Data channel packet ids (in the formats that OpenVPN 3.x supports)
are plain 32 or 64 bit ids while control channel is a 32 bit time + 32
bit counter id. Seperate these more clearly and let CBC mode use the
same Packet ID implementation that AEAD mode uses.
Also add more unit tests related to data channel tests packets by
adapting the control channel test where applicable and add a few more
related to packet id wrapping
Signed-off-by: Arne Schwabe <arne@openvpn.net>
The psid cookie defense is designed to thwart resource exhaustion and
amplification attacks wherein a malicious client sends the server a
flood of CONTROL_HARD_RESET_CLIENT_V2 packets with spooofed source
addresses. This patch allows the server to defer client tracking
state creation until the client responds to the server's
CONTROL_HARD_RESET_SERVER_V2 message.
Signed-off-by: Mark Deric <jmark@openvpn.net>
This is the result after running 'clang-format -i' on all C++ files and
headers, with the defined formatting rules in .clang-format.
Only the openvpn/common/unicode-impl.hpp has been excluded, as that is
mostly a copy of an external project.
Signed-off-by: David Sommerseth <davids@openvpn.net>
This commit removes the ability to pass down the windows sizes for ack
windows down from the configuration. This capability was never used and
instead the receive and send window were both hardcoded at 4. Also
change the receive window to 12 and the send window to 6 like
OpenVPN 2.6 does.
Also to improve control channel reliability, resend previous ACKs in MRU
fashion if there is still room for them in a control channel packet.
This patch is based on a patch was written
by Charlie Vigue <charlie.vigue@openvpn.net>.
Signed-off-by: Arne Schwabe <arne@openvpn.net>
Triple DES, and other 64-bit block-size ciphers vulnerable
to "Sweet32" birthday attack (CVE-2016-6329). Limit such
cipher keys to no more than 64 MB of data
encrypted/decrypted. While our overall goal is to limit
data-limited keys to 64 MB, we trigger a renegotiation
at 48 MB to compensate for possible delays in renegotiation
and rollover to the new key.
This client-side implementation extends data limit
protection to the entire session, even when the server
doesn't implement data limits.
This capability is advertised to servers via the a
peer info setting:
IV_BS64DL=1
meaning "Block-Size 64-bit Data Limit". The "1" indicates
the implementation version.
The implementation currently has some limitations:
* Keys are renegotiated at a maximum rate of once per
5 seconds to reduce the likelihood of loss of
synchronization between peers.
* The maximum renegotiation rate may be further extended
if the peer delays rollover from the old to new key
after renegotiation.
Added N_KEY_LIMIT_RENEG stats counter to count the number
of data-limit-triggered renegotiations.
Added new stats counter KEY_STATE_ERROR which roughly
corresponds to the OpenVPN 2.x error "TLS Error:
local/remote TLS keys are out of sync".
Prevously, the TLS ack/retransmit timeout was hardcoded to
2 seconds. Now we lower the default to 1 second and make
it variable using the (pushable) "tls-timeout" directive.
Additionally, the tls-timeout directive can be specified
in milliseconds instead of seconds by using the
"tls-timeout-ms" form of the directive.
Made the "become primary" time duration configurable via
the (pushable) "become-primary" directive which accepts
a number-of-seconds parameter. become-primary indicates
the time delay between renegotiation and rollover to the
new key for encryption/transmission. become-primary
defaults to the handshake-window which in turn defaults
to 60 seconds.
Incremented core version to 3.0.20.
objects by simulating an unreliable packet stream.
Modified packet_id code so that current time (now) is passed
via function calls rather than accessed as a global.
Added integer random number support via boost::random.
