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Category Archives for "Networking"

Saving a Cloonix network topology

The Cloonix network simulator has been updated to version 29, which adds the ability to save network simulation topologies and node configurations to a directory.

Users may save a network topology and all node configurations to a directory of their choice. They may also load saved topologies into Cloonix so they can restore a network scenario they previously created. The save function of Cloonix v29 supports copy-on-write filesystems and also allows users to save the full filesystems of nodes, if they wish.

This post will work through a detailed tutorial showing how to save, load, and re-save topologies and node configurations using the Cloonix GUI or command-line interface.

Different methods to save a Cloonix project

In this tutorial we will show three ways Cloonix may be used to save filesystems and network topologies:

  1. Create a new base filesystem by starting a VM in Cloonix, loading software and configurations, then saving either a full VM disk image or a derived VM disk image.
    • This simple case is useful when upgrading or modifying disk images that will be used in simulation scenarios.
       
  2. Start the Cloonix graph, set up the VMs, load software, and configure them. Then save the topology and filesystems.

Can You Keep a Secret? (Part 2)

In part one, we saw how AES can be used to encrypt sensitive data so that it can be retrieved only by using an encryption key. The problem with this approach is that everyone who needs access to the data must have a copy of the key. If any one of these copies becomes compromised, the entire database must be re-encrypted using a new key, and the new key must be distributed securely to all parties involved. In this article, we'll see how symmetric encryption can be combined with asymmetric cryptography (namely RSA) to create a hybrid cryptosystem.

Let's begin by encrypting some data using AES as we did in part one. First we pad our plaintext's length to a multiple of 16 using null bytes, then generate a 256-bit encryption key and a 128-bit IV, and finally encrypt it with CFB-mode AES to generate a string of ciphertext.

>>> from Crypto.Cipher import AES
>>> import os
>>> plaintext = "Operation Neptune will launch on June 6th"
>>> plaintext += (16 - len(plaintext) % 16) * chr(0)
>>> encryption_key = os.urandom(32)
>>> iv = os.urandom(16)
>>> cipher = AES.new(encryption_key, AES.MODE_CFB, iv)
>>> ciphertext =  Continue reading

Can You Keep a Secret? (Part 2)

In part one, we saw how AES can be used to encrypt sensitive data so that it can be retrieved only by using an encryption key. The problem with this approach is that everyone who needs access to the data must have a copy of the key. If any one of these copies becomes compromised, the entire database must be re-encrypted using a new key, and the new key must be distributed securely to all parties involved. In this article, we'll see how symmetric encryption can be combined with asymmetric cryptography (namely RSA) to create a hybrid cryptosystem.

Let's begin by encrypting some data using AES as we did in part one. First we pad our plaintext's length to a multiple of 16 using null bytes, then generate a 256-bit encryption key and a 128-bit IV, and finally encrypt it with CFB-mode AES to generate a string of ciphertext.

>>> from Crypto.Cipher import AES
>>> import os
>>> plaintext = "Operation Neptune will launch on June 6th"
>>> plaintext += (16 - len(plaintext) % 16) * chr(0)
>>> encryption_key = os.urandom(32)
>>> iv = os.urandom(16)
>>> cipher = AES.new(encryption_key, AES.MODE_CFB, iv)
>>> ciphertext =  Continue reading

Can You Keep a Secret? (Part 2)

In part one, we saw how AES can be used to encrypt sensitive data so that it can be retrieved only by using an encryption key. The problem with this approach is that everyone who needs access to the data must have a copy of the key. If any one of these copies becomes compromised, the entire database must be re-encrypted using a new key, and the new key must be distributed securely to all parties involved. In this article, we'll see how symmetric encryption can be combined with asymmetric cryptography (namely RSA) to create a hybrid cryptosystem.

Let's begin by encrypting some data using AES as we did in part one. First we pad our plaintext's length to a multiple of 16 using null bytes, then generate a 256-bit encryption key and a 128-bit IV, and finally encrypt it with CFB-mode AES to generate a string of ciphertext.

