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// Copyright (c) 2014-2016 The btcsuite developers
// Copyright (c) 2015-2018 The Decred developers
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package chaincfg
import (
"encoding/hex"
"errors"
"fmt"
"math/big"
"time"
"github.com/decred/dcrd/chaincfg/chainhash"
"github.com/decred/dcrd/wire"
)
// These variables are the chain proof-of-work limit parameters for each default
// network.
var (
// bigOne is 1 represented as a big.Int. It is defined here to avoid
// the overhead of creating it multiple times.
bigOne = big.NewInt(1)
// mainPowLimit is the highest proof of work value a Decred block can
// have for the main network. It is the value 2^224 - 1.
mainPowLimit = new(big.Int).Sub(new(big.Int).Lsh(bigOne, 224), bigOne)
// testNetPowLimit is the highest proof of work value a Decred block
// can have for the test network. It is the value 2^232 - 1.
testNetPowLimit = new(big.Int).Sub(new(big.Int).Lsh(bigOne, 232), bigOne)
// simNetPowLimit is the highest proof of work value a Decred block
// can have for the simulation test network. It is the value 2^255 - 1.
simNetPowLimit = new(big.Int).Sub(new(big.Int).Lsh(bigOne, 255), bigOne)
VoteBitsNotFound = fmt.Errorf("vote bits not found")
)
// SigHashOptimization is an optimization for verification of transactions that
// do CHECKSIG operations with hashType SIGHASH_ALL. Although there should be no
// consequences to daemons that are simply running a node, it may be the case
// that you could cause database corruption if you turn this code on, create and
// manipulate your own MsgTx, then include them in blocks. For safety, if you're
// using the daemon with wallet or mining with the daemon this should be disabled.
// If you believe that any MsgTxs in your daemon will be used mutably, do NOT
// turn on this feature. It is disabled by default.
// This feature is considered EXPERIMENTAL, enable at your own risk!
var SigHashOptimization = false
// CheckForDuplicateHashes checks for duplicate hashes when validating blocks.
// Because of the rule inserting the height into the second (nonce) txOut, there
// should never be a duplicate transaction hash that overwrites another. However,
// because there is a 2^128 chance of a collision, the paranoid user may wish to
// turn this feature on.
var CheckForDuplicateHashes = false
// CPUMinerThreads is the default number of threads to utilize with the
// CPUMiner when mining.
var CPUMinerThreads = 1
// Checkpoint identifies a known good point in the block chain. Using
// checkpoints allows a few optimizations for old blocks during initial download
// and also prevents forks from old blocks.
//
// Each checkpoint is selected based upon several factors. See the
// documentation for chain.IsCheckpointCandidate for details on the selection
// criteria.
type Checkpoint struct {
Height int64
Hash *chainhash.Hash
}
// Vote describes a voting instance. It is self-describing so that the UI can
// be directly implemented using the fields. Mask determines which bits can be
// used. Bits are enumerated and must be consecutive. Each vote requires one
// and only one abstain (bits = 0) and reject vote (IsNo = true).
//
// For example, change block height from int64 to uint64.
// Vote {
// Id: "blockheight",
// Description: "Change block height from int64 to uint64"
// Mask: 0x0006,
// Choices: []Choice{
// {
// Id: "abstain",
// Description: "abstain voting for change",
// Bits: 0x0000,
// IsAbstain: true,
// IsNo: false,
// },
// {
// Id: "no",
// Description: "reject changing block height to uint64",
// Bits: 0x0002,
// IsAbstain: false,
// IsNo: false,
// },
// {
// Id: "yes",
// Description: "accept changing block height to uint64",
// Bits: 0x0004,
// IsAbstain: false,
// IsNo: true,
// },
// },
// }
//
type Vote struct {
// Single unique word identifying the vote.
Id string
// Longer description of what the vote is about.
Description string
// Usable bits for this vote.
Mask uint16
Choices []Choice
}
// Choice defines one of the possible Choices that make up a vote. The 0 value
// in Bits indicates the default choice. Care should be taken not to bias a
// vote with the default choice.
type Choice struct {
// Single unique word identifying vote (e.g. yes)
Id string
// Longer description of the vote.
Description string
// Bits used for this vote.
Bits uint16
// This is the abstain choice. By convention this must be the 0 vote
// (abstain) and exist only once in the Vote.Choices array.
IsAbstain bool
// This coince indicates a hard No Vote. By convention this must exist
// only once in the Vote.Choices array.
