解析genesis.py
创世区块参数生成脚本genesis.py:
1.获取命令行输入的参数
options = get_args()
-t 时间 默认为当前系统时间
-z 一个字符串 默认为The Times 03/Jan/2009 Chancellor on brink of second bailout for banks
-n nonce值 默认为0
-a hash加密算法 默认为SHA256
-p 有效的随机公钥 默认为"04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5f"
-v 版本号 默认为5000000000
def get_args():
parser = optparse.OptionParser()
parser.add_option("-t", "--time", dest="time", default=int(time.time()),
type="int", help="the (unix) time when the genesisblock is created")
parser.add_option("-z", "--timestamp", dest="timestamp", default="The Times 03/Jan/2009 Chancellor on brink of second bailout for banks",
type="string", help="the pszTimestamp found in the coinbase of the genesisblock")
parser.add_option("-n", "--nonce", dest="nonce", default=0,
type="int", help="the first value of the nonce that will be incremented when searching the genesis hash")
parser.add_option("-a", "--algorithm", dest="algorithm", default="SHA256",
help="the PoW algorithm: [SHA256|scrypt|X11|X13|X15]")
parser.add_option("-p", "--pubkey", dest="pubkey", default="04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5f",
type="string", help="the pubkey found in the output script")
parser.add_option("-v", "--value", dest="value", default=5000000000,
type="int", help="the value in coins for the output, full value (exp. in bitcoin 5000000000 - To get other coins value: Block Value * 100000000)")
(options, args) = parser.parse_args()
return options
2.通过命令行的-a 获取对应的加密算法，默认为SHA256
algorithm = get_algorithm(options)
def get_algorithm(options):
supported_algorithms = ["SHA256", "scrypt", "X11", "X13", "X15"]
if options.algorithm in supported_algorithms:
return options.algorithm
else:
sys.exit("Error: Given algorithm must be one of: " + str(supported_algorithms))
3.通过2步骤中获取到的算法算出对应的nbits和target值
bits, target = get_difficulty(algorithm)
def get_difficulty(algorithm):
if algorithm == "scrypt":
return 0x1e0ffff0, 0x0ffff0 * 2**(8*(0x1e - 3))
elif algorithm == "SHA256":
return 0x1d00ffff, 0x00ffff * 2**(8*(0x1d - 3))
elif algorithm == "X11" or algorithm == "X13" or algorithm == "X15":
return 0x1e0ffff0, 0x0ffff0 * 2**(8*(0x1e - 3))
4.创建输入输出脚本：
通过时间戳创建输入脚本，通过公钥创建输出脚本。
input_script = create_input_script(options.timestamp)
output_script = create_output_script(options.pubkey)
输入脚本创建：
def create_input_script(psz_timestamp):
psz_prefix = ""
#use OP_PUSHDATA1 if required
if len(psz_timestamp) > 76: psz_prefix = '4c' #若psz_timestamp长度大于76，则加上前缀4c(76的十六进制)
script_prefix = '04ffff001d0104' + psz_prefix + chr(len(psz_timestamp)).encode('hex') #将它们链接起来成一个脚本前缀
print (script_prefix + psz_timestamp.encode('hex')) #打印04ffff001d010436323031382f332f32302057726974656e206279205374616e77617920456d61696c3a7374616e77617939323040676d61696c2e636f6d
return (script_prefix + psz_timestamp.encode('hex')).decode('hex') #函数返回整个脚本
输出脚本创建：
def create_output_script(pubkey):
script_len = '41'
OP_CHECKSIG = 'ac'
return (script_len + pubkey + OP_CHECKSIG).decode('hex')
#通过公钥创建输出脚本
5.通过输入输出脚本以及各参数创建交易
def create_transaction(input_script, output_script,options):
transaction = Struct("transaction",
Bytes("version", 4),
Byte("num_inputs"),
StaticField("prev_output", 32),
UBInt32('prev_out_idx'),
Byte('input_script_len'),
Bytes('input_script', len(input_script)),
UBInt32('sequence'),
Byte('num_outputs'),
Bytes('out_value', 8),
Byte('output_script_len'),
Bytes('output_script', 0x43),
UBInt32('locktime'))
tx = transaction.parse('\x00'*(127 + len(input_script)))
tx.version = struct.pack('