1 2 OpenSSL 0.9.8zh 3 Dec 2015 3 4 Copyright (c) 1998-2011 The OpenSSL Project 5 Copyright (c) 1995-1998 Eric A. Young, Tim J. Hudson 6 All rights reserved. 7 8 DESCRIPTION 9 ----------- 10 11 The OpenSSL Project is a collaborative effort to develop a robust, 12 commercial-grade, fully featured, and Open Source toolkit implementing the 13 Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) 14 protocols as well as a full-strength general purpose cryptography library. 15 The project is managed by a worldwide community of volunteers that use the 16 Internet to communicate, plan, and develop the OpenSSL toolkit and its 17 related documentation. 18 19 OpenSSL is based on the excellent SSLeay library developed from Eric A. Young 20 and Tim J. Hudson. The OpenSSL toolkit is licensed under a dual-license (the 21 OpenSSL license plus the SSLeay license) situation, which basically means 22 that you are free to get and use it for commercial and non-commercial 23 purposes as long as you fulfill the conditions of both licenses. 24 25 OVERVIEW 26 -------- 27 28 The OpenSSL toolkit includes: 29 30 libssl.a: 31 Implementation of SSLv2, SSLv3, TLSv1 and the required code to support 32 both SSLv2, SSLv3 and TLSv1 in the one server and client. 33 34 libcrypto.a: 35 General encryption and X.509 v1/v3 stuff needed by SSL/TLS but not 36 actually logically part of it. It includes routines for the following: 37 38 Ciphers 39 libdes - EAY's libdes DES encryption package which was floating 40 around the net for a few years, and was then relicensed by 41 him as part of SSLeay. It includes 15 'modes/variations' 42 of DES (1, 2 and 3 key versions of ecb, cbc, cfb and ofb; 43 pcbc and a more general form of cfb and ofb) including desx 44 in cbc mode, a fast crypt(3), and routines to read 45 passwords from the keyboard. 46 RC4 encryption, 47 RC2 encryption - 4 different modes, ecb, cbc, cfb and ofb. 48 Blowfish encryption - 4 different modes, ecb, cbc, cfb and ofb. 49 IDEA encryption - 4 different modes, ecb, cbc, cfb and ofb. 50 51 Digests 52 MD5 and MD2 message digest algorithms, fast implementations, 53 SHA (SHA-0) and SHA-1 message digest algorithms, 54 MDC2 message digest. A DES based hash that is popular on smart cards. 55 56 Public Key 57 RSA encryption/decryption/generation. 58 There is no limit on the number of bits. 59 DSA encryption/decryption/generation. 60 There is no limit on the number of bits. 61 Diffie-Hellman key-exchange/key generation. 62 There is no limit on the number of bits. 63 64 X.509v3 certificates 65 X509 encoding/decoding into/from binary ASN1 and a PEM 66 based ASCII-binary encoding which supports encryption with a 67 private key. Program to generate RSA and DSA certificate 68 requests and to generate RSA and DSA certificates. 69 70 Systems 71 The normal digital envelope routines and base64 encoding. Higher 72 level access to ciphers and digests by name. New ciphers can be 73 loaded at run time. The BIO io system which is a simple non-blocking 74 IO abstraction. Current methods supported are file descriptors, 75 sockets, socket accept, socket connect, memory buffer, buffering, SSL 76 client/server, file pointer, encryption, digest, non-blocking testing 77 and null. 78 79 Data structures 80 A dynamically growing hashing system 81 A simple stack. 82 A Configuration loader that uses a format similar to MS .ini files. 83 84 openssl: 85 A command line tool that can be used for: 86 Creation of RSA, DH and DSA key parameters 87 Creation of X.509 certificates, CSRs and CRLs 88 Calculation of Message Digests 89 Encryption and Decryption with Ciphers 90 SSL/TLS Client and Server Tests 91 Handling of S/MIME signed or encrypted mail 92 93 94 PATENTS 95 ------- 96 97 Various companies hold various patents for various algorithms in various 98 locations around the world. _YOU_ are responsible for ensuring that your use 99 of any algorithms is legal by checking if there are any patents in your 100 country. The file contains some of the patents that we know about or are 101 rumored to exist. This is not a definitive list. 102 103 RSA Security holds software patents on the RC5 algorithm. If you 104 intend to use this cipher, you must contact RSA Security for 105 licensing conditions. Their web page is http://www.rsasecurity.com/. 106 107 RC4 is a trademark of RSA Security, so use of this label should perhaps 108 only be used with RSA Security's permission. 109 110 The IDEA algorithm is patented by Ascom in Austria, France, Germany, Italy, 111 Japan, the Netherlands, Spain, Sweden, Switzerland, UK and the USA. They 112 should be contacted if that algorithm is to be used; their web page is 113 http://www.ascom.ch/. 