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| Line 1: |
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| − | RAR Archives ('''R'''oshal '''AR'''chive file format) is a proprietary format for storing information created by Eugene Roshal. The format is currently handled by Alexander Roshal, Eugene's brother.
| + | Graphical representation of the relationship between tables in the places.sqlite database file. Picture was gathered from irc.mozilla.org#places on April 15, 2008 |
| − | | + | |
| − | ==Format==
| + | |
| − | The file has the magic number of:
| + | |
| − | <pre>0x 52 61 72 21 1A 07 00</pre>
| + | |
| − | which is a break down of the following to describe an Archive Header:
| + | |
| − | :* 0x6152 - HEAD_CRC
| + | |
| − | :* 0x72 - HEAD_TYPE
| + | |
| − | :* 0x1a21 - HEAD_FLAGS
| + | |
| − | :* 0x0007 - HEAD_SIZE
| + | |
| − | | + | |
| − | ----
| + | |
| − | ===RAR File Format===
| + | |
| − | | + | |
| − | Each Block has the following fields
| + | |
| − | {| class="wikitable"
| + | |
| − | |+ Block Fields
| + | |
| − | ! Name
| + | |
| − | ! Size (bytes)
| + | |
| − | ! Description
| + | |
| − | |-
| + | |
| − | | HEAD_CRC
| + | |
| − | | 2
| + | |
| − | | CRC of total block or block part
| + | |
| − | |-
| + | |
| − | | HEAD_TYPE
| + | |
| − | | 1
| + | |
| − | | Block type
| + | |
| − | |-
| + | |
| − | | HEAD_FLAGS
| + | |
| − | | 2
| + | |
| − | | Block flags
| + | |
| − | |-
| + | |
| − | | HEAD_SIZE
| + | |
| − | | 2
| + | |
| − | | Block size
| + | |
| − | |-
| + | |
| − | | ADD_SIZE
| + | |
| − | | 4
| + | |
| − | | Optional field - added block size
| + | |
| − | |}
| + | |
| − | | + | |
| − | ----
| + | |
| − | There are certain block types
| + | |
| − | | + | |
| − | {| class="wikitable"
| + | |
| − | |+ Block Types
| + | |
| − | ! Head Type Signifier
| + | |
| − | ! Description
| + | |
| − | |-
| + | |
| − | | HEAD_TYPE=0x72
| + | |
| − | | marker block
| + | |
| − | |-
| + | |
| − | | HEAD_TYPE=0x73
| + | |
| − | | archive header
| + | |
| − | |-
| + | |
| − | | HEAD_TYPE=0x74
| + | |
| − | | file header
| + | |
| − | |-
| + | |
| − | | HEAD_TYPE=0x75
| + | |
| − | | old style comment header
| + | |
| − | |-
| + | |
| − | | HEAD_TYPE=0x76
| + | |
| − | | old style authenticity information
| + | |
| − | |-
| + | |
| − | | HEAD_TYPE=0x77
| + | |
| − | | old style subblock
| + | |
| − | |-
| + | |
| − | | HEAD_TYPE=0x78
| + | |
| − | | old style recovery record
| + | |
| − | |-
| + | |
| − | | HEAD_TYPE=0x79
| + | |
| − | | old style authenticity information
| + | |
| − | |-
| + | |
| − | | HEAD_TYPE=0x7a
| + | |
| − | | subblock
| + | |
| − | |}
| + | |
| − | | + | |
| − | ----
| + | |
| − | ===Block Formats===
| + | |
| − | There are several block formats that are contained within a RAR file. They are Marker Block, Archive Header, and File Header.
