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-rw-r--r--src/protocol_ec25519_fhmqvc.c1015
1 files changed, 0 insertions, 1015 deletions
diff --git a/src/protocol_ec25519_fhmqvc.c b/src/protocol_ec25519_fhmqvc.c
deleted file mode 100644
index b7b5162..0000000
--- a/src/protocol_ec25519_fhmqvc.c
+++ /dev/null
@@ -1,1015 +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 "handshake.h"
-#include "peer.h"
-#include "sha256.h"
-
-
-#include <libuecc/ecc.h>
-
-
-#define PUBLICKEYBYTES 32
-#define SECRETKEYBYTES 32
-#define HASHBYTES FASTD_SHA256_HASH_BYTES
-
-
-#if HASHBYTES != FASTD_HMACSHA256_KEY_BYTES
-#error bug: HASHBYTES != FASTD_HMACSHA256_KEY_BYTES
-#endif
-
-#if HASHBYTES != SECRETKEYBYTES
-#error bug: HASHBYTES != SECRETKEYBYTES
-#endif
-
-
-typedef ecc_int256_t __attribute__((aligned(4))) aligned_int256_t;
-
-typedef struct keypair {
- ecc_int256_t secret;
- aligned_int256_t public;
-} keypair_t;
-
-struct fastd_protocol_config {
- keypair_t key;
-};
-
-typedef struct handshake_key {
- uint64_t serial;
- struct timespec preferred_till;
- struct timespec valid_till;
-
- /* keypair used as initiator */
- keypair_t key1;
-
- /* keypair used as responder */
- keypair_t key2;
-} handshake_key_t;
-
-struct fastd_protocol_state {
- handshake_key_t prev_handshake_key;
- handshake_key_t handshake_key;
-};
-
-struct fastd_protocol_peer_config {
- aligned_int256_t public_key;
-};
-
-typedef struct protocol_session {
- struct timespec established;
-
- bool handshakes_cleaned;
- bool refreshing;
-
- const fastd_method_t *method;
- fastd_method_session_state_t *method_state;
-} protocol_session_t;
-
-struct fastd_protocol_peer_state {
- protocol_session_t old_session;
- protocol_session_t session;
-
- uint64_t last_serial;
-
- /* handshake cache */
- uint64_t last_handshake_serial;
- aligned_int256_t peer_handshake_key;
- aligned_int256_t sigma;
- fastd_sha256_t shared_handshake_key;
-};
-
-
-#define RECORD_SENDER_KEY RECORD_PROTOCOL1
-#define RECORD_RECEIPIENT_KEY RECORD_PROTOCOL2
-#define RECORD_SENDER_HANDSHAKE_KEY RECORD_PROTOCOL3
-#define RECORD_RECEIPIENT_HANDSHAKE_KEY RECORD_PROTOCOL4
-#define RECORD_T RECORD_PROTOCOL5
-
-
-static void send_empty(fastd_context_t *ctx, fastd_peer_t *peer, protocol_session_t *session);
-
-
-static inline bool read_key(uint8_t key[32], const char *hexkey) {
- if ((strlen(hexkey) != 64) || (strspn(hexkey, "0123456789abcdefABCDEF") != 64))
- return false;
-
- int i;
- for (i = 0; i < 32; i++)
- sscanf(&hexkey[2*i], "%02hhx", &key[i]);
-
- return true;
-}
-
-static inline bool is_handshake_key_valid(fastd_context_t *ctx, const handshake_key_t *handshake_key) {
- return timespec_after(&handshake_key->valid_till, &ctx->now);
-}
-
-static inline bool is_handshake_key_preferred(fastd_context_t *ctx, const handshake_key_t *handshake_key) {
- return timespec_after(&handshake_key->preferred_till, &ctx->now);
-}
-
-static inline bool is_session_valid(fastd_context_t *ctx, const protocol_session_t *session) {
- return (session->method && session->method->session_is_valid(ctx, session->method_state));
-}
-
-static bool backoff(fastd_context_t *ctx, const fastd_peer_t *peer) {
- return (peer->protocol_state && is_session_valid(ctx, &peer->protocol_state->session)
- && timespec_diff(&ctx->now, &peer->protocol_state->session.established) < 15000);
-}
-
-static inline void check_session_refresh(fastd_context_t *ctx, fastd_peer_t *peer) {
- protocol_session_t *session = &peer->protocol_state->session;
-
- if (!session->refreshing && session->method->session_is_initiator(ctx, session->method_state) && session->method->session_want_refresh(ctx, session->method_state)) {
- pr_verbose(ctx, "refreshing session with %P", peer);
- session->handshakes_cleaned = true;
- session->refreshing = true;
- fastd_peer_schedule_handshake(ctx, peer, 0);
- }
-}
-
-static fastd_protocol_config_t* protocol_init(fastd_context_t *ctx) {
- fastd_protocol_config_t *protocol_config = malloc(sizeof(fastd_protocol_config_t));
-
- if (!ctx->conf->secret)
- exit_error(ctx, "no secret key configured");
-
- if (!read_key(protocol_config->key.secret.p, ctx->conf->secret))
- exit_error(ctx, "invalid secret key");
-
- ecc_25519_work_t work;
- ecc_25519_scalarmult_base(&work, &protocol_config->key.secret);
- ecc_25519_store_packed(&protocol_config->key.public, &work);
-
- return protocol_config;
-}
-
-static inline void hexdump(char out[65], const unsigned char d[32]) {
