integration 163 164 We include blocklist (https://github.com/zoulasc/blocklist) in FreeBSD, 165 and ssh is patched to report login failures to it. 166 1679) Paths 168 169 A number of paths are changed to match FreeBSD's configuration (e.g., 170 using /usr/local/ instead of /uxr/X11R6/). 171 17210) Retired patches 173 174 We no longer have HPN patches (adaptive buffer size for increased 175 throughput on high-BxD links) or client-side VersionAddendum, but we 176 recognize and ignore the configuration options to avoid breaking 177 existing configurations. 178 179 180 181This port was brought to you by (in no particular order) DARPA, NAI 182Labs, ThinkSec, Nescafé, the Aberlour Glenlivet Distillery Co., 183Suzanne Vega, and a Sanford's #69 Deluxe Marker. 184 185 -- des@FreeBSD.org 186