| + | |
| − | | + | |
| − | | + | |
| − | ----
| + | |
| − | ====Marker Block (MARK_HEAD)====
| + | |
| − | | + | |
| − | {| class="wikitable"
| + | |
| − | |+ MARK_HEAD
| + | |
| − | ! Field Name
| + | |
| − | ! Size (bytes)
| + | |
| − | ! Possibilities
| + | |
| − | |-
| + | |
| − | | HEAD_CRC
| + | |
| − | | 2
| + | |
| − | | Always 0x6152
| + | |
| − | |-
| + | |
| − | | HEAD_TYPE
| + | |
| − | | 1
| + | |
| − | | Header type: 0x72
| + | |
| − | |-
| + | |
| − | | HEAD_FLAGS
| + | |
| − | | 2
| + | |
| − | | Always 0x1a21
| + | |
| − | |-
| + | |
| − | | HEAD_SIZE
| + | |
| − | | 2
| + | |
| − | | Block size = 0x0007
| + | |
| − | |}
| + | |
| − | | + | |
| − | * Note: the marker block is considered a fixed byte sequence (AKA, magic number) of: 0x52 0x61 0x72 0x21 0x1a 0x07 0x00 (which is seen as 'Rar! ')
| + | |
| − | | + | |
| − | ----
| + | |
| − | ====Archive Header (MAIN_HEAD)====
| + | |
| − | | + | |
| − | {| class="wikitable"
| + | |
| − | |+ MAIN_HEAD
| + | |
| − | ! Field Name
| + | |
| − | ! Size (bytes)
| + | |
| − | ! Description
| + | |
| − | |-
| + | |
| − | | HEAD_CRC
| + | |
| − | | 2
| + | |
| − | | CRC of fields HEAD_TYPE to RESERVED2
| + | |
| − | |-
| + | |
| − | | HEAD_TYPE
| + | |
| − | | 1
| + | |
| − | | Header Type: 0x73
| + | |
| − | |-
| + | |
| − | | HEAD_FLAGS
| + | |
| − | | 2
| + | |
| − | | Bit Flags (Please see 'Bit Flags for MAIN_HEAD' table for all possibilities).
| + | |
| − | |-
| + | |
| − | | HEAD_SIZE
| + | |
| − | | 2
| + | |
| − | | Archive header total size including archive comments
| + | |
| − | |-
| + | |
| − | | RESERVED1
| + | |
| − | | 2
| + | |
| − | | RESERVED
| + | |
| − | |-
| + | |
| − | | RESERVED2
| + | |
| − | | 4
| + | |
| − | | RESERVED
| + | |
| − | |}
| + | |
| − | | + | |
| − | | + | |
| − | {| class="wikitable"
| + | |
| − | |+ Bit Flags for MAIN_HEAD
| + | |
| − | ! Flag (0x)
| + | |
| − | ! Description
| + | |
| − | |-
| + | |
| − | | 0001
| + | |
| − | | Volume attribute (archive volume)
| + | |
| − | |-
| + | |
| − | | 0002
| + | |
| − | | Archive comment present RAR 3.x uses the separate comment block and does not set this flag.
| + | |
| − | |-
| + | |
| − | | 0004
| + | |
| − | | Archive lock attribute
| + | |
| − | |-
| + | |
| − | | 0008
| + | |
| − | | Solid attribute (solid archive)
| + | |
| − | |-
| + | |
| − | | 0010
| + | |
| − | | New volume naming scheme ('volname.partN.rar')
| + | |
| − | |-
| + | |
| − | | 0020
| + | |
| − | | Authenticity information present RAR 3.x does not set this flag.
| + | |
| − | |-
| + | |
| − | | 0040
| + | |
| − | | Recovery record present
| + | |
| − | |-
| + | |
| − | | 0080
| + | |
| − | | Block headers are encrypted
| + | |
| − | |-
| + | |
| − | | 0100
| + | |
| − | | First volume (set only by RAR 3.0 and later)
| + | |
| − | |}
| + | |
| − | * Other bits in HEAD_FLAGS are reserved for internal use.
