Tag Archives: encoding

SecureLogin For Java Web Applications

Post Syndicated from Bozho original https://techblog.bozho.net/securelogin-java-web-applications/

No, there is not a missing whitespace in the title. It’s not about any secure login, it’s about the SecureLogin protocol developed by Egor Homakov, a security consultant, who became famous for committing to master in the Rails project without having permissions.

The SecureLogin protocol is very interesting, as it does not rely on any central party (e.g. OAuth providers like Facebook and Twitter), thus avoiding all the pitfalls of OAuth (which Homakov has often criticized). It is not a password manager either. It is just a client-side software that performs a bit of crypto in order to prove to the server that it is indeed the right user. For that to work, two parts are key:

  • Using a master password to generate a private key. It uses a key-derivation function, which guarantees that the produced private key has sufficient entropy. That way, using the same master password and the same email, you will get the same private key everytime you use the password, and therefore the same public key. And you are the only one who can prove this public key is yours, by signing a message with your private key.
  • Service providers (websites) identify you by your public key by storing it in the database when you register and then looking it up on each subsequent login

The client-side part is performed ideally by a native client – a browser plugin (one is available for Chrome) or a OS-specific application (including mobile ones). That may sound tedious, but it’s actually quick and easy and a one-time event (and is easier than password managers).

I have to admit – I like it, because I’ve been having a similar idea for a while. In my “biometric identification” presentation (where I discuss the pitfalls of using biometrics-only identification schemes), I proposed (slide 23) an identification scheme that uses biometrics (e.g. scanned with your phone) + a password to produce a private key (using a key-derivation function). And the biometric can easily be added to SecureLogin in the future.

It’s not all roses, of course, as one issue isn’t fully resolved yet – revocation. In case someone steals your master password (or you suspect it might be stolen), you may want to change it and notify all service providers of that change so that they can replace your old public key with a new one. That has two implications – first, you may not have a full list of sites that you registered on, and since you may have changed devices, or used multiple devices, there may be websites that never get to know about your password change. There are proposed solutions (points 3 and 4), but they are not intrinsic to the protocol and rely on centralized services. The second issue is – what if the attacker changes your password first? To prevent that, service providers should probably rely on email verification, which is neither part of the protocol, nor is encouraged by it. But you may have to do it anyway, as a safeguard.

Homakov has not only defined a protocol, but also provided implementations of the native clients, so that anyone can start using it. So I decided to add it to a project I’m currently working on (the login page is here). For that I needed a java implementation of the server verification, and since no such implementation existed (only ruby and node.js are provided for now), I implemented it myself. So if you are going to use SecureLogin with a Java web application, you can use that instead of rolling out your own. While implementing it, I hit a few minor issues that may lead to protocol changes, so I guess backward compatibility should also be somehow included in the protocol (through versioning).

So, how does the code look like? On the client side you have a button and a little javascript:

<!-- get the latest sdk.js from the GitHub repo of securelogin
   or include it from https://securelogin.pw/sdk.js -->
<script src="js/securelogin/sdk.js"></script>
<p class="slbutton" id="securelogin">&#9889; SecureLogin</p>
$("#securelogin").click(function() {
	// TODO: consider adding csrf protection as in the demo applications
        // Note - pass as request body, not as param, as the token relies 
        // on url-encoding which some frameworks mess with
	$.post('/app/user/securelogin', sltoken, function(result) {
            if(result == 'ok') {
		 window.location = "/app/";
            } else {
                 $.notify("Login failed, try again later", "error");
  return false;

A single button can be used for both login and signup, or you can have a separate signup form, if it has to include additional details rather than just an email. Since I added SecureLogin in addition to my password-based login, I kept the two forms.

On the server, you simply do the following:

@RequestMapping(value = "/securelogin/register", method = RequestMethod.POST)
public String secureloginRegister(@RequestBody String token, HttpServletResponse response) {
    try {
        SecureLogin login = SecureLogin.verify(request.getSecureLoginToken(), Options.create(websiteRootUrl));
        UserDetails details = userService.getUserDetailsByEmail(login.getEmail());
        if (details == null || !login.getRawPublicKey().equals(details.getSecureLoginPublicKey())) {
            return "failure";
        // sets the proper cookies to the response
        TokenAuthenticationService.addAuthentication(response, login.getEmail(), secure));
        return "ok";
    } catch (SecureLoginVerificationException e) {
        return "failure";

This is spring-mvc, but it can be any web framework. You can also incorporate that into a spring-security flow somehow. I’ve never liked spring-security’s complexity, so I did it manually. Also, instead of strings, you can return proper status codes. Note that I’m doing a lookup by email and only then checking the public key (as if it’s a password). You can do the other way around if you have the proper index on the public key column.

I wouldn’t suggest having a SecureLogin-only system, as the project is still in an early stage and users may not be comfortable with it. But certainly adding it as an option is a good idea.

The post SecureLogin For Java Web Applications appeared first on Bozho's tech blog.

Backblaze’s Upgrade Guide for macOS High Sierra

Post Syndicated from Roderick Bauer original https://www.backblaze.com/blog/macos-high-sierra-upgrade-guide/

High Sierra

Apple introduced macOS 10.13 “High Sierra” at its 2017 Worldwide Developers Conference in June. On Tuesday, we learned we don’t have long to wait — the new OS will be available on September 25. It’s a free upgrade, and millions of Mac users around the world will rush to install it.

We understand. A new OS from Apple is exciting, But please, before you upgrade, we want to remind you to back up your Mac. You want your data to be safe from unexpected problems that could happen in the upgrade. We do, too. To make that easier, Backblaze offers this macOS High Sierra upgrade guide.

Why Upgrade to macOS 10.13 High Sierra?

High Sierra, as the name suggests, is a follow-on to the previous macOS, Sierra. Its major focus is on improving the base OS with significant improvements that will support new capabilities in the future in the file system, video, graphics, and virtual/augmented reality.

But don’t despair; there also are outward improvements that will be readily apparent to everyone when they boot the OS for the first time. We’ll cover both the inner and outer improvements coming in this new OS.

Under the Hood of High Sierra

APFS (Apple File System)

Apple has been rolling out its first file system upgrade for a while now. It’s already in iOS: now High Sierra brings APFS to the Mac. Apple touts APFS as a new file system optimized for Flash/SSD storage and featuring strong encryption, better and faster file handling, safer copying and moving of files, and other improved file system fundamentals.

We went into detail about the enhancements and improvements that APFS has over the previous file system, HFS+, in an earlier post. Many of these improvements, including enhanced performance, security and reliability of data, will provide immediate benefits to users, while others provide a foundation for future storage innovations and will require work by Apple and third parties to support in their products and services.

Most of us won’t notice these improvements, but we’ll benefit from better, faster, and safer file handling, which I think all of us can appreciate.


High Sierra includes High Efficiency Video Encoding (HEVC, aka H.265), which preserves better detail and color while also introducing improved compression over H.264 (MPEG-4 AVC). Even existing Macs will benefit from the HEVC software encoding in High Sierra, but newer Mac models include HEVC hardware acceleration for even better performance.

