viernes, mayo 22, 2020

ANNOUNCEMENT: Submitters Of Papers And Training For Global AppSec DC 2019 (Formerly AppSec USA)

We had an overwhelming turnout out of submissions for Call for Papers and Call for Training for the OWASP Global AppSec DC 2019 (formerly AppSec USA)  We want to give each submission the time deserved to evaluate each before choosing.  Keeping that in mind the notifications of acceptance and thanks will be CHANGED to July 1, 2019.  We appreciate your understanding and patience in this matter.

Read more
  1. Hacking Web Sql Injection
  2. Portatil Para Hacking
  3. Ethical Hacking Certification
  4. Kali Linux Hacking
  5. Hacking Libro
  6. Elladodelmal
  7. Aprender A Hackear Desde Cero

Sslmerge - Tool To Help You Build A Valid SSL Certificate Chain From The Root Certificate To The End-User Certificate


Is an open source tool to help you build a valid SSL certificate chain from the root certificate to the end-user certificate. Also can help you fix the incomplete certificate chain and download all missing CA certificates.

How To Use
It's simple:
# Clone this repository
git clone https://github.com/trimstray/sslmerge

# Go into the repository
cd sslmerge

# Install
./setup.sh install

# Run the app
sslmerge -i /data/certs -o /data/certs/chain.crt
  • symlink to bin/sslmerge is placed in /usr/local/bin
  • man page is placed in /usr/local/man/man8

Parameters
Provides the following options:
  Usage:
sslmerge <option|long-option>

Examples:
sslmerge --in Root.crt --in Intermediate1.crt --in Server.crt --out bundle_chain_certs.crt
sslmerge --in /tmp/certs --out bundle_chain_certs.crt --with-root
sslmerge -i Server.crt -o bundle_chain_certs.crt

Options:
--help show this message
--debug displays information on the screen (debug mode)
-i, --in add certificates to merge (certificate file, multiple files or directory with ssl certificates)
-o, --out saves the result (chain) to file
--with-root add root certificate to the certificate chain

How it works
Let's start with ssllabs certificate chain. They are delivered together with the sslmerge and can be found in the example/ssllabs.com directory which additionally contains the all directory (containing all the certificates needed to assemble the chain) and the server_certificate directory (containing only the server certificate).
The correct chain for the ssllabs.com domain (the result of the openssl command):
Certificate chain
0 s:/C=US/ST=California/L=Redwood City/O=Qualys, Inc./CN=ssllabs.com
i:/C=US/O=Entrust, Inc./OU=See www.entrust.net/legal-terms/OU=(c) 2012 Entrust, Inc. - for authorized use only/CN=Entrust Certification Authority - L1K
1 s:/C=US/O=Entrust, Inc./OU=See www.entrust.net/legal-terms/OU=(c) 2012 Entrust, Inc. - for authorized use only/CN=Entrust Certification Authority - L1K
i:/C=US/O=Entrust, Inc./OU=See www.entrust.net/legal-terms/OU=(c) 2009 Entrust, Inc. - for authorized use only/CN=Entrust Root Certification Authority - G2
2 s:/C=US/O=Entrust, Inc./OU=See www.entrust.net/legal-terms/OU=(c) 2009 Entrust, Inc. - for authorized use only/CN=Entrust Root Certification Authority - G2
i:/C=US/O=Entrust, Inc./OU=www.entrust.net/CPS is incorporated by reference/OU=(c) 2006 Entrust, Inc./CN=Entrust Root Certification Authority
The above code presents a full chain consisting of:
  • Identity Certificate (Server Certificate)
    issued for ssllabs.com by Entrust Certification Authority - L1K
  • Intermediate Certificate
    issued for Entrust Certification Authority - L1K by Entrust Root Certification Authority - G2
  • Intermediate Certificate
    issued for Entrust Root Certification Authority - G2 by Entrust Root Certification Authority
  • Root Certificate (Self-Signed Certificate)
    issued for Entrust Root Certification Authority by Entrust Root Certification Authority

Scenario 1
In this scenario, we will chain all delivered certificates. Example of running the tool:

Scenario 2
In this scenario, we only use the server certificate and use it to retrieve the remaining required certificates. Then, as above, we will combine all the provided certificates. Example of running the tool:

Certificate chain
In order to create a valid chain, you must provide the tool with all the necessary certificates. It will be:
  • Server Certificate
  • Intermediate CAs and Root CAs
This is very important because without it you will not be able to determine the beginning and end of the chain.
However, if you look inside the generated chain after generating with sslmerge, you will not find the root certificate there. Why?
Because self-signed root certificates need not/should not be included in web server configuration. They serve no purpose (clients will always ignore them) and they incur a slight performance (latency) penalty because they increase the size of the SSL handshake.
If you want to add a root certificate to the certificate chain, call the utility with the --with-root parameter.

