openssl

OpenSSL 1.1.0-dev

Copyright (c) 1998-2011 The OpenSSL Project
Copyright (c) 1995-1998 Eric A. Young, Tim J. Hudson
All rights reserved.

DESCRIPTION
-----------

The OpenSSL Project is a collaborative effort to develop a robust,
commercial-grade, fully featured, and Open Source toolkit implementing the
Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1)
protocols as well as a full-strength general purpose cryptography library.
The project is managed by a worldwide community of volunteers that use the
Internet to communicate, plan, and develop the OpenSSL toolkit and its
related documentation.

OpenSSL is based on the excellent SSLeay library developed from Eric A. Young
and Tim J. Hudson. The OpenSSL toolkit is licensed under a dual-license (the
OpenSSL license plus the SSLeay license) situation, which basically means
that you are free to get and use it for commercial and non-commercial
purposes as long as you fulfill the conditions of both licenses.

OVERVIEW
--------

The OpenSSL toolkit includes:

libssl.a:
Implementation of SSLv2, SSLv3, TLSv1 and the required code to support
both SSLv2, SSLv3 and TLSv1 in the one server and client.

libcrypto.a:
General encryption and X.509 v1/v3 stuff needed by SSL/TLS but not
actually logically part of it. It includes routines for the following:

Ciphers
libdes - EAY's libdes DES encryption package which was floating
around the net for a few years, and was then relicensed by
him as part of SSLeay. It includes 15 'modes/variations'
of DES (1, 2 and 3 key versions of ecb, cbc, cfb and ofb;
pcbc and a more general form of cfb and ofb) including desx
in cbc mode, a fast crypt(3), and routines to read
passwords from the keyboard.
RC4 encryption,
RC2 encryption - 4 different modes, ecb, cbc, cfb and ofb.
Blowfish encryption - 4 different modes, ecb, cbc, cfb and ofb.
IDEA encryption - 4 different modes, ecb, cbc, cfb and ofb.

Digests
MD5 and MD2 message digest algorithms, fast implementations,
SHA (SHA-0) and SHA-1 message digest algorithms,
MDC2 message digest. A DES based hash that is popular on smart cards.

Public Key
RSA encryption/decryption/generation.
There is no limit on the number of bits.
DSA encryption/decryption/generation.
There is no limit on the number of bits.
Diffie-Hellman key-exchange/key generation.
There is no limit on the number of bits.

X.509v3 certificates
X509 encoding/decoding into/from binary ASN1 and a PEM
based ASCII-binary encoding which supports encryption with a
private key. Program to generate RSA and DSA certificate
requests and to generate RSA and DSA certificates.

Systems
The normal digital envelope routines and base64 encoding. Higher
level access to ciphers and digests by name. New ciphers can be
loaded at run time. The BIO io system which is a simple non-blocking
IO abstraction. Current methods supported are file descriptors,
sockets, socket accept, socket connect, memory buffer, buffering, SSL
client/server, file pointer, encryption, digest, non-blocking testing
and null.

Data structures
A dynamically growing hashing system
A simple stack.
A Configuration loader that uses a format similar to MS .ini files.

openssl:
A command line tool that can be used for:
Creation of RSA, DH and DSA key parameters
Creation of X.509 certificates, CSRs and CRLs
Calculation of Message Digests
Encryption and Decryption with Ciphers
SSL/TLS Client and Server Tests
Handling of S/MIME signed or encrypted mail

INSTALLATION
------------

To install this package under a Unix derivative, read the INSTALL file. For
a Win32 platform, read the INSTALL.W32 file. For OpenVMS systems, read
INSTALL.VMS.

Read the documentation in the doc/ directory. It is quite rough, but it
lists the functions; you will probably have to look at the code to work out
how to use them. Look at the example programs.

PROBLEMS
--------

For some platforms, there are some known problems that may affect the user
or application author. We try to collect those in doc/PROBLEMS, with current
thoughts on how they should be solved in a future of OpenSSL.

SUPPORT
-------

See the OpenSSL website www.openssl.org for details of how to obtain
commercial technical support.

If you have any problems with OpenSSL then please take the following steps
first:

- Download the current snapshot from ftp://ftp.openssl.org/snapshot/
to see if the problem has already been addressed
- Remove ASM versions of libraries
- Remove compiler optimisation flags

If you wish to report a bug then please include the following information in
any bug report:

- On Unix systems:
Self-test report generated by 'make report'
- On other systems:
OpenSSL version: output of 'openssl version -a'
OS Name, Version, Hardware platform
Compiler Details (name, version)
- Application Details (name, version)
- Problem Description (steps that will reproduce the problem, if known)
- Stack Traceback (if the application dumps core)

Email the report to:

openssl-bugs@openssl.org

Note that the request tracker should NOT be used for general assistance
or support queries. Just because something doesn't work the way you expect
does not mean it is necessarily a bug in OpenSSL.

Note that mail to openssl-bugs@openssl.org is recorded in the public
request tracker database (see https://www.openssl.org/support/rt.html
for details) and also forwarded to a public mailing list. Confidential
mail may be sent to openssl-security@openssl.org (PGP key available from
the key servers).

HOW TO CONTRIBUTE TO OpenSSL
----------------------------

Development is coordinated on the openssl-dev mailing list (see
http://www.openssl.org for information on subscribing). If you
would like to submit a patch, send it to openssl-bugs@openssl.org with
the string "[PATCH]" in the subject. Please be sure to include a
textual explanation of what your patch does.

If you are unsure as to whether a feature will be useful for the general
OpenSSL community please discuss it on the openssl-dev mailing list first.
Someone may be already working on the same thing or there may be a good
reason as to why that feature isn't implemented.

Patches should be as up to date as possible, preferably relative to the
current Git or the last snapshot. They should follow the coding style of
OpenSSL and compile without warnings. Some of the core team developer targets
can be used for testing purposes, (debug-steve64, debug-geoff etc). OpenSSL
compiles on many varied platforms: try to ensure you only use portable
features.

Note: For legal reasons, contributions from the US can be accepted only
if a TSU notification and a copy of the patch are sent to crypt@bis.doc.gov
(formerly BXA) with a copy to the ENC Encryption Request Coordinator;
please take some time to look at
http://www.bis.doc.gov/Encryption/PubAvailEncSourceCodeNofify.html [sic]
and
http://w3.access.gpo.gov/bis/ear/pdf/740.pdf (EAR Section 740.13(e))
for the details. If "your encryption source code is too large to serve as
an email attachment", they are glad to receive it by fax instead; hope you
have a cheap long-distance plan.

Our preferred format for changes is "diff -u" output. You might
generate it like this:

# cd openssl-work
# [your changes]
# ./Configure dist; make clean
# cd ..
# diff -ur openssl-orig openssl-work > mydiffs.patch