README revision 22347
122347SpstOPIE Software Distribution, Release 2.3 Important Information 222347Spst======================================= ===================== 322347Spst 422347SpstIntroduction 522347Spst============ 622347Spst 722347Spst "One-time Passwords In Everything" (OPIE) is a freely distributable 822347Spstsoftware package originally developed at and for the US Naval Research 922347SpstLaboratory (NRL). Recent versions are the result of a cooperative effort 1022347Spstbetween of NRL, several of the original NRL authors, The Inner Net, and many 1122347Spstother contributors from the Internet community. 1222347Spst 1322347Spst OPIE is an implementation of the One-Time Password (OTP) System that 1422347Spstis being considered for the Internet standards-track. OPIE provides a one-time 1522347Spstpassword system. The system should be secure against the passive attacks 1622347Spstnow commonplace on the Internet (see RFC 1704 for more details). The system 1722347Spstis vulnerable to active dictionary attacks, though these are not widespread 1822347Spstat present and can be detected through proper use of system audit 1922347Spstsoftware. 2022347Spst 2122347Spst OPIE is primarily written for UNIX-like operating systems, but 2222347Spstwe are working to make applicable portions portable to other operating systems. 2322347SpstThe OPIE software is derived in part from and is fully interoperable with the 2422347SpstBell Communications Research (Bellcore) S/Key Release 1 software. Because 2522347SpstBellcore claims "S/Key" as a trademark for their software, NRL was forced to 2622347Spstuse a different name (we picked "OPIE") for this software distribution. 2722347Spst 2822347Spst OPIE includes the following additions/modifications to the 2922347Spstoriginal Bellcore S/Key(tm) Version 1 software: 3022347Spst 3122347Spst* Just about three command installation (unpack the software, run the 3222347Spst configure script, and run make install). While we still recommend that you 3322347Spst follow instructions and test things by hand, the more adventurous can 3422347Spst install OPIE quickly. 3522347Spst 3622347Spst* A modified BSD FTP daemon that does OTP. 3722347Spst 3822347Spst* A version of su that uses OTP by default. 3922347Spst 4022347Spst* MD5 support. MD5 is now the default algorithm, though MD4 is still supported 4122347Spst by changing a parameter in the Makefile. This change was made because MD5 is 4222347Spst widely believed to be cryptographically stronger than MD4 (see RFC 1321). 4322347Spst 4422347Spst* A more portable version of MD4 has been substituted for the original MD4. 4522347Spst This should solve the endian problems that were in S/Key. 4622347Spst 4722347Spst* Most of the system-dependencies have been moved to a new file "opie_cfg.h". 4822347Spst 4922347Spst* Configuration options have been moved to the Makefile. 5022347Spst 5122347Spst* Isolated system dependencies (e.g. BSDisms) with appropriate #ifdefs. 5222347Spst 5322347Spst* Revised the opiekey(1) program to simultaneously support MD4 and MD5, with 5422347Spst the default algorithm being tunable using the MDX symbol in the Makefile. 5522347Spst 5622347Spst* More operating systems are supported by recent versions of OPIE, but older 5722347Spst BSD systems that aren't close to being compliant with the POSIX standard are 5822347Spst no longer supported. 5922347Spst 6022347Spst* Transition mechanisms are optional to prevent potential back doors. 6122347Spst 6222347Spst* On systems using the /etc/opieaccess transition mechanism, users can choose 6322347Spst to require the use of OPIE to login to their accounts when it would 6422347Spst otherwise be optional. 6522347Spst 6622347Spst* Bug fixes 6722347Spst 6822347Spst* Cosmetic changes 6922347Spst 7022347Spst* Prompts (optionally) identify specifically what kind of entry (system 7122347Spst password, secret pass phrase, or OTP response) is allowed. 7222347Spst 7322347Spst* Changes to mostly conform with the draft Internet OTP standard. 7422347Spst 7522347SpstA Glance at What's New 7622347Spst====================== 7722347Spst 7822347Spst 2.3 September 22, 1996 7922347Spst 8022347Spst Autoconf is now the only supported configuration method. 8122347Spst 8222347Spst Lots of internal functions got re-written in ways that will make some 8322347Spstplanned future changes easier. 