CasperSecurity
'use strict';
/* eslint camelcase: "off" */
var assert = require('assert');
var Zstream = require('pako/lib/zlib/zstream');
var zlib_deflate = require('pako/lib/zlib/deflate.js');
var zlib_inflate = require('pako/lib/zlib/inflate.js');
var constants = require('pako/lib/zlib/constants');
for (var key in constants) {
exports[key] = constants[key];
}
// zlib modes
exports.NONE = 0;
exports.DEFLATE = 1;
exports.INFLATE = 2;
exports.GZIP = 3;
exports.GUNZIP = 4;
exports.DEFLATERAW = 5;
exports.INFLATERAW = 6;
exports.UNZIP = 7;
var GZIP_HEADER_ID1 = 0x1f;
var GZIP_HEADER_ID2 = 0x8b;
/**
* Emulate Node's zlib C++ layer for use by the JS layer in index.js
*/
function Zlib(mode) {
if (typeof mode !== 'number' || mode < exports.DEFLATE || mode > exports.UNZIP) {
throw new TypeError('Bad argument');
}
this.dictionary = null;
this.err = 0;
this.flush = 0;
this.init_done = false;
this.level = 0;
this.memLevel = 0;
this.mode = mode;
this.strategy = 0;
this.windowBits = 0;
this.write_in_progress = false;
this.pending_close = false;
this.gzip_id_bytes_read = 0;
}
Zlib.prototype.close = function () {
if (this.write_in_progress) {
this.pending_close = true;
return;
}
this.pending_close = false;
assert(this.init_done, 'close before init');
assert(this.mode <= exports.UNZIP);
if (this.mode === exports.DEFLATE || this.mode === exports.GZIP || this.mode === exports.DEFLATERAW) {
zlib_deflate.deflateEnd(this.strm);
} else if (this.mode === exports.INFLATE || this.mode === exports.GUNZIP || this.mode === exports.INFLATERAW || this.mode === exports.UNZIP) {
zlib_inflate.inflateEnd(this.strm);
}
this.mode = exports.NONE;
this.dictionary = null;
};
Zlib.prototype.write = function (flush, input, in_off, in_len, out, out_off, out_len) {
return this._write(true, flush, input, in_off, in_len, out, out_off, out_len);
};
Zlib.prototype.writeSync = function (flush, input, in_off, in_len, out, out_off, out_len) {
return this._write(false, flush, input, in_off, in_len, out, out_off, out_len);
};
Zlib.prototype._write = function (async, flush, input, in_off, in_len, out, out_off, out_len) {
assert.equal(arguments.length, 8);
assert(this.init_done, 'write before init');
assert(this.mode !== exports.NONE, 'already finalized');
assert.equal(false, this.write_in_progress, 'write already in progress');
assert.equal(false, this.pending_close, 'close is pending');
this.write_in_progress = true;
assert.equal(false, flush === undefined, 'must provide flush value');
this.write_in_progress = true;
if (flush !== exports.Z_NO_FLUSH && flush !== exports.Z_PARTIAL_FLUSH && flush !== exports.Z_SYNC_FLUSH && flush !== exports.Z_FULL_FLUSH && flush !== exports.Z_FINISH && flush !== exports.Z_BLOCK) {
throw new Error('Invalid flush value');
}
if (input == null) {
input = Buffer.alloc(0);
in_len = 0;
in_off = 0;
}
this.strm.avail_in = in_len;
this.strm.input = input;
this.strm.next_in = in_off;
this.strm.avail_out = out_len;
this.strm.output = out;
this.strm.next_out = out_off;
this.flush = flush;
if (!async) {
// sync version
this._process();
if (this._checkError()) {
return this._afterSync();
}
return;
}
// async version
var self = this;
process.nextTick(function () {
self._process();
self._after();
});
return this;
};
Zlib.prototype._afterSync = function () {
var avail_out = this.strm.avail_out;
var avail_in = this.strm.avail_in;
this.write_in_progress = false;
return [avail_in, avail_out];
};
Zlib.prototype._process = function () {
var next_expected_header_byte = null;
// If the avail_out is left at 0, then it means that it ran out
// of room. If there was avail_out left over, then it means
// that all of the input was consumed.
switch (this.mode) {
case exports.DEFLATE:
case exports.GZIP:
case exports.DEFLATERAW:
this.err = zlib_deflate.deflate(this.strm, this.flush);
break;
case exports.UNZIP:
if (this.strm.avail_in > 0) {
next_expected_header_byte = this.strm.next_in;
}
switch (this.gzip_id_bytes_read) {
case 0:
if (next_expected_header_byte === null) {
break;
}
if (this.strm.input[next_expected_header_byte] === GZIP_HEADER_ID1) {
this.gzip_id_bytes_read = 1;
next_expected_header_byte++;
if (this.strm.avail_in === 1) {
// The only available byte was already read.
break;
}
} else {
this.mode = exports.INFLATE;
break;
}
// fallthrough
case 1:
if (next_expected_header_byte === null) {
break;
}
if (this.strm.input[next_expected_header_byte] === GZIP_HEADER_ID2) {
this.gzip_id_bytes_read = 2;
this.mode = exports.GUNZIP;
} else {
// There is no actual difference between INFLATE and INFLATERAW
// (after initialization).
this.mode = exports.INFLATE;
}
break;
default:
throw new Error('invalid number of gzip magic number bytes read');
}
// fallthrough
case exports.INFLATE:
case exports.GUNZIP:
case exports.INFLATERAW:
this.err = zlib_inflate.inflate(this.strm, this.flush
// If data was encoded with dictionary
);if (this.err === exports.Z_NEED_DICT && this.dictionary) {
// Load it
this.err = zlib_inflate.inflateSetDictionary(this.strm, this.dictionary);
if (this.err === exports.Z_OK) {
// And try to decode again
this.err = zlib_inflate.inflate(this.strm, this.flush);
} else if (this.err === exports.Z_DATA_ERROR) {
// Both inflateSetDictionary() and inflate() return Z_DATA_ERROR.