| + | |
| − | ----
| + | |
| − | | + | |
| − | ====File Header (File in Archive)====
| + | |
| − | {| class="wikitable"
| + | |
| − | |+ File Header
| + | |
| − | ! Field Name
| + | |
| − | ! Size (bytes)
| + | |
| − | ! Description
| + | |
| − | |-
| + | |
| − | | HEAD_CRC
| + | |
| − | | 2
| + | |
| − | | CRC of fields from HEAD_TYPE to FILEATTR and file name
| + | |
| − | |-
| + | |
| − | | HEAD_TYPE
| + | |
| − | | 1
| + | |
| − | | Header Type: 0x74
| + | |
| − | |-
| + | |
| − | | HEAD_FLAGS
| + | |
| − | | 2
| + | |
| − | | Bit Flags (Please see 'Bit Flags for File in Archive' table for all possibilities)
| + | |
| − | |-
| + | |
| − | | HEAD_SIZE
| + | |
| − | | 2
| + | |
| − | | File header full size including file name and comments
| + | |
| − | |-
| + | |
| − | | PACK_SIZE
| + | |
| − | | 4
| + | |
| − | | Compressed file size
| + | |
| − | |-
| + | |
| − | | UNP_SIZE
| + | |
| − | | 4
| + | |
| − | | Uncompressed file size
| + | |
| − | |-
| + | |
| − | | HOST_OS
| + | |
| − | | 1
| + | |
| − | | Operating system used for archiving (See the 'Operating System Indicators' table for the flags used)
| + | |
| − | |-
| + | |
| − | | FILE_CRC
| + | |
| − | | 4
| + | |
| − | | File CRC
| + | |
| − | |-
| + | |
| − | | FTIME
| + | |
| − | | 4
| + | |
| − | | Date and time in standard MS DOS format
| + | |
| − | |-
| + | |
| − | | UNP_VER
| + | |
| − | | 1
| + | |
| − | | RAR version needed to extract file (Version number is encoded as 10 * Major version + minor version.)
| + | |
| − | |-
| + | |
| − | | METHOD
| + | |
| − | | 1
| + | |
| − | | Packing method (Please see 'Packing Method' table for all possibilities
| + | |
| − | |-
| + | |
| − | | NAME_SIZE
| + | |
| − | | 2
| + | |
| − | | File name size
| + | |
| − | |-
| + | |
| − | | ATTR
| + | |
| − | | 4
| + | |
| − | | File attributes
| + | |
| − | |-
| + | |
| − | | HIGH_PACK_SIZE
| + | |
| − | | 4
| + | |
| − | | High 4 bytes of 64-bit value of compressed file size. Optional value, presents only if bit 0x100 in HEAD_FLAGS is set.
| + | |
| − | |-
| + | |
| − | | HIGH_UNP_SIZE
| + | |
| − | | 4
| + | |
| − | | High 4 bytes of 64-bit value of uncompressed file size. Optional value, presents only if bit 0x100 in HEAD_FLAGS is set.
| + | |
| − | |-
| + | |
| − | | FILE_NAME
| + | |
| − | | NAME_SIZE bytes
| + | |
| − | | File name - string of NAME_SIZE bytes size
| + | |
| − | |-
| + | |
| − | | SALT
| + | |
| − | | 8
| + | |
| − | | present if (HEAD_FLAGS & 0x400) != 0
| + | |
| − | |-
| + | |
| − | | EXT_TIME
| + | |
| − | | variable size
| + | |
| − | | present if (HEAD_FLAGS & 0x1000) != 0
| + | |
| − | |}
| + | |
| − | | + | |
| − | *other new fields may appear here.
