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 >= 1.0.1 < 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 git 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 known 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).
108 https://www.x.org/archive/individual/util/
110 If you are making significant changes to the code you may need to rebuild
111 the dependency (.depend) file using "make depend", which requires the
112 "makedepend" tool from the X11 distribution.
114 2. Building / Installation
115 --------------------------
117 To install OpenSSH with default options:
123 This will install the OpenSSH binaries in /usr/local/bin, configuration files
124 in /usr/local/etc, the server in /usr/local/sbin, etc. To specify a different
125 installation prefix, use the --prefix option to configure:
127 ./configure --prefix=/opt
131 Will install OpenSSH in /opt/{bin,etc,lib,sbin}. You can also override
132 specific paths, for example:
134 ./configure --prefix=/opt --sysconfdir=/etc/ssh
138 This will install the binaries in /opt/{bin,lib,sbin}, but will place the
139 configuration files in /etc/ssh.
141 If you are using Privilege Separation (which is enabled by default)
142 then you will also need to create the user, group and directory used by
143 sshd for privilege separation. See README.privsep for details.
145 If you are using PAM, you may need to manually install a PAM control
146 file as "/etc/pam.d/sshd" (or wherever your system prefers to keep
147 them). Note that the service name used to start PAM is __progname,
148 which is the basename of the path of your sshd (e.g., the service name
149 for /usr/sbin/osshd will be osshd). If you have renamed your sshd
150 executable, your PAM configuration may need to be modified.
152 A generic PAM configuration is included as "contrib/sshd.pam.generic",
153 you may need to edit it before using it on your system. If you are
154 using a recent version of Red Hat Linux, the config file in
155 contrib/redhat/sshd.pam should be more useful. Failure to install a
156 valid PAM file may result in an inability to use password
157 authentication. On HP-UX 11 and Solaris, the standard /etc/pam.conf
158 configuration will work with sshd (sshd will match the other service
161 There are a few other options to the configure script:
163 --with-audit=[module] enable additional auditing via the specified module.
164 Currently, drivers for "debug" (additional info via syslog) and "bsm"
165 (Sun's Basic Security Module) are supported.
167 --with-pam enables PAM support. If PAM support is compiled in, it must
168 also be enabled in sshd_config (refer to the UsePAM directive).
170 --with-prngd-socket=/some/file allows you to enable EGD or PRNGD
171 support and to specify a PRNGd socket. Use this if your Unix lacks
174 --with-prngd-port=portnum allows you to enable EGD or PRNGD support
175 and to specify a EGD localhost TCP port. Use this if your Unix lacks
178 --with-lastlog=FILE will specify the location of the lastlog file.
179 ./configure searches a few locations for lastlog, but may not find
180 it if lastlog is installed in a different place.
182 --without-lastlog will disable lastlog support entirely.
184 --with-osfsia, --without-osfsia will enable or disable OSF1's Security
185 Integration Architecture. The default for OSF1 machines is enable.
187 --with-skey=PATH will enable S/Key one time password support. You will
188 need the S/Key libraries and header files installed for this to work.
190 --with-md5-passwords will enable the use of MD5 passwords. Enable this
191 if your operating system uses MD5 passwords and the system crypt() does
192 not support them directly (see the crypt(3/3c) man page). If enabled, the
193 resulting binary will support both MD5 and traditional crypt passwords.
195 --with-utmpx enables utmpx support. utmpx support is automatic for
198 --without-shadow disables shadow password support.
200 --with-ipaddr-display forces the use of a numeric IP address in the
201 $DISPLAY environment variable. Some broken systems need this.
203 --with-default-path=PATH allows you to specify a default $PATH for sessions
204 started by sshd. This replaces the standard path entirely.
206 --with-pid-dir=PATH specifies the directory in which the sshd.pid file is
209 --with-xauth=PATH specifies the location of the xauth binary
211 --with-ssl-dir=DIR allows you to specify where your Libre/OpenSSL
212 libraries are installed.
214 --with-ssl-engine enables Libre/OpenSSL's (hardware) ENGINE support
216 --with-4in6 Check for IPv4 in IPv6 mapped addresses and convert them to
217 real (AF_INET) IPv4 addresses. Works around some quirks on Linux.
219 If you need to pass special options to the compiler or linker, you
220 can specify these as environment variables before running ./configure.
223 CFLAGS="-O -m486" LDFLAGS="-s" LIBS="-lrubbish" LD="/usr/foo/ld" ./configure
228 The runtime configuration files are installed by in ${prefix}/etc or
229 whatever you specified as your --sysconfdir (/usr/local/etc by default).
231 The default configuration should be instantly usable, though you should
232 review it to ensure that it matches your security requirements.
234 To generate a host key, run "make host-key". Alternately you can do so
235 manually using the following commands:
237 ssh-keygen -t [type] -f /etc/ssh/ssh_host_key -N ""
239 for each of the types you wish to generate (rsa, dsa or ecdsa) or
243 to generate keys for all supported types.
245 Replacing /etc/ssh with the correct path to the configuration directory.
246 (${prefix}/etc or whatever you specified with --sysconfdir during
249 If you have configured OpenSSH with EGD support, ensure that EGD is
250 running and has collected some Entropy.
252 For more information on configuration, please refer to the manual pages
253 for sshd, ssh and ssh-agent.
255 4. (Optional) Send survey
256 -------------------------
259 [check the contents of the file "survey" to ensure there's no information
260 that you consider sensitive]
263 This will send configuration information for the currently configured
264 host to a survey address. This will help determine which configurations
265 are actually in use, and what valid combinations of configure options
266 exist. The raw data is available only to the OpenSSH developers, however
267 summary data may be published.
272 If you experience problems compiling, installing or running OpenSSH.
273 Please refer to the "reporting bugs" section of the webpage at
274 https://www.openssh.com/