Streaming compression instance commands are produced by the zlib stream command. The man page does not indicate the polynomial that it uses to calculate the CRC-32. It also seem possible that future versions of zlib may fix this bug and start accepting 8 and -8 as is. ZLIB current version is 1. h and see if zlib's handling of errno is satisfactory. 2 is to compile with the 'verbose' macro defined to be -1. It can be found in the FastCRC. Requires a signed-in GitHub account. If given, initValue is used to initialize the checksum engine. Four bytes at a time algorithms exist in C code under CDDL and zlib, but differ a lot from this one. 8 might allow context-dependent attackers to have unspecified impact via vectors involving big-endian CRC calculation. The zlib compressed data format is described in RFC 1950, which is a wrapper around a deflate stream which is described in RFC 1951. As it says in the title when trying. 比如 import zlib text = 'abcd' zlib. 3 This patch does not contain our local changes for Windows CE. Despite its name, the DEFLATE encoding of a resource is specified to be the ZLIB data format. 04 for this tutorial). If the SPL extension is available, a Phar object can be used as an array to iterate over a phar's contents or to read files directly from the phar. This has the effect of shortening the hash chain and increasing the quality of each match, at the opportunity cost of matches of length three. Moved all basic imported functions in a standalone unit, zlibpas. Daher möchte ich gerne den crc32 Befehl aus dem zlib Paket benutzen. The zlib data format is itself portable across platforms. 9 values 8 and -8 are automatically changed to 9 and -9. of course, always ignore the first test, which load the file in system cache. 5 of the zlib library. (A "C" command-line program is also available. Introduction; About DotNetZip; Getting Started. Go to the documentation of this file. 2014-12-29 如何在ubuntu中安装zlib和zlib-devel 23 2016-12-11 如何在linux平台上编译安装zlib软件 2015-01-27 如何在linux平台上编译安装zlib软件. dsp --- httpd-2. The functions in this module allow compression and decompression using the zlib library, which is based on GNU zip. Further resources on Zlib-Libpng License (Zlib). 이 값들은 zlib이 데이터를 처리할 때마다 갱신되며 avail_in이 0이 되면 zlib을 이용하는 외부 프로그램이 zlib에게 다음 (입력) 데이터 스트림을 제공해주어야하며, avail_out이 0이 되면 외부 프로그램이 압축된 데이터를 별도의 공간으로 옮기거나 적절한 처리를 하여. Neither checksum is billed as cryptographically secure, and they are only intended for use for data integrity verification. It's not easily lifted out because it's implemented as a kind of memcpy-with-checksum. The crc32_big function in crc32. I noticed my https would not load when I updated zlib because it wants zlib-1. Files on a file system compressed with gzip format. In addition to compression and decompression functions, zlib includes two functions for computing checksums of data, adler32() and crc32(). The zlib module provides a lower-level interface to many of the functions in the zlib compression library from the GNU project. Linux for SPARC Package Information License information for packages included with Linux for SPARC. crc32 (as implemented by the zlib developers). If a custom format is developed using the raw deflate format for compressed data, it is recommended that a check value such as an adler32 or a crc32 be applied to the uncompressed data as is done in the zlib, gzip, and zip formats. crc32 matches, e. Carry-less Multiplication (CLMUL) is an extension to the x86 instruction set used by microprocessors from Intel and AMD which was proposed by Intel in March 2008 and made available in the Intel Westmere processors announced in early 2010. When I then try to build both the static and the shared library, the build process of libpng itself fails with similar "undefined reference to `_imp__crc32'" errors, when it tries to link libpng15. 626: 627 =item B<-MemLevel> 628: 629: For a definition of the meaning and valid values for C 630: refer to the I documentation for I. local const unsigned long FAR crc_table[TBLS][256] Definition: crc32. ZLIB_LIBRARIES - List of libraries when using zlib. c of the component CRC Calculation. crc32(s, [size][, crc]) -> n Start or update a running CRC-32B of a string or cdata buffer and return the updated CRC-32. Old code base released in 1995. Using zlib dll how can i compress and decompress data in C#. adler32) and CRC32 (zlib. Provides classes for reading and writing the standard ZIP and GZIP file formats. Information on source package zlib. Pythonモジュールと zlib ライブラリの1. How To Install OpenCV In Ubuntu Linux. import zlib import sys import urllib2 def __zlib_csum(url, func): if isinstance(url, basestring if sys. 0 was released on March 1, 2012. 