Usenet 1993 July/InfoMagic USENET CD-ROM July 1993.ISO/sources/unix/volume22/auth/part01

Internet Message Format | 1990-04-29 | 53.8 KB

Subject:  v22i001:  RFC 931 TCP Authentication server, Part01/02
Newsgroups: comp.sources.unix
Approved: [e-mail]
X-Checksum-Snefru: 478415bf 1082bb14 40ecd74b ad50453c

Submitted-by: Dan Bernstein <[e-mail]>
Posting-number: Volume 22, Issue 1
Archive-name: auth2.1/part01

[  For more details, see rfc931 which is included in this package. --r$ ]

This package provides two benefits. The first is a secure user-level
implementation of RFC 931, the Authentication Server; unless TCP itself
is compromised, it is impossible to forge mail or news between computers
supporting RFC 931. The second is a single, modular interface to TCP.
Programs written to work with authtcp and attachport don't even need to
be recompiled to run under a more comprehensive network security system
like Kerberos, as long the auth package is replaced.

#! /bin/sh
# This is a shell archive.  Remove anything before this line, then unpack
# it by saving it into a file and typing "sh file".  To overwrite existing
# files, type "sh file -c".  You can also feed this as standard input via
# unshar, or by typing "sh <file", e.g..  If this archive is complete, you
# will see the following message at the end:
#        "End of archive 1 (of 2)."
# Contents:  CHANGES Makefile README attachport.man authd.c authd.man
#   authtcp.man authuser.c authuser.h authuser.man dir.doc djbatoi.h
#   djberr.h
# Wrapped by [e-mail] on Mon Apr 30 15:53:39 1990
PATH=/bin:/usr/bin:/usr/ucb ; export PATH
if test -f 'CHANGES' -a "${1}" != "-c" ; then
  echo shar: Will not clobber existing file \"'CHANGES'\"
else
echo shar: Extracting \"'CHANGES'\" \(3686 characters\)
sed "s/^X//" >'CHANGES' <<'END_OF_FILE'
X4/18/90: Packaged auth 2.1 to replace previous comp.sources.unix submission.
X4/18/90: authd version 2.1.
X4/18/90: authd looks much prettier.
X4/18/90: attachport version 4.1.
X4/18/90: authd supports ! lock files.
X4/18/90: attachport forks as real uid.
X4/18/90: attachport now checks periodically for lost children.
X4/18/90: Corrected locking scheme for exceptional (i.e. impossible) cases.
X4/18/90: authtcp version 2.1.
X4/18/90: authtcp forks as real uid.
X4/18/90: attachport handles signals better.
X4/18/90: authtcp handles signals better. It's annoying that extensions
X     to the signal semantics could make secure programs insecure.
X4/18/90: attachport is now just as careful.
X4/18/90: authtcp is now ridiculously careful to switch to effective uid
X     before unlinking lock file and to real uid before exiting.
X4/18/90: Aargh, fork() uses effective uid rather than real uid for
X     MAXUPRC checks. This ``feature'' can bring down attachport and
X     authtcp if MAXUPRC is small and the machine is big.
X
X4/2/90: attachport version 4.0.
X4/2/90: authtcp version 2.0.
X4/2/90: authd version 2.0.
X4/2/90: authuser version 2.0.
X4/2/90: Final packaging and distribution for comp.sources.unix.
X
X4/2/90: Everything passes lint perfectly, though not lint -hacx.
X
X4/2/90: attachport now understands SIGTERM from killaport.
X4/2/90: All programs now use inet_ntoa() where appropriate.
X4/2/90: All programs now use isascii() where appropriate.
X4/2/90: attachport now understands everything.
X4/2/90: Integrated attachport into auth distribution. attachport CHANGES:
X        3/21/90: Somehow attachport has gotten up to 3.6.
X        1/28/90: Added -0 option to wither away when input file disappears.
X        1/28/90: Added -1 option as a computer-friendly -v.
X        1/7/90: attachport 3.5.
X        Cleaned up mostly everything.
X        attachport version 3.0, 11/1/89.
X
X4/1/90: authuser now checks for USERID from the Authentication Server,
X    though it doesn't do anything informative upon a remote ERROR.
X4/1/90: authd now uses unsigned where it should.
X4/1/90: authuser now uses unsigned where it should.
X4/1/90: authtcp now uses unsigned where it should.
X4/1/90: authd now uses ctype.h appropriately.
X
X4/1/90: authd supports new locking protocol.
X4/1/90: authtcp supports new locking protocol.
X4/1/90: Set up new locking procedure to prevent authentication race
X    condition; attachport will have to support this too.
X
X3/31/90: authtcp version 1.8.
X
X3/31/90: authtcp now talks to the remote authd.
X3/31/90: authuser version 1.5.
X3/31/90: Redid authuser interface.
X3/31/90: Added authuser library to authtcpd (now just auth) distribution.
X
X3/27/90: authtcp now supports getservbyname()---and an interesting
X     inconsistency showed up! Check sockaddr_in in netinet/in.h
X     versus servent.s_port in netdb.h. Ho hum.
X3/27/90: Touched up authtcp a bit.
X
X1/31/90: authd version 1.52.
X1/31/90: authtcp version 1.52.
X
X1/31/90: authtcp now supports TSTP.
X1/31/90: Both programs now have AUTHDIR ifdefed so it can go into Makefile.
X
XGetopt usage compatible with dumb getopt (no special numeric treatment).
X
X1/7/90: authd version 1.5.
X1/7/90: authtcp version 1.5.
X
XBoth programs now use getopt.
X
Xauthd passes lint.
X
Xauthtcp: Whoops, really should turn off TSTP, as we don't handle stopping.
X
Xauthtcp keeps socket open, to close a Trojan Horse-like security hole.
Xauthtcp doesn't turn off signals for its child.
X
Xauthtcp version 1.1, 11/1/89.
X
Xauthtcp has the verbose option it's been begging for.
Xauthtcp now understands gethostbyname().
X
Xauthd version 1.001, 11/1/89.
Xauthtcp version 1.001, 11/1/89.
X
XChanged 50 in both programs to be sizeof(AUTHDIR) + 30.
X
Xauthd version 1.0, 10/26/89.
Xauthtcp version 1.0, 10/26/89.
END_OF_FILE
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if test -f 'Makefile' -a "${1}" != "-c" ; then
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else
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sed "s/^X//" >'Makefile' <<'END_OF_FILE'
XCC=cc
XCCOPTS=-O
XNROFF=nroff
XNROFFOPTS=-man
X
X# -DAUTHDIR=\"directory\"  to override default of /usr/etc/auth
X# -DAUTHTCPPORT=port  to override default of 113
X# -DMAXHOSTNAMELEN=nn  to specify maximum host name length
X#                      (default in sys/param.h, except on Suns)
X
Xdefault: all
X
Xall: attachport authtcp authd authuser.o attachport.1 authtcp.1 authd.8 authuser.3
X
Xshar: auth.shar
X
Xattachport: attachport.o authuser.o Makefile
X    $(CC) $(CCOPTS) -o attachport attachport.o authuser.o
X
Xattachport.o: attachport.c authuser.h Makefile
X    $(CC) $(CCOPTS) -c attachport.c
X
Xauthtcp: authtcp.o authuser.o Makefile
X    $(CC) $(CCOPTS) -o authtcp authtcp.o authuser.o
X
Xauthtcp.o: authtcp.c authuser.h Makefile
X    $(CC) $(CCOPTS) -c authtcp.c
X
Xauthd: authd.c Makefile
X    $(CC) $(CCOPTS) -o authd authd.c
X
Xauthuser.o: authuser.c Makefile
X    $(CC) $(CCOPTS) -c authuser.c
X
Xattachport.1: attachport.man Makefile
X    $(NROFF) $(NROFFOPTS) < attachport.man > attachport.1
X
Xauthtcp.1: authtcp.man Makefile
X    $(NROFF) $(NROFFOPTS) < authtcp.man > authtcp.1
X
Xauthd.8: authd.man Makefile
X    $(NROFF) $(NROFFOPTS) < authd.man > authd.8
X
Xauthuser.3: authuser.man Makefile
X    $(NROFF) $(NROFFOPTS) < authuser.man > authuser.3
X
Xauth.shar: CHANGES README attachport.man authtcp.man authd.man authuser.man Makefile attachport.c authtcp.c authd.c authuser.c authuser.h djberr.h djbatoi.h dir.doc rfc931
X    shar CHANGES README attachport.man authtcp.man authd.man authuser.man Makefile attachport.c authtcp.c authd.c authuser.c authuser.h djberr.h djbatoi.h dir.doc rfc931 > auth.shar
X    chmod 400 auth.shar
END_OF_FILE
if test 1570 -ne `wc -c <'Makefile'`; then
    echo shar: \"'Makefile'\" unpacked with wrong size!
