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://svn.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://svn.freebsd.org/base/vendor-crypto/openssh/dist \ 36 svn+ssh://svn.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://svn.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) Build libssh: 78 79 $ cd ../../secure/lib/libssh && make obj && make depend && make 80 8111) Follow the instructions in ssh_namespace.h to get a list of new 82 symbols, and them to ssh_namespace.h. Keep it sorted! 83 8412) Build and install world, reboot, test. Pay particular attention 85 to pam_ssh(8), which gropes inside libssh and will break if 86 something significant changes or if ssh_namespace.h is out of 87 whack. 88 8913) Commit, and hunker down for the inevitable storm of complaints. 90 91 92 93 An overview of FreeBSD changes to OpenSSH-portable 94 ================================================== 95 960) VersionAddendum 97 98 The SSH protocol allows for a human-readable version string of up 99 to 40 characters to be appended to the protocol version string. 100 FreeBSD takes advantage of this to include a date indicating the 101 "patch level", so people can easily determine whether their system 102 is vulnerable when an OpenSSH advisory goes out. Some people, 103 however, dislike advertising their patch level in the protocol 104 handshake, so we've added a VersionAddendum configuration variable 105 to allow them to change or disable it. Upstream added support for 106 VersionAddendum on the server side, but we also support it on the 107 client side. 108 1091) Modified server-side defaults 110 111 We've modified some configuration defaults in sshd: 112 113 - UsePAM defaults to "yes". 114 - PermitRootLogin defaults to "no". 115 - X11Forwarding defaults to "yes". 116 - PasswordAuthentication defaults to "no". 117 - VersionAddendum defaults to "FreeBSD-YYYYMMDD". 118 - PrivilegeSeparation defaults to "sandbox". 119 - UseDNS defaults to "yes". 120 1212) Modified client-side defaults 122 123 We've modified some configuration defaults in ssh: 124 125 - CheckHostIP defaults to "no". 126 - VerifyHostKeyDNS defaults to "yes" if built with LDNS. 127 - VersionAddendum defaults to "FreeBSD-YYYYMMDD". 128 1293) Canonic host names 130 131 We've added code to ssh.c to canonicize the target host name after 132 reading options but before trying to connect. This eliminates the 133 usual problem with duplicate known_hosts entries. 134 1354) setusercontext() environment 136 137 Our setusercontext(3) can set environment variables, which we must 138 take care to transfer to the child's environment. 139 1405) TCP wrappers 141 142 Support for TCP wrappers was removed in upstream 6.7p1. We've 143 added it back by porting the 6.6p1 code forward. 144 1456) Agent client reference counting 146 147 We've added code to ssh-agent.c to implement client reference 148 counting; the agent will automatically exit when the last client 149 disconnects. 150 1517) Class-based login restrictions 152 153 We've added code to auth2.c to enforce the host.allow, host.deny, 154 times.allow and times.deny login class capabilities. 155 1568) HPN 157 158 We no longer have the HPN patches (adaptive buffer size for 159 increased throughput on high-BxD links), but we recognize and 160 ignore HPN-related configuration options to avoid breaking existing 161 configurations. 162 1639) AES-CBC 164 165 The AES-CBC ciphers were removed from the server-side proposal list 166 in 6.7p1 due to theoretical weaknesses and the availability of 167 superior ciphers (including AES-CTR and AES-GCM). We have re-added 168 them for compatibility with third-party clients. 169 170 171 172This port was brought to you by (in no particular order) DARPA, NAI 173Labs, ThinkSec, Nescafé, the Aberlour Glenlivet Distillery Co., 174Suzanne Vega, and a Sanford's #69 Deluxe Marker. 175 176 -- des@FreeBSD.org 177 178$FreeBSD$ 179