password.texy translated in english (#500)

Author: lukasneubauer

doc/en/passwords.texy

@@ -0,0 +1,49 @@
+Working With Passwords - Nette\Security\Passwords
+*************************************************
+
+.[perex]
+To manage security of our users, we never save their passwords in plaintext format, but we rather save the password´s fingerprint (eg. hash). There is no way to find out the real password from the password´s fingerprint. To create the fingerprint we have to use a save algorithm. Static class [Nette\Security\Passwords |api:] will help us with this.
+
+Following examples expect this alias:
+
+/--php
+use Nette\Security\Passwords;
+\--
+
+
+hash($passwords, array $options = NULL)
+=======================================
+
+This method generates password´s hash using a modern bcrypt algorithm. We can set the `cost` parameter of range 4-31, which sets the number of iterations the algorithm takes to run. If we omit this parameter, a default value of `10` will be used.
+
+.[warning]
+The `cost` parameter is an exponent of function 2^n. If we set its value too high, the hash computation will take too long. By using the highest value of 31 the compuauion takes approximately 64 hours.
+
+/--php
+$hash = Passwords::hash($password); // Hashes the password
+$hash = Passwords::hash($password, ['cost' => 12]); // Hashes the password using 12 iterations of bcrypt algorithm
+\--
+
+verify($password, $hash)
+========================
+
+This method finds out, if given password matches given fingerprint (hash).
+
+/--php
+if (Passwords::verify($password, $hash)) {
+	// This will run, if password matches the fingerprint (hash)
+} else {
+	// This will run, if password does not match the fingerprint (hash)
+}
+\--
+
+needsRehash($password, array $options = NULL)
+=============================================
+
+This method finds out, if the hash matches given options. We can set the `cost` parameter of range 4-31, which sets the number of iterations the algorithm takes to run. If we omit this parameter, a default value of `10` will be used.
+
+/--php
+if (Passwords::needsRehash($hash)) {
+	// This will run, if the password needs to be rehashed
+}
+\--