- int i;
- for (i = 0; i < 32; i++)
- snprintf(out+2*i, 3, "%02x", d[i]);
-}
-
-static size_t key_count(fastd_context_t *ctx, const unsigned char key[32]) {
- size_t ret = 0;
-
- fastd_peer_config_t *p;
- for (p = ctx->conf->peers; p; p = p->next) {
- if (!p->protocol_config)
- continue;
-
- if (memcmp(p->protocol_config->public_key.p, key, 32) == 0)
- ret++;
- }
-
- return ret;
-}
-
-static void protocol_peer_configure(fastd_context_t *ctx, fastd_peer_config_t *peer_conf) {
- if (peer_conf->protocol_config)
- return;
-
- if (!peer_conf->key) {
- pr_warn(ctx, "no key configured for `%s', disabling peer", peer_conf->name);
- return;
- }
-
- aligned_int256_t key;
- if (!read_key(key.p, peer_conf->key)) {
- pr_warn(ctx, "invalid key configured for `%s', disabling peer", peer_conf->name);
- return;
- }
-
- peer_conf->protocol_config = malloc(sizeof(fastd_protocol_peer_config_t));
- peer_conf->protocol_config->public_key = key;
-
- if (memcmp(peer_conf->protocol_config->public_key.p, ctx->conf->protocol_config->key.public.p, 32) == 0)
- pr_debug(ctx, "found own key as `%s', ignoring peer", peer_conf->name);
-}
-
-static bool protocol_peer_check(fastd_context_t *ctx, fastd_peer_config_t *peer_conf) {
- if (!peer_conf->protocol_config)
- return false;
-
- if (memcmp(peer_conf->protocol_config->public_key.p, ctx->conf->protocol_config->key.public.p, 32) == 0)
- return false;
-
- if (key_count(ctx, peer_conf->protocol_config->public_key.p) > 1) {
- char buf[65];
- hexdump(buf, peer_conf->protocol_config->public_key.p);
- pr_warn(ctx, "more than one peer is configured with key %s, disabling %s", buf, peer_conf->name);
- return false;
- }
-
- return true;
-}
-
-static bool protocol_peer_check_temporary(fastd_context_t *ctx, fastd_peer_t *peer) {
- if (key_count(ctx, peer->protocol_config->public_key.p)) {
- char buf[65];
- hexdump(buf, peer->protocol_config->public_key.p);
- pr_info(ctx, "key %s is configured now, deleting temporary peer.", buf);
- return false;
- }
-
- return true;
-}
-
-static void init_protocol_state(fastd_context_t *ctx) {
- if (!ctx->protocol_state) {
- ctx->protocol_state = calloc(1, sizeof(fastd_protocol_state_t));
-
- ctx->protocol_state->prev_handshake_key.preferred_till = ctx->conf->long_ago;
- ctx->protocol_state->handshake_key.preferred_till = ctx->conf->long_ago;
- }
-}
-
-static void new_handshake_key(fastd_context_t *ctx, keypair_t *key) {
- fastd_random_bytes(ctx, key->secret.p, 32, false);
- ecc_25519_gf_sanitize_secret(&key->secret, &key->secret);
-
- ecc_25519_work_t work;
- ecc_25519_scalarmult_base(&work, &key->secret);
- ecc_25519_store_packed(&key->public, &work);
-}
-
-static void maintenance(fastd_context_t *ctx) {
- init_protocol_state(ctx);
-
- if (!is_handshake_key_preferred(ctx, &ctx->protocol_state->handshake_key)) {
- pr_debug(ctx, "generating new handshake key");
-
- ctx->protocol_state->prev_handshake_key = ctx->protocol_state->handshake_key;
-
- ctx->protocol_state->handshake_key.serial++;
-
- new_handshake_key(ctx, &ctx->protocol_state->handshake_key.key1);
- new_handshake_key(ctx, &ctx->protocol_state->handshake_key.key2);
-
- ctx->protocol_state->handshake_key.preferred_till = ctx->now;
- ctx->protocol_state->handshake_key.preferred_till.tv_sec += 15;
-
- ctx->protocol_state->handshake_key.valid_till = ctx->now;
- ctx->protocol_state->handshake_key.valid_till.tv_sec += 30;
- }
-}
-
-static void protocol_handshake_init(fastd_context_t *ctx, const fastd_socket_t *sock, const fastd_peer_address_t *local_addr, const fastd_peer_address_t *remote_addr, fastd_peer_t *peer) {
- maintenance(ctx);
-
- fastd_buffer_t buffer = fastd_handshake_new_init(ctx, 3*(4+PUBLICKEYBYTES) /* sender key, receipient key, handshake key */);
-
- fastd_handshake_add(ctx, &buffer, RECORD_SENDER_KEY, PUBLICKEYBYTES, ctx->conf->protocol_config->key.public.p);
-
- if (peer)
- fastd_handshake_add(ctx, &buffer, RECORD_RECEIPIENT_KEY, PUBLICKEYBYTES, peer->protocol_config->public_key.p);
- else
- pr_debug(ctx, "sending handshake to unknown peer %I", remote_addr);
-
- fastd_handshake_add(ctx, &buffer, RECORD_SENDER_HANDSHAKE_KEY, PUBLICKEYBYTES, ctx->protocol_state->handshake_key.key1.public.p);
-
- fastd_send_handshake(ctx, sock, local_addr, remote_addr, peer, buffer);
-}
-
-
-static bool update_shared_handshake_key(fastd_context_t *ctx, const fastd_peer_t *peer, const handshake_key_t *handshake_key, const aligned_int256_t *peer_handshake_key) {
