tenvoy/openpgpjs/src/type/oid.js

PGP, NaCl, and PBKDF2 in node.js and the browser (hashing, random, encryption, decryption, signatures, conversions), used by TogaTech.org

// OpenPGP.js - An OpenPGP implementation in javascript
// Copyright (C) 2015-2016 Decentral
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 3.0 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

/**
 * Wrapper to an OID value
 *
 * {@link https://tools.ietf.org/html/rfc6637#section-11|RFC6637, section 11}:
 * The sequence of octets in the third column is the result of applying
 * the Distinguished Encoding Rules (DER) to the ASN.1 Object Identifier
 * with subsequent truncation.  The truncation removes the two fields of
 * encoded Object Identifier.  The first omitted field is one octet
 * representing the Object Identifier tag, and the second omitted field
 * is the length of the Object Identifier body.  For example, the
 * complete ASN.1 DER encoding for the NIST P-256 curve OID is "06 08 2A
 * 86 48 CE 3D 03 01 07", from which the first entry in the table above
 * is constructed by omitting the first two octets.  Only the truncated
 * sequence of octets is the valid representation of a curve OID.
 * @requires util
 * @requires enums
 * @module type/oid
 */

import util from '../util';
import enums from '../enums';

/**
 * @constructor
 */
function OID(oid) {
  if (oid instanceof OID) {
    this.oid = oid.oid;
  } else if (util.isArray(oid) ||
             util.isUint8Array(oid)) {
    oid = new Uint8Array(oid);
    if (oid[0] === 0x06) { // DER encoded oid byte array
      if (oid[1] !== oid.length - 2) {
        throw new Error('Length mismatch in DER encoded oid');
      }
      oid = oid.subarray(2);
    }
    this.oid = oid;
  } else {
    this.oid = '';
  }
}

/**
 * Method to read an OID object
 * @param  {Uint8Array}  input  Where to read the OID from
 * @returns {Number}             Number of read bytes
 */
OID.prototype.read = function (input) {
  if (input.length >= 1) {
    const length = input[0];
    if (input.length >= 1 + length) {
      this.oid = input.subarray(1, 1 + length);
      return 1 + this.oid.length;
    }
  }
  throw new Error('Invalid oid');
};

/**
 * Serialize an OID object
 * @returns {Uint8Array} Array with the serialized value the OID
 */
OID.prototype.write = function () {
  return util.concatUint8Array([new Uint8Array([this.oid.length]), this.oid]);
};

/**
 * Serialize an OID object as a hex string
 * @returns {string} String with the hex value of the OID
 */
OID.prototype.toHex = function() {
  return util.Uint8Array_to_hex(this.oid);
};

/**
 * If a known curve object identifier, return the canonical name of the curve
 * @returns {string} String with the canonical name of the curve
 */
OID.prototype.getName = function() {
  const hex = this.toHex();
  if (enums.curve[hex]) {
    return enums.write(enums.curve, hex);
  } else {
    throw new Error('Unknown curve object identifier.');
  }
};

OID.fromClone = function (clone) {
  return new OID(clone.oid);
};

export default OID;