old-keypairs.js/lib/ec.js

'use strict';

var x509 = module.exports;

var ASN1 = require('./asn1-packer.js');
var Enc = require('./encoding.js');

// 1.2.840.10045.3.1.7
// prime256v1 (ANSI X9.62 named elliptic curve)
var OBJ_ID_EC_256  = '06 08 2A8648CE3D030107'.replace(/\s+/g, '').toLowerCase();
// 1.3.132.0.34
// secp384r1 (SECG (Certicom) named elliptic curve)
var OBJ_ID_EC_384 = '06 05 2B81040022'.replace(/\s+/g, '').toLowerCase();
// 1.2.840.10045.2.1
// ecPublicKey (ANSI X9.62 public key type)
var OBJ_ID_EC_PUB = '06 07 2A8648CE3D0201'.replace(/\s+/g, '').toLowerCase();

x509.packSec1 = function (jwk) {
  var d = Enc.base64ToHex(jwk.d);
  var x = Enc.base64ToHex(jwk.x);
  var y = Enc.base64ToHex(jwk.y);
  var objId = ('P-256' === jwk.crv) ? OBJ_ID_EC_256 : OBJ_ID_EC_384;
  return Enc.hexToUint8(
    ASN1('30'
    , ASN1.UInt('01')
    , ASN1('04', d)
    , ASN1('A0', objId)
    , ASN1('A1', ASN1.BitStr('04' + x + y)))
  );
};
x509.packPkcs8 = function (jwk) {
  var d = Enc.base64ToHex(jwk.d);
  var x = Enc.base64ToHex(jwk.x);
  var y = Enc.base64ToHex(jwk.y);
  var objId = ('P-256' === jwk.crv) ? OBJ_ID_EC_256 : OBJ_ID_EC_384;
  return Enc.hexToUint8(
    ASN1('30'
    , ASN1.UInt('00')
    , ASN1('30'
      , OBJ_ID_EC_PUB
      , objId
      )
    , ASN1('04'
      , ASN1('30'
        , ASN1.UInt('01')
        , ASN1('04', d)
        , ASN1('A1', ASN1.BitStr('04' + x + y)))))
  );
};
x509.packSpki = function (jwk) {
  var x = Enc.base64ToHex(jwk.x);
  var y = Enc.base64ToHex(jwk.y);
  var objId = ('P-256' === jwk.crv) ? OBJ_ID_EC_256 : OBJ_ID_EC_384;
  return Enc.hexToUint8(
    ASN1('30'
    , ASN1('30'
      , OBJ_ID_EC_PUB
      , objId
      )
    , ASN1.BitStr('04' + x + y))
  );
};
x509.packPkix = x509.packSpki;