update proposed new wire protocol docs

docs/wire-protocol.txt

@@ -11,96 +11,79 @@ datagram based network layer.
 
 outer message format:
 
-{
-  A: command,
-  B: <16 bytes flow id>,
-  C: <optional 32 bytes cookie>,
-  X: <N bytes payload>
-}
+outer-header:
 
-comamnds:
+<1 byte command>
+<1 byte reserved, R, set to '=' (0x3d)>
+<32 bytes flow id, B>
 
-A - get handshake cookie
 
-obtain a handshake cookie
+command 'O' - obtain flow id
 
-B is randomized
-X MUST contain the user agent string of the requester.
+obtain a handshake cookie
 
-the if the network id differs from the current network's id a reject message is
-sent:
+<outer-header>
+<32 bytes random>
+<8 bytes net id>
+<remaining discarded>
 
-{
-  A: R,
-  B: msg.B,
-  X: "<reply line>"
-}
+the if the network id differs from the current network's id a reject message
+MUST be sent
 
 MUST be replied to with a message rejected or a give handshake cookie
 
-C - give handshake cookie
+command 'G' - give flow id
 
-give a handshake cookie to a remote endpoint that asks for one
+<outer-header>
+<32 byte new flow-id, X>
+<remaining discarded>
 
-B is the B value from the get handshake cookie message
-X is a 32 byte handshake cookie, calcuated via:
-
-r = RAND(32)
-a = "<ascii representation of ip>" + " " + "<port number>"
-X = HS(a + B + r)
+give a flow id to a remote endpoint that asks for one
 
-R - message rejected
+B is the B value from the request flow id message
+X is a 32 byte the flow id, calcuated via:
 
-B is the flow id from the recipiant
-X is a reply line
+r = RAND(32)
+a = "::ffff.<ascii representation of ipv4 address>" + ":" + "<port number>"
+X = HS(a + B + r + net id)
 
-reject a message with flow id B
+resulting message:
 
-S - session negotiation
+  "G=<32 byte flowid><32 bytes new flowid>"
 
-negotiate encrypted session 
+after recieving a give flow id message a session negotiation can happen
 
-B is the flow id from the recipiant
-C is the handshake cookie
-X is encrypted session negotiation data
+command 'R' - message rejected
 
-D - encrypted data transmission
+<outer-header>
+<N arbitrary bytes reason for rejection>
 
-transmit encrypted data on session
+reject a message on a flow id
 
 B is the flow id from the recipiant
-X is authenticated and encrypted data
-
-BNF:
-
-<reply-line> ::= <status-code> <space> <method> <space> <message>
-
-<status-code> ::= <integer> <digit> <digit>
-
-<word> ::= <letter>+
-
-<message> ::= <word> <space> <word>* | <word>
-
-<method> ::= "COOKIE" | "HANDSHAKE"
 
-<user-agent> ::= <net-id> <space> <protocol-version> <space> <agent-version>
+resulting message of reject with reason "no you"
 
-<net-id> ::= "lokinet" | "testnet"
+  "R=<32 byte flow-id>no you"
 
-<space> ::= " "
+command 'S' - session negotiation
 
-<zero> ::= "0"
-
-<integer> ::= "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9"
-
-<digit> ::= <zero> | <integer>
+negotiate encrypted session 
 
-<number> ::= <zero> | <integer> <digit>*
+<outer-header>
+<24 bytes nounce, N>
+<encrypted session negotiation data, X>
+<last 32 bytes keyed hash, Z>
 
-<agent-version> ::= <number> "." <number> "." <number>
+B is the flow id from the recipiant generated by the give flow id message (from outer header)
+N is a random nounce
+X is encrypted session negotiation data
+Z is a keyed hash
 
-<protocol-version> ::= <number>
+Z is generated via:
 
+msg.Z = '0x00' * 32
+msg.Z = MDS(msg, tx_K)
 
 session negotiation:
 
@@ -119,15 +102,9 @@ a.tx_K = k_b
 b.tx_K = k_a
 
 
-inner message format:
-
-<32 bytes blake2s keyed hash of following data>
-<24 bytes nounce>
-<remaining bytes encrypted payload>
-
 decryption is done via:
 
-SD(remaining, rx_K, nounce)
+SD(msg.X, rx_K, msg.N)
 
 encrypted payload is bencoded LIM (see proto_v0.txt)
 
