Client.py
from socket import *
from threading import Thread
from Crypto.Cipher import AES
# f is for opening the file and reading the binary data
# that I later want to send to another client
f = open('book.epub', 'rb')
# f2 is to see if there is anything wrong with my method of writing
# So I open the file f2 in 'wb' mode and later encrypt everything I read
# from f and then decrypt it so that I can see if the encryption /
# decryption method changes any of the bytes
f2 = open('example.epub', 'wb')
# Used to encrypt messages
def encrypting(message):
obj = AES.new('This is a key123', AES.MODE_CFB, 'This is an IV456')
ciphertext = obj.encrypt(message)
return ciphertext
# Used to decrypt messages
def decrypting(ciphertext):
obj2 = AES.new('This is a key123', AES.MODE_CFB, 'This is an IV456')
message = obj2.decrypt(ciphertext)
return message
def main():
s = socket()
s.connect(('localhost', 15000))
# Now I'm connected to the localhost at port 15000
# Reads 512 charactes of file "f" and
# Make data equal those characters
data = f.read(512)
# While data that I'm reading is not empty, write data to file f2
# and encrypt it so it can be securely sent
# When I've read the whole file "f", the data variable becomes empty
# And the while loop ends
while data:
data = encrypting(data)
data = decrypting(data)
# I do an encryption and decryption to make sure
# That there is nothing wrong with the process.
# If I can't open the file "f2" after the program is done
# then I can't possibly open the file I just send to another
# computer, so I just double check
print('Writing data: ' + str(data))
f2.write(data)
# Encrypts data after making sure that the data
# Is not mangled during encryption / decryption
data = encrypting(data)
# Sending encrypted data to server
s.send(data)
# Reading the next 512 characters of file f
data = f.read(512)
# Closing all the open streams
s.close()
f.close()
f2.close()
if __name__ == '__main__':
main()
Server.py
from socket import *
from threading import Thread
from Crypto.Cipher import AES
# Opening file "fi", which is the file I will be writing
# All the binary data I've received from the client
fi = open('trash.epub', 'wb')
# Used to encrypt the data
def encrypting(message):
obj = AES.new('This is a key123', AES.MODE_CFB, 'This is an IV456')
ciphertext = obj.encrypt(message)
return ciphertext
# Used to decrypt the received data
def decrypting(ciphertext):
obj2 = AES.new('This is a key123', AES.MODE_CFB, 'This is an IV456')
message = obj2.decrypt(ciphertext)
return message
def client_handler():
conn, addr = s.accept()
print(str(addr) + ' connected!')
# Continues until data is empty
while True:
# Listens and receives a whopping 4096
data = conn.recv(4096)
# Breaks is data send is empty
# Client send empty data when reading past the file lengt
# Hence the file reading and sending is complete
if data == b'':
conn.close()
break
# Decrypting the encrypted data
data = decrypting(data)
# Printing the data the program is about to write
# As well as it's type, just for debug purposes
print('Writing: ' + str(data) + '\n\n')
print('Type: ' + str(type(data)))
# Writes the decrypted binary data received from the client
fi.write(data)
# Closes streams
fi.close()
s.close()
HOST = "localhost"
PORT = 15000
# Initializing the server on
# the address: localhost
# and the port: 15000
s = socket(AF_INET, SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(4)
print("Server is runnig")
# Executes the client_handler(), which listens to incoming data
client_handler()
Когда я пытаюсь открыть trash.epub с помощью mupdf (я нахожусь в Arch Linux), я получаю сообщение об ошибке::
error: zlib inflate error: invalid distance too far back
Файлы book.epub и example.epub работают без проблем, но trash.epub - это просто ... мусор.Файл «trash.epub» имеет тот же размер файла, что и два других.Когда я ввожу
nano book.epub
При вводе nano trash.epub обнаруживаются те же данные, такое же количество строк, одинаковое количество символов. Тем не менее, я не могу открыть trash.epub.Я могу открыть example.epub без проблем, но что-то не так с trash.epub.Есть идеи?