From fc8c8d82f05911836208cc9169e103d5578ffd70 Mon Sep 17 00:00:00 2001 From: Matthias Schiffer Date: Mon, 28 Oct 2013 18:27:10 +0100 Subject: Unify duplicate code in xsalsa20-poly1305 and aes128-gcm methods --- src/methods/common.h | 86 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 86 insertions(+) create mode 100644 src/methods/common.h (limited to 'src/methods/common.h') diff --git a/src/methods/common.h b/src/methods/common.h new file mode 100644 index 0000000..0337265 --- /dev/null +++ b/src/methods/common.h @@ -0,0 +1,86 @@ +/* + Copyright (c) 2012-2013, Matthias Schiffer + 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. +*/ + + +#ifndef _FASTD_METHODS_COMMON_H_ +#define _FASTD_METHODS_COMMON_H_ + +#include + + +#define COMMON_NONCEBYTES 7 + + +typedef struct fastd_method_common { + struct timespec valid_till; + struct timespec refresh_after; + + uint8_t send_nonce[COMMON_NONCEBYTES]; + uint8_t receive_nonce[COMMON_NONCEBYTES]; + + struct timespec receive_last; + uint64_t receive_reorder_seen; +} fastd_method_common_t; + + +void fastd_method_common_init(fastd_context_t *ctx, fastd_method_common_t *session, bool initiator); +bool fastd_method_is_nonce_valid(fastd_context_t *ctx, const fastd_method_common_t *session, const uint8_t nonce[COMMON_NONCEBYTES], int64_t *age); +bool fastd_method_reorder_check(fastd_context_t *ctx, fastd_peer_t *peer, fastd_method_common_t *session, const uint8_t nonce[COMMON_NONCEBYTES], int64_t age); + + +static inline bool fastd_method_session_common_is_valid(fastd_context_t *ctx, const fastd_method_common_t *session) { + return (timespec_after(&session->valid_till, &ctx->now)); +} + +static inline bool fastd_method_session_common_is_initiator(const fastd_method_common_t *session) { + return (session->send_nonce[0] & 1); +} + +static inline bool fastd_method_session_common_want_refresh(fastd_context_t *ctx, const fastd_method_common_t *session) { + return timespec_after(&ctx->now, &session->refresh_after); +} + +static inline void fastd_method_session_common_superseded(fastd_context_t *ctx, fastd_method_common_t *session) { + struct timespec valid_max = ctx->now; + valid_max.tv_sec += ctx->conf->key_valid_old; + + if (timespec_after(&session->valid_till, &valid_max)) + session->valid_till = valid_max; +} + +static inline void fastd_method_increment_nonce(fastd_method_common_t *session) { + session->send_nonce[0] += 2; + + if (session->send_nonce[0] == 0 || session->send_nonce[0] == 1) { + int i; + for (i = 1; i < COMMON_NONCEBYTES; i++) { + session->send_nonce[i]++; + if (session->send_nonce[i] != 0) + break; + } + } +} + +#endif /* _FASTD_METHODS_COMMON_H_ */ -- cgit v1.2.3