diff options
| -rw-r--r-- | src/handshake.c | 68 | ||||
| -rw-r--r-- | src/handshake.h | 65 | ||||
| -rw-r--r-- | src/protocols/ec25519_fhmqvc/handshake.c | 24 | ||||
| -rw-r--r-- | src/types.h | 1 |
4 files changed, 101 insertions, 57 deletions
diff --git a/src/handshake.c b/src/handshake.c index a55844f..7dd5b44 100644 --- a/src/handshake.c +++ b/src/handshake.c @@ -78,8 +78,11 @@ static inline uint32_t as_uint32(const fastd_handshake_record_t *record) { } /** Reads a TLV record as a 16bit integer (little endian) */ -static inline uint16_t as_uint16_le(const fastd_handshake_record_t *record) { - return as_uint8(record) | (uint16_t)record->data[1] << 8; +static inline uint16_t as_uint16_endian(const fastd_handshake_record_t *record, bool little_endian) { + if (little_endian) + return as_uint8(record) | (uint16_t)record->data[1] << 8; + else + return as_uint16(record); } /** Reads a TLV record as a variable-length integer (little endian) */ @@ -157,7 +160,7 @@ static fastd_string_stack_t * parse_string_list(const uint8_t *data, size_t len) } /** Allocates and initializes a new handshake packet */ -static fastd_buffer_t new_handshake(uint8_t type, const fastd_method_info_t *method, bool with_method_list, size_t tail_space) { +static fastd_handshake_buffer_t new_handshake(uint8_t type, bool little_endian, const fastd_method_info_t *method, bool with_method_list, size_t tail_space) { size_t version_len = strlen(FASTD_VERSION); size_t protocol_len = strlen(conf.protocol->name); size_t method_len = method ? strlen(method->name) : 0; @@ -168,22 +171,24 @@ static fastd_buffer_t new_handshake(uint8_t type, const fastd_method_info_t *met if (with_method_list) method_list = create_method_list(&method_list_len); - fastd_buffer_t buffer = fastd_buffer_alloc(sizeof(fastd_handshake_packet_t), 1, - 3*5 + /* handshake type, mode, reply code */ - 6 + /* MTU */ - 4+version_len + /* version name */ - 4+protocol_len + /* protocol name */ - 4+method_len + /* method name */ - 4+method_list_len + /* supported method name list */ - tail_space); - fastd_handshake_packet_t *packet = buffer.data; + fastd_handshake_buffer_t buffer = { + .buffer = fastd_buffer_alloc(sizeof(fastd_handshake_packet_t), 1, + 3*5 + /* handshake type, mode, reply code */ + 6 + /* MTU */ + 4+version_len + /* version name */ + 4+protocol_len + /* protocol name */ + 4+method_len + /* method name */ + 4+method_list_len + /* supported method name list */ + tail_space), + .little_endian = little_endian}; + fastd_handshake_packet_t *packet = buffer.buffer.data; packet->rsv = 0; packet->tlv_len = 0; fastd_handshake_add_uint8(&buffer, RECORD_HANDSHAKE_TYPE, type); fastd_handshake_add_uint8(&buffer, RECORD_MODE, conf.mode); - fastd_handshake_add_uint16_le(&buffer, RECORD_MTU, conf.mtu); + fastd_handshake_add_uint16_endian(&buffer, RECORD_MTU, conf.mtu); fastd_handshake_add(&buffer, RECORD_VERSION_NAME, version_len, FASTD_VERSION); fastd_handshake_add(&buffer, RECORD_PROTOCOL_NAME, protocol_len, conf.protocol->name); @@ -200,13 +205,13 @@ static fastd_buffer_t new_handshake(uint8_t type, const fastd_method_info_t *met } /** Allocates and initializes a new initial handshake packet */ -fastd_buffer_t fastd_handshake_new_init(size_t tail_space) { - return new_handshake(1, NULL, !conf.secure_handshakes, tail_space); +fastd_handshake_buffer_t