>>> from Crypto.Cipher import AES
>>> import os
>>> plaintext = "Operation Neptune will launch on June 6th"
>>> plaintext += (16 - len(plaintext) % 16) * chr(0)
>>> encryption_key = os.urandom(32)
>>> iv = os.urandom(16)
>>> cipher = AES.new(encryption_key, AES.MODE_CFB, iv)
>>> ciphertext =  Continue reading

Change the (S)Channel! Deconstructing the Microsoft TLS Session Resumption bug

Initial Problem Report

Several months ago we started hearing occasional reports from .NET developers that they were having trouble maintaining HTTPS sessions with one of our customer’s websites. Establishing connections worked just fine but they would periodically get disconnected, resulting in an exception that crashed their application. Around the same time, we also started hearing reports that two other Microsoft products—Internet Explorer and its heir-apparent, Edge—were also having trouble with our edge.

Just a few weeks prior, we had updated our handling of TLS session tickets to be more performant and more secure. We suspected these improvements were the trigger and focused our investigation there. What we learned was that the problem ran much deeper than .NET or IE. It went all the way down to the SChannel security package, which provides TLS functionality for a vast array of Microsoft applications.

TLS Session Tickets

Before diving into the story further, however, it’s helpful to understand exactly what TLS session tickets are, how they’re beneficial to HTTPS, and what optimizations CloudFlare does to use them at scale. (If you’d like to skip over the primer and jump right to the punchline, go ahead and click here.)

Overview

First introduced in Continue reading

OSPF LSA Types

OSPF LSA (link state advertisements) are used to create a logical network topology. But Why we have 11 different LSAs ? What are their purposes ? Most important questions many time is not asked by the engineers thus you can’t find many places on the Internet which provides these answers. The reason of having 11 […]

The post OSPF LSA Types appeared first on Orhanergun.

SD-WAN: What it is and why you’ll use it one day

Managing the Wide Area Network (WAN) for Redmond Inc., a supplier of industrial and commercial products – from salt that’s used to protect winter roadways to organic dairy products and health items – is an easier job today for the company’s technical project manager Aaron Gabrielson than it was a year ago.Redmond manages a phone system, point of sale and fax centrally out of headquarters in Heber City, Utah, which means each of Redmond’s 10 branch sites across the Midwest need a reliable connection back to headquarters in Utah. That’s easier for some sites, like those in Salt Lake City, than others, such as rural areas where there may only be a handful of workers on a farm.To read this article in full or to leave a comment, please click here

Android root malware widespread in third-party app stores

Four third-party app stores for Android have apps with a malicious component that seeks root access to devices, according to Trend Micro. The security company found 1,163 Android application packages containing the malware, which it calls ANDROIDOS_ LIBSKIN.A, wrote Jordan Pan, a mobile threats analyst with Trend. The malware obtains root access to the phone, the highest level of access and privilege. The apps containing the component were downloaded across 169 countries between Jan. 29 and Feb. 1 from marketplaces called Aptoide, Mobogenie, mobile9 and 9apps.To read this article in full or to leave a comment, please click here

So, You Want To Be A Manager

And so it was as a young man that I aspired to be a manager. Management looked like control to me. After all, I thought that as I acquired technical expertise in operating systems, security, and networking, I should be the one holding the reins. That’s logical, perhaps. But it’s naive.

Bill filed in Congress would ban encryption backdoors

Four Congressmen are proposing that states be forbidden to ask manufacturers to install encryption backdoors on their products outfitted with the technology. U.S. Rep. Ted Lieu The four filed a short bill this week that would deny states or parts of states from seeking alterations to products for the purpose of enabling surveillance of the user. It would also block them from seeking the ability to decrypt information that is otherwise unintelligible. The representatives filing the bill are Rep. Ted Lieu (D-Calif.), Rep. Blake Farenthold (R-Texas), Suzan DelBene (D-Wash.) and Mike Bishop (R-Mich.).To read this article in full or to leave a comment, please click here

U.S. intelligence chief touts IoT as a spying opportunity

In a brief aside during a Senate testimony on overall national security this week, U.S. director of national intelligence James Clapper justified the privacy and security advocates who have warned of the implications of the Internet of Things (IoT) since before it was a buzzword."In the future, intelligence services might use the [Internet of Things] for identification, surveillance, monitoring, location tracking, and targeting for recruitment, or to gain access to networks or user credentials," Clapper said, according to The Guardian.To read this article in full or to leave a comment, please click here

Don’t touch the malware at this museum

Malware moments you wish to forgetImage by Jelene Morris (modified)Jason Scott, archivist and software curator for the Internet Archive, and Mikko Hypponen, chief research officer of F-Secure, have brought together this group of malware to mark some of the early viruses. Here are only a few, with another batch to be displayed soon.To read this article in full or to leave a comment, please click here

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