fi
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fi
if test -f 'README' -a "${1}" != "-c" ; then
  echo shar: Will not clobber existing file \"'README'\"
else
echo shar: Extracting \"'README'\" \(4153 characters\)
sed "s/^X//" >'README' <<'END_OF_FILE'
Xattachport - attach a server program to a TCP port
Xauthtcp - create a locally authenticated TCP connection to an Internet host
Xauthd - authentication server daemon
Xauthuser - remote authentication library
X
XThis package provides two benefits. The first is a secure user-level
Ximplementation of RFC 931, the Authentication Server; unless TCP itself
Xis compromised, it is impossible to forge mail or news between computers
Xsupporting RFC 931. The second is a single, modular interface to TCP.
XPrograms written to work with authtcp and attachport don't even need to
Xbe recompiled to run under a more comprehensive network security system
Xlike Kerberos, as long the auth package is replaced.
X
Xattachport version 4.1, April 18, 1990.
XCopyright (c) 1990, Daniel J. Bernstein.
XAll rights reserved.
X
Xauthtcp version 2.1, April 18, 1990.
XCopyright (c) 1990, Daniel J. Bernstein.
XAll rights reserved.
X
Xauthd version 2.1, April 18, 1990.
XCopyright (c) 1990, Daniel J. Bernstein.
XAll rights reserved.
X
Xauthuser version 2.0, April 2, 1990.
XCopyright (c) 1990, Daniel J. Bernstein
XAll rights reserved.
X
XThis distribution packaged April 18, 1990.
X
XFiles:
XCHANGES         Description of changes since first distributed version
XREADME          This document
XMakefile        Installation commands
Xattachport.c    The attachport program
Xauthtcp.c       The authtcp program
Xauthd.c         The authd program
Xauthuser.c      The authuser library
Xattachport.man  Documentation
Xauthtcp.man     Documentation
Xauthd.man       Documentation
Xauthuser.man    Documentation
Xdjberr.h        Error macros
Xdjbatoi.h       Replacement atoi()---Sun's library version can crash
Xdir.doc         Description of authentication directory contents
Xrfc931          RFC 931, Authentication Server
X
XEdit the options in Makefile and type make. attachport, authtcp, and
Xauthd will be the executable programs; authuser.o will be the linkable
Xlibrary; attachport.1, authtcp.1, authd.8, and authuser.3 will be the
Xnroff'ed documentation.
X
XYou probably want to pick up the multitee and authutil packages before
Xtrying out any of these programs.
X
XFor authentication to work, you must set up a new userid, say auth.
XUid auth should not permit logins. Its encrypted password should be
Xsomething impossible, like an asterisk. Its shell should be /bin/true.
XIts home directory should be /nonexistent. Its uid should be unique.
X
Xauthtcp and attachport should be setuid auth; check the source carefully
Xfor security holes! You also need a directory /usr/etc/auth/tcp, owner
Xauth, group irrelevant, mode 0700. (You can use a different directory/tcp
Xif you set AUTHDIR in the Makefile.)
X
Xauthd should be set up under attachport(1) or inetd(8) to receive
Xconnections on TCP port 113. It should not be setuid auth, though it
Xwill always run as auth.
X
XThe authuser library needs no particular preparation; if you want to
Xmake it available to users, put it into a library archive and copy
Xauthuser.h to /usr/include.
X
XI don't pretend to know your machine's setup so there's no make install.
X
XRead CHANGES for a list of changes. Type authtcp -C and authtcp -W
Xfor copyright and warranty information, authtcp -H for help. Similarly
Xfor attachport and authd. For authuser, print authusercopyright[] and
Xauthuserwarranty[] for copyright and warranty information, authuserhelp[]
Xfor help.
X
XRead dir.doc for a description of the authentication directory as used
Xby authtcp, attachport, and authd.
X
X  Some BSD variants (notably ULTRIX) handle multiple non-root setuid
X  processes poorly. To test the behavior of your system, try the
X  following sequence from a root csh:
X      SU% cp /usr/bin/sleep /tmp/slip
X      SU% chown nobody /tmp/slip; chmod 4755 /tmp/slip
X      SU% repeat 100 sh -ic '(/tmp/slip 10000 &) 2>&1' > /tmp/pids
X      SU% /bin/kill "`cat /tmp/pids`"
X  Here 100 is any number bigger than MAXUPRC in /usr/include/sys/param.h.
X  If the repeat fails, hangs, or crashes your system, complain at your
X  vendor: you can't reliably install programs setuid to anything except
X  root. In this case you'll have to install auth setuid root rather than
X  setuid auth as per the instructions; this is perfectly safe.
END_OF_FILE
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fi
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fi
if test -f 'attachport.man' -a "${1}" != "-c" ; then
  echo shar: Will not clobber existing file \"'attachport.man'\"
else
echo shar: Extracting \"'attachport.man'\" \(7625 characters\)
sed "s/^X//" >'attachport.man' <<'END_OF_FILE'
X.TH attachport 1
X.SH NAME
Xattachport \- attach a server program to a TCP port
X.SH SYNTAX
Xattachport
X[
X\fB\-ACHUVW\fI
X] [
X\fB\-01rRvxX\fI
X] [
X\fB\-p\fIportnum
X]
Xprogram
X[
Xarg ...
X] &
X.SH DESCRIPTION
X.I attachport
Xattaches a server to a TCP port.
XThe port may be specified by
X.I portnum,
Xor one will be assigned;
Xthe server is specified by
X.I program.
X.I attachport
Xwill pass any further arguments through to the server program.
X.PP
X.I portnum
Xcan be fully specified as a port number,
Xor given as a service name.
X.PP
XAny incoming request on the TCP port
Xinvokes a new copy of the server,
Xwhich runs with all input directed from
Xand output directed to the port.
XAll environment variables and similar process data
Xare taken directly from the original invocation of
X.I attachport;
Xhowever,
X.I attachport
Xwill attempt to dissociate itself from its controlling terminal.
X.PP
X.I attachport
Xworks with
Xthe Authentication Server,
X.I authd(8):
Xthe connecting host can verify the identity of the server.
X.PP
XOptions
X.B ACHUVW
Xprint the authorship notice,
Xcopyright notice,
Xhelp notice,
Xshort usage summary,
Xversion number,
Xand warranty information respectively.
X.PP
X.I attachport
Xhas several flags:
X.TP 12
X\fB\-p\fIportnum
XAttempt to attach the server to port
X.I portnum.
XThe port number is restricted on most machines to a number between
X0 and 65535; any larger number will be mapped down into this range.
XPorts 0 through 1023 are generally restricted to root processes.
XPorts above 50000 are a good choice for user (nonstandard) servers.
XIf you do not specify a port,
X.I attachport
Xwill assign one.
X.TP
X\fB\-v\fI
XVerbose:
X.I attachport
Xwill report success.
X.TP
X\fB\-1\fI
XWrite the port number to standard output as an integer followed by
Xa newline.