fastd_handshake_new_init(size_t tail_space) { + return new_handshake(1, true, NULL, !conf.secure_handshakes, tail_space); } /** Allocates and initializes a new reply handshake packet */ -fastd_buffer_t fastd_handshake_new_reply(uint8_t type, const fastd_method_info_t *method, bool with_method_list, size_t tail_space) { - fastd_buffer_t buffer = new_handshake(type, method, with_method_list, tail_space); +fastd_handshake_buffer_t fastd_handshake_new_reply(uint8_t type, bool little_endian, const fastd_method_info_t *method, bool with_method_list, size_t tail_space) { + fastd_handshake_buffer_t buffer = new_handshake(type, little_endian, method, with_method_list, tail_space); fastd_handshake_add_uint8(&buffer, RECORD_REPLY_CODE, 0); return buffer; } @@ -258,8 +263,11 @@ static void print_error(const char *prefix, const fastd_peer_address_t *remote_a static void send_error(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, uint8_t reply_code, uint16_t error_detail) { print_error("sending", remote_addr, reply_code, error_detail); - fastd_buffer_t buffer = fastd_buffer_alloc(sizeof(fastd_handshake_packet_t), 0, 3*5 /* enough space for handshake type, reply code and error detail */); - fastd_handshake_packet_t *reply = buffer.data; + fastd_handshake_buffer_t buffer = { + .buffer = fastd_buffer_alloc(sizeof(fastd_handshake_packet_t), 0, 3*5 /* enough space for handshake type, reply code and error detail */), + .little_endian = handshake->little_endian + }; + fastd_handshake_packet_t *reply = buffer.buffer.data; reply->rsv = 0; reply->tlv_len = 0; @@ -268,7 +276,7 @@ static void send_error(fastd_socket_t *sock, const fastd_peer_address_t *local_a fastd_handshake_add_uint8(&buffer, RECORD_REPLY_CODE, reply_code); fastd_handshake_add_uint(&buffer, RECORD_ERROR_DETAIL, error_detail); - fastd_send_handshake(sock, local_addr, remote_addr, peer, buffer); + fastd_send_handshake(sock, local_addr, remote_addr, peer, buffer.buffer); } /** Parses the TLV records of a handshake */ @@ -297,8 +305,20 @@ static inline fastd_handshake_t parse_tlvs(const fastd_buffer_t *buffer) { if (ptr+4 > end) break; - uint16_t type = ptr[0] + (ptr[1] << 8); - uint16_t len = ptr[2] + (ptr[3] << 8); + uint16_t type, len; + + if (!handshake.little_endian) { + type = ptr[1] + (ptr[0] << 8); + len = ptr[3] + (ptr[2] << 8); + + if (type > 0xff || (type == 0 && len > 0xff)) + handshake.little_endian = true; + } + + if (handshake.little_endian) { + type = ptr[0] + (ptr[1] << 8); + len = ptr[2] + (ptr[3] << 8); + } if (ptr+4+len > end) break; @@ -343,9 +363,9 @@ static inline bool check_records(fastd_socket_t *sock, const fastd_peer_address_ if (!conf.secure_handshakes || handshake->type > 1) { if (handshake->records[RECORD_MTU].length == 2) { - if (as_uint16_le(&handshake->records[RECORD_MTU]) != conf.mtu) { + if (as_uint16_endian(&handshake->records[RECORD_MTU], handshake->little_endian) != conf.mtu) { pr_warn("MTU configuration differs with peer %I: local MTU is %u, remote MTU is %u", - remote_addr, conf.mtu, as_uint16_le(&handshake->records[RECORD_MTU])); + remote_addr, conf.mtu, as_uint16_endian(&handshake->records[RECORD_MTU], handshake->little_endian)); } } } diff --git a/src/handshake.h b/src/handshake.h index 760d21b..f5582e9 100644 --- a/src/handshake.h +++ b/src/handshake.h @@ -89,11 +89,18 @@ struct fastd_handshake { fastd_handshake_record_t