MacBook Pro

Metal 2

macOS High Sierra introduces Metal 2, the next-generation of Apple’s Metal graphics API that was launched three years ago. Apple claims that Metal 2 provides up to 10x better performance in key areas. It provides near-direct access to the graphics processor (GPU), enabling the GPU to take control over key aspects of the rendering pipeline. Metal 2 will enhance the Mac’s capability for machine learning, and is the technology driving the new virtual reality platform on Macs.

audio video editor screenshot

Virtual Reality

We’re about to see an explosion of virtual reality experiences on both the Mac and iOS thanks to High Sierra and iOS 11. Content creators will be able to use apps like Final Cut Pro X, Epic Unreal 4 Editor, and Unity Editor to create fully immersive worlds that will revolutionize entertainment and education and have many professional uses, as well.

Users will want the new iMac with Retina 5K display or the upcoming iMac Pro to enjoy them, or any supported Mac paired with the latest external GPU and VR headset.

iMac and HTC virtual reality player

Outward Improvements


Siri logo

Expect a more nature voice from Siri in High Sierra. She or he will be less robotic, with greater expression and use of intonation in speech. Siri will also learn more about your preferences in things like music, helping you choose music that fits your taste and putting together playlists expressly for you. Expect Siri to be able to answer your questions about music-related trivia, as well.

Siri:  what does “scaramouche” refer to in the song Bohemian Rhapsody?


HD MacBook Pro screenshot

Photos has been redesigned with a new layout and new tools. A redesigned Edit view includes new tools for fine-tuning color and contrast and making adjustments within a defined color range. Some fun elements for creating special effects and memories also have been added. Photos now works with external apps such as Photoshop and Pixelmator. Compatibility with third-party extension adds printing and publishing services to help get your photos out into the world.


Safari logo

Apple claims that Safari in High Sierra is the world’s fastest desktop browser, outperforming Chrome and other browsers in a range of benchmark tests. They’ve also added autoplay blocking for those pesky videos that play without your permission and tracking blocking to help protect your privacy.

Can My Mac Run macOS High Sierra 10.13?

All Macs introduced in mid 2010 or later are compatible. MacBook and iMac computers introduced in late 2009 are also compatible. You’ll need OS X 10.7.5 “Lion” or later installed, along with at least 2 GB RAM and 8.8 GB of available storage to manage the upgrade.
Some features of High Sierra require an internet connection or an Apple ID. You can check to see if your Mac is compatible with High Sierra on Apple’s website.

Conquering High Sierra — What Do I Do Before I Upgrade?

Back Up That Mac!

It’s always smart to back up before you upgrade the operating system or make any other crucial changes to your computer. Upgrading your OS is a major change to your computer, and if anything goes wrong…well, you don’t want that to happen.

iMac backup screenshot

We recommend the 3-2-1 Backup Strategy to make sure your data is safe. What does that mean? Have three copies of your data. There’s the “live” version on your Mac, a local backup (Time Machine, another copy on a local drive or other computer), and an offsite backup like Backblaze. No matter what happens to your computer, you’ll have a way to restore the files if anything goes wrong. Need help understanding how to back up your Mac? We have you covered with a handy Mac backup guide.

Check for App and Driver Updates

This is when it helps to do your homework. Check with app developers or device manufacturers to find if their apps and devices have updates to work with High Sierra. Visit their websites or use the Check for Updates feature built into most apps (often found in the File or Help menus).

If you’ve downloaded apps through the Mac App Store, make sure to open them and click on the Updates button to download the latest updates.

Updating can be hit or miss when you’ve installed apps that didn’t come from the Mac App Store. To make it easier, visit the MacUpdate website. MacUpdate tracks changes to thousands of Mac apps.

Will Backblaze work with macOS High Sierra?

Yes. We’ve taken care to ensure that Backblaze works with High Sierra. We’ve already enhanced our Macintosh client to report the space available on an APFS container and we plan to add additional support for APFS capabilities that enhance Backblaze’s capabilities in the future.

Of course, we’ll watch Apple’s release carefully for any last minute surprises. We’ll officially offer support for High Sierra once we’ve had a chance to thoroughly test the release version.

Set Aside Time for the Upgrade

Depending on the speed of your Internet connection and your computer, upgrading to High Sierra will take some time. You’ll be able to use your Mac straightaway after answering a few questions at the end of the upgrade process.

If you’re going to install High Sierra on multiple Macs, a time-and-bandwidth-saving tip came from a Backblaze customer who suggested copying the installer from your Mac’s Applications folder to a USB Flash drive (or an external drive) before you run it. The installer routinely deletes itself once the upgrade process is completed, but if you grab it before that happens you can use it on other computers.

Where Do I get High Sierra?

Apple says that High Sierra will be available on September 25. Like other Mac operating system releases, Apple offers macOS 10.13 High Sierra for download from the Mac App Store, which is included on the Mac. As long as your Mac is supported and running OS X 10.7.5 “Lion” (released in 2012) or later, you can download and run the installer. It’s free. Thank you, Apple.

Better to be Safe than Sorry

Back up your Mac before doing anything to it, and make Backblaze part of your 3-2-1 backup strategy. That way your data is secure. Even if you have to roll back after an upgrade, or if you run into other problems, your data will be safe and sound in your backup.

Tell us How it Went

Are you getting ready to install High Sierra? Still have questions? Let us know in the comments. Tell us how your update went and what you like about the new release of macOS.

And While You’re Waiting for High Sierra…

While you’re waiting for Apple to release High Sierra on September 25, you might want to check out these other posts about using your Mac and Backblaze.

The post Backblaze’s Upgrade Guide for macOS High Sierra appeared first on Backblaze Blog | Cloud Storage & Cloud Backup.

Disabling Intel Hyper-Threading Technology on Amazon EC2 Windows Instances

Post Syndicated from Brian Beach original https://aws.amazon.com/blogs/compute/disabling-intel-hyper-threading-technology-on-amazon-ec2-windows-instances/

In a prior post, Disabling Intel Hyper-Threading on Amazon Linux, I investigated how the Linux kernel enumerates CPUs. I also discussed the options to disable Intel Hyper-Threading (HT Technology) in Amazon Linux running on Amazon EC2.

In this post, I do the same for Microsoft Windows Server 2016 running on EC2 instances. I begin with a quick review of HT Technology and the reasons you might want to disable it. I also recommend that you take a moment to review the prior post for a more thorough foundation.

HT Technology

HT Technology makes a single physical processor appear as multiple logical processors. Each core in an Intel Xeon processor has two threads of execution. Most of the time, these threads can progress independently; one thread executing while the other is waiting on a relatively slow operation (for example, reading from memory) to occur. However, the two threads do share resources and occasionally one thread is forced to wait while the other is executing.

There a few unique situations where disabling HT Technology can improve performance. One example is high performance computing (HPC) workloads that rely heavily on floating point operations. In these rare cases, it can be advantageous to disable HT Technology. However, these cases are rare, and for the overwhelming majority of workloads you should leave it enabled. I recommend that you test with and without HT Technology enabled, and only disable threads if you are sure it will improve performance.

