294 lines
11 KiB
Python
294 lines
11 KiB
Python
import binascii
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from random import choice
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from . import sm3, func
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from Cryptodome.Util.asn1 import DerSequence, DerInteger
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from binascii import unhexlify
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# 选择素域，设置椭圆曲线参数
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default_ecc_table = {
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'n': 'FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFF7203DF6B21C6052B53BBF40939D54123',
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'p': 'FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFF',
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'g': '32c4ae2c1f1981195f9904466a39c9948fe30bbff2660be1715a4589334c74c7'
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'bc3736a2f4f6779c59bdcee36b692153d0a9877cc62a474002df32e52139f0a0',
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'a': 'FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFC',
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'b': '28E9FA9E9D9F5E344D5A9E4BCF6509A7F39789F515AB8F92DDBCBD414D940E93',
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}
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class CryptSM2(object):
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def __init__(self, private_key, public_key, ecc_table=default_ecc_table, mode=0, asn1=False):
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"""
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mode: 0-C1C2C3, 1-C1C3C2 (default is 1)
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"""
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self.private_key = private_key
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self.public_key = public_key.lstrip("04") if public_key.startswith("04") else public_key
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self.para_len = len(ecc_table['n'])
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self.ecc_a3 = (
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int(ecc_table['a'], base=16) + 3) % int(ecc_table['p'], base=16)
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self.ecc_table = ecc_table
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assert mode in (0, 1), 'mode must be one of (0, 1)'
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self.mode = mode
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self.asn1 = asn1
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def _kg(self, k, Point): # kP运算
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Point = '%s%s' % (Point, '1')
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mask_str = '8'
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for i in range(self.para_len - 1):
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mask_str += '0'
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mask = int(mask_str, 16)
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Temp = Point
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flag = False
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for n in range(self.para_len * 4):
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if (flag):
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Temp = self._double_point(Temp)
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if (k & mask) != 0:
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if (flag):
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Temp = self._add_point(Temp, Point)
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else:
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flag = True
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Temp = Point
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k = k << 1
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return self._convert_jacb_to_nor(Temp)
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def _double_point(self, Point): # 倍点
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l = len(Point)
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len_2 = 2 * self.para_len
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if l < self.para_len * 2:
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return None
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else:
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x1 = int(Point[0:self.para_len], 16)
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y1 = int(Point[self.para_len:len_2], 16)
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if l == len_2:
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z1 = 1
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else:
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z1 = int(Point[len_2:], 16)
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T6 = (z1 * z1) % int(self.ecc_table['p'], base=16)
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T2 = (y1 * y1) % int(self.ecc_table['p'], base=16)
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T3 = (x1 + T6) % int(self.ecc_table['p'], base=16)
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T4 = (x1 - T6) % int(self.ecc_table['p'], base=16)
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T1 = (T3 * T4) % int(self.ecc_table['p'], base=16)
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T3 = (y1 * z1) % int(self.ecc_table['p'], base=16)
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T4 = (T2 * 8) % int(self.ecc_table['p'], base=16)
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T5 = (x1 * T4) % int(self.ecc_table['p'], base=16)
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T1 = (T1 * 3) % int(self.ecc_table['p'], base=16)
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T6 = (T6 * T6) % int(self.ecc_table['p'], base=16)
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T6 = (self.ecc_a3 * T6) % int(self.ecc_table['p'], base=16)
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T1 = (T1 + T6) % int(self.ecc_table['p'], base=16)
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z3 = (T3 + T3) % int(self.ecc_table['p'], base=16)
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T3 = (T1 * T1) % int(self.ecc_table['p'], base=16)
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T2 = (T2 * T4) % int(self.ecc_table['p'], base=16)
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x3 = (T3 - T5) % int(self.ecc_table['p'], base=16)
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if (T5 % 2) == 1:
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T4 = (T5 + ((T5 + int(self.ecc_table['p'], base=16)) >> 1) - T3) % int(
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self.ecc_table['p'], base=16)
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else:
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T4 = (T5 + (T5 >> 1) - T3) % int(self.ecc_table['p'], base=16)
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T1 = (T1 * T4) % int(self.ecc_table['p'], base=16)
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y3 = (T1 - T2) % int(self.ecc_table['p'], base=16)
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form = '%%0%dx' % self.para_len
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form = form * 3
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return form % (x3, y3, z3)
