1 FreeBSD maintainer's guide to OpenSSH-portable 2 ============================================== 3 400) Make sure your mail spool has plenty of free space. It'll fill up 5 pretty fast once you're done with this checklist. 6 701) Download the latest OpenSSH-portable tarball and signature from 8 OpenBSD (ftp://ftp.openbsd.org/pub/OpenBSD/OpenSSH/portable/). 9 1002) Verify the signature: 11 12 $ gpg --verify openssh-X.YpZ.tar.gz.asc 13 1403) Unpack the tarball in a suitable directory: 15 16 $ tar xf openssh-X.YpZ.tar.gz 17 1804) Copy to the vendor directory: 19 20 $ svn co svn+ssh://repo.freebsd.org/base/vendor-crypto/openssh/dist 21 $ rsync --archive --delete openssh-X.YpZ/ dist/ 22 2305) Take care of added / deleted files: 24 25 $ svn rm $(svn stat dist | awk '$1 == "!" { print $2 }') 26 $ svn add --no-auto-props $(svn stat dist | awk '$1 == "?" { print $2 }') 27 2806) Commit: 29 30 $ svn commit -m "Vendor import of OpenSSH X.YpZ." dist 31 3207) Tag: 33 34 $ svn copy -m "Tag OpenSSH X.YpZ." \ 35 svn+ssh://repo.freebsd.org/base/vendor-crypto/openssh/dist \ 36 svn+ssh://repo.freebsd.org/base/vendor-crypto/openssh/X.YpZ 37 3808) Check out head and run the pre-merge script, which strips our RCS 39 tags from files that have them: 40 41 $ svn co svn+ssh://repo.freebsd.org/base/head 42 $ cd head/crypto/openssh 43 $ sh freebsd-pre-merge.sh 44 4509) Merge from the vendor branch: 46 47 $ svn merge -cNNNNNN \^/vendor-crypto/openssh/dist . 48 490A) Resolve conflicts. Remember to bump the version addendum in 50 version.h, and update the default value in ssh{,d}_config and 51 ssh{,d}_config.5. 52 530B) Diff against the vendor branch: 54 55 $ svn diff --no-diff-deleted --no-diff-added \ 56 --ignore-properties \^/vendor-crypto/openssh/X.YpZ . 57 58 Files that have modifications relative to the vendor code, and 59 only those files, must have the svn:keywords property set to 60 FreeBSD=%H and be listed in the 'keywords' file created by the 61 pre-merge script. 62 630C) Run the post-merge script, which re-adds RCS tags to files that 64 need them: 65 66 $ sh freebsd-post-merge.sh 67 680D) Run the configure script: 69 70 $ sh freebsd-configure.sh 71 720E) Review changes to config.h very carefully. 73 740F) If source files have been added or removed, update the appropriate 75 makefiles to reflect changes in the vendor's Makefile.in. 76 7710) Update ssh_namespace.h: 78 79 $ sh freebsd-namespace.sh 80 8111) Build and install world, reboot, test. Pay particular attention 82 to pam_ssh(8), which gropes inside libssh and will break if 83 something significant changes or if ssh_namespace.h is out of 84 whack. 85 8612) Commit, and hunker down for the inevitable storm of complaints. 87 88 89 90 An overview of FreeBSD changes to OpenSSH-portable 91 ================================================== 92 930) VersionAddendum 94 95 The SSH protocol allows for a human-readable version string of up 96 to 40 characters to be appended to the protocol version string. 97 FreeBSD takes advantage of this to include a date indicating the 98 "patch level", so people can easily determine whether their system 99 is vulnerable when an OpenSSH advisory goes out. Some people, 100 however, dislike advertising their patch level in the protocol 101 handshake, so we've added a VersionAddendum configuration variable 102 to allow them to change or disable it. Upstream added support for 103 VersionAddendum on the server side, but we also support it on the 104 client side. 105 1061) Modified server-side defaults 107 108 We've modified some configuration defaults in sshd: 109 110 - UsePAM defaults to "yes". 111 - PermitRootLogin defaults to "no". 112 - X11Forwarding defaults to "yes". 113 - PasswordAuthentication defaults to "no". 114 - VersionAddendum defaults to "FreeBSD-YYYYMMDD". 115 - PrivilegeSeparation defaults to "sandbox". 116 - UseDNS defaults to "yes". 117 1182) Modified client-side defaults 119 120 We've modified some configuration defaults in ssh: 121 122 - CheckHostIP defaults to "no". 123 - VerifyHostKeyDNS defaults to "yes" if built with LDNS. 124 - VersionAddendum defaults to "FreeBSD-YYYYMMDD". 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 1324) setusercontext() environment 133 134 Our setusercontext(3) can set environment variables, which we must 135 take care to transfer to the child's environment. 136 1375) TCP wrappers 138 139 Support for TCP wrappers was removed in upstream 6.7p1. We've 140 added it back by porting the 6.6p1 code forward. 141 1426) Agent client reference counting 143 144 We've added code to ssh-agent.c to implement client reference 145 counting; the agent will automatically exit when the last client 146 disconnects. 147 1487) Class-based login restrictions 149 150 We've added code to auth2.c to enforce the host.allow, host.deny, 151 times.allow and times.deny login class capabilities. 152 1538) HPN 154 155 We no longer have the HPN patches (adaptive buffer size for 156 increased throughput on high-BxD links), but we recognize and 157 ignore HPN-related configuration options to avoid breaking existing 158 configurations. 159 1609) AES-CBC 161 162 The AES-CBC ciphers were removed from the server-side proposal list 163 in 6.7p1 due to theoretical weaknesses and the availability of 164 superior ciphers (including AES-CTR and AES-GCM). We have re-added 165 them for compatibility with third-party clients. 166 167 168 169This port was brought to you by (in no particular order) DARPA, NAI 170Labs, ThinkSec, Nescafé, the Aberlour Glenlivet Distillery Co., 171Suzanne Vega, and a Sanford's #69 Deluxe Marker. 172 173 -- des@FreeBSD.org 174 175$FreeBSD$ 176