X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=README;h=02c2cab585a57afc839c0881c8c41b3e34572058;hp=d368fc88f90b3369ae26134d396b0b8f68ab6c87;hb=3ca724e191958ea2ba63ef10eeef7eb51b5dd230;hpb=ee96ccabbbf0180d5631d3c22838456f28ee9c15 diff --git a/README b/README index d368fc88..02c2cab5 100644 --- a/README +++ b/README @@ -1,37 +1,124 @@ -This is the README file for tinc version 1.0. -Installation instructions may be found in the INSTALL file. +This is the README file for tinc version 1.0.34. Installation +instructions may be found in the INSTALL file. -tinc is Copyright (C) 1998,1999,2000 Ivo Timmermans and -others. For a complete list of authors see the AUTHORS file. -This product includes software developed by Eric Young (eay@mincom.oz.au) +tinc is Copyright (C) 1998-2018 by: + +Ivo Timmermans, +Guus Sliepen , +and others. + +For a complete list of authors see the AUTHORS file. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. See the file COPYING for more details. -This version of tinc relies on the GNU Multi-Precision Library -(gmp). This library is available from your nearest GNU mirror. Please -install this first even before trying to run configure. If you don't -do this, configure will (hopefully) mention it to you. + +Security statement +------------------ + +In August 2000, we discovered the existence of a security hole in all versions +of tinc up to and including 1.0pre2. This had to do with the way we exchanged +keys. Since then, we have been working on a new authentication scheme to make +tinc as secure as possible. The current version uses the OpenSSL library and +uses strong authentication with RSA keys. + +On the 29th of December 2001, Jerome Etienne posted a security analysis of tinc +1.0pre4. Due to a lack of sequence numbers and a message authentication code +for each packet, an attacker could possibly disrupt certain network services or +launch a denial of service attack by replaying intercepted packets. The current +version adds sequence numbers and message authentication codes to prevent such +attacks. + +On September the 15th of 2003, Peter Gutmann contacted us and showed us a +writeup describing various security issues in several VPN daemons. He showed +that tinc lacks perfect forward security, the connection authentication could +be done more properly, that the sequence number we use as an IV is not the best +practice and that the default length of the HMAC for packets is too short in +his opinion. We do not know of a way to exploit these weaknesses, but these +issues are being addressed in the tinc 1.1 branch. + +The Sweet32 attack affects versions of tinc prior to 1.0.30. + +Cryptography is a hard thing to get right. We cannot make any +guarantees. Time, review and feedback are the only things that can +prove the security of any cryptographic product. If you wish to review +tinc or give us feedback, you are strongly encouraged to do so. + + +Compatibility +------------- + +Version 1.0.31 is compatible with 1.0pre8, 1.0 and later, but not with older +versions of tinc. Note that since version 1.0.30, tinc requires all nodes in +the VPN to be compiled with a version of LibreSSL or OpenSSL that supports the +AES256 and SHA256 algorithms. + + +Requirements +------------ + +The OpenSSL library is used for all cryptographic functions. You can find it at +https://www.openssl.org/. You will need version 1.0.1 or later with support for +AES256 and SHA256 enabled. If this library is not installed on your system, the +configure script will fail. The manual in doc/tinc.texi contains more detailed +information on how to install this library. Alternatively, you may also use the +LibreSSL library. + +The zlib library is used for optional compression. You can +find it at https://zlib.net/. Because of a possible exploit in +earlier versions we recommend that you download version 1.1.4 or later. + +The LZO library is also used for optional compression. You can +find it at https://www.oberhumer.com/opensource/lzo/. + +In order to compile tinc, you will need a C99 compliant compiler. + + +Features +-------- This version of tinc supports multiple virtual networks at once. To use this feature, you may supply a netname via the -n or --net options. The standard locations for the config files will then be -/etc/tinc//. Because of this feature, tinc will send packets -directly to their destinations, instead of to the uplink. If this -behaviour is undesirable (for instance because of firewalls or -other restrictions), please use an older version of tinc (I would -recommend tinc-0.2.19). - -In this version, MAC addresses are stripped off before encoding and -sending a packet. When the packet reaches its destination, the MAC -addresses are rebuilt again. They then have the form -FE:FD:aa:bb:cc:dd. aa, bb, cc and dd are taken from the destination -and source IP address. +/etc/tinc//. tincd regenerates its encryption key pairs. It does this on the first activity after the keys have expired. This period is adjustable in the -configuration file, and the default time is 3600 seconds (one -hour). If you send a USR2 signal to the daemon, it'll regenerate -immediately. +configuration file, and the default time is 3600 seconds (one hour). + +This version supports multiple subnets at once. They are also sorted +on subnet mask size. This means that it is possible to have +overlapping subnets on the VPN, as long as their subnet mask sizes +differ. + +Since pre5, tinc can operate in several routing modes. The default mode, +"router", works exactly like the older version, and uses Subnet lines to +determine the destination of packets. The other two modes, "switch" and "hub", +allow the tinc daemons to work together like a single network switch or hub. +This is useful for bridging networks. The latter modes only work properly on +Linux, FreeBSD and Windows. + +The algorithms used for encryption and generating message authentication codes +can now be changed in the configuration files. All cipher and digest algorithms +supported by OpenSSL can be used. Useful ciphers are "blowfish" (default), +"bf-ofb", "des", "des3", et cetera. Useful digests are "sha1" (default), "md5", +et cetera. + +Support for routing IPv6 packets has been added. Just add Subnet lines with +IPv6 addresses (without using :: abbreviations) and use ifconfig or ip (from +the iproute package) to give the virtual network interface corresponding IPv6 +addresses. tinc does not provide autoconfiguration for IPv6 hosts. Consider +using radvd or zebra if you need it. + +It is also possible to make tunnels to other tinc daemons over IPv6 networks, +if the operating system supports IPv6. tinc will automatically use both IPv6 +and IPv4 when available, but this can be changed by adding the option +"AddressFamily = ipv4" or "AddressFamily = ipv6" to the tinc.conf file. + +Normally, when started tinc will detach and run in the background. In a native +Windows environment this means tinc will install itself as a service, which will +restart after reboots. To prevent tinc from detaching or running as a service, +use the -D option. +