This is the info manual for @value{PACKAGE} version @value{VERSION}, a Virtual Private Network daemon.
-Copyright @copyright{} 1998-2012 Ivo Timmermans,
+Copyright @copyright{} 1998-2015 Ivo Timmermans,
Guus Sliepen <guus@@tinc-vpn.org> and
Wessel Dankers <wsl@@tinc-vpn.org>.
@end ifinfo
+@afourpaper
+@paragraphindent none
+@finalout
+
@titlepage
@title tinc Manual
@subtitle Setting up a Virtual Private Network with tinc
@vskip 0pt plus 1filll
This is the info manual for @value{PACKAGE} version @value{VERSION}, a Virtual Private Network daemon.
-Copyright @copyright{} 1998-2012 Ivo Timmermans,
+Copyright @copyright{} 1998-2015 Ivo Timmermans,
Guus Sliepen <guus@@tinc-vpn.org> and
Wessel Dankers <wsl@@tinc-vpn.org>.
* Installation::
* Configuration::
* Running tinc::
+* Controlling tinc::
* Technical information::
* Platform specific information::
* About us::
@cindex release
For an up to date list of supported platforms, please check the list on
our website:
-@uref{http://www.tinc-vpn.org/platforms}.
+@uref{https://www.tinc-vpn.org/platforms/}.
@c
@c
@subsection Configuration of FreeBSD kernels
For FreeBSD version 4.1 and higher, tun and tap drivers are included in the default kernel configuration.
-The tap driver can be loaded with @code{kldload if_tap}, or by adding @code{if_tap_load="YES"} to @file{/boot/loader.conf}.
+The tap driver can be loaded with @code{kldload if_tap}, or by adding @code{if_tap_load="YES"} to @file{/boot/loader.conf}.
@c ==================================================================
@node Configuration of OpenBSD kernels
@subsection Configuration of OpenBSD kernels
-For OpenBSD version 2.9 and higher,
-the tun driver is included in the default kernel configuration.
-There is also a kernel patch from @uref{http://diehard.n-r-g.com/stuff/openbsd/}
-which adds a tap device to OpenBSD which should work with tinc,
-but with recent versions of OpenBSD,
-a tun device can act as a tap device by setting the link0 option with ifconfig.
+Recent versions of OpenBSD come with both tun and tap devices enabled in the default kernel configuration.
@c ==================================================================
For Solaris 8 (SunOS 5.8) and higher,
the tun driver may or may not be included in the default kernel configuration.
If it isn't, the source can be downloaded from @uref{http://vtun.sourceforge.net/tun/}.
-For x86 and sparc64 architectures, precompiled versions can be found at @uref{http://www.monkey.org/~dugsong/fragroute/}.
+For x86 and sparc64 architectures, precompiled versions can be found at @uref{https://www.monkey.org/~dugsong/fragroute/}.
If the @file{net/if_tun.h} header file is missing, install it from the source package.
@subsection Configuration of Darwin (MacOS/X) kernels
Tinc on Darwin relies on a tunnel driver for its data acquisition from the kernel.
-Tinc supports either the driver from @uref{http://tuntaposx.sourceforge.net/},
+OS X version 10.6.8 and later have a built-in tun driver called "utun".
+Tinc also supports the driver from @uref{http://tuntaposx.sourceforge.net/},
which supports both tun and tap style devices,
-and also the driver from from @uref{http://chrisp.de/en/projects/tunnel.html}.
-The former driver is recommended.
-The tunnel driver must be loaded before starting tinc with the following command:
-@example
-kmodload tunnel
-@end example
+By default, tinc expects the tuntaposx driver to be installed.
+To use the utun driver, set add @code{Device = utunX} to @file{tinc.conf},
+where X is the desired number for the utun interface.
+You can also omit the number, in which case the first free number will be chosen.
@c ==================================================================
@subsection Configuration of Windows
You will need to install the latest TAP-Win32 driver from OpenVPN.
-You can download it from @uref{http://openvpn.sourceforge.net}.
+You can download it from @uref{https://openvpn.net/index.php/open-source/downloads.html}.
Using the Network Connections control panel,
configure the TAP-Win32 network interface in the same way as you would do from the tinc-up script,
as explained in the rest of the documentation.
@cindex requirements
@cindex libraries
-Before you can configure or build tinc, you need to have the OpenSSL,
-zlib and lzo libraries installed on your system. If you try to configure tinc without
-having them installed, configure will give you an error message, and stop.
+Before you can configure or build tinc, you need to have the LibreSSL or OpenSSL, zlib,
+lzo, curses and readline libraries installed on your system. If you try to
+configure tinc without having them installed, configure will give you an error
+message, and stop.
@menu
-* OpenSSL::
+* LibreSSL/OpenSSL::
* zlib::
* lzo::
+* libcurses::
+* libreadline::
@end menu
@c ==================================================================
-@node OpenSSL
-@subsection OpenSSL
+@node LibreSSL/OpenSSL
+@subsection LibreSSL/OpenSSL
+@cindex LibreSSL
@cindex OpenSSL
For all cryptography-related functions, tinc uses the functions provided
-by the OpenSSL library.
+by the LibreSSL or the OpenSSL library.
If this library is not installed, you wil get an error when configuring
-tinc for build. Support for running tinc without having OpenSSL
+tinc for build. Support for running tinc with other cryptographic libraries
installed @emph{may} be added in the future.
You can use your operating system's package manager to install this if
available. Make sure you install the development AND runtime versions
of this package.
-If you have to install OpenSSL manually, you can get the source code
-from @url{http://www.openssl.org/}. Instructions on how to configure,
-build and install this package are included within the package. Please
-make sure you build development and runtime libraries (which is the
+If your operating system comes neither with LibreSSL or OpenSSL, you have to
+install one manually. It is recommended that you get the latest version of
+LibreSSL from @url{http://www.libressl.org/}. Instructions on how to
+configure, build and install this package are included within the package.
+Please make sure you build development and runtime libraries (which is the
default).
-If you installed the OpenSSL libraries from source, it may be necessary
+If you installed the LibreSSL or OpenSSL libraries from source, it may be necessary
to let configure know where they are, by passing configure one of the
---with-openssl-* parameters.
+--with-openssl-* parameters. Note that you even have to use --with-openssl-* if you
+are using LibreSSL.
@example
---with-openssl=DIR OpenSSL library and headers prefix
---with-openssl-include=DIR OpenSSL headers directory
+--with-openssl=DIR LibreSSL/OpenSSL library and headers prefix
+--with-openssl-include=DIR LibreSSL/OpenSSL headers directory
(Default is OPENSSL_DIR/include)
---with-openssl-lib=DIR OpenSSL library directory
+--with-openssl-lib=DIR LibreSSL/OpenSSL library directory
(Default is OPENSSL_DIR/lib)
@end example
The complete source code of tinc is covered by the GNU GPL version 2.
Since the license under which OpenSSL is distributed is not directly
compatible with the terms of the GNU GPL
-@uref{http://www.openssl.org/support/faq.html#LEGAL2}, we
+@uref{https://www.openssl.org/support/faq.html#LEGAL2}, we
include an exemption to the GPL (see also the file COPYING.README) to allow
everyone to create a statically or dynamically linked executable:
@quotation
Hereby I grant a special exception to the tinc VPN project
-(http://www.tinc-vpn.org/) to link the LZO library with the OpenSSL library
-(http://www.openssl.org).
+(https://www.tinc-vpn.org/) to link the LZO library with the OpenSSL library
+(https://www.openssl.org).
Markus F.X.J. Oberhumer
@end quotation
For the optional compression of UDP packets, tinc uses the functions provided
by the zlib library.
-If this library is not installed, you wil get an error when configuring
-tinc for build. Support for running tinc without having zlib
-installed @emph{may} be added in the future.
+If this library is not installed, you wil get an error when running the
+configure script. You can either install the zlib library, or disable support
+for zlib compression by using the "--disable-zlib" option when running the
+configure script. Note that if you disable support for zlib, the resulting
+binary will not work correctly on VPNs where zlib compression is used.
You can use your operating system's package manager to install this if
available. Make sure you install the development AND runtime versions
of this package.
If you have to install zlib manually, you can get the source code
-from @url{http://www.gzip.org/zlib/}. Instructions on how to configure,
+from @url{http://www.zlib.net/}. Instructions on how to configure,
build and install this package are included within the package. Please
make sure you build development and runtime libraries (which is the
default).
@subsection lzo
@cindex lzo
-Another form of compression is offered using the lzo library.
+Another form of compression is offered using the LZO library.
-If this library is not installed, you wil get an error when configuring
-tinc for build. Support for running tinc without having lzo
-installed @emph{may} be added in the future.
+If this library is not installed, you wil get an error when running the
+configure script. You can either install the LZO library, or disable support
+for LZO compression by using the "--disable-lzo" option when running the
+configure script. Note that if you disable support for LZO, the resulting
+binary will not work correctly on VPNs where LZO compression is used.
You can use your operating system's package manager to install this if
available. Make sure you install the development AND runtime versions
of this package.
If you have to install lzo manually, you can get the source code
-from @url{http://www.oberhumer.com/opensource/lzo/}. Instructions on how to configure,
+from @url{https://www.oberhumer.com/opensource/lzo/}. Instructions on how to configure,
build and install this package are included within the package. Please
make sure you build development and runtime libraries (which is the
default).
+@c ==================================================================
+@node libcurses
+@subsection libcurses
+
+@cindex libcurses
+For the "tinc top" command, tinc requires a curses library.
+
+If this library is not installed, you wil get an error when running the
+configure script. You can either install a suitable curses library, or disable
+all functionality that depends on a curses library by using the
+"--disable-curses" option when running the configure script.
+
+There are several curses libraries. It is recommended that you install
+"ncurses" (@url{http://invisible-island.net/ncurses/}),
+however other curses libraries should also work.
+In particular, "PDCurses" (@url{http://pdcurses.sourceforge.net/})
+is recommended if you want to compile tinc for Windows.
+
+You can use your operating system's package manager to install this if
+available. Make sure you install the development AND runtime versions
+of this package.
+
+
+@c ==================================================================
+@node libreadline
+@subsection libreadline
+
+@cindex libreadline
+For the "tinc" command's shell functionality, tinc uses the readline library.
