MeshCentral/rdp/asn1/spec.js
2022-04-29 11:13:58 -07:00

140 lines
2.9 KiB
JavaScript

/*
* Copyright (c) 2014-2015 Sylvain Peyrefitte
*
* This file is part of node-rdpjs.
*
* node-rdpjs is free software: you can redistribute it and/or modify
* it under the terms of the GNU 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
var inherits = require('util').inherits;
var type = require('../core').type;
var error = require('../core').error;
/**
* Tag Class
*/
var TagClass = {
Universal : 0x00,
Application : 0x40,
Context : 0x80,
Private : 0xC0
};
/**
* Tag Format
*/
var TagFormat = {
Primitive : 0x00,
Constructed : 0x20
};
/**
* ASN.1 tag
* @param tagClass {TagClass}
* @param tagFormat {TagFormat}
* @param tagNumber {integer}
*/
function Asn1Tag(tagClass, tagFormat, tagNumber) {
this.tagClass = tagClass;
this.tagFormat = tagFormat;
this.tagNumber = tagNumber;
}
/**
* ASN.1 Specification
* @param tag {Asn1Tag}
*/
function Asn1Spec(tag) {
this.tag = tag;
this.opt = false;
}
/**
* Add an implicit tag
* override tag
* @param tag {Asn1Tag}
* @returns {Asn1Spec}
*/
Asn1Spec.prototype.implicitTag = function(tag) {
this.tag = tag;
return this;
};
/**
* Set optional to true
* @returns {Asn1Spec}
*/
Asn1Spec.prototype.optional = function() {
this.opt = true;
return this;
};
/**
* Add explicit tag
* Append new tag header to existing tag
* @param tag {Asn1Tag}
* @returns {Asn1SpecExplicitTag}
*/
Asn1Spec.prototype.explicitTag = function(tag) {
return new Asn1SpecExplicitTag(tag, this);
};
/**
* Decode must be implemented by all sub type
* @param s {type.Stream}
* @param decoder
*/
Asn1Spec.prototype.decode = function(s, decoder) {
throw new error.FatalError('NODE_RDP_AS1_SPEC_DECODE_NOT_IMPLEMENTED');
};
/**
* Encode must be implemented by all sub type
* @param decoder
*/
Asn1Spec.prototype.encode = function(encoder) {
throw new error.FatalError('NODE_RDP_AS1_SPEC_ENCODE_NOT_IMPLEMENTED');
};
/**
* Component Asn1Spec object
*/
function Asn1SpecExplicitTag(tag, spec) {
Asn1Spec.call(this, tag);
this.spec = spec;
}
inherits(Asn1SpecExplicitTag, Asn1Spec);
/**
* Decode first header
* @param s {type.Stream}
* @param decoder
*/
Asn1Spec.prototype.decode = function(s, decoder) {
var specStream = new type.Stream(decoder.decode(s, this.tag).value);
this.spec.decode(specStream, decoder);
};
/**
* Module exports
*/
module.exports = {
TagClass : TagClass,
TagFormat : TagFormat,
Asn1Tag : Asn1Tag,
Asn1Spec : Asn1Spec,
Asn1SpecExplicitTag : Asn1SpecExplicitTag
};