お近づきになりたい人向けシリーズです。 いろいろなトピックを詰め込みましたが、「これら全部を知らないといけない」のようなつもりではなく、いろいろなことを知るきっかけになったらいいなという気持ちなので、あまり身構えずにちょっとずつ読んでもらえたらうれしい気がします。 まえがき 予備知識 規格 用語 精度という語について 記法 表現について 有限値の表現について エンコードについて 丸めについて よくある誤差や勘違いの例 0.1 = 1 / 10? 0.1 + 0.2 = 0.3? 整数の誤差 Rump’s Example 基本的な誤差評価 用語に関して 実数の丸め 有理数の丸め 基本演算の丸め 差について 複数回の演算 補題たち 桁落ちについて Re: Rump’s example 融合積和 数学関数に関する式の計算 誤差の削減に関して 総和計算 数学関数の精度について 比較演算について 雑
PostgreSQL Client から自作 DBMS に接続する - goropikariの備忘録
最近、Go の練習がてら書いていた自作 DBMS に PostgreSQL client で接続できるようになったので、そのやり方を残しておきます。(これから紹介するサンプルコードはすべて Python ですが) github.com psql --version psql (PostgreSQL) 13.2 pgcon の資料と PostgreSQL の公式 Document、加えて PostgreSQL server と client 間に流れるパケットを眺めると、自作DBMSは client から接続されたときにどういうパケットを返せばいいのかが見えてきます。 https://www.pgcon.org/2014/schedule/attachments/330_postgres-for-the-wire.pdf https://www.postgresql.org/docs/13/
Internet Engineering Task Force (IETF) K. Davis Request for Comments: 9562 Cisco Systems Obsoletes: 4122 B. Peabody Category: Standards Track Uncloud ISSN: 2070-1721 P. Leach University of Washington May 2024 Universally Unique IDentifiers (UUIDs) Abstract This specification defines UUIDs (Universally Unique IDentifiers) -- also known as GUIDs (Globally Unique IDentifiers) -- and a Uniform Resou
How to Bypass Cloudflare in 2023: The 8 Best Methods - ZenRows
About 1/5 of websites you need to scrape use Cloudflare, a hardcore anti-bot protection system that gets you blocked easily. So what can you do? 😥 We spent a million dollars figuring out how to bypass Cloudflare in 2023 so that you don't have to and wrote the most complete guide (you're reading it!). These are some of the techniques you'll get home today: Method 1: Get around Cloudflare CDN. Meth
World’s First MIDI Shellcode Jan 2025 · 45 min read I gained remote code execution via MIDI messages to trick my synth into playing Bad Apple on its LCD. This blog post is about my journey with this reverse engineering project. Final iteration of Bad Apple The beginning I’ve had this Yamaha PSR-E433 synth for a very long time, and a couple of years ago I decided to open it up — partly because it w
Tier 4 Support § Support for these targets is entirely experimental. If this target is provided by LLVM, LLVM may have the target as an experimental target, which means that you need to use Zig-provided binaries for the target to be available, or build LLVM from source with special configure flags. zig targets will display the target if it is available. This target may be considered deprecated by
KDL is a small, pleasing document language with xml-like semantics that looks like you're invoking a bunch of CLI commands! It's meant to be used both as a serialization format and a configuration language, much like JSON, YAML, or XML. It looks like this: package { name "my-pkg" version "1.2.3" dependencies { // Nodes can have standalone values as well as // key/value pairs. lodash "^3.2.1" optio
My thoughts on writing a Minecraft server from scratch (in Bash) For the past year or so, I've been thinking about writing a Minecraft server in Bash as a thought excercise. I once tried that before with the Classic protocol (the one from 2009), but I quickly realized there wasn't really a way to properly parse binary data in bash. Take the following code sample: function a() { read -n 2 uwu echo
Tier 4 Support § Support for these targets is entirely experimental. If this target is provided by LLVM, LLVM may have the target as an experimental target, which means that you need to use Zig-provided binaries for the target to be available, or build LLVM from source with special configure flags. zig targets will display the target if it is available. This target may be considered deprecated by