Certification Paths
Sslmerge allows use of two certification paths:

Output comments
When generating the chain of certificates, sslmerge displays comments with information about certificates, including any errors.
Here is a list of all possibilities:

not found identity (end-user, server) certificate
The message is displayed in the absence of a server certificate that is the beginning of the chain. This is a unique case because in this situation the sslmerge ends its operation displaying only this information. The server certificate is the only certificate required to correctly create a chain. Without this certificate, the correct chain will not be created.

found correct identity (end-user, server) certificate
The reverse situation here - message displayed when a valid server certificate is found.

not found first intermediate certificate
This message appears when the first of the two intermediate certificates is not found. This information does not explicitly specify the absence of a second intermediate certificate and on the other hand it allows to determine whether the intermediate certificate to which the server certificate was signed exists. Additionally, it can be displayed if the second intermediate certificate has been delivered.

not found second intermediate certificate
Similar to the above, however, it concerns the second intermediate certificate. However, it is possible to create the chain correctly using the second certification path, e.g. using the first intermediate certificate and replacing the second with the main certificate.

one or more intermediate certificate not found
This message means that one or all of the required intermediate certificates are missing and displayed in the absence of the root certificate.

found 'n' correct intermediate certificate(s)
This message indicates the number of valid intermediate certificates.

not found correct root certificate
The lack of the root certificate is treated as a warning. Of course, when configuring certificates on the server side, it is not recommended to attach a root certificate, but if you create it with the sslmerge, it treats the chain as incomplete displaying information about the incorrect creation of the chain.

an empty CN field was found in one of the certificates
This message does not inform about the error and about the lack of the CN field what can happen with some certificates (look at example/google.com). Common Name field identifies the host name associated with the certificate. There is no requirement in RFC3280 for an Issuer DN to have a CN. Most CAs do include a CN in the Issuer DN, but some don't, such as this Equifax CA.

Requirements
Sslmerge uses external utilities to be installed before running:

Other

Contributing
See this.

Project architecture
See this.


Related links


  1. Etica Definicion
  2. Hacking Roblox
  3. Hacking Informatico
  4. Hacking Netflix Account

How To Switch From 32-Bit Windows 10 To 64-Bit Windows 10

Microsoft offers Windows 10 as a free upgrade for computers running a genuine copy of Windows 7 or Windows 8.1. Also, similar to previous releases, the operating system is available on different editions and two versions: 32-bit and 64-bit.While upgrading from Windows 10 Home to Windows 10 Pro is not free, what many people are unfamiliar with is that Microsoft won't ask for more money to upgrade from a 32-bit to a 64-bit version.
However, the upgrade path only allows moving from a qualifying version to its equivalent edition on the same architecture. This limit means that if your PC is running a 32-bit version of Windows 8.1, after the upgrade you'll be stuck with the 32-bit version of Windows 10 — even if your computer's processor can handle the 64-bit version. The only solution is to make a clean installation of the operating system and reconfigure all your apps and settings.
iemhacker-how-to-switch-from-32-bit-windows-to 64bit
In this Windows 10 guide, we'll walk you through the steps to verify whether your computer in fact includes support for a 64-bit version and we'll guide you through the upgrade process to Windows 10 (x64).

Make sure Windows 10 64-bit is compatible with your PC

A 64-bit version of Windows can only be installed on computers with capable hardware. As such, the first thing you need to do is to determine whether your computer has a 64-bit processor.
You can easily get this information from the Settings app.
  1. Use the Windows key + I keyboard shortcut to open the Settings app.
  2. Click System.
  3. Click About.
  4. Under System type, you will see two pieces of information: if it says 32-bit operating system, x64-based processor, then it means that your PC is running a 32-bit version of Windows 10 on a 64-bit processor. If it says 32-bit operating system, x86-based processor, then your computer doesn't support Windows 10 (64-bit).

Make Sure Your Processor is 64-bit Capable

First thing's first. Before even thinking of upgrading to 64-bit Windows, you'll need to confirm that the CPU in your computer is 64-bit capable. To do so, head to Settings > System > About. On the right-hand side of the window, look for the "System type" entry.

