@bun-win32/crypt32

Zero-dependency, zero-overhead Win32 Crypt32 bindings for Bun on Windows.

Overview

@bun-win32/crypt32 exposes the crypt32.dll exports using Bun's FFI. It provides a single class, Crypt32, which lazily binds native symbols on first use. You can optionally preload a subset or all symbols up-front via Preload().

The bindings are strongly typed for a smooth DX in TypeScript.

Features

• Bun-first ergonomics on Windows 10/11.
• Direct FFI to crypt32.dll (certificate stores, certificate chains, encoding/decoding, data protection, signing, and more).
• In-source docs in structs/Crypt32.ts with links to Microsoft Docs.
• Lazy binding on first call; optional eager preload (Crypt32.Preload()).
• No wrapper overhead; calls map 1:1 to native APIs.
• Strongly-typed Win32 aliases (see types/Crypt32.ts).

Requirements

• Bun runtime
• Windows 10 or later

Installation

bun add @bun-win32/crypt32

Quick Start

import Crypt32 from '@bun-win32/crypt32';

// Open the current user's personal certificate store
const store = Crypt32.CertOpenSystemStoreW(0n, Buffer.from('MY\0', 'utf16le').ptr);

// Enumerate certificates
let cert = Crypt32.CertEnumCertificatesInStore(store, null);
let count = 0;
while (cert !== null) {
  count++;
  cert = Crypt32.CertEnumCertificatesInStore(store, cert);
}
console.log('Found %d certificates in MY store', count);

Crypt32.CertCloseStore(store, 0);

[!NOTE] AI agents: see AI.md for the package binding contract and source-navigation guidance. It explains how to use the package without scanning the entire implementation.

Examples

Run the included examples:

bun run example

Notes

• Either rely on lazy binding or call Crypt32.Preload().
• Windows only. Bun runtime required.
• SAL types & naming: nullability is in the type — Optional<T> (formally optional, SAL _*opt_) and Nullable<T> (plain [in]/[out] the docs say can be NULL), the null sentinel derived from T (null for pointers LP*/P*, 0n for handles/by-value addresses); direction is in the parameter name — _out (_Out_), _in_out (_Inout_), _In_ bare. See AI.md and the repo AGENTS.md.