Hello friends, this is the first of two, possibly three (if and when I have time to finish the Windows research) writeups. We will start with targeting GNU/Linux systems with an RCE. As someone who’s directly involved in the CUPS project said: From a generic security point of view, a whole Linux system as it is nowadays is just an endless and hopeless mess of security holes waiting to be exploited
ヤフー株式会社は、2023年10月1日にLINEヤフー株式会社になりました。LINEヤフー株式会社の新しいブログはこちらです。LINEヤフー Tech Blog ヤフーの IaaS チームに所属する木下です。普段はインフラエンジニアとして IaaS 基盤の開発・構築・運用を担当しています。 ヤフーを傘下に持つZホールディングスは、高度化するサイバーセキュリティの脅威に対応するため、サイバーセキュリティ基本方針を掲げています。 この基本方針の中で、Zホールディングスおよびそのグループ企業は、米国標準技術研究所（NIST）が定めたサイバーセキュリティ基準に準拠したシステムを構築し、サービスを提供すると宣言しています。 タイトルにある NIST SP800-171 はこの「米国標準技術研究所（NIST）が定めたサイバーセキュリティ基準」の一例です。 私が担当する IaaS 基盤でも、このサイバー
Reading the excellent article by JeanHeyd Meneide on how broken string encoding in C/C++ is made me realise that Unicode is a topic that is often overlooked by a large number of developers. In my experience, there’s a lot of confusion and wrong expectations on what Unicode is, and what best practices to follow when dealing with strings that may contain characters outside of the ASCII range. This a
Try Mastering Emacs for free! Are you struggling with the basics? Have you mastered movement and editing yet? When you have read Mastering Emacs you will understand Emacs. It’s that time again: there’s a new major version of Emacs and, with it, a treasure trove of new features and changes. Notable features include the formal inclusion of native compilation, a technique that will greatly speed up y
Amazon FSx for NetApp ONTAPファイルシステム上のiSCSI LUNをマウントしてみた | DevelopersIO
Amazon FSx for NetApp ONTAPは単純なファイルサーバーじゃないぞ こんにちは、のんピ(@non____97)です。 皆さんはMulti-AZのEBSボリュームを欲しいなと思ったことはありますか? 私はあります。 EBSボリュームはAZ単位なのでAZ障害のことを考えるとちょっと心配です。かと言って自分でブロックレベルのレプリケーションを実装するのも何だか大変です。 そこで、Amazon FSx for NetApp ONTAPの出番です。 Amazon FSx for NetApp ONTAPはファイルサーバーとしての機能だけではなく、ブロックストレージとしての機能も有しています。 Q: Amazon FSx for NetApp ONTAP はどのプロトコルをサポートしていますか? A: Amazon FSx for NetApp ONTAP は、ネットワークファイ
In this write-up, I will walk you through an implementation of a string formatting library for C++ I came up with for my video game. The end result came out really compact, at only 65 lines of code—providing a skeleton that can be supplemented with additional functionality at low cost. Usage Given a format buffer… char buffer[64]; String_Buffer buf = {str, sizeof str}; …the fmt::format function pr
The feature is still under refinement, yet ready to use. Feedback is welcome. View the preview features (@tag:preview). Copilot Edits Agent mode improvements (Experimental) Last month, we introduced agent mode for Copilot Edits in VS Code Insiders. In agent mode, Copilot can automatically search your workspace for relevant context, edit files, check them for errors, and run terminal commands (with
Large Text Compression Benchmark Matt Mahoney Last update: July 3, 2025. history This competition ranks lossless data compression programs by the compressed size (including the size of the decompression program) of the first 109 bytes of the XML text dump of the English version of Wikipedia on Mar. 3, 2006. About the test data. The goal of this benchmark is not to find the best overall compressi
