1. Operating System in 1,000 Lines – Intro
Total comment counts : 25
Summary
The article outlines a book project aimed at guiding readers through the process of building a small operating system (OS) from scratch. It emphasizes that despite the complexity often associated with OS development, the core functions of an OS are fundamentally simple. Here are the key points:
Simplicity and Growth: The initial version of Linux was very small (8,413 lines), illustrating that OS development can start from a modest codebase.
Components to Build: The project will cover essential OS components like context switching, paging, user mode, a command-line interface, disk device drivers, and basic file operations, all implemented in approximately 1,000 lines of C code.
Challenges: The article highlights debugging as a significant challenge in OS development, especially since traditional debugging methods like
printfaren’t available until implemented. It promises to teach specialized debugging techniques for OS development.Learning Opportunity: The process, while tough, is portrayed as rewarding, offering a deep dive into the intricacies of how an OS operates.
The book aims to demystify OS development, making it accessible and exciting for hobbyists and learners, with an emphasis on practical learning through building and debugging an OS.
Top 1 Comment Summary
The article is about a book written by an author who aims to teach readers how to create an operating system (OS) from scratch over a weekend. The book suggests using any preferred programming language such as Rust or Zig, rather than sticking to traditional C. The OS described is intentionally non-UNIX-like, focusing only on essential components, which provides a creative and educational contrast to established systems like Linux or Windows. The author encourages readers to think innovatively about OS design. Additionally, some parts of the text might seem machine-translated, and the author invites contributions via pull requests, with the content hosted on GitHub in Markdown format.
Top 2 Comment Summary
The article suggests enhancing hobby OS development by setting up GDB debugging early in the process. The author shares their experience, noting that GDB debugging significantly improves upon using only the QEMU monitor for debugging. QEMU has an integrated GDB server, and to use it, one needs a GDB client compatible with the target architecture, such as RISC-V, and can connect to this server over a network. A link to further information on QEMU’s GDB setup is provided.
2. Cracking a 512-bit DKIM key for less than $8 in the cloud
Total comment counts : 25
Summary
The article discusses a study on the security of email authentication protocols (SPF, DKIM, DMARC) among the top 1 million websites, focusing particularly on DKIM keys. Here are the key points:
Discovery of Short Keys: Over 1,700 DKIM keys were found to be less than 1,024 bits, which are considered insecure and have been deprecated since 2018 by RFC 8301.
Cracking a Key: The researchers chose to crack a 512-bit RSA public key from redfin.com to demonstrate the vulnerability. They used Python to decode the key and then applied the Number Field Sieve (NFS) algorithm via the CADO-NFS tool to factorize the modulus into its prime factors, which took about 86 hours on a rented cloud server.
Testing the Compromised Key: After obtaining the private key, they set up a DKIM signature test, sending emails purporting to be from redfin.com. While most email providers rejected emails signed with this insecure key, three major services (Yahoo Mail, Mailfence, and Tuta) passed the DKIM check, allowing the emails to pass DMARC verification.
Security Implications: The experiment showed that even with current technology, breaking a 512-bit RSA key is feasible with minimal resources, highlighting the need for email providers to reject signatures from keys shorter than 1,024 bits.
Recommendations: The researchers urged domain owners to update their DKIM records to use keys of at least 1,024 bits and alerted email providers to reject short-key DKIM signatures. They also provided a simple method to check key length by counting characters in the Base64 encoded DKIM record.
Conclusion: The study underscores the ease with which outdated and insecure cryptographic practices can be exploited, advocating for stronger security measures in email authentication to prevent such vulnerabilities.
Top 1 Comment Summary
The article from 14 years ago, linked in the provided text, discusses how it was feasible back then to factorize 512-bit RSA keys, specifically referencing the DKIM (DomainKeys Identified Mail) RSA key used by Facebook at the time. The author of the blog post highlighted that even with the technology available in 2010, such keys could be broken, indicating concerns over the security of using relatively short key lengths for cryptographic purposes.