IsNo bool
}
// VoteIndex compares vote to Choice.Bits and returns the index into the
// Choices array. If the vote is invalid it returns -1.
func (v *Vote) VoteIndex(vote uint16) int {
vote &= v.Mask
for k := range v.Choices {
if vote == v.Choices[k].Bits {
return k
}
}
return -1
}
const (
// VoteIDMaxBlockSize is the vote ID for the the maximum block size
// increase agenda used for the hard fork demo.
VoteIDMaxBlockSize = "maxblocksize"
// VoteIDSDiffAlgorithm is the vote ID for the new stake difficulty
// algorithm (aka ticket price) agenda defined by DCP0001.
VoteIDSDiffAlgorithm = "sdiffalgorithm"
// VoteIDLNSupport is the vote ID for determining if the developers
// should work on integrating Lightning Network support.
VoteIDLNSupport = "lnsupport"
// VoteIDLNFeatures is the vote ID for the agenda that introduces
// features useful for the Lightning Network (among other uses) defined
// by DCP0002 and DCP0003.
VoteIDLNFeatures = "lnfeatures"
)
// ConsensusDeployment defines details related to a specific consensus rule
// change that is voted in. This is part of BIP0009.
type ConsensusDeployment struct {
// Vote describes the what is being voted on and what the choices are.
// This is sitting in a struct in order to make merging between btcd
// easier.
Vote Vote
// StartTime is the median block time after which voting on the
// deployment starts.
StartTime uint64
// ExpireTime is the median block time after which the attempted
// deployment expires.
ExpireTime uint64
}
// TokenPayout is a payout for block 1 which specifies an address and an amount
// to pay to that address in a transaction output.
type TokenPayout struct {
Address string
Amount int64
}
// DNSSeed identifies a DNS seed.
type DNSSeed struct {
// Host defines the hostname of the seed.
Host string
// HasFiltering defines whether the seed supports filtering
// by service flags (wire.ServiceFlag).
HasFiltering bool
}
// Params defines a Decred network by its parameters. These parameters may be
// used by Decred applications to differentiate networks as well as addresses
// and keys for one network from those intended for use on another network.
type Params struct {
// Name defines a human-readable identifier for the network.
Name string
// Net defines the magic bytes used to identify the network.
Net wire.CurrencyNet
// DefaultPort defines the default peer-to-peer port for the network.
DefaultPort string
// DNSSeeds defines a list of DNS seeds for the network that are used
// as one method to discover peers.
DNSSeeds []DNSSeed
// GenesisBlock defines the first block of the chain.
GenesisBlock *wire.MsgBlock
// GenesisHash is the starting block hash.
GenesisHash *chainhash.Hash
// PowLimit defines the highest allowed proof of work value for a block
// as a uint256.
PowLimit *big.Int
// PowLimitBits defines the highest allowed proof of work value for a
// block in compact form.
PowLimitBits uint32
// ReduceMinDifficulty defines whether the network should reduce the
// minimum required difficulty after a long enough period of time has
// passed without finding a block. This is really only useful for test
// networks and should not be set on a main network.
ReduceMinDifficulty bool
// MinDiffReductionTime is the amount of time after which the minimum
// required difficulty should be reduced when a block hasn't been found.
//
// NOTE: This only applies if ReduceMinDifficulty is true.
MinDiffReductionTime time.Duration
// GenerateSupported specifies whether or not CPU mining is allowed.
GenerateSupported bool
// MaximumBlockSizes are the maximum sizes of a block that can be
// generated on the network. It is an array because the max block size
// can be different values depending on the results of a voting agenda.
// The first entry is the initial block size for the network, while the
// other entries are potential block size changes which take effect when
// the vote for the associated agenda succeeds.
MaximumBlockSizes []int
// MaxTxSize is the maximum number of bytes a serialized transaction can
// be in order to be considered valid by consensus.
MaxTxSize int
// TargetTimePerBlock is the desired amount of time to generate each
// block.
TargetTimePerBlock time.Duration
// WorkDiffAlpha is the stake difficulty EMA calculation alpha (smoothing)
// value. It is different from a normal EMA alpha. Closer to 1 --> smoother.
WorkDiffAlpha int64
// WorkDiffWindowSize is the number of windows (intervals) used for calculation
// of the exponentially weighted average.
WorkDiffWindowSize int64
// WorkDiffWindows is the number of windows (intervals) used for calculation
// of the exponentially weighted average.