This December I once again did the Advent of Code, in Rust. If you are interested, my solutions are on Github. I wanted to highlight one particular solution to the day 2 problem as it is both optimized completely beyond the point of reason yet contains a useful technique. For simplicity we’re only going to do part 1 of the day 2 problem here, but the exact same techniques apply to part 2. We’re go
Node.js
Notable Changes Add fetch API Adds experimental support to the fetch API. This adds a --experimental-fetch flag that installs the fetch, Request, Response and Headers globals. [76a229c4ff] - (SEMVER-MINOR) lib: add fetch (Michaël Zasso) #41749 Add stream methods [1ae648567a] - (SEMVER-MINOR) stream: add iterator helper find (linkgoron) #41849 [62e1a68077] - (SEMVER-MINOR) stream: add toArray (Benj
redbean 2.0 release notes
redbean is a webserver in a zip executable that runs on six operating systems. The basic idea is if you want to build a web app that runs anywhere, then you download the redbean.com file, put your .html and .lua files inside it using the zip command, and then you've got a hermetic app you can deploy and share. I introduced this web server about a year ago on Hacker News, where it became the third
Flipping Pages: An analysis of a new Linux vulnerability in nf_tables and hardened exploitation techniques
This blogpost is the next instalment of my series of hands-on no-boilerplate vulnerability research blogposts, intended for time-travellers in the future who want to do Linux kernel vulnerability research. Specifically, I hope beginners will learn from my VR workflow and the seasoned researchers will learn from my techniques. In this blogpost, I'm discussing a bug I found in nf_tables in the Linux
I find blockchain fascinating because it extends open source software development to open source + state. This seems to be a genuine/exciting innovation in computing paradigms; We don’t just get to share code, we get to share a running computer, and anyone anywhere can use it in an open and permissionless manner. The seeds of this revolution arguably began with Bitcoin, so I became curious to dril
IDAPythonによる解析の自動化をやってみる 逆アセンブラ，デコンパイラのデファクトスタンダードなツールの一つにIDA Proがある．IDA ProはPythonを使ったスクリプティング機能を提供しており，この機能を使うことでプラグインといった形でIDA自身の機能を拡張したり，面倒な手動解析を自動化することができる．このエントリでは，マルウェア解析を例としてIDAPythonを使った解析工程の一部の自動化をやってみる． シナリオ マルウェア作者は悪意あるコード部分で使用するAPIを動的にインポートすることで，静的解析のハードルを上げようと試みることがある．つまり実行の初期の段階でグローバルな変数にAPIのアドレスを保存しておき，API使用時には関数ポインタとしてこれを呼び出す．こうすることにより静的解析を行う解析者からはcall命令でデータ領域のある値へジャンプするように見え，一見して
Rust vs C++ Formatting
In Rust, if I want to print some 32-bit unsigned value in hex, with the leading 0x, padded out with zeros, I would write that as: println!("{:#010x}", value); In C++23, if I want to do the same, that’s: std::println("{:#010x}", value); The only difference is the spelling of the name of the thing we’re calling (which is a function template in C++ and a macro in Rust) - otherwise, identical. Neverth
Introduction: These Aren’t the JSONs You’re Looking For JSON (JavaScript Object Notation) was designed as a simple, lightweight, and human-readable data interchange format, often positioned as a more accessible alternative to XML. It has become the de facto standard for web APIs and system integration. However, while the specification itself is straightforward, different programming languages and
OffSec社のEXP-301コースを受講し、OSED試験に合格できました。コースや試験の概要、これから取り組む方へのアドバイス、備忘録等の記事です。 なお、レポート作成方法はPEN-200-2022受講記 & OSCP合格記の時とほぼ同じです。よろしければそちらの記事もご参照ください。 分かる人向けの結果概要 EXP-301コースとは サポート関係 IDAの逆コンパイル機能は使えないので注意 Lab環境のWinDbgバージョンが古くて一部辛い 私の事前知識 EXP-301コース受講記 OSED試験受験記 OSED試験の申込み 試験の準備 OSED試験本番 合格通知 感想 おまけ: 検証用コードの紹介 bad Characters確認用コード ROPチェーン構築用クラス 分かる人向けの結果概要 EXP-301コース関連に合計210時間ほど取り組みました。 ExerciseやExtra Mi
