This adds support for parsing DEFAULT in data-ciphers, the idea is that people
can modify the default without repeating the default ciphers.
In the past we have seem that people will use data-ciphers BF-CBC or
data-ciphers AES-128-CBC when getting the warning that the cipher is not
supported by the server. This commit aims to provide a better way for
these situation as we still want people to rely on default cipher selection
from OpenVPN when possible.
Change-Id: Ia1c5209022d3ab4c0dac6438c41891c7d059f812
Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Frank Lichtenheld <frank@lichtenheld.com>
Message-Id: <20241227124632.110920-1-frank@lichtenheld.com>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg30245.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
We can't disable compression support on receive because
that would break too many configurations out there. But
we can remove the support for compressing outgoing traffic,
it was disabled by default anyway.
Makes "--allow-compression yes" an alias for
"--allow-compression asym" and removes all resulting dead code.
Change-Id: I402ba016b75cfcfec4fc8b2b01cc4eca7e2bcc60
Signed-off-by: Frank Lichtenheld <frank@lichtenheld.com>
Acked-by: Arne Schwabe <arne-openvpn@rfc2549.org>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20241108173851.436-1-gert@greenie.muc.de>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg29718.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
We now warn a user if the TLS 1.0 PRF is not supported by the cryptographic
library of the system. Also add the option --force-tls-key-material-export
that automatically rejects clients that do not support TLS Keying Material
Export and automatically enable it when TLS 1.0 PRF support is not available.
Change-Id: I04f8c7c413e7cb62c726262feee6ca89c7e86c70
Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20240104140214.32196-1-gert@greenie.muc.de>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg27924.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
OpenVPN 2.6 already warned about this feature being removed. OpenVPN
2.7 will with this change no longer accept these configurations without
having a --allow-deprecated-insecure-static-crypto added to the command
line or the configuration itself. This will serve as a last and final
warning for people who missed the warning message in OpenVPN 2.6.
This commit also removes the documentation for --secret and the static key
mode.
Change-Id: I4f29953b91cf8e8daf2c9503da44073ad96d0ff5
Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Frank Lichtenheld <frank@lichtenheld.com>
Message-Id: <20231009105832.34762-1-frank@lichtenheld.com>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg27194.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
This changes the "no" setting of allow-compression to also refuse framing
if DCO is active. This is important for our DCO implementations as these
do not implement framing.
This behaviour surfaced when a commercial VPN provider was pushing
"comp-lzo no" to a client with DCO. While we are technically at fault here
for announcing comp-lzo no support by announcing IV_LZO_STUB=1, the
VPN provider continues to push "comp-lzo no" even in absense of that
flag.
As the new default we default to 'allow-compression no' if DCO is
enabled and to 'allow-compression stub' otherwise.
This will now also bail out if the server pushes a compression setting that
we do not support as mismatching compression is almost never a working
connection. In the case of lz4-v2 and lzo-v2 you might have a connection
that works mostly but some packets will be dropped since they compressed
which is not desirable either since it becomes very hard to debug.
Patch v2: bail out if server pushes an unsupported method. Also include this
bail out logic when OpenVPN is compiled without compression support.
Patch v3: always parse all compression option and move logic to check method
Patch v4: fix for not setting correct default for non-dco
Change-Id: Ibd0c77af24e2214b3055d585dc23a4b06dccd414
Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20230324100640.1340535-1-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg26509.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
- Fix various formatting inconsistencies
- Remove outdated (as of 2.6) information from
--data-ciphers and instead add a link to
cipher negotiation chapter.
- Some drive-by fixes in related code comments
and log messages as I was reading them.
Signed-off-by: Frank Lichtenheld <frank@lichtenheld.com>
Acked-by: Arne Schwabe <arne@rfc2549.org>
Message-Id: <20220628080814.745-1-frank@lichtenheld.com>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg24575.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
Remove --keysize from the manual page and also remove mentioning
variable key size in output of ciphers as there is no longer a way to
change the keysize.
Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20211201180727.2496903-4-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg23275.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
This allows to use the same configuration multiple platforms/ssl libraries
and include optional algorithms that are not available on all platforms
For example "AES-256-GCM:AES-128-GCM:?CHACHA20-POLY1305" can be used to
emulate the default behaviour of OpenVPN 2.6.
Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20211201180727.2496903-1-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg23279.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
The bullet points are not proeprly indented and they trigger
the following error/warning:
rst2man.py openvpn.8.rst > openvpn.8
man-sections/protocol-options.rst:62: (ERROR/3) Unexpected indentation.
man-sections/protocol-options.rst:67: (WARNING/2) Block quote ends without
a blank line; unexpected unindent.
rst2man.py openvpn-examples.5.rst > openvpn-examples.5
rst2html.py openvpn.8.rst > openvpn.8.html
man-sections/protocol-options.rst:62: (ERROR/3) Unexpected indentation.
man-sections/protocol-options.rst:67: (WARNING/2) Block quote ends without
a blank line; unexpected unindent.
Fix indentation and add white lines as expected.
Signed-off-by: Antonio Quartulli <a@unstable.cc>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20210921121519.18912-1-a@unstable.cc>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg22867.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
The --cipher option has been there since a while, but it became more and
more confusing since the introduction of NCP (data cipher negotiation).
The fallback cipher can now be specified via --data-cipher-fallback,
while the list of accepted ciphers is specified via --data-ciphers.
--cipher can still be used for compatibility reasons, but won't affect
the cipher negotiation.
Adjust manpage to make clear that using --cipher in today's config really
is a thing from the past, and --data-ciphers should be used instead.
Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Signed-off-by: Antonio Quartulli <a@unstable.cc>
Acked-by: Arne Schwabe <arne@rfc2549.org>
Message-Id: <20210904095629.6273-5-a@unstable.cc>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg22799.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
Most TLS 1.3 libraries inlcude the Chacha20-Poly1305 based cipher suite
beside the AES-GCM based ones int he list of default ciphers suites.
Chacha20-Poly1305 is accepted as good alternative AEAD algorithm to the
AES-GCM algorithm by crypto community.
Follow this and include Chacha20-Poly1305 by default in data-ciphers
when available. This makes picking Chacha20-Poly1305 easier as it only
requires to change server (by changing priority) or client side (removing
AES-GCM from data-ciphers) to change to Chacha20-Poly1305.
Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Antonio Quartulli <antonio@openvpn.net>
Message-Id: <20210818213354.687736-2-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg22745.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
A code string terminating character (`) is missing, thus leading to the
following warning:
man-sections/protocol-options.rst:99: (WARNING/2) Inline interpreted text
or phrase reference start-string without end-string.
Add missing char at the end of the code word.
Cc: David Sommerseth <davids@openvpn.net>
Signed-off-by: Antonio Quartulli <a@unstable.cc>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20210827145656.21646-1-a@unstable.cc>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg22779.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
NCP has proven to be stable and apart from the one VPN Provider doing
hacky things with homebrewed NCP we have not had any reports about
ncp-disable being required. Remove ncp-disable to simplify code paths.
Note: This patch breaks client without --pull. The follow up patch
for P2P NCP will restore that. But to avoid all the NCP/non-NCP special
cases to be implemented in P2P. P2P will directly switch from always
non-NCP to always NCP.
Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Antonio Quartulli <antonio@openvpn.net>
Message-Id: <20210520151148.2565578-8-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg22418.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
The non-TLS mode is a relict from OpenVPN 1.x or 2.0. When TLS mode was
introduced the advantages of TLS over non-TLS were small but TLS mode
evolved to include a lot more features (NCP, multipeer, AEAD ciphers to
name a few).
Today VPN setups that use --secret are mainly used because this mode is
easier to setup and does not require setting up a PKI. This shortcoming
of TLS mode should be addressed now with the peer-fingerprint option.
The primary reason to deprecate --secret is that it is not secure enough
anymore for modern environments. This mode uses a fixed pre-shared key and
no session keys. Thus, no forward secrecy is possible, which means that
any captured VPN traffic can be decrypted later should the --secret key
get into the wrong hands. The cryptography overall used here was okay
when --secret was introduced but is not acceptable by today's standard
anymore.
Finally, modern hardware-accelerated crypto modes like AES-GCM can only
be used in TLS mode (due to IV requirements).
Patch V2: Improve commit message
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20210328090530.10653-1-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg21868.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
This option allow migration to a non compression server config while
still retraining compatibility with client that have a compression
setting in their config.
