虚拟币开发专题（自己动手制作山寨币教程）

源代码地址：
https://github.com/imharrywu/fastcoin

程序猿朋友可以自己动手编译生成安装包，有问题可以直接加群讨论 306888500(注明：csdn)，也欢迎程序猿朋友PullRequest给我，只有知识共享才能促进比特币的繁荣。

可以支持任何算法（sha256，scrypt，x11，x13，nist，grostel，以及这些算法的串联）和参数定制。

目前预先内置了比特币的SHA256和莱特币的scypt，以及SHA3-256(KECCAK)。

在线编译目前提供三种安装包：
1，Linux/unix的daemon程序（带钱包功能）
2，Mac钱包安装包
3，windows钱包安装包

如果看完此文您觉得有用，欢迎捐赠博主：
1MMkfgNEw96B83DQq3DFtL9WxcTN7keFPG

1、截图预览
(1) 安装图1

（2）安装图2

（3）安装图3

（4）安装图4

（5）安装图5

（6）概览图已经挖到3个block 奖励了300个FTC

（7）交易记录图

（8）点击显示交易细节显示为挖矿所得并且还没有确认

（9）版权页

（10）调试窗口

（11）显示已经连接的p2p网络节点一个在虚拟机里面运行的节点

（12）2个节点构成的p2p通信网络

2、山寨币修改步骤：
（1）迁出最新的比特币源代码
比特币官方代码: https://github.com/bitcoin/bitcoin
山寨币代码地址（紧跟bitcoin更新）:https://github.com/imharrywu/fastcoin
Git clone https://github.com/imharrywu/fastcoin

一下修改都是一些代码片段，请用eclipse打开迁出的代码，对照查看。

（2）修改创世块
源文件 chainparams.cpp
[cpp] view plain copy
/**
* Build the genesis block. Note that the output of the genesis coinbase cannot
* be spent as it did not originally exist in the database.
*
* CBlock(hash=000000000019d6, ver=1, hashPrevBlock=00000000000000, hashMerkleRoot=4a5e1e, nTime=1231006505, nBits=1d00ffff, nNonce=2083236893, vtx=1)
* CTransaction(hash=4a5e1e, ver=1, vin.size=1, vout.size=1, nLockTime=0)
* CTxIn(COutPoint(000000, -1), coinbase 04ffff001d0104455468652054696d65732030332f4a616e2f32303039204368616e63656c6c6f72206f6e206272696e6b206f66207365636f6e64206261696c6f757420666f722062616e6b73)
* CTxOut(nValue=50.00000000, scriptPubKey=0x5F1DF16B2B704C8A578D0B)
* vMerkleTree: 4a5e1e
*/

// HarryWu, generate genesis block by genesis.py as following:
//
// localhost genesis # python genesis.py \
// -t $(date +%s) \
// -z "shanghai stock index closed at 2343.57, on 24th Sept., 2014" \
// -a SHA256 \
// -p 049e02fa9aa3c19a3b112a58bab503c5caf797972f5cfe1006275aa5485a01b48f9f648bc5380ee1e82dc6f474c8e0f7e2f6bbd0de9355f92496e3ea327ccb19cc \
// -v 10000000000
// Raw block data: 04ffff001d01043b7368616e676861692073746f636b20696e64657820636c6f73656420617420323334332e35372c206f6e203234746820536570742e2c2032303134
// algorithm: SHA256
// merkle hash: 1c395aad7fab156523a095a869d3fcdf3249a8a97c8d7337adb4f33d826da32b
// pszTimestamp: shanghai stock index closed at 2343.57, on 24th Sept., 2014
// pubkey: 049e02fa9aa3c19a3b112a58bab503c5caf797972f5cfe1006275aa5485a01b48f9f648bc5380ee1e82dc6f474c8e0f7e2f6bbd0de9355f92496e3ea327ccb19cc
// time: 1411650667
// bits: 0x1d00ffff
// Searching for genesis hash..
//
// nonce: 1456993276
// genesis hash: 000000004df0288b461e17d9a20e557fd296861c604f1944eb9e2cca866af0a5