- if (peer->protocol_state->last_handshake_serial == handshake_key->serial) {
- if (memcmp(&peer->protocol_state->peer_handshake_key, peer_handshake_key, PUBLICKEYBYTES) == 0)
- return true;
- }
-
- fastd_sha256_t hashbuf;
- fastd_sha256_blocks(&hashbuf,
- handshake_key->key2.public.p,
- peer_handshake_key->p,
- ctx->conf->protocol_config->key.public.p,
- peer->protocol_config->public_key.p,
- NULL);
-
- ecc_int256_t d = {{0}}, e = {{0}}, eb, s;
-
- memcpy(d.p, hashbuf.b, HASHBYTES/2);
- memcpy(e.p, hashbuf.b+HASHBYTES/2, HASHBYTES/2);
-
- d.p[15] |= 0x80;
- e.p[15] |= 0x80;
-
- ecc_25519_gf_mult(&eb, &e, &ctx->conf->protocol_config->key.secret);
- ecc_25519_gf_add(&s, &eb, &handshake_key->key2.secret);
-
- ecc_25519_work_t work, workX;
- if (!ecc_25519_load_packed(&workX, peer_handshake_key))
- return false;
-
- ecc_25519_scalarmult(&work, &ecc_25519_gf_order, &workX);
- if (!ecc_25519_is_identity(&work))
- return false;
-
- if (!ecc_25519_load_packed(&work, &peer->protocol_config->public_key))
- return false;
-
- ecc_25519_scalarmult(&work, &d, &work);
- ecc_25519_add(&work, &workX, &work);
- ecc_25519_scalarmult(&work, &s, &work);
-
- if (ecc_25519_is_identity(&work))
- return false;
-
- ecc_25519_store_packed(&peer->protocol_state->sigma, &work);
-
- fastd_sha256_blocks(&peer->protocol_state->shared_handshake_key,
- handshake_key->key2.public.p,
- peer_handshake_key->p,
- ctx->conf->protocol_config->key.public.p,
- peer->protocol_config->public_key.p,
- peer->protocol_state->sigma.p,
- NULL);
-
- peer->protocol_state->last_handshake_serial = handshake_key->serial;
- peer->protocol_state->peer_handshake_key = *peer_handshake_key;
-
- return true;
-}
-
-static void clear_shared_handshake_key(fastd_context_t *ctx UNUSED, const fastd_peer_t *peer) {
- memset(&peer->protocol_state->sigma, 0, sizeof(peer->protocol_state->sigma));
- memset(&peer->protocol_state->shared_handshake_key, 0, sizeof(peer->protocol_state->shared_handshake_key));
-
- peer->protocol_state->last_handshake_serial = 0;
- memset(&peer->protocol_state->peer_handshake_key, 0, sizeof(peer->protocol_state->peer_handshake_key));
-}
-
-static void respond_handshake(fastd_context_t *ctx, const fastd_socket_t *sock, const fastd_peer_address_t *local_addr, const fastd_peer_address_t *remote_addr, fastd_peer_t *peer,
- const handshake_key_t *handshake_key, const aligned_int256_t *peer_handshake_key, const fastd_handshake_t *handshake, const fastd_method_t *method) {
- pr_debug(ctx, "responding handshake with %P[%I]...", peer, remote_addr);
-
- if (!update_shared_handshake_key(ctx, peer, handshake_key, peer_handshake_key))
- return;
-
- fastd_buffer_t buffer = fastd_handshake_new_reply(ctx, handshake, method, true, 4*(4+PUBLICKEYBYTES) + 2*(4+HASHBYTES));
-
- fastd_handshake_add(ctx, &buffer, RECORD_SENDER_KEY, PUBLICKEYBYTES, ctx->conf->protocol_config->key.public.p);
- fastd_handshake_add(ctx, &buffer, RECORD_RECEIPIENT_KEY, PUBLICKEYBYTES, peer->protocol_config->public_key.p);
- fastd_handshake_add(ctx, &buffer, RECORD_SENDER_HANDSHAKE_KEY, PUBLICKEYBYTES, handshake_key->key2.public.p);
- fastd_handshake_add(ctx, &buffer, RECORD_RECEIPIENT_HANDSHAKE_KEY, PUBLICKEYBYTES, peer_handshake_key->p);
-
- fastd_sha256_t hmacbuf;
-
- if (!ctx->conf->secure_handshakes) {
- fastd_hmacsha256_blocks(&hmacbuf, peer->protocol_state->shared_handshake_key.w, ctx->conf->protocol_config->key.public.p, handshake_key->key2.public.p, NULL);
- fastd_handshake_add(ctx, &buffer, RECORD_T, HASHBYTES, hmacbuf.b);
- }
-
- memset(&hmacbuf, 0, sizeof(hmacbuf));
- fastd_handshake_add(ctx, &buffer, RECORD_TLV_MAC, HASHBYTES, hmacbuf.b);
- fastd_hmacsha256(&hmacbuf, peer->protocol_state->shared_handshake_key.w, fastd_handshake_tlv_data(&buffer), fastd_handshake_tlv_len(&buffer));
- memcpy(buffer.data+buffer.len-HASHBYTES, hmacbuf.b, HASHBYTES);
-
- fastd_send_handshake(ctx, sock, local_addr, remote_addr, peer, buffer);
-}
-
-static bool establish(fastd_context_t *ctx, fastd_peer_t *peer, const fastd_method_t *method, fastd_socket_t *sock,
- const fastd_peer_address_t *local_addr, const fastd_peer_address_t *remote_addr, bool initiator,
- const aligned_int256_t *A, const aligned_int256_t *B, const aligned_int256_t *X,
- const aligned_int256_t *Y, const aligned_int256_t *sigma, uint64_t serial) {
- if (serial <= peer->protocol_state->last_serial) {