XThis is the non-user-friendly version of
X\fB\-v.
X.TP
X\fB\-0\fI
XEvery ten seconds, check that the (otherwise unused) standard input
Xfile still has links. If it doesn't,
X.I attachport
Xwill slowly wither away,
Xdying as soon as its children have exited and cleaned up.
X.I attachport
Xwill refuse further connections on the same port in the meantime.
XThis is appropriate for a shell script;
Xuse
X.I killaport(1)
Xto kill
X.I attachport
Xmanually.
X.TP
X\fB\-x\fI
XLocally authenticate each connection (default).
X.TP
X\fB\-X\fI
XDo not locally authenticate connections.
X.TP
X\fB\-r\fI
XAttempt to determine the identity of the other end of
Xeach connection
Xthrough the remote Authentication Server (default).
X.I attachport
Xwill place the identity
Xinto environment variable
XREMOTE, with the form
X.I [e-mail]
Xwhere
X.I user
Xis a string giving the user name
Xand
X.I in.et.ad.dr
Xis a numerical Internet address.
XIf the other end is not authenticated,
X.I user
Xwill be blank.
XNote that
X.I user
Xmay contain @ signs;
XREMOTE should be parsed from
Xright to left.
X.I attachport
Xalso sets environment variable
XPROTO to the string
X.I TCP.
X.TP
X\fB\-R\fI
XDo not remotely authenticate.
XThis is the default if the local port is 113 (auth):
Xtwo machines caught in an Authentication Server loop
Xwould rapidly be brought to their knees,
Xthough the loop would end after user
X.I auth
Xhit its process limit on either machine.
X.PP
XThe server could use
X.I getpeername(2)
Xto find out who it's talking to,
Xbut it's faster, simpler, and more portable
Xto use PROTO and REMOTE.
XFuture versions of
X.I attachport,
Xversions for other network interfaces,
Xand versions for completely different communications systems
Xwill all provide the same PROTO/REMOTE interface.
XOf course, if PROTO is not TCP, REMOTE will probably
Xhave a different format.
X.PP
XNote that the insertion of carriage returns after newlines
Xis normally done automatically by the terminal driver.
XYou must be careful to output carriage returns before newlines
Xfor your program to talk correctly with a low-level communications server.
X.PP
XYou should make sure to run
X.I attachport
Xin the background.
XAlso, you should make sure that its diagnostic output goes
Xeither into a log file or into /dev/null.
X.SH DIAGNOSTICS
X.TP 1.5i
X\fIwarning: can't find my own Internet number?!\fB
XYour host is not listed in your hosts table?!
X.TP
X.I cannot setreuid
XThis should never happen.
X.TP
X.I cannot create socket
XSomething went wrong in creating the communications socket.
X.TP
X.I cannot bind: Address already in use
XSome other process is attached to that port.
X(Note that even if that process goes away,
Xit may be a few minutes before the port is free again.)
X.TP
X.I cannot bind: some other problem
XYou can't bind the communications socket to the port for some
Xother reason. Do you have permission for ports 0 through 1023?
X.TP
X.I cannot listen
XSomething went wrong in setting up the socket to listen for
Xincoming calls.
X.TP
X.I warning: cannot open /dev/tty
X.I attachport
Xwill not be able to dissociate itself from your terminal.
XYou should get this warning if you invoke
X.I attachport
Xwithout a controlling terminal in the first place.
X.TP
X.I warning: cannot dissociate /dev/tty
X.I attachport
Xwill not be able to dissociate itself from your terminal.
X.TP
X.I cannot confirm connection
X.I attachport
Xis unable to access
XTCP status information for the connection.
XThis shouldn't happen;
Xlet your system administrator
Xand travel agent know if it does.
X.TP
X.I cannot allocate environment
XThere's so little memory available that
X.I attachport
Xis unable to find space for
Xthe REMOTE and PROTO environment variables.
XIf REMOTE and PROTO are in the environment
Xwhen
X.I attachport
Xstarts,
Xthis can't happen,
Xand
X.I attachport
Xwill run just a tiny bit faster.
X(On the other hand, most other programs
Xwill run a tiny bit slower.)
X.TP
X.I cannot get socket name
XThis shouldn't happen.
X.TP
X.I local port locked
X.I attachport
Xis set up incorrectly.
X.TP
X.I attached to port nnnnn
X.I attachport
Xhas successfully attached itself to a port,
Xand you specified
X.B\-v.
X.TP
X.I cannot execute
X.I attachport
Xis unable to start the server.
X.TP
X.I local port locked
X.I attachport
Xis set up incorrectly.
X.TP
X.I warning: cannot unlink authentication entry
XThis should never happen;
Xif it does, report the problem to your system administrator
Xand make sure the entry is removed.
X.TP
X.I warning: cannot authenticate
X.I attachport
Xis set up incorrectly.
X.SH MACHINES
X.I attachport
Xhas been tested on a VAX 8700 running ULTRIX 2.0,
Xa Sun 3 running SunOS,
Xa Sun 4 running SunOS,
Xa Convex C-210 running Convex UNIX,
Xan Astronautics ZS-2 running ZSUnix,
Xand several other machines.
X.SH FILES
XNone.
X.SH BUGS
XNone known.
X.SH RESTRICTIONS
X.I attachport
Xdoes not let you easily specify a pipeline or other sequence
Xof commands; you must first set up an executable shell script
Xthat does the desired combination of actions.
X.PP
X.I attachport
Xdeals correctly but rigidly with multihomed hosts.
X.PP
X.I attachport
Xdoes not support
X.I syslog.
X.PP
XBecause of failures in the signal handling semantics,
X.I attachport
Xmay fail to notice a child exiting if too many children
Xexit at once. Normally this doesn't matter, but if
X.I attachport
Xis withering away under
X.B\-1
Xor
X.I killaport,
Xit may stick around waiting for nothing.
X.I attachport
Xchecks for this condition and corrects it periodically.
X.PP
XIf
X.I program
Xforks and exits,
Xpassing the connection to its children,
Xit will lose authentication.
XThis is consistent with other network programs and
Xwith common sense: it's impossible to define
X``the'' user on the other side of the connection if
Xseveral processes, all with different uids, have that
Xconnection open.
X.SH VERSION
Xattachport version 4.1, dated April 18, 1990.
X.SH AUTHOR
XCopyright 1990, Daniel J. Bernstein.
