Materias 7mo Semestre: Entrada # 6

Implementing the RSA algorithm in an HTTP (Authenticating Users)

For this week we have to implement the RSA algorithm into a web server.

Be has a user to validate your user name, for it makes use of the RSA algorithm, the server and the client need certain values (the server already has the information about your name and values of 'e' and 'n 'while the client would have' d 'and' n ').

The process would be the client requests a value of 'x' to the server, this does just that along with the link to download a script to determine the values of 'and' and 'r'.

The client downloads this file and determines the values mentioned above, then the client will provide the server user your name (as must be added, only find the name that is to avoid errors Language Script) together with the value of 'r '.

The server receives this data and using the user name extracts the values of 'e' and 'n' (for storing information this data can use files or databases) and together with the value of 'x' that provides the client.

Obtains two different 'y' (one with a specific function for us - this function is the same as in the script that I download the client - and by the formula r ^ e mod n) and compare these values, if these are the same you sends a message to the user indicating that authentication was successful.

Code in PHP

	<?php
	$Conexion = mysql_connect("localhost", "root", "pmmc.1992") or die("No poder conectar a MySQL".mysql_error());
	$Base = mysql_select_db("Cripto", $Conexion) or die("No se pudo conectar a la tabla".mysql_error());
	?>

	<?php
	function funcionx($x)
	{
	$y = (($x*$x)+(3+$x));
	return $y;
	}

	function comparay($r,$e, $n)
	{
	$y1 = 1;
	$aux = $r;
	while($e > 0)
	{
	if ($e % 2 == 1)
	{
	$y1 = ($y1 * $aux) % $n;
	}
	$aux = ($aux * $aux) % $n;
	$e = $e >> 1;
	}
	return ($y1);
	}
	?>

	<html>
	<head>
	<title>Autentificacion de Usuarios</title>
	</head>
	<body>
	<?php
	if(isset($_POST['Generar']))
	{
	$valor = rand (10, 25);
	}
	if(isset($_POST['Comprueba']))
	{
	$Quien = $_POST['User'];
	$e = mysql_fetch_row(mysql_query("SELECT e From Usuarios WHERE Nombre = \"". $Quien ."\""));
	$n = mysql_fetch_row(mysql_query("SELECT n From Usuarios WHERE Nombre = \"". $Quien ."\""));
	$e = $e[0];
	$n = $n[0];
	$x = $_POST['valex'];
	$r = $_POST['R'];
	$y = funcionx($x);
	$y1 = comparay($r,$e, $n);

	if($y==$y1)
	{
	echo "<script language='javascript'>";
	echo "alert('Usuario Validado');";
	echo "</script>";
	}else
	{
	echo "<script language='javascript'>";
	echo "alert('Usuario No Validado');";
	echo "</script>";
	}
	}
	?>

	<form action = "/RSA.php" method="post">
	X = <?php echo $valor; ?>
	//Genero Boton, nombre de variable Generar y texto Generar Reto
	<input type="submit" name="Generar" value="Generar Reto"/>
	</form>

	<form action = "/RSA.php" method="post">
	//<?php
	// $Query = mysql_query("SELECT Nombre From Usuarios");
	// $Lista = "<select name=\"NombresU\">";

	// while ($Nombre = mysql_fetch_row($Query))
	// {
	// $Lista .= "<option value='".$Nombre['Nombre']."'>".$Nombre['Nombre']."</option>";
	// }
	// $Lista .= "</select>";
	//?>
	//Usuarios disponibles: <?php echo $Lista; ?>;
	<a href="https://raw.github.com/gist/3754278/ee4497e9f8481080fca4744ef3fad070403b8af4/calculos2.py">Descargar Codigo</a>
	Nombre de usuario: <input type="text" name="User" size = "12" />
	Dame el valor de r: <input type="text" name="R" size = "12" />
	<input type = "hidden" name = "valex" value = "<?php $valor; ?>" />
	<input type = "submit" name = "Comprueba" value = "Autentificar"/>
	</form>
	</body>
	</html>

view raw RSA.php hosted with ❤ by GitHub

Script of Python

def funcion(x):

x = ((x*x)+(3+x))

return x

def fastmodexp(y, d, n):

r = 1

aux = y

while d > 0:

if d % 2 == 1:

r = (r * aux) % n

aux = (aux * aux) % n

d = d >> 1

return r

def main():

x = int(raw_input("Cual es tu x: "))

d = int(raw_input("Cual es tu d: "))

n = int(raw_input("Cual es tu n: "))

y = funcion(x)

r = fastmodexp(y, d, n)

print "Valor de r: "+str(r)

main()

view raw calculos2.py hosted with ❤ by GitHub

Code of SQL

	create table Usuarios (Nombre VARCHAR(20), e INT, n INT);

	Insert Into Usuarios Values ('Ave', 5429, 9167);
	Insert Into Usuarios Values ('Max', 73109, 233273);
	Insert Into Usuarios Values ('cecy', 89, 3649);
	Insert Into Usuarios Values ('david', 108387, 484591);
	Insert Into Usuarios Values ('Pedro', 6995, 24883);

view raw Base.sql hosted with ❤ by GitHub

Vídeo mostrando la ejecución
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Materias 7mo Semestre

Materias

jueves, 20 de septiembre de 2012

Entrada # 6

1 comentario:

	def funcion(x):
	x = ((x*x)+(3+x))
	return x

	def fastmodexp(y, d, n):
	r = 1
	aux = y
	while d > 0:
	if d % 2 == 1:
	r = (r * aux) % n
	aux = (aux * aux) % n
	d = d >> 1
	return r

	def main():
	x = int(raw_input("Cual es tu x: "))
	d = int(raw_input("Cual es tu d: "))
	n = int(raw_input("Cual es tu n: "))
	y = funcion(x)
	r = fastmodexp(y, d, n)
	print "Valor de r: "+str(r)

	main()