- pr_debug(ctx, "ignoring handshake from %P[%I] because of handshake key reuse", peer, remote_addr);
- return false;
- }
-
- pr_verbose(ctx, "%I authorized as %P", remote_addr, peer);
-
- if (!fastd_peer_claim_address(ctx, peer, sock, local_addr, remote_addr)) {
- pr_warn(ctx, "can't set address %I which is used by a fixed peer", remote_addr);
- fastd_peer_reset(ctx, peer);
- return false;
- }
-
- if (is_session_valid(ctx, &peer->protocol_state->session) && !is_session_valid(ctx, &peer->protocol_state->old_session)) {
- if (peer->protocol_state->old_session.method)
- peer->protocol_state->old_session.method->session_free(ctx, peer->protocol_state->old_session.method_state);
- peer->protocol_state->old_session = peer->protocol_state->session;
- }
- else {
- if (peer->protocol_state->session.method)
- peer->protocol_state->session.method->session_free(ctx, peer->protocol_state->session.method_state);
- }
-
- if (peer->protocol_state->old_session.method) {
- if (peer->protocol_state->old_session.method != method) {
- pr_debug(ctx, "method of %P[%I] has changed, terminating old session", peer, remote_addr);
- peer->protocol_state->old_session.method->session_free(ctx, peer->protocol_state->old_session.method_state);
- peer->protocol_state->old_session = (protocol_session_t){};
- }
- else {
- peer->protocol_state->old_session.method->session_superseded(ctx, peer->protocol_state->old_session.method_state);
- }
- }
-
- fastd_sha256_t hash;
- fastd_sha256_blocks(&hash, X->p, Y->p, A->p, B->p, sigma->p, NULL);
-
- peer->protocol_state->session.established = ctx->now;
- peer->protocol_state->session.handshakes_cleaned = false;
- peer->protocol_state->session.refreshing = false;
- peer->protocol_state->session.method = method;
- peer->protocol_state->session.method_state = method->session_init(ctx, hash.b, HASHBYTES, initiator);
- peer->protocol_state->last_serial = serial;
-
- fastd_peer_seen(ctx, peer);
-
- fastd_peer_set_established(ctx, peer);
-
- pr_verbose(ctx, "new session with %P established using method `%s'.", peer, method->name);
-
- if (initiator)
- fastd_peer_schedule_handshake_default(ctx, peer);
- else
- send_empty(ctx, peer, &peer->protocol_state->session);
-
- return true;
-}
-
-static inline bool has_field(const fastd_handshake_t *handshake, uint8_t type, size_t length) {
- return (handshake->records[type].length == length);
-}
-
-static void finish_handshake(fastd_context_t *ctx, fastd_socket_t *sock, const fastd_peer_address_t *local_addr, const fastd_peer_address_t *remote_addr, fastd_peer_t *peer, const handshake_key_t *handshake_key, const aligned_int256_t *peer_handshake_key,
- const fastd_handshake_t *handshake, const fastd_method_t *method) {
- pr_debug(ctx, "finishing handshake with %P[%I]...", peer, remote_addr);
-
- fastd_sha256_t hashbuf;
- fastd_sha256_blocks(&hashbuf,
- peer_handshake_key->p,
- handshake_key->key1.public.p,
- peer->protocol_config->public_key.p,
- ctx->conf->protocol_config->key.public.p,
- NULL);
-
- ecc_int256_t d = {{0}}, e = {{0}}, da, s;
-
- memcpy(d.p, hashbuf.b, HASHBYTES/2);
- memcpy(e.p, hashbuf.b+HASHBYTES/2, HASHBYTES/2);
-
- d.p[15] |= 0x80;
- e.p[15] |= 0x80;
-
- ecc_25519_gf_mult(&da, &d, &ctx->conf->protocol_config->key.secret);
- ecc_25519_gf_add(&s, &da, &handshake_key->key1.secret);
-
- ecc_25519_work_t work, workY;
- if (!ecc_25519_load_packed(&workY, peer_handshake_key))
- return;
-
- ecc_25519_scalarmult(&work, &ecc_25519_gf_order, &workY);
- if (!ecc_25519_is_identity(&work))
- return;
-
- if (!ecc_25519_load_packed(&work, &peer->protocol_config->public_key))
- return;
-
- ecc_25519_scalarmult(&work, &e, &work);
- ecc_25519_add(&work, &workY, &work);
- ecc_25519_scalarmult(&work, &s, &work);
-
- if (ecc_25519_is_identity(&work))
- return;
-
- aligned_int256_t sigma;
- ecc_25519_store_packed(&sigma, &work);
-
- fastd_sha256_t shared_handshake_key;
- fastd_sha256_blocks(&shared_handshake_key,
- peer_handshake_key->p,
- handshake_key->key1.public.p,
- peer->protocol_config->public_key.p,
- ctx->conf->protocol_config->key.public.p,
- sigma.p,
- NULL);
-
- bool valid;
- if (has_field(handshake, RECORD_TLV_MAC, HASHBYTES)) {
- uint8_t mac[HASHBYTES];
- memcpy(mac, handshake->records[RECORD_TLV_MAC].data, HASHBYTES);
- memset(handshake->records[RECORD_TLV_MAC].data, 0, HASHBYTES);
-
- valid = fastd_hmacsha256_verify(mac, shared_handshake_key.w, handshake->tlv_data, handshake->tlv_len);