+
+If this library is not installed, you wil get an error when running the
+configure script. You can either install a suitable readline library, or
+disable all functionality that depends on a readline library by using the
+"--disable-readline" option when running the configure script.
+
+You can use your operating system's package manager to install this if
+available. Make sure you install the development AND runtime versions
+of this package.
+
+If you have to install libreadline manually, you can get the source code from
+@url{http://www.gnu.org/software/readline/}. Instructions on how to configure,
+build and install this package are included within the package. Please make
+sure you build development and runtime libraries (which is the default).
+
+
@c
@c
@c
If you cannot use one of the precompiled packages, or you want to compile tinc
for yourself, you can use the source. The source is distributed under
the GNU General Public License (GPL). Download the source from the
-@uref{http://www.tinc-vpn.org/download, download page}, which has
-the checksums of these files listed; you may wish to check these with
-md5sum before continuing.
+@uref{https://www.tinc-vpn.org/download/, download page}.
Tinc comes in a convenient autoconf/automake package, which you can just
treat the same as any other package. Which is just untar it, type
@node Darwin (MacOS/X) build environment
@subsection Darwin (MacOS/X) build environment
-In order to build tinc on Darwin, you need to install the MacOS/X Developer Tools
-from @uref{http://developer.apple.com/tools/macosxtools.html} and
-a recent version of Fink from @uref{http://fink.sourceforge.net/}.
+In order to build tinc on Darwin, you need to install Xcode from @uref{https://developer.apple.com/xcode/}.
+It might also help to install a recent version of Fink from @uref{http://www.finkproject.org/}.
-After installation use fink to download and install the following packages:
-autoconf25, automake, dlcompat, m4, openssl, zlib and lzo.
+You need to download and install LibreSSL (or OpenSSL) and LZO,
+either directly from their websites (see @ref{Libraries}) or using Fink.
@c ==================================================================
@node Cygwin (Windows) build environment
@subsection Cygwin (Windows) build environment
If Cygwin hasn't already been installed, install it directly from
-@uref{http://www.cygwin.com/}.
+@uref{https://www.cygwin.com/}.
When tinc is compiled in a Cygwin environment, it can only be run in this environment,
but all programs, including those started outside the Cygwin environment, will be able to use the VPN.
@subsection MinGW (Windows) build environment
You will need to install the MinGW environment from @uref{http://www.mingw.org}.
+You also need to download and install LibreSSL (or OpenSSL) and LZO.
When tinc is compiled using MinGW it runs natively under Windows,
it is not necessary to keep MinGW installed.
* Multiple networks::
* How connections work::
* Configuration files::
-* Generating keypairs::
* Network interfaces::
* Example configuration::
@end menu
Make sure you have an adequate understanding of networks in general.
@cindex Network Administrators Guide
A good resource on networking is the
-@uref{http://www.linuxdoc.org/LDP/nag2/, Linux Network Administrators Guide}.
+@uref{http://www.tldp.org/LDP/nag2/, Linux Network Administrators Guide}.
If you have everything clearly pictured in your mind,
proceed in the following order:
-First, generate the configuration files (@file{tinc.conf}, your host configuration file, @file{tinc-up} and perhaps @file{tinc-down}).
-Then generate the keypairs.
-Finally, distribute the host configuration files.
+First, create the initial configuration files and public/private keypairs using the following command:
+@example
+tinc -n @var{NETNAME} init @var{NAME}
+@end example
+Second, use @samp{tinc -n @var{NETNAME} add ...} to further configure tinc.
+Finally, export your host configuration file using @samp{tinc -n @var{NETNAME} export} and send it to those
+people or computers you want tinc to connect to.
+They should send you their host configuration file back, which you can import using @samp{tinc -n @var{NETNAME} import}.
+
These steps are described in the subsections below.
@cindex multiple networks
@cindex netname
+
In order to allow you to run more than one tinc daemon on one computer,
for instance if your computer is part of more than one VPN,
you can assign a @var{netname} to your VPN.
It is not required if you only run one tinc daemon,
-it doesn't even have to be the same on all the sites of your VPN,
+it doesn't even have to be the same on all the nodes of your VPN,
but it is recommended that you choose one anyway.
We will asume you use a netname throughout this document.
-This means that you call tincd with the -n argument,
-which will assign a netname to this daemon.
+This means that you call tinc with the -n argument,
+which will specify the netname.
-The effect of this is that the daemon will set its configuration
-root to @file{@value{sysconfdir}/tinc/@var{netname}/}, where @var{netname} is your argument to the -n
-option. You'll notice that it appears in syslog as @file{tinc.@var{netname}}.
+The effect of this option is that tinc will set its configuration
+root to @file{@value{sysconfdir}/tinc/@var{netname}/}, where @var{netname} is your argument to the -n option.
+You will also notice that log messages it appears in syslog as coming from @file{tinc.@var{netname}},
+and on Linux, unless specified otherwise, the name of the virtual network interface will be the same as the network name.
However, it is not strictly necessary that you call tinc with the -n
-option. In this case, the network name would just be empty, and it will
-be used as such. tinc now looks for files in @file{@value{sysconfdir}/tinc/}, instead of
-@file{@value{sysconfdir}/tinc/@var{netname}/}; the configuration file should be @file{@value{sysconfdir}/tinc/tinc.conf},
-and the host configuration files are now expected to be in @file{@value{sysconfdir}/tinc/hosts/}.
-
-But it is highly recommended that you use this feature of tinc, because
-it will be so much clearer whom your daemon talks to. Hence, we will
-assume that you use it.
+option. If you do not use it, the network name will just be empty, and
+tinc will look for files in @file{@value{sysconfdir}/tinc/} instead of
+@file{@value{sysconfdir}/tinc/@var{netname}/};
+the configuration file will then be @file{@value{sysconfdir}/tinc/tinc.conf},
+and the host configuration files are expected to be in @file{@value{sysconfdir}/tinc/hosts/}.
@c ==================================================================
and one which does specify such a value as a client.
It does not matter if two tinc daemons have a `ConnectTo' value pointing to each other however.
+Connections specified using `ConnectTo' are so-called meta-connections.
+Tinc daemons exchange information about all other daemon they know about via these meta-connections.
+After learning about all the daemons in the VPN,
+tinc will create other connections as necessary in order to communicate with them.
+For example, if there are three daemons named A, B and C, and A has @samp{ConnectTo = B} in its tinc.conf file,
+and C has @samp{ConnectTo = B} in its tinc.conf file, then A will learn about C from B,
+and will be able to exchange VPN packets with C without the need to have @samp{ConnectTo = C} in its tinc.conf file.
+
+It could be that some daemons are located behind a Network Address Translation (NAT) device, or behind a firewall.
+In the above scenario with three daemons, if A and C are behind a NAT,
+B will automatically help A and C punch holes through their NAT,
+in a way similar to the STUN protocol, so that A and C can still communicate with each other directly.
+It is not always possible to do this however, and firewalls might also prevent direct communication.
+In that case, VPN packets between A and C will be forwarded by B.
+
+In effect, all nodes in the VPN will be able to talk to each other, as long as
+their is a path of meta-connections between them, and whenever possible, two
+nodes will communicate with each other directly.
+
@c ==================================================================
@node Configuration files
@file{@value{sysconfdir}/tinc/@var{netname}/tinc.conf} and at least one other file in the directory
@file{@value{sysconfdir}/tinc/@var{netname}/hosts/}.
+An optionnal directory @file{@value{sysconfdir}/tinc/@var{netname}/conf.d} can be added from which
+any .conf file will be read.
+
These file consists of comments (lines started with a #) or assignments
in the form of
put host specific configuration options in the host configuration file, as this
makes it easy to exchange with other nodes.
-In this section all valid variables are listed in alphabetical order.
+You can edit the config file manually, but it is recommended that you use
+the tinc command to change configuration variables for you.
+
+In the following two subsections all valid variables are listed in alphabetical order.
The default value is given between parentheses,
other comments are between square brackets.
If any is selected, then depending on the operating system
both IPv4 and IPv6 or just IPv6 listening sockets will be created.
-@cindex BindToAddress
-@item BindToAddress = <@var{address}> [<@var{port}>] [experimental]
-If your computer has more than one IPv4 or IPv6 address, tinc
-will by default listen on all of them for incoming connections.
-Multiple BindToAddress variables may be specified,
-in which case listening sockets for each specified address are made.
-
-If no @var{port} is specified, the socket will be bound to the port specified by the Port option,
-or to port 655 if neither is given.
-To only bind to a specific port but not to a specific address, use "*" for the @var{address}.
+@cindex AutoConnect
+@item AutoConnect = <yes|no> (no) [experimental]
+If set to yes, tinc will automatically set up meta connections to other nodes,
+without requiring @var{ConnectTo} variables.
-This option may not work on all platforms.
+@cindex BindToAddress
+@item BindToAddress = <@var{address}> [<@var{port}>]
+This is the same as ListenAddress, however the address given with the BindToAddress option
+will also be used for outgoing connections.
+This is useful if your computer has more than one IPv4 or IPv6 address,
+and you want tinc to only use a specific one for outgoing packets.
@cindex BindToInterface
@item BindToInterface = <@var{interface}> [experimental]
variable.
This option may not work on all platforms.
+Also, on some platforms it will not actually bind to an interface,
+but rather to the address that the interface has at the moment a socket is created.
@cindex Broadcast
@item Broadcast = <no | mst | direct> (mst) [experimental]
If the IndirectData option is also set, broadcast packets will only be sent to nodes which we have a meta connection to.
@end table
+@cindex BroadcastSubnet
+@item BroadcastSubnet = @var{address}[/@var{prefixlength}]
+Declares a broadcast subnet.
+Any packet with a destination address falling into such a subnet will be routed as a broadcast
+(provided all nodes have it declared).
+This is most useful to declare subnet broadcast addresses (e.g. 10.42.255.255),
+otherwise tinc won't know what to do with them.
+
+Note that global broadcast addresses (MAC ff:ff:ff:ff:ff:ff, IPv4 255.255.255.255),
+as well as multicast space (IPv4 224.0.0.0/4, IPv6 ff00::/8)
+are always considered broadcast addresses and don't need to be declared.
+
@cindex ConnectTo
@item ConnectTo = <@var{name}>
Specifies which other tinc daemon to connect to on startup.
The names should be known to this tinc daemon
(i.e., there should be a host configuration file for the name on the ConnectTo line).
