ndn-js/js/browserify.js

A JavaScript client library for Named Data Networking

/**
 * Copyright (C) 2013-2019 Regents of the University of California.
 * @author: Wentao Shang
 *
 * This program 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 of the License, or
 * (at your option) any later version.
 *
 * This program 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 program.  If not, see <http://www.gnu.org/licenses/>.
 * A copy of the GNU Lesser General Public License is in the file COPYING.
 */

/** @ignore */
var ASN1HEX = require('../contrib/securityLib/asn1hex-1.1.js').ASN1HEX /** @ignore */
var KJUR = require('../contrib/securityLib/crypto-1.1.js').KJUR /** @ignore */
var RSAKey = require('../contrib/securityLib/rsasign-1.2.js').RSAKey /** @ignore */
var b64tohex = require('../contrib/securityLib/base64.js').b64tohex

// Library namespace
/** @ignore */
var ndn = ndn || {};

/** @ignore */
var exports = ndn;

// Factory method to create hasher objects
exports.createHash = function(alg)
{
  if (alg != 'sha256')
    throw new Error('createHash: unsupported algorithm.');

  var obj = {};

  obj.md = new KJUR.crypto.MessageDigest({alg: "sha256", prov: "cryptojs"});

  obj.update = function(buf) {
    this.md.updateHex(buf.toString('hex'));
  };

  obj.digest = function(encoding) {
    var hexDigest = this.md.digest();
    if (encoding == 'hex')
      return hexDigest;
    else if (encoding == 'base64')
      return new Buffer(hexDigest, 'hex').toString('base64');
    else
      return new Buffer(hexDigest, 'hex');
  };

  return obj;
};

// Factory method to create HMAC objects.
exports.createHmac = function(algorithm, key)
{
  if (algorithm !== 'sha256')
    throw new Error('createHmac: unsupported algorithm.');

  var obj = {};

  obj.md = new KJUR.crypto.Mac({alg: "HmacSHA256", pass: {hex: key.toString('hex')}});

  obj.update = function(buf) {
    this.md.updateHex(buf.toString('hex'));
  };

  obj.digest = function(encoding) {
    var hexDigest = this.md.doFinal();
    if (encoding == 'hex')
      return hexDigest;
    else if (encoding == 'base64')
      return new Buffer(hexDigest, 'hex').toString('base64');
    else
      return new Buffer(hexDigest, 'hex');
  };

  return obj;
};

// Factory method to create RSA signer objects
exports.createSign = function(alg)
{
  if (alg != 'RSA-SHA256')
    throw new Error('createSign: unsupported algorithm.');

  var obj = {};

  obj.arr = [];

  obj.update = function(buf) {
    this.arr.push(buf);
  };

  obj.sign = function(keypem) {
    var rsa = new RSAKey();
    rsa.readPrivateKeyFromPEMString(keypem);
    var signer = new KJUR.crypto.Signature({alg: "SHA256withRSA", prov: "cryptojs/jsrsa"});
    signer.initSign(rsa);
    for (var i = 0; i < this.arr.length; ++i)
      signer.updateHex(this.arr[i].toString('hex'));

    return new Buffer(signer.sign(), 'hex');
  };

  return obj;
};

// Factory method to create RSA verifier objects
exports.createVerify = function(alg)
{
  if (alg != 'RSA-SHA256')
    throw new Error('createSign: unsupported algorithm.');

  var obj = {};

  obj.arr = [];

  obj.update = function(buf) {
    this.arr.push(buf);
  };

  var getSubjectPublicKeyPosFromHex = function(hPub) {
    var a = ASN1HEX.getPosArrayOfChildren_AtObj(hPub, 0);
    if (a.length != 2)
      return -1;
    var pBitString = a[1];
    if (hPub.substring(pBitString, pBitString + 2) != '03')
      return -1;
    var pBitStringV = ASN1HEX.getStartPosOfV_AtObj(hPub, pBitString);
    if (hPub.substring(pBitStringV, pBitStringV + 2) != '00')
      return -1;
    return pBitStringV + 2;
  };

  var publicKeyPemToDer = function(publicKeyPem) {
    // Remove the '-----XXX-----' from the beginning and the end of the public
    // key and also remove any \n in the public key string.
    var lines = publicKeyPem.split('\n');
    var pub = "";
    for (var i = 1; i < lines.length - 1; i++)
      pub += lines[i];
    return new Buffer(pub, 'base64');
  }

  var readPublicDER = function(pub_der) {
    var hex = pub_der.toString('hex');
    var p = getSubjectPublicKeyPosFromHex(hex);
    var a = ASN1HEX.getPosArrayOfChildren_AtObj(hex, p);
    if (a.length != 2)
      return null;
    var hN = ASN1HEX.getHexOfV_AtObj(hex, a[0]);
    var hE = ASN1HEX.getHexOfV_AtObj(hex, a[1]);
    var rsaKey = new RSAKey();
    rsaKey.setPublic(hN, hE);
    return rsaKey;
  };

  obj.verify = function(keypem, sig) {
    var rsa = readPublicDER(publicKeyPemToDer(keypem));
    var signer = new KJUR.crypto.Signature({alg: "SHA256withRSA", prov: "cryptojs/jsrsa"});
    signer.initVerifyByPublicKey(rsa);
    for (var i = 0; i < this.arr.length; i++)
      signer.updateHex(this.arr[i].toString('hex'));
    var hSig = sig.toString('hex');
    return signer.verify(hSig);
  };

  return obj;
};

exports.randomBytes = function(size)
{
  // TODO: Use a cryptographic random number generator.
  var result = new Buffer(size);
  for (var i = 0; i < size; ++i)
    result[i] = Math.floor(Math.random() * 256);
  return result;
};

// contrib/feross/buffer.js needs base64.toByteArray. Define it here so that
// we don't have to include the entire base64 module.
exports.toByteArray = function(str) {
  var hex = b64tohex(str);
  var result = [];
  hex.replace(/(..)/g, function(ss) {
    result.push(parseInt(ss, 16));
  });
  return result;
};

module.exports = exports
// After this we include contrib/feross/buffer.js to define the Buffer class.