Top 2 Comment Summary
The article discusses an interesting scenario involving DKIM (DomainKeys Identified Mail) key sizes:
- The author suggests trying to use a 4096-bit DKIM key as an experiment.
- While setting up this key in DNS will pass all online checks for DKIM and SPF (Sender Policy Framework), any email sent using this key will fail validation tests.
- The reason for this failure is that although it’s valid to use keys larger than 2048 bits in DKIM, there is no requirement for email systems to process keys larger than this size.
- The author learned this the hard way, implying they experienced difficulties or unexpected outcomes when implementing this in practice.
3. Gate-level simulation of ASIC in browser
Total comment counts : 7
Summary
The article describes a demonstration of a gate-level simulation for Alexander Mordvintsev’s project submitted to TinyTapeout ‘09. This simulation runs in a web browser and showcases a circuit designed on a single tile of a multiproject chip. The circuit produces a 60fps VGA signal at 640x480 resolution, displaying a scrolling animation of various one-dimensional cellular automata rules. The tile contains two 160-bit shift registers: one for the current line of the image and another for preparing the next frame. The demo uses a custom WebAssembly simulator for the gate-level operations and includes an interactive visualization using SwissGL to show both the VGA screen content and the current processing ray’s position.
Top 1 Comment Summary
The article expresses admiration for the impressive technical skill required to fit a complex simulation into a small silicon space and run it in a web browser. However, the author also expresses doubt about their ability to achieve similar results with their project, the BitGrid.
Top 2 Comment Summary
The article linked in your text is actually a social media post on X (formerly Twitter) by the user “zzznah.” The post humorously compares the experience of running a design on real hardware to a video of a dog sliding uncontrollably across a wet floor. This metaphor likely illustrates the unpredictable and sometimes chaotic nature of testing designs in real-world conditions. However, without further context from the article or the post’s comments, the summary focuses on the humorous analogy presented.
4. A day in the life of a prolific voice phishing crew
Total comment counts : 15
Summary
The article details how voice phishing gangs exploit legitimate services from Apple and Google to scam users, focusing on a case where a cryptocurrency investor named Tony lost over $4.7 million. Here are the key points:
Initial Contact: Scammers initially contacted Tony via Google Assistant and used Google services to send deceptive emails and account recovery prompts.
Apple’s Role: Scammers are now using Apple’s support line to generate “account confirmation” messages, deceiving users into believing the communication is legitimate.
Crypto Chameleon: A prolific phishing group known for targeting high-profile entities like the FCC, Coinbase, and Binance, using a new phishing kit mimicking authentication providers like Okta.
Cybercrime Community: The phishing operations are run by figures like “Perm” and “Stotle” within the Star Fraud community on Telegram, where they develop and share voice phishing tactics.
Phishing Process: The scammers operate in teams with specific roles:
- The Caller: Engages in social engineering over the phone.
- The Operator: Manages the phishing panel, guiding the victim through fake websites.
- The Drainer: Accesses compromised accounts to steal funds.
- The Owner: Oversees the operation and takes a cut of the profits.
Example Attack: An example provided involves a musician in California where the scammers used Apple’s system to send multiple notifications and a fake Apple support call to manipulate the victim.
This article sheds light on the sophisticated methods used by phishing gangs to exploit trust in major tech companies, highlighting the need for vigilance among users of these platforms.
Top 1 Comment Summary
The article discusses a voice phishing scam targeting a small, independent gas station in rural Ohio. Scammers impersonated the gas station, leaving voice messages for numerous individuals, requesting payment for supposed unpaid bills via credit card over the phone. The scam used a fake call-back number. The author reflects on the potential for such scams to become automated with current technology like voice assistants and AI, predicting an increase in similar scams as the necessary tools become more accessible. The author finds the technical challenge of automating such a scam intriguing, though he wouldn’t engage in it himself, noting that others might not share his ethical reservations.
Top 2 Comment Summary
The article discusses several key points:
Crypto Accounts as Prime Targets: Criminals prefer targeting individuals with cryptocurrency accounts because these are perceived as easier to steal from compared to traditional banking systems. An example given is the theft from Mark Cuban, which only amounted to $40,000, indicating that even high-profile targets might not yield as much as expected.