You'll see one of three things here:

  • 64-bit operating system, x64-based processor. Your CPU does support 64-bit and you already have the 64-bit version of Windows installed.
  • 32-bit operating system, x86-based processor. Your CPU does not support 64-bit and you have the 32-bit version of Windows installed.
  • 32-bit operating system, x64-based processor. Your CPU supports 64-bit, but you have the 32-bit version of Windows installed.
If you see the first entry on your system, you don't really need this article. If you see the second entry, you won't be able to install the 64-bit version of Windows on your system at all. But if you see the last entry on your system—"32-bit operating system, x64-based processor"—then you're in luck. This means you're using a 32-bit version of Windows 10 but your CPU can run a 64-bit version, so if you see it, it's time to move on to the next section.
Make Sure Your PC's Hardware Has 64-bit Drivers Available
Even if your processor is 64-bit compatible, you might want to consider whether your computer's hardware will work properly with a 64-bit version of Windows. 64-bit versions of Windows require 64-bit hardware drivers, and the 32-bit versions you're using on your current Windows 10 system won't work.
Modern hardware should certainly offer 64-bit drivers, but very old hardware may no longer be supported and the manufacturer may have never offered 64-bit drivers. To check for this, you can visit the manufacturer's driver download web pages for your hardware and see if 64-bit drivers are available. You shouldn't necessarily need to download these from the manufacturer's website, though. They are likely included with Windows 10 or automatically will be downloaded from Windows Update. But old hardware—for example, a particularly ancient printer—simply may not offer 64-bit drivers.

Upgrade by Performing a Clean Install

You'll need to perform a clean install to get to the 64-bit version of Windows 10 from the 32-bit one. Unfortunately, there's no direct upgrade path.
Warning: Back up your important files before continuing and also make sure you have what you need to reinstall your programs. This process will wipe your whole hard disk, including Windows, installed programs, and personal files.
First, if you haven't upgraded to Windows 10 yet, you'll need to use the upgrade tool to upgrade. You'll get the 32-bit version of Windows 10 if you were previously using a 32-bit version of Windows 7 or 8.1. But the upgrade process will give your PC a Windows 10 license. After upgrading, be sure to check that your current 32-bit version of Windows 10 is activated under Settings > Update & security > Activation.
Once you're using an activated version of the 32-bit Windows 10, download the Windows 10 media creation tool from Microsoft. If you're using the 32-bit version of Windows 10 at the moment, you'll have to download and run the 32-bit tool.
When you run the tool, select "Create installation media for another PC" and use the tool to create a USB drive or burn a disc with Windows 10. As you click through the wizard, you'll be asked whether you want to create 32-bit or 64-bit installation media. Select the "64-bit (x64)" architecture.
Next, restart your computer (you did back everything up, right?) and boot from the installation media. Install the 64-bit Windows 10, selecting "Custom install" and overwriting your current version of Windows. When you're asked to insert a product key, skip the process and continue. You'll have to skip two of these prompts in total. After you reach the desktop, Windows 10 will automatically check in with Microsoft and activate itself. You'll now be running the 64-bit edition of Windows on your PC.
If you want to go back to the 32-bit version of Windows, you'll need to download the media creation tool—the 64-bit version, if you're running the 64-bit version of Windows 10—and use it to create 32-bit installation media. Boot from that installation media and do another clean install—this time installing the 32-bit version over the 64-bit version.

Final Words :

Finally, you are aware of the way through which you could be able to switch from the 32-bit windows to 64-bit windows really easily. There will be no difference in the functions or the working of the windows yet the only change that you will get is the more advanced architecture that is compatible with numerous high-end apps. If you are thinking to switch your windows to the 64-bit version then make sure you first check for your hardware compatibility. Hopefully, you would have liked the information of this post, please share this post with others if you really liked it. Provide us your valuable views regarding this post through using the comments section below. At last nevertheless thanks for reading this post!
Related articles
  1. Hacking Linkedin
  2. Curso Ethical Hacking
  3. Paginas Para Hackear
  4. Growth Hacking Examples
  5. Whatsapp Hacking
  6. Herramientas Hacking Etico
  7. Manual Del Hacker
  8. Hacking Prank

How To Create Fake Email Address Within Seconds

How To Create Fake Email Address Within Seconds

How To Create Fake Email Address Within Seconds

Email address is a type of identification by which an email receiver identifies the person who sends mail to him/her. That's why while creating an email address you need to enter your personal details that must be valid. However, what if we tell you that you can create an email address that doesn't require any validation of personal details and that email address gets permanently deleted after your work is done. So here we have a method To Create Fake Email Address. By this, you can create a fake email address that will get auto-deleted after ten minutes. Just follow the below steps to proceed.

