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Following in the Footsteps of Calculators: Qalculate

Reading time7 min
Views1.4K

Previously we did code reviews of large mathematical packages, for example, Scilab and Octave, whereby calculators remained aloof as small utilities, in which it is difficult to make errors due to their small codebase. We were wrong that we haven't paid attention to them. The case with posting the source code of the Windows calculator showed that actually everyone was interested in discussing types of errors hiding in it. Moreover, the number of errors there was more than enough to write an article about that. My colleagues and I, we decided to explore the code of a number of popular calculators, and it turned out that the code of the Windows calculator was not that bad (spoiler).
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How Protonmail is getting censored by FSB in Russia

Reading time10 min
Views8.8K

A completely routine tech support ticket has uncovered unexpected bans of IP addresses of Protonmail — a very useful service for people valuing their Internet freedoms — in several regions of Russia. I seriously didn’t want to sensationalize the headline, but the story is so strange and inexplicable I couldn’t resist.


TL;DR


Disclaimer: the situation is still developing. There might not be anything malicious, but most likely there is. I will update the post once new information comes through.


MTS and Rostelecom — two of the biggest Russian ISPs — started to block traffic to SMTP servers of the encrypted email service Protonmail according to an FSB request, with no regard for the official government registry of restricted websites. It seems like it’s been happening for a while, but no one paid special attention to it. Until now.


All involved parties have received relevant requests for information which they’re obligated to reply.


UPD: MTS has provided a scan of the FSB letter, which is the basis for restricting the access. Justification: the ongoing Universiade in Krasnoyarsk and “phone terrorism”. It’s supposed to prevent ProtonMail emails from going to emergency addresses of security services and schools.


UPD: Protonmail was surprised by “these strange Russians” and their methods for battling fraud abuse, as well as suggested a more effective way to do it — via abuse mailbox.


UPD: FSB’s justification doesn’t appear to be true: the bans broke ProtonMail’s incoming mail, rather than outgoing.


UPD: Protonmail shrugged and changed the IP addresses of their MXs taking them out of the blocking after that particular FSB letter. What will happen next is open ended question.


UPD: Apparently, such letter was not the only one and there is still a set of IP addresses of VOIP-services which are blocked without appropriate records in the official registry of restricted websites.

Another way to write cross-platform apps: Neutralinojs internals and comparison with Electron and NW.js

Reading time5 min
Views9.1K


I am Shalitha Suranga from Sri Lanka. I started Neutralinojs project with other two members as our research project at university.


Cross-platform application development is extremely useful among software development organizations because a large end-user audience can be targeted. Earlier there were several approaches, such as writing multiple codebases per each platform, writing a single codebase using conditionals for platform selection, or using a programming language which has a cross-platform virtual machine at run-time. There were drawbacks of each like complexity of design, limited low-level accessibility and slow learning rate. Cross-platform application development with web technologies came [1] after. Electron and NW.js are most popular frameworks which allow developers to make cross-platform applications using Javascript. Basically, these popular frameworks combine embedded chromium browser and node run-time [2], [3].


These frameworks are being used to create numerous cross-platform applications. Whereas the community pointed out several unseen drawbacks of these frameworks. Large bundled application size, high memory consumption and long development workflow are the key things which were criticized through internet forums and websites [4], [5], [6], [7], [8]. Table 1.1 shows the advantages and disadvantages of Electron/NW.js.


Table 1.1: Advantages and Disadvantages of Electron/NW,js


Advantages of Electron and NW.js Disadvantages of Electron and NW.js
Development is very easy since Javascript is used Application bundle is considered as bloatware (High disk space usage)
Access native functions via node runtimeSingle codebase for all supported platforms Linux, Windows and macOS High memory consumption and slowness
Many Node modules need to be installed
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Functional components with React Hooks. Why it's better?

Reading time5 min
Views24K

When React.js 16.8 was released we got the opportunity to use React Hooks. Hooks make us able to write fully-functional components using functions. We can use all React.js features and do in in more convenient way.


A lot of people don't agree with Hooks conception. In this article I'd like to tell about some important advantages React Hooks give you and why we need to write with Hooks.


I will not talk about how to use hooks. It is not very important for the examples. If you want to read something on this topic, you can use official documentation. Also, if this topic will be interesting for you, I will write more about Hooks.