- }
- else {
- valid = fastd_hmacsha256_blocks_verify(handshake->records[RECORD_T].data, shared_handshake_key.w, peer->protocol_config->public_key.p, peer_handshake_key->p, NULL);
- }
-
- if (!valid) {
- pr_warn(ctx, "received invalid protocol handshake response from %P[%I]", peer, remote_addr);
- return;
- }
-
- if (!establish(ctx, peer, method, sock, local_addr, remote_addr, true, &handshake_key->key1.public, peer_handshake_key, &ctx->conf->protocol_config->key.public,
- &peer->protocol_config->public_key, &sigma, handshake_key->serial))
- return;
-
- fastd_buffer_t buffer = fastd_handshake_new_reply(ctx, handshake, method, false, 4*(4+PUBLICKEYBYTES) + 2*(4+HASHBYTES));
-
- fastd_handshake_add(ctx, &buffer, RECORD_SENDER_KEY, PUBLICKEYBYTES, ctx->conf->protocol_config->key.public.p);
- fastd_handshake_add(ctx, &buffer, RECORD_RECEIPIENT_KEY, PUBLICKEYBYTES, peer->protocol_config->public_key.p);
- fastd_handshake_add(ctx, &buffer, RECORD_SENDER_HANDSHAKE_KEY, PUBLICKEYBYTES, handshake_key->key1.public.p);
- fastd_handshake_add(ctx, &buffer, RECORD_RECEIPIENT_HANDSHAKE_KEY, PUBLICKEYBYTES, peer_handshake_key->p);
-
- fastd_sha256_t hmacbuf;
-
- if (!ctx->conf->secure_handshakes) {
- fastd_hmacsha256_blocks(&hmacbuf, shared_handshake_key.w, ctx->conf->protocol_config->key.public.p, handshake_key->key1.public.p, NULL);
- fastd_handshake_add(ctx, &buffer, RECORD_T, HASHBYTES, hmacbuf.b);
- }
-
- memset(&hmacbuf, 0, sizeof(hmacbuf));
- fastd_handshake_add(ctx, &buffer, RECORD_TLV_MAC, HASHBYTES, hmacbuf.b);
- fastd_hmacsha256(&hmacbuf, shared_handshake_key.w, fastd_handshake_tlv_data(&buffer), fastd_handshake_tlv_len(&buffer));
- memcpy(buffer.data+buffer.len-HASHBYTES, hmacbuf.b, HASHBYTES);
-
- fastd_send_handshake(ctx, sock, local_addr, remote_addr, peer, buffer);
-}
-
-static void handle_finish_handshake(fastd_context_t *ctx, fastd_socket_t *sock, const fastd_peer_address_t *local_addr, const fastd_peer_address_t *remote_addr,
- fastd_peer_t *peer, const handshake_key_t *handshake_key, const aligned_int256_t *peer_handshake_key,
- const fastd_handshake_t *handshake, const fastd_method_t *method) {
- pr_debug(ctx, "handling handshake finish with %P[%I]...", peer, remote_addr);
-
- if (!update_shared_handshake_key(ctx, peer, handshake_key, peer_handshake_key))
- return;
-
- bool valid;
- if (has_field(handshake, RECORD_TLV_MAC, HASHBYTES)) {
- uint8_t mac[HASHBYTES];
- memcpy(mac, handshake->records[RECORD_TLV_MAC].data, HASHBYTES);
- memset(handshake->records[RECORD_TLV_MAC].data, 0, HASHBYTES);
-
- valid = fastd_hmacsha256_verify(mac, peer->protocol_state->shared_handshake_key.w, handshake->tlv_data, handshake->tlv_len);
- }
- else {
- valid = fastd_hmacsha256_blocks_verify(handshake->records[RECORD_T].data, peer->protocol_state->shared_handshake_key.w, peer->protocol_config->public_key.p, peer_handshake_key->p, NULL);
- }
-
- if (!valid) {
- pr_warn(ctx, "received invalid protocol handshake finish from %P[%I]", peer, remote_addr);
- return;
- }
-
- establish(ctx, peer, method, sock, local_addr, remote_addr, false, peer_handshake_key, &handshake_key->key2.public, &peer->protocol_config->public_key,
- &ctx->conf->protocol_config->key.public, &peer->protocol_state->sigma, handshake_key->serial);
-
- clear_shared_handshake_key(ctx, peer);
-}
-
-static fastd_peer_t* find_sender_key(fastd_context_t *ctx, const fastd_peer_address_t *address, const unsigned char key[32], fastd_peer_t *peers) {
- errno = 0;
-
- fastd_peer_t *ret = NULL, *peer;
-
- for (peer = peers; peer; peer = peer->next) {
- if (memcmp(peer->protocol_config->public_key.p, key, PUBLICKEYBYTES) == 0) {
- if (!fastd_peer_matches_address(ctx, peer, address)) {
- errno = EPERM;
- return NULL;
- }
-
- ret = peer;
- continue;
- }
-
- if (fastd_peer_owns_address(ctx, peer, address)) {
- errno = EPERM;
- return NULL;
- }
- }
-
- if (!ret)
- errno = ENOENT;
-
- return ret;
-}
-
-static fastd_peer_t* match_sender_key(fastd_context_t *ctx, const fastd_socket_t *sock, const fastd_peer_address_t *address, fastd_peer_t *peer, const unsigned char key[32]) {
- errno = 0;
-
- if (sock->peer && peer != sock->peer)
- exit_bug(ctx, "packet without correct peer set on dynamic socket");
-
- if (peer) {
- if (memcmp(peer->protocol_config->public_key.p, key, PUBLICKEYBYTES) == 0)
- return peer;
-
- if (fastd_peer_owns_address(ctx, peer, address)) {
- errno = EPERM;
- return NULL;
- }
- }
-
