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 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 5908) Check out head and run the pre-merge script, which strips our RCS 60 tags from files that have them: 61 62 $ cd src/freebsd/main/crypto/openssh 63 $ sh freebsd-pre-merge.sh 64 6509) Merge from the vendor branch: 66 67 $ git subtree merge -P crypto/openssh vendor/openssh 68 69 A number of files have been deleted from FreeBSD's copy of ssh, 70 including rendered man pages (which have a .0 extension). When 71 git prompts for these deleted files during the merge, choose 'd' 72 (leaving them deleted). 73 740A) Resolve conflicts. Remember to bump the version addendum in 75 version.h, and update the default value in ssh{,d}_config and 76 ssh{,d}_config.5. 77 780B) Diff against the vendor branch: 79 80 $ git diff --diff-filter=M vendor/openssh/X.YpZ HEAD:crypto/openssh 81 82 Files that have modifications relative to the vendor code, and 83 only those files, must have the svn:keywords property set to 84 FreeBSD=%H and be listed in the 'keywords' file created by the 85 pre-merge script. 86 870C) Run the post-merge script, which re-adds RCS tags to files that 88 need them: 89 90 $ sh freebsd-post-merge.sh 91 92 These tags are not used with git, but we will leave them in place as 93 long as svn-based FreeBSD 12.x is supported. 94 950D) Run the configure script: 96 97 $ sh freebsd-configure.sh 98 990E) Review changes to config.h very carefully. 100 101 Note that libwrap should not be defined in config.h; as of 102 r311585 (233932cc2a60) it is conditional on MK_TCP_WRAPPERS. 103 1040F) If source files have been added or removed, update the appropriate 105 makefiles to reflect changes in the vendor's Makefile.in. 106 10710) Update ssh_namespace.h: 108 109 $ sh freebsd-namespace.sh 110 11111) Build and install world, reboot, test. Pay particular attention 112 to pam_ssh(8), which gropes inside libssh and will break if 113 something significant changes or if ssh_namespace.h is out of 114 whack. 115 11612) Update nanobsd's copies of the ssh config files: 117 118 tools/tools/nanobsd/rescue/Files/etc/ssh/ssh_config 119 tools/tools/nanobsd/rescue/Files/etc/ssh/sshd_config 120 12113) Commit, and hunker down for the inevitable storm of complaints. 122 123 124 125 An overview of FreeBSD changes to OpenSSH-portable 126 ================================================== 127 1280) VersionAddendum 129 130 The SSH protocol allows for a human-readable version string of up 131 to 40 characters to be appended to the protocol version string. 132 FreeBSD takes advantage of this to include a date indicating the 133 "patch level", so people can easily determine whether their system 134 is vulnerable when an OpenSSH advisory goes out. Some people, 135 however, dislike advertising their patch level in the protocol 136 handshake, so we've added a VersionAddendum configuration variable 137 to allow them to change or disable it. Upstream added support for 138 VersionAddendum on the server side, but we also support it on the 139 client side. 140 1411) Modified server-side defaults 142 143 We've modified some configuration defaults in sshd: 144 145 - UsePAM defaults to "yes". 146 - PermitRootLogin defaults to "no". 147 - X11Forwarding defaults to "yes". 148 - PasswordAuthentication defaults to "no". 149 - VersionAddendum defaults to "FreeBSD-YYYYMMDD". 150 - PrivilegeSeparation defaults to "sandbox". 151 - UseDNS defaults to "yes". 152 1532) Modified client-side defaults 154 155 We've modified some configuration defaults in ssh: 156 157 - CheckHostIP defaults to "no". 158 - VerifyHostKeyDNS defaults to "yes" if built with LDNS. 159 - VersionAddendum defaults to "FreeBSD-YYYYMMDD". 160 1613) Canonic host names 162 163 We've added code to ssh.c to canonicize the target host name after 164 reading options but before trying to connect. This eliminates the 165 usual problem with duplicate known_hosts entries. 166 1674) setusercontext() environment 168 169 Our setusercontext(3) can set environment variables, which we must 170 take care to transfer to the child's environment. 171 1725) TCP wrappers 173 174 Support for TCP wrappers was removed in upstream 6.7p1. We've 175 added it back by porting the 6.6p1 code forward. 176 177 TCP wrappers support in sshd will be disabled in HEAD and will 178 be removed from FreeBSD in the future. 179 1806) Agent client reference counting 181 182 We've added code to ssh-agent.c to implement client reference 183 counting; the agent will automatically exit when the last client 184 disconnects. 185 1867) Class-based login restrictions (27ceebbc2402) 187 188 We've added code to auth.c to enforce the host.allow, host.deny, 189 times.allow and times.deny login class capabilities, based on an 190 upstream submission from 191 https://github.com/openssh/openssh-portable/pull/262. 192 1938) HPN 194 195 We no longer have the HPN patches (adaptive buffer size for 196 increased throughput on high-BxD links), but we recognize and 197 ignore HPN-related configuration options to avoid breaking existing 198 configurations. 199 200 201 202This port was brought to you by (in no particular order) DARPA, NAI 203Labs, ThinkSec, Nescafé, the Aberlour Glenlivet Distillery Co., 204Suzanne Vega, and a Sanford's #69 Deluxe Marker. 205 206 -- des@FreeBSD.org 207 208$FreeBSD$ 209