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 46 (It could also be pushed later on, along with the merge to main, but 47 pushing now allows others to collaborate.) 48 4908) Check out head and run the pre-merge script, which strips our RCS 50 tags from files that have them: 51 52 $ cd src/freebsd/main/crypto/openssh 53 $ sh freebsd-pre-merge.sh 54 5509) Merge from the vendor branch: 56 57 $ git subtree merge -P crypto/openssh vendor/openssh 58 59 A number of files have been deleted from FreeBSD's copy of ssh, 60 including rendered man pages (which have a .0 extension). When 61 git prompts for these deleted files during the merge, choose 'd' 62 (leaving them deleted). 63 640A) Resolve conflicts. Remember to bump the version addendum in 65 version.h, and update the default value in ssh{,d}_config and 66 ssh{,d}_config.5. 67 680B) Diff against the vendor branch: 69 70 $ git diff --diff-filter=M vendor/openssh/X.YpZ HEAD:crypto/openssh 71 72 Files that have modifications relative to the vendor code, and 73 only those files, must have the svn:keywords property set to 74 FreeBSD=%H and be listed in the 'keywords' file created by the 75 pre-merge script. 76 770C) Run the post-merge script, which re-adds RCS tags to files that 78 need them: 79 80 $ sh freebsd-post-merge.sh 81 82 These tags are not used with git, but we will leave them in place as 83 long as svn-based FreeBSD 11.x and 12.x are supported. 84 850D) Run the configure script: 86 87 $ sh freebsd-configure.sh 88 890E) Review changes to config.h very carefully. 90 91 Note that libwrap should not be defined in config.h; as of 92 r311585 (233932cc2a60) it is conditional on MK_TCP_WRAPPERS. 93 940F) If source files have been added or removed, update the appropriate 95 makefiles to reflect changes in the vendor's Makefile.in. 96 9710) Update ssh_namespace.h: 98 99 $ sh freebsd-namespace.sh 100 10111) Build and install world, reboot, test. Pay particular attention 102 to pam_ssh(8), which gropes inside libssh and will break if 103 something significant changes or if ssh_namespace.h is out of 104 whack. 105 10612) Update nanobsd's copies of the ssh config files: 107 108 tools/tools/nanobsd/rescue/Files/etc/ssh/ssh_config 109 tools/tools/nanobsd/rescue/Files/etc/ssh/sshd_config 110 11113) Commit, and hunker down for the inevitable storm of complaints. 112 113 114 115 An overview of FreeBSD changes to OpenSSH-portable 116 ================================================== 117 1180) VersionAddendum 119 120 The SSH protocol allows for a human-readable version string of up 121 to 40 characters to be appended to the protocol version string. 122 FreeBSD takes advantage of this to include a date indicating the 123 "patch level", so people can easily determine whether their system 124 is vulnerable when an OpenSSH advisory goes out. Some people, 125 however, dislike advertising their patch level in the protocol 126 handshake, so we've added a VersionAddendum configuration variable 127 to allow them to change or disable it. Upstream added support for 128 VersionAddendum on the server side, but we also support it on the 129 client side. 130 1311) Modified server-side defaults 132 133 We've modified some configuration defaults in sshd: 134 135 - UsePAM defaults to "yes". 136 - PermitRootLogin defaults to "no". 137 - X11Forwarding defaults to "yes". 138 - PasswordAuthentication defaults to "no". 139 - VersionAddendum defaults to "FreeBSD-YYYYMMDD". 140 - PrivilegeSeparation defaults to "sandbox". 141 - UseDNS defaults to "yes". 142 1432) Modified client-side defaults 144 145 We've modified some configuration defaults in ssh: 146 147 - CheckHostIP defaults to "no". 148 - VerifyHostKeyDNS defaults to "yes" if built with LDNS. 149 - VersionAddendum defaults to "FreeBSD-YYYYMMDD". 150 1513) Canonic host names 152 153 We've added code to ssh.c to canonicize the target host name after 154 reading options but before trying to connect. This eliminates the 155 usual problem with duplicate known_hosts entries. 156 1574) setusercontext() environment 158 159 Our setusercontext(3) can set environment variables, which we must 160 take care to transfer to the child's environment. 161 1625) TCP wrappers 163 164 Support for TCP wrappers was removed in upstream 6.7p1. We've 165 added it back by porting the 6.6p1 code forward. 166 167 TCP wrappers support in sshd will be disabled in HEAD and will 168 be removed from FreeBSD in the future. 169 1706) Agent client reference counting 171 172 We've added code to ssh-agent.c to implement client reference 173 counting; the agent will automatically exit when the last client 174 disconnects. 175 1767) Class-based login restrictions (27ceebbc2402) 177 178 We've added code to auth.c to enforce the host.allow, host.deny, 179 times.allow and times.deny login class capabilities, based on an 180 upstream submission from 181 https://github.com/openssh/openssh-portable/pull/262. 182 1838) HPN 184 185 We no longer have the HPN patches (adaptive buffer size for 186 increased throughput on high-BxD links), but we recognize and 187 ignore HPN-related configuration options to avoid breaking existing 188 configurations. 189 190 191 192This port was brought to you by (in no particular order) DARPA, NAI 193Labs, ThinkSec, Nescafé, the Aberlour Glenlivet Distillery Co., 194Suzanne Vega, and a Sanford's #69 Deluxe Marker. 195 196 -- des@FreeBSD.org 197 198$FreeBSD$ 199