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def _add_point(self, P1, P2): # 点加函数，P2点为仿射坐标即z=1，P1为Jacobian加重射影坐标
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len_2 = 2 * self.para_len
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l1 = len(P1)
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l2 = len(P2)
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if (l1 < len_2) or (l2 < len_2):
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return None
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else:
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X1 = int(P1[0:self.para_len], 16)
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Y1 = int(P1[self.para_len:len_2], 16)
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if (l1 == len_2):
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Z1 = 1
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else:
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Z1 = int(P1[len_2:], 16)
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x2 = int(P2[0:self.para_len], 16)
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y2 = int(P2[self.para_len:len_2], 16)
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T1 = (Z1 * Z1) % int(self.ecc_table['p'], base=16)
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T2 = (y2 * Z1) % int(self.ecc_table['p'], base=16)
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T3 = (x2 * T1) % int(self.ecc_table['p'], base=16)
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T1 = (T1 * T2) % int(self.ecc_table['p'], base=16)
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T2 = (T3 - X1) % int(self.ecc_table['p'], base=16)
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T3 = (T3 + X1) % int(self.ecc_table['p'], base=16)
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T4 = (T2 * T2) % int(self.ecc_table['p'], base=16)
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T1 = (T1 - Y1) % int(self.ecc_table['p'], base=16)
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Z3 = (Z1 * T2) % int(self.ecc_table['p'], base=16)
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T2 = (T2 * T4) % int(self.ecc_table['p'], base=16)
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T3 = (T3 * T4) % int(self.ecc_table['p'], base=16)
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T5 = (T1 * T1) % int(self.ecc_table['p'], base=16)
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T4 = (X1 * T4) % int(self.ecc_table['p'], base=16)
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X3 = (T5 - T3) % int(self.ecc_table['p'], base=16)
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T2 = (Y1 * T2) % int(self.ecc_table['p'], base=16)
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T3 = (T4 - X3) % int(self.ecc_table['p'], base=16)
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T1 = (T1 * T3) % int(self.ecc_table['p'], base=16)
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Y3 = (T1 - T2) % int(self.ecc_table['p'], base=16)
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form = '%%0%dx' % self.para_len
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form = form * 3
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return form % (X3, Y3, Z3)
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def _convert_jacb_to_nor(self, Point): # Jacobian加重射影坐标转换成仿射坐标
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len_2 = 2 * self.para_len
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x = int(Point[0:self.para_len], 16)
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y = int(Point[self.para_len:len_2], 16)
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z = int(Point[len_2:], 16)
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z_inv = pow(
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z, int(self.ecc_table['p'], base=16) - 2, int(self.ecc_table['p'], base=16))
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z_invSquar = (z_inv * z_inv) % int(self.ecc_table['p'], base=16)
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z_invQube = (z_invSquar * z_inv) % int(self.ecc_table['p'], base=16)
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x_new = (x * z_invSquar) % int(self.ecc_table['p'], base=16)
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y_new = (y * z_invQube) % int(self.ecc_table['p'], base=16)
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z_new = (z * z_inv) % int(self.ecc_table['p'], base=16)
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if z_new == 1:
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form = '%%0%dx' % self.para_len
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form = form * 2
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return form % (x_new, y_new)
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else:
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return None
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def verify(self, Sign, data):
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# 验签函数，sign签名r||s，E消息hash，public_key公钥
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if self.asn1:
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unhex_sign = unhexlify(Sign.encode())
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seq_der = DerSequence()
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origin_sign = seq_der.decode(unhex_sign)
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r = origin_sign[0]
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s = origin_sign[1]
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else:
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r = int(Sign[0:self.para_len], 16)
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s = int(Sign[self.para_len:2*self.para_len], 16)
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e = int(data.hex(), 16)
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t = (r + s) % int(self.ecc_table['n'], base=16)
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if t == 0:
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return 0
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P1 = self._kg(s, self.ecc_table['g'])
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P2 = self._kg(t, self.public_key)
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# print(P1)
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# print(P2)
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if P1 == P2:
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P1 = '%s%s' % (P1, 1)
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P1 = self._double_point(P1)
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else:
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P1 = '%s%s' % (P1, 1)
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P1 = self._add_point(P1, P2)
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P1 = self._convert_jacb_to_nor(P1)
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x = int(P1[0:self.para_len], 16)
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return r == ((e + x) % int(self.ecc_table['n'], base=16))
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def sign(self, data, K):
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"""
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签名函数, data消息的hash，private_key私钥，K随机数，均为16进制字符串
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:param self:
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:param data: data消息的hash
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:param K: K随机数