-If you don't specify a host with ConnectTo,
+If you don't specify a host with ConnectTo and don't enable AutoConnect,
tinc won't try to connect to other daemons at all,
and will instead just listen for incoming connections.
Note that you can only use one device per daemon.
See also @ref{Device files}.
+@cindex DeviceStandby
+@item DeviceStandby = <yes | no> (no)
+When disabled, tinc calls @file{tinc-up} on startup, and @file{tinc-down} on shutdown.
+When enabled, tinc will only call @file{tinc-up} when at least one node is reachable,
+and will call @file{tinc-down} as soon as no nodes are reachable.
+On Windows, this also determines when the virtual network interface "cable" is "plugged".
+
@cindex DeviceType
@item DeviceType = <@var{type}> (platform dependent)
The type of the virtual network device.
followed by an IP header.
This mode should support both IPv4 and IPv6 packets.
+@cindex utun
+@item utun (OS X)
+Set type to utun.
+This is only supported on OS X version 10.6.8 and higher, but doesn't require the tuntaposx module.
+This mode should support both IPv4 and IPv6 packets.
+
@item tap (BSD and Linux)
Set type to tap.
Tinc will expect packets read from the virtual network device
When combined with the IndirectData option,
packets for nodes for which we do not have a meta connection with are also dropped.
+@cindex Ed25519PrivateKeyFile
+@item Ed25519PrivateKeyFile = <@var{path}> (@file{@value{sysconfdir}/tinc/@var{netname}/ed25519_key.priv})
+The file in which the private Ed25519 key of this tinc daemon resides.
+This is only used if ExperimentalProtocol is enabled.
+
+@cindex ExperimentalProtocol
+@item ExperimentalProtocol = <yes|no> (yes)
+When this option is enabled, the SPTPS protocol will be used when connecting to nodes that also support it.
+Ephemeral ECDH will be used for key exchanges,
+and Ed25519 will be used instead of RSA for authentication.
+When enabled, an Ed25519 key must have been generated before with
+@samp{tinc generate-ed25519-keys}.
+
@cindex Forwarding
@item Forwarding = <off|internal|kernel> (internal) [experimental]
This option selects the way indirect packets are forwarded.
and can also help debugging.
@end table
-@cindex GraphDumpFile
-@item GraphDumpFile = <@var{filename}> [experimental]
-If this option is present,
-tinc will dump the current network graph to the file @var{filename}
-every minute, unless there were no changes to the graph.
-The file is in a format that can be read by graphviz tools.
-If @var{filename} starts with a pipe symbol |,
-then the rest of the filename is interpreted as a shell command
-that is executed, the graph is then sent to stdin.
-
@cindex Hostnames
@item Hostnames = <yes|no> (no)
This option selects whether IP addresses (both real and on the VPN)
Under Windows, this variable is used to select which network interface will be used.
If you specified a Device, this variable is almost always already correctly set.
+@cindex ListenAddress
+@item ListenAddress = <@var{address}> [<@var{port}>]
+If your computer has more than one IPv4 or IPv6 address, tinc
+will by default listen on all of them for incoming connections.
+This option can be used to restrict which addresses tinc listens on.
+Multiple ListenAddress variables may be specified,
+in which case listening sockets for each specified address are made.
+
+If no @var{port} is specified, the socket will listen on the port specified by the Port option,
+or to port 655 if neither is given.
+To only listen on a specific port but not to a specific address, use "*" for the @var{address}.
+
@cindex LocalDiscovery
-@item LocalDiscovery = <yes | no> (no) [experimental]
+@item LocalDiscovery = <yes | no> (no)
When enabled, tinc will try to detect peers that are on the same local network.
This will allow direct communication using LAN addresses, even if both peers are behind a NAT
and they only ConnectTo a third node outside the NAT,
which normally would prevent the peers from learning each other's LAN address.
-Currently, local discovery is implemented by sending broadcast packets to the LAN during path MTU discovery.
-This feature may not work in all possible situations.
+Currently, local discovery is implemented by sending some packets to the local address of the node during UDP discovery.
+This will not work with old nodes that don't transmit their local address.
+
+@cindex LocalDiscoveryAddress
+@item LocalDiscoveryAddress <@var{address}>
+If this variable is specified, local discovery packets are sent to the given @var{address}.
@cindex Mode
@item Mode = <router|switch|hub> (router)
@item router
In this mode Subnet
variables in the host configuration files will be used to form a routing table.
-Only unicast packets of routable protocols (IPv4 and IPv6) are supported in this mode.
+Only packets of routable protocols (IPv4 and IPv6) are supported in this mode.
This is the default mode, and unless you really know you need another mode, don't change it.
This option controls the amount of time MAC addresses are kept before they are removed.
This only has effect when Mode is set to "switch".
+@cindex MaxConnectionBurst
+@item MaxConnectionBurst = <@var{count}> (100)
+This option controls how many connections tinc accepts in quick succession.
+If there are more connections than the given number in a short time interval,
+tinc will reduce the number of accepted connections to only one per second,
+until the burst has passed.
+
@cindex Name
@item Name = <@var{name}> [required]
This is a symbolic name for this connection.
-The name should consist only of alfanumeric and underscore characters (a-z, A-Z, 0-9 and _).
+The name must consist only of alfanumeric and underscore characters (a-z, A-Z, 0-9 and _), and is case sensitive.
If Name starts with a $, then the contents of the environment variable that follows will be used.
In that case, invalid characters will be converted to underscores.
If Name is $HOST, but no such environment variable exist,
-the hostname will be read using the gethostnname() system call.
+the hostname will be read using the gethostname() system call.
@cindex PingInterval
@item PingInterval = <@var{seconds}> (60)
@cindex PrivateKeyFile
@item PrivateKeyFile = <@var{path}> (@file{@value{sysconfdir}/tinc/@var{netname}/rsa_key.priv})
This is the full path name of the RSA private key file that was
-generated by @samp{tincd --generate-keys}. It must be a full path, not a
+generated by @samp{tinc generate-keys}. It must be a full path, not a
relative directory.
-Note that there must be exactly one of PrivateKey
-or PrivateKeyFile
-specified in the configuration file.
-
@cindex ProcessPriority
@item ProcessPriority = <low|normal|high>
When this option is used the priority of the tincd process will be adjusted.
Increasing the priority may help to reduce latency and packet loss on the VPN.
@cindex Proxy
-@item Proxy = socks4 | socks4 | http | exec @var{...} [experimental]
+@item Proxy = socks4 | socks5 | http | exec @var{...} [experimental]
Use a proxy when making outgoing connections.
The following proxy types are currently supported:
Optionally, a @var{username} can be supplied which will be passed on to the proxy server.
@cindex socks5
-@item socks4 <@var{address}> <@var{port}> [<@var{username}> <@var{password}>]
+@item socks5 <@var{address}> <@var{port}> [<@var{username}> <@var{password}>]
Connect to the proxy using the SOCKS version 5 protocol.
If a @var{username} and @var{password} are given, basic username/password authentication will be used,
otherwise no authentication will be used.
@end table
@cindex ReplayWindow
-@item ReplayWindow = <bytes> (16)
+@item ReplayWindow = <bytes> (32)
This is the size of the replay tracking window for each remote node, in bytes.
The window is a bitfield which tracks 1 packet per bit, so for example
-the default setting of 16 will track up to 128 packets in the window. In high
+the default setting of 32 will track up to 256 packets in the window. In high
bandwidth scenarios, setting this to a higher value can reduce packet loss from
the interaction of replay tracking with underlying real packet loss and/or
reordering. Setting this to zero will disable replay tracking completely and
pass all traffic, but leaves tinc vulnerable to replay-based attacks on your
traffic.
-
@cindex StrictSubnets
-@item StrictSubnets <yes|no> (no) [experimental]
+@item StrictSubnets = <yes|no> (no) [experimental]
When this option is enabled tinc will only use Subnet statements which are
present in the host config files in the local
@file{@value{sysconfdir}/tinc/@var{netname}/hosts/} directory.
+Subnets learned via connections to other nodes and which are not
+present in the local host config files are ignored.
@cindex TunnelServer
@item TunnelServer = <yes|no> (no) [experimental]
@file{@value{sysconfdir}/tinc/@var{netname}/hosts/} directory.
Setting this options also implicitly sets StrictSubnets.
+@cindex UDPDiscovey
+@item UDPDiscovery = <yes|no> (yes)
+When this option is enabled tinc will try to establish UDP connectivity to nodes,
+using TCP while it determines if a node is reachable over UDP. If it is disabled,
+tinc always assumes a node is reachable over UDP.
+Note that tinc will never use UDP with nodes that have TCPOnly enabled.
+
+@cindex UDPDiscoveryKeepaliveInterval
+@item UDPDiscoveryKeepaliveInterval = <seconds> (9)
+The minimum amount of time between sending UDP ping datagrams to check UDP connectivity once it has been established.
+Note that these pings are large, since they are used to verify link MTU as well.
+
+@cindex UDPDiscoveryInterval
+@item UDPDiscoveryInterval = <seconds> (2)
+The minimum amount of time between sending UDP ping datagrams to try to establish UDP connectivity.
+
+@cindex UDPDiscoveryTimeout
+@item UDPDiscoveryTimeout = <seconds> (30)
+If tinc doesn't receive any UDP ping replies over the specified interval,
+it will assume UDP communication is broken and will fall back to TCP.
+
+@cindex UDPInfoInterval
+@item UDPInfoInterval = <seconds> (5)
+The minimum amount of time between sending periodic updates about UDP addresses, which are mostly useful for UDP hole punching.
+
@cindex UDPRcvBuf
-@item UDPRcvBuf = <bytes> (OS default)
+@item UDPRcvBuf = <bytes> (1048576)
Sets the socket receive buffer size for the UDP socket, in bytes.
-If unset, the default buffer size will be used by the operating system.
+If set to zero, the default buffer size will be used by the operating system.
+Note: this setting can have a significant impact on performance, especially raw throughput.
@cindex UDPSndBuf
-@item UDPSndBuf = <bytes> Pq OS default
+@item UDPSndBuf = <bytes> (1048576)
Sets the socket send buffer size for the UDP socket, in bytes.
-If unset, the default buffer size will be used by the operating system.
+If set to zero, the default buffer size will be used by the operating system.
+Note: this setting can have a significant impact on performance, especially raw throughput.