Exploring HT Technology on Microsoft Windows

Here’s how Microsoft Windows enumerates CPUs. As before, I am running these examples on an m4.2xlarge. I also chose to run Windows Server 2016, but you can walk through these exercises on any version of Windows. Remember that the m4.2xlarge has eight vCPUs, and each vCPU is a thread of an Intel Xeon core. Therefore, the m4.2xlarge has four cores, each of which run two threads, resulting in eight vCPUs.

Windows does not have a built-in utility to examine CPU configuration, but you can download the Sysinternals coreinfo utility from Microsoft’s website. This utility provides useful information about the system CPU and memory topology. For this walkthrough, you enumerate the individual CPUs, which you can do by running coreinfo -c. For example:

C:\Users\Administrator >coreinfo -c

Coreinfo v3.31 - Dump information on system CPU and memory topology
Copyright (C) 2008-2014 Mark Russinovich
Sysinternals - www.sysinternals.com

Logical to Physical Processor Map:
**------ Physical Processor 0 (Hyperthreaded)
--**---- Physical Processor 1 (Hyperthreaded)
----**-- Physical Processor 2 (Hyperthreaded)
------** Physical Processor 3 (Hyperthreaded)

As you can see from the screenshot, the coreinfo utility displays a table where each row is a physical core and each column is a logical CPU. In other words, the two asterisks on the first line indicate that CPU 0 and CPU 1 are the two threads in the first physical core. Therefore, my m4.2xlarge has for four physical processors and each processor has two threads resulting in eight total CPUs, just as expected.

It is interesting to note that Windows Server 2016 enumerates CPUs in a different order than Linux. Remember from the prior post that Linux enumerated the first thread in each core, followed by the second thread in each core. You can see from the output earlier that Windows Server 2016, enumerates both threads in the first core, then both threads in the second core, and so on. The diagram below shows the relationship of CPUs to cores and threads in both operating systems.

In the Linux post, I disabled CPUs 4–6, leaving one thread per core, and effectively disabling HT Technology. You can see from the diagram that you must disable the odd-numbered threads (that is, 1, 3, 5, and 7) to achieve the same result in Windows. Here’s how to do that.

Disabling HT Technology on Microsoft Windows

In Linux, you can globally disable CPUs dynamically. In Windows, there is no direct equivalent that I could find, but there are a few alternatives.

First, you can disable CPUs using the msconfig.exe tool. If you choose Boot, Advanced Options, you have the option to set the number of processors. In the example below, I limit my m4.2xlarge to four CPUs. Restart for this change to take effect.

Unfortunately, Windows does not disable hyperthreaded CPUs first and then real cores, as Linux does. As you can see in the following output, coreinfo reports that my c4.2xlarge has two real cores and four hyperthreads, after rebooting. Msconfig.exe is useful for disabling cores, but it does not allow you to disable HT Technology.

Note: If you have been following along, you can re-enable all your CPUs by unselecting the Number of processors check box and rebooting your system.


C:\Users\Administrator >coreinfo -c

Coreinfo v3.31 - Dump information on system CPU and memory topology
Copyright (C) 2008-2014 Mark Russinovich
Sysinternals - www.sysinternals.com

Logical to Physical Processor Map:
**-- Physical Processor 0 (Hyperthreaded)
--** Physical Processor 1 (Hyperthreaded)

While you cannot disable HT Technology systemwide, Windows does allow you to associate a particular process with one or more CPUs. Microsoft calls this, “processor affinity”. To see an example, use the following steps.

  1. Launch an instance of Notepad.
  2. Open Windows Task Manager and choose Processes.
  3. Open the context (right click) menu on notepad.exe and choose Set Affinity….

This brings up the Processor Affinity dialog box.

As you can see, all the CPUs are allowed to run this instance of notepad.exe. You can uncheck a few CPUs to exclude them. Windows is smart enough to allow any scheduled operations to continue to completion on disabled CPUs. It then saves its state at the next scheduling event, and resumes those operations on another CPU. To ensure that only one thread in each core is able to run a process, you uncheck every other core. This effectively disables HT Technology for this process. For example:

Of course, this can be tedious when you have a large number of cores. Remember that the x1.32xlarge has 128 CPUs. Luckily, you can set the affinity of a running process from PowerShell using the Get-Process cmdlet. For example:

PS C:\&gt; (Get-Process -Name 'notepad').ProcessorAffinity = 0x55;

The ProcessorAffinity attribute takes a bitmask in hexadecimal format. 0x55 in hex is equivalent to 01010101 in binary. Think of the binary encoding as 1=enabled and 0=disabled. This is slightly confusing, but we work left to right so that CPU 0 is the rightmost bit and CPU 7 is the leftmost bit. Therefore, 01010101 means that the first thread in each CPU is enabled just as it was in the diagram earlier.

The calculator built into Windows includes a “programmer view” that helps you convert from hexadecimal to binary. In addition, the ProcessorAffinity attribute is a 64-bit number. Therefore, you can only configure the processor affinity on systems up to 64 CPUs. At the moment, only the x1.32xlarge has more than 64 vCPUs.

In the preceding examples, you changed the processor affinity of a running process. Sometimes, you want to start a process with the affinity already configured. You can do this using the start command. The start command includes an affinity flag that takes a hexadecimal number like the PowerShell example earlier.

C:\Users\Administrator&gt;start /affinity 55 notepad.exe

It is interesting to note that a child process inherits the affinity from its parent. For example, the following commands create a batch file that launches Notepad, and starts the batch file with the affinity set. If you examine the instance of Notepad launched by the batch file, you see that the affinity has been applied to as well.

C:\Users\Administrator&gt;echo notepad.exe > test.bat
C:\Users\Administrator&gt;start /affinity 55 test.bat

This means that you can set the affinity of your task scheduler and any tasks that the scheduler starts inherits the affinity. So, you can disable every other thread when you launch the scheduler and effectively disable HT Technology for all of the tasks as well. Be sure to test this point, however, as some schedulers override the normal inheritance behavior and explicitly set processor affinity when starting a child process.


While the Windows operating system does not allow you to disable logical CPUs, you can set processor affinity on individual processes. You also learned that Windows Server 2016 enumerates CPUs in a different order than Linux. Therefore, you can effectively disable HT Technology by restricting a process to every other CPU. Finally, you learned how to set affinity of both new and running processes using Task Manager, PowerShell, and the start command.

Note: this technical approach has nothing to do with control over software licensing, or licensing rights, which are sometimes linked to the number of “CPUs” or “cores.” For licensing purposes, those are legal terms, not technical terms. This post did not cover anything about software licensing or licensing rights.

If you have questions or suggestions, please comment below.

From Data Lake to Data Warehouse: Enhancing Customer 360 with Amazon Redshift Spectrum

Post Syndicated from Dylan Tong original https://aws.amazon.com/blogs/big-data/from-data-lake-to-data-warehouse-enhancing-customer-360-with-amazon-redshift-spectrum/

Achieving a 360o-view of your customer has become increasingly challenging as companies embrace omni-channel strategies, engaging customers across websites, mobile, call centers, social media, physical sites, and beyond. The promise of a web where online and physical worlds blend makes understanding your customers more challenging, but also more important. Businesses that are successful in this medium have a significant competitive advantage.