Update 1.88.1: The update addresses these issues. Downloads: Windows: x64 Arm64 | Mac: Universal Intel silicon | Linux: deb rpm tarball Arm snap Welcome to the March 2024 release of Visual Studio Code. There are many updates in this version that we hope you'll like, some of the key highlights include: Apply custom editor labels - Distinguish between editors with same file names. Locked scrolling -
Workshop: An Introduction to macOS Forensics with Open Source Software
Workshop: An Introduction to macOS Forensics with Open Source Software Japan Security Analyst Conference 2022 株式会社インターネットイニシアティブ 小林 稔 Who am I? 小林 稔 2 • 株式会社インターネットイニシアティブ セキュリティ本部 セキュリティ情報統括室 技術調査、社内インシデントレスポンス • 外部活動 セキュリティキャンプ全国大会講師 2017-2019 Japan Security Analyst Conference Speaker 2018/2020 Black Hat USA 2018 Briefing Speaker • Twitter: @unkn0wnbit はじめに 3 0 本ワークショップの目的 (1/2) ◦本ワークショップでやること ▪
Join a VS Code Dev Days event near you to learn about AI-assisted development in VS Code. Release date: September 11, 2025 Update 1.104.1: The update addresses these issues. Update 1.104.2: The update addresses these issues. Downloads: Windows: x64 Arm64 | Mac: Universal Intel silicon | Linux: deb rpm tarball Arm snap Welcome to the August 2025 release of Visual Studio Code. There are many updates
GitHub - ComfyUI-Workflow/awesome-comfyui: A collection of awesome custom nodes for ComfyUI
ComfyUI-Gemini_Flash_2.0_Exp (⭐+172): A ComfyUI custom node that integrates Google's Gemini Flash 2.0 Experimental model, enabling multimodal analysis of text, images, video frames, and audio directly within ComfyUI workflows. ComfyUI-ACE_Plus (⭐+115): Custom nodes for various visual generation and editing tasks using ACE_Plus FFT Model. ComfyUI-Manager (⭐+113): ComfyUI-Manager itself is also a cu
Xortigate, or CVE-2023-27997 - The Rumoured RCE That Was
When Lexfo Security teased a critical pre-authentication RCE bug in FortiGate devices on Saturday 10th, many people speculated on the practical impact of the bug. Would this be a true, sky-is-falling level vulnerability like the recent CVE-2022-42475? Or was it some edge-case hole, requiring some unusual and exotic requisite before any exposure? Others even went further, questioning the legitimacy
Update 1.89.1: The update addresses these issues. Downloads: Windows: x64 Arm64 | Mac: Universal Intel silicon | Linux: deb rpm tarball Arm snap Welcome to the April 2024 release of Visual Studio Code. There are many updates in this version that we hope you'll like, some of the key highlights include: Preview Markdown images & videos - Hover over a link to preview images & videos in Markdown. Enha
j次のブックマーク
k前のブックマーク
lあとで読む
eコメント一覧を開く
oページを開く
浮動小数点型の算術とお近づきになりたい人向けの記事 - えびちゃんの日記
RFC 9562: Universally Unique IDentifiers (UUIDs)
World's First MIDI Shellcode
0.8.0 Release Notes ⚡ The Zig Programming Language
The KDL Document Language
My thoughts on writing a Minecraft server from scratch (in Bash)
0.10.0 Release Notes ⚡ The Zig Programming Language
Attacking UNIX Systems via CUPS, Part I
NIST SP800-171へ準拠することが決まったら 〜 FIPSモードを有効化した場合
Unicode is harder than you think · mcilloni's blog
What's New in Emacs 28.1?
A string formatting library in 65 lines of C++
February 2025 (version 1.98)
Large Text Compression Benchmark
The World's Smallest Hash Table | orlp.net
A from-scratch tour of Bitcoin in Python
IDAPythonによる解析の自動化をやってみる(静的解析編) - Snoozy
JSON is not JSON Across Languages | Dochia CLI Blog
EXP-301受講記 & OSED合格記 - プログラム系統備忘録ブログ
March 2024 (version 1.88)
August 2025 (version 1.104)
April 2024 (version 1.89)