3 * For conditions of distribution and use, see copyright notice in zlib. sysroot zlib plugin issue. 0 For projects that support PackageReference , copy this XML node into the project file to reference the package. CVE-2016-9841: inffast. Upgrade Blockers. #define GF2_DIM 32 /* dimension of GF(2) vectors (length of CRC) */ Definition at line 342 of file crc32. crc32(s, [size][, crc]) -> n Start or update a running CRC-32B of a string or cdata buffer and return the updated CRC-32. Unwrapping the zlib-format with utl_compress takes just a little more effort. 巡回冗長検査(じゅんかいじょうちょうけんさ、英: Cyclic Redundancy Check, CRC )は、誤り検出符号の一種で、主にデータ転送などに伴う偶発的な誤りの検出によく使われている。. Streaming compression instance commands are produced by the zlib stream command. com/public/1zuke5y/q3m. It includes in-memory compression / decompression, creating. crc32 and Adler-32) and leveraging SIMD optimizations. It's not easily lifted out because it's implemented as a kind of memcpy-with-checksum. #define inflateInit ( strm ) inflateInit_((strm), ZLIB_VERSION, sizeof())Definition at line 1181 of file zlib. To build zlib you can use win32/makefile. Which type of checksum is computed (Adler-32 or CRC-32) depends on the compression format of the stream. 8 might allow context-dependent attackers to have unspecified impact by leveraging improper pointer arithmetic. This guide describes the native hadoop library and includes a small discussion about native shared libraries. 8 The main problem with upgrading is actually importing the sources properly into svn. 0 was released on March 1, 2012. Python: generates crc32 and adler32 checksum for big files import zlib import sys import urllib2 def __zlib_csum(url, func): if isinstance(url, basestring if sys. adler32(s [,crc]) 返回字符串的Adler32校验码。参数''crc''用于增量校验。Adler32校验比普通CRC32校验快。Adler32校验只能用于检测数据是否损坏,而不用于加密。. Parameters. 11 Reapply and regenerate all local patches to upstream zlib 1. c in zlib 1. This means that half the possible answers are numerically different on these two kinds of platforms. [2019-08-23T23:03:17] The server time is now Friday, August 23rd, 2019 11:03:17pm /bin/sh -c if [ ! -d "/Users/racket/build/plt//build/cs" ] ; then git clone "/Users. Generally, looking like the problem is solved now, but i'll appreciate if you would add more comments. Import CVE fixes that impact zlib version 1. Eventually, after asking on Mastodon, Kepstin figured out what variant of CRC32 is being used in the original code. The crc32_big function in crc32. 在实际应用中经常会遇到要压缩数据的问题,常见的压缩格式有zip和rar,而Linux下那就更多了,bz2,gz,xz什么的都有,单单Linux下的解压和压缩命令就有好多呢?. Update Zlib to version 1. the problem is that it won't match a CRC32 generated previously from Python's zlib module: crc32 = zlib. Package ‘digest’ For crc32, code from the zlib library by Jean-loup Gailly and Mark Adler is used. 11 Explicitly specify 9 as the minimum windowBits value (representing a 512-byte window) during compression in net/websockets even when 8 (representing 256) is received. crc32(s) The code above generates the following result. crc32 (data [, value]) ¶ Computes a CRC (Cyclic Redundancy Check) checksum of data. 11 Reapply and regenerate all local patches to upstream zlib 1. Table of contents. 1 Generator usage only permitted with license. This can be. On Windows, the zlib and bzip2 filters are disabled by default; to enable support for these filters, you will need to set variables indicating the location of the source files, if building from the source, or the location of the headers and binaries, if using pre-built binaries. A good perf boost was achieved on Chromium's zlib by optimizing the checksums (i. The implementation provides filters that uncompress during reading and compress during writing. zlib的一些函数: zlib. They are extracted from open source Python projects. crc32 (crc, buffer) Compute a crc32 checksum Without any parameters, returns the initial crc32 value. Configuration. These releases provide fixes for quite a few bugs, some of which are security related. A lot of other popular projects use zlib (pngimage, graphicEx) and they include their own version of the library. This was previously silently done during compression. [] Apparently this is caused by the definition -DZLIB_DLL, commenting it out in CMakeLists. stream close. 5, which dates back to January 2012. c in zlib 1. Calculating the crc32 of a file in Python is very simple but I often forgot how to do. The most widespread implementation of CRC32 is based on a look-up table with 256 entries of 32-bit values (total: e. So, my question is, what is going wrong?. When I then try to build both the static and the shared library, the build process of libpng itself fails with similar "undefined reference to `_imp__crc32'" errors, when it tries to link libpng15. New creates a new hash. The following are code examples for showing how to use zlib. [] Apparently this is caused by the definition -DZLIB_DLL, commenting it out in CMakeLists. x, gzopen used the zlib library to open the underlying file. Intel's zlib with SSE4. 