X.SH "SEE ALSO"
Xauthtcp(1),
Xkillaport(1),
Xtelnet(1),
Xauthuser(3),
Xgetservbyname(3),
Xauthd(8),
Xinetd(8)
END_OF_FILE
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if test -f 'authd.c' -a "${1}" != "-c" ; then
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else
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sed "s/^X//" >'authd.c' <<'END_OF_FILE'
X/*
Xauthd.c: Authentication Server daemon
X*/
X
Xstatic char authdauthor[] =
X"authd was written by Daniel J. Bernstein.\n\
XInternet address: [e-mail].\n";
X
Xstatic char authdversion[] =
X"authd version 2.1, April 18, 1990.\n\
XCopyright (c) 1990, Daniel J. Bernstein.\n\
XAll rights reserved.\n";
X
Xstatic char authdcopyright[] =
X"authd version 2.1, April 18, 1990.\n\
XCopyright (c) 1990, Daniel J. Bernstein.\n\
XAll rights reserved.\n\
X\n\
XUntil January 1, 1995, you are granted the following rights: A. To make\n\
Xcopies of this work in original form, so long as (1) the copies are exact\n\
Xand complete; (2) the copies include the copyright notice, this paragraph,\n\
Xand the disclaimer of warranty in their entirety. B. To distribute this\n\
Xwork, or copies made under the provisions above, so long as (1) this is\n\
Xthe original work and not a derivative form; (2) you do not charge a fee\n\
Xfor copying or for distribution; (3) you ensure that the distributed form\n\
Xincludes the copyright notice, this paragraph, and the disclaimer of\n\
Xwarranty in their entirety. These rights are temporary and revocable upon\n\
Xwritten, oral, or other notice by Daniel J. Bernstein. These rights are\n\
Xautomatically revoked on January 1, 1995. This copyright notice shall be\n\
Xgoverned by the laws of the state of New York.\n\
X\n\
XIf you have questions about authd or about this copyright notice,\n\
Xor if you would like additional rights beyond those granted above,\n\
Xplease feel free to contact the author at [e-mail]\n\
Xon the Internet.\n";
X
Xstatic char authdwarranty[] =
X"To the extent permitted by applicable law, Daniel J. Bernstein disclaims\n\
Xall warranties, explicit or implied, including but not limited to the\n\
Ximplied warranties of merchantability and fitness for a particular purpose.\n\
XDaniel J. Bernstein is not and shall not be liable for any damages,\n\
Xincidental or consequential, arising from the use of this program, even\n\
Xif you inform him of the possibility of such damages. This disclaimer\n\
Xshall be governed by the laws of the state of New York.\n\
X\n\
XIn other words, use this program at your own risk.\n\
X\n\
XIf you have questions about authd or about this disclaimer of warranty,\n\
Xplease feel free to contact the author at [e-mail]\n\
Xon the Internet.\n";
X
Xstatic char authdusage[] =
X"Usage: authd [ -ACHUVW ] \n\
XHelp:  authd -H\n";
X
Xstatic char authdhelp[] =
X"authd provides TCP authentication information to other Internet hosts. \n\
X\n\
Xauthd -A: print authorship notice\n\
Xauthd -C: print copyright notice\n\
Xauthd -H: print this notice\n\
Xauthd -U: print short usage summary\n\
Xauthd -V: print version number\n\
Xauthd -W: print disclaimer of warranty\n\
X\n\
Xauthd: provide authentication information as per RFC 931\n\
X\n\
Xauthd should be run under a TCP connection server, such as\n\
Xinetd(8) or attachport(1).\n\
X\n\
XIf you have questions about or suggestions for authd, please feel free\n\
Xto contact the author, Daniel J. Bernstein, at [e-mail]\n\
Xon the Internet.\n";
X
X#include <stdio.h>
Xextern int errno;
X#include <sys/types.h>
X#include <netinet/in.h>
X#include <sys/file.h>
X#ifdef BSD
X#include <limits.h>
X#endif
Xextern int getopt();
Xextern char *optarg; /* these should be in getopt.h! */
Xextern int optind;
X#include <ctype.h>
X#include "djberr.h"
X
X#ifndef AUTHDIR
X#define AUTHDIR "/usr/etc/auth"
X#endif
X
X#define ERR(num) { printf("%s, %s: ERROR: UNKNOWN-ERROR\r\n",\
X                          localport,remoteport); exit(num); }
X
Xmain(argc,argv,envp)
Xint argc;
Xchar *argv[];
Xchar *envp[];
X{
X int ch;
X char localport[10];
X int localportlen = 0;
X char remoteport[10];
X int remoteportlen = 0;
X int loop = 0;
X struct sockaddr_in sa;
X int salen;
X int authfd;
X char authfn[sizeof(AUTHDIR) + 30];
X int lockfd;
X char lockfn[sizeof(AUTHDIR) + 30]; /* for new locking protocol */
X char lockbuf[32]; /* 5 pid, 1 :, 10 I, 1 ., 5 R, 1 \n, 8 U, 1 \0 */
X unsigned long lockin;
X unsigned short lockport;
X int r;
X char buf[9];
X int opt;
X
X while ((opt = getopt(argc,argv,"ACHUVW")) != EOF)
X   switch(opt)
X    {
X     case 'A': (void) err(authdauthor); exit(1);
X     case 'C': (void) err(authdcopyright); exit(1);
X     case 'H': (void) err(authdhelp); exit(1);
X     case 'U': (void) err(authdusage); exit(1);
X     case 'V': (void) err(authdversion); exit(1);
X     case 'W': (void) err(authdwarranty); exit(1);
X     case '?': (void) err(authdusage); exit(1);
X    }
X argv += optind, argc -= optind;
X if (*argv)
X  {
X   (void) err(authdusage); exit(1);
X  }
X
X while ((ch = getchar()) != ',')
X  {
X   if (isascii(ch) && isdigit(ch))
X     localport[localportlen++] = ch;
X   if (localportlen == 6) /* tough luck! */
X     exit(2);
X   if ((++loop) > 1000) /* tough luck! */
X     exit(3);
X  }
X
X while ((ch = getchar()) != '\n')
X  {
X   if (isascii(ch) && isdigit(ch))
X     remoteport[remoteportlen++] = ch;
X   if (remoteportlen == 6) /* tough luck! */
X     exit(4);
X   if ((++loop) > 1000) /* tough luck! */
X     exit(5);
X  }
X
X /* Now we'll be nice enough to respond. */
X
X salen = sizeof(sa);
X if (getpeername(0,&sa,&salen) == -1) ERR(6)
X
X /* Now we have enough information to look up answer. */
X
X (void) sprintf(lockfn,"%s/tcp/lock.%s",AUTHDIR,localport);
X if ((lockfd = open(lockfn,O_RDONLY)) == -1) ERR(7)
X (void) flock(lockfd,LOCK_EX); /* can't fail */
X if ((r = read(lockfd,lockbuf,31)) <= 0) ERR(8)
X lockbuf[r] = '\0';
X if (lockbuf[0] == '!') ERR(12) /* ding ding ding! security alert! */
X
X (void) sprintf(authfn,"%s/tcp/%D.%s.%s",AUTHDIR,sa.sin_addr.s_addr,
X                localport,remoteport);
X if ((authfd = open(authfn,O_RDONLY)) == -1)
X  {
X   /* maybe it's authtcp and username file isn't there yet */
X   if (sscanf(lockbuf,"%*d:%D.%hd %8s",&lockin,&lockport,buf) < 3) ERR(9)
X   if ((lockin != sa.sin_addr.s_addr) || (lockport != atoi(remoteport))) ERR(10)
X   /* bingo! */
X  }
X else
X  {
X   if ((r = read(authfd,buf,8)) <= 0) ERR(11)
X   buf[r] = '\0';
X  }
X
X printf("%s, %s: USERID: UNIX: %s\r\n",localport,remoteport,buf);
X
X (void) flock(lockfd,LOCK_UN); /* unnecessary */
X exit(0);
X}
END_OF_FILE
if test 6057 -ne `wc -c <'authd.c'`; then
    echo shar: \"'authd.c'\" unpacked with wrong size!
fi
# end of 'authd.c'
fi
if test -f 'authd.man' -a "${1}" != "-c" ; then
  echo shar: Will not clobber existing file \"'authd.man'\"
else
echo shar: Extracting \"'authd.man'\" \(2244 characters\)
sed "s/^X//" >'authd.man' <<'END_OF_FILE'
X.TH authd 8
X.SH NAME
Xauthd \- Authentication Server daemon
X.SH SYNTAX
Xauthd
X[
X\fB\-ACHUVW\fI
X]
X.SH DESCRIPTION
X.I authd
Xis a simple daemon implementing the
XRFC 931 Authentication Server protocol.
XIt should be invoked by a network server,
Xsuch as
X.I attachport(1),
Xfor connections to TCP port 113.
X.PP
XThe client host
Xgives
X.I authd
Xtwo numbers separated by a comma.
X.I authd
Xinterprets the numbers as TCP port numbers
Xfor the local and remote sides respectively
Xof a TCP connection between this host and the client host.
XIt returns a line of the form
X.EX
Xlocalport, remoteport: USERID: UNIX: username
X.EE
Xwhere username
Xis the name of the user on this side of
Xthe specified connection.
XIf
X.I authd
Xdoes not have an authentication entry for that connection,
Xit returns a line of the form
X.EX
Xlocalport, remoteport: ERROR: UNKNOWN-ERROR.