- peer = find_sender_key(ctx, address, key, ctx->peers);
-
- if (!peer && errno == ENOENT)
- peer = find_sender_key(ctx, address, key, ctx->peers_temp);
-
- return peer;
-}
-
-static inline fastd_peer_t* add_temporary(fastd_context_t *ctx, const fastd_peer_address_t *local_addr, const fastd_peer_address_t *remote_addr, const unsigned char key[32]) {
- if (!fastd_peer_allow_unknown(ctx)) {
- pr_debug(ctx, "ignoring handshake from %I (unknown key)", remote_addr);
- return NULL;
- }
-
- if (key_count(ctx, key)) {
- pr_debug(ctx, "ignoring handshake from %I (disabled key)", remote_addr);
- return NULL;
- }
-
- fastd_peer_t *peer = fastd_peer_add_temporary(ctx);
-
- peer->protocol_config = malloc(sizeof(fastd_protocol_peer_config_t));
- memcpy(peer->protocol_config->public_key.p, key, PUBLICKEYBYTES);
-
- /* Ugly hack */
- peer->protocol_state->last_serial--;
-
- if (!fastd_peer_verify_temporary(ctx, peer, local_addr, remote_addr)) {
- pr_debug(ctx, "ignoring handshake from %P[%I] (verification failed)", peer, remote_addr);
- fastd_peer_delete(ctx, peer);
- return NULL;
- }
-
- return peer;
-}
-
-static inline keypair_t* get_handshake_keypair(handshake_key_t *handshake_key, uint8_t type) {
- return (type % 2) ? &handshake_key->key2 : &handshake_key->key1;
-}
-
-static void protocol_handshake_handle(fastd_context_t *ctx, fastd_socket_t *sock, const fastd_peer_address_t *local_addr, const fastd_peer_address_t *remote_addr, fastd_peer_t *peer, const fastd_handshake_t *handshake, const fastd_method_t *method) {
- bool temporary_added = false;
-
- maintenance(ctx);
-
- if (!has_field(handshake, RECORD_SENDER_KEY, PUBLICKEYBYTES)) {
- pr_debug(ctx, "received handshake without sender key from %I", remote_addr);
- return;
- }
-
- peer = match_sender_key(ctx, sock, remote_addr, peer, handshake->records[RECORD_SENDER_KEY].data);
- if (!peer) {
- switch (errno) {
- case EPERM:
- pr_debug(ctx, "ignoring handshake from %I (incorrect source address)", remote_addr);
- return;
-
- case ENOENT:
- peer = add_temporary(ctx, local_addr, remote_addr, handshake->records[RECORD_SENDER_KEY].data);
- if (peer) {
- temporary_added = true;
- break;
- }
-
- return;
-
- default:
- exit_bug(ctx, "match_sender_key: unknown error");
- }
- }
-
- if (fastd_peer_is_temporary(peer) && !temporary_added) {
- if (!fastd_peer_verify_temporary(ctx, peer, local_addr, remote_addr)) {
- pr_debug(ctx, "ignoring handshake from %P[%I] (verification failed)", peer, remote_addr);
- return;
- }
- }
-
- if (!fastd_peer_may_connect(ctx, peer)) {
- pr_debug(ctx, "ignoring handshake from %P[%I] because of local constraints", peer, remote_addr);
- return;
- }
-
- if (backoff(ctx, peer)) {
- pr_debug(ctx, "received repeated handshakes from %P[%I], ignoring", peer, remote_addr);
- return;
- }
-
- if (has_field(handshake, RECORD_RECEIPIENT_KEY, PUBLICKEYBYTES)) {
- if (memcmp(ctx->conf->protocol_config->key.public.p, handshake->records[RECORD_RECEIPIENT_KEY].data, PUBLICKEYBYTES) != 0) {
- pr_debug(ctx, "received protocol handshake with wrong receipient key from %P[%I]", peer, remote_addr);
- return;
- }
- }
-
- if (!has_field(handshake, RECORD_SENDER_HANDSHAKE_KEY, PUBLICKEYBYTES)) {
- pr_debug(ctx, "received handshake without sender handshake key from %P[%I]", peer, remote_addr);
- return;
- }
-
- aligned_int256_t peer_handshake_key;
- memcpy(peer_handshake_key.p, handshake->records[RECORD_SENDER_HANDSHAKE_KEY].data, PUBLICKEYBYTES);
-
- if (handshake->type == 1) {
- if (timespec_diff(&ctx->now, &peer->last_handshake_response) < (int)ctx->conf->min_handshake_interval*1000
- && fastd_peer_address_equal(remote_addr, &peer->last_handshake_response_address)) {
- pr_debug(ctx, "not responding repeated handshake from %P[%I]", peer, remote_addr);
- return;
- }
-
- pr_verbose(ctx, "received handshake from %P[%I]%s%s", peer, remote_addr, handshake->peer_version ? " using fastd " : "", handshake->peer_version ?: "");
-
- peer->last_handshake_response = ctx->now;
- peer->last_handshake_response_address = *remote_addr;
- respond_handshake(ctx, sock, local_addr, remote_addr, peer, &ctx->protocol_state->handshake_key, &peer_handshake_key, handshake, method);
- return;
- }
-
- if (!has_field(handshake, RECORD_RECEIPIENT_KEY, PUBLICKEYBYTES)) {
- pr_debug(ctx, "received handshake reply without receipient key from %P[%I]", peer, remote_addr);
- return;
- }
-
- if (!has_field(handshake, RECORD_RECEIPIENT_HANDSHAKE_KEY, PUBLICKEYBYTES)) {
