--- /dev/null
+// Copyright 2011 Mark Cavage <mcavage@gmail.com> All rights reserved.
+
+var assert = require('assert');
+var ASN1 = require('./types');
+var errors = require('./errors');
+
+
+///--- Globals
+
+var newInvalidAsn1Error = errors.newInvalidAsn1Error;
+
+var DEFAULT_OPTS = {
+ size: 1024,
+ growthFactor: 8
+};
+
+
+///--- Helpers
+
+function merge(from, to) {
+ assert.ok(from);
+ assert.equal(typeof(from), 'object');
+ assert.ok(to);
+ assert.equal(typeof(to), 'object');
+
+ var keys = Object.getOwnPropertyNames(from);
+ keys.forEach(function(key) {
+ if (to[key])
+ return;
+
+ var value = Object.getOwnPropertyDescriptor(from, key);
+ Object.defineProperty(to, key, value);
+ });
+
+ return to;
+}
+
+
+
+///--- API
+
+function Writer(options) {
+ options = merge(DEFAULT_OPTS, options || {});
+
+ this._buf = new Buffer(options.size || 1024);
+ this._size = this._buf.length;
+ this._offset = 0;
+ this._options = options;
+
+ // A list of offsets in the buffer where we need to insert
+ // sequence tag/len pairs.
+ this._seq = [];
+}
+
+Object.defineProperty(Writer.prototype, 'buffer', {
+ get: function () {
+ if (this._seq.length)
+ throw new InvalidAsn1Error(this._seq.length + ' unended sequence(s)');
+
+ return (this._buf.slice(0, this._offset));
+ }
+});
+
+Writer.prototype.writeByte = function(b) {
+ if (typeof(b) !== 'number')
+ throw new TypeError('argument must be a Number');
+
+ this._ensure(1);
+ this._buf[this._offset++] = b;
+};
+
+
+Writer.prototype.writeInt = function(i, tag) {
+ if (typeof(i) !== 'number')
+ throw new TypeError('argument must be a Number');
+ if (typeof(tag) !== 'number')
+ tag = ASN1.Integer;
+
+ var sz = 4;
+
+ while ((((i & 0xff800000) === 0) || ((i & 0xff800000) === 0xff800000 >> 0)) &&
+ (sz > 1)) {
+ sz--;
+ i <<= 8;
+ }
+
+ if (sz > 4)
+ throw new InvalidAsn1Error('BER ints cannot be > 0xffffffff');
+
+ this._ensure(2 + sz);
+ this._buf[this._offset++] = tag;
+ this._buf[this._offset++] = sz;
+
+ while (sz-- > 0) {
+ this._buf[this._offset++] = ((i & 0xff000000) >>> 24);
+ i <<= 8;
+ }
+
+};
+
+
+Writer.prototype.writeNull = function() {
+ this.writeByte(ASN1.Null);
+ this.writeByte(0x00);
+};
+
+
+Writer.prototype.writeEnumeration = function(i, tag) {
+ if (typeof(i) !== 'number')
+ throw new TypeError('argument must be a Number');
+ if (typeof(tag) !== 'number')
+ tag = ASN1.Enumeration;
+
+ return this.writeInt(i, tag);
+};
+
+
+Writer.prototype.writeBoolean = function(b, tag) {
+ if (typeof(b) !== 'boolean')
+ throw new TypeError('argument must be a Boolean');
+ if (typeof(tag) !== 'number')
+ tag = ASN1.Boolean;
+
+ this._ensure(3);
+ this._buf[this._offset++] = tag;
+ this._buf[this._offset++] = 0x01;
+ this._buf[this._offset++] = b ? 0xff : 0x00;
+};
+
+
+Writer.prototype.writeString = function(s, tag) {
+ if (typeof(s) !== 'string')
+ throw new TypeError('argument must be a string (was: ' + typeof(s) + ')');
+ if (typeof(tag) !== 'number')
+ tag = ASN1.OctetString;
+
+ var len = Buffer.byteLength(s);
+ this.writeByte(tag);
+ this.writeLength(len);
+ if (len) {
+ this._ensure(len);
+ this._buf.write(s, this._offset);
+ this._offset += len;
+ }
+};
+
+
+Writer.prototype.writeBuffer = function(buf, tag) {
+ if (typeof(tag) !== 'number')
+ throw new TypeError('tag must be a number');
+ if (!Buffer.isBuffer(buf))
+ throw new TypeError('argument must be a buffer');
+
+ this.writeByte(tag);
+ this.writeLength(buf.length);
+ this._ensure(buf.length);
+ buf.copy(this._buf, this._offset, 0, buf.length);
+ this._offset += buf.length;
+};
+
+
+Writer.prototype.writeStringArray = function(strings) {
+ if ((!strings instanceof Array))
+ throw new TypeError('argument must be an Array[String]');
+
+ var self = this;
+ strings.forEach(function(s) {
+ self.writeString(s);
