This file contains notes about OpenSSH on specific platforms. AIX Beginning with OpenSSH 3.8p1, sshd will honour an account's password expiry settings, where prior to that it did not. Because of this, it's possible for sites that have used OpenSSH's sshd exclusively to have accounts which have passwords expired longer than the inactive time (ie the "Weeks between password EXPIRATION and LOCKOUT" setting in SMIT or the maxexpired chuser attribute). Accounts in this state must have their passwords reset manually by the administrator. As a precaution, it is recommended that the administrative passwords be reset before upgrading from OpenSSH <3.8. As of OpenSSH 4.0p1, configure will attempt to detect if your version and maintenance level of AIX has a working getaddrinfo, and will use it if found. This will enable IPv6 support. If for some reason configure gets it wrong, or if you want to build binaries to work on earlier MLs than the build host then you can add "-DBROKEN_GETADDRINFO" to CFLAGS to force the previous IPv4-only behaviour. IPv6 known to work: 5.1ML7 5.2ML2 5.2ML5 IPv6 known broken: 4.3.3ML11 5.1ML4 If you wish to use dynamic libraries that aren't in the normal system locations (eg IBM's OpenSSL and zlib packages) then you will need to define the environment variable blibpath before running configure, eg blibpath=/lib:/usr/lib:/opt/freeware/lib ./configure \ --with-ssl-dir=/opt/freeware --with-zlib=/opt/freeware If sshd is built with the WITH_AIXAUTHENTICATE option (which is enabled by default) then sshd checks that users are permitted via the loginrestrictions() function, in particular that the user has the "rlogin" attribute set. This check is not done for the root account, instead the PermitRootLogin setting in sshd_config is used. If you are using the IBM compiler you probably want to use CC=xlc rather than the default of cc. Cygwin ------ To build on Cygwin, OpenSSH requires the following packages: gcc, gcc-mingw-core, mingw-runtime, binutils, make, openssl, openssl-devel, zlib, minres, minires-devel. Darwin and MacOS X ------------------ Darwin does not provide a tun(4) driver required for OpenSSH-based virtual private networks. The BSD manpage still exists, but the driver has been removed in recent releases of Darwin and MacOS X. Nevertheless, tunnel support is known to work with Darwin 8 and MacOS X 10.4 in Point-to-Point (Layer 3) and Ethernet (Layer 2) mode using a third party driver. More information is available at: http://www-user.rhrk.uni-kl.de/~nissler/tuntap/ Linux ----- Some Linux distributions (including Red Hat/Fedora/CentOS) include headers and library links in the -devel RPMs rather than the main binary RPMs. If you get an error about headers, or complaining about a missing prerequisite then you may need to install the equivalent development packages. On Redhat based distros these may be openssl-devel, zlib-devel and pam-devel, on Debian based distros these may be libssl-dev, libz-dev and libpam-dev. Solaris ------- If you enable BSM auditing on Solaris, you need to update audit_event(4) for praudit(1m) to give sensible output. The following line needs to be added to /etc/security/audit_event: 32800:AUE_openssh:OpenSSH login:lo The BSM audit event range available for third party TCB applications is 32768 - 65535. Event number 32800 has been chosen for AUE_openssh. There is no official registry of 3rd party event numbers, so if this number is already in use on your system, you may change it at build time by configure'ing --with-cflags=-DAUE_openssh=32801 then rebuilding. Platforms using PAM ------------------- As of OpenSSH 4.3p1, sshd will no longer check /etc/nologin itself when PAM is enabled. To maintain existing behaviour, pam_nologin should be added to sshd's session stack which will prevent users from starting shell sessions. Alternatively, pam_nologin can be added to either the auth or account stacks which will prevent authentication entirely, but will still return the output from pam_nologin to the client.