@oslojs/asn1

A JavaScript library for encoding and decoding ASN.1 with Distinguished Encoding Rules (DER) by Oslo.

• Runtime-agnostic
• No third-party dependencies
• Fully typed

import { parseASN1NoLeftoverBytes } from "@oslojs/asn1";

const parsed = parseASN1NoLeftoverBytes(encoded);
const oid = parsed.sequence().at(0).objectIdentifier();
if (!oid.is("1.2.840.10045.4.3.2")) {
	throw new Error("Invalid OID");
}

This library only supports DER and not CER or BER.

Installation

npm i @oslojs/asn1