Dynamics of Remote Criminal Teams: Remote teams of thieves scamming people over the phone tend to have a short lifespan due to internal theft among the members, contrasting with advice for bankers where remote work might reduce crime.
Domain Name Humor: The author expresses regret over not securing the domain “commandandcontrolserver.com”, suggesting it would have been a cool acquisition.
Security Measures for Traditional Banking: The article suggests that traditional banking should implement stricter measures like in-person visits for significant transactions to reduce fraud. It notes that the ease with which criminals can steal cryptocurrency shows where security should be tightened in conventional financial systems.
Overall, the piece highlights vulnerabilities in digital currencies and remote work setups among thieves, while advocating for stronger security in traditional banking to prevent similar exploitation.
5. Automated accessibility testing at Slack
Total comment counts : 13
Summary
Summary:
Slack prioritizes customer accessibility by adhering to its own Slack Accessibility Standards, which align with WCAG. The company employs a comprehensive strategy that includes:
- Manual Testing: Involving external testers and users with disabilities in the design and review process.
- Automated Testing: Slack introduced automated accessibility tests in 2022, focusing initially on desktop applications. They chose Axe for its compatibility and capabilities, integrating it into their testing frameworks.
Challenges with Integration:
- Jest and RTL: Attempts to integrate Axe with Jest and React Testing Library (RTL) were complicated by Slack’s custom Jest setup, leading them to pivot away from this approach.
- Playwright: They then focused on Playwright, an E2E testing framework, which supports Axe through the
@axe-core/playwrightpackage. The main issue here was the timing of accessibility checks due to Playwright’s Locator object, which ensures individual elements are ready rather than the entire page.
Solution:
- Slack decided to make concessions to simplify the developer workflow while using Playwright. They aimed to customize when and where accessibility checks would run, leveraging Axe Core’s features like exclusions and accessibility tags to manage the testing process more effectively. This approach allowed for more control and flexibility in their accessibility testing strategy.
Top 1 Comment Summary
The article discusses the author’s involvement with the axe accessibility testing engine, specifically mentioning how Slack has utilized and expanded upon this tool for their own needs. The axe-core engine and its integration with Playwright are open-sourced, but there’s also a commercial product, axe Developer Hub, which provides a workflow similar to what Slack has implemented. This involves integrating accessibility testing into existing end-to-end tests with minimal changes to the test suite. The author finds it enlightening to see which features Slack prioritized and how they’ve customized their setup with Playwright. Additionally, the author mentions that their team is currently hiring for roles focused on developing accessibility tools.
Top 2 Comment Summary
The article discusses the issue of accessibility in web content, particularly focusing on the use of images for code snippets. It highlights a concern with alt text for these images, noting that alt text often only provides a broad summary of the image content, which might not be sufficient for users relying on screen readers. This could pose a problem for accessibility, as detailed code might not be conveyed effectively through brief alt text descriptions.
6. Hyperview – Native mobile apps, as easy as creating a website
Total comment counts : 19
Summary
The article discusses Hyperview, a technology for mobile app development that uses Hyperview XML (HXML) instead of traditional HTML for rendering screens in mobile applications. Here are the key points:
Rendering: Hyperview apps fetch HXML content from a server to render screens, similar to how web browsers fetch HTML, but tailored for mobile interfaces.
Server-Side Control: Backend servers manage the app’s layout, content, and actions, allowing for updates to the app via server-side changes without needing app store submissions.
Technology Compatibility: It’s compatible with web technologies like Django, Rails, or Node.js, and can be hosted on any HTTP server or even as static XML files.
Benefits:
- Rapid Updates: Facilitates true Continuous Integration/Continuous Deployment (CI/CD) for mobile, reducing release cycles and app store review times.
- No Version Fragmentation: Users always run the latest version of the app, eliminating the need to support old versions.
Use Cases: Ideal for applications that rely heavily on network interactions like social networks, marketplaces, or media browsing. However, it’s not suited for apps needing extensive offline capabilities or local data processing.