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:return:
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"""
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E = data.hex() # 消息转化为16进制字符串
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e = int(E, 16)
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d = int(self.private_key, 16)
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k = int(K, 16)
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P1 = self._kg(k, self.ecc_table['g'])
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x = int(P1[0:self.para_len], 16)
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R = ((e + x) % int(self.ecc_table['n'], base=16))
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if R == 0 or R + k == int(self.ecc_table['n'], base=16):
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return None
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d_1 = pow(
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d+1, int(self.ecc_table['n'], base=16) - 2, int(self.ecc_table['n'], base=16))
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S = (d_1*(k + R) - R) % int(self.ecc_table['n'], base=16)
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if S == 0:
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return None
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elif self.asn1:
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return DerSequence([DerInteger(R), DerInteger(S)]).encode().hex()
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else:
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return '%064x%064x' % (R, S)
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def encrypt(self, data):
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# 加密函数，data消息(bytes)
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msg = data.hex() # 消息转化为16进制字符串
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k = func.random_hex(self.para_len)
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C1 = self._kg(int(k, 16), self.ecc_table['g'])
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xy = self._kg(int(k, 16), self.public_key)
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x2 = xy[0:self.para_len]
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y2 = xy[self.para_len:2*self.para_len]
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ml = len(msg)
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t = sm3.sm3_kdf(xy.encode('utf8'), ml/2)
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if int(t, 16) == 0:
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return None
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else:
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form = '%%0%dx' % ml
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C2 = form % (int(msg, 16) ^ int(t, 16))
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C3 = sm3.sm3_hash([
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i for i in bytes.fromhex('%s%s%s' % (x2, msg, y2))
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])
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if self.mode:
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return bytes.fromhex('%s%s%s' % (C1, C3, C2))
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else:
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return bytes.fromhex('%s%s%s' % (C1, C2, C3))
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def decrypt(self, data):
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# 解密函数，data密文（bytes）
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data = data.hex()
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len_2 = 2 * self.para_len
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len_3 = len_2 + 64
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C1 = data[0:len_2]
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if self.mode:
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C3 = data[len_2:len_3]
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C2 = data[len_3:]
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else:
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C2 = data[len_2:-64]
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C3 = data[-64:]
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xy = self._kg(int(self.private_key, 16), C1)
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# print('xy = %s' % xy)
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x2 = xy[0:self.para_len]
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y2 = xy[self.para_len:len_2]
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cl = len(C2)
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t = sm3.sm3_kdf(xy.encode('utf8'), cl/2)
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if int(t, 16) == 0:
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return None
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else:
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form = '%%0%dx' % cl
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M = form % (int(C2, 16) ^ int(t, 16))
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u = sm3.sm3_hash([
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i for i in bytes.fromhex('%s%s%s' % (x2, M, y2))
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])
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return bytes.fromhex(M)
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def _sm3_z(self, data):
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"""
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SM3WITHSM2 签名规则: SM2.sign(SM3(Z+MSG)，PrivateKey)
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其中: z = Hash256(Len(ID) + ID + a + b + xG + yG + xA + yA)
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"""
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# sm3withsm2 的 z 值
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z = '0080'+'31323334353637383132333435363738' + \
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self.ecc_table['a'] + self.ecc_table['b'] + self.ecc_table['g'] + \
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self.public_key
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z = binascii.a2b_hex(z)
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Za = sm3.sm3_hash(func.bytes_to_list(z))
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M_ = (Za + data.hex()).encode('utf-8')
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e = sm3.sm3_hash(func.bytes_to_list(binascii.a2b_hex(M_)))
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return e
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def sign_with_sm3(self, data, random_hex_str=None):
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sign_data = binascii.a2b_hex(self._sm3_z(data).encode('utf-8'))
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if random_hex_str is None:
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random_hex_str = func.random_hex(self.para_len)
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sign = self.sign(sign_data, random_hex_str) # 16进制
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return sign
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def verify_with_sm3(self, sign, data):
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sign_data = binascii.a2b_hex(self._sm3_z(data).encode('utf-8'))
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return self.verify(sign, sign_data)
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