import random

import hashlib

import math

import tkinter as tk

# Create a Tkinter window

window $=$ tk$.$Tk$()$

window.title$("$RSA Encryption and Decryption"$)$

# Create a text box for entering the message

message$\_$entry $=$ tk$.$Entry$($window$)$

message$\_$entry.pack$()$

# Example usage function with modifications to update the GUI

def example$\_$usage$()$:

message $=$ message$\_$entry.get$()$

# Generate prime numbers p and q

p $=$ generate$\_$prime$\_$number$()$

q $=$ generate$\_$prime$\_$number$()$

# Calculate n and phi$($n$)$

n $=$ p $*$ q

phi$\_$n $=($p $-1)*($q $-1)$

# Find encryption key $($e$)$

e $=$ euclid$\_$algorithm$($phi$\_$n$)$

# Find decryption key $($d$)$

d $=$ extended$\_$euclid$\_$algorithm$($e$,$ phi$\_$n$)$

# Encrypt the message

ciphertext $=$ encrypt$($message$,$ e$,$ n$)$

# Decrypt the ciphertext

decrypted$\_$message $=$ decrypt$($ciphertext$,$ d$,$ n$)$

# Update the results label

results$\_$label.config$($text$=$f$"$Original Message: $\{$message$\}$

Encrypted Message: $\{$ciphertext$\}$

Decrypted Message: $\{$decrypted$\_$message$\}")$

# Create a button to perform encryption and decryption

encrypt$\_$decrypt$\_$button $=$ tk$.$Button$($window$,$ text$=$"Encrypt and Decrypt", command$=$example$\_$usage$)$

encrypt$\_$decrypt$\_$button.pack$()$

# Create a label to display the results

results$\_$label $=$ tk$.$Label$($window$)$

results$\_$label.pack$()$

# Generate prime numbers p and q

def generate$\_$prime$\_$number$()$:

while True:

num $=$ random.randint$(2**15,2**16)$ # Adjust the range as per your requirements

if is$\_$prime$($num$)$:

return num

# Miller$-$Rabin primality testing

def is$\_$prime$($num$)$:

if num $==2$ or num $==3$:

return True

if num $<2$ or num $\%2==0$:

return False

r$,$ s $=0,$ num $-1$

while s $\%2==0$:

r $+=1$

s $//=2$

for $\_$ in range$(5)$: # Adjust the number of iterations for desired accuracy

a $=$ random.randint$(2,$ num $-1)$

x $=$ pow$($a$,$ s$,$ num$)$

if x $==1$ or x $==$ num $-1$:

continue

for $\_$ in range$($r $-1)$:

x $=$ pow$($x$,2,$ num$)$

if x $==$ num $-1$:

break

else:

return False

return True

# Euclid's algorithm to find the encryption key $($e$)$

def euclid$\_$algorithm$($phi$\_$n$)$:

while True:

e $=$ random.randint$(2,$ phi$\_$n$)$

if math.gcd$($e$,$ phi$\_$n$)==1$:

return e

# Extended Euclid's algorithm to find the decryption key $($d$)$

def extended$\_$euclid$\_$algorithm$($e$,$ phi$\_$n$)$:

d $=0$

x$1,$ x$2,$ y$1,$ y$2=0,1,1,0$

temp$\_$phi$\_$n $=$ phi$\_$n

while e $>0$:

temp$1=$ temp$\_$phi$\_$n $//$ e

temp$2=$ temp$\_$phi$\_$n $-$ temp$1*$ e

temp$\_$phi$\_$n $=$ e

e $=$ temp$2$

x $=$ x$2-$ temp$1*$ x$1$

y $=$ y$2-$ temp$1*$ y$1$

x$2=$ x$1$

x$1=$ x

y$2=$ y$1$

y$1=$ y

if temp$\_$phi$\_$n $==1$:

d $=$ y$2$

if d $<0$:

d $+=$ phi$\_$n

return d

# Hash function

def hash$\_$message$($message$)$:

sha$256=$ hashlib.sha$256()$

sha$256.$update$($message$.$encode$(\text{'}$utf$-8\text{'}))$

return sha$256.$digest$()$

# RSA encryption

def encrypt$($message$,$ e$,$ n$)$:

numeric$\_$message $=$ int.from$\_$bytes$($message$.$encode$(),$ 'big'$)$

return pow$($numeric$\_$message, e$,$ n$)$

# RSA decryption

def decrypt$($ciphertext$,$ d$,$ n$)$:

numeric$\_$ciphertext $=$ pow$($ciphertext$,$ d$,$ n$)$

decrypted$\_$bytes $=$ numeric$\_$ciphertext.to$\_$bytes$(($numeric$\_$ciphertext.bit$\_$length$()+7)//8,$ 'big'$)$

decrypted$\_$message $=""$

for byte in decrypted$\_$bytes:

try:

decrypted$\_$message $+=$ chr$($byte$)$

except UnicodeDecodeError:

decrypted$\_$message $+=$ f$"[$Byte $\{$byte$\}]"$

return decrypted$\_$message

# Digital signature signing

def sign$($message$,$ d$,$ n$)$:

hashed$\_$message $=$ hash$\_$message$($message$)$

signature $=$ pow$($int$.$from$\_$bytes$($hashed$\_$message, 'big'$),$ d$,$ n$)$

return signature

# Digital signature verifying

def verify$($message$,$ signature, e$,$ n$)$:

hashed$\_$message $=$ hash$\_$message$($message$)$

decrypted$\_$signature $=$ pow$($signature$,$ e$,$ n$)$

return int.from$\_$bytes$($hashed$\_$message, 'big'$)==$ decrypted$\_$signature

# Run the Tkinter event loop

window.mainloop$()$