The big data challenge requires the management of data at high velocity and volume. Many customers have identified Amazon S3 as a great data lake solution that removes the complexities of managing a highly durable, fault tolerant data lake infrastructure at scale and economically.

AWS data services substantially lessen the heavy lifting of adopting technologies, allowing you to spend more time on what matters most—gaining a better understanding of customers to elevate your business. In this post, I show how a recent Amazon Redshift innovation, Redshift Spectrum, can enhance a customer 360 initiative.

Customer 360 solution

A successful customer 360 view benefits from using a variety of technologies to deliver different forms of insights. These could range from real-time analysis of streaming data from wearable devices and mobile interactions to historical analysis that requires interactive, on demand queries on billions of transactions. In some cases, insights can only be inferred through AI via deep learning. Finally, the value of your customer data and insights can’t be fully realized until it is operationalized at scale—readily accessible by fleets of applications. Companies are leveraging AWS for the breadth of services that cover these domains, to drive their data strategy.

A number of AWS customers stream data from various sources into a S3 data lake through Amazon Kinesis. They use Kinesis and technologies in the Hadoop ecosystem like Spark running on Amazon EMR to enrich this data. High-value data is loaded into an Amazon Redshift data warehouse, which allows users to analyze and interact with data through a choice of client tools. Redshift Spectrum expands on this analytics platform by enabling Amazon Redshift to blend and analyze data beyond the data warehouse and across a data lake.

The following diagram illustrates the workflow for such a solution.

This solution delivers value by:

  • Reducing complexity and time to value to deeper insights. For instance, an existing data model in Amazon Redshift may provide insights across dimensions such as customer, geography, time, and product on metrics from sales and financial systems. Down the road, you may gain access to streaming data sources like customer-care call logs and website activity that you want to blend in with the sales data on the same dimensions to understand how web and call center experiences maybe correlated with sales performance. Redshift Spectrum can join these dimensions in Amazon Redshift with data in S3 to allow you to quickly gain new insights, and avoid the slow and more expensive alternative of fully integrating these sources with your data warehouse.
  • Providing an additional avenue for optimizing costs and performance. In cases like call logs and clickstream data where volumes could be many TBs to PBs, storing the data exclusively in S3 yields significant cost savings. Interactive analysis on massive datasets may now be economically viable in cases where data was previously analyzed periodically through static reports generated by inexpensive batch processes. In some cases, you can improve the user experience while simultaneously lowering costs. Spectrum is powered by a large-scale infrastructure external to your Amazon Redshift cluster, and excels at scanning and aggregating large volumes of data. For instance, your analysts maybe performing data discovery on customer interactions across millions of consumers over years of data across various channels. On this large dataset, certain queries could be slow if you didn’t have a large Amazon Redshift cluster. Alternatively, you could use Redshift Spectrum to achieve a better user experience with a smaller cluster.

Proof of concept walkthrough

To make evaluation easier for you, I’ve conducted a Redshift Spectrum proof-of-concept (PoC) for the customer 360 use case. For those who want to replicate the PoC, the instructions, AWS CloudFormation templates, and public data sets are available in the GitHub repository.

The remainder of this post is a journey through the project, observing best practices in action, and learning how you can achieve business value. The walkthrough involves:

  • An analysis of performance data from the PoC environment involving queries that demonstrate blending and analysis of data across Amazon Redshift and S3. Observe that great results are achievable at scale.
  • Guidance by example on query tuning, design, and data preparation to illustrate the optimization process. This includes tuning a query that combines clickstream data in S3 with customer and time dimensions in Amazon Redshift, and aggregates ~1.9 B out of 3.7 B+ records in under 10 seconds with a small cluster!
  • Guidance and measurements to help assess deciding between two options: accessing and analyzing data exclusively in Amazon Redshift, or using Redshift Spectrum to access data left in S3.

Stream ingestion and enrichment

The focus of this post isn’t stream ingestion and enrichment on Kinesis and EMR, but be mindful of performance best practices on S3 to ensure good streaming and query performance:

  • Use random object keys: The data files provided for this project are prefixed with SHA-256 hashes to prevent hot partitions. This is important to ensure that optimal request rates to support PUT requests from the incoming stream in addition to certain queries from large Amazon Redshift clusters that could send a large number of parallel GET requests.
  • Micro-batch your data stream: S3 isn’t optimized for small random write workloads. Your datasets should be micro-batched into large files. For instance, the “parquet-1” dataset provided batches >7 million records per file. The optimal file size for Redshift Spectrum is usually in the 100 MB to 1 GB range.

If you have an edge case that may pose scalability challenges, AWS would love to hear about it. For further guidance, talk to your solutions architect.


The project consists of the following environment:

  • Amazon Redshift cluster: 4 X dc1.large
  • Data:
    • Time and customer dimension tables are stored on all Amazon Redshift nodes (ALL distribution style):
      • The data originates from the DWDATE and CUSTOMER tables in the Star Schema Benchmark
      • The customer table contains attributes for 3 million customers.
      • The time data is at the day-level granularity, and spans 7 years, from the start of 1992 to the end of 1998.
    • The clickstream data is stored in an S3 bucket, and serves as a fact table.
      • Various copies of this dataset in CSV and Parquet format have been provided, for reasons to be discussed later.
      • The data is a modified version of the uservisits dataset from AMPLab’s Big Data Benchmark, which was generated by Intel’s Hadoop benchmark tools.
      • Changes were minimal, so that existing test harnesses for this test can be adapted:
        • Increased the 751,754,869-row dataset 5X to 3,758,774,345 rows.
        • Added surrogate keys to support joins with customer and time dimensions. These keys were distributed evenly across the entire dataset to represents user visits from six customers over seven years.
        • Values for the visitDate column were replaced to align with the 7-year timeframe, and the added time surrogate key.

Queries across the data lake and data warehouse 

Imagine a scenario where a business analyst plans to analyze clickstream metrics like ad revenue over time and by customer, market segment and more. The example below is a query that achieves this effect: 

The query part highlighted in red retrieves clickstream data in S3, and joins the data with the time and customer dimension tables in Amazon Redshift through the part highlighted in blue. The query returns the total ad revenue for three customers over the last three months, along with info on their respective market segment.

Unfortunately, this query takes around three minutes to run, and doesn’t enable the interactive experience that you want. However, there’s a number of performance optimizations that you can implement to achieve the desired performance.

Performance analysis

Two key utilities provide visibility into Redshift Spectrum:

    Provides the query execution plan, which includes info around what processing is pushed down to Redshift Spectrum. Steps in the plan that include the prefix S3 are executed on Redshift Spectrum. For instance, the plan for the previous query has the step “S3 Seq Scan clickstream.uservisits_csv10”, indicating that Redshift Spectrum performs a scan on S3 as part of the query execution.
    Statistics for Redshift Spectrum queries are stored in this table. While the execution plan presents cost estimates, this table stores actual statistics for past query runs.

You can get the statistics of your last query by inspecting the SVL_S3QUERY_SUMMARY table with the condition (query = pg_last_query_id()). Inspecting the previous query reveals that the entire dataset of nearly 3.8 billion rows was scanned to retrieve less than 66.3 million rows. Improving scan selectivity in your query could yield substantial performance improvements.


