4 A C compiler. Any C89 or better compiler should work. Where supported,
5 configure will attempt to enable the compiler's run-time integrity checking
6 options. Some notes about specific compilers:
7 - clang: -ftrapv and -sanitize=integer require the compiler-rt runtime
8 (CC=clang LDFLAGS=--rtlib=compiler-rt ./configure)
10 You will need working installations of Zlib and libcrypto (LibreSSL /
13 Zlib 1.1.4 or 1.2.1.2 or greater (earlier 1.2.x versions have problems):
14 http://www.gzip.org/zlib/
16 libcrypto (LibreSSL or OpenSSL >= 0.9.8f < 1.1.0)
17 LibreSSL http://www.libressl.org/ ; or
18 OpenSSL http://www.openssl.org/
20 LibreSSL/OpenSSL should be compiled as a position-independent library
21 (i.e. with -fPIC) otherwise OpenSSH will not be able to link with it.
22 If you must use a non-position-independent libcrypto, then you may need
23 to configure OpenSSH --without-pie. Note that because of API changes,
24 OpenSSL 1.1.x is not currently supported.
26 The remaining items are optional.
28 NB. If you operating system supports /dev/random, you should configure
29 libcrypto (LibreSSL/OpenSSL) to use it. OpenSSH relies on libcrypto's
30 direct support of /dev/random, or failing that, either prngd or egd
34 If your system lacks kernel-based random collection, the use of Lutz
35 Jaenicke's PRNGd is recommended.
37 http://prngd.sourceforge.net/
41 If the kernel lacks /dev/random the Entropy Gathering Daemon (EGD) is
42 supported only if libcrypto supports it.
44 http://egd.sourceforge.net/
48 OpenSSH can utilise Pluggable Authentication Modules (PAM) if your
49 system supports it. PAM is standard most Linux distributions, Solaris,
50 HP-UX 11, AIX >= 5.2, FreeBSD and NetBSD.
52 Information about the various PAM implementations are available:
54 Solaris PAM: http://www.sun.com/software/solaris/pam/
55 Linux PAM: http://www.kernel.org/pub/linux/libs/pam/
56 OpenPAM: http://www.openpam.org/
58 If you wish to build the GNOME passphrase requester, you will need the GNOME
59 libraries and headers.
64 Alternatively, Jim Knoble <jmknoble@pobox.com> has written an excellent X11
65 passphrase requester. This is maintained separately at:
67 http://www.jmknoble.net/software/x11-ssh-askpass/
71 If you wish to use --with-skey then you will need the library below
72 installed. No other S/Key library is currently known to be supported.
74 http://www.sparc.spb.su/solaris/skey/
78 sftp supports command-line editing via NetBSD's libedit. If your platform
79 has it available natively you can use that, alternatively you might try
80 these multi-platform ports:
82 http://www.thrysoee.dk/editline/
83 http://sourceforge.net/projects/libedit/
87 LDNS is a DNS BSD-licensed resolver library which supports DNSSEC.
89 http://nlnetlabs.nl/projects/ldns/
93 If you modify configure.ac or configure doesn't exist (eg if you checked
94 the code out of CVS yourself) then you will need autoconf-2.69 to rebuild
95 the automatically generated files by running "autoreconf". Earlier
96 versions may also work but this is not guaranteed.
98 http://www.gnu.org/software/autoconf/
100 Basic Security Module (BSM):
102 Native BSM support is know to exist in Solaris from at least 2.5.1,
103 FreeBSD 6.1 and OS X. Alternatively, you may use the OpenBSM
104 implementation (http://www.openbsm.org).
107 2. Building / Installation
108 --------------------------
110 To install OpenSSH with default options:
116 This will install the OpenSSH binaries in /usr/local/bin, configuration files
117 in /usr/local/etc, the server in /usr/local/sbin, etc. To specify a different
118 installation prefix, use the --prefix option to configure:
120 ./configure --prefix=/opt
124 Will install OpenSSH in /opt/{bin,etc,lib,sbin}. You can also override
125 specific paths, for example:
127 ./configure --prefix=/opt --sysconfdir=/etc/ssh
131 This will install the binaries in /opt/{bin,lib,sbin}, but will place the
132 configuration files in /etc/ssh.
134 If you are using Privilege Separation (which is enabled by default)
135 then you will also need to create the user, group and directory used by
136 sshd for privilege separation. See README.privsep for details.
138 If you are using PAM, you may need to manually install a PAM control
139 file as "/etc/pam.d/sshd" (or wherever your system prefers to keep
140 them). Note that the service name used to start PAM is __progname,
141 which is the basename of the path of your sshd (e.g., the service name
142 for /usr/sbin/osshd will be osshd). If you have renamed your sshd
143 executable, your PAM configuration may need to be modified.
