WinRAR
WinRAR is a trialware file archiver utility for Windows, developed by Eugene Roshal of win.rar GmbH. It can create and view archives in RAR or ZIP file formats, and unpack numerous archive file formats. To enable the user to test the integrity of archives, WinRAR embeds CRC32 or BLAKE2 checksums for each file in each archive. WinRAR supports creating encrypted, multi-part and self-extracting archives.
WinRAR is a Windows-only program. An Android application called "RAR for Android" is also available. Related programs include the command-line utilities "RAR" and "UNRAR" and versions for macOS, Linux, FreeBSD, Windows CE, and MS-DOS.
Evolution
WinRAR and the RAR file format have evolved over time. Support for the archive format RAR5, using the same RAR file extension as earlier versions, was added in version 5.0; files in the older RAR file format have since been referred to as RAR4. WinRAR versions before 5.0 do not support RAR5 archives; only older versions of WinRAR run on Windows versions prior to XP, and cannot open RAR5 archives.The RAR5 file format increased the maximum dictionary size to 1 GiB; 11 different compression directory sizes from 1 MiB to 1 GiB are available, with the default in version 5 increased from 4 MiB to 32 MiB, typically improving compression ratio. AES encryption, when used, is in CBC mode and was increased in strength from 128- to 256-bit. Maximum path length for files in RAR and ZIP archives is increased to 2048 characters.
Options added in v5.0 include 256-bit BLAKE2 file-hashing algorithm instead of default 32-bit CRC32, duplicate file detection, NTFS hard and symbolic links, and Quick Open record to allow large archives to be opened faster.
The RAR5 file format removed comments for each file, authenticity verification, and specialized compression algorithms for text and multimedia files. RAR5 also changed the file name for split volumes from "archivename.rNN" to "archivename.partNN.rar".
Features
- Creation of packed RAR or ZIP archives.
- Unpacking of ARJ, BZIP2, CAB, GZ, ISO, JAR, LHA, RAR, TAR, UUE, XZ, Z, ZIP, ZIPX, 7z, 001 archives, as well as EXE files containing these archive formats
- Checksum verification for ARJ, BZIP2, CAB, GZ, BZIP2, RAR, XZ, ZIP and 7z archives
- Multithreaded CPU compression and decompression
- Support for maximum file size of 16 EiB, about 1.8 × 1019 bytes or 18 million TB
- Compression dictionary from 1 MiB to 1 GiB
- Options, enabled by default, to optimise compression for executables for x86 processors and the obsolete 64-bit Itanium, and delta compression.
- Optional 256-bit BLAKE2 file hash can replace default 32-bit CRC32 file checksum
- Optional encryption using AES with a 256-bit key in CBC mode, using key derivation function based on PBKDF2 using HMAC-SHA256
- Optional data redundancy is provided in the form of Reed–Solomon recovery records and recovery volumes, allowing reconstruction of damaged archives
- Optional "quick open record" to open RAR files faster
- Ability to create multi-volume archives
- Ability to create self-extracting files
- Support for advanced NTFS file system options, such as NTFS hard and symbolic links
- Support for maximum path length up to 2048 characters
- Optional archive comment
- Optional file time stamp preservation: creation, last access, high precision modification times
- Optional file deduplication
License
Although archiving with the RAR format is proprietary, RARLAB supplies as copyrighted freeware the C++ source code of the current UnRAR unpacker, with a license allowing it to be used in any software, thus enabling others to produce software capable of unpacking, but not creating, RAR archives.
RAR for Android is free of charge. It displays advertisements; for a payment they can be disabled. A license for WinRAR does not provide ad-suppression for RAR for Android.
Security
In February 2019, a major security vulnerability in the unacev2.dll library which is used by WinRAR to decompress ACE archives was discovered. Consequently, WinRAR dropped the support for the ACE format from version 5.70.Self-extracting archives created with versions before 5.31 are vulnerable to DLL hijacking: they may load and use DLLs named UXTheme.dll, RichEd32.dll and RichEd20.dll if they are in the same folder as the executable file.