Note:  The method we are discussing is just for a known purpose and should not be used for any illegal purposes, as we will be not responsible for any wrongdoing.

How To Create Fake Email Address Within Seconds

The method of creating a fake email address is very simple and easy as these are based on online websites that will provide you a free email address without taking any personal details from you.

#1 10 Minute Mail

10 Minute Mail
10 Minute Mail
10 Minute Mail will provide you a temporary e-mail address. Any e-mails sent to that address will show automatically on the web page. You can read them, click on links, and even reply to them. The email address will expire after 10 minutes.

#2 GuerrillaMail

Guerrillamail
Guerrillamail
It is one of the most user-friendly ones out there, with this, you can get disposable email ID easily. You need to enter the details, and the fake email ID will be generated. Moreover, this also lets you send emails with attachment up to 150MB. You will be provided with a temporary email address which you can use to verify some websites which require the email address.

#3 Mailinator

Mailinator
Mailinator
Mailinator is a free, Public, Email System where you can use any inbox you want. You will be given a Mailinator address which you can use anytime a website asks for an email address. The public emails you will receive will be auto-deleted after few hours of receiving.

#4 MailDrop

MailDrop
MailDrop
Maildrop is a great idea when you want to sign up for a website but you are concerned that they might share your address with advertisers. MailDrop is powered by some of the spam filters created by Heluna, used in order to block almost all spam attempts before they even get to your MailDrop inbox. This works the same way like Mailinator in which you will be given a temporary Email address which you can use to verify sites etc.

#5 AirMail

AirMail
AirMail
AirMail is a free temporary email service, you are given a random email address you can use when registering to new websites or test-driving untrusted services. All emails received by AirMail servers are displayed automatically in your online browser inbox.
More information
  1. Raspberry Pi Hacking
  2. Libros Para Aprender A Hackear
  3. Hacking Google Home Mini
  4. Hacking Bluetooth Speaker
  5. Blog Seguridad Informática
  6. Diferencia Entre Hacker Y Cracker
  7. Paginas Para Hackear
  8. Clases De Hacker
  9. Chema Alonso Wikipedia
  10. Hacking Con Buscadores Pdf

jueves, mayo 21, 2020

Takeover - SubDomain TakeOver Vulnerability Scanner


Sub-domain takeover vulnerability occur when a sub-domain (subdomain.example.com) is pointing to a service (e.g: GitHub, AWS/S3,..) that has been removed or deleted. This allows an attacker to set up a page on the service that was being used and point their page to that sub-domain. For example, if subdomain.example.com was pointing to a GitHub page and the user decided to delete their GitHub page, an attacker can now create a GitHub page, add a CNAME file containing subdomain.example.com, and claim subdomain.example.com. For more information: here



Installation:
# git clone https://github.com/m4ll0k/takeover.git
# cd takeover
# python takeover.py
or:
wget -q https://raw.githubusercontent.com/m4ll0k/takeover/master/takeover.py && python takeover.py


Related word

  1. Hacking Attacks
  2. Hacking Xbox One
  3. Hacking Smart Tv
  4. Herramientas Growth Hacking
  5. Hacking Attacks
  6. Que Estudiar Para Ser Hacker
  7. Blackhat Hacking
  8. Aprender Hacking
  9. Codigo Hacker

Gridcoin - The Good

In this post we will take an in depth look at the cryptocurrency Gridcoin, we show how we found two critical design vulnerabilities and how we fixed them.

In the last past years we saw many scientific publications about cryptocurrencies. Some focused on theoretical parts [Source] and some on practical attacks against specific well-known cryptocurrencies, like Bitcoin [Source]. But in general there is a lack of practical research against alternative coins. Or did you know that there are currently over 830 currencies listed online? So we asked ourselves how secure are these currencies, and if they are not just re-branded forks of the Bitcoin source code?

Background

Gridcoin is an Altcoin, which is in active development since 2013. It claims to provide a high sustainability, as it has very low energy requirements in comparison to Bitcoin. It rewards users for contributing computation power to scientific projects, published on the BOINC project platform. Although Gridcoin is not as widespread as Bitcoin, its draft is very appealing as it attempts to eliminate Bitcoin's core problems. It possesses a market capitalization of $13,719,142 (2017/08/10).

