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| from gmpy2 import invert
import sm3, key
from random import choice
random_hex = lambda x: ''.join([choice('0123456789abcdef') for _ in range(x)])
default_ecc_paras = {
'p' : 0x8542D69E4C044F18E8B92435BF6FF7DE457283915C45517D722EDB8B08F1DFC3,
'a' : 0x787968B4FA32C3FD2417842E73BBFEFF2F3C848B6831D7E0EC65228B3937E498,
'b' : 0x63E4C6D3B23B0C849CF84241484BFE48F61D59A5B16BA06E6E12D1DA27C5249A,
'G' : (0x421DEBD61B62EAB6746434EBC3CC315E32220B3BADD50BDC4C4E6C147FEDD43D,
0x0680512BCBB42C07D47349D2153B70C4E5D7FDFCBFA36EA1A85841B9E46E09A2),
'n' : 0x8542D69E4C044F18E8B92435BF6FF7DD297720630485628D5AE74EE7C32E79B7,
}
zero_point = (0, 0)
class SM2(object):
def __init__(self, private_key, public_key, ecc_paras = default_ecc_paras):
self.private_key = private_key
self.public_key = public_key
self.ecc_paras = ecc_paras
self.para_len = 64
def add_point(self, P1, P2):
if P1 == zero_point:
return P2
if P2 == zero_point:
return P1
(p1x, p1y), (p2x, p2y) = P1, P2
if p1x == p2x and (p1y != p2y or p1y == 0):
return zero_point
if p1x == p2x:
lam = (3 * p1x * p1x + self.ecc_paras['a']) * invert(2 * p1y , self.ecc_paras['p']) % self.ecc_paras['p']
else:
lam = (p2y - p1y) * invert(p2x - p1x , self.ecc_paras['p']) % self.ecc_paras['p']
x = (lam**2 - p1x - p2x) % self.ecc_paras['p']
y = (lam * (p1x - x) - p1y) % self.ecc_paras['p']
return (int(x),int(y))
def get_kg(self, k, P):
tmp = zero_point
while(k):
if(k & 1):
tmp = self.add_point(tmp, P)
P = self.add_point(P, P)
k >>= 1
form = '%%0%dx' % self.para_len
form = form * 2
return form % (tmp[0], tmp[1])
def sign(self, data):
e = int(data.hex(),16)
s = 0
r = 0
while s == 0:
while r == 0 or r + k == self.ecc_paras['n']:
k = int(random_hex(self.para_len), 16)
xy = self.get_kg(k, self.ecc_paras['G'])
x = int(xy[:self.para_len], 16)
y = int(xy[self.para_len:], 16)
r = (e + x) % self.ecc_paras['n']
s = (k - r * self.private_key) * invert(self.private_key + 1, self.ecc_paras['n']) % self.ecc_paras['n']
return '%064x%064x' % (r, s)
def verify(self, sign, data):
r = int(sign[:self.para_len], 16)
s = int(sign[self.para_len:], 16)
assert r >= 1 and r <= self.ecc_paras['n'] - 1
assert s >= 1 and s <= self.ecc_paras['n'] - 1
e = int(data.hex(), 16)
t = (r + s) % self.ecc_paras['n']
if t == 0:
print('验证失败！')
return None
P1 = self.get_kg(s, self.ecc_paras['G'])
P2 = self.get_kg(t, self.public_key)
x, y = self.add_point((int(P1[:self.para_len], 16),int(P1[self.para_len:], 16)),
(int(P2[:self.para_len], 16),int(P2[self.para_len:], 16)))
R = (e + x) % self.ecc_paras['n']
return R == r
def encrypt(self, data):
msg = data.hex()
k = int(random_hex(self.para_len),16)
C1 = self.get_kg(k, self.ecc_paras['G'])
xy = self.get_kg(k, self.public_key)
x2 = xy[0:self.para_len]
y2 = xy[self.para_len:2*self.para_len]
mlen = len(msg)
t = sm3.sm3_kdf(xy, mlen/2)
if int(t, 16) == 0:
return None
form = '%%0%dx' % mlen
C2 = form % (int(msg, 16) ^ int(t, 16))
C3 = sm3.sm3_hash([i for i in bytes.fromhex('%s%s%s' % (x2, msg, y2))])
return bytes.fromhex('%s%s%s' % (C1, C3, C2))
def decrypt(self, data):
data = data.hex()
len_2 = 2 * self.para_len
len_3 = len_2 + 64
C1 = data[0:len_2]
C1x = int(C1[:self.para_len],16)
C1y = int(C1[self.para_len:],16)
assert C1y**2 % self.ecc_paras['p'] == (C1x**3 + self.ecc_paras['a'] * C1x + self.ecc_paras['b']) % self.ecc_paras['p']
C3 = data[len_2:len_3]
C2 = data[len_3:]
xy = self.get_kg(self.private_key,(C1x, C1y))
x2 = xy[0:self.para_len]
y2 = xy[self.para_len:len_2]
cl = len(C2)
t = sm3.sm3_kdf(xy, cl/2)
if int(t, 16) == 0:
return None
form = '%%0%dx' % cl
M = form % (int(C2,16) ^ int(t,16))
u = sm3.sm3_hash([i for i in bytes.fromhex('%s%s%s'% (x2,M,y2))])
return bytes.fromhex(M)
def sign_and_verify():
sk1, pk1 = key.gen_key()
sm2_user = SM2(sk1, pk1)
data = b'sh1kaku'*100
sign_data = sm2_user.sign(data)
print(sm2_user.verify(sign_data, data))
print()
def encrypt_and_decrypt():
sk1, pk1 = key.gen_key()
sm2_user = SM2(sk1, pk1)
data = b'sh1kaku'*100
en = sm2_user.encrypt(data)
print('加密后：', en)
de = sm2_user.decrypt(en)
print('解密：', de)
sign_and_verify()
encrypt_and_decrypt()
|