dash/dash-docs/protocol-documentation.md

Protocol Documentation - 0.12.1

This document describes the protocol extensions for all additional functionality build into the Dash protocol. This doesn't include any of the Bitcoin procotol, which has been left in tact in the Dash project. For more information about the core protocol, please see https://en.bitcoin.it/w/index.php?title#Protocol_documentation&action#edit

Common Structures

Simple types

uint256 => char[32]

CScript => uchar[]

COutpoint

Bitcoin Input

Field Size	Description	Data type	Comments
32	hash	uint256	Hash of transactional output which is being referenced
4	n	uint32_t	Index of transaction which is being referenced

CTXIn

Bitcoin Input

Field Size	Description	Data type	Comments
36	prevout	COutPoint	The previous output from an existing transaction, in the form of an unspent output
1+	script length	var_int	The length of the signature script
?	script	CScript	The script which is validated for this input to be spent
4	nSequence	uint_32t	Transaction version as defined by the sender. Intended for "replacement" of transactions when information is updated before inclusion into a block.

CPubkey

Bitcoin Public Key

Field Size	Description	Data type	Comments
33-65	vch	char[]	Encapcilated public key of masternode in serialized varchar form

Masternode Winner

When a new block is found on the network, a masternode quorum will be determined and those 10 selected masternodes will issue a masternode winner command to pick the next winning node.

Field Size	Description	Data type	Comments
41+	vinMasternode	CTXIn	The unspent output of the masternode which is signing the message
4	nBlockHeight	int	The blockheight which the payee should be paid
?	payeeAddress	CScript	The address to pay to
71-73	sig	char[]	Signature of the masternode)

Message Types

Masternode Winner

When a new block is found on the network, a masternode quorum will be determined and those 10 selected masternodes will issue a masternode winner command to pick the next winning node.

Field Size	Description	Data type	Comments
41+	vinMasternode	CTXIn	The unspent output of the masternode which is signing the message
4	nBlockHeight	int	The blockheight which the payee should be paid
?	payeeAddress	CScript	The address to pay to
71-73	sig	char[]	Signature of the masternode)

Governance Vote

Masternodes use governance voting in response to new proposals, contracts, settings or finalized budgets.

Field Size	Description	Data type	Comments
41+	Unspent Output	CTXIn	Unspent output for the masternode which is voting
32	nParentHash	uint256	Object which we're voting on (proposal, contract, setting or final budget)
4	nVote	int	Yes (1), No(2) or Abstain(0)
8	nTime	int_64t	Time which the vote was created
71-73	vchSig	char[]	Signature of the masternode

Governance Object

A proposal, contract or setting.

Field Size	Description	Data type	Comments
1-20	strName	std::string	Name of the governance object
1-64	strURL	std::string	URL where detailed information about the governance object can be found
8	nTime	int_64t	Time which this object was created
4	nBlockStart	int	Starting block, which the first payment will occur
4	nBlockEnd	int	Ending block, which the last payment will occur
8	nAmount	int_64t	The amount in satoshi's that will be paid out each time
?	payee	CScript	Address which will be paid out to
32	nFeeTXHash	uint256	Hash of the collateral fee transaction

Finalized Budget

Contains a finalized list of the order in which the next budget will be paid.

Field Size	Description	Data type	Comments
41+	strBudgetName	CTXIn	The unspent output of the masternode which is signing the message
4	nBlockStart	int	The blockheight which the payee should be paid
?	vecBudgetPayments	CScript	The address to pay to
32	nFeeTXHash	uint256	Hash of the collateral fee transaction

Masternode Announce

Whenever a masternode comes online or a client is syncing, they will send this message which describes the masternode entry and how to validate messages from it.

Field Size	Description	Data type	Comments
41+	vin	CTXIn	The unspent output of the masternode which is signing the message
#	addr	CService	Address of the main 1000 DASH unspent output
33-65	pubkey	CPubkey	CPubKey of the main 1000 DASH unspent output
33-65	pubkey2	CPubkey	CPubkey of the secondary signing key (For all other messaging other than announce message)
71-73	sig	char[]	Signature of this message
8	sigTime	int_64t	Time which the signature was created
4	protocolVersion	int	The protocol version of the masternode
#	lastPing	CMastenrodePing	The last time the masternode pinged the network
8	nLastDsq	int_64t	The last time the masternode sent a DSQ message (for darksend mixing)

Masternode Ping

CMastenrodePing

Every few minutes, masternodes ping the network with a message that propagates the whole network.

Field Size	Description	Data type	Comments
41+	vin	CTXIn	The unspent output of the masternode which is signing the message
32	blockHash	uint256	Current chaintip blockhash minus 12
8	sigTime	int_64t	Signature time for this ping
71-73	vchSig	char[]	Signature of this message by masternode (verifiable via pubkey2)

Masternode DSTX

Masternodes can broadcast subsidised transactions without fees for the sake of security in Darksend. This is done via the DSTX message.

Field Size	Description	Data type	Comments
#	tx	CTransaction	The unspent output of the masternode which is signing the message
41+	vin	CTXIn	Masternode unspent output
71-73	vchSig	char[]	Signature of this message by masternode (verifiable via pubkey2)
8	sigTime	int_64_t	Time this message was signed

DSSTATUSUPDATE - DSSU

Darksend pool status update

Field Size	Description	Data type	Comments
4	sessionID	int	The unspent output of the masternode which is signing the message
4	GetState	int	Masternode unspent output
4	GetEntriesCount	int	Number of entries
4	Status	int	Status of the mixing process
4	errorID	int	Error ID if any

DSSTATUSUPDATE - DSQ

Asks users to sign final Darksend tx message.

Field Size	Description	Data type	Comments
4	vDenom	int	Which denominations are allowed in this mixing session
4	vin	int	unspend output from masternode which is hosting this session
4	time	int	the time this DSQ was created
4	ready	int	if the mixing pool is ready to be executed
71-73	vchSig	char[]	Signature of this message by masternode (verifiable via pubkey2)

DSSTATUSUPDATE - DSA

Response to DSQ message which allows the user to join a Darksend mixing pool

Field Size	Description	Data type	Comments
4	sessionDenom	int	denomination that will be exclusively used when submitting inputs into the pool
4	txCollateral	int	unspend output from masternode which is hosting this session

DSSTATUSUPDATE - DSS

User's signed inputs for a group transaction in a Darksend session

Field Size	Description	Data type	Comments
#	inputs	CTXIn[]	signed inputs for Darksend session