Berkeley Open Infrastructure for Network Computing

To solve general scientific meaningful problems, Gridcoin draws on the well-known Berkeley Open Infrastructure for Network Computing (BOINC). It is a software platform for volunteer computing, initially released in 2002 and developed by the University of California, Berkeley. It is an open source software licensed under the GNU Lesser General Public License. The platform enables professionals in need for computation power to distribute their tasks to volunteers. Nowadays it is widely used by researchers with limited resources to solve scientific problems, for example, healing cancer, investigate global warming, finding extraterrestrial intelligence in radio signals and finding larger prime numbers.
When launching a BOINC project, its maintainer is required to set up his own BOINC server. Project volunteers may then create accounts (by submitting a username, a password and an email address) and work on specific project tasks, called workunits. The volunteers can process the project tasks and transfer their solutions with a BOINC client.

BOINC architecture

BOINC uses a client-server architecture to achieve its rich feature set. The server component handles the client requests for workunits and the problem solutions uploaded by the clients. The solutions are validated and assimilated by the server component. All workunits are created by the server component and each workunit represents a chunk of a scientific problem which is encapsulated into an application. This application consists of one or multiple in-/output files, containing binary or ASCII encoded parameters.

BOINC terminology

  • iCPID
    • The BOINC project server creates the internal Cross Project Identifier (iCPID) as a 16 byte long random value during account creation. This value is stored by the client and server. From this time on, the iCPID is included in every request and response between client and server
  • eCPID
    • The external Cross Project Identifier (eCPID) serves the purpose of identifying a volunteer across different BOINC projects without revealing the corresponding email address. It is computed by applying the cryptographic hash function MD5 to (iCPID,email) and thus has a length of 16 byte [Source].
eCPID = MD5(iCPID||email)
  • Credits
    • BOINC credits are generated whenever a host submits a solution to an assigned task. They are measured in Cobblestone, whereas one Cobblestone is equivalent to 1/200 of CPU time on a reference machine with 1,000 mega floating point operation per seconds [Source]
  • Total Credit
    • Total number of Cubblestones a user invested with his machines for scientific computations
  • Recent Average Credit (RAC)
    • RAC is defined as the average number of Cobblestones per day generated recently [Source]. If an entire week passes, the value is divided by two. Thus old credits are weakly weighted. It is recalculated whenever a host generates credit [Source].

Gridcoin

As a fork of Litecoin, Gridcoin-Research is a blockchain based cryptocurrency and shares many concepts with Bitcoin. While Bitcoin's transaction data structure and concept is used in an unmodified version, Gridcoin-Research utilizes a slightly modified block structure. A Gridcoin-Research block encapsulates a header and body. The header contains needed meta information and the body encloses transactions. Due to the hashPrevBlockHeader field, which contains the hash of the previous block-header, the blocks are linked and form the distributed ledger, the blockchain. Blocks in the blockchain are created by so called minters. Each block stores a list of recent transactions in its body and further metadata in its header. To ensure that all transactions are confirmed in a decisive order, each block-header field contains a reference to the previous one. To regulate the rate in which new blocks are appended to the blockchain and to reward BOINC contribution, Gridcoin-Research implements another concept called Proof-of-Research. Proof-of-Research is a combination of a new overhauled Proof-of-BOINC concept, which was originally designed for Gridcoin-Classic and the improved Proof-of-Stake concept, inspired by alternative cryptocurrencies.

Fig. 1: Gridcoin block structure

Gridcoin terminology

In order to understand the attacks we need to introduce some Gridcoin specific terms.
  • eCPID
    • Identifier value from BOINC used in Gridcoin to identify the researcher.
  • CPIDv2
    • contains a checksum to prove that the minter is the owner of the used eCPID. We fully describe the content of this field in the last attack section.
  • GRCAddress
    • contains the payment address of the minter.
  • ResearchAge
    • is defined as the time span between the creation time of the last Proof-of-Research generated block with the user's eCPID and the time stamp of the last block in the chain measured in days.
  • RSAWeight
    • estimates the user's Gridcoin gain for the next two weeks, based on the BOINC contribution of the past two weeks.

