@peculiar/asn1-x509

Parsing X.509 Certificates

This feature allows you to parse a raw X.509 certificate from a binary format (BER). The code sample demonstrates how to convert a base64-encoded certificate into a Certificate object.

const { Certificate } = require('@peculiar/asn1-x509');
const rawCert = Buffer.from('MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA1J...', 'base64');
const cert = Certificate.fromBER(rawCert);
console.log(cert);

Encoding X.509 Certificates

This feature allows you to encode an X.509 certificate into a binary format (BER). The code sample demonstrates how to create a Certificate object and convert it into a base64-encoded string.

const { Certificate } = require('@peculiar/asn1-x509');
const cert = new Certificate({
  tbsCertificate: {
    version: 2,
    serialNumber: new Uint8Array([1, 2, 3, 4]),
    signature: { algorithm: '1.2.840.113549.1.1.11' },
    issuer: { type: 'rdnSequence', value: [] },
    validity: { notBefore: new Date(), notAfter: new Date() },
    subject: { type: 'rdnSequence', value: [] },
    subjectPublicKeyInfo: { algorithm: { algorithm: '1.2.840.113549.1.1.1' }, subjectPublicKey: new Uint8Array([1, 2, 3, 4]) }
  },
  signatureAlgorithm: { algorithm: '1.2.840.113549.1.1.11' },
  signatureValue: new Uint8Array([1, 2, 3, 4])
});
const rawCert = cert.toSchema().toBER(false);
console.log(Buffer.from(rawCert).toString('base64'));

Manipulating Certificate Extensions

This feature allows you to manipulate extensions within an X.509 certificate. The code sample demonstrates how to add a new extension to a Certificate object.

const { Certificate, Extension } = require('@peculiar/asn1-x509');
const cert = new Certificate();
const ext = new Extension({
  extnID: '2.5.29.14',
  critical: false,
  extnValue: new Uint8Array([1, 2, 3, 4])
});
cert.tbsCertificate.extensions = [ext];
console.log(cert.tbsCertificate.extensions);