Deployment: Offers flexibility in deployment, from traditional server setups to static file hosting.
Top 1 Comment Summary
The article discusses the process of reverse-engineering iOS system apps, highlighting how user interactions with the app store involve sending requests and receiving responses in an XML-like format that describe UI changes. An example given is an alert message for incorrect iTunes login credentials, showing how the response data is structured to mutate the UI accordingly.
Top 2 Comment Summary
The article discusses Hyperview, a mobile-oriented hypermedia system developed by Adam Stepinski. It’s highlighted as innovative, particularly because Stepinski created not just a concept but an entire hypermedia client and format. The system is further detailed in the third part of the book “Hypermedia Systems,” which can be accessed via a provided link. The author of the article considers Hyperview to be more groundbreaking than htmx, another hypermedia technology.
7. Servo Revival: 2023-2024
Total comment counts : 6
Summary
The article discusses the revival of the Servo project, an experimental web browser engine initially developed by Mozilla. Here are the key points:
Background: Servo was created in 2012 by Mozilla to showcase the capabilities of the Rust programming language, focusing on performance and security. After Mozilla disbanded its Servo team in 2020, the project saw little activity until Igalia took over its maintenance in January 2023 with external funding.
Igalia’s Involvement: Igalia has been instrumental in rejuvenating Servo, with a team of about five engineers working full-time. Their efforts include maintenance, community governance, and development. Servo has now joined Linux Foundation Europe to expand its reach and community.
Achievements: Under Igalia’s stewardship, there’s been an increase in project activity, evidenced by more merged pull requests, participation in programs like Outreachy, and financial support through platforms like GitHub Sponsors and Open Collective, raising over $24,500.
Community and Growth: The project has seen significant community engagement, particularly during contribution periods, which has helped in its growth and revival.
Challenges and Opportunities: While Servo has potential due to its unique attributes, it faces challenges like the need for broader funding and addressing technical complexities. Opportunities include potential adoption in specialized sectors like VR/AR and academic research.
Future Outlook: The future of Servo remains uncertain but promising, with a call for more contributors and sponsors to help sustain and advance the project.
The article ends with a hopeful note on the project’s future, encouraging interested parties to get involved or sponsor specific developments.
Top 1 Comment Summary
The article discusses a positive update about Servo, a project that has recently started accepting donations through Open Collective and GitHub Sponsors. The author expresses pleasure in learning about this development and their willingness to contribute financially.
Top 2 Comment Summary
The article you’ve linked to is a post on Bluesky, where Igalia claims to be the second biggest contributor to the Chromium project, following Google. However, since the link provided leads to a social media post rather than an article, there isn’t additional context or details in the given text about the specifics of their contributions or the basis of their claim.
8. Learning Synths
Total comment counts : 14
Summary
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Top 1 Comment Summary
The article suggests that to learn about subtractive synthesis, one should use VCV Rack, an open-source software. Here’s a summary:
- Understanding Subtractive Synthesis: The best approach is to download VCV Rack and follow some tutorials. By patching one subtractive mono synth voice, you’ll grasp about 80% of subtractive synthesis concepts.
- Resources:
- A link to VCV Rack’s website is provided for downloading the software.
- A YouTube tutorial is recommended for beginners to start with.
- Exploring Other Synthesis Types: The article also mentions that VCV Rack can be used to explore various other synthesis techniques like:
- Frequency/phase modulation synthesis
- Vector synthesis
- Physical modeling/Karplus-Strong synthesis
- Additive synthesis
- Eastcoast (subtractive) and Westcoast (waveshaping/LP gates) synthesis
The author wishes the reader a happy patching experience.
Top 2 Comment Summary
The article lists four Hacker News posts related to synthesizers and sound creation:
“Getting Started Making Sounds” - Posted in May 2022 with 3 comments, this post likely discusses the basics of sound synthesis.
“Abletone Learning Synth” - Posted in May 2022, it garnered 63 comments. This might involve learning how to use Ableton Live for synthesizer programming.