const char* pszTimestamp = "shanghai stock index closed at 2343.57, on 24th Sept., 2014";
CMutableTransaction txNew;
txNew.vin.resize(1);
txNew.vout.resize(1);
txNew.vin[0].scriptSig = CScript() << 0x1d00ffff << CScriptNum(4) << vector<unsigned char>((const unsigned char*)pszTimestamp, (const unsigned char*)pszTimestamp + strlen(pszTimestamp));
txNew.vout[0].nValue = nGenesisSubsidy * COIN;
txNew.vout[0].scriptPubKey = CScript() << ParseHex("049e02fa9aa3c19a3b112a58bab503c5caf797972f5cfe1006275aa5485a01b48f9f648bc5380ee1e82dc6f474c8e0f7e2f6bbd0de9355f92496e3ea327ccb19cc") << OP_CHECKSIG;
genesis.vtx.push_back(txNew);
genesis.hashPrevBlock = 0;
genesis.hashMerkleRoot = genesis.BuildMerkleTree();
genesis.nVersion = 1;
genesis.nTime = 1411666331;
genesis.nBits = 0x1d00ffff;
genesis.nNonce = 2056985438;

hashGenesisBlock = genesis.GetHash();
assert(hashGenesisBlock == uint256("0x0000000061b1aca334b059920fed7bace2336ea4d23d63428c7aee04da49e942"));
assert(genesis.hashMerkleRoot == uint256("0x7bf229f629a6666596c1ce57117c28d1d29299e8a5303347929bd70847c49adb"));

（3）修改网络协议魔数
源文件 chainparams.cpp
[cpp] view plain copy
class CMainParams : public CChainParams {
public:
CMainParams() {
networkID = CBaseChainParams::MAIN;
strNetworkID = "main";
/**
* The message start string is designed to be unlikely to occur in normal data.
* The characters are rarely used upper ASCII, not valid as UTF-8, and produce
* a large 4-byte int at any alignment.
*/
pchMessageStart[0] = 0x90;
pchMessageStart[1] = 0x0d;
pchMessageStart[2] = 0xf0;
pchMessageStart[3] = 0x0d;

0xgoodcafe(好咖啡的意思），大家可以自己选择，但是也有一些基本建议，看上面那个英文注释就好了，就是和某些常用的字符集可用字段不要冲突。
另外：对应的修改TESTNET和REGTESTNET的参数

（4）修改地址前缀
源文件 chainparams.cpp
[cpp] view plain copy
base58Prefixes[PUBKEY_ADDRESS] = list_of(35); // F prefix
base58Prefixes[SCRIPT_ADDRESS] = list_of(65); // T prefix
base58Prefixes[SECRET_KEY] = list_of(45); // 7 prefix
base58Prefixes[EXT_PUBLIC_KEY] = list_of(0x04)(0x88)(0xEE)(0x35);
base58Prefixes[EXT_SECRET_KEY] = list_of(0x04)(0x88)(0xEE)(0x45);

有一个wiki的对照表可以用来悬在公钥和脚本地址的前缀，但是这个表不使用私钥等（因为长度不一样，规律不一样）。

（5）修改网络端口
源文件 chainparams.cpp
[cpp] view plain copy
class CMainParams : public CChainParams {
public:
CMainParams() {
networkID = CBaseChainParams::MAIN;
strNetworkID = "main";
/**
* The message start string is designed to be unlikely to occur in normal data.
* The characters are rarely used upper ASCII, not valid as UTF-8, and produce
* a large 4-byte int at any alignment.
*/
pchMessageStart[0] = 0x90;
pchMessageStart[1] = 0x0d;
pchMessageStart[2] = 0xf0;
pchMessageStart[3] = 0x0d;
vAlertPubKey = ParseHex("04e01590abdc5967eb550413fcf04bbd7cead46f13579b58d52ea2f08d71a1a94196c476cd4fa60c30b51737fe3d9c8c88a04a6bec2282ebb1f22286130a153b85");
nDefaultPort = 9999;
bnProofOfWorkLimit = ~uint256(0) >> 32;

修改了nDefaultPort=9999，比特币默认是8333
另外同时修改一下TESTNET和REGTESTNET的端口配置，一般加10000和20000即可
[cpp] view plain copy
/**
* Testnet (v3)
*/
class CTestNetParams : public CMainParams {
public:
CTestNetParams() {
networkID = CBaseChainParams::TESTNET;
strNetworkID = "test";
pchMessageStart[0] = 0xC0;
pchMessageStart[1] = 0x1d;
pchMessageStart[2] = 0xf0;
pchMessageStart[3] = 0x0d;
vAlertPubKey = ParseHex("045d2d29beffb0a0cbea44f266286ff8b1d11c035538fbb4dadcf6b4073b08f318afea74f01d5a3782e72a22273fb01ab40e99d93adff488236585cc8031323e7c");
nDefaultPort = 19999;