8422347Spst 8522347Spst OTP extended responses, such as automatic re-initialization. 8622347Spst 8722347Spst Support for a supplemental key file that stores information that was 8822347Spstnot in the original /etc/skeykeys file. This allows OPIE to store extra data 8922347Spstneeded for things like the OTP re-initialization extended response without 9022347Spstbreaking interoperability with other S/Key derived programs. This file is 9122347Spstnamed "/etc/opiekeys.ext" by default. Unlike the standard key file, it MUST 9222347SpstNOT be world readable. 9322347Spst 9422347Spst OPIE should better support some of the native "features" of drain 9522347Spstbamaged OSs such as AIX, HP-UX, and Solaris. 9622347Spst 9722347Spst OPIE's utmp/wtmp handling has been completely re-written. This should 9822347Spstsolve many of the utmp/wtmp problems people have been having. 9922347Spst 10022347Spst Lots of cleanups. 10122347Spst 10222347Spst Bug fixes. 10322347Spst 10422347Spst 2.22 May 3, 1996. 10522347Spst 10622347Spst More minor bug fixes. OPIE once again works on Solaris 2.x. 10722347Spst 10822347Spst 2.21 April 27, 1996. 10922347Spst 11022347Spst Minor bug fixes. 11122347Spst 11222347Spst 2.2 April 11, 1996. 11322347Spst 11422347Spst opiesubr.c, opiesubr2.c, and a few other functions moved into 11522347Spsta subdirectory and split into files with fine granularity. Ditto with 11622347Spstmissing function replacements. This subdirectory structure changes a lot 11722347Spstof things around and more splitting like this should be expected in the 11822347Spstnear future. 11922347Spst 12022347Spst Added opiegenerator() library function that should make it very easy 12122347Spstto create OTP clients using the OPIE library (this function is subject to 12222347Spstchange: there are a few problems remaining to be solved). Just about re-write 12322347Spstopiegetpass() to use raw I/O and got most of the OPIE programs actually using 12422347Spstthat function. Autoconf build fixes. Lots of bug fixes. Lots of portability 12522347Spstfixes. Function declarations should be ANSI style for ANSI compilers. Several 12622347Spstfixes to bring OPIE in line with the latest OTP spec. MJR DES key crunch 12722347Spstde-implemented. 12822347Spst 12922347Spst Added sample programs: opiegen (client) and opieserv (server). 13022347Spst 13122347Spst Probably broke non-autoconf support along the way :(. I've tried to 13222347Spstbring this back in sync, but it may still be broken. 13322347Spst 13422347Spst 2.11 December 27, 1995. 13522347Spst 13622347Spst Minor bug fixes. 13722347Spst 13822347Spst 2.10 December 26, 1995. 13922347Spst 14022347Spst Optional autoconf support. opieinfo is now a normal program. 14122347SpstBugs fixed -- should work much better on SunOS, HP-UX, and AIX. 14222347Spst 14322347SpstSystem Requirements 14422347Spst=================== 14522347Spst 14622347Spst In order to build and run properly, OPIE requires: 14722347Spst 14822347Spst * A UNIX-like operating system 14922347Spst * An ANSI C compiler and run-time library 15022347Spst * POSIX.1- and X/Open XPG-compliance (including termios) 15122347Spst * The BSD sockets API 15222347Spst * Approximately five megabytes of free disk space 15322347Spst 15422347Spst In practice, we believe that many systems who are close to meeting 15522347Spstthese requirements but aren't completely there (for example, SunOS with the 15622347Spstnative compiler) will also work. Systems who aren't anywhere near close 15722347Spst(for example, DOS) are not likely to work without major adjustments to the 15822347SpstOPIE code. 15922347Spst 16022347SpstIf OPIE Doesn't Work 16122347Spst==================== 16222347Spst 16322347Spst First and foremost, make sure you have the latest version of OPIE. The 16422347Spstlatest version is available by anonymous FTP at: 16522347Spst 16622347Spst ftp://ftp.nrl.navy.mil/pub/security/opie 16722347Spst and 16822347Spst ftp://ftp.inner.net/pub/opie 16922347Spst 17022347Spst If you have installed the OPIE software (either through "make test" 17122347Spstin (7) above or "make install" in (14)), you can run "make uninstall" from the 17222347SpstOPIE software distribution directory. This should remove the OPIE software and 17322347Spstrestore the original system programs, but it will not work properly (and can 17422347Spsteven result in the total loss of the old system programs -- beware!) if the 17522347Spstinstallation procedure itself did not work properly. 