145 A generic PAM configuration is included as "contrib/sshd.pam.generic",
146 you may need to edit it before using it on your system. If you are
147 using a recent version of Red Hat Linux, the config file in
148 contrib/redhat/sshd.pam should be more useful. Failure to install a
149 valid PAM file may result in an inability to use password
150 authentication. On HP-UX 11 and Solaris, the standard /etc/pam.conf
151 configuration will work with sshd (sshd will match the other service
154 There are a few other options to the configure script:
156 --with-audit=[module] enable additional auditing via the specified module.
157 Currently, drivers for "debug" (additional info via syslog) and "bsm"
158 (Sun's Basic Security Module) are supported.
160 --with-pam enables PAM support. If PAM support is compiled in, it must
161 also be enabled in sshd_config (refer to the UsePAM directive).
163 --with-prngd-socket=/some/file allows you to enable EGD or PRNGD
164 support and to specify a PRNGd socket. Use this if your Unix lacks
165 /dev/random and you don't want to use OpenSSH's builtin entropy
168 --with-prngd-port=portnum allows you to enable EGD or PRNGD support
169 and to specify a EGD localhost TCP port. Use this if your Unix lacks
170 /dev/random and you don't want to use OpenSSH's builtin entropy
173 --with-lastlog=FILE will specify the location of the lastlog file.
174 ./configure searches a few locations for lastlog, but may not find
175 it if lastlog is installed in a different place.
177 --without-lastlog will disable lastlog support entirely.
179 --with-osfsia, --without-osfsia will enable or disable OSF1's Security
180 Integration Architecture. The default for OSF1 machines is enable.
182 --with-skey=PATH will enable S/Key one time password support. You will
183 need the S/Key libraries and header files installed for this to work.
185 --with-md5-passwords will enable the use of MD5 passwords. Enable this
186 if your operating system uses MD5 passwords and the system crypt() does
187 not support them directly (see the crypt(3/3c) man page). If enabled, the
188 resulting binary will support both MD5 and traditional crypt passwords.
190 --with-utmpx enables utmpx support. utmpx support is automatic for
193 --without-shadow disables shadow password support.
195 --with-ipaddr-display forces the use of a numeric IP address in the
196 $DISPLAY environment variable. Some broken systems need this.
198 --with-default-path=PATH allows you to specify a default $PATH for sessions
199 started by sshd. This replaces the standard path entirely.
201 --with-pid-dir=PATH specifies the directory in which the sshd.pid file is
204 --with-xauth=PATH specifies the location of the xauth binary
206 --with-ssl-dir=DIR allows you to specify where your Libre/OpenSSL
210 --with-ssl-engine enables Libre/OpenSSL's (hardware) ENGINE support
212 --with-4in6 Check for IPv4 in IPv6 mapped addresses and convert them to
213 real (AF_INET) IPv4 addresses. Works around some quirks on Linux.
215 If you need to pass special options to the compiler or linker, you
216 can specify these as environment variables before running ./configure.
219 CFLAGS="-O -m486" LDFLAGS="-s" LIBS="-lrubbish" LD="/usr/foo/ld" ./configure
224 The runtime configuration files are installed by in ${prefix}/etc or
225 whatever you specified as your --sysconfdir (/usr/local/etc by default).
227 The default configuration should be instantly usable, though you should
228 review it to ensure that it matches your security requirements.
230 To generate a host key, run "make host-key". Alternately you can do so
231 manually using the following commands:
233 ssh-keygen -t [type] -f /etc/ssh/ssh_host_key -N ""
235 for each of the types you wish to generate (rsa, dsa or ecdsa) or
239 to generate keys for all supported types.
241 Replacing /etc/ssh with the correct path to the configuration directory.
242 (${prefix}/etc or whatever you specified with --sysconfdir during
245 If you have configured OpenSSH with EGD support, ensure that EGD is
246 running and has collected some Entropy.
248 For more information on configuration, please refer to the manual pages
249 for sshd, ssh and ssh-agent.
251 4. (Optional) Send survey
252 -------------------------
255 [check the contents of the file "survey" to ensure there's no information
256 that you consider sensitive]
259 This will send configuration information for the currently configured
260 host to a survey address. This will help determine which configurations
261 are actually in use, and what valid combinations of configure options
262 exist. The raw data is available only to the OpenSSH developers, however
263 summary data may be published.
268 If you experience problems compiling, installing or running OpenSSH.
269 Please refer to the "reporting bugs" section of the webpage at
270 https://www.openssh.com/