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authorMatthias Schiffer <mschiffer@universe-factory.net>2012-04-22 21:34:35 +0200
committerMatthias Schiffer <mschiffer@universe-factory.net>2012-04-22 21:34:35 +0200
commit80f8c201e86beddf4bdb0e470cb8e11a60509773 (patch)
tree10d7f1d04c10e1a0636384d0551340069c279546 /src
parent1bbef32baabfa9da3bb55754da06c0b05550aa46 (diff)
downloadfastd-0.4-rc2.tar
fastd-0.4-rc2.zip
Ignore handshakes for 15 seconds after session establishment to avoid excessive and concurrent handshakesv0.4-rc2
Diffstat (limited to 'src')
-rw-r--r--src/protocol_ec25519_fhmqvc.c57
1 files changed, 46 insertions, 11 deletions
diff --git a/src/protocol_ec25519_fhmqvc.c b/src/protocol_ec25519_fhmqvc.c
index 3cd25b8..fd4676f 100644
--- a/src/protocol_ec25519_fhmqvc.c
+++ b/src/protocol_ec25519_fhmqvc.c
@@ -76,6 +76,8 @@ struct _fastd_protocol_peer_config {
};
typedef struct _protocol_session {
+ struct timespec established;
+
bool handshakes_cleaned;
bool refreshing;
@@ -121,6 +123,23 @@ static inline bool is_session_valid(fastd_context *ctx, const protocol_session *
return ctx->conf->method->session_is_valid(ctx, session->method_state);
}
+static fastd_peer* get_peer(fastd_context *ctx, const fastd_peer_config *peer_conf) {
+ fastd_peer *peer;
+ for (peer = ctx->peers; peer; peer = peer->next) {
+ if (peer->config == peer_conf)
+ break;
+ }
+ if (!peer)
+ exit_bug(ctx, "no peer for config found");
+
+ return peer;
+}
+
+static bool backoff(fastd_context *ctx, const fastd_peer *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 *ctx, fastd_peer *peer) {
protocol_session *session = &peer->protocol_state->session;
@@ -289,22 +308,28 @@ static void respond_handshake(fastd_context *ctx, const fastd_peer_address *addr
fastd_send_handshake(ctx, address, buffer);
}
-static void establish(fastd_context *ctx, const fastd_peer_config *peer_conf, const fastd_peer_address *address, bool initiator,
+static bool establish(fastd_context *ctx, const fastd_peer_config *peer_conf, const fastd_peer_address *address, bool initiator,
const ecc_public_key_256 *A, const ecc_public_key_256 *B, const ecc_public_key_256 *X,
const ecc_public_key_256 *Y, const ecc_public_key_256 *sigma) {
uint8_t hashinput[5*PUBLICKEYBYTES];
uint8_t hash[HASHBYTES];
- fastd_peer *peer;
- for (peer = ctx->peers; peer; peer = peer->next) {
- if (peer->config == peer_conf)
- break;
- }
- if (!peer)
- exit_bug(ctx, "no peer for config found");
+ fastd_peer *peer = get_peer(ctx, peer_conf);
pr_verbose(ctx, "%I authorized as %P", address, peer);
+ /*if (backoff(ctx, peer)) {
+ if (initiator == ctx->conf->method->session_is_initiator(ctx, peer->protocol_state->session.method_state)) {
+ pr_verbose(ctx, "received repeated handshakes from %P, ignoring", peer);
+ }
+ else {
+ pr_verbose(ctx, "mismatched concurrent handshakes with %P, resetting", peer);
+ fastd_peer_reset(ctx, peer);
+ }
+
+ return false;
+ }*/
+
init_peer_state(ctx, peer);
if (is_session_valid(ctx, &peer->protocol_state->session) && !is_session_valid(ctx, &peer->protocol_state->old_session)) {
@@ -322,6 +347,7 @@ static void establish(fastd_context *ctx, const fastd_peer_config *peer_conf, co
memcpy(hashinput+4*PUBLICKEYBYTES, sigma->p, PUBLICKEYBYTES);
crypto_hash_sha256(hash, hashinput, 5*PUBLICKEYBYTES);
+ 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_state = ctx->conf->method->session_init(ctx, hash, HASHBYTES, initiator);
@@ -331,7 +357,7 @@ static void establish(fastd_context *ctx, const fastd_peer_config *peer_conf, co
if (!fastd_peer_claim_address(ctx, peer, address)) {
pr_warn(ctx, "can't set address %I which is used by a fixed peer", ctx->resolve_returns->addr);
fastd_peer_reset(ctx, peer);
- return;
+ return false;
}
fastd_peer_set_established(ctx, peer);
@@ -342,6 +368,8 @@ static void establish(fastd_context *ctx, const fastd_peer_config *peer_conf, co
if (!initiator)
protocol_send(ctx, peer, fastd_buffer_alloc(0, ctx->conf->method->min_encrypt_head_space(ctx), 0));
+
+ return true;
}
static void finish_handshake(fastd_context *ctx, const fastd_peer_address *address, const fastd_peer_config *peer_conf, const handshake_key *handshake_key, const ecc_public_key_256 *peer_handshake_key, const fastd_handshake *handshake) {
@@ -399,6 +427,10 @@ static void finish_handshake(fastd_context *ctx, const fastd_peer_address *addre
memcpy(hashinput+PUBLICKEYBYTES, handshake_key->public_key.p, PUBLICKEYBYTES);
crypto_auth_hmacsha256(hmacbuf, hashinput, 2*PUBLICKEYBYTES, shared_handshake_key);
+ if (!establish(ctx, peer_conf, address, true, &handshake_key->public_key, peer_handshake_key, &ctx->conf->protocol_config->public_key,
+ &peer_conf->protocol_config->public_key, &sigma))
+ return;
+
fastd_buffer buffer = fastd_handshake_new_reply(ctx, handshake, 4*(4+PUBLICKEYBYTES) + 4+HMACBYTES);
fastd_handshake_add(ctx, &buffer, RECORD_SENDER_KEY, PUBLICKEYBYTES, ctx->conf->protocol_config->public_key.p);
@@ -409,8 +441,6 @@ static void finish_handshake(fastd_context *ctx, const fastd_peer_address *addre
fastd_send_handshake(ctx, address, buffer);
- establish(ctx, peer_conf, address, true, &handshake_key->public_key, peer_handshake_key, &ctx->conf->protocol_config->public_key,
- &peer_conf->protocol_config->public_key, &sigma);
}
static void handle_finish_handshake(fastd_context *ctx, const fastd_peer_address *address, const fastd_peer_config *peer_conf, const handshake_key *handshake_key, const ecc_public_key_256 *peer_handshake_key, const fastd_handshake *handshake) {
@@ -514,6 +544,11 @@ static void protocol_handshake_handle(fastd_context *ctx, const fastd_peer_addre
return;
}
+ if (backoff(ctx, get_peer(ctx, peer_conf))) {
+ pr_verbose(ctx, "received repeated handshakes from %I, ignoring", address);
+ return;
+ }
+
if (handshake->type > 1 && !has_field(handshake, RECORD_RECEIPIENT_KEY, PUBLICKEYBYTES)) {
pr_debug(ctx, "received handshake reply without receipient key from %I", address);
return;