[cpp] view plain copy
/**
* Regression test
*/
class CRegTestParams : public CTestNetParams {
public:
CRegTestParams() {
networkID = CBaseChainParams::REGTEST;
strNetworkID = "regtest";
pchMessageStart[0] = 0x0b;
pchMessageStart[1] = 0xad;
pchMessageStart[2] = 0xf0;
pchMessageStart[3] = 0x0d;
nDefaultPort = 29999;
bnProofOfWorkLimit = ~uint256(0) >> 1;

（6）修改种子网络连接参数
源文件 chainparams.cpp
[cpp] view plain copy
//vSeeds.push_back(CDNSSeedData("bitcoin.sipa.be", "seed.bitcoin.sipa.be"));
//vSeeds.push_back(CDNSSeedData("bluematt.me", "dnsseed.bluematt.me"));
//vSeeds.push_back(CDNSSeedData("dashjr.org", "dnsseed.bitcoin.dashjr.org"));
//vSeeds.push_back(CDNSSeedData("bitcoinstats.com", "seed.bitcoinstats.com"));
//vSeeds.push_back(CDNSSeedData("bitnodes.io", "seed.bitnodes.io"));
//vSeeds.push_back(CDNSSeedData("xf2.org", "bitseed.xf2.org"));

base58Prefixes[PUBKEY_ADDRESS] = list_of(35); // F prefix
base58Prefixes[SCRIPT_ADDRESS] = list_of(65); // T prefix
base58Prefixes[SECRET_KEY] = list_of(45); // 7 prefix
base58Prefixes[EXT_PUBLIC_KEY] = list_of(0x04)(0x88)(0xEE)(0x35);
base58Prefixes[EXT_SECRET_KEY] = list_of(0x04)(0x88)(0xEE)(0x45);

//convertSeed6(vFixedSeeds, pnSeed6_main, ARRAYLEN(pnSeed6_main));

如果你有7x24在线的服务器运行节点，那么请在这里加入他们的地址，可以是dns也可以是ip地址（v4，v6，--enable-ipv6）。
如果没有的话，可以考虑和我一样暂时注释掉，在运行时候指定连接参数-addnoe=123.123.123.123 或者-dns -addnode=mynode.domain.com
对应的修改一下TESTNET和REGTESTNET的网络节点地址。

（7）修改工作量机制
源文件 miner.cpp
比特币在函数ScanHash（）里面搜索随机数，
[cpp] view plain copy
//
// ScanHash scans nonces looking for a hash with at least some zero bits.
// The nonce is usually preserved between calls, but periodically or if the
// nonce is 0xffff0000 or above, the block is rebuilt and nNonce starts over at
// zero.
//
bool static ScanHash(const CBlockHeader *pblock, uint32_t& nNonce, uint256 *phash)
{
// Write the first 76 bytes of the block header to a double-SHA256 state.
//CHash256 hasher;
//CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
//ss << *pblock;
//assert(ss.size() == 80);
//hasher.Write((unsigned char*)&ss[0], 76);

while (true) {
nNonce++;

// Write the last 4 bytes of the block header (the nonce) to a copy of
// the double-SHA256 state, and compute the result.
//CHash256(hasher).Write((unsigned char*)&nNonce, 4).Finalize((unsigned char*)phash);

*phash = pblock->ComputePowHash(nNonce);

// Return the nonce if the hash has at least some zero bits,
// caller will check if it has enough to reach the target
if (((uint16_t*)phash)[15] == 0)
return true;

// If nothing found after trying for a while, return -1
if ((nNonce & 0xffff) == 0)
return false;
if ((nNonce & 0xfff) == 0)
boost::this_thread::interruption_point();
}
}

在函数BitcoinMiner()里面创建新的block，设定时间戳(扰动1)，获取mempool里面的最新交易(扰动2)，调用ScanHash()搜索随机数(扰动3），直到找到满足条件的hash。
另外比特币的工作量证明的hash同时用作这个block的索引，litecoin里面这2个概念是区分的对待的(sha256的hash作为索引，scrypt出来的pow hash作为工作量证明)。
注意：设置独立挖矿的条件(chainparams.cpp里面设置)
[cpp] view plain copy
fMiningRequiresPeers = !true; // See BitcoinMiner() for details.

