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identd(1)               FreeBSD General Commands Manual              identd(1)

NAME
       identd, in.identd - TCP/IP IDENT protocol server

SYNOPSIS
       [in.]identd [options]

DESCRIPTION
       Identd is a server which implements the TCP/IP proposed standard IDENT
       user identification protocol as specified in the RFC 1413 document.

       identd operates by looking up specific TCP/IP connections and returning
       the user name of the process owning the connection.  It can optionally
       return other information instead of a user name.

OPTIONS
       -h        Display the available command line options.

       -V        Displays the version and OS version it was compiled for, and
                 then exit.

       -d        Enables extra debugging messages.

       -C<file>  Directs identd to parse additional configuration options from
                 the file specified.

       -i        May be used when starting the daemon by inetd with the
                 "nowait" option (see below).

       -w        May be used when starting the daemon by inetd with the "wait"
                 option (see below).

       -I        May be used when the daemon is started by init (see below).

       -b        flag may be used to make the daemon run in standalone mode
                 (see below).

       -u<user>  Used to specify a user number or name to which the server
                 should switch to after binding itself to the TCP/IP port and
                 opening the kernel devices.

       -g<group> Used to specify a group number or name which the server
                 should switch to after binding itself to the TCP/IP port and
                 opening the kernel devices.

       -p<port>  Used to specify an alternative TCP port to bind to, if
                 running as a standalone daemon or started by init Can be
                 specified by name or by number. Defaults to the IDENT port
                 (113).

       -t<limit> Used to specify the request timeout limit. This is the
                 maximum number of seconds a server will allow a client
                 connection to be active before terminating it. It defaults to
                 120 seconds.

       -P<pidfile>
                 Specify the location of a file to store the process number of
                 the Identd daemon.

       -K<nthreads>
                 Control the number of threads to use for kernel lookups

       -L<facility>
                 Set the syslog facility to use instead of 'daemon'.

       -o        Directs identd to return OTHER instead of UNIX as the
                 "operating system".

       -E        Enables DES encryption of the returned data (see below for
                 more information).

       -n        Directs identd to always return user numbers instead of user
                 names (for example if you wish to keep the user names a
                 secret).

       -N        Directs identd to check for a file ".noident" in each home
                 directory for the user which the daemon is about to return
                 the user name for. It that file exists then the daemon will
                 give the error HIDDEN-USER instead of the normal USERID
                 response.

       -e        Enables certain non-standard protocol extensions. Currently
                 defined extensions include the requests VERSION to return the
                 Ident daemon version and QUIT to terminate a session (useful
                 in conjunction with the -m option).

       -m        Enables identd to use a mode of operation that will allow
                 multiple requests to be processed per session. Each request
                 is specified one per line and the responses will be returned
                 one per line. The connection will not be closed until the
                 connecting part closes it's end of the line.

INSTALLATION
       The prefered way to start identd depends on how it was built.

       If it was built with support for multithreading then it should be
       started either from init , as a standalone daemon or from inetd using
       the "wait" mode (if your inetd supports it!)

       If it was built without support for multithreading then it should be
       started from inetd using the normal "nowait" mode for "stream tcp"
       services. (The main reason being that it will be single-threaded, so it
       will only serve one client connection at a time).

       identd normally will autodetect how it was invoked so there normally is
       no need to use the four command line switches (-i, -w, -I, -b).

ENCRYPTION
       DES encryption is only available if the daemon was built with support
       for it enabled.

       An encryption key (1024 bytes long) should be stored in the key file (
       /usr/local/etc/identd.key ) and it should be generated using a
       cryptographically safe random generator in order to be really safe. It
       should not contain any NUL (0x00) characters since this is used as a
       string to generate the real binary DES key.

       This file may contain multiple 1024 byte long keys, and the server will
       use the last key stored in that file.

       The returned token will contain the local and remote IP addresses and
       TCP port numbers, the local user's uid number, a timestamp, a random
       number, and a checksum - all encrypted using DES. The encrypted binary
       information is then encoded in a BASE64 string (32 characters long) and
       enclosed in square brackets to produce a token that is transmitted to
       the remote client.

