Info-ZIP is a set of

open-source software Open-source software (OSS) is computer software that is released under a license in which the copyright holder grants users the rights to use, study, change, and distribute the software and its source code to anyone and for any purpose. Op ...

to handle ZIP archives. It has been in circulation since 1989. It consists of 4 separately-installable packages: the Zip and UnZip command-line utilities; and WiZ and MacZip, which are

graphical user interface The GUI ( "UI" by itself is still usually pronounced . or ), graphical user interface, is a form of user interface that allows users to interact with electronic devices through graphical icons and audio indicator such as primary notation, inste ...

s for archiving programs in

Microsoft Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...

and

classic Mac OS Mac OS (originally System Software; retronym: Classic Mac OS) is the series of operating systems developed for the Macintosh family of personal computers by Apple Computer from 1984 to 2001, starting with System 1 and ending with Mac OS 9. The ...

, respectively. Info-ZIP's Zip and UnZip have been ported to dozens of

computing platform A computing platform or digital platform is an environment in which a piece of software is executed. It may be the hardware or the operating system (OS), even a web browser and associated application programming interfaces, or other underlying s ...

s. The UnZip web page describes UnZip as "The Third Most Portable Program in the World", surpassed by Hello World,

C-Kermit Kermit is a computer file transfer/management protocol and a set of communications software tools primarily used in the early years of personal computing in the 1980s. It provides a consistent approach to file transfer, terminal emulation, scrip ...

, and possibly the

Linux kernel The Linux kernel is a free and open-source, monolithic, modular, multitasking, Unix-like operating system kernel. It was originally authored in 1991 by Linus Torvalds for his i386-based PC, and it was soon adopted as the kernel for the GNU ope ...

. The "zip" and "unzip" programs included with most Linux and Unix distributions are Info-ZIP's Zip and UnZip. In addition to the Info-ZIP releases themselves, parts of Info-ZIP, including

zlib zlib ( or "zeta-lib", ) is a software library used for data compression. zlib was written by Jean-loup Gailly and Mark Adler and is an abstraction of the DEFLATE compression algorithm used in their gzip file compression program. zlib is also a ...

, have been used in numerous other

file archiver A file archiver is a computer program that combines a number of files together into one archive file, or a series of archive files, for easier transportation or storage. File archivers may employ lossless data compression in their archive formats ...

s and other programs. Many Info-ZIP programmers have also been involved in other projects closely related to the DEFLATE compression algorithm, such as the PNG image format and the

software library.

Features

The UnZip package also includes three additional utilities: * fUnZip extracts a file in a ZIP or gzip file directly to output from archives or other

piped A pipe is a tubular section or hollow cylinder, usually but not necessarily of circular cross-section, used mainly to convey substances which can flow — liquids and gases (fluids), slurries, powders and masses of small solids. It ...

input. * UnZipSFX is software to make a ZIP file into an executable self-extracting archive. * ZipInfo outputs, in a variety of formats, information about ZIP files and their contents. The Zip package includes three additional utilities: * ZipCloak adds or removes password encryption from file in a ZIP archive. * ZipNote allows the modification of comment fields in ZIP archives. * ZipSplit splits a ZIP archive into sections for separate disks or downloads.

History

UnZip

UnZip 1.0 (March 1989) was released by Samuel M. Smith. It was written in

Pascal Pascal, Pascal's or PASCAL may refer to: People and fictional characters * Pascal (given name), including a list of people with the name * Pascal (surname), including a list of people and fictional characters with the name ** Blaise Pascal, Fren ...

and C. Pascal was abandoned soon after. UnZip 2.0 (September 1989) was released by Samuel M. Smith. It included support for the "unimploding" (method 6) introduced by

PKZIP PKZIP is a file archiving computer program, notable for introducing the popular ZIP file format. PKZIP was first introduced for MS-DOS on the IBM-PC compatible platform in 1989. Since then versions have been released for a number of other ...

1.01. George Sipe created Unix version. UnZip 2.0a (December 1989) was released by Carl Mascott and John Cowan. In Spring 1990, Info-ZIP was formed as a

mailing list A mailing list is a collection of names and addresses used by an individual or an organization to send material to multiple recipients. The term is often extended to include the people subscribed to such a list, so the group of subscribers is re ...

SIMTEL20 Simtel (sometimes called Simtelnet, originally SIMTEL20) was an important long-running archive of freeware and shareware for various operating systems. The Simtel archive had significant ties to the history of several operating systems: it was in ...

, and released UnZip 3.0 (May 1990) became the first public release by Info-ZIP group. UnZip 4.0 (December 1990) adds support of "central directory" within .ZIP archive. UnZip 5.0 (August 1992) introduces support of DEFLATE (method 8) compression method, used in

1.93a. Method 8 has become the de facto base standard for ZIP archives. In 1994 and 1995 Info-ZIP turned a corner, and effectively became the ''de facto'' ZIP program on non-

MS-DOS MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few ope ...

systems. A huge number of ports were released that year, including numerous

minicomputer A minicomputer, or colloquially mini, is a class of smaller general purpose computers that developed in the mid-1960s and sold at a much lower price than mainframe and mid-size computers from IBM and its direct competitors. In a 1970 survey, ...

s, mainframes and practically every

microcomputer A microcomputer is a small, relatively inexpensive computer having a central processing unit (CPU) made out of a microprocessor. The computer also includes memory and input/output (I/O) circuitry together mounted on a printed circuit board (PC ...

ever developed. UnZip 5.41 (April 2000) was relicensed under Info-ZIP License. UnZip 5.50 (February 2002) adds support of Deflate64 (method 9) decompression. UnZip 6.0 adds support of "Zip64" .ZIP archive and bzip2 (method 12) decompression. Support for bzip2-style compression was also in Zip from 3.0f beta.