- pr_debug(ctx, "received handshake reply without receipient handshake key from %P[%I]", peer, remote_addr);
- return;
- }
-
- if (!has_field(handshake, RECORD_TLV_MAC, HASHBYTES)) {
- if (ctx->conf->secure_handshakes || !has_field(handshake, RECORD_T, HASHBYTES)) {
- pr_debug(ctx, "received handshake reply without HMAC from %P[%I]", peer, remote_addr);
- return;
- }
- }
-
- handshake_key_t *handshake_key;
- if (is_handshake_key_valid(ctx, &ctx->protocol_state->handshake_key) &&
- memcmp(get_handshake_keypair(&ctx->protocol_state->handshake_key, handshake->type)->public.p, handshake->records[RECORD_RECEIPIENT_HANDSHAKE_KEY].data, PUBLICKEYBYTES) == 0) {
- handshake_key = &ctx->protocol_state->handshake_key;
- }
- else if (is_handshake_key_valid(ctx, &ctx->protocol_state->prev_handshake_key) &&
- memcmp(get_handshake_keypair(&ctx->protocol_state->prev_handshake_key, handshake->type)->public.p, handshake->records[RECORD_RECEIPIENT_HANDSHAKE_KEY].data, PUBLICKEYBYTES) == 0) {
- handshake_key = &ctx->protocol_state->prev_handshake_key;
- }
- else {
- pr_debug(ctx, "received handshake reply with unexpected receipient handshake key from %P[%I]", peer, remote_addr);
- return;
- }
-
- switch (handshake->type) {
- case 2:
- pr_verbose(ctx, "received handshake response from %P[%I]%s%s", peer, remote_addr, handshake->peer_version ? " using fastd " : "", handshake->peer_version ?: "");
-
- finish_handshake(ctx, sock, local_addr, remote_addr, peer, handshake_key, &peer_handshake_key, handshake, method);
- break;
-
- case 3:
- pr_debug(ctx, "received handshake finish from %P[%I]%s%s", peer, remote_addr, handshake->peer_version ? " using fastd " : "", handshake->peer_version ?: "");
-
- handle_finish_handshake(ctx, sock, local_addr, remote_addr, peer, handshake_key, &peer_handshake_key, handshake, method);
- break;
-
- default:
- pr_debug(ctx, "received handshake reply with unknown type %u from %P[%I]", handshake->type, peer, remote_addr);
- }
-}
-
-static inline bool check_session(fastd_context_t *ctx, fastd_peer_t *peer) {
- if (is_session_valid(ctx, &peer->protocol_state->session))
- return true;
-
- pr_verbose(ctx, "active session with %P timed out", peer);
- fastd_peer_reset(ctx, peer);
- return false;
-}
-
-static void protocol_handle_recv(fastd_context_t *ctx, fastd_peer_t *peer, fastd_buffer_t buffer) {
- if (!peer->protocol_state || !check_session(ctx, peer))
- goto fail;
-
- fastd_buffer_t recv_buffer;
- bool ok = false;
-
- if (is_session_valid(ctx, &peer->protocol_state->old_session)) {
- if (peer->protocol_state->old_session.method->decrypt(ctx, peer, peer->protocol_state->old_session.method_state, &recv_buffer, buffer))
- ok = true;
- }
-
- if (!ok) {
- if (peer->protocol_state->session.method->decrypt(ctx, peer, peer->protocol_state->session.method_state, &recv_buffer, buffer)) {
- ok = true;
-
- if (peer->protocol_state->old_session.method) {
- pr_debug(ctx, "invalidating old session with %P", peer);
- peer->protocol_state->old_session.method->session_free(ctx, peer->protocol_state->old_session.method_state);
- peer->protocol_state->old_session = (protocol_session_t){};
- }
-
- if (!peer->protocol_state->session.handshakes_cleaned) {
- pr_debug(ctx, "cleaning left handshakes with %P", peer);
- fastd_peer_unschedule_handshake(ctx, peer);
- peer->protocol_state->session.handshakes_cleaned = true;
-
- if (peer->protocol_state->session.method->session_is_initiator(ctx, peer->protocol_state->session.method_state))
- send_empty(ctx, peer, &peer->protocol_state->session);
- }
-
- check_session_refresh(ctx, peer);
- }
- }
-
- if (!ok) {
- pr_verbose(ctx, "verification failed for packet received from %P", peer);
- goto fail;
- }
-
- fastd_peer_seen(ctx, peer);
-
- if (recv_buffer.len)
- fastd_handle_receive(ctx, peer, recv_buffer);
- else
- fastd_buffer_free(recv_buffer);
-
- return;
-
- fail:
- fastd_buffer_free(buffer);
-}
-
-static void session_send(fastd_context_t *ctx, fastd_peer_t *peer, fastd_buffer_t buffer, protocol_session_t *session) {
- size_t stat_size = buffer.len;
-
- fastd_buffer_t send_buffer;
- if (!session->method->encrypt(ctx, peer, session->method_state, &send_buffer, buffer)) {
- fastd_buffer_free(buffer);
- return;
- }
-
- fastd_send(ctx, peer->sock, &peer->local_address, &peer->address, peer, send_buffer, stat_size);
- peer->last_send = ctx->now;
-}
-