114 115 NTT and Mitsubishi have patents and pending patents on the Camellia 116 algorithm, but allow use at no charge without requiring an explicit 117 licensing agreement: http://info.isl.ntt.co.jp/crypt/eng/info/chiteki.html 118 119 INSTALLATION 120 ------------ 121 122 To install this package under a Unix derivative, read the INSTALL file. For 123 a Win32 platform, read the INSTALL.W32 file. For OpenVMS systems, read 124 INSTALL.VMS. 125 126 Read the documentation in the doc/ directory. It is quite rough, but it 127 lists the functions; you will probably have to look at the code to work out 128 how to use them. Look at the example programs. 129 130 PROBLEMS 131 -------- 132 133 For some platforms, there are some known problems that may affect the user 134 or application author. We try to collect those in doc/PROBLEMS, with current 135 thoughts on how they should be solved in a future of OpenSSL. 136 137 SUPPORT 138 ------- 139 140 See the OpenSSL website www.openssl.org for details of how to obtain 141 commercial technical support. 142 143 If you have any problems with OpenSSL then please take the following steps 144 first: 145 146 - Download the current snapshot from ftp://ftp.openssl.org/snapshot/ 147 to see if the problem has already been addressed 148 - Remove ASM versions of libraries 149 - Remove compiler optimisation flags 150 151 If you wish to report a bug then please include the following information in 152 any bug report: 153 154 - On Unix systems: 155 Self-test report generated by 'make report' 156 - On other systems: 157 OpenSSL version: output of 'openssl version -a' 158 OS Name, Version, Hardware platform 159 Compiler Details (name, version) 160 - Application Details (name, version) 161 - Problem Description (steps that will reproduce the problem, if known) 162 - Stack Traceback (if the application dumps core) 163 164 Report the bug to the OpenSSL project via the Request Tracker 165 (http://www.openssl.org/support/rt.html) by mail to: 166 167 rt@openssl.org 168 169 In order to avoid spam, this is a moderated mailing list, and it might 170 take a day for the ticket to show up. (We also scan posts to make sure 171 that security disclosures aren't publically posted by mistake.) Mail to 172 this address is recorded in the public RT (request tracker) database (see 173 https://www.openssl.org/support/rt.html for details) and also forwarded 174 the public openssl-dev mailing list. Confidential mail may be sent to 175 openssl-security@openssl.org (PGP key available from the key servers). 176 177 Please do NOT use this for general assistance or support queries. 178 Just because something doesn't work the way you expect does not mean it 179 is necessarily a bug in OpenSSL. 180 181 You can also make GitHub pull requests. If you do this, please also send 182 mail to rt@openssl.org with a link to the PR so that we can more easily 183 keep track of it. 184 185 HOW TO CONTRIBUTE TO OpenSSL 186 ---------------------------- 187 188 Development is coordinated on the openssl-dev mailing list (see 189 http://www.openssl.org for information on subscribing). If you 190 would like to submit a patch, send it to openssl-bugs@openssl.org with 191 the string "[PATCH]" in the subject. Please be sure to include a 192 textual explanation of what your patch does. 193 194 If you are unsure as to whether a feature will be useful for the general 195 OpenSSL community please discuss it on the openssl-dev mailing list first. 196 Someone may be already working on the same thing or there may be a good 197 reason as to why that feature isn't implemented. 198 199 Patches should be as up to date as possible, preferably relative to the 200 current Git or the last snapshot. They should follow our coding style 201 (see http://openssl.org/about/codingstyle.txt) and compile without 202 warnings using the --strict-warnings flag. OpenSSL compiles on many 203 varied platforms: try to ensure you only use portable features. 204 205 Note: For legal reasons, contributions from the US can be accepted only 206 if a TSU notification and a copy of the patch are sent to crypt@bis.doc.gov 207 (formerly BXA) with a copy to the ENC Encryption Request Coordinator; 208 please take some time to look at 209 http://www.bis.doc.gov/Encryption/PubAvailEncSourceCodeNofify.html [sic] 210 and 211 http://w3.access.gpo.gov/bis/ear/pdf/740.pdf (EAR Section 740.13(e)) 212 for the details. If "your encryption source code is too large to serve as 213 an email attachment", they are glad to receive it by fax instead; hope you 214 have a cheap long-distance plan. 215 216 Our preferred format for changes is "diff -u" output. You might 217 generate it like this: 218 219 # cd openssl-work 220 # [your changes] 221 # ./Configure dist; make clean 222 # cd .. 223 # diff -ur openssl-orig openssl-work > mydiffs.patch 224 225