挖矿代码：
[cpp] view plain copy
void static BitcoinMiner(CWallet *pwallet)
{
LogPrintf("FastCoinMiner started\n");
SetThreadPriority(THREAD_PRIORITY_LOWEST);
RenameThread("fastcoin-miner");

// Each thread has its own key and counter
CReserveKey reservekey(pwallet);
unsigned int nExtraNonce = 0;

try {
while (true) {
if (Params().MiningRequiresPeers()) {
// Busy-wait for the network to come online so we don't waste time mining
// on an obsolete chain. In regtest mode we expect to fly solo.
while (vNodes.empty())
MilliSleep(1000);
}

//
// Create new block
//
unsigned int nTransactionsUpdatedLast = mempool.GetTransactionsUpdated();
CBlockIndex* pindexPrev = chainActive.Tip();

auto_ptr<CBlockTemplate> pblocktemplate(CreateNewBlockWithKey(reservekey));
if (!pblocktemplate.get())
{
LogPrintf("Error in FastCoinMiner: Keypool ran out, please call keypoolrefill before restarting the mining thread\n");
return;
}
CBlock *pblock = &pblocktemplate->block;
IncrementExtraNonce(pblock, pindexPrev, nExtraNonce);

LogPrintf("Running FastCoinMiner with %u transactions in block (%u bytes)\n", pblock->vtx.size(),
::GetSerializeSize(*pblock, SER_NETWORK, PROTOCOL_VERSION));

博主稍作修改，设置了几个预置的hash算法（sha256，scrypt，keccak（即SHA3))，可以通过block的版本号区分，那么在scanhash里面调用ComputePowHash的时候，可以选择不同的pow算法，甚至你可以把这些算法串联起来，以增加算法被破解的方攻击性。
看代码吧：
[cpp] view plain copy
uint256 CBlockHeader::ComputePowHash(uint32_t nNonce) const
{
if (nVersion == 1 || nVersion == 2){
/**
* Use SHA256+SHA256 to make PoW
*/
// Write the first 76 bytes of the block header to a double-SHA256 state.
CDoubleSHA256Pow hasher; // TODO: Create a new PowHasher named CPowHash256
CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
ss << *this;
assert(ss.size() == 80);
hasher.Write((unsigned char*)&ss[0], 76);
uint256 powHash;
CDoubleSHA256Pow(hasher).Write((unsigned char*)&nNonce, 4).Finalize((unsigned char*)&powHash);
return powHash;
}else if (nVersion == 3){
/**
* Scrypt PoW
*/
CScryptHash256Pow hasher;
CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
ss << *this;
assert(ss.size() == 80);
hasher.Write((unsigned char*)&ss[0], 76);
uint256 powHash;
CScryptHash256Pow(hasher).Write((unsigned char*)&nNonce, 4).Finalize((unsigned char*)&powHash);
return powHash;
}else if (nVersion == 4){
/**
* Scrypt+SHA256 PoW
*/
}else if (nVersion == 5){
/**
* Keccak(1088,512,256) or Known as SHA3-256(fips202draft) Pow
*/
CKeccak_256 hasher;
CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
ss << *this;
assert(ss.size() == 80);
hasher.Write((unsigned char*)&ss[0], 76);
uint256 powHash;
CKeccak_256(hasher).Write((unsigned char*)&nNonce, 4).Finalize((unsigned char*)&powHash);
return powHash;
}else{
// Abort, unknown block version.
assert(false);
return ~(uint256)0;
}
}

（8）修改奖励机制
参考9.3
8.1) 修改挖矿奖励的成熟时间
源代码：main.h
[cpp] view plain copy
/** Coinbase transaction outputs can only be spent after this number of new blocks (network rule) */
static const int COINBASE_MATURITY = 14;

8.2) 修改交易确认块数推荐值
源代码 qt/transactionrecord.h
[cpp] view plain copy
/** UI model for a transaction. A core transaction can be represented by multiple UI transactions if it has
multiple outputs.
*/
class TransactionRecord
{
public:
enum Type
{
Other,
Generated,
SendToAddress,
SendToOther,
RecvWithAddress,
RecvFromOther,
SendToSelf
};

/** Number of confirmation recommended for accepting a transaction */
static const int RecommendedNumConfirmations = 2;

