diff options
Diffstat (limited to 'src/protocol_ec25519_fhmqvc_xsalsa20_poly1305.c')
| -rw-r--r-- | src/protocol_ec25519_fhmqvc_xsalsa20_poly1305.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/src/protocol_ec25519_fhmqvc_xsalsa20_poly1305.c b/src/protocol_ec25519_fhmqvc_xsalsa20_poly1305.c index c729428..d743d9c 100644 --- a/src/protocol_ec25519_fhmqvc_xsalsa20_poly1305.c +++ b/src/protocol_ec25519_fhmqvc_xsalsa20_poly1305.c @@ -58,6 +58,10 @@ #error bug: HASHBYTES != SECRETKEYBYTES #endif +#if crypto_secretbox_xsalsa20poly1305_BOXZEROBYTES > NONCEBYTES +#error bug: crypto_secretbox_xsalsa20poly1305_BOXZEROBYTES > NONCEBYTES +#endif + struct _fastd_protocol_context { ecc_secret_key_256 secret_key; @@ -190,6 +194,14 @@ static size_t protocol_max_packet_size(fastd_context *ctx) { return (fastd_max_packet_size(ctx) - NONCEBYTES); } +static size_t protocol_min_encrypt_head_space(fastd_context *ctx) { + return crypto_secretbox_xsalsa20poly1305_ZEROBYTES; +} + +static size_t protocol_min_decrypt_head_space(fastd_context *ctx) { + return 0; +} + static char* protocol_peer_str(const fastd_context *ctx, const fastd_peer *peer) { char addr_buf[INET6_ADDRSTRLEN] = ""; char *ret; @@ -574,6 +586,29 @@ static void protocol_handle_recv(fastd_context *ctx, fastd_peer *peer, fastd_buf pr_debug(ctx, "received unexpected non-handshake packet from %P", peer); goto end; } + + if (!is_nonce_valid(buffer.data, peer->protocol_state->receive_nonce)) { + pr_debug(ctx, "received packet with invalid nonce from %P", peer); + goto end; + } + + uint8_t nonce[NONCEBYTES]; + memcpy(nonce, buffer.data, NONCEBYTES); + + fastd_buffer_push_head(&buffer, NONCEBYTES-crypto_secretbox_xsalsa20poly1305_BOXZEROBYTES); + memset(buffer.data, 0, crypto_secretbox_xsalsa20poly1305_BOXZEROBYTES); + + fastd_buffer recv_buffer = fastd_buffer_alloc(buffer.len, 0, 0); + + if (crypto_secretbox_xsalsa20poly1305_open(recv_buffer.data, buffer.data, buffer.len, nonce, peer->protocol_state->shared_session_key) != 0) { + pr_debug(ctx, "varification failed for packet received from %P", peer); + goto end; + } + + fastd_buffer_push_head(&recv_buffer, crypto_secretbox_xsalsa20poly1305_ZEROBYTES); + fastd_task_put_handle_recv(ctx, peer, recv_buffer); + + memcpy(peer->protocol_state->receive_nonce, nonce, NONCEBYTES); } end: @@ -581,7 +616,26 @@ static void protocol_handle_recv(fastd_context *ctx, fastd_peer *peer, fastd_buf } static void protocol_send(fastd_context *ctx, fastd_peer *peer, fastd_buffer buffer) { + if (!peer->protocol_state || peer->protocol_state->state != HANDSHAKE_STATE_ESTABLISHED) { + fastd_buffer_free(buffer); + return; + } + + fastd_buffer_pull_head(&buffer, crypto_secretbox_xsalsa20poly1305_ZEROBYTES); + memset(buffer.data, 0, crypto_secretbox_xsalsa20poly1305_ZEROBYTES); + + fastd_buffer send_buffer = fastd_buffer_alloc(buffer.len, NONCEBYTES-crypto_secretbox_xsalsa20poly1305_BOXZEROBYTES, 0); + + crypto_secretbox_xsalsa20poly1305(send_buffer.data, buffer.data, buffer.len, peer->protocol_state->send_nonce, peer->protocol_state->shared_session_key); + fastd_buffer_free(buffer); + + fastd_buffer_pull_head(&send_buffer, NONCEBYTES-crypto_secretbox_xsalsa20poly1305_BOXZEROBYTES); + memcpy(send_buffer.data, peer->protocol_state->send_nonce, NONCEBYTES); + + fastd_task_put_send(ctx, peer, send_buffer); + + increment_nonce(peer->protocol_state->send_nonce); } static void protocol_free_peer_state(fastd_context *ctx, fastd_peer *peer) { @@ -595,6 +649,8 @@ const fastd_protocol fastd_protocol_ec25519_fhmqvc_xsalsa20_poly1305 = { .init = protocol_init, .max_packet_size = protocol_max_packet_size, + .min_encrypt_head_space = protocol_min_encrypt_head_space, + .min_decrypt_head_space = protocol_min_decrypt_head_space, .peer_str = protocol_peer_str, |