+
+@cindex UPnP
+@item UPnP = <yes|udponly|no> (no)
+If this option is enabled then tinc will search for UPnP-IGD devices on the local network.
+It will then create and maintain port mappings for tinc's listening TCP and UDP ports.
+If set to "udponly", tinc will only create a mapping for its UDP (data) port, not for its TCP (metaconnection) port.
+Note that tinc must have been built with miniupnpc support for this feature to be available.
+Furthermore, be advised that enabling this can have security implications, because the miniupnpc library that
+tinc uses might not be well-hardened with regard to malicious UPnP replies.
+
+@cindex UPnPDiscoverWait
+@item UPnPDiscoverWait = <seconds> (5)
+The amount of time to wait for replies when probing the local network for UPnP devices.
+
+@cindex UPnPRefreshPeriod
+@item UPnPRefreshPeriod = <seconds> (5)
+How often tinc will re-add the port mapping, in case it gets reset on the UPnP device.
+This also controls the duration of the port mapping itself, which will be set to twice that duration.
@end table
must resolve to the external IP address where the host can be reached,
not the one that is internal to the VPN.
If no port is specified, the default Port is used.
+Multiple Address variables can be specified, in which case each address will be
+tried until a working connection has been established.
@cindex Cipher
@item Cipher = <@var{cipher}> (blowfish)
-The symmetric cipher algorithm used to encrypt UDP packets.
-Any cipher supported by OpenSSL is recognized.
+The symmetric cipher algorithm used to encrypt UDP packets using the legacy protocol.
+Any cipher supported by LibreSSL or OpenSSL is recognized.
Furthermore, specifying "none" will turn off packet encryption.
It is best to use only those ciphers which support CBC mode.
+This option has no effect for connections using the SPTPS protocol, which always use AES-256-CTR.
@cindex ClampMSS
@item ClampMSS = <yes|no> (yes)
@cindex Digest
@item Digest = <@var{digest}> (sha1)
-The digest algorithm used to authenticate UDP packets.
-Any digest supported by OpenSSL is recognized.
+The digest algorithm used to authenticate UDP packets using the legacy protocol.
+Any digest supported by LibreSSL or OpenSSL is recognized.
Furthermore, specifying "none" will turn off packet authentication.
+This option has no effect for connections using the SPTPS protocol, which always use HMAC-SHA-256.
@cindex IndirectData
@item IndirectData = <yes|no> (no)
-This option specifies whether other tinc daemons besides the one you
-specified with ConnectTo can make a direct connection to you. This is
-especially useful if you are behind a firewall and it is impossible to
-make a connection from the outside to your tinc daemon. Otherwise, it
-is best to leave this option out or set it to no.
+When set to yes, other nodes which do not already have a meta connection to you
+will not try to establish direct communication with you.
+It is best to leave this option out or set it to no.
@cindex MACLength
@item MACLength = <@var{bytes}> (4)
-The length of the message authentication code used to authenticate UDP packets.
+The length of the message authentication code used to authenticate UDP packets using the legacy protocol.
Can be anything from 0
up to the length of the digest produced by the digest algorithm.
+This option has no effect for connections using the SPTPS protocol, which never truncate MACs.
@cindex PMTU
@item PMTU = <@var{mtu}> (1514)
When this option is enabled, tinc will try to discover the path MTU to this node.
After the path MTU has been discovered, it will be enforced on the VPN.
+@cindex MTUInfoInterval
+@item MTUInfoInterval = <seconds> (5)
+The minimum amount of time between sending periodic updates about relay path MTU. Useful for quickly determining MTU to indirect nodes.
+
@cindex Port
@item Port = <@var{port}> (655)
This is the port this tinc daemon listens on.
@cindex PublicKeyFile
@item PublicKeyFile = <@var{path}> [obsolete]
This is the full path name of the RSA public key file that was generated
-by @samp{tincd --generate-keys}. It must be a full path, not a relative
+by @samp{tinc generate-keys}. It must be a full path, not a relative
directory.
@cindex PEM format
Prefixlength is the number of bits set to 1 in the netmask part; for
example: netmask 255.255.255.0 would become /24, 255.255.252.0 becomes
/22. This conforms to standard CIDR notation as described in
-@uref{ftp://ftp.isi.edu/in-notes/rfc1519.txt, RFC1519}
+@uref{https://www.ietf.org/rfc/rfc1519.txt, RFC1519}
-@cindex Subnet weight
A Subnet can be given a weight to indicate its priority over identical Subnets
owned by different nodes. The default weight is 10. Lower values indicate
higher priority. Packets will be sent to the node with the highest priority,
priority will be tried, and so on.
@cindex TCPonly
-@item TCPonly = <yes|no> (no) [deprecated]
+@item TCPonly = <yes|no> (no)
If this variable is set to yes, then the packets are tunnelled over a
TCP connection instead of a UDP connection. This is especially useful
for those who want to run a tinc daemon from behind a masquerading
firewall, or if UDP packet routing is disabled somehow.
Setting this options also implicitly sets IndirectData.
-Since version 1.0.10, tinc will automatically detect whether communication via
-UDP is possible or not.
+@cindex Weight
+@item Weight = <weight>
+If this variable is set, it overrides the weight given to connections made with
+another host. A higher weight means a lower priority is given to this
+connection when broadcasting or forwarding packets.
@end table
@cindex scripts
Apart from reading the server and host configuration files,
tinc can also run scripts at certain moments.
-Under Windows (not Cygwin), the scripts should have the extension .bat.
+Below is a list of filenames of scripts and a description of when they are run.
+A script is only run if it exists and if it is executable.
+
+Scripts are run synchronously;
+this means that tinc will temporarily stop processing packets until the called script finishes executing.
+This guarantees that scripts will execute in the exact same order as the events that trigger them.
+If you need to run commands asynchronously, you have to ensure yourself that they are being run in the background.
+
+Under Windows (not Cygwin), the scripts should have the extension @file{.bat} or @file{.cmd}.
@table @file
@cindex tinc-up
started and has connected to the virtual network device.
It should be used to set up the corresponding network interface,
but can also be used to start other things.
+
Under Windows you can use the Network Connections control panel instead of creating this script.
@cindex tinc-down
@item @value{sysconfdir}/tinc/@var{netname}/subnet-down
This script is started when a Subnet becomes unreachable.
+
+@item @value{sysconfdir}/tinc/@var{netname}/invitation-created
+This script is started when a new invitation has been created.
+
+@item @value{sysconfdir}/tinc/@var{netname}/invitation-accepted
+This script is started when an invitation has been used.
+
@end table
@cindex environment variables
The scripts are started without command line arguments,
but can make use of certain environment variables.
Under UNIX like operating systems the names of environment variables must be preceded by a $ in scripts.
-Under Windows, in @file{.bat} files, they have to be put between % signs.
+Under Windows, in @file{.bat} or @file{.cmd} files, they have to be put between % signs.
@table @env
@cindex NETNAME
@item WEIGHT
When a subnet becomes (un)reachable, this is set to the subnet weight.
+@cindex INVITATION_FILE
+@item INVITATION_FILE
+When the @file{invitation-created} script is called,
+this is set to the file where the invitation details will be stored.
+
+@cindex INVITATION_URL
+@item INVITATION_URL
+When the @file{invitation-created} script is called,
+this is set to the invitation URL that has been created.
@end table
+Do not forget that under UNIX operating systems,
+you have to make the scripts executable, using the command @samp{chmod a+x script}.
+
@c ==================================================================
@node How to configure
@subsection How to configure
-@subsubheading Step 1. Creating the main configuration file
+@subsubheading Step 1. Creating initial configuration files.
+
+The initial directory structure, configuration files and public/private keypairs are created using the following command:
+
+@example
+tinc -n @var{netname} init @var{name}
+@end example
-The main configuration file will be called @file{@value{sysconfdir}/tinc/@var{netname}/tinc.conf}.
-Adapt the following example to create a basic configuration file:
+(You will need to run this as root, or use "sudo".)
+This will create the configuration directory @file{@value{sysconfdir}/tinc/@var{netname}.},
+and inside it will create another directory named @file{hosts/}.
+In the configuration directory, it will create the file @file{tinc.conf} with the following contents:
@example
-Name = @var{yourname}
-Device = @file{/dev/tap0}
+Name = @var{name}
@end example
-Then, if you know to which other tinc daemon(s) yours is going to connect,
-add `ConnectTo' values.
+It will also create private RSA and Ed25519 keys, which will be stored in the files @file{rsa_key.priv} and @file{ed25519_key.priv}.
+It will also create a host configuration file @file{hosts/@var{name}},
+which will contain the corresponding public RSA and Ed25519 keys.
+
+Finally, on UNIX operating systems, it will create an executable script @file{tinc-up},
+which will initially not do anything except warning that you should edit it.
-@subsubheading Step 2. Creating your host configuration file
+@subsubheading Step 2. Modifying the initial configuration.
-If you added a line containing `Name = yourname' in the main configuarion file,
-you will need to create a host configuration file @file{@value{sysconfdir}/tinc/@var{netname}/hosts/yourname}.
-Adapt the following example to create a host configuration file:
+Unless you want to use tinc in switch mode,
+you should now configure which range of addresses you will use on the VPN.
+Let's assume you will be part of a VPN which uses the address range 192.168.0.0/16,
+and you yourself have a smaller portion of that range: 192.168.2.0/24.
+Then you should run the following command:
@example
-Address = your.real.hostname.org
-Subnet = 192.168.1.0/24
+tinc -n @var{netname} add subnet 192.168.2.0/24
@end example
-You can also use an IP address instead of a hostname.
-The `Subnet' specifies the address range that is local for @emph{your part of the VPN only}.
-If you have multiple address ranges you can specify more than one `Subnet'.
-You might also need to add a `Port' if you want your tinc daemon to run on a different port number than the default (655).
+This will add a Subnet statement to your host configuration file.
+Try opening the file @file{@value{sysconfdir}/tinc/@var{netname}/hosts/@var{name}} in an editor.
+You should now see a file containing the public RSA and Ed25519 keys (which looks like a bunch of random characters),
+and the following line at the bottom:
+@example
+Subnet = 192.168.2.0/24
+@end example
-@c ==================================================================
-@node Generating keypairs
-@section Generating keypairs
+If you will use more than one address range, you can add more Subnets.