Proof-of-Stake

Proof-of-Stake is a Proof-of-Work replacement, which was first utilized by the cryptocurrency Peercoin in 2012. This alternative concept was developed to showcase a working Bitcoin related currency with low power consumption. Therefore, the block generation process has been overhauled. To create a new valid block for the Gridcoin blockchain the following inequality have to be satisfied:

SHA256(SHA256(kernel)) < Target * UTXO Value + RSAWeight

The kernel value represents the concatenation of the parameters listed in Table 2. The referenced unspent transaction output (UTXO) must be at least 16 hours old. The so called RSAWeight is an input value to the kernel computation, it's indicates the average BOINC work, done by a Gridcoin minter.
In direct comparison to Bitcoin's Proof-of-Work concept, it is notable that the hash of the previous block-header is not part of the kernel. Consequently, it is theoretically possible to create a block at any previous point in time in the past. To prevent this, Gridcoin-Research creates fixed interval checkpoint blocks. Once a checkpoint block is synchronized with the network, blocks with older time stamps became invalid. Considering the nature of the used kernel fields, a client with only one UTXO is able to perform a hash calculation each time nTime is updated. This occurs every second, as nTime is a UNIX time stamp. To be able to change the txPrev fields and thereby increase his hash rate, he needs to gain more UTXO by purchasing coins. Note that high UTXO and RSAWeight values mitigate the difficulty of the cryptographic puzzle, which increase the chance of finding a valid kernel. RSAWeight was explained above. Once a sufficient kernel has been found, the referenced UTXO is spent in a transaction to the creator of the block and included in the generated block. This consumes the old UTXO and generates a new one with the age of zero.

The Gridcoin-Research concept does not require much electrical power, because the maximum hash rate of an entity is limited by its owned amount of UTXOs with suitable age.

Proof-of-Research

Minters relying solely on the Proof-of-Stake rewards are called Investors. In addition to Proof-of-Stake, Gridcoin gives minters a possibility to increase their income with Proof-of-Research rewards. The Proof-of-Research concept implemented in Gridcoin-Research allows the minters to highly increase their block reward by utilizing their BOINC Credits. In this case the minter is called a Researcher.
To reward BOINC contribution, relevant BOINC data needs to be stored in each minted block. Therefore, the software uses the BOINCHash data structure, which is encapsulated in the first transaction of each block. The structure encloses the fields listed in Table 6. The minting and verification process is shown in Figure 2 and works as follows:
  1. A minter (Researcher) participates in a BOINC project A and performs computational work for it. In return the project server increases the users Total Credit value on the server. The server therefore stores the minter's email address, iCPID, eCPID and RAC.
  2. Statistical websites contact project server and down-load the statistics for all users from the project server (A).
  3. After the user earns credits, his RAC increases. Consequently, this eases the finding of a solution for the Proof-of-Stake cryptographic puzzle, and the user can create (mint) a block and broadcast it to the Gridcoin network.
  4. Another minter (Investor or Researcher) will receive the block and validate it. Therefore, he extracts the values from the BOINCHash data structure inside the block.
  5. The minter uses the eCPID from the BOINCHash to request the RAC and other needed values from a statistical website and compares them to the data extracted from the BOINCHash structure, in the event that they are equal and the block solves the cryptographic puzzle, the block is accepted.

 Fig. 2: Gridcoin architecture and minting process

Reward calculation

The total reward for a solved block is called the Subsidy and is computed as the sum of the Proof-of-Research and the Proof-of-Stake reward.
If a minter operates as an Investor (without BOINC contribution), the eCPID is set to the string Investor and all other fields of the BOINCHash are zeroed. An Investor receives only a relatively small Proof-of-Stake reward.
Because the Proof-of-Research reward is much higher than its Proof-of-Stake counterpart, contributing to BOINC projects is more worth the effort.

Statistic Website

At the beginning of the blog post, the core concept behind BOINC was described. One functionality is the creation of BOINC Credits for users, who perform computational work for the project server. This increases the competition between BOINC users and therefore has a positive effect on the amount of computational work users commit. Different websites 4 collect credit information of BOINC users from known project servers and present them online. The Gridcoin client compares the RAC and total credit values stored in a new minted block with the values stored on cpid.gridcoin.us:5000/get_user.php?cpid=eCPID where eCPID is the actual value of the researcher. If there are differences, the client declines the block. In short, statistical websites are used as control instance for Gridcoin. It is obvious that gridcoin.us administrators are able to modify values of any user. Thus, they are able to manipulate the amount of Gridcoins a minter gets for his computational work. This is crucial for the trust level and undermines the general decentralized structure of a cryptocurrency.

Project Servers

Gridcoin utilizes BOINC projects to outsource meaningful computation tasks from the currency. For many known meaningful problems there exist project servers 5 that validate solutions submitted by users, 6 and decide how many credits the users receive for their solutions. Therefore, the project servers can indirectly control the amount of Gridcoins a minter gets for his minted block via the total credit value. As a result, a Gridcoin user also needs to trust the project administrators. This is very critical since there is no transparency in the credit system of project server. If you want to know why decentralization is not yet an option, see our paper from WOOT'17.