WorkDiffWindows int64
// TargetTimespan is the desired amount of time that should elapse
// before the block difficulty requirement is examined to determine how
// it should be changed in order to maintain the desired block
// generation rate. This value should correspond to the product of
// WorkDiffWindowSize and TimePerBlock above.
TargetTimespan time.Duration
// RetargetAdjustmentFactor is the adjustment factor used to limit
// the minimum and maximum amount of adjustment that can occur between
// difficulty retargets.
RetargetAdjustmentFactor int64
// Subsidy parameters.
//
// Subsidy calculation for exponential reductions:
// 0 for i in range (0, height / SubsidyReductionInterval):
// 1 subsidy *= MulSubsidy
// 2 subsidy /= DivSubsidy
//
// Caveat: Don't overflow the int64 register!!
// BaseSubsidy is the starting subsidy amount for mined blocks.
BaseSubsidy int64
// Subsidy reduction multiplier.
MulSubsidy int64
// Subsidy reduction divisor.
DivSubsidy int64
// SubsidyReductionInterval is the reduction interval in blocks.
SubsidyReductionInterval int64
// WorkRewardProportion is the comparative amount of the subsidy given for
// creating a block.
WorkRewardProportion uint16
// StakeRewardProportion is the comparative amount of the subsidy given for
// casting stake votes (collectively, per block).
StakeRewardProportion uint16
// BlockTaxProportion is the inverse of the percentage of funds for each
// block to allocate to the developer organization.
// e.g. 10% --> 10 (or 1 / (1/10))
// Special case: disable taxes with a value of 0
BlockTaxProportion uint16
// Checkpoints ordered from oldest to newest.
Checkpoints []Checkpoint
// These fields are related to voting on consensus rule changes as
// defined by BIP0009.
//
// RuleChangeActivationQurom is the number of votes required for a vote
// to take effect.
//
// RuleChangeActivationInterval is the number of blocks in each threshold
// state retarget window.
//
// Deployments define the specific consensus rule changes to be voted
// on for the stake version (the map key).
RuleChangeActivationQuorum uint32
RuleChangeActivationMultiplier uint32
RuleChangeActivationDivisor uint32
RuleChangeActivationInterval uint32
Deployments map[uint32][]ConsensusDeployment
// Enforce current block version once network has upgraded.
BlockEnforceNumRequired uint64
// Reject previous block versions once network has upgraded.
BlockRejectNumRequired uint64
// The number of nodes to check.
BlockUpgradeNumToCheck uint64
// AcceptNonStdTxs is a mempool param to either accept and relay
// non standard txs to the network or reject them
AcceptNonStdTxs bool
// NetworkAddressPrefix is the first letter of the network
// for any given address encoded as a string.
NetworkAddressPrefix string
// Address encoding magics
PubKeyAddrID [2]byte // First 2 bytes of a P2PK address
PubKeyHashAddrID [2]byte // First 2 bytes of a P2PKH address
PKHEdwardsAddrID [2]byte // First 2 bytes of an Edwards P2PKH address
PKHSchnorrAddrID [2]byte // First 2 bytes of a secp256k1 Schnorr P2PKH address
ScriptHashAddrID [2]byte // First 2 bytes of a P2SH address
PrivateKeyID [2]byte // First 2 bytes of a WIF private key
// BIP32 hierarchical deterministic extended key magics
HDPrivateKeyID [4]byte
HDPublicKeyID [4]byte
// SLIP-0044 registered coin type used for BIP44, used in the hierarchical
// deterministic path for address generation.
// All SLIP-0044 registered coin types are are defined here:
// https://github.com/satoshilabs/slips/blob/master/slip-0044.md
SLIP0044CoinType uint32
// Legacy BIP44 coin type used in the hierarchical deterministic path for
// address generation. Previous name was HDCoinType, the LegacyCoinType
// was introduced for backwards compatibility. Usually, SLIP0044CoinType
// should be used instead.
LegacyCoinType uint32
// MinimumStakeDiff if the minimum amount of Atoms required to purchase a
// stake ticket.
MinimumStakeDiff int64
// Ticket pool sizes for Decred PoS. This denotes the number of possible
// buckets/number of different ticket numbers. It is also the number of
// possible winner numbers there are.
TicketPoolSize uint16
// Average number of tickets per block for Decred PoS.
TicketsPerBlock uint16
// Number of blocks for tickets to mature (spendable at TicketMaturity+1).
TicketMaturity uint16
// Number of blocks for tickets to expire after they have matured. This MUST
// be >= (StakeEnabledHeight + StakeValidationHeight).