For existing setups that used to have comp-lzo no or another
compression setting in their configs it is a difficult to migrate to
a setup without compression without replacing all client configs at
once especially if OpenVPN 2.3 or earlier clients are in the mix that
do not support pushing stub-v2. Even with OpenVPN 2.4 and later clients
that support pushing this is not a satisfying solution as the clients
log occ mismatches and the "push stub-v2" needs to be in the server
config "forever".
If the new migrate option to compress is set and a client is detected
that indicates that compression is used (via OCC), the server will
automatically add ``--push compress stub-v2`` to the client specific
configuration if stub-v2 is supported by the client and otherwise
switch to ``comp-lzo no`` and add ``--push comp-lzo`` to the client
specific configuration.
Patch v2: better commit message/man page, add USE_COMP ifdefs, various
style fixes
Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Antonio Quartulli <antonio@openvpn.net>
Message-Id: <20210324220853.31246-1-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg21801.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
Most of the new compress but not v2 version do use swap operation. For
'compress lzo' the swap option is not used for backwards compatibility.
For lz4 the swap option is also not a problem since there is no version
without swap. Unfortunately, compress introduced a second stub format
with swap, contrary to the one in 'comp-lzo no' that does not use swap.
Document this weirdness to let not others fall into this trap.
v2: redo patch for rst man pages
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20200811110248.3396-1-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg20708.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
This reworks the NCP logic to be more strict about what is
considered an acceptable result of an NCP negotiation. It also
allows us to finally drop support for BF-CBC as default cipher.
All new behaviour is currently limited to server/client
mode with pull enabled. P2p mode without pull does not change.
New Server behaviour:
- when a client announces its supported ciphers through either
OCC or IV_CIPHER/IV_NCP we reject the client with a
AUTH_FAILED message if we have no common cipher.
- When a client does not announce any cipher in either
OCC or NCP we reject it unless data-ciphers-fallback is
specified in either ccd/ or config.
New client behaviour:
- When no cipher is pushed (or a cipher we refused to support)
and we also cannot support the server's cipher announced in
OCC we fail the connection and log why
- If there is no cipher in OCC but data-ciphers-fallback is
specified we will use the fallback cipher instead of failing the
connection
Both client and server behaviour:
- We only announce --cipher xyz in occ if we are willing
to support that cipher (always announce the cipher if
NCP is disabled or not in --client mode)
It means that we only announce the fallback-cipher if
it is also contained in --data-ciphers
Compatibility behaviour:
In 2.5 both client and server will use a --cipher xyz present
in the config to automatically set --data-ciphers-fallback xyz
and also append this cipher to the end of data-ciphers.
We log a warning about this and point to --data-ciphers and
--data-ciphers-fallback This also happens if the configuration
contains an explicit --cipher BF-CBC.
If --cipher is not set, we only warn that previous versions
allowed BF-CBC and point out how to re-enable BF-CBC. This will
break configs where someone connects a 2.3 client (or older)
to a 2.5 server AND has no explicit --cipher setting in the
server config. We still do it, because at some point we need
to drop the BF-CBC default - and affected users already had the
scary SWEET32 warning in their logs for a long time.
In short: If --cipher is explicitly set then 2.5 will work the
same as 2.4 did. When --cipher is not set, BF-CBC support is
dropped and we warn about it.
Examples how breaking the default BF-CBC will be logged:
Client side:
- Client connecting to server that does not push cipher but
has --cipher in OCC
OPTIONS ERROR: failed to negotiate cipher with server. Add the
server's cipher ('BF-CBC') to --data-ciphers (currently
'AES-256-GCM:AES-128-CBC') if you want to connect to this server.
- Client connecting to a server that does not support OCC:
OPTIONS ERROR: failed to negotiate cipher with server. Configure
--data-ciphers-fallback if you want connect to this server.
Server Side:
- Server has a client only supporting BF-CBC connecting:
styx/IP PUSH: No common cipher between server and client. Server
data-ciphers: 'CHACHA20-POLY1305:AES-128-GCM:AES-256-GCM:AES-256-CBC:AES-128-CBC', client supports cipher 'BF-CBC'.