It was widely reported that WinRAR v5.21 and earlier had a remote code execution vulnerability which could allow a remote attacker to insert malicious code into a self-extracting executable file being created by a user, "putting over 500 million users of the software at risk". However, examination of the claim revealed that, while the vulnerability existed, the result was merely an SFX which delivered its payload when executed; published responses dismissed the threat, one saying "If you can find suckers who will trust a.exe labelled as self-extracting archive... then you can trick them into running your smuggled JavaScript".
History
Versions
- Command line RAR and UNRAR were first released in autumn 1993.
- Early development version WinRAR 1.54b was released in 1995 as Windows 3.x software.
- 3.00 : the new RAR3 archive format is implemented. The new archives cannot be managed by older versions of WinRAR.
- 3.41 : adds support for Linux.Z archives like GZIP and BZIP2. New options include storing entire file paths and restoring compressed NTFS files.
- 3.50 : adds support for interface skins and Windows XP Professional x64 Edition.
- 3.60 : adds multithreaded version of the compression algorithm, which improves compression speed on systems with multiple dual-core or hyper-threading-enabled CPUs.
- 3.80 : adds support for ZIP archives, which contain Unicode file names in UTF-8.
- 3.90 : adds support for the x86-64 architecture and Windows 7. Multithreaded support is enhanced.
- 3.91 is the last release that supports Valencian.
- 3.92 is the last release that supports Serbian Cyrillic and Serbian Latin.
- 4.00 : decompression is sped up by up to 30%. Windows 98, Windows ME, and Windows NT are no longer supported; the minimum Windows version required is Windows 2000.
- 4.10 : removes all ZIP limitations now allowing unlimited number of files and archive size. WinRAR now also allows creation of multivolume ZIP files. ZIP archives now include Unicode file names.
- 4.20 : compression speed in SMP mode is increased significantly, but this improvement was made at the expense of increased memory usage. ZIP compression now uses SMP as well. The default SMP mode cannot handle text; text compression is significantly worse unless additional switches are used. Also, Windows 2000 compatibility was removed.
- 5.00 : the RAR5 archive format is implemented. RAR5 compressed archives cannot be managed by old versions of WinRAR. The RAR 5 format improves multi-core processor utilization, and adds a larger dictionary size of up to 1 GiB with 64-bit WinRAR. Special optional compression algorithms optimized for RGB bitmaps, raw audio files, Itanium executables, and plain text, which were supported by earlier versions, are supported only in the older RAR format, not RAR5. Optional optimized compression of x86 executables and delta compression are supported in both file formats.
- 5.50 : adds support for a master password which can be used to encrypt passwords stored in WinRAR. The default RAR format is changed to version 5. Adds support for decompressing Lzip archives; adds support for high precision file dates, longer file names and larger file sizes for TAR archives.
- 5.60 : repairing of protected RAR5 archives was improved. Automatic detection of the encoding of ZIP archive comments. Recognition of GZIP files with arbitrary preceding data as an actual GZIP archive.
- 5.70 : removes support for ACE archives decompression due to major security vulnerabilities in the unacev2.dll library.
Operating systems support
- RAR 2.50 for MS-DOS is the last version that supports MS-DOS and OS/2 on 16-bit x86 CPUs.
- RAR 3.93 for MS-DOS is the last version for MS-DOS and OS/2 on IA-32 CPUs. It supports file names longer than the MS-DOS standard of 8.3 characters, in a Windows DOS box, and uses the RSX DPMI extender.
- WinRAR 3.93 is the last version that supports Windows 95, 98, ME, and NT 4.0. RAR for Pocket PC 3.93 is the last version for Windows Mobile.
- WinRAR 4.11 is the last version that supports Windows 2000.