2 and later versions allows remote attackers to cause a denial of service (crash) via a crafted compressed stream with an incomplete code description of a length greater than 1, which leads to a buffer overflow, as demonstrated using a crafted PNG file. crc32 and binascii. "The crc32_big function in crc32. c in zlib 1. 04 for this tutorial). Generated on 2017-Dec-13 from project zlib revision 255606 Powered by Code Browser 2. Difference between 1. This was previously silently done during compression. llvm::zlib Namespace Reference. This issue affects the function crc32_big in the library zlib of the file crc32. 4 21 DYNAMIC_CRC_TABLE and MAKECRCH can be #defined to write out crc32. Requires a signed-in GitHub account. To fill this lack another developer created a small wrapper over zlib allowing to bypass this problem. Was built to learn pip packaging, and implement compression before encryption. It also seem possible that future versions of zlib may fix this bug and start accepting 8 and -8 as is. refer to the I documentation for I. Furthermore, there is no java code like it that I can find anywhere. pdf), Text File (. A negative WindowBits value makes zlib ignore the zlib header (and checksum) from the stream. inflate() will then process raw deflate data, not looking for a. It also does not indicate the Endean-ness of the bytes as they are read from a file. I suspect you have replaced /usr/bin/libtool with a copy of GNU libtool. The zlib compressed data format is described in RFC 1950, which is a wrapper around a deflate stream which is described in RFC 1951. In my hands it's looking pretty good, although I haven't tested it on AMD systems or on 32-bit platforms yet to see how portable it is. On 22 August 2018 at 23:09, Ashok Arora wrote: > Test this in the interpreter:-> > import zlib > zlib. #ifdef _WIN32 #define ZLIB_WINAPI #endif #include "zlib. About SwiftAPI. h" So, looking like ZLIB_WINAPI is used only with win32. Parameters. Take care when comparing ruby results with php results. Much of this success is probably due its open source status and wide portability—from Palm Pilots to IBM mainframes, you'll find zlib version for every platform. zlib, bz2 and crc32 is achieved without any dependency other than the external zlib or bz2 extension. return ~crc32 & 0xffffffff Compression is performed using zlib (with the library containing the string “Fast decoding Code from Chris Anderson”), and can be inflated using the following code:. of course, always ignore the first test, which load the file in system cache. read(BUFFER_SIZE) if not data: break crc = crc32(data, crc. If we use the crc32, what is the maximum number of urls can be used so that we can avoid duplicates? What could be the approximative string length to keep the checksum to be 2^32?. That means 2 or 3 instances of the C library included in an application! I hope one day this will be ended. Moreover, i found that usually #define ZLIB_WINAPI is used kinda. c in zlib 1. Generated on 2017-Dec-13 from project zlib revision 255606 Powered by Code Browser 2. encoding-index-simpchinese. This issue affects the function crc32_big in the library zlib of the file crc32. c -- compute the CRC-32 of a data stream: 2: n/a /* CRC-32 polynomial */ 388: n/a. Go to the documentation of this file. Introduction; About DotNetZip; Getting Started. (See the README file for details of how to override this behaviour) If you decide to use a different version of the zlib library, you need to be aware of the following issues. Package ‘digest’ For crc32, code from the zlib library by Jean-loup Gailly and Mark Adler is used. The crc32() function shall compute a running Cyclic Redundancy Check checksum, as defined in ITU-T V. The summary is that CloudFlare's fork is much faster with decompression and a little faster with high compression levels, while Intel's is faster with low and medium compression levels. h header but there is no library created for user land usage and also some architectures have assembly code as well. */ u_int32_t crc_tab[256]; /* chksum_crc() -- to a given block, this one calculates the * crc32-checksum until the length is * reached. crc32 :: Signal (Unsigned 8) -> Signal (Unsigned 32) crc32 = mealy crc32T 0 topEntity :: Signal (Unsigned 8) -> Signal (Unsigned 32) topEntity = crc32 The topEntity is