17622347Spst 17722347Spst OPIE is NOT supported software. We don't promise to support you or 17822347Spsteven to acknowledge your mail, but we are interested in bug reports and are 17922347Spstreasonable folks. We also have an interest in seeing OPIE work on as many 18022347Spstsystems as we can. However, if your system doesn't meet the basic requirements 18122347Spstfor OPIE, this will probably require an unreasonable amount of effort. 18222347Spst 18322347Spst The best bug reports include a diagnosis of the problem and a fix. 18422347SpstYour bug report can still be valuable if you can at least diagnose what the 18522347Spstproblem is. If you just tell us "it doesn't work," then we won't be able to 18622347Spstdo anything to help you. 18722347Spst 18822347Spst We've received a number of bug reports from people that look 18922347Spstinteresting, only to find when we try to follow up on them that the user 19022347Spsteither has an invalid return address or never bothered to respond to our 19122347Spstfollowup. Please make sure that bug reports you send us have an electronic 19222347Spstmail address that we can reply to somewhere in them (if necessary, just 19322347Spstput it in the message body). If we send you a response and you are unable 19422347Spstto invest the time to work with us to solve the problem, please tell us -- 19522347Spstfew things are more irritating than when someone sends us information 19622347Spstabout a bug that we'd like to fix and then is never heard from again. 19722347Spst 19822347Spst We try to respond to all properly submitted bug reports. Improperly 19922347Spstsubmitted bug reports will be responded to only if we have time left after 20022347Spstresponding to properly submitted bug reports. We deliberately ignore bug 20122347Spst"reports" sent to mailing lists or USENET news groups instead of or before 20222347Spstour bug report address. At the least, the latter practice is lacking in 20322347Spstcourtesy. 20422347Spst 20522347Spst The file BUG-REPORT contains our bug reporting form. Please use it 20622347Spstand follow the submission instructions in that file. We are going to switch 20722347Spstto machine-parsed bug report processing sometime in the near future to make 20822347Spstit easier to coordinate bug hunting. 20922347Spst 21022347SpstGotchas 21122347Spst======= 21222347Spst 21322347Spst While an almost universal "feature", most people remain unaware that 21422347Spstan intruder can log into a system, then log in again by running the "login" 21522347Spstcommand from a shell. Because the second login is from the local host, the 21622347Spstutmp entry will not show a remote login host anymore. The OPIE replacement 21722347Spstfor /bin/login currently carries on this behavior for compatibility reasons. 21822347SpstIf you would like to prevent this from happening, you should change the 21922347Spstpermissions of /bin/login to 0100, thus preventing unprivileged users from 22022347Spstexecuting it. This fix should work on non-OPIE /bin/login programs as well. 22122347Spst 22222347Spst On 4.3BSDish systems, the supplied /bin/login replacement obtains 22322347Spstthe terminal type for the console comes from the console line in the /etc/ttys 22422347Spstfile. Several systems contain a default entry in this file that specifies the 22522347Spstconsole terminal type as "unknown". This is probably not what you want. 22622347Spst 22722347Spst The OPIE FTP daemon responds with two 530 error messages if you have 22822347Spstnot yet logged in and execute a command that will also do a PORT request. This 22922347Spstis a feature, not a bug, as the FTP client is really sending the server two 23022347Spstcommands (for instance, a PORT and a LIST if you tell your BSD FTP client to do 23122347Spsta DIR command) and the server is responding to each of them with an error. The 23222347Spststock BSD FTP daemon doesn't check the PORT commands to see if you are logged 23322347Spstin, so you would only get one error message. This change should not break any 23422347Spststandards-compliant FTP client, but there are a number of brain-damaged GUI 23522347Spstclients that have a track record for not dealing gracefully with any server 23622347Spstother than the stock BSD one. 23722347Spst 23822347Spst The /etc/opieaccess transition mechanism is, by definition, a security 