Partitioning is a key means to improving scan efficiency. In your environment, the data and tables have already been organized, and configured to support partitions. For more information, see the PoC project setup instructions. The clickstream table was defined as:

CREATE EXTERNAL TABLE clickstream.uservisits_csv10
PARTITIONED BY(customer int4, visitYearMonth int4)

The entire 3.8 billion-row dataset is organized as a collection of large files where each file contains data exclusive to a particular customer and month in a year. This allows you to partition your data into logical subsets by customer and year/month. With partitions, the query engine can target a subset of files:

  • Only for specific customers
  • Only data for specific months
  • A combination of specific customers and year/months

You can use partitions in your queries. Instead of joining your customer data on the surrogate customer key (that is, c.c_custkey = uv.custKey), the partition key “customer” should be used instead:

SELECT c.c_name, c.c_mktsegment, t.prettyMonthYear, SUM(uv.adRevenue)
ON c.c_custkey = uv.customer
ORDER BY c.c_name, c.c_mktsegment, uv.yearMonthKey  ASC

This query should run approximately twice as fast as the previous query. If you look at the statistics for this query in SVL_S3QUERY_SUMMARY, you see that only half the dataset was scanned. This is expected because your query is on three out of six customers on an evenly distributed dataset. However, the scan is still inefficient, and you can benefit from using your year/month partition key as well:

SELECT c.c_name, c.c_mktsegment, t.prettyMonthYear, SUM(uv.adRevenue)
ON c.c_custkey = uv.customer
ON uv.visitYearMonth = t.d_yearmonthnum
ORDER BY c.c_name, c.c_mktsegment, uv.visitYearMonth ASC

All joins between the tables are now using partitions. Upon reviewing the statistics for this query, you should observe that Redshift Spectrum scans and returns the exact number of rows, 66,270,117. If you run this query a few times, you should see execution time in the range of 8 seconds, which is a 22.5X improvement on your original query!

Predicate pushdown and storage optimizations 

Previously, I mentioned that Redshift Spectrum performs processing through large-scale infrastructure external to your Amazon Redshift cluster. It is optimized for performing large scans and aggregations on S3. In fact, Redshift Spectrum may even out-perform a medium size Amazon Redshift cluster on these types of workloads with the proper optimizations. There are two important variables to consider for optimizing large scans and aggregations:

  • File size and count. As a general rule, use files 100 MB-1 GB in size, as Redshift Spectrum and S3 are optimized for reading this object size. However, the number of files operating on a query is directly correlated with the parallelism achievable by a query. There is an inverse relationship between file size and count: the bigger the files, the fewer files there are for the same dataset. Consequently, there is a trade-off between optimizing for object read performance, and the amount of parallelism achievable on a particular query. Large files are best for large scans as the query likely operates on sufficiently large number of files. For queries that are more selective and for which fewer files are operating, you may find that smaller files allow for more parallelism.
  • Data format. Redshift Spectrum supports various data formats. Columnar formats like Parquet can sometimes lead to substantial performance benefits by providing compression and more efficient I/O for certain workloads. Generally, format types like Parquet should be used for query workloads involving large scans, and high attribute selectivity. Again, there are trade-offs as formats like Parquet require more compute power to process than plaintext. For queries on smaller subsets of data, the I/O efficiency benefit of Parquet is diminished. At some point, Parquet may perform the same or slower than plaintext. Latency, compression rates, and the trade-off between user experience and cost should drive your decision.

To help illustrate how Redshift Spectrum performs on these large aggregation workloads, run a basic query that aggregates the entire ~3.7 billion record dataset on Redshift Spectrum, and compared that with running the query exclusively on Amazon Redshift:

SELECT uv.custKey, COUNT(uv.custKey)
FROM <your clickstream table> as uv
GROUP BY uv.custKey
ORDER BY uv.custKey ASC

For the Amazon Redshift test case, the clickstream data is loaded, and distributed evenly across all nodes (even distribution style) with optimal column compression encodings prescribed by the Amazon Redshift’s ANALYZE command.

The Redshift Spectrum test case uses a Parquet data format with each file containing all the data for a particular customer in a month. This results in files mostly in the range of 220-280 MB, and in effect, is the largest file size for this partitioning scheme. If you run tests with the other datasets provided, you see that this data format and size is optimal and out-performs others by ~60X. 

Performance differences will vary depending on the scenario. The important takeaway is to understand the testing strategy and the workload characteristics where Redshift Spectrum is likely to yield performance benefits. 

The following chart compares the query execution time for the two scenarios. The results indicate that you would have to pay for 12 X DC1.Large nodes to get performance comparable to using a small Amazon Redshift cluster that leverages Redshift Spectrum. 

Chart showing simple aggregation on ~3.7 billion records

So you’ve validated that Spectrum excels at performing large aggregations. Could you benefit by pushing more work down to Redshift Spectrum in your original query? It turns out that you can, by making the following modification:

The clickstream data is stored at a day-level granularity for each customer while your query rolls up the data to the month level per customer. In the earlier query that uses the day/month partition key, you optimized the query so that it only scans and retrieves the data required, but the day level data is still sent back to your Amazon Redshift cluster for joining and aggregation. The query shown here pushes aggregation work down to Redshift Spectrum as indicated by the query plan:

In this query, Redshift Spectrum aggregates the clickstream data to the month level before it is returned to the Amazon Redshift cluster and joined with the dimension tables. This query should complete in about 4 seconds, which is roughly twice as fast as only using the partition key. The speed increase is evident upon reviewing the SVL_S3QUERY_SUMMARY table:

  • Bytes scanned is 21.6X less because of the Parquet data format.
  • Only 90 records are returned back to the Amazon Redshift cluster as a result of the push-down, instead of ~66.2 million, leading to substantially less join overhead, and about 530 MB less data sent back to your cluster.
  • No adverse change in average parallelism.

Assessing the value of Amazon Redshift vs. Redshift Spectrum

At this point, you might be asking yourself, why would I ever not use Redshift Spectrum? Well, you still get additional value for your money by loading data into Amazon Redshift, and querying in Amazon Redshift vs. querying S3.

In fact, it turns out that the last version of our query runs even faster when executed exclusively in native Amazon Redshift, as shown in the following chart:

Chart comparing Amazon Redshift vs. Redshift Spectrum with pushdown aggregation over 3 months of data

As a general rule, queries that aren’t dominated by I/O and which involve multiple joins are better optimized in native Amazon Redshift. For instance, the performance difference between running the partition key query entirely in Amazon Redshift versus with Redshift Spectrum is twice as large as that that of the pushdown aggregation query, partly because the former case benefits more from better join performance.

Furthermore, the variability in latency in native Amazon Redshift is lower. For use cases where you have tight performance SLAs on queries, you may want to consider using Amazon Redshift exclusively to support those queries.