+ });
+};
+
+// This is really to solve DER cases, but whatever for now
+Writer.prototype.writeOID = function(s, tag) {
+ if (typeof(s) !== 'string')
+ throw new TypeError('argument must be a string');
+ if (typeof(tag) !== 'number')
+ tag = ASN1.OID;
+
+ if (!/^([0-9]+\.){3,}[0-9]+$/.test(s))
+ throw new Error('argument is not a valid OID string');
+
+ function encodeOctet(bytes, octet) {
+ if (octet < 128) {
+ bytes.push(octet);
+ } else if (octet < 16384) {
+ bytes.push((octet >>> 7) | 0x80);
+ bytes.push(octet & 0x7F);
+ } else if (octet < 2097152) {
+ bytes.push((octet >>> 14) | 0x80);
+ bytes.push(((octet >>> 7) | 0x80) & 0xFF);
+ bytes.push(octet & 0x7F);
+ } else if (octet < 268435456) {
+ bytes.push((octet >>> 21) | 0x80);
+ bytes.push(((octet >>> 14) | 0x80) & 0xFF);
+ bytes.push(((octet >>> 7) | 0x80) & 0xFF);
+ bytes.push(octet & 0x7F);
+ } else {
+ bytes.push(((octet >>> 28) | 0x80) & 0xFF);
+ bytes.push(((octet >>> 21) | 0x80) & 0xFF);
+ bytes.push(((octet >>> 14) | 0x80) & 0xFF);
+ bytes.push(((octet >>> 7) | 0x80) & 0xFF);
+ bytes.push(octet & 0x7F);
+ }
+ }
+
+ var tmp = s.split('.');
+ var bytes = [];
+ bytes.push(parseInt(tmp[0], 10) * 40 + parseInt(tmp[1], 10));
+ tmp.slice(2).forEach(function(b) {
+ encodeOctet(bytes, parseInt(b, 10));
+ });
+
+ var self = this;
+ this._ensure(2 + bytes.length);
+ this.writeByte(tag);
+ this.writeLength(bytes.length);
+ bytes.forEach(function(b) {
+ self.writeByte(b);
+ });
+};
+
+
+Writer.prototype.writeLength = function(len) {
+ if (typeof(len) !== 'number')
+ throw new TypeError('argument must be a Number');
+
+ this._ensure(4);
+
+ if (len <= 0x7f) {
+ this._buf[this._offset++] = len;
+ } else if (len <= 0xff) {
+ this._buf[this._offset++] = 0x81;
+ this._buf[this._offset++] = len;
+ } else if (len <= 0xffff) {
+ this._buf[this._offset++] = 0x82;
+ this._buf[this._offset++] = len >> 8;
+ this._buf[this._offset++] = len;
+ } else if (len <= 0xffffff) {
+ this._buf[this._offset++] = 0x83;
+ this._buf[this._offset++] = len >> 16;
+ this._buf[this._offset++] = len >> 8;
+ this._buf[this._offset++] = len;
+ } else {
+ throw new InvalidAsn1ERror('Length too long (> 4 bytes)');
+ }
+};
+
+Writer.prototype.startSequence = function(tag) {
+ if (typeof(tag) !== 'number')
+ tag = ASN1.Sequence | ASN1.Constructor;
+
+ this.writeByte(tag);
+ this._seq.push(this._offset);
+ this._ensure(3);
+ this._offset += 3;
+};
+
+
+Writer.prototype.endSequence = function() {
+ var seq = this._seq.pop();
+ var start = seq + 3;
+ var len = this._offset - start;
+
+ if (len <= 0x7f) {
+ this._shift(start, len, -2);
+ this._buf[seq] = len;
+ } else if (len <= 0xff) {
+ this._shift(start, len, -1);
+ this._buf[seq] = 0x81;
+ this._buf[seq + 1] = len;
+ } else if (len <= 0xffff) {
+ this._buf[seq] = 0x82;
+ this._buf[seq + 1] = len >> 8;
+ this._buf[seq + 2] = len;
+ } else if (len <= 0xffffff) {
+ this._shift(start, len, 1);
+ this._buf[seq] = 0x83;
+ this._buf[seq + 1] = len >> 16;
+ this._buf[seq + 2] = len >> 8;
+ this._buf[seq + 3] = len;
+ } else {
+ throw new InvalidAsn1Error('Sequence too long');
+ }
+};
+
+
+Writer.prototype._shift = function(start, len, shift) {
+ assert.ok(start !== undefined);
+ assert.ok(len !== undefined);
+ assert.ok(shift);
+
+ this._buf.copy(this._buf, start + shift, start, start + len);
+ this._offset += shift;
+};
+
+Writer.prototype._ensure = function(len) {
+ assert.ok(len);
+
+ if (this._size - this._offset < len) {
+ var sz = this._size * this._options.growthFactor;
+ if (sz - this._offset < len)
+ sz += len;
+
+ var buf = new Buffer(sz);
+
+ this._buf.copy(buf, 0, 0, this._offset);
+ this._buf = buf;
+ this._size = sz;
+ }
+};
+
+
+
+///--- Exported API
+
+module.exports = Writer;
Code Review / simantics / district.git / blobdiff