23922347Spsthole in the OPIE software because an attacker could use it to circumvent the 24022347Spstrequirement for OPIE authentication. You should compile the software with 24122347Spstsupport for this file disabled unless you absolutely cannot use the software 24222347Spstwithout it because of your environment. If you do use this support for 24322347Spsttransition purposes, you should move people to OTP authentication as quickly 24422347Spstas possible and rebuild and reinstall OPIE with this transition support 24522347Spstdisabled so that you won't have a lurking security hole. 24622347Spst 24722347Spst If this wasn't already clear, do not let your sequence number fall 24822347Spstbelow about ten. If your sequence number reaches zero, your OTP sequence 24922347Spstcan only be reset by the superuser. System administrators should make this 25022347Spstcaveat known to their users. 25122347Spst 25222347Spst On Solaris 2.x systems (and possibly others) running NIS+, users 25322347Spstshould run keylogin(1) manually after login because opielogin(1) does not 25422347Spstdo that automatically like the system login(1) program. 25522347Spst 25622347Spst There are reports that some versions of GNU C Compiler (GCC) 25722347Spst(when installed on some systems) use their own termios(4) instead of 25822347Spstthe system's termios(4). This can cause problems. If you are having 25922347Spstcompilation problems that seem to relate to termios and you are using 26022347SpstGCC, you should probably verify that it is using the system's 26122347Spsttermios(4) and not some internal-to-GCC termios(4). One report 26222347Spstindicates that Sun's C compiler works fine with SunOS 4.1.3/4.1.4 on 26322347SpstSPARC, but that some version of GCC on the same system has this 26422347Spsttermios(4) problem. We haven't reproduced these problems ourselves 26522347Spstand hence aren't sure what is happening, but we pass this along for 26622347Spstyour information. (This may have something to do with the use of GNU 26722347Spstlibc) 26822347Spst 26922347Spst If a user has a valid entry in the opiekeys database but has an 27022347Spstasterisk in their traditional password entry, they will not be able to 27122347Spstlog in via opielogin, but opielogin will decrement their sequence number 27222347Spstif a valid response is received. 27322347Spst 27422347Spst On some systems, the OPIE login program does not always display 27522347Spsta "login:" prompt the first time. We think that this has something to do 27622347Spstwith the telnet daemon on those systems. (This is common on SunOS) You should 27722347Spstbe able to fix this by upgrading to the latest version of telnetd. 27822347Spst 27922347Spst The standard HPUX compiler is severely drain bamaged. One of the 28022347Spstworst parts is that it sometimes won't grok a symbol definition with forward 28122347Spstslashes in them properly and can choke badly on the definition of the key 28222347Spstfile's location. If this happens to you, install and use GCC. (This problem 28322347Spstmay or may not also come up with the optional HP ANSI C compiler -- we don't 28422347Spstknow for sure what compilers have this problem). 28522347Spst 28622347Spst As of OPIE 2.2, the seed is converted to lower case and its length is 28722347Spstchecked in order to comply with the OTP specification. If any of your users 28822347Spsthave seeds that use capital letters or are too long, they need to run the OPIE 28922347Spst2.2 opiepasswd program to re-initialize their sequence to one with a different 29022347Spstseed. 29122347Spst 29222347Spst opielogin is a replacement for /bin/login. It is NOT an OPIE "shell." 29322347SpstYou can use it as one, but don't be surprised if it doesn't behave the way 29422347Spstyou expect. An OPIE "shell" is on the TODO list. 29522347Spst 29622347Spst Clients that use opiegen() will automatically send a re-initialization 29722347Spstextended response if the sequence number falls below ten. If the server does 29822347Spstnot support this, the user will need to log in using opiekey and reset his 29922347Spstsequence manually (using opiepasswd). 