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openssl Cross Reference



0002  OpenSSL 1.0.1h 5 Jun 2014
0004  Copyright (c) 1998-2011 The OpenSSL Project
0005  Copyright (c) 1995-1998 Eric A. Young, Tim J. Hudson
0006  All rights reserved.
0009  -----------
0011  The OpenSSL Project is a collaborative effort to develop a robust,
0012  commercial-grade, fully featured, and Open Source toolkit implementing the
0013  Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1)
0014  protocols as well as a full-strength general purpose cryptography library.
0015  The project is managed by a worldwide community of volunteers that use the
0016  Internet to communicate, plan, and develop the OpenSSL toolkit and its
0017  related documentation.
0019  OpenSSL is based on the excellent SSLeay library developed from Eric A. Young
0020  and Tim J. Hudson.  The OpenSSL toolkit is licensed under a dual-license (the
0021  OpenSSL license plus the SSLeay license) situation, which basically means
0022  that you are free to get and use it for commercial and non-commercial
0023  purposes as long as you fulfill the conditions of both licenses.
0026  --------
0028  The OpenSSL toolkit includes:
0030  libssl.a:
0031      Implementation of SSLv2, SSLv3, TLSv1 and the required code to support
0032      both SSLv2, SSLv3 and TLSv1 in the one server and client.
0034  libcrypto.a:
0035      General encryption and X.509 v1/v3 stuff needed by SSL/TLS but not
0036      actually logically part of it. It includes routines for the following:
0038      Ciphers
0039         libdes - EAY's libdes DES encryption package which was floating
0040                  around the net for a few years, and was then relicensed by
0041                  him as part of SSLeay.  It includes 15 'modes/variations'
0042                  of DES (1, 2 and 3 key versions of ecb, cbc, cfb and ofb;
0043                  pcbc and a more general form of cfb and ofb) including desx
0044                  in cbc mode, a fast crypt(3), and routines to read
0045                  passwords from the keyboard.
0046         RC4 encryption,
0047         RC2 encryption      - 4 different modes, ecb, cbc, cfb and ofb.
0048         Blowfish encryption - 4 different modes, ecb, cbc, cfb and ofb.
0049         IDEA encryption     - 4 different modes, ecb, cbc, cfb and ofb.
0051      Digests
0052         MD5 and MD2 message digest algorithms, fast implementations,
0053         SHA (SHA-0) and SHA-1 message digest algorithms,
0054         MDC2 message digest. A DES based hash that is popular on smart cards.
0056      Public Key
0057         RSA encryption/decryption/generation.
0058             There is no limit on the number of bits.
0059         DSA encryption/decryption/generation.
0060             There is no limit on the number of bits.
0061         Diffie-Hellman key-exchange/key generation.
0062             There is no limit on the number of bits.
0064      X.509v3 certificates
0065         X509 encoding/decoding into/from binary ASN1 and a PEM
0066              based ASCII-binary encoding which supports encryption with a
0067              private key.  Program to generate RSA and DSA certificate
0068              requests and to generate RSA and DSA certificates.
0070      Systems
0071         The normal digital envelope routines and base64 encoding.  Higher
0072         level access to ciphers and digests by name.  New ciphers can be
0073         loaded at run time.  The BIO io system which is a simple non-blocking
0074         IO abstraction.  Current methods supported are file descriptors,
0075         sockets, socket accept, socket connect, memory buffer, buffering, SSL
0076         client/server, file pointer, encryption, digest, non-blocking testing
0077         and null.
0079      Data structures
0080         A dynamically growing hashing system
0081         A simple stack.
0082         A Configuration loader that uses a format similar to MS .ini files.
0084  openssl:
0085      A command line tool that can be used for:
0086         Creation of RSA, DH and DSA key parameters
0087         Creation of X.509 certificates, CSRs and CRLs
0088         Calculation of Message Digests
0089         Encryption and Decryption with Ciphers
0090         SSL/TLS Client and Server Tests
0091         Handling of S/MIME signed or encrypted mail
0095  -------
0097  Various companies hold various patents for various algorithms in various
0098  locations around the world. _YOU_ are responsible for ensuring that your use
0099  of any algorithms is legal by checking if there are any patents in your
0100  country.  The file contains some of the patents that we know about or are
0101  rumored to exist. This is not a definitive list.
