| 1 | /* |
| 2 | * Copyright (c) 2014-2015 Sylvain Peyrefitte |
| 3 | * |
| 4 | * This file is part of node-rdpjs. |
| 5 | * |
| 6 | * node-rdpjs is free software: you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation, either version 3 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License |
| 17 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 18 | */ |
| 19 | |
| 20 | var inherits = require('util').inherits; |
| 21 | var type = require('../core').type; |
| 22 | var error = require('../core').error; |
| 23 | |
| 24 | /** |
| 25 | * Tag Class |
| 26 | */ |
| 27 | var TagClass = { |
| 28 | Universal : 0x00, |
| 29 | Application : 0x40, |
| 30 | Context : 0x80, |
| 31 | Private : 0xC0 |
| 32 | }; |
| 33 | |
| 34 | /** |
| 35 | * Tag Format |
| 36 | */ |
| 37 | var TagFormat = { |
| 38 | Primitive : 0x00, |
| 39 | Constructed : 0x20 |
| 40 | }; |
| 41 | |
| 42 | /** |
| 43 | * ASN.1 tag |
| 44 | * @param tagClass {TagClass} |
| 45 | * @param tagFormat {TagFormat} |
| 46 | * @param tagNumber {integer} |
| 47 | */ |
| 48 | function Asn1Tag(tagClass, tagFormat, tagNumber) { |
| 49 | this.tagClass = tagClass; |
| 50 | this.tagFormat = tagFormat; |
| 51 | this.tagNumber = tagNumber; |
| 52 | } |
| 53 | |
| 54 | /** |
| 55 | * ASN.1 Specification |
| 56 | * @param tag {Asn1Tag} |
| 57 | */ |
| 58 | function Asn1Spec(tag) { |
| 59 | this.tag = tag; |
| 60 | this.opt = false; |
| 61 | } |
| 62 | |
| 63 | /** |
| 64 | * Add an implicit tag |
| 65 | * override tag |
| 66 | * @param tag {Asn1Tag} |
| 67 | * @returns {Asn1Spec} |
| 68 | */ |
| 69 | Asn1Spec.prototype.implicitTag = function(tag) { |
| 70 | this.tag = tag; |
| 71 | return this; |
| 72 | }; |
| 73 | |
| 74 | /** |
| 75 | * Set optional to true |
| 76 | * @returns {Asn1Spec} |
| 77 | */ |
| 78 | Asn1Spec.prototype.optional = function() { |
| 79 | this.opt = true; |
| 80 | return this; |
| 81 | }; |
| 82 | |
| 83 | /** |
| 84 | * Add explicit tag |
| 85 | * Append new tag header to existing tag |
| 86 | * @param tag {Asn1Tag} |
| 87 | * @returns {Asn1SpecExplicitTag} |
| 88 | */ |
| 89 | Asn1Spec.prototype.explicitTag = function(tag) { |
| 90 | return new Asn1SpecExplicitTag(tag, this); |
| 91 | }; |
| 92 | |
| 93 | /** |
| 94 | * Decode must be implemented by all sub type |
| 95 | * @param s {type.Stream} |
| 96 | * @param decoder |
| 97 | */ |
| 98 | Asn1Spec.prototype.decode = function(s, decoder) { |
| 99 | throw new error.FatalError('NODE_RDP_AS1_SPEC_DECODE_NOT_IMPLEMENTED'); |
| 100 | }; |
| 101 | |
| 102 | /** |
| 103 | * Encode must be implemented by all sub type |
| 104 | * @param decoder |
| 105 | */ |
| 106 | Asn1Spec.prototype.encode = function(encoder) { |
| 107 | throw new error.FatalError('NODE_RDP_AS1_SPEC_ENCODE_NOT_IMPLEMENTED'); |
| 108 | }; |
| 109 | |
| 110 | /** |
| 111 | * Component Asn1Spec object |
| 112 | */ |
| 113 | function Asn1SpecExplicitTag(tag, spec) { |
| 114 | Asn1Spec.call(this, tag); |
| 115 | this.spec = spec; |
| 116 | } |
| 117 | |
| 118 | inherits(Asn1SpecExplicitTag, Asn1Spec); |
| 119 | |
| 120 | /** |
| 121 | * Decode first header |
| 122 | * @param s {type.Stream} |
| 123 | * @param decoder |
| 124 | */ |
| 125 | Asn1Spec.prototype.decode = function(s, decoder) { |
| 126 | var specStream = new type.Stream(decoder.decode(s, this.tag).value); |
| 127 | this.spec.decode(specStream, decoder); |
| 128 | }; |
| 129 | |
| 130 | /** |
| 131 | * Module exports |
| 132 | */ |
| 133 | module.exports = { |
| 134 | TagClass : TagClass, |
| 135 | TagFormat : TagFormat, |
| 136 | Asn1Tag : Asn1Tag, |
| 137 | Asn1Spec : Asn1Spec, |
| 138 | Asn1SpecExplicitTag : Asn1SpecExplicitTag |
| 139 | }; |