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