+For example, if you also use the IPv6 subnet fec0:0:0:2::/64, you can add it as well:
+
+@example
+tinc -n @var{netname} add subnet fec0:0:0:2::/24
+@end example
+
+This will add another line to the file @file{hosts/@var{name}}.
+If you make a mistake, you can undo it by simply using @samp{del} instead of @samp{add}.
+
+If you want other tinc daemons to create meta-connections to your daemon,
+you should add your public IP address or hostname to your host configuration file.
+For example, if your hostname is foo.example.org, run:
+
+@example
+tinc -n @var{netname} add address foo.example.org
+@end example
+
+If you already know to which daemons your daemon should make meta-connections,
+you should configure that now as well.
+Suppose you want to connect to a daemon named "bar", run:
-@cindex key generation
-Now that you have already created the main configuration file and your host configuration file,
-you can easily create a public/private keypair by entering the following command:
+@example
+tinc -n @var{netname} add connectto bar
+@end example
+
+Note that you specify the Name of the other daemon here, not an IP address or hostname!
+When you start tinc, and it tries to make a connection to "bar",
+it will look for a host configuration file named @file{hosts/bar},
+and will read Address statements and public keys from that file.
+
+@subsubheading Step 2. Exchanging configuration files.
+
+If your daemon has a ConnectTo = bar statement in its @file{tinc.conf} file,
+or if bar has a ConnectTo your daemon, then you both need each other's host configuration files.
+You should send @file{hosts/@var{name}} to bar, and bar should send you his file which you should move to @file{hosts/bar}.
+If you are on a UNIX platform, you can easily send an email containing the necessary information using the following command
+(assuming the owner of bar has the email address bar@@example.org):
@example
-tincd -n @var{netname} -K
+tinc -n @var{netname} export | mail -s "My config file" bar@@example.org
@end example
-Tinc will generate a public and a private key and ask you where to put them.
-Just press enter to accept the defaults.
+If the owner of bar does the same to send his host configuration file to you,
+you can probably pipe his email through the following command,
+or you can just start this command in a terminal and copy&paste the email:
+
+@example
+tinc -n @var{netname} import
+@end example
+
+If you are the owner of bar yourself, and you have SSH access to that computer,
+you can also swap the host configuration files using the following command:
+
+@example
+tinc -n @var{netname} export \
+ | ssh bar.example.org tinc -n @var{netname} exchange \
+ | tinc -n @var{netname} import
+@end example
+
+You should repeat this for all nodes you ConnectTo, or which ConnectTo you.
+However, remember that you do not need to ConnectTo all nodes in the VPN;
+it is only necessary to create one or a few meta-connections,
+after the connections are made tinc will learn about all the other nodes in the VPN,
+and will automatically make other connections as necessary.
@c ==================================================================
to a script named @file{@value{sysconfdir}/tinc/@var{netname}/tinc-up}.
When tinc starts, this script will be executed. When tinc exits, it will execute the script named
@file{@value{sysconfdir}/tinc/@var{netname}/tinc-down}, but normally you don't need to create that script.
+You can manually open the script in an editor, or use the following command:
-An example @file{tinc-up} script:
+@example
+tinc -n @var{netname} edit tinc-up
+@end example
+
+An example @file{tinc-up} script, that would be appropriate for the scenario in the previous section, is:
@example
#!/bin/sh
-ifconfig $INTERFACE 192.168.1.1 netmask 255.255.0.0
+ifconfig $INTERFACE 192.168.2.1 netmask 255.255.0.0
+ip addr add fec0:0:0:2::/48 dev $INTERFACE
@end example
-This script gives the interface an IP address and a netmask.
-The kernel will also automatically add a route to this interface, so normally you don't need
+The first command gives the interface an IPv4 address and a netmask.
+The kernel will also automatically add an IPv4 route to this interface, so normally you don't need
to add route commands to the @file{tinc-up} script.
The kernel will also bring the interface up after this command.
@cindex netmask
The netmask is the mask of the @emph{entire} VPN network, not just your
own subnet.
+The second command gives the interface an IPv6 address and netmask,
+which will also automatically add an IPv6 route.
+If you only want to use "ip addr" commands on Linux, don't forget that it doesn't bring the interface up, unlike ifconfig,
+so you need to add @samp{ip link set $INTERFACE up} in that case.
The exact syntax of the ifconfig and route commands differs from platform to platform.
You can look up the commands for setting addresses and adding routes in @ref{Platform specific information},
how these example host is set up. All branches use the netname `company'
for this particular VPN.
+Each branch is set up using the @samp{tinc init} and @samp{tinc config} commands,
+here we just show the end results:
+
@subsubheading For Branch A
@emph{BranchA} would be configured like this:
In @file{@value{sysconfdir}/tinc/company/tinc-up}:
@example
+#!/bin/sh
+
# Real interface of internal network:
# ifconfig eth0 10.1.54.1 netmask 255.255.0.0
@example
Name = BranchA
-Device = /dev/tap0
@end example
On all hosts, @file{@value{sysconfdir}/tinc/company/hosts/BranchA} contains:
-----END RSA PUBLIC KEY-----
@end example
-Note that the IP addresses of eth0 and tap0 are the same.
+Note that the IP addresses of eth0 and the VPN interface are the same.
This is quite possible, if you make sure that the netmasks of the interfaces are different.
-It is in fact recommended to give both real internal network interfaces and tap interfaces the same IP address,
+It is in fact recommended to give both real internal network interfaces and VPN interfaces the same IP address,
since that will make things a lot easier to remember and set up.
In @file{@value{sysconfdir}/tinc/company/tinc-up}:
@example
+#!/bin/sh
+
# Real interface of internal network:
# ifconfig eth0 10.2.43.8 netmask 255.255.0.0
@end example
Note here that the internal address (on eth0) doesn't have to be the
-same as on the tap0 device. Also, ConnectTo is given so that this node will
+same as on the VPN interface. Also, ConnectTo is given so that this node will
always try to connect to BranchA.
On all hosts, in @file{@value{sysconfdir}/tinc/company/hosts/BranchB}:
In @file{@value{sysconfdir}/tinc/company/tinc-up}:
@example
+#!/bin/sh
+
# Real interface of internal network:
# ifconfig eth0 10.3.69.254 netmask 255.255.0.0
@example
Name = BranchC
ConnectTo = BranchA
-Device = /dev/tap1
@end example
C already has another daemon that runs on port 655, so they have to
In @file{@value{sysconfdir}/tinc/company/tinc-up}:
@example
+#!/bin/sh
+
# Real interface of internal network:
# ifconfig eth0 10.4.3.32 netmask 255.255.0.0
@example
Name = BranchD
ConnectTo = BranchC
-Device = /dev/net/tun
@end example
D will be connecting to C, which has a tincd running for this network on
port 2000. It knows the port number from the host configuration file.
-Also note that since D uses the tun/tap driver, the network interface
-will not be called `tun' or `tap0' or something like that, but will
-have the same name as netname.
On all hosts, in @file{@value{sysconfdir}/tinc/company/hosts/BranchD}:
@subsubheading Key files
-A, B, C and D all have generated a public/private keypair with the following command:
+A, B, C and D all have their own public/private keypairs:
-@example
-tincd -n company -K
-@end example
-
-The private key is stored in @file{@value{sysconfdir}/tinc/company/rsa_key.priv},
-the public key is put into the host configuration file in the @file{@value{sysconfdir}/tinc/company/hosts/} directory.
-During key generation, tinc automatically guesses the right filenames based on the -n option and
-the Name directive in the @file{tinc.conf} file (if it is available).
+The private RSA key is stored in @file{@value{sysconfdir}/tinc/company/rsa_key.priv},
+the private Ed25519 key is stored in @file{@value{sysconfdir}/tinc/company/ed25519_key.priv},
+and the public RSA and Ed25519 keys are put into the host configuration file in the @file{@value{sysconfdir}/tinc/company/hosts/} directory.
@subsubheading Starting
If everything else is done, you can start tinc by typing the following command:
@example
-tincd -n @var{netname}
+tinc -n @var{netname} start
@end example
@cindex daemon
Set debug level to @var{level}. The higher the debug level, the more gets
logged. Everything goes via syslog.
-@item -k, --kill[=@var{signal}]
-Attempt to kill a running tincd (optionally with the specified @var{signal} instead of SIGTERM) and exit.
-Use it in conjunction with the -n option to make sure you kill the right tinc daemon.
-Under native Windows the optional argument is ignored,
-the service will always be stopped and removed.
-
@item -n, --net=@var{netname}
Use configuration for net @var{netname}.
This will let tinc read all configuration files from
Specifying . for @var{netname} is the same as not specifying any @var{netname}.
@xref{Multiple networks}.
-@item -K, --generate-keys[=@var{bits}]
-Generate public/private keypair of @var{bits} length. If @var{bits} is not specified,
-2048 is the default. tinc will ask where you want to store the files,
-but will default to the configuration directory (you can use the -c or -n option
-in combination with -K). After that, tinc will quit.
+@item --pidfile=@var{filename}
+Store a cookie in @var{filename} which allows tinc to authenticate.
+If unspecified, the default is
+@file{@value{localstatedir}/run/tinc.@var{netname}.pid}.
@item -o, --option=[@var{HOST}.]@var{KEY}=@var{VALUE}
Without specifying a @var{HOST}, this will set server configuration variable @var{KEY} to @var{VALUE}.
Lock tinc into main memory.
This will prevent sensitive data like shared private keys to be written to the system swap files/partitions.
+This option is not supported on all platforms.
+
@item --logfile[=@var{file}]
Write log entries to a file instead of to the system logging facility.
If @var{file} is omitted, the default is @file{@value{localstatedir}/log/tinc.@var{netname}.log}.
-@item --pidfile=@var{file}
-Write PID to @var{file} instead of @file{@value{localstatedir}/run/tinc.@var{netname}.pid}.
-
@item --bypass-security
Disables encryption and authentication.
Only useful for debugging.
Note also that tinc can't run scripts anymore (such as tinc-down or host-up),
unless it's setup to be runnable inside chroot environment.
+This option is not supported on all platforms.
@item -U, --user=@var{user}
Switch to the given @var{user} after initialization, at the same time as
chroot is performed (see --chroot above). With this option tinc drops
privileges, for added security.
+This option is not supported on all platforms.
+
@item --help
Display a short reminder of these runtime options and terminate.