Attacks

In addition to the trust a Gridcoin user needs to put into the project server and statistic website administrators, Gridcoin suffers from serious flaws which allows the revelation of minter identities or even stealing coins. Our attacks do not rely on the Gridcoin trust issues and the attacker does not need to be in possession of specific server administrative rights. We assume the following two simple attackers with limited capability sets. The first one, is the blockchain grabber which can download the Gridcoin blockchain from an Internet resource and runs a program on the downloaded data. The second one, the Gridcoin attacker, acts as a normal Gridcoin user, but uses a modified Gridcoin client version, in order to run our attacks.

Interestingly, the developer of Gridcoin tried to make the source code analysis somewhat harder, by obfuscating the source code of relevant functions.
 Fig. 3: Obfuscated source code in Gridcoin [Source]

Grab Gridcoin user email addresses

In order to protect the email addresses of Gridcoin Researchers, neither BOINC project websites nor statistical websites directly include these privacy critical data. The statistical websites only include eCPID entries, which are used to reward Gridcoin Researchers. However, the email addresses are hidden inside the computation of the BOINCHash (cf. Table 1). A BOINCHash is created every time a Researcher mints a new block and includes a CPIDv2 value. The CPIDv2 value contains an obfuscated email address with iCPID and a hash over the previous blockchain block.
By collecting the blockchain data and reversing the obfuscation function (cf. Figure 4 and Figure 7), the attacker gets all email addresses and iCPIDs ever used by Gridcoin Researchers. See the reversed obfuscation function in Figure 4 and Figure 5.

Evaluation

We implemented a deobfuscation function (cf. Figure 7) and executed it on the blockchain. This way, we were able to retrieve all (2709) BOINC email addresses and iCPIDs used by Gridcoin Researchers. This is a serious privacy issue and we address it with our fix (cf. The Fix).

Steal Gridcoin users BOINC reward

The previous attack through deobfuscation allows us to retrieve iCPID values and email addresses. Thus, we have all values needed to create a new legitimate eCPID. This is required because the CPIDv2 contains the last block hash and requires a re-computation for every new block it should be used in. We use this fact in the following attack and show how to steal the computational work from another legitimate Gridcoin Researcher by mining a new Gridcoin block with forged BOINC information. Throughout this last part of the post, we assume the Gridcoin Minter attacker model where the attacker has a valid Gridcoin account and can create new blocks. However, the attacker does not perform any BOINC work.

 Tab. 1: BOINCHash structure as stored and used in the Gridcoin blockchain.
As stated at the beginning of the blog post, the pre-image of the eCPID is stored obfuscated in every Gridcoin block, which contains a Proof-of-Research reward. We gathered one pre-image from the minted blocks of our victim and deobfuscated it. Thus, we know the values of the iCPID, and the email address of our victim. Subsequently, use the hash of the last block created by the network and use these three values to create a valid CPIDv2. Afterwards we constructed a new block. In the block we also store the current BOINC values of our victim, which we can gather from the statistics websites. The final block is afterwards sent into the Gridcoin network. In case all values are computed correctly by the attacker, the network will accept the block, and resulting in a higher reward for the attacker, consisting of Proof-of-Stake and Proof-of-Research reward.



 Fig. 4: Obfuscation function  Fig. 5: Deobfuscation function

Evaluation

In order to verify our attacks practically, we created two virtual machines (R and A), both running Ubuntu 14.04.3 LTS. The virtual machine R contained a legitimate BOINC and Gridcoin instance. It represented the setup of a normal Gridcoin Researcher. The second machine A contained a modified Gridcoin-Research client 3.5.6.8 version, which tried to steal the Proof-of-Research reward of virtual machine R. Thus, we did not steal reward of other legitimate users. The victim BOINC client was attached to the SETI@home project 11 with the eCPID 9f502770e61fc03d23d8e51adf7c6291.
The victim and the attacker were in possession of Gridcoins, enabling them to stake currency and to create new blocks.
 Fig. 6: CPIDv2 calculation deobfuscated

Initially both Gridcoin-Research clients retrieved the blockchain from other Gridcoin nodes in the Gridcoin network.
The Gridcoin attack client made it possible to specify the victim email address, iCPID and target project. All these values can be retrieved from the downloaded blockchain and our previous attack via the reverseCPIDv2 function as shown in Figure 7. The attack client read the iCPID and email address of the victim from a modified configuration file. All other values, for example, RAC or ResearchAge, were pulled from http://cpid.gridcoin.us:5000/get_user.php?cpid=. As soon as all values were received, the client attempted to create a new valid block.


