Information security and cryptography: septiembre 2012

jueves, 20 de septiembre de 2012

week number 6

In this week, we need to aplicated a serves web with rsa system

Some introdcuccin

In the web serves some peple for example alice generetd "X" and seend this a Bob.
Bob will dowload some script to put him privated keys and the x, before bob sends result "r", and alice put the result in the serves and user, finaly the serves says if bob is bob or not

Code1 :

	<html>
	<head>
	<title>Sistem of autentification</title>
	</head>
	<body>


	<H1>Download script python</H1>
	<a href= script.py target=_blank><button>clic here</button></a>

	<?php
	//generet random "x"
	$num=rand(1,50);
	$variable=rand(1,50);
	?>

	<p>
	<?php
	//Send with method reference the value of x
	?>
	<H1>Challenge:</H1>
	<a href="accion.php?var=<?php echo $variable; ?>"/>
	<p><input type="submit" VALUE="send"/></p>
	</p>


	</body>

view raw index.php hosted with ❤ by GitHub

Code2:

	Value of x:
	<?php
	//obtain value of x and
	// show value of x
	$num = $_GET["var"];
	echo $num;
	?>

	<?php
	//send values of user, r and value of x for future algoritms
	?>
	<H1>Verification:</H1>
	<FORM ACTION="verificar.php" METHOD="GET">
	Value of r: <INPUT TYPE="text" NAME="r"><BR>
	User name: <INPUT TYPE="text" NAME="usuario"><BR>
	<input type="hidden" name="x" value="<?php echo $num; ?>">
	<INPUT TYPE="submit" VALUE="Enviar">
	</FORM>

view raw accion.php hosted with ❤ by GitHub

Code3:

	<html>
	<head>
	<title>Verification</title>
	</head>
	<body>

	value of y =
	<?php
	//Calculated value of y
	$a = 3;
	$num = $_GET['x'];
	$numy = $num + $a;
	echo $numy;
	?>


	<H1>Verification</H1>
	The name you entered is : <?php echo $_GET['usuario'] ?>
	R: <?php echo $_GET['r'] ?>
	Valor de x: <?php echo $_GET['x'] ?>
	<br>



	<?php
	//read some file.dat to found user and the keys
	$filas=file('user.dat');
	// array about the values
	$campos = array('id', 'e', 'n');
	$c = 0;
	$cadena = $_GET['usuario'];
	$lugar = 0;
	$e = 0;
	$n = 0;

	//iterator about array in this case the line of file
	foreach($filas as $v){
	//save array after for some separation o caracter in this case ","
	$datos=explode(",",$v);
	//iterate arrays about the line with the separation
	foreach($datos as $dato){
	//comparate the user(cadena) vs line
	if(strcmp($dato, $cadena) != 0) {
	//echo "User was not found";
	}
	else
	{
	echo "User was found";
	//if found save the information in some variable
	$e = $datos[1];
	$n = $datos[2];
	}
	$c++;
	}
	$c = 0;
	echo "<p />";

	}
	?>



	<?php
	//process about the verification
	$r = $_GET['r'];

	//algoritmy to calculated the module
	$lle = 1;
	$u = $r % $n;

	while ($e > 0)
	{
	if(($e % 2) == 1)
	{
	$lle = ($lle*$u) % $n;
	}
	$e = $e/2;
	$u = ($u*$u) % $n;
	}
	//algoritmy to calculated the module


	if ($numy == $lle)
	{
	echo "its really him/her";
	}
	else
	{
	echo " is not him/her";
	}

	?>


	</body>
	</html>

view raw verification.php hosted with ❤ by GitHub

Script of dowload:

	y = 0
	r = 0
	d = 0
	x = 0

	##funcion of f(x)
	def funcionx(x):
	global y
	y = x + 3
	##funcion to obtain r with Modular exponentiation algorithm i used this method to

	##calculated r and desencript messenge in the php. Reference link about the

	##algoritm: http://web.usal.es/~hernando/segi2012/11HerrMat.pdf

	def funcionr():
	global r,d,n,y
	lle = 1
	u = y % n

	while (d > 0):
	if((d % 2) == 1):
	lle = (lle*u) % n
	d = d/2
	u = (u*u) % n
	r = lle


	def main():
	global d,n
	print "Dar valores de tu clave privada: "
	x = int(raw_input("Dame el valor de x: "))
	d = int(raw_input("Dame el valor de d: "))
	n = int(raw_input("Dame el valor de n: "))
	funcionx(x)
	funcionr()
	print "Valor de y = ",y
	print "Valor de r:",r

	main()

view raw script.py hosted with ❤ by GitHub

Screen4:

Ramón used my server some pictures:

and triana (in this case was not yet translated)

Link of servece: http://alejandroave.260mb.org/
Apologies for publicity :C but "ITS FREE"

Reference:
http://php.net/manual/es/control-structures.foreach.php
http://php.net/manual/es/function.explode.php
http://php.net/manual/es/tutorial.php
http://web.usal.es/~hernando/segi2012/11HerrMat.pdf

jueves, 13 de septiembre de 2012

#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