RSA加密算法 python实现

 import PySimpleGUI as sg

    
  
    
 # 拓展欧几里得算法求最大公约数
    
 def ex_gcd(a,b,arr):
    
     if b == 0:
    
     arr[0] = 1
    
     arr[1] = 0
    
     return a
    
     r = ex_gcd(b,a%b,arr)
    
     tmp = arr[0]
    
     arr[0] = arr[1]
    
     arr[1] = tmp - int(a/b)*arr[1]
    
     return r
    
  
    
 # 将最大公因数回代 辗转相除法回代求得模逆
    
 def get_d(a,b):
    
     arr = [0,0]
    
     r = ex_gcd(a,b,arr)
    
     if r == 1:
    
     return int((arr[0]%b+b)%b)
    
     else:
    
     return -1
    
  
    
 # 求解a^b % r 用平方乘（快速幂算法）
    
 def fast_power(a,b):
    
     if b == 0:
    
     return 1
    
     else:
    
     ans = 1
    
     while b > 0:
    
         if b % 2 == 1:
    
             ans = ans * a
    
         a = a * a
    
         b = b // 2
    
     return ans
    
  
    
 # 加密
    
 def encrypt(m,e,n):
    
     c = fast_power(m,e) % n
    
     return c
    
  
    
 # 解密
    
 def decrypt(c,d,n):
    
     m = fast_power(c,d) % n
    
     return m
    
  
    
  
    
 layout = [
    
     [sg.T('请输入两个大的素数',size=(15)),sg.In(key='-sushu-',focus=True)],
    
     [sg.T('请输入您的公钥',size=(15)),sg.In(key='-pk-')],
    
     [sg.B('产生密钥'),sg.In(key='-sk-',size=(54),disabled=True)],
    
     [sg.T('请输入明文(整数)',size=(15)),sg.In(key='-P-')],
    
     [sg.T('加密后的密文',size=(15)),sg.In(key='-C-',disabled=True)],
    
     [sg.T('解密输出后的明文',size=(15)),sg.In(key='-RES-',disabled=True)],
    
     [sg.B('加密'),sg.B('解密'),sg.B('重置')]
    
 ]
    
  
    
 window = sg.Window('RSA算法演示程序',layout)
    
  
    
 while 1:
    
     event, values = window.read()
    
     # print(values)
    
     if event == None:
    
     break
    
  
    
     if event == '产生密钥':
    
     if values['-sushu-'] == '' or values['-pk-'] == '':
    
         sg.Popup('提示', '请输入素数和私钥！', title='提示')
    
     else:
    
         p, q = map(int, values['-sushu-'].split())
    
         e = int(values['-pk-'])
    
         n = p * q
    
         r = (p - 1) * (q - 1)
    
         d = get_d(e, r)
    
         window['-sk-'].update(value='公钥为{e,n}={'+str(e)+','+str(n)+'}  私钥为{d,n}={'+str(d)+','+str(n)+'}')
    
  
    
  
    
     if event == '加密':
    
     if values['-P-'] == '' or values['-sushu-'] == '' or values['-pk-'] == '':
    
         sg.Popup('提示', '请自己实现加密函数！', title='提示')
    
     else:
    
         m = int(values['-P-'])
    
         p, q = map(int, values['-sushu-'].split())
    
         e = int(values['-pk-'])
    
         n = p * q
    
         c = encrypt(m, e, n)
    
         window['-C-'].update(value=c)
    
  
    
     if event == '解密':
    
     if values['-C-'] == '':
    
         sg.Popup('提示', '请自己实现解密函数！', title='提示')
    
     else:
    
         c = int(values['-C-'])
    
         p, q = map(int, values['-sushu-'].split())
    
         e = int(values['-pk-'])
    
         n = p * q
    
         r = (p - 1) * (q - 1)
    
         d = get_d(e, r)
    
         m = decrypt(c, d, n)
    
         window['-RES-'].update(value=m)
    
  
    
     if event == '重置':
    
     for item in values:
    
         window[item].update(value='')
    
     window['-sushu-'].SetFocus()
    
  
    
 window.close()

 # 输入(a为底数 n为指数 b为模数) 输出就是表达式的值

    
 def fast_power(a,n,b):
    
     ans = 1
    
     base = a
    
     while n != 0:
    
     if n & 1 != 0:
    
         ans *= base
    
     base *= base
    
     n >>= 1
    
     return ans % b