records[RECORD_MAX]; /**< The TLV records of the handshake */ uint16_t tlv_len; /**< The length of the TLV record data */ void *tlv_data; /**< TLV record data */ + bool little_endian; /**< true if the old little-endian handshake format is used */ +}; + +/** A buffer a handshake to send is prepared in */ +struct fastd_handshake_buffer { + fastd_buffer_t buffer; + bool little_endian; }; -fastd_buffer_t fastd_handshake_new_init(size_t tail_space); -fastd_buffer_t fastd_handshake_new_reply(uint8_t type, const fastd_method_info_t *method, bool with_method_list, size_t tail_space); +fastd_handshake_buffer_t fastd_handshake_new_init(size_t tail_space); +fastd_handshake_buffer_t fastd_handshake_new_reply(uint8_t type, bool little_endian, const fastd_method_info_t *method, bool with_method_list, size_t tail_space); void fastd_handshake_handle(fastd_socket_t *sock, const fastd_peer_address_t *local_addr, const fastd_peer_address_t *remote_addr, fastd_peer_t *peer, fastd_buffer_t buffer); @@ -111,34 +118,42 @@ static inline uint16_t fastd_handshake_tlv_len(const fastd_buffer_t *buffer) { } /** Adds an uninitialized TLV record of given type and length to a handshake buffer */ -static inline uint8_t * fastd_handshake_extend(fastd_buffer_t *buffer, fastd_handshake_record_type_t type, size_t len) { - uint8_t *dst = buffer->data + buffer->len; +static inline uint8_t * fastd_handshake_extend(fastd_handshake_buffer_t *buffer, fastd_handshake_record_type_t type, size_t len) { + uint8_t *dst = buffer->buffer.data + buffer->buffer.len; - if (buffer->data + buffer->len + 4 + len > buffer->base + buffer->base_len) + if (buffer->buffer.data + buffer->buffer.len + 4 + len > buffer->buffer.base + buffer->buffer.base_len) exit_bug("not enough buffer allocated for handshake"); - buffer->len += 4 + len; + buffer->buffer.len += 4 + len; - fastd_handshake_packet_t *packet = buffer->data; - packet->tlv_len = htons(fastd_handshake_tlv_len(buffer) + 4 + len); + fastd_handshake_packet_t *packet = buffer->buffer.data; + packet->tlv_len = htons(fastd_handshake_tlv_len(&buffer->buffer) + 4 + len); - dst[0] = type; - dst[1] = type >> 8; - dst[2] = len; - dst[3] = len >> 8; + if (buffer->little_endian) { + dst[0] = type; + dst[1] = type >> 8; + dst[2] = len; + dst[3] = len >> 8; + } + else { + dst[0] = type >> 8; + dst[1] = type; + dst[2] = len >> 8; + dst[3] = len; + } return dst+4; } /** Adds an TLV record of given type and length initialized with arbitraty data to a handshake buffer */ -static inline void fastd_handshake_add(fastd_buffer_t *buffer, fastd_handshake_record_type_t type, size_t len, const void *data) { +static inline void fastd_handshake_add(fastd_handshake_buffer_t *buffer, fastd_handshake_record_type_t type, size_t len, const void *data) { uint8_t *dst = fastd_handshake_extend(buffer, type, len); memcpy(dst, data, len); } /** Adds an TLV record of given type and length initialized with zeros to a handshake buffer */ -static inline uint8_t * fastd_handshake_add_zero(fastd_buffer_t *buffer, fastd_handshake_record_type_t type, size_t len) { +static inline uint8_t * fastd_handshake_add_zero(fastd_handshake_buffer_t *buffer, fastd_handshake_record_type_t type, size_t len) { uint8_t *dst = fastd_handshake_extend(buffer, type, len); memset(dst, 0, len); @@ -146,14 +161,14 @@ static inline uint8_t * fastd_handshake_add_zero(fastd_buffer_t *buffer, fastd_h } /** Adds an uint8 TLV record of given type and value to a handshake buffer */ -static inline void fastd_handshake_add_uint8(fastd_buffer_t *buffer, fastd_handshake_record_type_t type, uint8_t value) { +static inline void fastd_handshake_add_uint8(fastd_handshake_buffer_t *buffer, fastd_handshake_record_type_t type, uint8_t value) { uint8_t *dst = fastd_handshake_extend(buffer, type, 1); dst[0] = value; } /** Adds an uint16 TLV record of given type and value to a handshake buffer */ -static inline void fastd_handshake_add_uint16(fastd_buffer_t *buffer, fastd_handshake_record_type_t type, uint16_t value) { +static inline void fastd_handshake_add_uint16(fastd_handshake_buffer_t *buffer, fastd_handshake_record_type_t type, uint16_t value) { uint8_t *dst = fastd_handshake_extend(buffer, type, 2); dst[0] = value >> 8; @@ -161,7 +176,7 @@ static inline void fastd_handshake_add_uint16(fastd_buffer_t *buffer, fastd_hand } /** Adds an uint24 TLV record of given type and value to a handshake buffer */ -static inline void fastd_handshake_add_uint24(fastd_buffer_t *buffer, fastd_handshake_record_type_t type, uint32_t value) { +static inline void fastd_handshake_add_uint24(fastd_handshake_buffer_t *buffer, fastd_handshake_record_type_t type, uint32_t value) { uint8_t *dst = fastd_handshake_extend(buffer, type, 3); dst[0] = value >> 16; @@ -170,7 +185,7 @@ static inline void fastd_handshake_add_uint24(fastd_buffer_t *buffer, fastd_hand } /** Adds an uint32 TLV record of given type and value to a handshake buffer */ -static inline void fastd_handshake_add_uint32(fastd_buffer_t *buffer, fastd_handshake_record_type_t type, uint32_t value) { +static inline void fastd_handshake_add_uint32(fastd_handshake_buffer_t *buffer, fastd_handshake_record_type_t type, uint32_t value) { uint8_t *dst = fastd_handshake_extend(buffer, type, 4); dst[0] = value >> 24; @@ -180,15 +195,21 @@ static inline void fastd_handshake_add_uint32(fastd_buffer_t *buffer, fastd_hand } /** Adds an uint16 TLV record of given type and value to a handshake buffer encoded as little endian */ -static inline void fastd_handshake_add_uint16_le(fastd_buffer_t *buffer, fastd_handshake_record_type_t type, uint16_t value) { +static inline void fastd_handshake_add_uint16_endian(fastd_handshake_buffer_t *buffer, fastd_handshake_record_type_t type, uint16_t value) { uint8_t *dst = fastd_handshake_extend(buffer, type, 2); - dst[0] = value; - dst[1] = value >> 8; + if (buffer->little_endian) { + dst[0] = value; + dst[1] = value >> 8; + } + else { + dst[0] = value >> 8; + dst[1] = value; + } } /** Adds an TLV record of given type and value to a handshake buffer, automatically using a 1- to 4-byte value */ -static inline void fastd_handshake_add_uint(fastd_buffer_t *buffer, fastd_handshake_record_type_t type, uint32_t value) { +static inline void fastd_handshake_add_uint(fastd_handshake_buffer_t *buffer, fastd_handshake_record_type_t type, uint32_t value) { if (value > 0xffffff) fastd_handshake_add_uint32(buffer, type, value); if (value > 0xffff) diff --git a/src/protocols/ec25519_fhmqvc/handshake.c b/src/protocols/ec25519_fhmqvc/handshake.c index 5d3e57e..0b547f4 100644 --- a/src/protocols/ec25519_fhmqvc/handshake.c +++ b/src/protocols/ec25519_fhmqvc/handshake.c @@ -329,7 +329,7 @@ static void clear_shared_handshake_key(const