- Client without OCC:
styx/IP PUSH:No NCP or OCC cipher data received from peer.
styx/IP Use --data-ciphers-fallback with the cipher the client is using
if you want to allow the client to connect
In all cases the client is rejected with this message:
AUTH: Received control message: AUTH_FAILED,Data channel cipher
negotiation failed (no shared cipher)
Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Patch V2: rename fallback-cipher to data-ciphers-fallback
add all corrections from Steffan
Ignore occ cipher for clients sending IV_CIPHERS
move client side ncp in its own function
do not print INSECURE cipher warning if BF-CBC is not allowed
Patch V3: fix minor style, add null check when client sends no peerinfo at
all
Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20200809141922.7853-1-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg20656.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
The change in name signals that data-ciphers is the preferred way to
configure data channel (and not --cipher). The data prefix is chosen
to avoid ambiguity and make it distinct from tls-cipher for the TLS
ciphers.
Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Steffan Karger <steffan.karger@foxcrypto.com>
Message-Id: <20200717134739.21168-8-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg20444.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
Commit c67e93b25208be2 updated the man page in reagrds to new
compression options and improving existing compression options. This
adopts those changes into the .rst format.
Signed-off-by: David Sommerseth <davids@openvpn.net>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20200716225338.611-7-davids@openvpn.net>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg20414.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
Due to the VORACLE attack vector, compression in general is deprecated.
Make this clear in the man page.
Also remove an incorrect statement claiming --compress lzo is compatible
with --comp-lzo. It is not, as --compress lzo uses a different
compression framing than --comp-lzo.
Signed-off-by: David Sommerseth <davids@openvpn.net>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20200716225338.611-6-davids@openvpn.net>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg20417.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
To avoid keeping around a full-size openvpn.rst file which is never
needed but will take space in the repo forever, patches 01...04
of the big documentation overhaul projects were squashed togehter,
keeping the individual commit logs and URL references below.
Signed-off-by: Gert Doering <gert@greenie.muc.de>
* This is a combination of 4 commits.
* This is the 1st commit message:
doc/man: Add an .rst formatted version of the man page
This is the first step to move away from a manually editing g/nroff
encoded man page.
Some modifications was needed to ensure formatting was consistent and
rendered reasonably okay in GitHub and that the generated man page
(using rst2man) is looking as a proper man page. Unsupported options
has also been moved into its own section. HTML rendering directly
using rst2html has also been used to validate the conversion.
The rst2man and rst2html utilities comes from the python-docutils
project: https://docutils.sourceforge.io/
Signed-off-by: David Sommerseth <davids@openvpn.net>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20200716225338.611-2-davids@openvpn.net>
URL: https://sourceforge.net/p/openvpn/mailman/message/37063370/
Signed-off-by: Gert Doering <gert@greenie.muc.de>
* This is the commit message #2:
doc/man: Replace old man page with generated man page
The doc/openvpn.8 and doc/openvpn.8.html files are now being removed
from the git tree, as it will be generated from the doc/openvpn.8.rst
file using python-docutils.
An additional dist-hook is added so these files are generated
automatically when source tarballs are generated for releases. This
means users compiling directly from the source tarball will not need
python-docutils installed.
Signed-off-by: David Sommerseth <davids@openvpn.net>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20200716225338.611-3-davids@openvpn.net>
URL: https://sourceforge.net/p/openvpn/mailman/message/37063373/
Signed-off-by: Gert Doering <gert@greenie.muc.de>
* This is the commit message #3:
doc/man: Split up and reorganize main man page
The openvpn.8.rst file is quite long and hard to edit, as it covers
several hundred options. Some options were even documented multiple
places. The example has also received some attention, cleaning up
old and outdated infomration.
In this commit the main man page is split up into multiple sections
and options are sorted into each of the corresponding section.
Inside each category, each option is for now sorted alphabetically.
The main openvpn.8.rst file is currently kept unchanged and will be
handled in the next commit.
Many language improvements contributed by Richard Bonhomme has also
been incorproated.
Signed-off-by: David Sommerseth <davids@openvpn.net>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20200716225338.611-4-davids@openvpn.net>
URL: https://sourceforge.net/p/openvpn/mailman/message/37063376/
Signed-off-by: Gert Doering <gert@greenie.muc.de>
* This is the commit message #4:
doc/man: Complete openvpn.8.rst splitting
This rebuilds the openvpn.8.rst content by using the text which was
split out in the previous commit by using RST ..include statements.
Signed-off-by: David Sommerseth <davids@openvpn.net>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20200716225338.611-5-davids@openvpn.net>
URL: https://sourceforge.net/p/openvpn/mailman/message/37063377/
Signed-off-by: Gert Doering <gert@greenie.muc.de>