// Make it possible for After() to tell a bad dictionary from bad
// input.
this.err = exports.Z_NEED_DICT;
}
}
while (this.strm.avail_in > 0 && this.mode === exports.GUNZIP && this.err === exports.Z_STREAM_END && this.strm.next_in[0] !== 0x00) {
// Bytes remain in input buffer. Perhaps this is another compressed
// member in the same archive, or just trailing garbage.
// Trailing zero bytes are okay, though, since they are frequently
// used for padding.
this.reset();
this.err = zlib_inflate.inflate(this.strm, this.flush);
}
break;
default:
throw new Error('Unknown mode ' + this.mode);
}
};
Zlib.prototype._checkError = function () {
// Acceptable error states depend on the type of zlib stream.
switch (this.err) {
case exports.Z_OK:
case exports.Z_BUF_ERROR:
if (this.strm.avail_out !== 0 && this.flush === exports.Z_FINISH) {
this._error('unexpected end of file');
return false;
}
break;
case exports.Z_STREAM_END:
// normal statuses, not fatal
break;
case exports.Z_NEED_DICT:
if (this.dictionary == null) {
this._error('Missing dictionary');
} else {
this._error('Bad dictionary');
}
return false;
default:
// something else.
this._error('Zlib error');
return false;
}
return true;
};
Zlib.prototype._after = function () {
if (!this._checkError()) {
return;
}
var avail_out = this.strm.avail_out;
var avail_in = this.strm.avail_in;
this.write_in_progress = false;
// call the write() cb
this.callback(avail_in, avail_out);
if (this.pending_close) {
this.close();
}
};
Zlib.prototype._error = function (message) {
if (this.strm.msg) {
message = this.strm.msg;
}
this.onerror(message, this.err
// no hope of rescue.
);this.write_in_progress = false;
if (this.pending_close) {
this.close();
}
};
Zlib.prototype.init = function (windowBits, level, memLevel, strategy, dictionary) {
assert(arguments.length === 4 || arguments.length === 5, 'init(windowBits, level, memLevel, strategy, [dictionary])');
assert(windowBits >= 8 && windowBits <= 15, 'invalid windowBits');
assert(level >= -1 && level <= 9, 'invalid compression level');
assert(memLevel >= 1 && memLevel <= 9, 'invalid memlevel');
assert(strategy === exports.Z_FILTERED || strategy === exports.Z_HUFFMAN_ONLY || strategy === exports.Z_RLE || strategy === exports.Z_FIXED || strategy === exports.Z_DEFAULT_STRATEGY, 'invalid strategy');
this._init(level, windowBits, memLevel, strategy, dictionary);
this._setDictionary();
};
Zlib.prototype.params = function () {
throw new Error('deflateParams Not supported');
};
Zlib.prototype.reset = function () {
this._reset();
this._setDictionary();
};
Zlib.prototype._init = function (level, windowBits, memLevel, strategy, dictionary) {
this.level = level;
this.windowBits = windowBits;
this.memLevel = memLevel;
this.strategy = strategy;
this.flush = exports.Z_NO_FLUSH;
this.err = exports.Z_OK;
if (this.mode === exports.GZIP || this.mode === exports.GUNZIP) {
this.windowBits += 16;
}
if (this.mode === exports.UNZIP) {
this.windowBits += 32;
}
if (this.mode === exports.DEFLATERAW || this.mode === exports.INFLATERAW) {
this.windowBits = -1 * this.windowBits;
}
this.strm = new Zstream();
switch (this.mode) {
case exports.DEFLATE:
case exports.GZIP:
case exports.DEFLATERAW:
this.err = zlib_deflate.deflateInit2(this.strm, this.level, exports.Z_DEFLATED, this.windowBits, this.memLevel, this.strategy);
break;
case exports.INFLATE:
case exports.GUNZIP:
case exports.INFLATERAW:
case exports.UNZIP:
this.err = zlib_inflate.inflateInit2(this.strm, this.windowBits);
break;
default:
throw new Error('Unknown mode ' + this.mode);
}
if (this.err !== exports.Z_OK) {
this._error('Init error');
}
this.dictionary = dictionary;
this.write_in_progress = false;
this.init_done = true;
};
Zlib.prototype._setDictionary = function () {
if (this.dictionary == null) {
return;
}
this.err = exports.Z_OK;
switch (this.mode) {
case exports.DEFLATE:
case exports.DEFLATERAW:
this.err = zlib_deflate.deflateSetDictionary(this.strm, this.dictionary);
break;
default:
break;
}
if (this.err !== exports.Z_OK) {
this._error('Failed to set dictionary');
}
};
Zlib.prototype._reset = function () {
this.err = exports.Z_OK;
switch (this.mode) {
case exports.DEFLATE:
case exports.DEFLATERAW:
case exports.GZIP:
this.err = zlib_deflate.deflateReset(this.strm);
break;
case exports.INFLATE:
case exports.INFLATERAW:
case exports.GUNZIP:
this.err = zlib_inflate.inflateReset(this.strm);
break;
default:
break;
}
if (this.err !== exports.Z_OK) {
this._error('Failed to reset stream');
}
};
exports.Zlib = Zlib;