（9）修改难度配置
源文件 chainparams.cpp
[cpp] view plain copy
class CMainParams : public CChainParams {
public:
CMainParams() {
networkID = CBaseChainParams::MAIN;
strNetworkID = "main";
/**
* The message start string is designed to be unlikely to occur in normal data.
* The characters are rarely used upper ASCII, not valid as UTF-8, and produce
* a large 4-byte int at any alignment.
*/
pchMessageStart[0] = 0x90;
pchMessageStart[1] = 0x0d;
pchMessageStart[2] = 0xf0;
pchMessageStart[3] = 0x0d;
vAlertPubKey = ParseHex("04e01590abdc5967eb550413fcf04bbd7cead46f13579b58d52ea2f08d71a1a94196c476cd4fa60c30b51737fe3d9c8c88a04a6bec2282ebb1f22286130a153b85");
nDefaultPort = 9999;
bnProofOfWorkLimit = ~uint256(0) >> 32;
nSubsidyHalvingInterval = 210000;
nEnforceBlockUpgradeMajority = 750;
nRejectBlockOutdatedMajority = 950;
nToCheckBlockUpgradeMajority = 1000;
nMinerThreads = 1; // 0 for all available cpus.
nTargetTimespan = 60 * 60; // re-targeting every one hour
nTargetSpacing = 1 * 60; // do new pow every 1 minutes.
nGenesisSubsidy = 100;

a) bnProofOfWorkLimit=~uint256(0) >> 32;
是一个大整数（256bit）表示，前面32个位数是0，这个参数表示全网允许的最小难度，低于这个难度的block是不会被挖掘的。

b) nGenesisSubsidy = 100;
初始津贴，比特币的第一个块的奖励是50个btc。

c) nSubsidyHavlingInterval = 210000;
这个参数决定了多少个block以后比特币的奖励（补贴，挖矿奖励)会减半。这个参数结合初始奖励（比如比特币50）基本可以估算全网总的货币产量（比如比特币的2100万），这个初始津贴也是可以配置的，如2）所示。比如比特币，一个等比数列求和公式就可以计算货币总量 50(1/(1 - 0.5))*210000=2100万btc。
上面2个参数在查询区块奖励的时候用到，请查看main.cpp 的 GetBlockValue(height, fees)找到细节
[cpp] view plain copy
CAmount GetBlockValue(int nHeight, const CAmount& nFees)
{
CAmount nSubsidy = Params().GenesisSubsidy() * COIN;

int halvings = nHeight / Params().SubsidyHalvingInterval();

// Force block reward to zero when right shift is undefined.
if (halvings >= 64)
return nFees;

// Subsidy is cut in half every 210,000 blocks which will occur approximately every 4 years.
nSubsidy >>= halvings;

return nSubsidy + nFees;
}
很多山寨比也是在这里修改货币分布的，比如 nHeight==1 的时候，奖励1000万个，其他块都不予奖励，这个即使预挖模式了吧。
另外，关于货币分布，这里satoshi同学可能已经考虑很多，他为什么设置到很多年以后才矿源枯竭，为什么采取递减的方式，可能都是出于保护区块链的目的（timestampserver）。
d）难度调节周期
nTargetTimespan = 60 * 60; // re-targeting every one hour
nTargetSpacing = 1 * 60; // do new pow every 1 minutes.
这里的设置是60分钟（3600秒），重新评估难度，下一个块的挖掘可能就要使用新的难度设置了。
区块挖掘超时设置，在网络算力足够的情况下，一个节点可以挖矿的时间是有限的，比如这里这是的1分钟（60秒），超过这个时间，要么提交目前已找到的block（nNonce），要放弃自己的挖掘结果（使用网络上其他节点找到的一个最优结果）来寻找下一个block。否则其他节点也已经开始寻找next了，不过这个前提是算力足够，比如btc网络（现在应该到78个0的位置了吧），你如果10分钟内找不到，那么好了，可以放弃了，用别人的block吧，赶紧进入下一个回合的挖掘，否则很可能是浪费时间。
比特币的调节周期是 2周/每10分钟，也就是 2 * 7 * 24 * 6 = 2016
参考：http://bitcoindifficulty.com/blog/
https://en.bitcoin.it/wiki/Difficulty

(10) 修改checkpoints检查

(11) 修改界面

github地址

TODO:
1）模板化的山寨币生成，可配置修改部分通过宏或者变量提取出来，用脚本批量替换修改。
2）矿池搭建与节点测试 P2pool &Poclbm
3）移动支付和网页支付
4）应用生态
5）交易备注
6）复杂交易应用(脚本，非标准交易）

备注：
1）记得加上-checkpoints=0 参数启动，否则，会导致daemon报错，“FastCoin is downloading blocks...”

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