like a main function. Its compression algorithm is deflate. Zlib supports reading and writing of Zlib compressed data format (RFC1950), DEFLATE compressed data format (RFC1951), and GZIP file format (RFC1052). txt) or read online for free. Difference between 1. NET is a 100% managed version of ZLIB compression library which implements deflate and inflate compression algorithms. -----At first I thought that zlib wasn't installed, so I downloaded it from www. (I couldn’t remember the last time I was actually logged on. 8 might allow context-dependent attackers to have unspecified impact by leveraging improper pointer arithmetic. I verified (with the zlib authors) that the best way to do this in zlib 1. Generated: 2015-04-30 16:17:40 UTC. 6 を導入したときのメモ. For now, CRC32 and Adler32 are supported; they are implemented as FFI bindings to efficient code from zlib. Overall *really* solid work and thanks for sharing the code and the results with the community. Go to the SVN repository for this file. prompt$ cobc -xj crc32-zlib. decompress(t) print zlib. The most widespread implementation of CRC32 is based on a look-up table with 256 entries of 32-bit values (total: e. NY-YIP members and insurance professiona. io/, and the place to go for questions about the library is the png-mng-implement mailing list. 13 zlib-- Compression compatible with gzip. Check out the release announcement here if you haven’t already, to learn about major changes and new features. For applications that require data compression, the functions in this module allow compression and decompression, using the zlib library. Discards any remaining input and output. blob: 789ad62ea20bc291513c34905f4d8e055ee80634 [] [] []. Definition at line 219 of file crc32. I learned that zlib1. zlib is designed to be a free, general-purpose, legally unencumbered -- that is, not covered by any patents -- lossless data-compression library for use on virtually any computer hardware and operating system. llvm::zlib Namespace Reference. (A "C" command-line program is also available. This was previously silently done during compression. Download zlib1. In Compress::Zlib version 1. Visual C++ allows you to produce managed and unmanaged code into the same assembly. This package provides efficient cryptographic hash implementations for strict and lazy bytestrings. It allow to easily manage a zip file but, currently, doesn't have the feature for create zip file password protected. Furthermore, unlike the patented LZW. A free general-purpose compression library. static VALUE rb_zlib_crc32_combine(VALUE klass, VALUE crc1, VALUE crc2, VALUE len2) { return ULONG2NUM( crc32_combine(NUM2ULONG(crc1), NUM2ULONG(crc2), NUM2LONG(len2))); }. Comparison of Intel and CloudFlare zlib patches Posted on 2014-08-04 in General Edit: 2015-06-05 There's a post with updated results , using a newer version of the Cloudflare patches as well as adding zlib-ng to the mix. The returned Hash32 also implements encoding. Active gives the filename + CRC32 and no warning for a directory. Difference between 1. Zlib has been the gold standard for lossless compression almost since its introduction in 1995. len2 is the length of the string used to generate crc2. Context Lacks any optimizations for ARM CPUs. Daher möchte ich gerne den crc32 Befehl aus dem zlib Paket benutzen. Maybe it'd be better to just require zlib unconditionally (or mark building it really unsupported) rather than bundling extra algorithms that will be used only conditionally (until someone mistakenly uses it unconditionally, and LLVM would start using different CRC32 impls in different places) like this. 8 might allow context-dependent attackers to have unspecified impact via vectors involving big-endian CRC calculation. By default, zLib uses C calling conventions (CDECL). We use cookies for various purposes including analytics. This format consists of two header bytes; the first contains the compression method and window-size information (the low bits of the byte are 0x08. Add 32 to windowBits to enable zlib and gzip decoding with automatic header detection, or add 16 to decode only the gzip format (the zlib format will return a Z_DATA_ERROR). html # This program is in the public domain. Generated on 2017-Dec-13 from project zlib revision 255606 Powered by Code Browser 2. 