If the --logfile option is used, this will also close and reopen the log file,
useful when log rotation is used.
-@item INT
-Temporarily increases debug level to 5.
-Send this signal again to revert to the original level.
-
-@item USR1
-Dumps the connection list to syslog.
-
-@item USR2
-Dumps virtual network device statistics, all known nodes, edges and subnets to syslog.
-
-@item WINCH
-Purges all information remembered about unreachable nodes.
-
@end table
@c ==================================================================
If so, check that it allows TCP and UDP traffic on port 655.
If it masquerades and the host running tinc is behind it, make sure that it forwards TCP and UDP traffic to port 655 to the host running tinc.
You can add @samp{TCPOnly = yes} to your host config file to force tinc to only use a single TCP connection,
-this works through most firewalls and NATs. Since version 1.0.10, tinc will automatically fall back to TCP if direct communication via UDP is not possible.
+this works through most firewalls and NATs.
@end itemize
level of 5 or higher!
@item Chances are that a @samp{Subnet = ...} line in the host configuration file of this tinc daemon is wrong.
Change it to a subnet that is accepted locally by another interface,
-or if that is not the case, try changing the prefix length into /32.
+or if that is not the case, try changing the prefix length into /32.
@end itemize
@item Node foo (1.2.3.4) is not reachable
@itemize
@item If you see this only sporadically, it is harmless and caused by a node sending packets using an old key.
+@item If you see this often and another node is not reachable anymore, then a NAT (masquerading firewall) is changing the source address of UDP packets.
+You can add @samp{TCPOnly = yes} to host configuration files to force all VPN traffic to go over a TCP connection.
@end itemize
@item Got bad/bogus/unauthorized REQUEST from foo (1.2.3.4 port 12345)
@item The output of any command that fails to work as it should (like ping or traceroute).
@end itemize
+@c ==================================================================
+@node Controlling tinc
+@chapter Controlling tinc
+
+@cindex command line interface
+You can start, stop, control and inspect a running tincd through the tinc
+command. A quick example:
+
+@example
+tinc -n @var{netname} reload
+@end example
+
+@cindex shell
+If tinc is started without a command, it will act as a shell; it will display a
+prompt, and commands can be entered on the prompt. If tinc is compiled with
+libreadline, history and command completion are available on the prompt. One
+can also pipe a script containing commands through tinc. In that case, lines
+starting with a # symbol will be ignored.
+
+@menu
+* tinc runtime options::
+* tinc environment variables::
+* tinc commands::
+* tinc examples::
+* tinc top::
+@end menu
+
+
+@c ==================================================================
+@node tinc runtime options
+@section tinc runtime options
+
+@c from the manpage
+@table @option
+@item -c, --config=@var{path}
+Read configuration options from the directory @var{path}. The default is
+@file{@value{sysconfdir}/tinc/@var{netname}/}.
+
+@item -n, --net=@var{netname}
+Use configuration for net @var{netname}. @xref{Multiple networks}.
+
+@item --pidfile=@var{filename}
+Use the cookie from @var{filename} to authenticate with a running tinc daemon.
+If unspecified, the default is
+@file{@value{localstatedir}/run/tinc.@var{netname}.pid}.
+
+@item --force
+Force some commands to work despite warnings.
+
+@item --help
+Display a short reminder of runtime options and commands, then terminate.
+
+@item --version
+Output version information and exit.
+
+@end table
+
+@c ==================================================================
+@node tinc environment variables
+@section tinc environment variables
+
+@table @env
+@cindex NETNAME
+@item NETNAME
+If no netname is specified on the command line with the @option{-n} option,
+the value of this environment variable is used.
+@end table
+
+@c ==================================================================
+@node tinc commands
+@section tinc commands
+
+@c from the manpage
+@table @code
+
+@cindex init
+@item init [@var{name}]
+Create initial configuration files and RSA and Ed25519 keypairs with default length.
+If no @var{name} for this node is given, it will be asked for.
+
+@cindex get
+@item get @var{variable}
+Print the current value of configuration variable @var{variable}.
+If more than one variable with the same name exists,
+the value of each of them will be printed on a separate line.
+
+@cindex set
+@item set @var{variable} @var{value}
+Set configuration variable @var{variable} to the given @var{value}.
+All previously existing configuration variables with the same name are removed.
+To set a variable for a specific host, use the notation @var{host}.@var{variable}.
+
+@cindex add
+@item add @var{variable} @var{value}
+As above, but without removing any previously existing configuration variables.
+If the variable already exists with the given value, nothing happens.
+
+@cindex del
+@item del @var{variable} [@var{value}]
+Remove configuration variables with the same name and @var{value}.
+If no @var{value} is given, all configuration variables with the same name will be removed.
+
+@cindex edit
+@item edit @var{filename}
+Start an editor for the given configuration file.
+You do not need to specify the full path to the file.
+
+@cindex export
+@item export
+Export the host configuration file of the local node to standard output.
+
+@cindex export-all
+@item export-all
+Export all host configuration files to standard output.
+
+@cindex import
+@item import
+Import host configuration file(s) generated by the tinc export command from standard input.
+Already existing host configuration files are not overwritten unless the option --force is used.
+
+@cindex exchange
+@item exchange
+The same as export followed by import.
+
+@cindex exchange-all
+@item exchange-all
+The same as export-all followed by import.
+
+@cindex invite
+@item invite @var{name}
+Prepares an invitation for a new node with the given @var{name},
+and prints a short invitation URL that can be used with the join command.
+
+@cindex join
+@item join [@var{URL}]
+Join an existing VPN using an invitation URL created using the invite command.
+If no @var{URL} is given, it will be read from standard input.
+
+@cindex start
+@item start [tincd options]
+Start @samp{tincd}, optionally with the given extra options.
+
+@cindex stop
+@item stop
+Stop @samp{tincd}.
+
+@cindex restart
+@item restart [tincd options]
+Restart @samp{tincd}, optionally with the given extra options.
+
+@cindex reload
+@item reload
+Partially rereads configuration files. Connections to hosts whose host
+config files are removed are closed. New outgoing connections specified
+in @file{tinc.conf} will be made.
+
+@cindex pid
+@item pid
+Shows the PID of the currently running @samp{tincd}.
+
+@cindex generate-keys
+@item generate-keys [@var{bits}]
+Generate both RSA and Ed25519 keypairs (see below) and exit.
+tinc will ask where you want to store the files, but will default to the
+configuration directory (you can use the -c or -n option).
+
+@cindex generate-ed25519-keys
+@item generate-ed25519-keys
+Generate public/private Ed25519 keypair and exit.
+
+@cindex generate-rsa-keys
+@item generate-rsa-keys [@var{bits}]
+Generate public/private RSA keypair and exit. If @var{bits} is omitted, the
+default length will be 2048 bits. When saving keys to existing files, tinc
+will not delete the old keys; you have to remove them manually.
+
+@cindex dump
+@item dump [reachable] nodes
+Dump a list of all known nodes in the VPN.
+If the reachable keyword is used, only lists reachable nodes.
+
+@item dump edges
+Dump a list of all known connections in the VPN.
+
+@item dump subnets
+Dump a list of all known subnets in the VPN.
+
+@item dump connections
+Dump a list of all meta connections with ourself.
+
+@cindex graph
+@item dump graph | digraph
+Dump a graph of the VPN in dotty format.
+Nodes are colored according to their reachability:
+red nodes are unreachable, orange nodes are indirectly reachable, green nodes are directly reachable.
+Black nodes are either directly or indirectly reachable, but direct reachability has not been tried yet.
+
+@item dump invitations
+Dump a list of outstanding invitations.
+The filename of the invitation, as well as the name of the node that is being invited is shown for each invitation.
+
+@cindex info
+@item info @var{node} | @var{subnet} | @var{address}
+Show information about a particular @var{node}, @var{subnet} or @var{address}.
+If an @var{address} is given, any matching subnet will be shown.
+
+@cindex purge
+@item purge
+Purges all information remembered about unreachable nodes.
+
+@cindex debug
+@item debug @var{level}
+Sets debug level to @var{level}.
+
+@cindex log
+@item log [@var{level}]
+Capture log messages from a running tinc daemon.
+An optional debug level can be given that will be applied only for log messages sent to tinc.
+
+@cindex retry
+@item retry
+Forces tinc to try to connect to all uplinks immediately.
+Usually tinc attempts to do this itself,
+but increases the time it waits between the attempts each time it failed,
+and if tinc didn't succeed to connect to an uplink the first time after it started,
+it defaults to the maximum time of 15 minutes.
+
+@cindex disconnect
+@item disconnect @var{node}
+Closes the meta connection with the given @var{node}.
+
+@cindex top
+@item top
+If tinc is compiled with libcurses support, this will display live traffic statistics for all the known nodes,
+similar to the UNIX top command.
+See below for more information.
+
+@cindex pcap
+@item pcap
+Dump VPN traffic going through the local tinc node in pcap-savefile format to standard output,
+from where it can be redirected to a file or piped through a program that can parse it directly,
+such as tcpdump.
+
+@cindex network
+@item network [@var{netname}]
+If @var{netname} is given, switch to that network.
+Otherwise, display a list of all networks for which configuration files exist.
+
+@cindex fsck
+@item fsck
+This will check the configuration files for possible problems,
+such as unsafe file permissions, missing executable bit on script,
+unknown and obsolete configuration variables, wrong public and/or private keys, and so on.
+
+When problems are found, this will be printed on a line with WARNING or ERROR in front of it.
+Most problems must be corrected by the user itself, however in some cases (like file permissions and missing public keys),
+tinc will ask if it should fix the problem.
+
+@cindex sign
+@item sign [@var{filename}]
+Sign a file with the local node's private key.
+If no @var{filename} is given, the file is read from standard input.
+The signed file is written to standard output.
+
+@cindex verify
+@item verify @var{name} [@var{filename}]
+
+Check the signature of a file against a node's public key.
+The @var{name} of the node must be given,
+or can be "." to check against the local node's public key,
+or "*" to allow a signature from any node whose public key is known.
+If no @var{filename} is given, the file is read from standard input.
+If the verification is succesful, a copy of the input with the signature removed is written to standard output, and the exit code will be zero.
+If the verification failed, nothing will be written to standard output, and the exit code will be non-zero.