X.EE
X.PP
XOptions
X.B ACHUVW
Xprint the authorship notice,
Xcopyright notice,
Xhelp notice,
Xshort usage summary,
Xversion number,
Xand warranty information respectively.
X.PP
X.SH DIAGNOSTICS
X.TP
XNone.
X.SH MACHINES
X.I authd
Xhas been tested
Xon an Astronautics ZS-2
Xrunning ZSUnix,
Xa Sun 3 running SunOS,
Xa Sun 4 running SunOS,
Xa Convex C-210 running Convex UNIX,
Xand several other machines.
X.SH FILES
X/usr/etc/auth/tcp/*
X.SH BUGS
XNone known.
X.SH RESTRICTIONS
X.I authd
Xdoes not require kernel support;
Xit must be supported on the user level by
X.I authtcp
Xand
X.I attachport.
XIf those programs are not used,
X.I authd
Xis useless.
X.PP
XThe author feels quite confident in predicting that
Xthe first problems people have with
X.I authd
Xwill be on multihomed hosts.
XProgrammers be warned: It takes some effort
Xto correctly use
X.I authd
Xon a multihomed host!
X.SH VERSION
Xauthd version 2.1, dated April 18, 1990.
X.SH AUTHOR
XCopyright 1990, Daniel J. Bernstein.
X.SH REFERENCES
XThe authentication server is more secure than passwords
Xin some ways, but less secure than passwords in many ways.
X(It's certainly better than no password at all---e.g., for
Xmail or news.)
XIt is not the final solution.
XFor an excellent discussion of security problems within
Xthe TCP/IP protocol suite, see
XSteve Bellovin's article
X``Security Problems in the TCP/IP Protocol Suite.''
X.SH "SEE ALSO"
Xauthtcp(1),
Xattachport(1),
Xauthuser(3),
Xtcp(4),
Xinetd(8)
END_OF_FILE
if test 2244 -ne `wc -c <'authd.man'`; then
    echo shar: \"'authd.man'\" unpacked with wrong size!
fi
# end of 'authd.man'
fi
if test -f 'authtcp.man' -a "${1}" != "-c" ; then
  echo shar: Will not clobber existing file \"'authtcp.man'\"
else
echo shar: Extracting \"'authtcp.man'\" \(6629 characters\)
sed "s/^X//" >'authtcp.man' <<'END_OF_FILE'
X.TH authtcp 1
X.SH NAME
Xauthtcp \- create a locally authenticated TCP connection
X.SH SYNTAX
Xauthtcp
X[
X\fB\-d\fIn
X] [
X\fB\-p\fIlocalport
X] [
X\fB\-rRxXv\fI
X] [
X\fB\-ACHUVW\fI
X]
X\fIinetaddr\fB
X\fItcpport\fB
X\fIprogram\fB
X[
X\fIarg ...\fB
X]
X.SH DESCRIPTION
X.I authtcp
Xcreates a TCP connection to Internet host
X\fIinetaddr\fB
Xat port
X\fItcpport\fB,
Xthen runs
X\fIprogram\fB
Xwith the specified
Xarguments.
XThe local TCP port may be given as
X\fIlocalport\fB,
Xor
X.I authtcp
Xwill assign one.
X.PP
XUntil
X.I program
Xexits,
X.I authd(8)
Xwill report that the user owns the TCP connection.
XHence the other end of the connection can
Xverify the identity of this end,
Xmodulo the lack of Internet security.
X.PP
X.I inetaddr
Xcan be fully specified as a dotted Internet address,
Xor given as a domain name.
X.I tcpport
Xcan be fully specified as a decimal port number,
Xor given as a service name.
X.PP
X.I authtcp
Xmakes the connection available
Xto
X.I program
Xas a socket in file descriptor 6,
Xleaving all other file descriptors intact.
X.PP
XOptions
X.B ACHUVW
Xprint the authorship notice,
Xcopyright notice,
Xhelp notice,
Xshort usage summary,
Xversion number,
Xand warranty information respectively.
X.PP
X.I authtcp
Xhas several flags:
X.TP 12
X\fB\-d\fIn
XProvide the connection in file descriptor
X\fIn\fB,
Xrather than the default descriptor, 6.
XIf
X\fIn\fB
Xis not specified,
X.I authtcp
Xwill open the connection in the first available file descriptor
Xand pass that number in place of the first argument to
X.I program
Xthat contains solely an equals sign (if there is one).
X.TP
X\fB\-p\fIlocalport
XAttempt to use
X.I localport
Xas the local TCP port number.
XThis may fail if that port number is out of
Xrange (usually 1\-65535),
Xor if another process is using that port
X(or has used it very recently).
XPorts 1 through 1023 are generally reserved for root processes,
Xand ports above 50000 are generally reserved for user servers.
XIf you specify
X.B \-p0
X(default),
X.I authtcp
Xwill assign a number.
XSeveral instances of
X.B \-p
Xdefer to the last.
X.TP
X\fB\-X\fI
XDo not attempt to locally authenticate the connection;
Xjust set up the connection and run
X.I program.
X.TP
X\fB\-x\fI
XLocally authenticate the connection (default).
X.TP
X\fB\-r\fI
XAttempt to determine the identity of the other end of
Xthis connection
Xthrough the remote Authentication Server (default).
X.I authtcp
Xwill place the identity
Xinto environment variable
XREMOTE, with the form
X.I [e-mail]
Xwhere
X.I user
Xis a string giving the user name
Xand
X.I in.et.ad.dr
Xis a numerical Internet address.
XIf the other end is not authenticated,
X.I user
Xwill be blank.
XNote that
X.I user
Xmay contain @ signs;
XREMOTE should be parsed from
Xright to left.
X.I authtcp
Xalso sets environment variable
XPROTO to the string
X.I TCP.
X.TP
X\fB\-R\fI
XDo not remotely authenticate.
X.TP
X\fB\-v\fI
XVerbose: Print a message when the connection is established.
XAlso, report unusual termination of
X.I program.
X.PP
XIf
X.I program
Xterminates normally,
X.I authtcp
Xwill terminate with the same exit code.
XOtherwise it will terminate with exit code 1.
X.PP
X.SH DIAGNOSTICS
X.TP
X.I do not understand inetaddr
XYou probably specified a domain name address
Xthat
X.I authtcp
Xcan't decode.
X.TP
X.I cannot execute
X.I authtcp
Xis unable to execute
X.I program.
X.TP
X.I cannot unlink authentication entry
XThis should never happen; if it does,
Xreport the problem to your system administrator and
Xmake sure the entry is removed.
X.TP
X.I cannot bind local port
XYou probably specified a protected or out-of-range
Xport with
X.I\-p.
XIf you didn't specify
X.I\-p
Xand this message appears without a number,
Xall TCP ports are in use.
XReport this to your system administrator.
X.TP
X.I cannot confirm connection
X.I authtcp
Xis unable to access
XTCP status information for the connection.
XThis shouldn't happen;
Xlet your system administrator
Xand travel agent know if it does.
X.TP
X.I cannot allocate environment
XThere's so little memory available that
X.I authtcp
Xis unable to find space for
Xthe REMOTE and PROTO environment variables.
XIf REMOTE and PROTO are in the environment
Xwhen
X.I authtcp
Xstarts,
Xthis can't happen,
Xand
X.I authtcp
Xwill run just a tiny bit faster.
X(On the other hand, most other programs
Xwill run a tiny bit slower.)
X.TP
X.I cannot connect
XSelf-explanatory.
X.TP
X.I connected to
XSelf-explanatory.
X.TP
X.I killed by signal
XSelf-explanatory.
X.TP
X.I cannot authenticate
X.I authtcp
Xis not set up correctly.
X.TP
X.I local port locked
X.I authtcp
Xis not set up correctly.
X.TP
X.I cannot setreuid
XThis should never happen.