9 values 8 and -8 are automatically changed to 9 and -9. Deflate compression is an LZ77 derivative used in zip, gzip, pkzip, and related programs. The simplest way to work with zlib requires holding all of the data to be compressed or decompressed in memory. It's not easily lifted out because it's implemented as a kind of memcpy-with-checksum. dsp --- httpd-2. The return value is the zlib function returns 00830 the required initial value for the checksum. zlib - A Massively Spiffy Yet Delicately Unobtrusive Compression Library (Also Free, Not to Mention Unencumbered by Patents). The crc32() function shall return the new checksum. This page was automatically generated by the LXR engine. Calculating CRC32 checksum with Python; Browse pages. This made things especially tricky when a Perl filehandle was passed to gzopen. In Django Design Patterns, the author recommends using zlib. dll is the new version of zlib. crc32() which can return a negative 32-bit int value, so for example print '%x' % zlib. 1 /* crc32. dsp httpd-2. ハッシュ値をチェックできるフリーソフト、HashMyFilesの紹介。ドラッグ&ドロップするだけでMD5、SHA1、CRC32などのハッシュ値を計算する事ができます。. Created Aug 8, 2011, Vasil Dimov, based on mysys/my_crc32. c in zlib 1. STREAMING INSTANCE COMMAND Streaming compression instance commands are produced by the zlib stream command. Generally, looking like the problem is solved now, but i'll appreciate if you would add more comments. Parameters. After the end of the loop, exclusive-OR the calculated CRC value with 0xffffffff (this is identical to doing a binary NOT on the CRC value). To build zlib you can use win32/makefile. crc32 and binascii. The crc32() function shall compute a running Cyclic Redundancy Check checksum, as defined in ITU-T V. 2/PLCMUL CRC32: Unfortunately they hooked their new CRC32 code into the compression code, rather than doing what CloudFlare did and changing the stock CRC32 implementation. On 22 August 2018 at 23:09, Ashok Arora wrote: > Test this in the interpreter:-> > import zlib > zlib. __file__ > > It will return the location of zlib module. c in zlib 1. Gzip and PNG formats are designed to use Zlib and choose to have an optional CRC32 checksum of the compressed zlib data instead of the original data. Hopefully it helps you!. gcc mingw32-make install prefix=c:\mingw -fmakefile. STREAMING INSTANCE COMMAND Streaming compression instance commands are produced by the zlib stream command. 11; CF-ZLIB is based on 1. Computes the CRC32 checksum for the source data buffer. What does "/usr/bin/libtool --version" say?If it says it's GNU libtool, then I'm right and you should restore /usr/bin/libtool to the version that Apple provides, then clean zlib and try again. i have used zlib to calculate crc32. If value is present, it is used as the starting value of the checksum; otherwise, a default value of 0 is used. In addition to those below, you can also define LODEPNG_NO_COMPILE_CRC to allow implementing a custom lodepng_crc32. level is an integer from 1 to 9 controlling the level of compression; 1 is fastest and produces the least compression, 9 is slowest and produces the most. By default Compress::Raw::Zlib will build with a private copy of version 1. This impacts the speed of the hashing operating itself, but also improves the string-matching time, due to the good quality of the hash. The New York Young Insurance Professionals hosted its 27 th Annual Golf Outing at The Seawane Country Club in Hewlett Harbor on August 12. This format consists of two header bytes; the first contains the compression method and window-size information (the low bits of the byte are 0x08. 0 Data Remainder Remainder Divisor CRC Data Zero, accept Non-zero, reject CRC n bits n+1 bits Multi-Buffer: CRYPTOGRAPHIC HASHING Dog 06d80e7 b0C50bs 49a509t b49f249 24e8c8o 05x84q4 SHA-1, SHA-256, SHA-512, MD5. - Find zlib Find the native ZLIB includes and library ZLIB_INCLUDE_DIR - where to find zlib. Unfortunately, Intel's code is full of strange looking constants that have been generated from CRC-32-IEEE polynomial. Using zlib dll how can i compress and decompress data in C#. compressobj([level])¶ Returns a compression object, to be used for compressing data streams that won't fit into memory at once. After this command, the stream command cannot be used anymore. version_info[0] < 3 else str Python: string equals ignore case. After the compressed data, a 32bit CRC-32 and 32bit original datasize field complete the format. The zlib compressed data format is described in RFC 1950, which is a wrapper around a deflate stream which is described in RFC 1951. c in zlib 1. the problem is that it won't match a CRC32 generated previously from Python's zlib module: crc32 = zlib. This is all 00039 the information needed to generate CRC's on data a byte at a time for all 00040 combinations of CRC register values and incoming bytes. com/public/1zuke5y/q3m. Compressdev level 0 enables “No Compression”, which passes the uncompressed data to the output buffer, plus deflate headers. Eventually, after asking on Mastodon, Kepstin figured out what variant