fastd_peer_t *peer) { /** Sends a reply to an initial handshake (type 1) */ static void respond_handshake(const fastd_socket_t *sock, const fastd_peer_address_t *local_addr, const fastd_peer_address_t *remote_addr, fastd_peer_t *peer, - const aligned_int256_t *peer_handshake_key, const fastd_method_info_t *method) { + const aligned_int256_t *peer_handshake_key, const fastd_method_info_t *method, bool little_endian) { pr_debug("responding handshake with %P[%I]...", peer, remote_addr); const handshake_key_t *handshake_key = &ctx.protocol_state->handshake_key; @@ -337,7 +337,7 @@ static void respond_handshake(const fastd_socket_t *sock, const fastd_peer_addre if (!update_shared_handshake_key(peer, handshake_key, peer_handshake_key)) return; - fastd_buffer_t buffer = fastd_handshake_new_reply(2, method, true, 4*(4+PUBLICKEYBYTES) + 2*(4+HASHBYTES)); + fastd_handshake_buffer_t buffer = fastd_handshake_new_reply(2, little_endian, method, true, 4*(4+PUBLICKEYBYTES) + 2*(4+HASHBYTES)); fastd_handshake_add(&buffer, RECORD_SENDER_KEY, PUBLICKEYBYTES, &conf.protocol_config->key.public); fastd_handshake_add(&buffer, RECORD_RECIPIENT_KEY, PUBLICKEYBYTES, &peer->key->key); @@ -352,10 +352,10 @@ static void respond_handshake(const fastd_socket_t *sock, const fastd_peer_addre } uint8_t *mac = fastd_handshake_add_zero(&buffer, RECORD_TLV_MAC, HASHBYTES); - fastd_hmacsha256(&hmacbuf, peer->protocol_state->shared_handshake_key.w, fastd_handshake_tlv_data(&buffer), fastd_handshake_tlv_len(&buffer)); + fastd_hmacsha256(&hmacbuf, peer->protocol_state->shared_handshake_key.w, fastd_handshake_tlv_data(&buffer.buffer), fastd_handshake_tlv_len(&buffer.buffer)); memcpy(mac, hmacbuf.b, HASHBYTES); - fastd_send_handshake(sock, local_addr, remote_addr, peer, buffer); + fastd_send_handshake(sock, local_addr, remote_addr, peer, buffer.buffer); } /** Sends a reply to a handshake response (type 2) */ @@ -398,7 +398,7 @@ static void finish_handshake(fastd_socket_t *sock, const fastd_peer_address_t *l &peer->key->key, &sigma, compat ? NULL : shared_handshake_key.w, handshake_key->serial)) return; - fastd_buffer_t buffer = fastd_handshake_new_reply(3, method, false, 4*(4+PUBLICKEYBYTES) + 2*(4+HASHBYTES)); + fastd_handshake_buffer_t buffer = fastd_handshake_new_reply(3, handshake->little_endian, method, false, 4*(4+PUBLICKEYBYTES) + 2*(4+HASHBYTES)); fastd_handshake_add(&buffer, RECORD_SENDER_KEY, PUBLICKEYBYTES, &conf.protocol_config->key.public); fastd_handshake_add(&buffer, RECORD_RECIPIENT_KEY, PUBLICKEYBYTES, &peer->key->key); @@ -408,7 +408,7 @@ static void finish_handshake(fastd_socket_t *sock, const fastd_peer_address_t *l if (!compat) { fastd_sha256_t hmacbuf; uint8_t *mac = fastd_handshake_add_zero(&buffer, RECORD_TLV_MAC, HASHBYTES); - fastd_hmacsha256(&hmacbuf, shared_handshake_key.w, fastd_handshake_tlv_data(&buffer), fastd_handshake_tlv_len(&buffer)); + fastd_hmacsha256(&hmacbuf, shared_handshake_key.w, fastd_handshake_tlv_data(&buffer.buffer), fastd_handshake_tlv_len(&buffer.buffer)); memcpy(mac, hmacbuf.b, HASHBYTES); } else { @@ -417,7 +417,7 @@ static void finish_handshake(fastd_socket_t *sock, const fastd_peer_address_t *l fastd_handshake_add(&buffer, RECORD_T, HASHBYTES, hmacbuf.b); } - fastd_send_handshake(sock, local_addr, remote_addr, peer, buffer); + fastd_send_handshake(sock, local_addr, remote_addr, peer, buffer.buffer); } /** Handles