X.TP
X.I cannot create socket
XThis shouldn't happen, unless you have too many files open.
X.TP
X.I cannot use file descriptor
XThis should never happen.
X.TP
X.I cannot get socket name
XThis shouldn't happen.
X.SH MACHINES
X.I authtcp
Xhas been tested
Xon an Astronautics ZS-2
Xrunning ZSUnix,
Xa Sun 3 running SunOS,
Xa Sun 4 running SunOS,
Xa Convex C-210 running Convex UNIX,
Xand several other machines.
X.SH FILES
X/usr/etc/auth/tcp/*
X.SH BUGS
XNone known.
X.SH RESTRICTIONS
XIf
X.I program
Xcloses the connection long before exiting,
Xanother user can with a little effort make the same connection
Xand pretend to be the user running
X.I authtcp.
XHence
X.I program
Xshould exit soon after
Xclosing the connection.
X(Within several seconds is usually good enough.)
XA slightly more subtle
Xsecurity problem is that a program may set up a connection
Xunder
X.I authtcp,
Xbreak the connection without exiting,
Xand wait for a victim program to make the same connection.
XIf the attacker chose the correct local port number,
Xthere are two possibilities: Either the victim uses
Xthe authentication mechanism and will fail to connect,
Xor the victim does not understand the mechanism and will
Xbe misrepresented by
X.I authd.
XAs of version 1.5,
X.I authtcp
Xcloses both of these holes,
Xby keeping the connection open until
X.I program
Xexits.
XHence
X.I program
Xmust not depend upon the connection being closed
Xbefore it exits.
X.PP
X.I authtcp's
Xmost important function is to create a locally authenticated
Xconnection; remote authentication is useful but can be
Xperformed by
X.I program.
XIt is sometimes difficult to explain that the
X.I auth
Xin
X.I authtcp
Xstands for local, not remote, authentication.
X.PP
XIf
X.I gethostbyname(3)
Xdoesn't understand the Domain Name Server,
X.I authtcp
Xwon't either.
X.PP
X.I authtcp
Xshould try all the possible addresses returned
Xby
X.I gethostbyname(3);
Xit only tries the first.
X.PP
XIf
X.I program
Xpasses the connection to another
Xprocess and exits,
Xauthentication will be lost.
X.SH VERSION
Xauthtcp version 2.1, dated April 18, 1990.
X.SH AUTHOR
XCopyright 1990, Daniel J. Bernstein.
X.SH "SEE ALSO"
Xattachport(1),
Xauthuser(3),
Xtcp(4),
Xauthd(8),
Xgethostbyname(3),
Xgetservbyname(3)
END_OF_FILE
if test 6629 -ne `wc -c <'authtcp.man'`; then
    echo shar: \"'authtcp.man'\" unpacked with wrong size!
fi
# end of 'authtcp.man'
fi
if test -f 'authuser.c' -a "${1}" != "-c" ; then
  echo shar: Will not clobber existing file \"'authuser.c'\"
else
echo shar: Extracting \"'authuser.c'\" \(6556 characters\)
sed "s/^X//" >'authuser.c' <<'END_OF_FILE'
Xchar authuserauthor[] =
X"authuser was written by Daniel J. Bernstein.\n\
XInternet address: [e-mail].\n";
X
Xchar authuserversion[] =
X"authuser version 2.0, April 2, 1990.\n\
XCopyright (c) 1990, Daniel J. Bernstein.\n\
XAll rights reserved.\n";
X
Xchar authusercopyright[] =
X"authuser version 2.0, April 2, 1990.\n\
XCopyright (c) 1990, Daniel J. Bernstein.\n\
XAll rights reserved.\n\
X\n\
XUntil January 1, 1993, you are granted the following rights: A. To make\n\
Xcopies of this work in original form, so long as (1) the copies are exact\n\
Xand complete; (2) the copies include the copyright notice, this paragraph,\n\
Xand the disclaimer of warranty in their entirety. B. To distribute this\n\
Xwork, or copies made under the provisions above, so long as (1) this is\n\
Xthe original work and not a derivative form; (2) you do not charge a fee\n\
Xfor copying or for distribution; (3) you ensure that the distributed form\n\
Xincludes the copyright notice, this paragraph, and the disclaimer of\n\
Xwarranty in their entirety. These rights are temporary and revocable upon\n\
Xwritten, oral, or other notice by Daniel J. Bernstein. These rights are\n\
Xautomatically revoked on January 1, 1993. This copyright notice shall be\n\
Xgoverned by the laws of the state of New York.\n\
X\n\
XIf you have questions about authuser or about this copyright notice,\n\
Xor if you would like additional rights beyond those granted above,\n\
Xplease feel free to contact the author at [e-mail]\n\
Xon the Internet.\n";
X
Xchar authuserwarranty[] =
X"To the extent permitted by applicable law, Daniel J. Bernstein disclaims\n\
Xall warranties, explicit or implied, including but not limited to the\n\
Ximplied warranties of merchantability and fitness for a particular purpose.\n\
XDaniel J. Bernstein is not and shall not be liable for any damages,\n\
Xincidental or consequential, arising from the use of this program, even\n\
Xif you inform him of the possibility of such damages. This disclaimer\n\
Xshall be governed by the laws of the state of New York.\n\
X\n\
XIn other words, use this program at your own risk.\n\
X\n\
XIf you have questions about authuser or about this disclaimer of warranty,\n\
Xplease feel free to contact the author at [e-mail]\n\
Xon the Internet.\n";
X
Xchar authuserhelp[] =
X"#include \"authuser.h\"\n\
X\n\
Xint auth_casecmp(u,v); char *u; char *v;\n\
XReturns 0 if strings are equal, 1 if the first is larger, -1 if the\n\
Xsecond is larger. Case is ignored.\n\
X\n\
Xchar *auth_xline(user,fd,&in);\n\
XReturns line like X-Auth-User: username or X-Forgery-By: username,\n\
Xdepending what the host on the other side of fd thinks of the user.\n\
X\n\
Xint auth_fd(fd,&in,&local,&remote);\n\
XPlaces address information for TCP connection fd into in, local, remote.\n\
X\n\
Xchar *auth_tcpuser(in,local,remote);\n\
XReturns name of user on remote@in side of local TCP connection.\n\
X\n\
Xchar *user; int fd; unsigned long in; unsigned short local, remote;\n\
X\n\
XIf you have questions about or suggestions for authuser, please feel free\n\
Xto contact the author, Daniel J. Bernstein, at [e-mail]\n\
Xon the Internet.\n";
X
X#include <stdio.h>
X#include <sys/types.h>
X#include <sys/socket.h>
X#include <netinet/in.h>
X#include <arpa/inet.h>
X#include <netdb.h>
X#include <sys/errno.h>
Xextern int errno;
X#include <ctype.h>
X#include "authuser.h"
X
X#ifndef AUTHTCPPORT
X#define AUTHTCPPORT 113
X#endif
X
X#define SIZ 500 /* various buffers */
X
Xint auth_casecmp(u,v)
Xchar *u;
Xchar *v;
X{
X /* is it correct to consider Foo and fOo the same user? yes */
X while (*u && *v)
X   if (tolower(*u) != tolower(*v))
X     return(tolower(*u) - tolower(*v));
X   else
X     u++,v++;
X return(*u || *v);
X}
X
Xstatic char authline[SIZ];
X
Xchar *auth_xline(user,fd,in)
Xchar *user; /* the supposed name of the user, NULL if unknown */