of CRC32 is being used in the original code. Cyclic redundancy check, CRC) — алгоритм нахождения контрольной суммы, предназначенный для проверки целостности данных. The implementation provides filters that uncompress during reading and compress during writing. Don't confuse with ordinary CRC-32. ) Additional files, CRC16Dem and CRC32Dem, show how to create a command-line program to calculate CRC values. Copy SSH clone URL [email protected] zlib is also a crucial component of many software platforms including Linux, macOS, and iOS. I'm not sure what is going on here This is an OpenVZ 6 CT that has been running flawlessly for years, however, two days ago MySQL started to crash/restart at random intervals. Maybe its worth adding perl-Archive-Zip to current for its crc32 binary? I have not found another good way of generating crc32 sums on linux and they are very useful for comparison with documentation from some online communities that still (Only) use crc32 sums Its also a build dependency for libreoffice. On Windows, the zlib and bzip2 filters are disabled by default; to enable support for these filters, you will need to set variables indicating the location of the source files, if building from the source, or the location of the headers and binaries, if using pre-built binaries. NY-YIP members and insurance professiona. #define GF2_DIM 32 /* dimension of GF(2) vectors (length of CRC) */ Definition at line 342 of file crc32. crc32 and Adler-32) and leveraging SIMD optimizations. The zlib compression library provides in-memory compression and decompression functions, including integrity checks of the uncompressed data. crc32) are available in Python, though not via hashlib since they were never meant to be secure. crc32 (as implemented by the zlib developers). Created Aug 8, 2011, Vasil Dimov, based on mysys/my_crc32. Attachments (0) ETH Zurich import zlib import sys file_name = sys. 8 [2] that is currently used by rsync. Allow the zlib. Linux for SPARC Package Information License information for packages included with Linux for SPARC. 8 might allow context-dependent attackers to have unspecified impact via vectors involving big-endian CRC calculation. x instructions. This allows computing a running checksum over the concatenation of several inputs. 1 Generator usage only permitted with license. In Compress::Zlib version 1. It turns out that this is directly doable in Rust with the git version of the crc crate. 04 for this tutorial). Moreover, i found that usually #define ZLIB_WINAPI is used kinda. stream close. llvm::zlib Namespace Reference. Hopefully it helps you!. Eventually, after asking on Mastodon, Kepstin figured out what variant of CRC32 is being used in the original code. More recently we have investigated the speed of the CRC32 calculations in great detail and found that indeed these software implementations are pretty slow and can't even keep up with the fast file systems we are using. Module zlib. ZLIB Progress We have been trying to land the Cloudflare ZLIB ("CF-ZLIB") patches into ROOT. h for Z_FINISH when the entire input. Now try configuring / installing ImageMagick again. The Adler32 and CRC32 checksums were calculated using the zlib data compression library [18], Fletcher32 was implemented using the recommendations in [19] and for MD5 we used the OpenSSL library. set checksum [zlib adler32 data ?startvalue?] # adler32 calculates a quick "Adler-32" checksum set checksum [zlib crc32 data ?startvalue?] # crc32 calculates the standard "CRC-32" checksum set cdata [zlib compress data ?level?] # zlib-compress data with optional compression level set ddata [zlib deflate data ?level?] # headerless compression. crc32(buffer ) generates the FutureWarning. import zlib import sys import urllib2 def __zlib_csum(url, func): if isinstance(url, basestring if sys. How to check crc of a file? Ask Question Asked 6 years, 2 months ago. Using CWE to declare. zlib - A Massively Spiffy Yet Delicately Unobtrusive Compression Library (Also Free, Not to Mention Unencumbered by Patents). dsp 2004-11. The reason is that the zlib. Quickly fork, edit online, and submit a pull request for this page. Several companies have made zlib significantly faster by using modern CPU instructions (on the x86-64 arch) – typically, the CRC32 instructions, carryless multiplication (PCLMULQDQ), maybe some window rolling and SSE 4. One of the news: zlib is needed. txt unless that's a recent addition. Package zlib implements reading and writing of zlib format compressed data, as specified in RFC 1950. Intel's zlib with SSE4. For now, CRC32 and Adler32 are supported; they are implemented as FFI bindings to efficient code from zlib.