OpenSSL Example Programs 20020110by Eric RescorlaJanuary 10, 2002 EditionCopyright (C) 2001 RTFM, Inc.INTRODUCTIONThis is a set of example programs demonstrating how to performbasic tasks with OpenSSL. There are five programs:wclient	    -- a simple web client emulatorwserver	    -- a simple web server emulatorwclient2    -- a version of wclient with some extra options	       including setting the cipher suite and 	       session caching.wserver2    -- a version of wserver2 with some extra options	       including setting the cipher suite, client	       authentication, rehandshake, and session caching.sclient	    -- a simple client program that echos from the keyboard	       to the server and vice versa. sclient is a simple	       model of a terminal client such as Telnet.See the file RUNNING for documentation on the command lineswitches for these programs.DOCUMENTATIONAlthough the programs are extensively commented they are notcompletely self-explanatory. Rather, they are intended to be used as acompanion to a series of articles published in Linux Journal. Thefirst article was published in the September issue and is includedhere as part1.pdf. The second article was published on the webin early October and is included here as part2.pdfThis explains why we have both wclient and wclient2 (and wserver andwserver2). The first editions appear in the first article and thesecond ones in the second article. This structure also lets thereader learn the basics without advanced features getting in theway.BUILDINGThese programs are designed to build with GNU autoconf. With any luck you can build simply by doing	./configure	makeIf the configure script can't find OpenSSL, it will exit with anerror. If your OpenSSL is in a nonstandard location, you will need togive configure a hint with the '--with-openssl' or'--with-openssl-{lib,include}' switches.If you have some problem building this software, please senda bug report to <ekr@rtfm.com>.LICENSECopyright (C) 2000-2001 RTFM, Inc.All Rights ReservedThis package is a series of demonstration programs written byEric Rescorla <ekr@rtfm.com> and licensed by RTFM, Inc.Redistribution and use in source and binary forms, with or withoutmodification, are permitted provided that the following conditionsare met:1. Redistributions of source code must retain the above copyright   notice, this list of conditions and the following disclaimer.2. Redistributions in binary form must reproduce the above copyright   notice, this list of conditions and the following disclaimer in the   documentation and/or other materials provided with the distribution.3. Neither the name of RTFM, Inc. nor the name of Eric Rescorla may be   used to endorse or promote products derived from this   software without specific prior written permission.THIS SOFTWARE IS PROVIDED BY THE ERIC RESCORLA AND RTFM ``AS IS'' ANDANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THEIMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSEARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLEFOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIALDAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODSOR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICTLIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAYOUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OFSUCH DAMAGE.SHAMELESS PLUGExtremely detailed coverage of SSL/TLS can be found in 	_SSL_and_TLS:_Designing_and_Building_Secure_Systems_	Eric Rescorla	Addison-Wesley, 2001	ISBN 0-201-61598-3The original versions of these programs appeared in that book.