149 lines
3.8 KiB
JavaScript
149 lines
3.8 KiB
JavaScript
// Copyright 2015 Joyent, Inc.
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module.exports = SSHBuffer;
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var assert = require('assert-plus');
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var Buffer = require('safer-buffer').Buffer;
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function SSHBuffer(opts) {
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assert.object(opts, 'options');
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if (opts.buffer !== undefined)
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assert.buffer(opts.buffer, 'options.buffer');
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this._size = opts.buffer ? opts.buffer.length : 1024;
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this._buffer = opts.buffer || Buffer.alloc(this._size);
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this._offset = 0;
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}
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SSHBuffer.prototype.toBuffer = function () {
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return (this._buffer.slice(0, this._offset));
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};
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SSHBuffer.prototype.atEnd = function () {
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return (this._offset >= this._buffer.length);
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};
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SSHBuffer.prototype.remainder = function () {
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return (this._buffer.slice(this._offset));
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};
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SSHBuffer.prototype.skip = function (n) {
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this._offset += n;
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};
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SSHBuffer.prototype.expand = function () {
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this._size *= 2;
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var buf = Buffer.alloc(this._size);
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this._buffer.copy(buf, 0);
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this._buffer = buf;
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};
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SSHBuffer.prototype.readPart = function () {
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return ({data: this.readBuffer()});
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};
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SSHBuffer.prototype.readBuffer = function () {
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var len = this._buffer.readUInt32BE(this._offset);
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this._offset += 4;
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assert.ok(this._offset + len <= this._buffer.length,
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'length out of bounds at +0x' + this._offset.toString(16) +
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' (data truncated?)');
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var buf = this._buffer.slice(this._offset, this._offset + len);
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this._offset += len;
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return (buf);
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};
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SSHBuffer.prototype.readString = function () {
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return (this.readBuffer().toString());
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};
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SSHBuffer.prototype.readCString = function () {
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var offset = this._offset;
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while (offset < this._buffer.length &&
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this._buffer[offset] !== 0x00)
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offset++;
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assert.ok(offset < this._buffer.length, 'c string does not terminate');
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var str = this._buffer.slice(this._offset, offset).toString();
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this._offset = offset + 1;
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return (str);
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};
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SSHBuffer.prototype.readInt = function () {
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var v = this._buffer.readUInt32BE(this._offset);
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this._offset += 4;
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return (v);
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};
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SSHBuffer.prototype.readInt64 = function () {
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assert.ok(this._offset + 8 < this._buffer.length,
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'buffer not long enough to read Int64');
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var v = this._buffer.slice(this._offset, this._offset + 8);
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this._offset += 8;
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return (v);
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};
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SSHBuffer.prototype.readChar = function () {
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var v = this._buffer[this._offset++];
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return (v);
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};
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SSHBuffer.prototype.writeBuffer = function (buf) {
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while (this._offset + 4 + buf.length > this._size)
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this.expand();
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this._buffer.writeUInt32BE(buf.length, this._offset);
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this._offset += 4;
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buf.copy(this._buffer, this._offset);
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this._offset += buf.length;
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};
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SSHBuffer.prototype.writeString = function (str) {
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this.writeBuffer(Buffer.from(str, 'utf8'));
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};
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SSHBuffer.prototype.writeCString = function (str) {
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while (this._offset + 1 + str.length > this._size)
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this.expand();
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this._buffer.write(str, this._offset);
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this._offset += str.length;
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this._buffer[this._offset++] = 0;
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};
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SSHBuffer.prototype.writeInt = function (v) {
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while (this._offset + 4 > this._size)
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this.expand();
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this._buffer.writeUInt32BE(v, this._offset);
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this._offset += 4;
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};
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SSHBuffer.prototype.writeInt64 = function (v) {
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assert.buffer(v, 'value');
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if (v.length > 8) {
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var lead = v.slice(0, v.length - 8);
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for (var i = 0; i < lead.length; ++i) {
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assert.strictEqual(lead[i], 0,
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'must fit in 64 bits of precision');
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}
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v = v.slice(v.length - 8, v.length);
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}
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while (this._offset + 8 > this._size)
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this.expand();
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v.copy(this._buffer, this._offset);
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this._offset += 8;
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};
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SSHBuffer.prototype.writeChar = function (v) {
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while (this._offset + 1 > this._size)
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this.expand();
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this._buffer[this._offset++] = v;
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};
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SSHBuffer.prototype.writePart = function (p) {
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this.writeBuffer(p.data);
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};
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SSHBuffer.prototype.write = function (buf) {
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while (this._offset + buf.length > this._size)
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this.expand();
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buf.copy(this._buffer, this._offset);
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this._offset += buf.length;
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};
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