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Generating multi-brand multi-platform icons with Sketch and a Node.js script — Part #2

Reading time16 min
Views1.6K


This is the second part of a post about the creation of a pipeline that can take a Sketch file and export all the icons included in the file, in different formats, for different platforms, with the possibility of AB testing each icon.

You can read the first part of the post here.



The Sketch files, with all the icons collected, styled and properly named, were ready. Now it was time to start writing the code.

Suffice to say, the process was very much a trial and error: after the important initial code core, developed by my team lead Nikhil Verma (who set the script foundations), I went through an incremental process that required at least three phases of refactoring and quite a few revisions. For this reason, I won’t go into too much detail on how the script was developed, but rather focus on how the script works today, in its final shape.
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Counting Bugs in Windows Calculator

Reading time11 min
Views42K

A few days ago, Microsoft made the source code of their Windows Calculator publicly available. Calculator is an application that has traditionally shipped with every Windows version. A number of Microsoft projects went open-source over the recent years, but this time the news was covered even by non-IT media on the very first day. Well, it's a popular yet tiny program in C++. Despite its size, we still managed to find a number of suspicious fragments in its code using the PVS-Studio static analyzer.
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Writing a wasm loader for Ghidra. Part 1: Problem statement and setting up environment

Reading time7 min
Views12K

This week, NSA (National Security Agency) all of a sudden made a gift to humanity, opening sources of their software reverse engineering framework. Community of the reverse engineers and security experts with great enthusiasm started to explore the new toy. According to the feedback, it’s really amazing tool, able to compete with existing solutions, such as IDA Pro, R2 and JEB. The tool is called Ghidra and professional resources are full of impressions from researchers. Actually, they had a good reason: not every day government organizations provide access to their internal tools. Myself as a professional reverse engineer and malware analyst couldn’t pass by as well. I decided to spend a weekend or two and get a first impression of the tool. I had played a bit with disassembly and decided to check extensibility of the tool. In this series of articles, I'll explain the development of Ghidra add-on, which loads custom format, used to solve CTF task. As it’s a large framework and I've chosen quite complicated task, I’ll break the article into several parts.

By the end of this part I hope to setup development environment and build minimal module, which will be able to recognize format of the WebAssembly file and will suggest the right disassembler to process it.
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Navigation in Multi-Module Projects

Reading time10 min
Views10K


Navigation in developing Android apps is quite important and you should think twice what library suits (or your own solution) most and how it will be convenient to use when the app becomes bigger. Also, it might be good to think about how easy it will be to change your implementation to another one.
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Crystal Blockchain Analytics: Investigating the Hacks and Theft Cases

Reading time8 min
Views3K
In this report, Bitfury shares analysis completed by its Crystal Blockchain Analytics engineering team on the movement of bitcoin from the Zaif exchange, Bithumb exchange and Electrum wallets.

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Angular vs React: Complete Library with a Framework

Reading time6 min
Views1.1K
image

Google and Facebook are the computerized behemoths who dependably contend. Their answers for designers Angular and React appear matches as well. Demand helps look at both. The article was initially posted here


Toward the start of its advancement, SPA web stages did not have an adaptable however basic framework for making the ventures that could revise and, now and again, supplant both portable and work area applications. Around then, a client whose issue was very basic needed to discover an application equipped for tackling the issue. Over the span of time, the advancements continued pushing ahead making web administrations gain ubiquity since the last had no should be introduced. What was required is simply to visit a site for getting to some administration. Already, such errands could be tackled through sites written in either ActionScript or Java. Nonetheless, those frameworks required to introduce either Flash or Java being in the meantime a long way from the speed expected by the clients.@Angular


By then, JavaScript advanced adequately to desert its adversaries because of a fast, improvement straightforwardness, and ceaseless help of the programs' engineers. The period of JavaScript began inciting such definition as SPA (Single Page Application) which gave another way to deal with the advancement of web stages. Not at all like its precursor MPA (Multi-Page Application), SPA permitted a web administration to work a lot quicker just as to give it an increasingly refined usefulness fit for changing progressively as per clients' needs. The greatest disadvantage was in unadulterated JavaScript which couldn't give a quick improvement when even a crude SPA web administration required a ton of time to be made. That is the reason Google chosen to help the methodology with a system that could enable different organizations to create muddled web administrations without investing a lot of energy for it.