On the other hand, when you perform large scans, you could benefit from the best of both worlds: higher performance at lower cost. For instance, imagine that you wanted to enable your business analysts to interactively discover insights across a vast amount of historical data. In the example below, the pushdown aggregation query is modified to analyze seven years of data instead of three months:

SELECT c.c_name, c.c_mktsegment, t.prettyMonthYear, uv.totalRevenue
WHERE customer <= 3 and visitYearMonth >= 199201
FROM dwdate WHERE d_yearmonthnum >= 199201) as t
ORDER BY c.c_name, c.c_mktsegment, uv.visitYearMonth ASC

This query requires scanning and aggregating nearly 1.9 billion records. As shown in the chart below, Redshift Spectrum substantially speeds up this query. A large Amazon Redshift cluster would have to be provisioned to support this use case. With the aid of Redshift Spectrum, you could use an existing small cluster, keep a single copy of your data in S3, and benefit from economical, durable storage while only paying for what you use via the pay per query pricing model.

Chart comparing Amazon Redshift vs. Redshift Spectrum with pushdown aggregation over 7 years of data


Redshift Spectrum lowers the time to value for deeper insights on customer data queries spanning the data lake and data warehouse. It can enable interactive analysis on datasets in cases that weren’t economically practical or technically feasible before.

There are cases where you can get the best of both worlds from Redshift Spectrum: higher performance at lower cost. However, there are still latency-sensitive use cases where you may want native Amazon Redshift performance. For more best practice tips, see the 10 Best Practices for Amazon Redshift post.

Please visit the Amazon Redshift Spectrum PoC Environment Github page. If you have questions or suggestions, please comment below.


Additional Reading

Learn more about how Amazon Redshift Spectrum extends data warehousing out to exabytes – no loading required.

About the Author

Dylan Tong is an Enterprise Solutions Architect at AWS. He works with customers to help drive their success on the AWS platform through thought leadership and guidance on designing well architected solutions. He has spent most of his career building on his expertise in data management and analytics by working for leaders and innovators in the space.



Hacking a Gene Sequencer by Encoding Malware in a DNA Strand

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2017/08/hacking_a_gene_.html

One of the common ways to hack a computer is to mess with its input data. That is, if you can feed the computer data that it interprets — or misinterprets — in a particular way, you can trick the computer into doing things that it wasn’t intended to do. This is basically what a buffer overflow attack is: the data input overflows a buffer and ends up being executed by the computer process.

Well, some researchers did this with a computer that processes DNA, and they encoded their malware in the DNA strands themselves:

To make the malware, the team translated a simple computer command into a short stretch of 176 DNA letters, denoted as A, G, C, and T. After ordering copies of the DNA from a vendor for $89, they fed the strands to a sequencing machine, which read off the gene letters, storing them as binary digits, 0s and 1s.

Erlich says the attack took advantage of a spill-over effect, when data that exceeds a storage buffer can be interpreted as a computer command. In this case, the command contacted a server controlled by Kohno’s team, from which they took control of a computer in their lab they were using to analyze the DNA file.

News articles. Research paper.

How To Send Ethereum Transactions With Java

Post Syndicated from Bozho original https://techblog.bozho.net/send-ethereum-transactions-java/

After I’ve expressed my concerns about the blockchain technology, let’s get a bit more practical with the blockchain. In particular, with Ethereum.

I needed to send a transaction with Java, so I looked at EthereumJ. You have three options:

  • Full node – you enable syncing, which means the whole blockchain gets downloaded. It takes a lot of time, so I abandoned that approach
  • “Light” node – you disable syncing, so you just become part of the network, but don’t fetch any parts of the chain. Not entirely sure, but I think this corresponds to the “light” mode of geth (the ethereum CLI). You are able to send messages (e.g. transaction messages) to other peers to process and store on the blockchain, but you yourself do not have the blockchain.
  • Offline (no node) – just create and sign the transaction, compute its raw representation (in the ethereum RLP format) and push it to the blockchain via a centralized API, e.g. the etherscan.io API. Etherscan is itself a node on the network and it can perform all of the operations (so it serves as a proxy)

Before going further, maybe it’s worth pointing out a few general properties of the blockchain (the ethereum one and popular cryptocurrencies at least) – it is a distributed database, relying on a peer-to-peer (overlay) network, formed by whoever has a client software running (wallet or otherwise). Transactions are in the form of “I (private key owner) want to send this amount to that address”. Transactions can have additional data stored inside them, e.g. representing what they are about. Transactions then get verified by peers (currently using a Proof-of-work based consensus) and get stored on the blockchain, which means every connected peer gets the newly created blocks (each block consisting of multiple transactions). That’s the blockchain in short, and Ethereum is no exception.

Why you may want to send transactions? I can’t think of a simple and obvious use-case, maybe you just want to implement a better wallet than the existing ones. For example in my case I wanted to store the head of a hash chain on the blockchain so that it cannot be tampered with.

In my particular case I was more interested in storing a particular piece of data as part of the transaction, rather than the transaction itself, so I had two nodes that sent very small transactions to each other (randomly choosing sender and recipient). I know I could probably have done that with a smart contract instead, but “one step at a time”. The initial code can be found here, and is based heavily on the EthereumJ samples. Since EthereumJ uses spring internally, and my application uses spring, it took some extra effort to allow for two nodes, but that’s not so relevant to the task at hand. The most important piece of the code can be seen further below in this post, only slightly modified.

You should have a user.conf file on the classpath with some defaults, and it can be based on the default ethereumj config. The more important part is the external user1 and user2 conf files (which in the general scenario can just be one conf file). Here’s a sample one, with the following important parameters:

  • peer.networkId – whether you are using the real production network (=1), or a test network (=3). Obviously, for anything than production you’d want a test network. On test networks you can get free ether by utilizing a faucet. In order to use a test network there are two more parameters below – blockchain.config.name = ropsten and genesis = ropsten.json. Note that there are more test networks at the moment, for experimenting with alternatives to proof-of-work.
  • peer.privateKey – this is the most important bit. It is your secret key which gives you control over your blockchain “account”. Only using that private key you can sign transactions (using an ellptic curve algorithm). The private key has a corresponding public key, which is basically your address on the network – if anyone wants to send funds, he sends them to your public key. But only you can then send funds from your account, as nobody else owns the private key. Which means you have to protect it. In this case it’s in plaintext in a file, which may not be ideal if you operate with big amounts of ether. Consider using some key-management solution (as outlined here)
  • peer.ip.list – this is optional, but preferable – you need to have a list of peers to connect to in order to bootstrap your client and make it part of the network. The peers there are connected to other peers, and so on, and so forth, so in the end it’s a single interconnected network. Note that in combination with the port number, that requires some additional network configuration if you are using that on a server/cluster/stack – you’d have to open some ports and allow outgoing and incoming connections.
  • database.dir – this is the directory where the blockchain and the list of discovered peers will be stored. It uses leveldb, and what I found out is that ethereumj uses an outdated leveldb which didn’t work on my machine. So I excluded them and manually used newer versions
  • sync.enabled – whether you want to fetch the blockchain or not. Normally you don’t need to, as it takes a lot of time, but that way you are not a full node and don’t contribute to the network.