Xint fd; /* the file descriptor of the connection */
Xunsigned long *in;
X{
X unsigned short local;
X unsigned short remote;
X char *ruser;
X
X if (auth_fd(fd,in,&local,&remote) == -1)
X   return NULL;
X ruser = auth_tcpuser(*in,local,remote);
X if (ruser == NULL)
X   return(NULL);
X if (user == NULL)
X   user = ruser; /* forces X-Auth-User */
X sprintf(authline,
X     (auth_casecmp(ruser,user) ? "X-Forgery-By: %s" : "X-Auth-User: %s"),
X     ruser);
X return(authline);
X}
X
Xint auth_fd(fd,in,local,remote)
Xint fd;
Xunsigned long *in;
Xunsigned short *local;
Xunsigned short *remote;
X{
X struct sockaddr_in sa;
X int dummy;
X
X dummy = sizeof(sa);
X if (getsockname(fd,&sa,&dummy) == -1)
X   return -1;
X if (sa.sin_family != AF_INET)
X  {
X   errno = EAFNOSUPPORT;
X   return -1;
X  }
X *local = ntohs(sa.sin_port);
X dummy = sizeof(sa);
X if (getpeername(fd,&sa,&dummy) == -1)
X   return -1;
X *remote = ntohs(sa.sin_port);
X *in = sa.sin_addr.s_addr;
X return 0;
X}
X
Xstatic char ruser[SIZ];
Xstatic char realbuf[SIZ];
Xstatic char *buf;
X
Xchar *auth_tcpuser(in,local,remote)
Xunsigned long in;
Xunsigned short local;
Xunsigned short remote;
X{
X struct sockaddr_in sa;
X int s;
X int buflen;
X int w;
X int saveerrno;
X char ch;
X unsigned short rlocal;
X unsigned short rremote;
X
X if ((s = socket(AF_INET,SOCK_STREAM,0)) == -1)
X   return(NULL);
X sa.sin_family = AF_INET;
X sa.sin_port = htons((unsigned short) AUTHTCPPORT);
X sa.sin_addr.s_addr = in;
X if (connect(s,&sa,sizeof(sa)) == -1)
X  {
X   saveerrno = errno;
X   (void) close(s);
X   errno = saveerrno;
X   return(NULL);
X  }
X
X buf = realbuf;
X (void) sprintf(buf,"%u , %u\r\n",(unsigned int) remote,(unsigned int) local);
X /* note the reversed order */
X buflen = strlen(buf);
X while ((w = write(s,buf,buflen)) < buflen)
X   if (w == -1) /* should we worry about 0 as well? */
X    {
X     saveerrno = errno;
X     (void) close(s);
X     errno = saveerrno;
X     return(NULL);
X    }
X   else
X    {
X     buf += w;
X     buflen -= w;
X    }
X buf = realbuf;
X while ((w = read(s,&ch,1)) == 1)
X  {
X   *buf = ch;
X   if ((ch != ' ') && (ch != '\t') && (ch != '\r'))
X     buf++;
X   if ((buf - realbuf == sizeof(realbuf) - 1) || (ch == '\n'))
X     break;
X  }
X if (w == -1)
X  {
X   saveerrno = errno;
X   (void) close(s);
X   errno = saveerrno;
X   return(NULL);
X  }
X *buf = '\0';
X
X if (sscanf(realbuf,"%hd,%hd: USERID :%*[^:]:%s",
X            &rremote,&rlocal,ruser) < 3)
X  {
X   (void) close(s);
X   errno = EIO;
X   /* makes sense, right? well, not when USERID failed to match ERROR */
X   /* but there's no good error to return in that case */
X   return(NULL);
X  }
X if ((remote != rremote) || (local != rlocal))
X  {
X   (void) close(s);
X   errno = EIO;
X   return(NULL);
X  }
X /* XXXXXX: we're not going to do any backslash processing */
X (void) close(s);
X return(ruser);
X}
END_OF_FILE
if test 6556 -ne `wc -c <'authuser.c'`; then
    echo shar: \"'authuser.c'\" unpacked with wrong size!
fi
# end of 'authuser.c'
fi
if test -f 'authuser.h' -a "${1}" != "-c" ; then
  echo shar: Will not clobber existing file \"'authuser.h'\"
else
echo shar: Extracting \"'authuser.h'\" \(279 characters\)
sed "s/^X//" >'authuser.h' <<'END_OF_FILE'
X#ifndef AUTHUSER_H
X#define AUTHUSER_H
X
Xextern char authuserauthor[];
Xextern char authuserversion[];
Xextern char authusercopyright[];
Xextern char authuserwarranty[];
Xextern char authuserhelp[];
X
Xint auth_casecmp();
Xchar *auth_xline();
Xint auth_fd();
Xchar *auth_tcpuser();
X
X#endif
END_OF_FILE
if test 279 -ne `wc -c <'authuser.h'`; then
    echo shar: \"'authuser.h'\" unpacked with wrong size!
fi
# end of 'authuser.h'
fi
if test -f 'authuser.man' -a "${1}" != "-c" ; then
  echo shar: Will not clobber existing file \"'authuser.man'\"
else
echo shar: Extracting \"'authuser.man'\" \(3314 characters\)
sed "s/^X//" >'authuser.man' <<'END_OF_FILE'
X.TH authuser 3
X.SH NAME
Xauthuser \- remote authentication library using the Authentication Server
X.SH SYNTAX
X.B #include <authuser.h>
X.PP
X.B int auth_casecmp(u,v);
X.br
X.B char *u;
X.br
X.B char *v;
X.PP
X.B char *auth_xline(user,fd,&in);
X.PP
X.B int auth_fd(fd,&in,&local,&remote);
X.PP
X.B char *auth_tcpuser(in,local,remote);
X.PP
X.B char *user;
X.br
X.B int fd;
X.br
X.B unsigned long in;
X.br
X.B unsigned short local;
X.br
X.B unsigned short remote;
X.SH DESCRIPTION
XThe
X.I authuser
Xlibrary provides a simple interface for
Xfinding out the remote identity
Xof a connection through the
XAuthentication Server
Xas specified by RFC 931.
X.PP
XStatic strings
X.B authuserauthor[],
X.B authuserversion[],
X.B authusercopyright[],
X.B authuserwarranty[],
Xand
X.B authuserhelp[]
Xcontain the authorship notice,
Xversion number,
Xcopyright notice,
Xwarranty information,
Xand help notice respectively.
X.PP
X.B auth_casecmp(u,v)
Xreturns 0 if the strings are equal, 1 if the first is larger,
X-1 if the second is larger. Case is ignored.
X.PP
X.B auth_xline(user,fd,&in)
Xreturns a line of the form X-Auth-User: username or X-Forgery-By: username,
Xdepending upon what the host on the other side of
X.B fd
Xthinks of the user.
XThis is particularly appropriate for
Xmail and news headers.
XThe line is stored in a static area
Xwhich is overwritten on each call to
X.B auth_xline.
XIf
X.B fd
Xis not a TCP connection
Xor authentication is impossible,
X.B auth_xline
Xreturns NULL, setting errno appropriately.
XIf user is NULL,
Xit never returns X-Forgery-By.
XThe line is not cr-lf terminated.
X.B auth_xline
Xplaces the Internet address of the other host into in.
X.PP
X.B auth_fd(fd,&in,&local,&remote)
Xretrieves address information from the connection in socket
X.B fd.
XIt places the
XInternet address of the host on other side into
X.B in
Xand the local and remote
XTCP ports into
X.B local
Xand
X.B remote.
X.B auth_fd
Xreturns -1 upon error, setting errno appropriately.
X.PP
X.B auth_tcpuser(in,local,remote)
Xreturns the name of the user on the other end of the TCP connection
Xbetween
X.B remote@in
Xand
X.B local.
XIf authentication is impossible,
X.B auth_tcpuser
Xreturns
XNULL, setting errno appropriately.
XThe user name is stored in a static area
Xwhich is overwritten on each call to
X.B auth_tcpuser
Xand
X.B auth_xline.
X.PP
X.SH MACHINES
X.I authuser
Xhas been tested
Xon an Astronautics ZS-2
Xrunning ZSUnix,
Xa Sun 3 running SunOS, a Sun 4 running SunOS,
Xa Convex C-210 running Convex UNIX,
Xand several other machines.