-static void protocol_send(fastd_context_t *ctx, fastd_peer_t *peer, fastd_buffer_t buffer) {
- if (!peer->protocol_state || !fastd_peer_is_established(peer) || !check_session(ctx, peer)) {
- fastd_buffer_free(buffer);
- return;
- }
-
- check_session_refresh(ctx, peer);
-
- if (peer->protocol_state->session.method->session_is_initiator(ctx, peer->protocol_state->session.method_state) && is_session_valid(ctx, &peer->protocol_state->old_session)) {
- pr_debug2(ctx, "sending packet for old session to %P", peer);
- session_send(ctx, peer, buffer, &peer->protocol_state->old_session);
- }
- else {
- session_send(ctx, peer, buffer, &peer->protocol_state->session);
- }
-}
-
-static void send_empty(fastd_context_t *ctx, fastd_peer_t *peer, protocol_session_t *session) {
- session_send(ctx, peer, fastd_buffer_alloc(ctx, 0, alignto(session->method->min_encrypt_head_space(ctx), 8), session->method->min_encrypt_tail_space(ctx)), session);
-}
-
-static void protocol_init_peer_state(fastd_context_t *ctx, fastd_peer_t *peer) {
- init_protocol_state(ctx);
-
- if (peer->protocol_state)
- exit_bug(ctx, "tried to reinit peer state");
-
- peer->protocol_state = calloc(1, sizeof(fastd_protocol_peer_state_t));
- peer->protocol_state->last_serial = ctx->protocol_state->handshake_key.serial;
-}
-
-static void reset_session(fastd_context_t *ctx, protocol_session_t *session) {
- if (session->method)
- session->method->session_free(ctx, session->method_state);
- secure_memzero(session, sizeof(protocol_session_t));
-}
-
-static void protocol_reset_peer_state(fastd_context_t *ctx, fastd_peer_t *peer) {
- if (!peer->protocol_state)
- return;
-
- reset_session(ctx, &peer->protocol_state->old_session);
- reset_session(ctx, &peer->protocol_state->session);
-}
-
-static void protocol_free_peer_state(fastd_context_t *ctx, fastd_peer_t *peer) {
- if (peer->protocol_state) {
- reset_session(ctx, &peer->protocol_state->old_session);
- reset_session(ctx, &peer->protocol_state->session);
-
- free(peer->protocol_state);
- }
-}
-
-static inline void print_hexdump(const char *desc, unsigned char d[32]) {
- char buf[65];
- hexdump(buf, d);
-
- printf("%s%s\n", desc, buf);
-}
-
-static void protocol_generate_key(fastd_context_t *ctx) {
- ecc_int256_t secret_key;
- ecc_int256_t public_key;
-
- if (!ctx->conf->machine_readable)
- pr_info(ctx, "Reading 32 bytes from /dev/random...");
-
- fastd_random_bytes(ctx, secret_key.p, 32, true);
- ecc_25519_gf_sanitize_secret(&secret_key, &secret_key);
-
- ecc_25519_work_t work;
- ecc_25519_scalarmult_base(&work, &secret_key);
- ecc_25519_store_packed(&public_key, &work);
-
- if (ctx->conf->machine_readable) {
- print_hexdump("", secret_key.p);
- }
- else {
- print_hexdump("Secret: ", secret_key.p);
- print_hexdump("Public: ", public_key.p);
- }
-}
-
-static void protocol_show_key(fastd_context_t *ctx) {
- if (ctx->conf->machine_readable)
- print_hexdump("", ctx->conf->protocol_config->key.public.p);
- else
- print_hexdump("Public: ", ctx->conf->protocol_config->key.public.p);
-}
-
-static void protocol_set_shell_env(fastd_context_t *ctx, const fastd_peer_t *peer) {
- char buf[65];
-
- hexdump(buf, ctx->conf->protocol_config->key.public.p);
- setenv("LOCAL_KEY", buf, 1);
-
- if (peer && peer->protocol_config) {
- hexdump(buf, peer->protocol_config->public_key.p);
- setenv("PEER_KEY", buf, 1);
- }
- else {
- unsetenv("PEER_KEY");
- }
-}
-
-static bool protocol_describe_peer(const fastd_context_t *ctx UNUSED, const fastd_peer_t *peer, char *buf, size_t len) {
- if (peer && peer->protocol_config) {
- char dumpbuf[65];
-
- hexdump(dumpbuf, peer->protocol_config->public_key.p);
- snprintf(buf, len, "%.16s", dumpbuf);
- return true;
- }
- else {
- return false;
- }
-}
-
-const fastd_protocol_t fastd_protocol_ec25519_fhmqvc = {
- .name = "ec25519-fhmqvc",
-
- .init = protocol_init,
- .peer_configure = protocol_peer_configure,
- .peer_check = protocol_peer_check,
- .peer_check_temporary = protocol_peer_check_temporary,
-
- .handshake_init = protocol_handshake_init,
- .handshake_handle = protocol_handshake_handle,
-
- .handle_recv = protocol_handle_recv,
- .send = protocol_send,
-
- .init_peer_state = protocol_init_peer_state,
- .reset_peer_state = protocol_reset_peer_state,
- .free_peer_state = protocol_free_peer_state,
-
- .generate_key = protocol_generate_key,
- .show_key = protocol_show_key,
- .set_shell_env = protocol_set_shell_env,
- .describe_peer = protocol_describe_peer,
-};