As I noted earlier, I didn’t need a full node, I just needed to send a transaction. The light node would do (the difference should be simply switching sync.enabled from true to false), but after initially successfully connecting to peers, I started getting weird exceptions I didn’t have time to go into, so I couldn’t join the network anymore (maybe because of the crappy wifi I’m currently using).

Fortunately, there is a completely “offline” approach – use an external API to publish your transactions. All you need is your private key and a library (EthereumJ in this case) to prepare your transaction. So you can forget everything you read in the previous paragraphs. What you need is just the RLP encoded transaction after you have signed it. E.g.:

byte[] nonce = ByteUtil.intToBytesNoLoadZeroes(getTransactionCount(senderAddress) + 1);
byte[] gasPrice = getGasPrice();
Transaction tx = new Transaction(
    ByteUtil.bigIntegerToBytes(BigInteger.valueOf(1)),  // 1 gwei
byte[] rawTx = tx.getEncoded();
restTemplate.getForObject(etherscanUrl, String.class, "0x" + BaseEncoding.base16().encode(rawTx));

In this example, I use the Etherscan.io API (there’s also a test one for the Ropsten network). Note: it doesn’t seem to be documented, but you have to pass a User-Agent header that matches your application name. It also has a manual entry form to test your transactions (the link is for the Ropsten test network).

What are the parameters above?

  • nonce – this is a sequence number for transactions per user (=per private key). Each subsequent transaction should have a nonce that is the nonce of the previous + 1. That way nobody can replay the same transaction and drain the funds of the sender (the transaction that gets signed contains the nonce, so you cannot use the same raw transaction representation and just resubmit it). How to obtain the nonce? If you are connected to the Ethereum network, there’s a ethereum.getRepository().getNonce(fromAddress);. However, in a disconnected scenario, you’d need to obtain the current number of transactions for the sender, and then increment it. This is done via the eth_getTransactionCount endpoint. Note that it’s returned as hexadecimal, so you have to parse it, e.g. {"jsonrpc":"2.0","result":"0x1","id":73}
  • gas price, maximum gas price – these are used to cover the transaction costs (sending isn’t for free). You can read more here. You can obtain the current gas price by calling the “eth_gasPrice” API endpoint. Probably it’s a good idea to actually fetch the gas price periodically and cache it for a short period, rather than fetching it for every transaction. If you are connected to the network, you can obtain the gas price automatically.
  • receiverAddress – a byte array representing the public key of the recipient
  • value – how much ether you want to send. The smallest unit is actually a “gwei”, and the value is specified in gweis (a fraction of 1 ETH)
  • data – any additional data that you want to put in the transaction.
  • chainId – this is again related to which network you are using. Production=1, Ropsten test network=3. If you are curious why you have to encode it in a transaction, you can read here.

After that you sign the raw representation of the transaction with your private key (the raw representation is RLP (Recursive Length Prefix)). And then you send it to the API (you’d need a key for that, which you can get at Etherscan and include it in the URL). It’s almost identical to what you would’ve done if you were connected. But now you are relying on a central party (Etherscan) instead of becoming part of the network.

It may look “easy”, and when you’ve already done it and grasped it, it sounds like a piece of cake, but there are too many details that nobody abstracts from you, so you have to have the full picture before even being able to push a single transaction. What a nonce is, what a chainId is, what a test network is, how to get test ether (the top google result for a ropsten faucet doesn’t work at the moment, so you have to figure that out as well), then figure out whether you want to sync the chain or not, to be part of the network or not, to resolve weird connectivity issues and network configuration. And that’s not even mentioning smart contracts. I’m not saying it’s bad, it’s just not simple enough and that’s a barrier to wider adoption. That probably applies to most of programming, though. Anyway, I hope the above examples can get people started more easily.

The post How To Send Ethereum Transactions With Java appeared first on Bozho's tech blog.

Deploying an NGINX Reverse Proxy Sidecar Container on Amazon ECS

Post Syndicated from Nathan Peck original https://aws.amazon.com/blogs/compute/nginx-reverse-proxy-sidecar-container-on-amazon-ecs/

Reverse proxies are a powerful software architecture primitive for fetching resources from a server on behalf of a client. They serve a number of purposes, from protecting servers from unwanted traffic to offloading some of the heavy lifting of HTTP traffic processing.

This post explains the benefits of a reverse proxy, and explains how to use NGINX and Amazon EC2 Container Service (Amazon ECS) to easily implement and deploy a reverse proxy for your containerized application.


NGINX is a high performance HTTP server that has achieved significant adoption because of its asynchronous event driven architecture. It can serve thousands of concurrent requests with a low memory footprint. This efficiency also makes it ideal as a reverse proxy.

Amazon ECS is a highly scalable, high performance container management service that supports Docker containers. It allows you to run applications easily on a managed cluster of Amazon EC2 instances. Amazon ECS helps you get your application components running on instances according to a specified configuration. It also helps scale out these components across an entire fleet of instances.

Sidecar containers are a common software pattern that has been embraced by engineering organizations. It’s a way to keep server side architecture easier to understand by building with smaller, modular containers that each serve a simple purpose. Just like an application can be powered by multiple microservices, each microservice can also be powered by multiple containers that work together. A sidecar container is simply a way to move part of the core responsibility of a service out into a containerized module that is deployed alongside a core application container.

The following diagram shows how an NGINX reverse proxy sidecar container operates alongside an application server container:

In this architecture, Amazon ECS has deployed two copies of an application stack that is made up of an NGINX reverse proxy side container and an application container. Web traffic from the public goes to an Application Load Balancer, which then distributes the traffic to one of the NGINX reverse proxy sidecars. The NGINX reverse proxy then forwards the request to the application server and returns its response to the client via the load balancer.

Reverse proxy for security

Security is one reason for using a reverse proxy in front of an application container. Any web server that serves resources to the public can expect to receive lots of unwanted traffic every day. Some of this traffic is relatively benign scans by researchers and tools, such as Shodan or nmap:

[18/May/2017:15:10:10 +0000] "GET /YesThisIsAReallyLongRequestURLbutWeAreDoingItOnPurposeWeAreScanningForResearchPurposePleaseHaveALookAtTheUserAgentTHXYesThisIsAReallyLongRequestURLbutWeAreDoingItOnPurposeWeAreScanningForResearchPurposePleaseHaveALookAtTheUserAgentTHXYesThisIsAReallyLongRequestURLbutWeAreDoingItOnPurposeWeAreScanningForResearchPurposePleaseHaveALookAtTheUserAgentTHXYesThisIsAReallyLongRequestURLbutWeAreDoingItOnPurposeWeAreScanningForResearchPurposePleaseHaveALookAtTheUserAgentTHXYesThisIsAReallyLongRequestURLbutWeAreDoingItOnPurposeWeAreScanningForResearchPurposePleaseHaveALookAtTheUserAgentTHXYesThisIsAReallyLongRequestURLbutWeAreDoingItOnPurposeWeAreScanningForResearchPurposePleaseHaveALookAtTheUserAgentTHXYesThisIsAReallyLongRequestURLbutWeAreDoingItOnPurposeWeAreScanningForResearchPurposePleaseHaveALookAtTheUserAgentTHXYesThisIsAReallyLongRequestURLbutWeAreDoingItOnPurposeWeAreScanningForResearchPurposePleaseHaveALookAtTheUserAgentTHXYesThisIsAReallyLongRequestURLbutWeAreDoingItOnPurposeWeAreScann HTTP/1.1" 404 1389 - Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/46.0.2490.86 Safari/537.36
[18/May/2017:18:19:51 +0000] "GET /clientaccesspolicy.xml HTTP/1.1" 404 322 - Cloud mapping experiment. Contact [email protected]

