#week number 5

This time, the homewoork is a simple server -  client with protocole rsa


Firsth the client try to conect to client
when the server detecte  the conexion of client start the protocole

1-. the server send x to client
2-. the client send messege encrupte
3-. the server desencripte and compere the y of server with the cliente
4-. if its the same the sounds is good
5-. if its different its to bad :C


We created two base data
one for user
one for the publi keys

The code of server:

	import socket #import librery for sockets
	import random #import librery for random numers
	s = socket.socket()
	s.bind(("localhost",9999))
	s.listen(10) ##accept maxim conexion
	n = 0
	x = random.randint(1, 50)
	y = 0
	res= 0
	a = 0
	d = 0
	print "Esperamos que alguien se conecte"
	sc, addr = s.accept() ##host y direccion and waiting conexion
	print "Se trata de conectar alguien"
	#def funcion:
	base = open("usuario.dat","r")##base data user
	llave = open("llaves.dat","r")##base data private
	#funcion for verific user#
	def verificar(recivido):
	for i in base.xreadlines():
	dato = i
	x = 0
	print "dato = ",dato
	tam = len(dato)
	print "recivido = ",recivido
	if str(recivido) == str(dato):
	print "si eres tu xD"
	break
	else:
	"no eres tu xD"
	##funcion for read keys
	def llaves():
	global d
	global n
	for i in llave.xreadlines():
	tam = len(i)
	d = int(i[0])
	n = 14
	##funcion for send messege to client
	def enviar():
	print "numero que ando enviando: ",x
	sc.send(str(x))
	##funcion for recive messege of client
	def recivir():
	global res
	llaves()
	print "e = ",d
	print "n = ",n
	recibido = int(sc.recv(1024))
	print "recibodo r= ", recibido
	res = recibido
	##calculate "y" of client with the private keys
	a = pow(res,d) % n
	#messege desencript#
	print "Y=",a
	#funcion of y#
	def funcion():
	global y
	y = x
	print "yyyy",y
	#process of comunication#
	while True:
	if n == 0:
	enviar()
	n = 1
	if n == 1:
	print "esperando respuesta"
	funcion()
	recivir()
	n = 2
	if n == 2:
	print "espero respuesta:"
	recibido = sc.recv(1024)
	print "tu nombre es: ",recibido
	verificar(recibido)
	n = 3
	print "adios"
	sc.close()##close client
	s.close() ##close server

view raw server.py hosted with ❤ by GitHub

The code of client:

	import socket #import sockers for client
	s = socket.socket() #declared objets
	s.connect(("localhost",9999)) ##conect to server
	n = 0
	y = 0
	x = 0
	print "1 Conectarte \n 2 Salida"
	decision = raw_input("Que deseas hacer:")
	print decision
	##funcion of x
	def funcion():
	global y
	y = a
	print y
	##for probabli conexion
	if decision == "1":
	while True:
	if n == 0:
	#reciv x#
	x = s.recv(1024)
	a = int(x)
	print a
	n = 1
	if n == 1:
	print "funcion = "
	funcion()
	##send d an n to server
	d = int(raw_input("dame la cosa d"))
	n = int(raw_input("dame la cosa n"))
	##send messeng codificat
	r = str(pow(y,d) % n)
	print "valor de r",r
	s.send(r)
	n = 2
	if n == 2:
	##send user
	usuario = raw_input("dame tu nombre: ")
	s.send(usuario)
	print "espero mensaje"
	x = s.recv(1024)
	n = 3
	else:
	print "adios"
	s.close() #close client

view raw client.py hosted with ❤ by GitHub

The code of generet keys:

	import random ##import mmodul random
	p = 0
	q = 0
	n = 0
	modul = 0
	c = []
	a = []
	b = []
	d = []
	z = []
	##funcion for comprobet if some numer is prime
	def primo(x):
	global n
	i = 0
	c = 0
	while i < (x - 1):
	i = i + 1
	residuo = x % i
	if residuo==0:
	c=c+1
	if c>=2:
	print "no es primo: ",x
	else:
	if x==1:
	print "es uno xD"
	else:
	print "EL numero si es primo ",x
	n = n + 1
	return x
	while n < 2:
	if n ==1 :
	p = random.randint(1, 10)
	a1 = primo(p)
	else:
	q = random.randint(1, 10)
	b1 = primo(q)
	si = 0
	##funcion to comprobet if two numer is coprime
	def gcd(en,e):
	global si
	global modul
	modul = en % e
	if modul == 0:
	print "maximo factor de los numeros"
	print "maximo factor = ",e
	#if modul == 1:
	# print "si son primos entre si: ",modul
	else:
	if modul == 1:
	print "si son primos entre si"
	si = 1
	else:
	if modul != 0:
	en = e
	e = modul
	gcd(en,e)
	##funcio to found ecuacion for eculides
	def euclides(en,e):
	x = en
	y = e
	modul = x % y
	divi = x / y
	print "resultado de la divicion",divi
	print "sobrante ",modul
	a.append(x)
	b.append(y)
	x = y
	y = modul
	c.append(divi)
	d.append(modul)
	if modul == 0:
	print "termio"
	print c
	print modul
	else:
	euclides(x,y)
	print "a= ",a
	print "b = ",b
	print "c = ",c
	print "d= ",d
	##codigo in general to found n,e,phi
	while si < 1:
	while n < 2:
	if n == 0:
	p = random.randint(1, 100)
	a1 = primo(p)
	if n ==1:
	q = random.randint(1, 100)
	b1 = primo(q)
	n = a1*b1
	en = (a1-1)*(b1-1)
	print "N = ",n
	print "en =",en
	e = random.randint(1,(en -1))
	print "valor de e:",e
	gcd(en,e)
	print modul
	euclides(n,e)
	##this code i found in i used this only for comprobate my result in paper
	##only this no my :C
	##link where i found this: http://www.slideshare.net/jpadillaa/criptografia-asimetrica-rsa
	#sorry for this :C
	#def egcd(a,b):
	# u,u1=1,0
	# v,v1 =0,1
	# while b:
	# q = a//b
	# u,u1 = u1,u -q*u1
	# v,v1 =v1,v-q*v1
	# a,b = b,a-q*b
	# return u,v,a
	#def modInverse(e,n):
	# return egcd(e,n)[0]%n
	#d = modInverse(13,25)
	#print "deeee=",d

view raw genere.py hosted with ❤ by GitHub

hire som image for some calcule of "d"

Some print screen

hire d = 3

N = 35

e = 23

The client sends a "d" and "n" and the server before it sends an x to use the function (x) and the client send its function, if  we are see where it says yyyy = 16 is the calculation server and Y is the calculation using the keys in this case, will leave the program.

In this image is about the code generet keys, this  generet value n,e,phie and verific if the numers are coprime, for used in ecuclides algoritm in paper :C

Links reference:

http://es.wikipedia.org/wiki/RSA

http://es.wikipedia.org/wiki/Algoritmo_de_Euclides

http://www.slideshare.net/jpadillaa/criptografia-asimetrica-rsa

http://es.wikipedia.org/wiki/N%C3%BAmeros_primos_entre_s%C3%AD

http://enciclopedia.us.es/index.php/N%C3%BAmeros_coprimos

http://mundogeek.net/archivos/2008/04/12/sockets-en-python/

http://wiki.python.org/moin/HowTo/Sockets