       The encrypted token can later be decrypted by the idecrypt command.
       This program will attempt to decrypt a token with all the keys stored
       in the key file until it succeeds (or have tried all the keys).

CONFIGURATION FILE
       The configuration file contains a list of option=value pairs.

       syslog:facility = FACILITY
                 Set which facility to use when sending syslog messages.

       server:user = USER
                 Set what user (and group, from the passwd database) the
                 daemon should run as after it has opened all the kernel
                 handles. (Default: nobody)

       server:group = GROUP
                 Override the group id (as set by the server:user option).

       server:port = PORT
                 Set what TCP/IP port the daemon should listen to. (Default:
                 113)

       server:backlog = LIMIT
                 Set the size of the server listen() backlog limit.

       server:pid-file = PATH
                 Set the path to the file where the server will store it's
                 process id.

       server:max-request = LIMIT
                 Max number of concurrent requests allowed. Default is 0
                 (zero) which means "no limit".

       protocol:extensions = ON/OFF
                 Enable/disable the nonstandard protocol extensions ( VERSION
                 and QUIT currently). Default: off

       protocol:multiquery = ON/OFF
                 Enable/disable the multiple queries per connection feature.
                 Default: off

       protocol:timeout = SECONDS
                 Max number of seconds since connection or last request. If
                 set to 0 (zero), no timeout will be used. Default: 120
                 seconds.

       kernel:threads = LIMIT
                 Max number of threads doing kernel lookups concurrently.
                 Default: 8

       kernel:buffers = LIMIT
                 Max number of queued kernel lookup requests. Default: 32

       kernel:attempts = LIMIT
                 Max number of times to retry a kernel lookup in case of
                 failure.  Default: 5

       result:uid-only = YES/NO
                 Disable uid->username lookups (only return uid numbers).
                 Default: no

       result:noident = ON/OFF
                 Enable/disable checking for the  ".noident" file in users
                 home directories.

       result:charset = CHARSET
                 Define the character set returned in replies. Default: "US-
                 ASCII"

       result:opsys = OPSYS
                 Define the operating system returned in replies. Default:
                 "UNIX"

       result:syslog-level = LEVEL
                 If set to anything other than "none", all request replies
                 till be sent to the syslog service with the specificed
                 severity level.  Default: none

       result:encrypt = YES/NO
                 Enable encryption of replies. Only available if Identd was
                 built with a DES encryption library.

       encrypt:key-file = PATH
                 Path to the file containing the encryption keys.

       include = PATH
                 Include (and parse) the contents of another configuration
                 file.

NOTES
       The username (or UID) returned ought to be the login name. However it
       (probably, for most architecture implementations) is the "real user ID"
       as stored with the process. Thus the UID returned may be different from
       the login name for setuid programs (or those running as root) which has
       done a setuid(3) call and their children. For example, it may (should?)
       be wrong for an incoming ftpd ; and we are probably interested in the
       running shell, not the telnetd for an incoming telnet session. (But of
       course identd returns info for outgoing connections, not incoming
       ones.)

FILES
       /usr/local/etc/identd.conf
              Contains the default configuration options for identd.

       /etc/identd.pid
              Contains (if enabled) the process number of the identd daemon.

       /usr/local/etc/identd.key
              If compiled with DES encryption enabled, the 1024 first bytes of
              this file is used to specify the secret key for encrypting
              replies.

AVAILABILITY
       The daemon is free software. You can redistribute it and/or modify it
       as you wish - as long as you don't claim that you wrote it.

       The source code for the latest version of the daemon can always be
       FTP'd from one of the following addresses:

       Main site:  ftp://ftp.lysator.liu.se/pub/ident/servers/

       Mirror:     ftp://ftp.uu.net/networking/ident/servers/

       The author can be contacted at:

       Email:      Peter Eriksson <pen@lysator.liu.se>

SEE ALSO
       idecrypt(8) , ikeygen(8) , authuser(3) , inetd.conf(5) ,

                                  8 Jan 1999                         identd(1)

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | INSTALLATION | ENCRYPTION | CONFIGURATION FILE | NOTES | FILES | AVAILABILITY | SEE ALSO

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