diff options
Diffstat (limited to 'src/protocol_ec25519_fhmqvc.c')
| -rw-r--r-- | src/protocol_ec25519_fhmqvc.c | 80 |
1 files changed, 61 insertions, 19 deletions
diff --git a/src/protocol_ec25519_fhmqvc.c b/src/protocol_ec25519_fhmqvc.c index ad65ca7..622f633 100644 --- a/src/protocol_ec25519_fhmqvc.c +++ b/src/protocol_ec25519_fhmqvc.c @@ -370,16 +370,24 @@ static void respond_handshake(fastd_context_t *ctx, const fastd_socket_t *sock, if (!update_shared_handshake_key(ctx, peer, handshake_key, peer_handshake_key)) return; - fastd_sha256_t hmacbuf; - 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_buffer_t buffer = fastd_handshake_new_reply(ctx, handshake, method, 4*(4+PUBLICKEYBYTES) + 4+HASHBYTES); + fastd_buffer_t buffer = fastd_handshake_new_reply(ctx, handshake, method, 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_handshake_add(ctx, &buffer, RECORD_T, HASHBYTES, hmacbuf.b); + + 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_HANDSHAKE_MAC, HASHBYTES, hmacbuf.b); + fastd_hmacsha256(&hmacbuf, peer->protocol_state->shared_handshake_key.w, buffer.data+3, buffer.len-3); + memcpy(buffer.data+buffer.len-HASHBYTES, hmacbuf.b, HASHBYTES); fastd_send_handshake(ctx, sock, local_addr, remote_addr, peer, buffer); } @@ -446,6 +454,10 @@ static bool establish(fastd_context_t *ctx, fastd_peer_t *peer, const fastd_meth 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); @@ -499,25 +511,45 @@ static void finish_handshake(fastd_context_t *ctx, fastd_socket_t *sock, const f sigma.p, NULL); - if(!fastd_hmacsha256_blocks_verify(handshake->records[RECORD_T].data, shared_handshake_key.w, peer->protocol_config->public_key.p, peer_handshake_key->p, NULL)) { + bool valid; + if (has_field(handshake, RECORD_HANDSHAKE_MAC, HASHBYTES)) { + uint8_t mac[HASHBYTES]; + memcpy(mac, handshake->records[RECORD_HANDSHAKE_MAC].data, HASHBYTES); + memset(handshake->records[RECORD_HANDSHAKE_MAC].data, 0, HASHBYTES); + + valid = fastd_hmacsha256_verify(mac, shared_handshake_key.w, handshake->buffer.data+3, handshake->buffer.len-3); + } + 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; } - fastd_sha256_t hmacbuf; - fastd_hmacsha256_blocks(&hmacbuf, shared_handshake_key.w, ctx->conf->protocol_config->key.public.p, handshake_key->key1.public.p, NULL); - 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, 4*(4+PUBLICKEYBYTES) + 4+HASHBYTES); + fastd_buffer_t buffer = fastd_handshake_new_reply(ctx, handshake, method, 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_handshake_add(ctx, &buffer, RECORD_T, HASHBYTES, hmacbuf.b); + + 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_HANDSHAKE_MAC, HASHBYTES, hmacbuf.b); + fastd_hmacsha256(&hmacbuf, shared_handshake_key.w, buffer.data+3, buffer.len-3); + memcpy(buffer.data+buffer.len-HASHBYTES, hmacbuf.b, HASHBYTES); fastd_send_handshake(ctx, sock, local_addr, remote_addr, peer, buffer); } @@ -530,7 +562,19 @@ static void handle_finish_handshake(fastd_context_t *ctx, fastd_socket_t *sock, if (!update_shared_handshake_key(ctx, peer, handshake_key, peer_handshake_key)) return; - if (!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)) { + bool valid; + if (has_field(handshake, RECORD_HANDSHAKE_MAC, HASHBYTES)) { + uint8_t mac[HASHBYTES]; + memcpy(mac, handshake->records[RECORD_HANDSHAKE_MAC].data, HASHBYTES); + memset(handshake->records[RECORD_HANDSHAKE_MAC].data, 0, HASHBYTES); + + valid = fastd_hmacsha256_verify(mac, peer->protocol_state->shared_handshake_key.w, handshake->buffer.data+3, handshake->buffer.len-3); + } + 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; } @@ -593,10 +637,6 @@ static fastd_peer_t* match_sender_key(fastd_context_t *ctx, const fastd_socket_t return peer; } -static inline bool has_field(const fastd_handshake_t *handshake, uint8_t type, size_t length) { - return (handshake->records[type].length == length); -} - 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); @@ -722,9 +762,11 @@ static void protocol_handshake_handle(fastd_context_t *ctx, fastd_socket_t *sock return; } - if (!has_field(handshake, RECORD_T, HASHBYTES)) { - pr_debug(ctx, "received handshake reply without HMAC from %P[%I]", peer, remote_addr); - return; + if (!has_field(handshake, RECORD_HANDSHAKE_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; |