“Synth Playground” - From March 2021 with 21 comments, suggesting an interactive or educational platform for experimenting with synthesizers.
“Learning Synths” - Posted in June 2019, this thread has the highest engagement with 172 comments, indicating a broad discussion on learning about synthesizers.
Each post provides resources or discussions on various aspects of synthesizer use, learning, and experimentation, reflecting the community’s interest in electronic music production.
9. How to Debounce a Contact (2014)
Total comment counts : 19
Summary
The article discusses the problem of switch bounce in electronic devices, detailing how mechanical switches can cause multiple signals to be sent when only one is intended due to the physical nature of their contacts. Here’s a summary:
Purpose: The author conducted experiments to understand and document the characteristics of switch bounce to improve debounce coding techniques.
Methodology: Various types of switches were tested using an Agilent MSO-X 3054A mixed-signal oscilloscope (MSO) which allowed observation of both analog and digital signals. This setup was chosen after initial plans to use a microcontroller (MSP430) proved inadequate for capturing very short bounce times.
Findings:
- Switches showed varied and sometimes unexpected bouncing behavior, with bounces as short as under 100 nanoseconds.
- These brief transitions, while not always captured by microcontrollers, can still cause issues when tied to interrupts in software debounce routines.
Implications:
- The article emphasizes the need for understanding the full scope of switch bounce to develop effective debounce solutions, either in hardware or software.
- It criticizes the common practice of relying on anecdotal evidence and calls for more empirical research into switch behavior.
Additional Notes:
- The article is divided into revisions, with updates added over the years, showing an evolution in the research and findings.
- There’s mention of external resources, like Trent Cleghorn’s code, added in a later revision.
- The author also touches on the practical implications of poor debouncing, using examples like TV remote controls and FM radio tuning.
Top 1 Comment Summary
The article discusses the challenges of dealing with electromagnetic interference (EMI) in industrial settings:
Steel Mill Experience: The author describes installing a system with Z80 processors and a PDP-11 computer in a steel mill where a massive motor, which reversed direction frequently, caused significant electrical noise. This noise was so disruptive that it required extensive signal conditioning and protection like optocoupling to prevent damage to electronic components.
Elevator Motor Issue: In another instance, an elevator motor’s operation caused “phantom keypresses” on a terminal’s capacitive keypad, even activating debug buttons that weren’t physically present on the production model. This led to unexpected behavior in the system.
Solutions Implemented: The solutions involved:
- Excluding debug code from production firmware to avoid unintended access to debug modes.
- Enhancing transient suppression hardware and debouncing firmware to manage and mitigate the effects of EMI.
These anecdotes highlight the importance of designing electronic systems with robust EMI protection in environments with high electrical noise.
Top 2 Comment Summary
The article discusses the author’s experience with debouncing switches for hobbyist electronic projects, particularly for CNC endstop switches and simple button interfaces for counters. After trying various suggested methods for debouncing that failed, the author found a successful solution:
- Switch Configuration: The switch is set to be pulled either high or low.
- Capacitor Use: A capacitor connected to ground helps in smoothing out the switch’s signal.
- Schmitt Trigger: The switch signal is then passed through a Schmitt trigger to clean up the signal, ensuring a clean transition between states.
The author implemented this solution on a custom PCB, which resolved all issues with signal integrity, resulting in perfect square wave outputs. This was confirmed by adding test points on the PCB for waveform analysis. The process highlighted how many ineffective suggestions the author had to bypass before arriving at this effective, simple hardware debounce technique.
10. Streets GL – 3D OpenStreetMap
Total comment counts : 21
Summary
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Top 1 Comment Summary
The article mentions a project called CubeTrek, which focuses on 3D terrain simulation specifically for GPS tracks used in activities like hiking and skiing. The developer is currently working on this project, and provides a link to the project’s website and its open-source code repository on GitHub.
Top 2 Comment Summary
The article discusses a project which is visually appealing but is hindered by outdated OpenStreetMap (OSM) data, being over a year old. There is also a suggestion that the project might be abandoned, based on a related issue on GitHub.