/**
* Copyright (C) 2014-2016 Regents of the University of California.
* @author: Jeff Thompson <jefft0@remap.ucla.edu>
*
* 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.
*/
// Use capitalized Crypto to not clash with the browser's crypto.subtle.
/** @ignore */
var Crypto = require('../crypto.js'); /** @ignore */
var WireFormat = require('../encoding/wire-format.js').WireFormat; /** @ignore */
var TlvEncoder = require('../encoding/tlv/tlv-encoder.js').TlvEncoder; /** @ignore */
var Blob = require('./blob.js').Blob;
/**
* A CommandInterestGenerator keeps track of a timestamp and generates command
* interests according to the NFD Signed Command Interests protocol:
* http://redmine.named-data.net/projects/nfd/wiki/Command_Interests
*
* Create a new CommandInterestGenerator and initialize the timestamp to now.
* @constructor
*/
var CommandInterestGenerator = function CommandInterestGenerator()
{
this.lastTimestamp = Math.round(new Date().getTime());
};
exports.CommandInterestGenerator = CommandInterestGenerator;
/**
* Append a timestamp component and a random value component to interest's name.
* This ensures that the timestamp is greater than the timestamp used in the
* previous call. Then use keyChain to sign the interest which appends a
* SignatureInfo component and a component with the signature bits. If the
* interest lifetime is not set, this sets it.
* @param {Interest} interest The interest whose name is append with components.
* @param {KeyChain} keyChain The KeyChain for calling sign.
* @param {Name} certificateName The certificate name of the key to use for
* signing.
* @param {WireFormat} wireFormat (optional) A WireFormat object used to encode
* the SignatureInfo and to encode interest name for signing. If omitted, use
* WireFormat.getDefaultWireFormat().
* @param {function} onComplete (optional) This calls onComplete() when complete.
* (Some crypto/database libraries only use a callback, so onComplete is
* required to use these.)
*/
CommandInterestGenerator.prototype.generate = function
(interest, keyChain, certificateName, wireFormat, onComplete)
{
onComplete = (typeof wireFormat === "function") ? wireFormat : onComplete;
wireFormat = (typeof wireFormat === "function" || !wireFormat) ?
WireFormat.getDefaultWireFormat() : wireFormat;
var timestamp = Math.round(new Date().getTime());
while (timestamp <= this.lastTimestamp)
timestamp += 1.0;
// The timestamp is encoded as a TLV nonNegativeInteger.
var encoder = new TlvEncoder(8);
encoder.writeNonNegativeInteger(timestamp);
interest.getName().append(new Blob(encoder.getOutput(), false));
// The random value is a TLV nonNegativeInteger too, but we know it is 8
// bytes, so we don't need to call the nonNegativeInteger encoder.
interest.getName().append(new Blob(Crypto.randomBytes(8), false));
// Update the timestamp before calling async sign.
this.lastTimestamp = timestamp;
keyChain.sign(interest, certificateName, wireFormat, function() {
if (interest.getInterestLifetimeMilliseconds() == null ||
interest.getInterestLifetimeMilliseconds() < 0)
// The caller has not set the interest lifetime, so set it here.
interest.setInterestLifetimeMilliseconds(1000.0);
if (onComplete)
onComplete();
});
};