OpenVPN currently uses its own (based on TLS 1.0) key derivation
mechanism to generate the 256 bytes key data in key2 struct that
are then used used to generate encryption/hmac/iv vectors. While
this mechanism is still secure, it is not state of the art.
Instead of modernising our own approach, this commit implements
key derivation using the Keying Material Exporters API introduced
by RFC 5705.
We also use an opportunistic approach of negotiating the use of
EKM (exported key material) through an IV_PROTO flag and prefer
EKM to our own PRF if both client and server support it. The
use of EKM is pushed to the client as part of NCP as
key-derivation tls-ekm.
We still exchange the random data (112 bytes from client to server
and 64 byte from server to client) for the OpenVPN PRF but
do not use it. Removing that exchange would break the handshake
and make a key-method 3 or similar necessary.
As a side effect, this makes a little bit easier to have a FIPS compatible
version of OpenVPN since we do not rely on calling MD5 anymore.
Side note: this commit breaks the (not yet merged) WolfSSL support as it
claims to support EKM in the OpenSSL compat API but always returns an error
if you try to use it.
Patch v2: rebase/change to V2 of EKM refactoring
Patch v3: add Changes.rst
Patch v4: Rebase on master.
Patch v5: Refuse internal label to be used with --keying-material-exporter,
polishing/fixes suggested by Steffan integrated
Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Steffan Karger <steffan.karger@foxcrypto.com>
Message-Id: <20201009115453.4279-1-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg21187.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
Key-method 1 is only needed to talk to pre OpenVPN 2.0 clients.
Patch V2: Fix style. Make V1 op codes illegal, remove all code handling
v1 op codes and give a good warning message if we encounter
them in the legal op codes pre-check.
Patch V3: Add a bit more comments in the existing methods.
Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: David Sommerseth <davids@openvpn.net>
Message-Id: <20200721100128.9850-1-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg20516.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
The autumn of 2017, OpenVPN Technologies, Inc changed name to just
OpenVPN Inc. Otherwise, extend the copyright to cover 2018 as well.
With the exception of the company name change, all changes have been
performed by the dev-tools/update-copyright.sh script.
Signed-off-by: David Sommerseth <davids@openvpn.net>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20180131140314.11103-1-davids@openvpn.net>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg16418.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
There were references in our documentation to the now deprecated PolarSSL
library, which have changed name upstream to mbed TLS.
In addition, where appropriate, the documentation now considers only
mbed TLS 2.0 and newer. This is in accordance with the requirements
./configure sets.
[DS: On-the-fly change - Updated Makefile.am to use README.mbedtls
instead of README.polarssl. This ensures make dist and buildbots
won't explode]
Signed-off-by: David Sommerseth <davids@openvpn.net>
Acked-by: Steffan Karger <steffan.karger@fox-it.com>
Message-Id: <20170822114715.14225-1-davids@openvpn.net>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg15309.html
Signed-off-by: David Sommerseth <davids@openvpn.net>
The COPYRIGHT.GPL file was slightly out-of-sync with the last GPLv2
license from Free Software Foundation, Inc.
The changes are primarily a new address, which required touching almost
all the project files.
Except of that, it is just minor adjustments to formatting, removal of
form-feed characters and referencing "GNU Lesser General Public License"
instead of "GNU Library General Public License".
Signed-off-by: David Sommerseth <davids@openvpn.net>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20170329093648.10156-1-davids@openvpn.net>
URL: https://www.mail-archive.com/search?l=mid&q=20170329093648.10156-1-davids@openvpn.net
Signed-off-by: Gert Doering <gert@greenie.muc.de>
