1 1. Prerequisites 2 ---------------- 3 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) 9 10 You will need working installations of Zlib and libcrypto (LibreSSL / 11 OpenSSL) 12 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/ 15 16 libcrypto (LibreSSL or OpenSSL >= 0.9.8f < 1.1.0) 17 LibreSSL http://www.libressl.org/ ; or 18 OpenSSL http://www.openssl.org/ 19 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. 25 26 The remaining items are optional. 27 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 31 32 PRNGD: 33 34 If your system lacks kernel-based random collection, the use of Lutz 35 Jaenicke's PRNGd is recommended. 36 37 http://prngd.sourceforge.net/ 38 39 EGD: 40 41 If the kernel lacks /dev/random the Entropy Gathering Daemon (EGD) is 42 supported only if libcrypto supports it. 43 44 http://egd.sourceforge.net/ 45 46 PAM: 47 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. 51 52 Information about the various PAM implementations are available: 53 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/ 57 58 If you wish to build the GNOME passphrase requester, you will need the GNOME 59 libraries and headers. 60 61 GNOME: 62 http://www.gnome.org/ 63 64 Alternatively, Jim Knoble <jmknoble (a] pobox.com> has written an excellent X11 65 passphrase requester. This is maintained separately at: 66 67 http://www.jmknoble.net/software/x11-ssh-askpass/ 68 69 S/Key Libraries: 70 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. 73 74 http://www.sparc.spb.su/solaris/skey/ 75 76 LibEdit: 77 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: 81 82 http://www.thrysoee.dk/editline/ 83 http://sourceforge.net/projects/libedit/ 84 85 LDNS: 86 87 LDNS is a DNS BSD-licensed resolver library which supports DNSSEC. 88 89 http://nlnetlabs.nl/projects/ldns/ 90 91 Autoconf: 92 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. 97 98 http://www.gnu.org/software/autoconf/ 99 100 Basic Security Module (BSM): 101 102 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). 105 106 107 2. Building / Installation 108 -------------------------- 109 110 To install OpenSSH with default options: 111 112 ./configure 113 make 114 make install 115 116 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: 119 120 ./configure --prefix=/opt 121 make 122 make install 123 124 Will install OpenSSH in /opt/{bin,etc,lib,sbin}. You can also override 125 specific paths, for example: 126 127 ./configure --prefix=/opt --sysconfdir=/etc/ssh 128 make 129 make install 130 131 This will install the binaries in /opt/{bin,lib,sbin}, but will place the 132 configuration files in /etc/ssh. 133 134 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. 137 138 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. 144 145 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 152 name). 153 154 There are a few other options to the configure script: 155 156 --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. 159 160 --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). 162 163 --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 166 collection support. 167 168 --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 171 collection support. 172 173 --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. 176 177 --without-lastlog will disable lastlog support entirely. 178 179 --with-osfsia, --without-osfsia will enable or disable OSF1's Security 180 Integration Architecture. The default for OSF1 machines is enable. 181 182 --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. 184 185 --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. 189 190 --with-utmpx enables utmpx support. utmpx support is automatic for 191 some platforms. 192 193 --without-shadow disables shadow password support. 194 195 --with-ipaddr-display forces the use of a numeric IP address in the 196 $DISPLAY environment variable. Some broken systems need this. 197 198 --with-default-path=PATH allows you to specify a default $PATH for sessions 199 started by sshd. This replaces the standard path entirely. 200 201 --with-pid-dir=PATH specifies the directory in which the sshd.pid file is 202 created. 203 204 --with-xauth=PATH specifies the location of the xauth binary 205 206 --with-ssl-dir=DIR allows you to specify where your Libre/OpenSSL 207 libraries 208 are installed. 209 210 --with-ssl-engine enables Libre/OpenSSL's (hardware) ENGINE support 211 212 --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. 214 215 If you need to pass special options to the compiler or linker, you 216 can specify these as environment variables before running ./configure. 217 For example: 218 219 CFLAGS="-O -m486" LDFLAGS="-s" LIBS="-lrubbish" LD="/usr/foo/ld" ./configure 220 221 3. Configuration 222 ---------------- 223 224 The runtime configuration files are installed by in ${prefix}/etc or 225 whatever you specified as your --sysconfdir (/usr/local/etc by default). 226 227 The default configuration should be instantly usable, though you should 228 review it to ensure that it matches your security requirements. 229 230 To generate a host key, run "make host-key". Alternately you can do so 231 manually using the following commands: 232 233 ssh-keygen -t [type] -f /etc/ssh/ssh_host_key -N "" 234 235 for each of the types you wish to generate (rsa, dsa or ecdsa) or 236 237 ssh-keygen -A 238 239 to generate keys for all supported types. 240 241 Replacing /etc/ssh with the correct path to the configuration directory. 242 (${prefix}/etc or whatever you specified with --sysconfdir during 243 configuration) 244 245 If you have configured OpenSSH with EGD support, ensure that EGD is 246 running and has collected some Entropy. 247 248 For more information on configuration, please refer to the manual pages 249 for sshd, ssh and ssh-agent. 250 251 4. (Optional) Send survey 252 ------------------------- 253 254 $ make survey 255 [check the contents of the file "survey" to ensure there's no information 256 that you consider sensitive] 257 $ make send-survey 258 259 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. 264 265 5. Problems? 266 ------------ 267 268 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/ 271
