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/*
Copyright (c) 2012-2014, Matthias Schiffer <mschiffer@universe-factory.net>
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
\file
ec25519-fhmqvc protocol: handshake handling
*/
#pragma once
#include "ec25519_fhmqvc.h"
/**
An ephemeral keypair used for the handshake protocol
When a keypair's \e preferred_till has timed out, a new keypair
will be generated.
*/
typedef struct handshake_key {
/**
With each keypair, the serial number gets incremented.
By saving the serial number for established sessions,
it can be ensured that no two sessions with the same peer are established
with the same keypair
*/
uint64_t serial;
fastd_timeout_t preferred_till; /**< Specifies how long this keypair will be used for new handshakes */
fastd_timeout_t valid_till; /**< Specifies how long handshakes using this keypair will be answered */
keypair_t key; /**< The actual keypair */
} handshake_key_t;
/**
The protocol-specific global state
There are up to two keys valid at the same time.
*/
struct fastd_protocol_state {
handshake_key_t prev_handshake_key; /**< The previously generated handshake keypair */
handshake_key_t handshake_key; /**< The newest handshake keypair */
};
/** Checks if a handshake keypair is currently valid */
static inline bool is_handshake_key_valid(const handshake_key_t *handshake_key) {
return !fastd_timed_out(handshake_key->valid_till);
}
/** Checks if a handshake keypair is currently peferred */
static inline bool is_handshake_key_preferred(const handshake_key_t *handshake_key) {
return !fastd_timed_out(handshake_key->preferred_till);
}
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