a reply to a handshake response (type 3) */ @@ -521,7 +521,7 @@ static fastd_peer_t * match_sender_key(const fastd_socket_t *sock, const fastd_p void fastd_protocol_ec25519_fhmqvc_handshake_init(fastd_socket_t *sock, const fastd_peer_address_t *local_addr, const fastd_peer_address_t *remote_addr, fastd_peer_t *peer) { fastd_protocol_ec25519_fhmqvc_maintenance(); - fastd_buffer_t buffer = fastd_handshake_new_init(3*(4+PUBLICKEYBYTES) /* sender key, recipient key, handshake key */); + fastd_handshake_buffer_t buffer = fastd_handshake_new_init(3*(4+PUBLICKEYBYTES) /* sender key, recipient key, handshake key */); fastd_handshake_add(&buffer, RECORD_SENDER_KEY, PUBLICKEYBYTES, &conf.protocol_config->key.public); @@ -539,7 +539,7 @@ void fastd_protocol_ec25519_fhmqvc_handshake_init(fastd_socket_t *sock, const fa if (!peer || !fastd_peer_is_established(peer)) fastd_peer_exec_shell_command(&conf.on_connect, peer, (local_addr && local_addr->sa.sa_family) ? local_addr : sock->bound_addr, remote_addr); - fastd_send_handshake(sock, local_addr, remote_addr, peer, buffer); + fastd_send_handshake(sock, local_addr, remote_addr, peer, buffer.buffer); } @@ -557,6 +557,7 @@ static inline void print_unknown_key(const fastd_peer_address_t *addr, const uns /** Data attached to an asynchronous on-verify run */ typedef struct verify_data { aligned_int256_t peer_handshake_key; /**< The public key of the peer being verified */ + bool little_endian; /**< The handshake endianess */ } verify_data_t; /** Adds a dynamic peer for an unknown key */ @@ -614,6 +615,7 @@ static bool handle_dynamic(fastd_socket_t *sock, const fastd_peer_address_t *loc verify_data_t verify_data; memset(&verify_data, 0, sizeof(verify_data)); memcpy(&verify_data.peer_handshake_key, handshake->records[RECORD_SENDER_HANDSHAKE_KEY].data, PUBLICKEYBYTES); + verify_data.little_endian = handshake->little_endian; fastd_tristate_t verified = fastd_verify_peer(peer, sock, local_addr, remote_addr, method, &verify_data, sizeof(verify_data)); @@ -640,7 +642,7 @@ void fastd_protocol_ec25519_fhmqvc_handle_verify_return(fastd_peer_t *peer, fast peer->last_handshake_response_timeout = ctx.now + MIN_HANDSHAKE_INTERVAL; peer->last_handshake_response_address = *remote_addr; - respond_handshake(sock, local_addr, remote_addr, peer, &data->peer_handshake_key, method); + respond_handshake(sock, local_addr, remote_addr, peer, &data->peer_handshake_key, method, data->little_endian); } #else @@ -726,7 +728,7 @@ void fastd_protocol_ec25519_fhmqvc_handshake_handle(fastd_socket_t *sock, const peer->last_handshake_response_timeout = ctx.now + MIN_HANDSHAKE_INTERVAL; peer->last_handshake_response_address = *remote_addr; - respond_handshake(sock, local_addr, remote_addr, peer, &peer_handshake_key, method); + respond_handshake(sock, local_addr, remote_addr, peer, &peer_handshake_key, method, handshake->little_endian); return; } diff --git a/src/types.h b/src/types.h index d0a0221..01b36f5 100644 --- a/src/types.h +++ b/src/types.h @@ -107,6 +107,7 @@ typedef struct fastd_mac_info fastd_mac_info_t; typedef struct fastd_mac fastd_mac_t; typedef struct fastd_handshake fastd_handshake_t; +typedef struct fastd_handshake_buffer fastd_handshake_buffer_t; typedef struct fastd_lex fastd_lex_t; typedef struct fastd_parser_state fastd_parser_state_t; |