def get_key(n=20):
"""
获取公钥 p, g , (g^x)mod p 和私钥 x
:param n: the long of random prime
:return: p,g,y,x
"""
import pyunit_prime
p = pyunit_prime.get_large_prime_length(n)
# p = 49924286347363285385002602166419178756593347008815637398138749880304666805251999
yn = p - 1
f = 2
x_list = []
while yn != 1:
print('yn：', yn)
print('f：', f)
print(pyunit_prime.is_prime(int(yn)))
if pyunit_prime.is_prime(int(yn)):
x_list.append(int(yn))
break
if pyunit_prime.is_prime(f):
if yn % f == 0:
x_list.append(f)
while yn % f == 0:
yn = yn // f
if yn == 1:
break
f += 1
else:
f += 1
yn = p - 1
print('yn：', yn)
print('x list：', x_list)
error_list = []
import random
while True:
i = random.randint(2, p)
if i in error_list:
continue
else:
error_list.append(i)
k = 0
for j in x_list:
if fastExpMod(i, int(yn // j), p) == 1:
break
else:
k += 1
if k == len(x_list):
import random
x = random.randint(1, p - 1)
return p, i, fastExpMod(i, x, p), x
def data_encrypt(n, e, c_path, path=None, m=None):
# path = input('请输入你的文档路径:')
# D:\Workspaces\python_练习\密码学\test1.py
if path:
data_all = get_data(path)
else:
data_all = m.encode()
# n = int(input('请输入公开参数n：\t'))
# e = int(input('请输入公开参数e：\t'))
import math
data_list = standard_data(data_all, lenth=int(math.log10(n)) + 1)
m_l = []
max_len = 0
for data in data_list:
c = fastExpMod(int(data), e, n)
if c == 0:
lenth = 1
else:
lenth = int(math.log10(c)) + 1
if lenth > max_len:
max_len = lenth
m_l.append(c)
save_ctext(c_path, m_l, max_len)
return c_path, max_len
def encrypt(m, p, g, y):
"""
加密操作
c1 = g^k mod p
c2 = m*y^k mod p
:param m: 加密信息
:param p: 公开参数
:param g: 公开参数
:param y: 公开参数(g^x mod p)
:return: 密文c1和c2
"""
import random
while True:
k = random.randint(1, p - 1)
if exgcd(k, p - 1)[0] == 1:
break
c1 = fastExpMod(g, k, p)
c = fastExpMod(y, k, p)
c2 = m * c % p
return c1, c2
def decrypt(c1, c2, x, p):
"""
解密
m = c2 * (c1^x)^(-1) mod p
:param c1: 密文
:param c2: 密文
:param x: 私钥 x
:param p: 公钥p
:return: 明文 m
"""
c1 = fastExpMod(c1, x, p)
c1 = cal_inv(c1, p)
return c1 * c2 % p
def data_decrypt(n, d, c_max_len, c_path, m_path=None):
c = get_data(c_path)
import math
m_list = ''
lenth = 0
for m in c:
lenth += 1
if lenth == len(c):
m_list += str(m)
elif m == 0:
m_list += '00'
else:
m_list += '0' * (1 - int(math.log10(m))) + str(m)
c = m_list
c = list_split(c, c_max_len)
if len(c[len(c) - 1]) < c_max_len:
c[len(c) - 1] += c[len(c) - 1][len(c[len(c) - 1]) - 1]
c[len(c) - 1][len(c[len(c) - 1]) - 1] = '0'
res = ''
for data in c:
m = fastExpMod(int(data), d, n)
res += str(m)
m = recovery_data(res)
if m_path:
makefile(m_path, m)
return m_path
else:
m_s = bytes()
for data in m:
m_s += data.to_bytes(1, 'little')
return m_s.decode()