+
+@end table
+
+@c ==================================================================
+@node tinc examples
+@section tinc examples
+
+Examples of some commands:
+
+@example
+tinc -n vpn dump graph | circo -Txlib
+tinc -n vpn pcap | tcpdump -r -
+tinc -n vpn top
+@end example
+
+Examples of changing the configuration using tinc:
+
+@example
+tinc -n vpn init foo
+tinc -n vpn add Subnet 192.168.1.0/24
+tinc -n vpn add bar.Address bar.example.com
+tinc -n vpn add ConnectTo bar
+tinc -n vpn export | gpg --clearsign | mail -s "My config" vpnmaster@@example.com
+@end example
+
+@c ==================================================================
+@node tinc top
+@section tinc top
+
+@cindex top
+The top command connects to a running tinc daemon and repeatedly queries its per-node traffic counters.
+It displays a list of all the known nodes in the left-most column,
+and the amount of bytes and packets read from and sent to each node in the other columns.
+By default, the information is updated every second.
+The behaviour of the top command can be changed using the following keys:
+
+@table @key
+
+@item s
+Change the interval between updates.
+After pressing the @key{s} key, enter the desired interval in seconds, followed by enter.
+Fractional seconds are honored.
+Intervals lower than 0.1 seconds are not allowed.
+
+@item c
+Toggle between displaying current traffic rates (in packets and bytes per second)
+and cummulative traffic (total packets and bytes since the tinc daemon started).
+
+@item n
+Sort the list of nodes by name.
+
+@item i
+Sort the list of nodes by incoming amount of bytes.
+
+@item I
+Sort the list of nodes by incoming amount of packets.
+
+@item o
+Sort the list of nodes by outgoing amount of bytes.
+
+@item O
+Sort the list of nodes by outgoing amount of packets.
+
+@item t
+Sort the list of nodes by sum of incoming and outgoing amount of bytes.
+
+@item T
+Sort the list of nodes by sum of incoming and outgoing amount of packets.
+
+@item b
+Show amount of traffic in bytes.
+
+@item k
+Show amount of traffic in kilobytes.
+
+@item M
+Show amount of traffic in megabytes.
+
+@item G
+Show amount of traffic in gigabytes.
+
+@item q
+Quit.
+
+@end table
+
+
@c ==================================================================
@node Technical information
@chapter Technical information
there is no problem for the kernel to accept a packet.
However, if it is a `tap' device (this is the only available type on FreeBSD),
the destination MAC address must match that of the virtual network interface.
-If tinc is in it's default routing mode, ARP does not work, so the correct destination MAC
+If tinc is in it's default routing mode, ARP does not work, so the correct destination MAC
can not be known by the sending host.
Tinc solves this by letting the receiving end detect the MAC address of its own virtual network interface
and overwriting the destination MAC address of the received packet.
and to read and write requests by hand, provided that one
understands the numeric codes sent.
-The authentication scheme is described in @ref{Authentication protocol}. After a
+The authentication scheme is described in @ref{Security}. After a
successful authentication, the server and the client will exchange all the
information about other tinc daemons and subnets they know of, so that both
sides (and all the other tinc daemons behind them) have their information
------------------------------------------------------------------
REQ_KEY origin destination
| +--> name of the tinc daemon it wants the key from
- +----------> name of the daemon that wants the key
+ +----------> name of the daemon that wants the key
ANS_KEY origin destination 4ae0b0a82d6e0078 91 64 4
| | \______________/ | | +--> MAC length
@cindex PING
@cindex PONG
@example
-daemon message
+daemon message
------------------------------------------------------------------
-origin PING
-dest. PONG
+origin PING
+dest. PONG
------------------------------------------------------------------
@end example
@cindex SVPN
But in order to be ``immune'' to eavesdropping, you'll have to encrypt
-your data. Because tinc is a @emph{Secure} VPN (SVPN) daemon, it does
+your data. Because tinc is a @emph{Secure} VPN (SVPN) daemon, it does
exactly that: encrypt.
-Tinc by default uses blowfish encryption with 128 bit keys in CBC mode, 32 bit
-sequence numbers and 4 byte long message authentication codes to make sure
-eavesdroppers cannot get and cannot change any information at all from the
-packets they can intercept. The encryption algorithm and message authentication
-algorithm can be changed in the configuration. The length of the message
-authentication codes is also adjustable. The length of the key for the
-encryption algorithm is always the default length used by OpenSSL.
+However, encryption in itself does not prevent an attacker from modifying the encrypted data.
+Therefore, tinc also authenticates the data.
+Finally, tinc uses sequence numbers (which themselves are also authenticated) to prevent an attacker from replaying valid packets.
+
+Since version 1.1pre3, tinc has two protocols used to protect your data; the legacy protocol, and the new Simple Peer-to-Peer Security (SPTPS) protocol.
+The SPTPS protocol is designed to address some weaknesses in the legacy protocol.
+The new authentication protocol is used when two nodes connect to each other that both have the ExperimentalProtocol option set to yes,
+otherwise the legacy protocol will be used.
@menu
-* Authentication protocol::
+* Legacy authentication protocol::
+* Simple Peer-to-Peer Security::
* Encryption of network packets::
* Security issues::
@end menu
@c ==================================================================
-@node Authentication protocol
-@subsection Authentication protocol
+@node Legacy authentication protocol
+@subsection Legacy authentication protocol
-@cindex authentication
-A new scheme for authentication in tinc has been devised, which offers some
-improvements over the protocol used in 1.0pre2 and 1.0pre3. Explanation is
-below.
+@cindex legacy authentication protocol
@cindex ID
@cindex META_KEY
server <accepts connection>
-client ID client 12
- | +---> version
- +-------> name of tinc daemon
-
-server ID server 12
- | +---> version
- +-------> name of tinc daemon
-
-client META_KEY 5f0823a93e35b69e...7086ec7866ce582b
- \_________________________________/
- +-> RSAKEYLEN bits totally random string S1,
- encrypted with server's public RSA key
+client ID client 17.2
+ | | +-> minor protocol version
+ | +----> major protocol version
+ +--------> name of tinc daemon
+
+server ID server 17.2
+ | | +-> minor protocol version
+ | +----> major protocol version
+ +--------> name of tinc daemon
+
+client META_KEY 94 64 0 0 5f0823a93e35b69e...7086ec7866ce582b
+ | | | | \_________________________________/
+ | | | | +-> RSAKEYLEN bits totally random string S1,
+ | | | | encrypted with server's public RSA key
+ | | | +-> compression level
+ | | +---> MAC length
+ | +------> digest algorithm NID
+ +---------> cipher algorithm NID
+
+server META_KEY 94 64 0 0 6ab9c1640388f8f0...45d1a07f8a672630
+ | | | | \_________________________________/
+ | | | | +-> RSAKEYLEN bits totally random string S2,
+ | | | | encrypted with client's public RSA key
+ | | | +-> compression level
+ | | +---> MAC length
+ | +------> digest algorithm NID
+ +---------> cipher algorithm NID
+--------------------------------------------------------------------------
+@end example
-server META_KEY 6ab9c1640388f8f0...45d1a07f8a672630
- \_________________________________/
- +-> RSAKEYLEN bits totally random string S2,
- encrypted with client's public RSA key
+The protocol allows each side to specify encryption algorithms and parameters,
+but in practice they are always fixed, since older versions of tinc did not
+allow them to be different from the default values. The cipher is always
+Blowfish in OFB mode, the digest is SHA1, but the MAC length is zero and no
+compression is used.
From now on:
- - the client will symmetrically encrypt outgoing traffic using S1
- - the server will symmetrically encrypt outgoing traffic using S2
+@itemize
+@item the client will symmetrically encrypt outgoing traffic using S1
+@item the server will symmetrically encrypt outgoing traffic using S2
+@end itemize
+@example
+--------------------------------------------------------------------------
client CHALLENGE da02add1817c1920989ba6ae2a49cecbda0
\_________________________________/
+-> CHALLEN bits totally random string H1
client ACK 655 123 0
| | +-> options
- | +----> estimated weight
- +--------> listening port of client
+ | +----> estimated weight
+ +--------> listening port of client
server ACK 655 321 0
| | +-> options
- | +----> estimated weight
- +--------> listening port of server
+ | +----> estimated weight
+ +--------> listening port of server
--------------------------------------------------------------------------
@end example
-This new scheme has several improvements, both in efficiency and security.
-
-First of all, the server sends exactly the same kind of messages over the wire
-as the client. The previous versions of tinc first authenticated the client,
-and then the server. This scheme even allows both sides to send their messages
-simultaneously, there is no need to wait for the other to send something first.
-This means that any calculations that need to be done upon sending or receiving
-a message can also be done in parallel. This is especially important when doing
-RSA encryption/decryption. Given that these calculations are the main part of
-the CPU time spent for the authentication, speed is improved by a factor 2.
-
-Second, only one RSA encrypted message is sent instead of two. This reduces the
-amount of information attackers can see (and thus use for a cryptographic
-attack). It also improves speed by a factor two, making the total speedup a
-factor 4.
-
-Third, and most important:
-The symmetric cipher keys are exchanged first, the challenge is done
-afterwards. In the previous authentication scheme, because a man-in-the-middle
-could pass the challenge/chal_reply phase (by just copying the messages between
-the two real tinc daemons), but no information was exchanged that was really
-needed to read the rest of the messages, the challenge/chal_reply phase was of
-no real use. The man-in-the-middle was only stopped by the fact that only after
-the ACK messages were encrypted with the symmetric cipher. Potentially, it
-could even send it's own symmetric key to the server (if it knew the server's
-public key) and read some of the metadata the server would send it (it was
-impossible for the mitm to read actual network packets though). The new scheme
-however prevents this.
-
-This new scheme makes sure that first of all, symmetric keys are exchanged. The
-rest of the messages are then encrypted with the symmetric cipher. Then, each
-side can only read received messages if they have their private key. The
-challenge is there to let the other side know that the private key is really
-known, because a challenge reply can only be sent back if the challenge is
-decrypted correctly, and that can only be done with knowledge of the private
-key.
-
-Fourth: the first thing that is sent via the symmetric cipher encrypted
-connection is a totally random string, so that there is no known plaintext (for
-an attacker) in the beginning of the encrypted stream.
+This legacy authentication protocol has several weaknesses, pointed out by security export Peter Gutmann.
+First, data is encrypted with RSA without padding.
+Padding schemes are designed to prevent attacks when the size of the plaintext is not equal to the size of the RSA key.