TicketExpiry uint32
// CoinbaseMaturity is the number of blocks required before newly mined
// coins (coinbase transactions) can be spent.
CoinbaseMaturity uint16
// Maturity for spending SStx change outputs.
SStxChangeMaturity uint16
// TicketPoolSizeWeight is the multiplicative weight applied to the
// ticket pool size difference between a window period and its target
// when determining the stake system.
TicketPoolSizeWeight uint16
// StakeDiffAlpha is the stake difficulty EMA calculation alpha (smoothing)
// value. It is different from a normal EMA alpha. Closer to 1 --> smoother.
StakeDiffAlpha int64
// StakeDiffWindowSize is the number of blocks used for each interval in
// exponentially weighted average.
StakeDiffWindowSize int64
// StakeDiffWindows is the number of windows (intervals) used for calculation
// of the exponentially weighted average.
StakeDiffWindows int64
// StakeVersionInterval determines the interval where the stake version
// is calculated.
StakeVersionInterval int64
// MaxFreshStakePerBlock is the maximum number of new tickets that may be
// submitted per block.
MaxFreshStakePerBlock uint8
// StakeEnabledHeight is the height in which the first ticket could possibly
// mature.
StakeEnabledHeight int64
// StakeValidationHeight is the height at which votes (SSGen) are required
// to add a new block to the top of the blockchain. This height is the
// first block that will be voted on, but will include in itself no votes.
StakeValidationHeight int64
// StakeBaseSigScript is the consensus stakebase signature script for all
// votes on the network. This isn't signed in any way, so without forcing
// it to be this value miners/daemons could freely change it.
StakeBaseSigScript []byte
// StakeMajorityMultiplier and StakeMajorityDivisor are used
// to calculate the super majority of stake votes using integer math as
// such: X*StakeMajorityMultiplier/StakeMajorityDivisor
StakeMajorityMultiplier int32
StakeMajorityDivisor int32
// OrganizationPkScript is the output script for block taxes to be
// distributed to in every block's coinbase. It should ideally be a P2SH
// multisignature address. OrganizationPkScriptVersion is the version
// of the output script. Until PoS hardforking is implemented, this
// version must always match for a block to validate.
OrganizationPkScript []byte
OrganizationPkScriptVersion uint16
// BlockOneLedger specifies the list of payouts in the coinbase of
// block height 1. If there are no payouts to be given, set this
// to an empty slice.
BlockOneLedger []*TokenPayout
}
var (
// ErrDuplicateNet describes an error where the parameters for a Decred
// network could not be set due to the network already being a standard
// network or previously-registered into this package.
ErrDuplicateNet = errors.New("duplicate Decred network")
// ErrUnknownHDKeyID describes an error where the provided id which
// is intended to identify the network for a hierarchical deterministic
// private extended key is not registered.
ErrUnknownHDKeyID = errors.New("unknown hd private extended key bytes")
)
var (
registeredNets = make(map[wire.CurrencyNet]struct{})
pubKeyAddrIDs = make(map[[2]byte]struct{})
pubKeyHashAddrIDs = make(map[[2]byte]struct{})
pkhEdwardsAddrIDs = make(map[[2]byte]struct{})
pkhSchnorrAddrIDs = make(map[[2]byte]struct{})
scriptHashAddrIDs = make(map[[2]byte]struct{})
hdPrivToPubKeyIDs = make(map[[4]byte][]byte)
)
// String returns the hostname of the DNS seed in human-readable form.
func (d DNSSeed) String() string {
return d.Host
}
// Register registers the network parameters for a Decred network. This may
// error with ErrDuplicateNet if the network is already registered (either
// due to a previous Register call, or the network being one of the default
// networks).
//
// Network parameters should be registered into this package by a main package
// as early as possible. Then, library packages may lookup networks or network
// parameters based on inputs and work regardless of the network being standard
// or not.
func Register(params *Params) error {
if _, ok := registeredNets[params.Net]; ok {
return ErrDuplicateNet
}
registeredNets[params.Net] = struct{}{}
pubKeyAddrIDs[params.PubKeyAddrID] = struct{}{}
pubKeyHashAddrIDs[params.PubKeyHashAddrID] = struct{}{}
scriptHashAddrIDs[params.ScriptHashAddrID] = struct{}{}
hdPrivToPubKeyIDs[params.HDPrivateKeyID] = params.HDPublicKeyID[:]
return nil
}
// mustRegister performs the same function as Register except it panics if there
// is an error. This should only be called from package init functions.