X.SH RESTRICTIONS
X.I authuser
Xdoes no backslash interpretation
Xupon the remote user name.
XHopefully the next revision of RFC 931
Xwill make clear exactly what backslash
Xinterpretation should be going on.
X.PP
X.I authuser
Xdoes not use the operating system type
Xinformation provided by the Authentication Server.
X.SH VERSION
Xauthuser version 2.0, dated April 2, 1990.
X.SH AUTHOR
XCopyright 1990, Daniel J. Bernstein.
X.SH REFERENCES
XThe authentication server is more secure than passwords
Xin some ways, but less secure than passwords in many ways.
X(It's certainly better than no password at all---e.g., for
Xmail or news.)
XIt is not the final solution.
XFor an excellent discussion of security problems within
Xthe TCP/IP protocol suite, see
XSteve Bellovin's article
X``Security Problems in the TCP/IP Protocol Suite.''
X.SH "SEE ALSO"
Xauthtcp(1),
Xauthd(1),
Xattachport(1),
Xtcp(4)
END_OF_FILE
if test 3314 -ne `wc -c <'authuser.man'`; then
    echo shar: \"'authuser.man'\" unpacked with wrong size!
fi
# end of 'authuser.man'
fi
if test -f 'dir.doc' -a "${1}" != "-c" ; then
  echo shar: Will not clobber existing file \"'dir.doc'\"
else
echo shar: Extracting \"'dir.doc'\" \(3911 characters\)
sed "s/^X//" >'dir.doc' <<'END_OF_FILE'
XThe authentication directory, AUTHDIR/tcp, contains several different
Xtypes of files.
X
XIt is assumed that long ints representing Internet addresses take at
Xmost ten digits, short ints representing TCP port numbers take at most
Xfive digits, and ints representing process ids take at most five digits.
X
XFiles of the form I.L.R, where I, L, and R are integers, are username
Xfiles. There is one username file per auth connection to/from this host,
Xtwo for a local connection. I is the Internet address of the host on the
Xother end of a TCP connection, expressed as a single long int; L and R
Xare the connection's local and remote TCP ports respectively. The file
Xcontains just the name of the user, up to eight characters long.
X
XFiles of the form ps.C.P, where C and P are integers, are attachport
Xprocess files. There is one process file for each connection served by
Xan attachport on this host. C and P are the process ids of the child
X(server for a particular connection) and parent (attachport) processes
Xrespectively. The file contains the name of a username file; in effect,
Xit points to the username file, so that the attachport can easily keep
Xtrack of each of its children.
X
XFiles of the form lock.L, where L is an integer, are lock files. L is
Xa local TCP port number. At any time there will be at most one auth
Xprogram handling connections to/from port L. When authtcp or attachport
Xstarts, it opens the lock file with O_EXCL and writes its pid into it.
XIf that fails, it reads the lock file, checks that the process exists,
Xand gives an appropriate error. When it exits, it removes the lock file.
X
XLock files are also used to prevent race conditions during critical
Xmoments between connecting or accepting a connection and creating the
Xappropriate username file. For attachport this is no big deal: it
Xselects for reading before accepting a connection, and from before the
Xaccept() until the authentication entry is in place, it places an
Xexclusive flock() on the lock file. (This WILL NOT WORK if selecting
Xfor reading performs an implicit accept. The race condition resulting
Xfrom such a bug could be extremely hard to detect; but don't say I
Xdidn't warn you.) For authtcp, however, this is much more difficult:
Xan outgoing connect() may take practically forever, and there's no way
Xto precisely control the moment of connection as a select-accept can.
XOn the other hand, authtcp has all the local authentication information
Xit needs, before even beginning the connection. So it writes a colon,
Xthe I.R remote information, a newline, and the username into the lock
Xfile after its pid; it doesn't use a flock() except while updating the
Xlock file. authd will look in this file only if it fails to find a
Xusername file; authentication requests rarely happen so quickly.
Xattachport also places extra information into the lock file, namely a
Xhyphen and the user name.
X
XObserve that the duplicate authtcp information in the lock file gives
Xaway the user name on the local side of a connection that has not yet
Xsucceeded. Technically, this is not a violation of RFC 931, but it might
Xoffend purists. Then again, it's symmetric with how the user name is
Xavailable for a moment after the connection is closed.
X
XLatest addition to the lock file: If the first character is a ! then
Xattachport (or, in a later version, perhaps authtcp) has been killed by
Xthe user during a critical moment. If you want a detailed explanation of
Xhow and why this is used, ask auth's author.
X
XIf the auth package gets much more complicated, it may be worth imposing
Xa bit more structure on the authentication directory; hopefully all this
Xauthentication information will be available from the kernel long before
Xthat happens. The lock file system would have to be changed immediately
Xif auth were to support REUSEADDR; however, ftp seems to be the only
Xprogram that needs REUSEADDR, and PUFF is a much better file transfer
Xsystem.
END_OF_FILE
if test 3911 -ne `wc -c <'dir.doc'`; then
    echo shar: \"'dir.doc'\" unpacked with wrong size!
fi
# end of 'dir.doc'
fi
if test -f 'djbatoi.h' -a "${1}" != "-c" ; then
  echo shar: Will not clobber existing file \"'djbatoi.h'\"
else
echo shar: Extracting \"'djbatoi.h'\" \(381 characters\)
sed "s/^X//" >'djbatoi.h' <<'END_OF_FILE'
X/* djbatoi.h, 11/1/89. */
X
X#ifndef __DJBATOIH_
X#define __DJBATOIH_
X
X/* some stupid versions of atoi() crash (!) on nulls */
Xint dummyatoi;
X#define atoi(s) ( ( dummyatoi = 0 ), \
X  ( sscanf(s,"%d",&dummyatoi) || ( dummyatoi = 0 ) ), \
X  dummyatoi )
Xlong dummyatol;
X#define atol(s) ( ( dummyatol = 0 ), \
X  ( sscanf(s,"%D",&dummyatol) || ( dummyatol = 0 ) ), \
X  dummyatol )
X
X#endif
END_OF_FILE
if test 381 -ne `wc -c <'djbatoi.h'`; then
    echo shar: \"'djbatoi.h'\" unpacked with wrong size!
fi
# end of 'djbatoi.h'
fi
if test -f 'djberr.h' -a "${1}" != "-c" ; then
  echo shar: Will not clobber existing file \"'djberr.h'\"
else
echo shar: Extracting \"'djberr.h'\" \(491 characters\)
sed "s/^X//" >'djberr.h' <<'END_OF_FILE'
X/* djberr.h, 11/1/89. */
X
X#ifndef __DJBERRH_
X#define __DJBERRH_
X
Xextern int errno;
X
X#define errn(s) (((void) fputs(s,stderr)), putc('\n',stderr))
X#define err(s) (fputs(s,stderr))
X#define errn2(s,t) (((void) fprintf(stderr,s,t)), putc('\n',stderr))
X#define errn3(s,t,u) (((void) fprintf(stderr,s,t,u)), putc('\n',stderr))
X#define perrn2(s,t) { int dummyerrno = errno; (void) fprintf(stderr,s,t); \
X              (void) fputs(": ",stderr); errno = dummyerrno; \
X              (void) perror(""); }
X
X#endif
END_OF_FILE
if test 491 -ne `wc -c <'djberr.h'`; then
    echo shar: \"'djberr.h'\" unpacked with wrong size!
fi
# end of 'djberr.h'
fi
echo shar: End of archive 1 \(of 2\).
cp /dev/null ark1isdone
MISSING=""
for I in 1 2 ; do
    if test ! -f ark${I}isdone ; then
    MISSING="${MISSING} ${I}"
    fi
done
if test "${MISSING}" = "" ; then
    echo You have unpacked both archives.
    rm -f ark[1-9]isdone
else
    echo You still need to unpack the following archives:
    echo "        " ${MISSING}
fi
##  End of shell archive.
exit 0
exit 0 # Just in case...