+Tinc always encrypts random nonces that have the same size as the RSA key, so we do not believe this leads to a break of the security.
+There might be timing or other side-channel attacks against RSA encryption and decryption, tinc does not employ any protection against those.
+Furthermore, both sides send identical messages to each other, there is no distinction between server and client,
+which could make a MITM attack easier.
+However, no exploit is known in which a third party who is not already trusted by other nodes in the VPN could gain access.
+Finally, the RSA keys are used to directly encrypt the session keys, which means that if the RSA keys are compromised, it is possible to decrypt all previous VPN traffic.
+In other words, the legacy protocol does not provide perfect forward secrecy.
+
+@c ==================================================================
+@node Simple Peer-to-Peer Security
+@subsection Simple Peer-to-Peer Security
+@cindex SPTPS
+
+The SPTPS protocol is designed to address the weaknesses in the legacy protocol.
+SPTPS is based on TLS 1.2, but has been simplified: there is no support for exchanging public keys, and there is no cipher suite negotiation.
+Instead, SPTPS always uses a very strong cipher suite:
+peers authenticate each other using 521 bits ECC keys,
+Diffie-Hellman using ephemeral 521 bits ECC keys is used to provide perfect forward secrecy (PFS),
+AES-256-CTR is used for encryption, and HMAC-SHA-256 for message authentication.
+
+Similar to TLS, messages are split up in records.
+A complete logical record contains the following information:
+
+@itemize
+@item uint32_t seqno (network byte order)
+@item uint16_t length (network byte order)
+@item uint8_t type
+@item opaque data[length]
+@item opaque hmac[HMAC_SIZE] (HMAC over all preceding fields)
+@end itemize
+
+Depending on whether SPTPS records are sent via TCP or UDP, either the seqno or the length field is omitted on the wire
+(but they are still included in the calculation of the HMAC);
+for TCP packets are guaranteed to arrive in-order so we can infer the seqno, but packets can be split or merged, so we still need the length field to determine the boundaries between records;
+for UDP packets we know that there is exactly one record per packet, and we know the length of a packet, but packets can be dropped, duplicated and/or reordered, so we need to include the seqno.
+
+The type field is used to distinguish between application records or handshake records.
+Types 0 to 127 are application records, type 128 is a handshake record, and types 129 to 255 are reserved.
+
+Before the initial handshake, no fields are encrypted, and the HMAC field is not present.
+After the authentication handshake, the length (if present), type and data fields are encrypted, and the HMAC field is present.
+For UDP packets, the seqno field is not encrypted, as it is used to determine the value of the counter used for encryption.
+
+The authentication consists of an exchange of Key EXchange, SIGnature and ACKnowledge messages, transmitted using type 128 records.
+
+Overview:
+
+@example
+Initiator Responder
+---------------------
+KEX ->
+ <- KEX
+SIG ->
+ <- SIG
+
+...encrypt and HMAC using session keys from now on...
+
+App ->
+ <- App
+...
+ ...
+
+...key renegotiation starts here...
+
+KEX ->
+ <- KEX
+SIG ->
+ <- SIG
+ACK ->
+ <- ACK
+
+...encrypt and HMAC using new session keys from now on...
+
+App ->
+ <- App
+...
+ ...
+---------------------
+@end example
+
+Note that the responder does not need to wait before it receives the first KEX message,
+it can immediately send its own once it has accepted an incoming connection.
+
+Key EXchange message:
+
+@itemize
+@item uint8_t kex_version (always 0 in this version of SPTPS)
+@item opaque nonce[32] (random number)
+@item opaque ecdh_key[ECDH_SIZE]
+@end itemize
+
+SIGnature message:
+
+@itemize
+@item opaque ecdsa_signature[ECDSA_SIZE]
+@end itemize
+
+ACKnowledge message:
+
+@itemize
+@item empty (only sent after key renegotiation)
+@end itemize
+
+Remarks:
+@itemize
+@item At the start, both peers generate a random nonce and an Elliptic Curve public key and send it to the other in the KEX message.
+@item After receiving the other's KEX message, both KEX messages are concatenated (see below),
+ and the result is signed using ECDSA.
+ The result is sent to the other.
+@item After receiving the other's SIG message, the signature is verified.
+ If it is correct, the shared secret is calculated from the public keys exchanged in the KEX message using the Elliptic Curve Diffie-Helman algorithm.
+@item The shared secret key is expanded using a PRF.
+ Both nonces and the application specific label are also used as input for the PRF.
+@item An ACK message is sent only when doing key renegotiation, and is sent using the old encryption keys.
+@item The expanded key is used to key the encryption and HMAC algorithms.
+@end itemize
+
+The signature is calculated over this string:
+
+@itemize
+@item uint8_t initiator (0 = local peer, 1 = remote peer is initiator)
+@item opaque remote_kex_message[1 + 32 + ECDH_SIZE]
+@item opaque local_kex_message[1 + 32 + ECDH_SIZE]
+@item opaque label[label_length]
+@end itemize
+
+The PRF is calculated as follows:
+
+@itemize
+@item A HMAC using SHA512 is used, the shared secret is used as the key.
+@item For each block of 64 bytes, a HMAC is calculated. For block n: hmac[n] =
+ HMAC_SHA512(hmac[n - 1] + seed)
+@item For the first block (n = 1), hmac[0] is given by HMAC_SHA512(zeroes + seed),
+ where zeroes is a block of 64 zero bytes.
+@end itemize
+
+The seed is as follows:
+
+@itemize
+@item const char[13] "key expansion"
+@item opaque responder_nonce[32]
+@item opaque initiator_nonce[32]
+@item opaque label[label_length]
+@end itemize
+
+The expanded key is used as follows:
+
+@itemize
+@item opaque responder_cipher_key[CIPHER_KEYSIZE]
+@item opaque responder_digest_key[DIGEST_KEYSIZE]
+@item opaque initiator_cipher_key[CIPHER_KEYSIZE]
+@item opaque initiator_digest_key[DIGEST_KEYSIZE]
+@end itemize
+
+Where initiator_cipher_key is the key used by session initiator to encrypt
+messages sent to the responder.
+
+When using 256 bits Ed25519 keys, the AES-256-CTR cipher and HMAC-SHA-256 digest algorithm,
+the sizes are as follows:
+
+@example
+ECDH_SIZE: 32 (= 256/8)
+ECDSA_SIZE: 64 (= 2 * 256/8)
+CIPHER_KEYSIZE: 48 (= 256/8 + 128/8)
+DIGEST_KEYSIZE: 32 (= 256/8)
+@end example
+
+Note that the cipher key also includes the initial value for the counter.
@c ==================================================================
@node Encryption of network packets
A data packet can only be sent if the encryption key is known to both
parties, and the connection is activated. If the encryption key is not
known, a request is sent to the destination using the meta connection
-to retrieve it. The packet is stored in a queue while waiting for the
-key to arrive.
+to retrieve it.
@cindex UDP
-The UDP packet containing the network packet from the VPN has the following layout:
+The UDP packets can be either encrypted with the legacy protocol or with SPTPS.
+In case of the legacy protocol, the UDP packet containing the network packet from the VPN has the following layout:
@example
... | IP header | UDP header | seqno | VPN packet | MAC | UDP trailer
Encrypted with symmetric cipher
@end example
+
+
+
So, the entire VPN packet is encrypted using a symmetric cipher, including a 32 bits
sequence number that is added in front of the actual VPN packet, to act as a unique
IV for each packet and to prevent replay attacks. A message authentication code
-is added to the UDP packet to prevent alteration of packets. By default the
-first 4 bytes of the digest are used for this, but this can be changed using
-the MACLength configuration variable.
+is added to the UDP packet to prevent alteration of packets.
+Tinc by default encrypts network packets using Blowfish with 128 bit keys in CBC mode
+and uses 4 byte long message authentication codes to make sure
+eavesdroppers cannot get and cannot change any information at all from the
+packets they can intercept. The encryption algorithm and message authentication
+algorithm can be changed in the configuration. The length of the message
+authentication codes is also adjustable. The length of the key for the
+encryption algorithm is always the default length used by LibreSSL/OpenSSL.
+
+The SPTPS protocol is described in @ref{Simple Peer-to-Peer Security}.
+For comparison, this is how SPTPS UDP packets look:
+
+@example
+... | IP header | UDP header | seqno | type | VPN packet | MAC | UDP trailer
+ \__________________/\_____/
+ | |
+ V +---> digest algorithm
+ Encrypted with symmetric cipher
+@end example
+
+The difference is that the seqno is not encrypted, since the encryption cipher is used in CTR mode,
+and therefore the seqno must be known before the packet can be decrypted.
+Furthermore, the MAC is never truncated.
+The SPTPS protocol always uses the AES-256-CTR cipher and HMAC-SHA-256 digest,
+this cannot be changed.
+
@c ==================================================================
@node Security issues
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
+tinc as secure as possible. The current version uses the LibreSSL or OpenSSL library and
uses strong authentication with RSA keys.
On the 29th of December 2001, Jerome Etienne posted a security analysis of tinc
1.0.1. He argues that the 32 bit sequence number used by tinc is not a good IV,
that tinc's default length of 4 bytes for the MAC is too short, and he doesn't
like tinc's use of RSA during authentication. We do not know of a security hole
-in this version of tinc, but tinc's security is not as strong as TLS or IPsec.
-We will address these issues in tinc 2.0.
+in the legacy protocol of tinc, but it is not as strong as TLS or IPsec.
+
+This version of tinc comes with an improved protocol, called Simple Peer-to-Peer Security,
+which aims to be as strong as TLS with one of the strongest cipher suites.
Cryptography is a hard thing to get right. We cannot make any
guarantees. Time, review and feedback are the only things that can
@section Contact information
@cindex website
-Tinc's website is at @url{http://www.tinc-vpn.org/},
+Tinc's website is at @url{https://www.tinc-vpn.org/},
this server is located in the Netherlands.
@cindex IRC
We have an IRC channel on the FreeNode and OFTC IRC networks. Connect to
-@uref{http://www.freenode.net/, irc.freenode.net}
+@uref{https://freenode.net/, irc.freenode.net}
or
-@uref{http://www.oftc.net/, irc.oftc.net}
+@uref{https://www.oftc.net/, irc.oftc.net}
and join channel #tinc.
projects / tinc / blobdiff