 Fig. 7: Reverse the CPIDv2 calculation to get iCPID and email address

Once a block had been created and confirmed, the attacker received the increased coin reward with zero BOINC contribution done. The attack could only be detected by its victims because an outside user did not know the legitimate Gridcoin addresses a Researcher uses.
All blocks created with our victim's eCPID are shown in Table 2. Illegitimate blocks are highlighted. We were able to mint multiple illegitimate blocks, and thus stealing Research Age from our victim machine R. All nine blocks created and send by our attacker to the Gridcoin network passed the Gridcoin block verification, were confirmed multiple times, and are part of the current Gridcoin blockchain. During our testing timespan of approximately three weeks, the attacker machine was wrongfully rewarded with 72.4 Proof-of-Research generated Gridcoins, without any BOINC work. The results show that the attack is not only theoretically possible, but also very practical, feasible and effective. The attack results can be reproduced with our Gridcoin-Research-Attack client.

 Tab. 2:Blocks minted with the victim's eCPID

The Fix

In order to fix the security issue, we found one solution which does not require any changes to the BOINC source code nor the infrastructure. It is sufficient to change some parts of the already existing Gridcoin Beacon system. Thus, our solution is backwards compatible.
The current Gridcoin client utilizes so called Beacons to register new eCPIDs and stores them as a transaction of 0.0001 Gridcoins in a Superblock which is created every 24 hours. A Beacon encloses the user's personal eCPIDs, a corresponding unused (but irreversible) CPIDv2, and the wallet's main Gridcoin payment address. Once the Superblock is created, the eCPIDs is bound to one Gridcoin payment address. During the block verification process this bond is unfortunately not checked. Furthermore, the existing Beacon system does not use any strong asymmetric cryptography to ensure authenticity and integrity of the broadcasted data. We propose to extend the Beacon system with public key cryptography. In detail, we suggest that a user binds his fresh public key PK_1 to a newly generated eCPID, and then storing them together in a Superblock. An initial Beacon would therefore contain a hashed (e.g. SHA-256) eCPID, the public key, a Nonce, and a cryptographic signature created with the corresponding secret key SK_1 of the public key. This allows only the owner of the secret key to create valid signatures over blocks created with his eCPID. Thus, an adversary first needs to forge a cryptographic signature before he can claim Proof-of-Research work of another Gridcoin user. Thus, he is not capable of stealing the reward of the user.

Beacon to create a eCPID, public/secret key pair bond

For verification purposes nodes fetch the corresponding latest public key from one of the Superblocks. Furthermore, this Beacon structure allows a user to replace his previous public key associated with his eCPID. This is realized by submitting a new Beacon with a new public key PK_2, signed with his old secret key.

Beacon to update a eCPID, public/secret key pair bond

All Beacons in the chain are verifiable and the latest public key is always authentic. The Nonce provide freshness for the signature input, and therefore prevent replay attacks against the Beacon system.
Note that the eCPID needs to be completely unknown to the network, when sending the initial Beacon, for this concept to work as intended. The hash function ensures, that the Beacon does not reveal the fresh eCPID. As a result, an attacker is unable to mint with a eCPID even if he was able to intercept an initial Beacon and replaced the public key and signature with his own parameters, beforehand. This solution does not require any changes in the BOINC source code or the project servers.

Sign a block

In order to claim the Proof-of-Research reward for a newly created block, the Gridcoin minter computes a signature over the hash of the blockheader. Afterwards, he stores the resulting value at the end of the corresponding block in a new field. The private key used for the signature generation must correspond to the advertised public key by the user. It is important to note that the signature value is not part of the Merkle tree, and thus does not change the blockheader. In the end, the signature can then be verified by every other Gridcoin user via the advertised public key corresponding to the eCPID of the Gridcoin minter.

Responsible Disclosure

The attacks and the countermeasures were responsibly disclosed to the Gridcoin developer on the 14th of September, 2016. The developer used our proposed countermeasures and started to implement a new version. Since version 3.5.8.8, which is mandatory for all Gridcoin users, there exists an implementation, which contains countermeasures to our reward stealing attack.
See our next blog post, why Gridcoin is still insecure and should not be used anymore.

Further Reading
A more detailed description of Gridcoin and the attacks will be presented at WOOT'17, the paper is available here.

Authors

Tobias Niemann
Juraj Somorovsky
Related links