0103  RSA Security holds software patents on the RC5 algorithm.  If you
0104  intend to use this cipher, you must contact RSA Security for
0105  licensing conditions. Their web page is
0107  RC4 is a trademark of RSA Security, so use of this label should perhaps
0108  only be used with RSA Security's permission.
0110  The IDEA algorithm is patented by Ascom in Austria, France, Germany, Italy,
0111  Japan, the Netherlands, Spain, Sweden, Switzerland, UK and the USA.  They
0112  should be contacted if that algorithm is to be used; their web page is
0115  NTT and Mitsubishi have patents and pending patents on the Camellia
0116  algorithm, but allow use at no charge without requiring an explicit
0117  licensing agreement:
0120  ------------
0122  To install this package under a Unix derivative, read the INSTALL file.  For
0123  a Win32 platform, read the INSTALL.W32 file.  For OpenVMS systems, read
0126  Read the documentation in the doc/ directory.  It is quite rough, but it
0127  lists the functions; you will probably have to look at the code to work out
0128  how to use them. Look at the example programs.
0131  --------
0133  For some platforms, there are some known problems that may affect the user
0134  or application author.  We try to collect those in doc/PROBLEMS, with current
0135  thoughts on how they should be solved in a future of OpenSSL.
0138  -------
0140  See the OpenSSL website for details of how to obtain
0141  commercial technical support.
0143  If you have any problems with OpenSSL then please take the following steps
0144  first:
0146     - Download the current snapshot from
0147       to see if the problem has already been addressed
0148     - Remove ASM versions of libraries
0149     - Remove compiler optimisation flags
0151  If you wish to report a bug then please include the following information in
0152  any bug report:
0154     - On Unix systems:
0155         Self-test report generated by 'make report'
0156     - On other systems:
0157         OpenSSL version: output of 'openssl version -a'
0158         OS Name, Version, Hardware platform
0159         Compiler Details (name, version)
0160     - Application Details (name, version)
0161     - Problem Description (steps that will reproduce the problem, if known)
0162     - Stack Traceback (if the application dumps core)
0164  Report the bug to the OpenSSL project via the Request Tracker
0165  ( by mail to:
0169  Note that the request tracker should NOT be used for general assistance
0170  or support queries. Just because something doesn't work the way you expect
0171  does not mean it is necessarily a bug in OpenSSL.
0173  Note that mail to is recorded in the publicly
0174  readable request tracker database and is forwarded to a public
0175  mailing list. Confidential mail may be sent to
0176  (PGP key available from the key servers).
0179  ----------------------------
0181  Development is coordinated on the openssl-dev mailing list (see
0182 for information on subscribing). If you
0183  would like to submit a patch, send it to with
0184  the string "[PATCH]" in the subject. Please be sure to include a
0185  textual explanation of what your patch does.
0187  If you are unsure as to whether a feature will be useful for the general
0188  OpenSSL community please discuss it on the openssl-dev mailing list first.
0189  Someone may be already working on the same thing or there may be a good
0190  reason as to why that feature isn't implemented.
0192  Patches should be as up to date as possible, preferably relative to the
0193  current Git or the last snapshot. They should follow the coding style of
0194  OpenSSL and compile without warnings. Some of the core team developer targets
0195  can be used for testing purposes, (debug-steve64, debug-geoff etc). OpenSSL
0196  compiles on many varied platforms: try to ensure you only use portable
0197  features.
0199  Note: For legal reasons, contributions from the US can be accepted only
0200  if a TSU notification and a copy of the patch are sent to
0201  (formerly BXA) with a copy to the ENC Encryption Request Coordinator;
0202  please take some time to look at
0203 [sic]
0204  and
0205 (EAR Section 740.13(e))
0206  for the details. If "your encryption source code is too large to serve as
0207  an email attachment", they are glad to receive it by fax instead; hope you
0208  have a cheap long-distance plan.
0210  Our preferred format for changes is "diff -u" output. You might
0211  generate it like this:
0213  # cd openssl-work
0214  # [your changes]
0215  # ./Configure dist; make clean
0216  # cd ..
0217  # diff -ur openssl-orig openssl-work > mydiffs.patch