@@ -147,20 +124,144 @@ b.rx_K = k_b
 a.tx_K = k_b
 b.tx_K = k_a
 
-afterwards data transmission may happen
+afterwards data transmission may happen.
+the intiator's remote address is permitted to change during data transmission.
+remote address of the last successfully 
 
-data tranmission:
+D - encrypted data transmission
 
-message format:
+transmit encrypted data on session
 
-<10 byte header>
-<remaining data payload>
+<outer-header>
+<24 bytes nonce, N>
+<encrypted data, X>
+<last 32 bytes keyed hash of entire payload, Z>
 
-header format:
 
-<1 byte proto version>
+B is the flow id from the recipiant (from outer header)
+N is a random nounce
+X is encrypted data
+Z is keyed hash of entire message
+
+Z is generated via:
+
+msg.Z = '0x00' * 32
+msg.Z = MDS(msg, tx_K)
+
+data tranmission:
+
+inner message format of X (after decryption):
+
+header:
+
+<1 byte protocol version>
 <1 byte command>
-<1 byte flags>
-<1 byte fragno>
-<2 bytes fraglen>
-<4 bytes seqno>
+
+
+command: 'K' (keep alive) 
+
+tell other side to acknoledge they are alive
+
+<header>
+<2 bytes resevered, set to 0>
+<2 bytes attempt counter, set to 0 and incremented every retransmit, reset when we get a keepalive ack>
+<2 bytes milliseconds ping timeout>
+<8 bytes current session TX limit in bytes per second>
+<8 bytes current session RX use in bytes per second>
+<8 bytes milliseconds since epoch our current time>
+<remaining bytes discarded>
+
+command: 'L' (keep alive ack)
+
+acknolege keep alive message
+
+<header>
+<6 bytes reserved, set to 0>
+<8 bytes current session RX limit in bytes per second>
+<8 bytes current session TX use in bytes per second>
+<8 bytes milliseconds since epoch our current time>
+<remaining bytes discarded>
+
+
+command: 'C' (congestion)
+
+tell other side to slow down
+
+<header>
+<2 bytes reduce TX rate by this many 1024 bytes per second>
+<4 bytes milliseconds slowdown lifetime>
+<remaining bytes discarded>
+
+command: 'D' (anti-congestion)
+
+tell other side to speed up
+
+<header>
+<2 bytes increase TX rate by this many 1024 bytes per second>
+<4 bytes milliseconds speedup lifetime>
+<remaining bytes discarded>
+
+command: 'T' (transmit)
+
+transit fragment
+
+<header>
+<1 byte number of 16 byte blocks offset from beginning of message, O>
+<1 byte number of 16 byte blocks size of fragment data, N>
+<4 bytes sequence number>
+<32 bytes expected digest of message, present if O is 0, otherwise omitted>
+<16 * N bytes of data>
+<remaining bytes discarded>
+
+command: 'A' (ack)
+
+acknoledge fragments
+
+<header>
+<1 byte number of acks following, N>
+<8 * N bytes acks>
+<remaining bytes discarded>
+
+ack format:
+
+<4 byte message sequence number>
+<1 byte reserved current set to 0>
+<1 byte ack counter (number of acks sent for the corrisponding message)>
+<1 byte bitmask fragments selective ack (msb is fragment 0, lsb is fragment 7)>
+<1 byte bitmask fragments posative ack (msb is fragment 0, lsb is fragment 7)>
+
+
+command: 'R' (rotate keys)
+
+inform remote that their RX key should be rotated
+
+given alice(A) sends this message to bob(B) the new keys are computed as such:
+
+n_K = TKE(K, B_e, K_seed, N)
+
+A.tx_K = n_K
+B.rx_K = n_K
+
+<2 bytes milliseconds lifetime of old keys, retain them for this long and then discard>
+<4 bytes reserved, set to 0>
+<32 bytes key exchange nounce, N>
+<32 bytes next public encryption key, K>
+<remaining bytes discarded>
+
+command: 'U' (upgrade)
+
+request protocol upgrade
+
+<header>
+<1 byte protocol min version to upgrade to>
+<1 byte protocol max version to upgrade to>
+<remaining bytes discarded>
+
+command: 'V' (version upgrade)
+
+sent in response to upgrade message
+
+<header>
+<1 byte protocol version selected>
+<1 byte protocol version highest we support>
+<remaining bytes discarded>