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authorMatthias Schiffer <mschiffer@universe-factory.net>2013-10-28 16:59:42 +0100
committerMatthias Schiffer <mschiffer@universe-factory.net>2013-10-28 16:59:42 +0100
commit095ca93d81cfae0fcb137919231810577c556404 (patch)
treea5ee059d61dd5c0483657105fb2f5400350f3150 /src/method_xsalsa20_poly1305.c
parent5f6177e00fe4c56ece2cabdd61b772ed040c6e19 (diff)
downloadfastd-095ca93d81cfae0fcb137919231810577c556404.tar
fastd-095ca93d81cfae0fcb137919231810577c556404.zip
Organize method and protocol source files into distinct source directories
Diffstat (limited to 'src/method_xsalsa20_poly1305.c')
-rw-r--r--src/method_xsalsa20_poly1305.c247
1 files changed, 0 insertions, 247 deletions
diff --git a/src/method_xsalsa20_poly1305.c b/src/method_xsalsa20_poly1305.c
deleted file mode 100644
index 395f322..0000000
--- a/src/method_xsalsa20_poly1305.c
+++ /dev/null
@@ -1,247 +0,0 @@
-/*
- Copyright (c) 2012-2013, 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.
-*/
-
-
-#include "fastd.h"
-#include <crypto_secretbox_xsalsa20poly1305.h>
-
-
-#define NONCEBYTES 7
-
-
-struct fastd_method_session_state {
- struct timespec valid_till;
- struct timespec refresh_after;
-
- uint8_t key[crypto_secretbox_xsalsa20poly1305_KEYBYTES];
-
- uint8_t send_nonce[NONCEBYTES];
- uint8_t receive_nonce[NONCEBYTES];
-
- struct timespec receive_last;
- uint64_t receive_reorder_seen;
-};
-
-
-static inline void increment_nonce(uint8_t nonce[NONCEBYTES]) {
- nonce[0] += 2;
-
- if (nonce[0] == 0 || nonce[0] == 1) {
- int i;
- for (i = 1; i < NONCEBYTES; i++) {
- nonce[i]++;
- if (nonce[i] != 0)
- break;
- }
- }
-}
-
-static inline bool is_nonce_valid(const uint8_t nonce[NONCEBYTES], const uint8_t old_nonce[NONCEBYTES], int64_t *age) {
- if ((nonce[0] & 1) != (old_nonce[0] & 1))
- return false;
-
- int i;
- *age = 0;
-
- for (i = NONCEBYTES-1; i >= 0; i--) {
- *age *= 256;
- *age += old_nonce[i]-nonce[i];
- }
-
- *age /= 2;
- return true;
-}
-
-static size_t method_max_packet_size(fastd_context_t *ctx) {
- return (fastd_max_packet_size(ctx) + NONCEBYTES + crypto_secretbox_xsalsa20poly1305_ZEROBYTES - crypto_secretbox_xsalsa20poly1305_BOXZEROBYTES);
-}
-
-static size_t method_min_encrypt_head_space(fastd_context_t *ctx UNUSED) {
- return crypto_secretbox_xsalsa20poly1305_ZEROBYTES;
-}
-
-static size_t method_min_decrypt_head_space(fastd_context_t *ctx UNUSED) {
- return (crypto_secretbox_xsalsa20poly1305_BOXZEROBYTES - NONCEBYTES);
-}
-
-static size_t method_min_tail_space(fastd_context_t *ctx UNUSED) {
- return 0;
-}
-
-static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, uint8_t *secret, size_t length, bool initiator) {
- int i;
-
- if (length < crypto_secretbox_xsalsa20poly1305_KEYBYTES)
- exit_bug(ctx, "xsalsa20-poly1305: tried to init with short secret");
-
- fastd_method_session_state_t *session = malloc(sizeof(fastd_method_session_state_t));
-
- session->valid_till = ctx->now;
- session->valid_till.tv_sec += ctx->conf->key_valid;
-
- session->refresh_after = ctx->now;
- session->refresh_after.tv_sec += ctx->conf->key_refresh - fastd_rand(ctx, 0, ctx->conf->key_refresh_splay);
-
- memcpy(session->key, secret, crypto_secretbox_xsalsa20poly1305_KEYBYTES);
-
- session->send_nonce[0] = initiator ? 3 : 2;
- session->receive_nonce[0] = initiator ? 0 : 1;
-
- for (i = 1; i < NONCEBYTES; i++) {
- session->send_nonce[i] = 0;
- session->receive_nonce[i] = 0;
- }
-
- return session;
-}
-
-static bool method_session_is_valid(fastd_context_t *ctx, fastd_method_session_state_t *session) {
- return (session && timespec_after(&session->valid_till, &ctx->now));
-}
-
-static bool method_session_is_initiator(fastd_context_t *ctx UNUSED, fastd_method_session_state_t *session) {
- return (session->send_nonce[0] & 1);
-}
-
-static bool method_session_want_refresh(fastd_context_t *ctx, fastd_method_session_state_t *session) {
- return timespec_after(&ctx->now, &session->refresh_after);
-}