Zip

Zip 1.9 (August 1992) introduces support of DEFLATE (method 8) compression method. Method 8 has become the de facto base standard for ZIP archives. Zip 2.0 (September 1993) has many portability improvements. Zip 2.1 (May 1996) added new "UNIX" time info to preserve file times across timezones and OSes. Zip 2.3 (December 1999) was the first Info-ZIP archiver tool under the new BSD-like Info-ZIP License. Zip 3.0 (2008-07-07) supports "Zip64" .ZIP archive, more than 65536 files per archive, multi-part archive, bzip2 compression, Unicode (UTF-8) filename and (partial) comment, Unix 32-bit UIDs/GIDs

WiZ

WiZ 4.0 (November 1997) was released by Info-ZIP. WiZ 5.01 (April 2000) was relicensed under Info-ZIP License.

MacZip

MacZip 1.05 (July 2000) was released under Info-ZIP License. MacZip 1.06 was released in February 2001. It was written by Dirk Hasse.

Forks and patches

As a slowly-updated open software package, many patches have been written by various Linux distributions to improve info-zip tools. In addition, from 2015 to 2019, 14 unzip vulnerabilities have been published on the CVE list without version or website updates from info-zip. (Three CVEs from 2014 in oCERT-2014-011 are left out of most statistics; info-zip did provide patches on their now-defunct forum.)

Mark Adler Mark Adler (born 1959) is an American software engineer. He is best known for his work in the field of data compression as the author of the Adler-32 checksum function, and a co-author together with Jean-loup Gailly of the zlib compression librar ...

has a set of patches for unzip 6.0 that detects zip bombs of the overlapping type. This issue has a CVE ID of CVE-2019-13232. The Debian project provides various patches to correct typographical errors and security issues, including the 17 unzip CVEs. It also hardens against format string injection and other obvious security issues. To deal with pre-UTF-8 Zip files created on other

code pages In computing, a code page is a character encoding and as such it is a specific association of a set of printable characters and control characters with unique numbers. Typically each number represents the binary value in a single byte. (In some co ...

, Giovanni Scafora created a patch that hooks unzip up with

iconv In Unix and Unix-like operating systems, iconv (an abbreviation of internationalization conversion) is a command-line program and a standardized application programming interface (API) used to convert between different character encodings. "It c ...

for encoding conversion. A version of the patch combined with CVE mitigations are provided as a User Package in Arch Linux. The Gentoo project improves upon the hard-coded locales with an external library. The Fedora project (an upstream of

Red Hat Enterprise Linux Red Hat Enterprise Linux (RHEL) is a commercial open-source Linux distribution developed by Red Hat for the commercial market. Red Hat Enterprise Linux is released in server versions for x86-64, Power ISA, ARM64, and IBM Z and a desktop version ...

) applies Adler's patch, most of the Debian patches (or similar), as well as extra security patches like a stack non-execution patch to their unzip. The zip patches are similar to Debian patches.

Official betas

Some official improvements to zip and unzip are stuck in beta-stage as zip 3.1c and unzip 6.10b from 2015. Among other things, both added support for PPMd8 and LZMA compressions in files, support for AES encryption, and included iconv-based Unicode improvements (based on unzip-iconv). A newer release candidate, Zip 3.1d, appeared on the official FTP site in 2015, but the SourceForge page was not updated. Partially due to the added compressors, the zipped file size increased from 1.4 MB (3.1c) to 2.9 MB (3.1d). The antinode.info FTP site seems to be hosting an even more cutting-edge source of info-zip utilities. Individual revisions are organized into folders containing files differing from the previous revision, and zip archives for sources are occasionally released. , the site provides Unzip 6.10c (rev. 25, 21 Dec 2018) and an unarchived development version of Zip 3.1e from August 2019. The owner of the site, Steven Schweda, maintains these versions. Schweda is a member of the original info-zip team.

Replacements

FreeBSD FreeBSD is a free and open-source Unix-like operating system descended from the Berkeley Software Distribution (BSD), which was based on Research Unix. The first version of FreeBSD was released in 1993. In 2005, FreeBSD was the most popular ...

has opted to replace info-zip utilities. It produces a command-line compatible version of based on

libarchive In computing, tar is a computer software utility for collecting many files into one archive file, often referred to as a tarball, for distribution or backup purposes. The name is derived from "tape archive", as it was originally developed to ...

, which also supports zipx and AES.

References

External links

*
Official (legacy) FTP siteSourceforge Patch submissions
{{FLOSS 1989 software Cross-platform free software File archivers Free data compression software Unix archivers and compression-related utilities Software using the BSD license