func mustRegister(params *Params) {
if err := Register(params); err != nil {
panic("failed to register network: " + err.Error())
}
}
// IsPubKeyAddrID returns whether the id is an identifier known to prefix a
// pay-to-pubkey address on any default or registered network.
func IsPubKeyAddrID(id [2]byte) bool {
_, ok := pubKeyHashAddrIDs[id]
return ok
}
// IsPubKeyHashAddrID returns whether the id is an identifier known to prefix a
// pay-to-pubkey-hash address on any default or registered network. This is
// used when decoding an address string into a specific address type. It is up
// to the caller to check both this and IsScriptHashAddrID and decide whether an
// address is a pubkey hash address, script hash address, neither, or
// undeterminable (if both return true).
func IsPubKeyHashAddrID(id [2]byte) bool {
_, ok := pubKeyHashAddrIDs[id]
return ok
}
// IsPKHEdwardsAddrID returns whether the id is an identifier know to prefix a
// pay-to-pubkey-hash Edwards address.
func IsPKHEdwardsAddrID(id [2]byte) bool {
_, ok := pkhEdwardsAddrIDs[id]
return ok
}
// IsPKHSchnorrAddrID returns whether the id is an identifier know to prefix a
// pay-to-pubkey-hash secp256k1 Schnorr address.
func IsPKHSchnorrAddrID(id [2]byte) bool {
_, ok := pkhSchnorrAddrIDs[id]
return ok
}
// IsScriptHashAddrID returns whether the id is an identifier known to prefix a
// pay-to-script-hash address on any default or registered network. This is
// used when decoding an address string into a specific address type. It is up
// to the caller to check both this and IsPubKeyHashAddrID and decide whether an
// address is a pubkey hash address, script hash address, neither, or
// undeterminable (if both return true).
func IsScriptHashAddrID(id [2]byte) bool {
_, ok := scriptHashAddrIDs[id]
return ok
}
// HDPrivateKeyToPublicKeyID accepts a private hierarchical deterministic
// extended key id and returns the associated public key id. When the provided
// id is not registered, the ErrUnknownHDKeyID error will be returned.
func HDPrivateKeyToPublicKeyID(id []byte) ([]byte, error) {
if len(id) != 4 {
return nil, ErrUnknownHDKeyID
}
var key [4]byte
copy(key[:], id)
pubBytes, ok := hdPrivToPubKeyIDs[key]
if !ok {
return nil, ErrUnknownHDKeyID
}
return pubBytes, nil
}
// newHashFromStr converts the passed big-endian hex string into a
// chainhash.Hash. It only differs from the one available in chainhash in that
// it panics on an error since it will only (and must only) be called with
// hard-coded, and therefore known good, hashes.
func newHashFromStr(hexStr string) *chainhash.Hash {
hash, err := chainhash.NewHashFromStr(hexStr)
if err != nil {
// Ordinarily I don't like panics in library code since it
// can take applications down without them having a chance to
// recover which is extremely annoying, however an exception is
// being made in this case because the only way this can panic
// is if there is an error in the hard-coded hashes. Thus it
// will only ever potentially panic on init and therefore is
// 100% predictable.
panic(err)
}
return hash
}
func hexDecode(hexStr string) []byte {
b, err := hex.DecodeString(hexStr)
if err != nil {
panic(err)
}
return b
}
// BlockOneSubsidy returns the total subsidy of block height 1 for the
// network.
func (p *Params) BlockOneSubsidy() int64 {
if len(p.BlockOneLedger) == 0 {
return 0
}
sum := int64(0)
for _, output := range p.BlockOneLedger {
sum += output.Amount
}
return sum
}
// TotalSubsidyProportions is the sum of WorkReward, StakeReward, and BlockTax
// proportions.
func (p *Params) TotalSubsidyProportions() uint16 {
return p.WorkRewardProportion + p.StakeRewardProportion + p.BlockTaxProportion
}
// LatestCheckpointHeight is the height of the latest checkpoint block in the
// parameters.
func (p *Params) LatestCheckpointHeight() int64 {
if len(p.Checkpoints) == 0 {
return 0
}
return p.Checkpoints[len(p.Checkpoints)-1].Height
}
func init() {
// Register all default networks when the package is initialized.
mustRegister(&MainNetParams)
mustRegister(&TestNet3Params)
mustRegister(&SimNetParams)
}