30022347Spst 30122347SpstGripes 30222347Spst====== 30322347Spst 30422347Spst Is it too much to ask that certain OS vendors just do the right thing 30522347Spstand not fix what isn't broken? (Look at all the ifdefs in the OPIE code and 30622347Spstthe answer is clear) 30722347Spst 30822347SpstCredits 30922347Spst======= 31022347Spst 31122347Spst First and foremost credit goes to Phil Karn, Neil M. Haller, and John 31222347SpstS. Walden of Bellcore for creating the S/Key Version 1 software distribution 31322347Spstand for making its source code freely available to the public. Without their 31422347Spstwork, OPIE would not exist. Neil has also invested a good amount of his time 31522347Spstin the development of a standard for One-Time Passwords so that packages like 31622347SpstOPIE can interoperate. 31722347Spst 31822347Spst The first NRL OPIE distribution included modifications made primarily 31922347Spstby Dan McDonald of the U.S. Naval Research Laboratory (NRL) during March 1994. 32022347SpstThe 2nd NRL OPIE distribution, which has a number of improvements in areas 32122347Spstsuch as portability of software and ease of installation, is primarily the 32222347Spstwork of Ran Atkinson and Craig Metz. Other NRL contributors include Brian 32322347SpstAdamson, Steve Batsell, Preston Mullen, Bao Phan, Jim Ramsey, and Georg Thomas. 32422347Spst 32522347Spst Some of version 2.2 was developed at NRL and released as a work in 32622347Spstprogress. Most of the release version was developed by Craig Metz (also of 32722347SpstNRL), others at The Inner Net, and contributors from the Internet community. 32822347SpstVersions beyond 2.2 were developed outside NRL, so don't blame them if they 32922347Spstdon't work (But please credit them when it does. Without the NRL effort, there 33022347Spstwouldn't be an OPIE). 33122347Spst 33222347Spst We would like to also thank everyone who helped us by by beta testing, 33322347Spstreporting bugs, suggesting improvements, and/or sending us patches. We 33422347Spstappreciate your contributions -- they have helped to make OPIE more of a 33522347Spstcommunity effort. These contributors include: 33622347Spst 33722347Spst Mowgli Assor 33822347Spst Lawrie Brown 33922347Spst Axel Grewe 34022347Spst "Hobbit" 34122347Spst Darren Hosking 34222347Spst Martijn Koster 34322347Spst Osamu Kurati 34422347Spst Ayamura Kikuchi 34522347Spst Ikuo Nakagawa 34622347Spst Angelo Neri 34722347Spst D. Jason Penney 34822347Spst John Perkins 34922347Spst Jim Simmons 35022347Spst Werner Wiethege 35122347Spst Wietse Venema 35222347Spst 35322347Spst OPIE development at NRL was sponsored by the Information Security 35422347SpstProgram Office (PD 71E), U.S. Space and Naval Warfare Systems Command, Crystal 35522347SpstCity, Virginia. 35622347Spst 35722347Spst If you have problems with OPIE, please follow the instructions under 35822347Spst"If OPIE Doesn't Work." Under NO circumstances should you send trouble 35922347Spstreports directly to the authors or contributors. 36022347Spst 36122347SpstTrademarks 36222347Spst========== 36322347SpstS/Key is a trademark of Bell Communications Research (Bellcore). 36422347SpstUNIX is a trademark of X/Open. 36522347SpstNRL is a trademark of the U. S. Naval Research Laboratory. 36622347Spst 36722347SpstAll other trademarks are trademarks of their respective owners. 36822347Spst 36922347SpstThe term "OPIE" is in the public domain and hence cannot be legally 37022347Spsttrademarked by anyone. 37122347Spst 37222347SpstCopyrights 37322347Spst========== 37422347Spst%%% portions-copyright-cmetz 37522347SpstPortions of this software are Copyright 1996 by Craig Metz, All Rights 37622347SpstReserved. The Inner Net License Version 2 applies to these portions of 37722347Spstthe software. 37822347SpstYou should have received a copy of the license with this software. If 37922347Spstyou didn't get a copy, you may request one from <license@inner.net>. 38022347Spst 38122347SpstPortions of this software are Copyright 1995 by Randall Atkinson and Dan 38222347SpstMcDonald, All Rights Reserved. All Rights under this copyright are assigned 38322347Spstto the U.S. Naval Research Laboratory (NRL). The NRL Copyright Notice and 38422347SpstLicense Agreement applies to this software. 38522347Spst 38622347SpstPortions of this software are copyright 1980-1990 Regents of the 38722347SpstUniversity of California, all rights reserved. The Berkeley Software 38822347SpstLicense Agreement specifies the terms and conditions for redistribution. 38922347Spst 39022347SpstPortions of this software are copyright 1990 Bell Communications Research 39122347Spst(Bellcore), all rights reserved. 392