But other traffic is much more malicious. For example, here is what a web server sees while being scanned by the hacking tool ZmEu, which scans web servers trying to find PHPMyAdmin installations to exploit:

[18/May/2017:16:27:39 +0000] "GET /mysqladmin/scripts/setup.php HTTP/1.1" 404 391 - ZmEu
[18/May/2017:16:27:39 +0000] "GET /web/phpMyAdmin/scripts/setup.php HTTP/1.1" 404 394 - ZmEu
[18/May/2017:16:27:39 +0000] "GET /xampp/phpmyadmin/scripts/setup.php HTTP/1.1" 404 396 - ZmEu
[18/May/2017:16:27:40 +0000] "GET /apache-default/phpmyadmin/scripts/setup.php HTTP/1.1" 404 405 - ZmEu
[18/May/2017:16:27:40 +0000] "GET /phpMyAdmin- HTTP/1.1" 404 397 - ZmEu
[18/May/2017:16:27:40 +0000] "GET /mysql/scripts/setup.php HTTP/1.1" 404 386 - ZmEu
[18/May/2017:16:27:41 +0000] "GET /admin/scripts/setup.php HTTP/1.1" 404 386 - ZmEu
[18/May/2017:16:27:41 +0000] "GET /forum/phpmyadmin/scripts/setup.php HTTP/1.1" 404 396 - ZmEu
[18/May/2017:16:27:41 +0000] "GET /typo3/phpmyadmin/scripts/setup.php HTTP/1.1" 404 396 - ZmEu
[18/May/2017:16:27:42 +0000] "GET /phpMyAdmin- HTTP/1.1" 404 399 - ZmEu
[18/May/2017:16:27:44 +0000] "GET /administrator/components/com_joommyadmin/phpmyadmin/scripts/setup.php HTTP/1.1" 404 418 - ZmEu
[18/May/2017:18:34:45 +0000] "GET /phpmyadmin/scripts/setup.php HTTP/1.1" 404 390 - ZmEu
[18/May/2017:16:27:45 +0000] "GET /w00tw00t.at.blackhats.romanian.anti-sec:) HTTP/1.1" 404 401 - ZmEu

In addition, servers can also end up receiving unwanted web traffic that is intended for another server. In a cloud environment, an application may end up reusing an IP address that was formerly connected to another service. It’s common for misconfigured or misbehaving DNS servers to send traffic intended for a different host to an IP address now connected to your server.

It’s the responsibility of anyone running a web server to handle and reject potentially malicious traffic or unwanted traffic. Ideally, the web server can reject this traffic as early as possible, before it actually reaches the core application code. A reverse proxy is one way to provide this layer of protection for an application server. It can be configured to reject these requests before they reach the application server.

Reverse proxy for performance

Another advantage of using a reverse proxy such as NGINX is that it can be configured to offload some heavy lifting from your application container. For example, every HTTP server should support gzip. Whenever a client requests gzip encoding, the server compresses the response before sending it back to the client. This compression saves network bandwidth, which also improves speed for clients who now don’t have to wait as long for a response to fully download.

NGINX can be configured to accept a plaintext response from your application container and gzip encode it before sending it down to the client. This allows your application container to focus 100% of its CPU allotment on running business logic, while NGINX handles the encoding with its efficient gzip implementation.

An application may have security concerns that require SSL termination at the instance level instead of at the load balancer. NGINX can also be configured to terminate SSL before proxying the request to a local application container. Again, this also removes some CPU load from the application container, allowing it to focus on running business logic. It also gives you a cleaner way to patch any SSL vulnerabilities or update SSL certificates by updating the NGINX container without needing to change the application container.

NGINX configuration

Configuring NGINX for both traffic filtering and gzip encoding is shown below:

http {
  # NGINX will handle gzip compression of responses from the app server
  gzip on;
  gzip_proxied any;
  gzip_types text/plain application/json;
  gzip_min_length 1000;
  server {
    listen 80;
    # NGINX will reject anything not matching /api
    location /api {
      # Reject requests with unsupported HTTP method
      if ($request_method !~ ^(GET|POST|HEAD|OPTIONS|PUT|DELETE)$) {
        return 405;
      # Only requests matching the whitelist expectations will
      # get sent to the application server
      proxy_pass http://app:3000;
      proxy_http_version 1.1;
      proxy_set_header Upgrade $http_upgrade;
      proxy_set_header Connection 'upgrade';
      proxy_set_header Host $host;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_cache_bypass $http_upgrade;

The above configuration only accepts traffic that matches the expression /api and has a recognized HTTP method. If the traffic matches, it is forwarded to a local application container accessible at the local hostname app. If the client requested gzip encoding, the plaintext response from that application container is gzip-encoded.

Amazon ECS configuration

Configuring ECS to run this NGINX container as a sidecar is also simple. ECS uses a core primitive called the task definition. Each task definition can include one or more containers, which can be linked to each other:

  "containerDefinitions": [
       "name": "nginx",
       "image": "<NGINX reverse proxy image URL here>",
       "memory": "256",
       "cpu": "256",
       "essential": true,
       "portMappings": [
           "containerPort": "80",
           "protocol": "tcp"
       "links": [
       "name": "app",
       "image": "<app image URL here>",
       "memory": "256",
       "cpu": "256",
       "essential": true
   "networkMode": "bridge",
   "family": "application-stack"

This task definition causes ECS to start both an NGINX container and an application container on the same instance. Then, the NGINX container is linked to the application container. This allows the NGINX container to send traffic to the application container using the hostname app.

The NGINX container has a port mapping that exposes port 80 on a publically accessible port but the application container does not. This means that the application container is not directly addressable. The only way to send it traffic is to send traffic to the NGINX container, which filters that traffic down. It only forwards to the application container if the traffic passes the whitelisted rules.


Running a sidecar container such as NGINX can bring significant benefits by making it easier to provide protection for application containers. Sidecar containers also improve performance by freeing your application container from various CPU intensive tasks. Amazon ECS makes it easy to run sidecar containers, and automate their deployment across your cluster.

To see the full code for this NGINX sidecar reference, or to try it out yourself, you can check out the open source NGINX reverse proxy reference architecture on GitHub.

– Nathan

CyberChef – Cyber Swiss Army Knife

Post Syndicated from Darknet original http://feedproxy.google.com/~r/darknethackers/~3/SOhld_nebGs/

CyberChef is a simple, intuitive web app for carrying out all manner of “cyber” operations within a web browser. These operations include simple encoding like XOR or Base64, more complex encryption like AES, DES and Blowfish, creating binary and hexdumps, compression and decompression of data, calculating hashes and checksums, IPv6 and X.509…

Read the full post at darknet.org.uk