README 5.6 KB

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  1. This is the README file for tinc version 1.1-cvs. Installation
  2. instructions may be found in the INSTALL file.
  3. tinc is Copyright (C) 1998-2010 by:
  4. Ivo Timmermans,
  5. Guus Sliepen <guus@tinc-vpn.org>,
  6. and others.
  7. For a complete list of authors see the AUTHORS file.
  8. This program is free software; you can redistribute it and/or modify
  9. it under the terms of the GNU General Public License as published by
  10. the Free Software Foundation; either version 2 of the License, or (at
  11. your option) any later version. See the file COPYING for more details.
  12. Security statement
  13. ------------------
  14. In August 2000, we discovered the existence of a security hole in all versions
  15. of tinc up to and including 1.0pre2. This had to do with the way we exchanged
  16. keys. Since then, we have been working on a new authentication scheme to make
  17. tinc as secure as possible. The current version uses the OpenSSL library and
  18. uses strong authentication with RSA keys.
  19. On the 29th of December 2001, Jerome Etienne posted a security analysis of tinc
  20. 1.0pre4. Due to a lack of sequence numbers and a message authentication code
  21. for each packet, an attacker could possibly disrupt certain network services or
  22. launch a denial of service attack by replaying intercepted packets. The current
  23. version adds sequence numbers and message authentication codes to prevent such
  24. attacks.
  25. On September the 15th of 2003, Peter Gutmann contacted us and showed us a
  26. writeup describing various security issues in several VPN daemons. He showed
  27. that tinc lacks perfect forward security, the connection authentication could
  28. be done more properly, that the sequence number we use as an IV is not the best
  29. practice and that the default length of the HMAC for packets is too short in
  30. his opinion. We do not know of a way to exploit these weaknesses, but we will
  31. address these issues in tinc 2.0.
  32. Cryptography is a hard thing to get right. We cannot make any
  33. guarantees. Time, review and feedback are the only things that can
  34. prove the security of any cryptographic product. If you wish to review
  35. tinc or give us feedback, you are stronly encouraged to do so.
  36. Changes to configuration file format since 1.0pre5
  37. --------------------------------------------------
  38. Some configuration variables have different names now. Most notably "TapDevice"
  39. should be changed into "Device", and "Device" should be changed into
  40. "BindToDevice".
  41. Compatibility
  42. -------------
  43. Version 1.1-cvs is compatible with 1.0pre8, 1.0 and later, but not with older
  44. versions of tinc.
  45. Requirements
  46. ------------
  47. Since 1.0pre3, we use OpenSSL for all cryptographic functions. So you
  48. need to install this library first; grab it from
  49. http://www.openssl.org/. You will need version 0.9.7 or later. If
  50. this library is not installed on you system, configure will fail. The
  51. manual in doc/tinc.texi contains more detailed information on how to
  52. install this library.
  53. Since 1.0pre6, the zlib library is used for optional compression. You need this
  54. library whether or not you plan to enable the compression. You can find it at
  55. http://www.gzip.org/zlib/. Because of a possible exploit in earlier versions we
  56. recommand that you download version 1.1.4 or later.
  57. Since 1.0, the lzo library is also used for optional compression. You need this
  58. library whether or not you plan to enable compression. You can find it at
  59. http://www.oberhumer.com/opensource/lzo/.
  60. In order to compile tinc, you will need a GNU C compiler environment.
  61. Features
  62. --------
  63. This version of tinc supports multiple virtual networks at once. To
  64. use this feature, you may supply a netname via the -n or --net
  65. options. The standard locations for the config files will then be
  66. /etc/tinc/<net>/.
  67. tincd regenerates its encryption key pairs. It does this on the first
  68. activity after the keys have expired. This period is adjustable in the
  69. configuration file, and the default time is 3600 seconds (one hour).
  70. This version supports multiple subnets at once. They are also sorted
  71. on subnet mask size. This means that it is possible to have
  72. overlapping subnets on the VPN, as long as their subnet mask sizes
  73. differ.
  74. Since pre5, tinc can operate in several routing modes. The default mode,
  75. "router", works exactly like the older version, and uses Subnet lines to
  76. determine the destination of packets. The other two modes, "switch" and "hub",
  77. allow the tinc daemons to work together like a single network switch or hub.
  78. This is useful for bridging networks. The latter modes only work properly on
  79. Linux, FreeBSD and Windows.
  80. The algorithms used for encryption and generating message authentication codes
  81. can now be changed in the configuration files. All cipher and digest algorithms
  82. supported by OpenSSL can be used. Useful ciphers are "blowfish" (default),
  83. "bf-ofb", "des", "des3", etcetera. Useful digests are "sha1" (default), "md5",
  84. etcetera.
  85. Support for routing IPv6 packets has been added. Just add Subnet lines with
  86. IPv6 addresses (without using :: abbreviations) and use ifconfig or ip (from
  87. the iproute package) to give the virtual network interface corresponding IPv6
  88. addresses. tinc does not provide autoconfiguration for IPv6 hosts, if you need
  89. it use radvd or zebra.
  90. It is also possible to make tunnels to other tinc daemons over IPv6 networks,
  91. if the operating system supports IPv6. tinc will automatically use both IPv6
  92. and IPv4 when available, but this can be changed by adding the option
  93. "AddressFamily = ipv4" or "AddressFamily = ipv6" to the tinc.conf file.
  94. Normally, when started tinc will detach and run in the background. In a native
  95. Windows environment this means tinc will intall itself as a service, which will
  96. restart after reboots. To prevent tinc from detaching or running as a service,
  97. use the -D option.