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    @peculiar/asn1-schema
    TypeScript icon, indicating that this package has built-in type declarations

    2.3.0 • Public • Published

    @peculiar/asn1-schema

    License npm version

    NPM

    This package uses ES2015 decorators to simplify working with ASN.1 creation and parsing.

    Introduction

    Abstract Syntax Notation One (ASN.1) is a standard interface description language for defining data structures that can be serialized and deserialized in a cross-platform way. Working with ASN.1 can be complicated as there are many ways to represent the same data and many solutions handcraft, incorrectly, the ASN.1 representation of the data.

    asn1-schema addresses this by using decorators to make both serialization and parsing of ASN.1 possible via a simple class that handles these problems for you.

    This is important because validating input data before its use is important to do because all input data is evil.

    Installation

    Installation is handled via npm:

    $ npm install @peculiar/asn1-schema
    

    TypeScript examples

    Node.js:

    ASN.1 schema

    Extension  ::=  SEQUENCE  {
      extnID      OBJECT IDENTIFIER,
      critical    BOOLEAN DEFAULT FALSE,
      extnValue   OCTET STRING
                  -- contains the DER encoding of an ASN.1 value
                  -- corresponding to the extension type identified
                  -- by extnID
    }
    
    id-ce-basicConstraints OBJECT IDENTIFIER ::=  { id-ce 19 }
    
    BasicConstraints ::= SEQUENCE {
      cA                      BOOLEAN DEFAULT FALSE,
      pathLenConstraint       INTEGER (0..MAX) OPTIONAL 
    }
    

    ASN.1 schema declaration in TypeScript project

    import { Asn1Prop, Asn1PropTypes, Asn1Serializer } from "@peculiar/asn1-schema";
    
    class Extension {
    
      public static CRITICAL = false;
    
      @AsnProp({ type: Asn1PropTypes.ObjectIdentifier })
      public extnID: string = "";
    
      @AsnProp({
        type: Asn1PropTypes.Boolean,
        defaultValue: Extension.CRITICAL,
      })
      public critical = Extension.CRITICAL;
    
      @AsnProp({ type: Asn1PropTypes.OctetString })
      public extnValue: ArrayBuffer = new ArrayBuffer(0);
    
    }
    
    class BasicConstraints {
      @AsnProp({ type: Asn1PropTypes.Boolean, defaultValue: false })
      public ca = false;
    
      @AsnProp({ type: Asn1PropTypes.Integer, optional: true })
      public pathLenConstraint?: number;
    }

    Encoding ASN.1 data

    const basicConstraints = new BasicConstraints();
    basicConstraints.ca = true;
    basicConstraints.pathLenConstraint = 1;
    
    const extension = new Extension();
    extension.critical = true;
    extension.extnID = "2.5.29.19";
    extension.extnValue = AsnSerializer.serialize(basicConstraints);
    
    console.log(Buffer.from(AsnSerializer.serialize(extension)).toString("hex")); // 30120603551d130101ff040830060101ff020101

    ASN.1 encoded data

    Decoding ASN.1 data

    const extension = AsnParser.parse(Buffer.from("30120603551d130101ff040830060101ff020101", "hex"), Extension);
    console.log("Extension ID:", extension.extnID); // Extension ID: 2.5.29.19
    console.log("Critical:", extension.critical); // Critical: true
    
    const basicConstraints = AsnParser.parse(extension.extnValue, BasicConstraints);
    console.log("CA:", basicConstraints.ca); // CA: true
    console.log("Path length:", basicConstraints.pathLenConstraint); // Path length: 1

    Install

    npm i @peculiar/asn1-schema

    DownloadsWeekly Downloads

    659,453

    Version

    2.3.0

    License

    MIT

    Unpacked Size

    156 kB

    Total Files

    57

    Last publish

    Collaborators

    • rmhrisk
    • microshine
    • yury.strozhevsky
    • peculiarventures
    • apilguk
    • donskov