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How to Discover MongoDB and Elasticsearch Open Databases

Reading time3 min
Views17K

Some time ago among security researchers, it was very “fashionable” to find improperly configured AWS cloud storages with various kinds of confidential information. At that time, I even published a small note about how Amazon S3 open cloud storage is discovered.


However, time passes and the focus in research has shifted to the search for unsecured and exposed public domain databases. More than half of the known cases of large data leaks over the past year are leaks from open databases.



Today we will try to figure out how such databases are discovered by security researchers...

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My and my girlfriend’s first video game. Development with Unity. Part 1

Reading time7 min
Views5.5K
If not to take into account releases for Android and a dozen of abandoned projects just before they were ready, then yes, it is our first game appropriate for more than one platform. How did it all start? Very simply. We worked on another project, let’s call it “project A”, and we’d been working on it for a long time when we decided to make a game during a couple of months and use it to train our marketing skills, and then immediately release our “project A” when we would be more experienced in the promotion of games. But the plan failed and “project A” was kept untouched for the whole year. But this story isn’t about “project A”, it’s about a logical game called «Cubicity: Slide puzzle».


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VShard — horizontal scaling in Tarantool

Reading time14 min
Views2.6K


Hi, my name is Vladislav, and I am a member of the Tarantool development team. Tarantool is a DBMS and an application server all in one. Today I am going to tell the story of how we implemented horizontal scaling in Tarantool by means of the VShard module.

Some basic knowledge first.

There are two types of scaling: horizontal and vertical. And there are two types of horizontal scaling: replication and sharding. Replication ensures computational scaling whereas sharding is used for data scaling.

Sharding is also subdivided into two types: range-based sharding and hash-based sharding.

Range-based sharding implies that some shard key is computed for each cluster record. The shard keys are projected onto a straight line that is separated into ranges and allocated to different physical nodes.

Hash-based sharding is less complicated: a hash function is calculated for each record in a cluster; records with the same hash function are allocated to the same physical node.

I will focus on horizontal scaling using hash-based sharding.
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Levelord, an Ordinary Moscow Resident: Interview with the Creator of Duke Nukem

Reading time20 min
Views6.5K
RUVDS together with Habr.com continues the series of interviews with interesting people in computer field. Previously we met Boris Yangel, who heads AI development of Yandex’s Alice voice assistant.

Today we bring you an interview with Richard (Levelord) Gray — level designer of such legendary games as Duke Nukem, American McGee Alice, Heavy Metal F.A.K.K.2, SiN, and Serious Sam. And he is the one who coined the famous phrase «You are not supposed to be here». Richard was born and spent most of his life in USA, but several years ago he moved to Moscow to his russian wife and daughter.

These who speak to Richard are Nick Zemlyanskiy, editor of Habr.com, and Nikita Tsaplin, co-founder and managing partner of RUVDS company.


→ Text and video in Russian

Digital Forensics Tips&Tricks: How to Find Active VPN Connection in the Memory Dump

Reading time2 min
Views9K
Sometimes you can meet a case when a cyber-attacker uses VPN to establish a reliable channel between C2 server and infected IT-infrastructure. And, as Threat Intelligence experts say, attackers often use native Windows VPN connection tools and Windows .pbk (phonebook) files. Lets find out how we can detect it using a memory dump.

What is .pbk file and how does it look inside? It's just a text file with a lot of different parameters using when VPN connection is establishing.

image

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Indexes in PostgreSQL — 2

Reading time5 min
Views8.1K

Interface


In the first article, we've mentioned that an access method must provide information about itself. Let's look into the structure of the access method interface.

Properties


All properties of access methods are stored in the «pg_am» table («am» stands for access method). We can also get a list of available methods from this same table:

postgres=# select amname from pg_am;
 amname
--------
 btree
 hash
 gist
 gin
 spgist
 brin
(6 rows)

Although sequential scan can rightfully be referred to access methods, it is not on this list for historical reasons.

In PostgreSQL versions 9.5 and lower, each property was represented with a separate field of the «pg_am» table. Starting with version 9.6, properties are queried with special functions and are separated into several layers:

  • Access method properties — «pg_indexam_has_property»
  • Properties of a specific index — «pg_index_has_property»
  • Properties of individual columns of the index — «pg_index_column_has_property»

The access method layer and index layer are separated with an eye towards the future: as of now, all indexes based on one access method will always have the same properties.
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