-
-static void method_session_superseded(fastd_context_t *ctx, fastd_method_session_state_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 void method_session_free(fastd_context_t *ctx UNUSED, fastd_method_session_state_t *session) {
- if(session) {
- secure_memzero(session, sizeof(fastd_method_session_state_t));
- free(session);
- }
-}
-
-static bool method_encrypt(fastd_context_t *ctx, fastd_peer_t *peer UNUSED, fastd_method_session_state_t *session, fastd_buffer_t *out, fastd_buffer_t in) {
- fastd_buffer_pull_head(ctx, &in, crypto_secretbox_xsalsa20poly1305_ZEROBYTES);
- memset(in.data, 0, crypto_secretbox_xsalsa20poly1305_ZEROBYTES);
-
- *out = fastd_buffer_alloc(ctx, in.len, 0, 0);
-
- uint8_t nonce[crypto_secretbox_xsalsa20poly1305_NONCEBYTES];
- memcpy(nonce, session->send_nonce, NONCEBYTES);
- memset(nonce+NONCEBYTES, 0, crypto_secretbox_xsalsa20poly1305_NONCEBYTES-NONCEBYTES);
-
- crypto_secretbox_xsalsa20poly1305(out->data, in.data, in.len, nonce, session->key);
-
- fastd_buffer_free(in);
-
- fastd_buffer_push_head(ctx, out, crypto_secretbox_xsalsa20poly1305_BOXZEROBYTES-NONCEBYTES);
- memcpy(out->data, session->send_nonce, NONCEBYTES);
-
- increment_nonce(session->send_nonce);
-
- return true;
-}
-
-static bool method_decrypt(fastd_context_t *ctx, fastd_peer_t *peer, fastd_method_session_state_t *session, fastd_buffer_t *out, fastd_buffer_t in) {
- if (in.len < NONCEBYTES)
- return false;
-
- if (!method_session_is_valid(ctx, session))
- return false;
-
- uint8_t nonce[crypto_secretbox_xsalsa20poly1305_NONCEBYTES];
- memcpy(nonce, in.data, NONCEBYTES);
- memset(nonce+NONCEBYTES, 0, crypto_secretbox_xsalsa20poly1305_NONCEBYTES-NONCEBYTES);
-
- int64_t age;
- if (!is_nonce_valid(nonce, session->receive_nonce, &age))
- return false;
-
- if (age >= 0) {
- if (timespec_diff(&ctx->now, &session->receive_last) > (int)ctx->conf->reorder_time*1000)
- return false;
-
- if (age > ctx->conf->reorder_count)
- return false;
- }
-
- fastd_buffer_pull_head(ctx, &in, crypto_secretbox_xsalsa20poly1305_BOXZEROBYTES-NONCEBYTES);
- memset(in.data, 0, crypto_secretbox_xsalsa20poly1305_BOXZEROBYTES);
-
- *out = fastd_buffer_alloc(ctx, in.len, 0, 0);
-
- if (crypto_secretbox_xsalsa20poly1305_open(out->data, in.data, in.len, nonce, session->key) != 0) {
- fastd_buffer_free(*out);
-
- /* restore input buffer */
- fastd_buffer_push_head(ctx, &in, crypto_secretbox_xsalsa20poly1305_BOXZEROBYTES-NONCEBYTES);
- memcpy(in.data, nonce, NONCEBYTES);
- return false;
- }
-
- fastd_buffer_free(in);
-
- if (age < 0) {
- session->receive_reorder_seen >>= age;
- session->receive_reorder_seen |= (1 >> (age+1));
- memcpy(session->receive_nonce, nonce, NONCEBYTES);
- session->receive_last = ctx->now;
- }
- else if (age == 0 || session->receive_reorder_seen & (1 << (age-1))) {
- pr_debug(ctx, "dropping duplicate packet from %P (age %u)", peer, (unsigned)age);
- fastd_buffer_free(*out);
- *out = fastd_buffer_alloc(ctx, crypto_secretbox_xsalsa20poly1305_ZEROBYTES, 0, 0);
- }
- else {
- pr_debug2(ctx, "accepting reordered packet from %P (age %u)", peer, (unsigned)age);
- session->receive_reorder_seen |= (1 << (age-1));
- }
-
- fastd_buffer_push_head(ctx, out, crypto_secretbox_xsalsa20poly1305_ZEROBYTES);
-
- return true;
-}
-
-const fastd_method_t fastd_method_xsalsa20_poly1305 = {
- .name = "xsalsa20-poly1305",
-
- .max_packet_size = method_max_packet_size,
- .min_encrypt_head_space = method_min_encrypt_head_space,
- .min_decrypt_head_space = method_min_decrypt_head_space,
- .min_encrypt_tail_space = method_min_tail_space,
- .min_decrypt_tail_space = method_min_tail_space,
-
- .session_init = method_session_init,
- .session_is_valid = method_session_is_valid,
- .session_is_initiator = method_session_is_initiator,
- .session_want_refresh = method_session_want_refresh,
- .session_superseded = method_session_superseded,
- .session_free = method_session_free,
-
- .encrypt = method_encrypt,
- .decrypt = method_decrypt,
-};