| + | |
| − | | + | |
| − | | + | |
| − | {| class="wikitable"
| + | |
| − | |+ Bit Flags for Files in Archive
| + | |
| − | ! Flag (0x)
| + | |
| − | ! Description
| + | |
| − | |-
| + | |
| − | | 01
| + | |
| − | | File continued from previous volume
| + | |
| − | |-
| + | |
| − | | 02
| + | |
| − | | File continued in next volume
| + | |
| − | |-
| + | |
| − | | 04
| + | |
| − | | File encrypted with password
| + | |
| − | |-
| + | |
| − | | 08
| + | |
| − | | File comment present. RAR 3.x uses the separate comment block and does not set this flag.
| + | |
| − | |-
| + | |
| − | | 10
| + | |
| − | | Information from previous files is used (solid flag) (for RAR 2.0 and later)
| + | |
| − | |-
| + | |
| − | | Dictionary bits 7 6 5 (for RAR 2.0 and later)
| + | |
| − | | Please see the 'Dictionary Bits' table for this descriptions
| + | |
| − | |-
| + | |
| − | | 100
| + | |
| − | | HIGH_PACK_SIZE and HIGH_UNP_SIZE fields are present. These fields are used to archive only very large files (larger than 2Gb), for smaller files these fields are absent.
| + | |
| − | |-
| + | |
| − | | 200
| + | |
| − | | FILE_NAME contains both usual and encoded Unicode name separated by zero. In this case NAME_SIZE field is equal to the length of usual name plus encoded Unicode name plus 1. If this flag is present, but FILE_NAME does not contain zero bytes, it means that file name is encoded using UTF-8.
| + | |
| − | |-
| + | |
| − | | 400
| + | |
| − | | The header contains additional 8 bytes after the file name, which are required to increase encryption security (so called 'salt').
| + | |
| − | |-
| + | |
| − | | 800
| + | |
| − | | Version flag. It is an old file version, a version number is appended to file name as ';n'.
| + | |
| − | |-
| + | |
| − | | 1000
| + | |
| − | | Extended time field present.
| + | |
| − | |-
| + | |
| − | | 8000
| + | |
| − | | This bit always is set, so the complete block size is HEAD_SIZE + PACK_SIZE (and plus HIGH_PACK_SIZE, if bit 0x100 is set)
| + | |
| − | |}
| + | |
| − | | + | |
| − | {| class="wikitable"
| + | |
| − | |+Dictionary Bits
| + | |
| − | ! Bits (7 6 5)
| + | |
| − | ! Description
| + | |
| − | ! Size (KB)
| + | |
| − | |-
| + | |
| − | | 0 0 0
| + | |
| − | | Dictionary Size
| + | |
| − | | 64
| + | |
| − | |-
| + | |
| − | | 0 0 1
| + | |
| − | | Dictionary Size
| + | |
| − | | 128
| + | |
| − | |-
| + | |
| − | | 0 1 0
| + | |
| − | | Dictionary Size
| + | |
| − | | 256
| + | |
| − | |-
| + | |
| − | | 0 1 1
| + | |
| − | | Dictionary Size
| + | |
| − | | 512
| + | |
| − | |-
| + | |
| − | | 1 0 0
| + | |
| − | | Dictionary Size
| + | |
| − | | 1024
| + | |
| − | |-
| + | |
| − | | 1 0 1
| + | |
| − | | Dictionary Size
| + | |
| − | | 2048
| + | |
| − | |-
| + | |
| − | | 1 1 0
| + | |
| − | | Dictionary Size
| + | |
| − | | 4096
| + | |
| − | |-
| + | |
| − | | 1 1 1
| + | |
| − | | file is a directory
| + | |
| − | | N/A
| + | |
| − | |}
| + | |
| − | | + | |
| − | {| class="wikitable"
| + | |
| − | |+ Operating System Indicators
| + | |
| − | ! Byte Indicator
| + | |
| − | ! Operating System
| + | |
| − | |-
| + | |
| − | | 0
| + | |
| − | | MS DOS
| + | |
| − | |-
| + | |
| − | | 1
| + | |
| − | | OS/2
| + | |
| − | |-
| + | |
| − | | 2
| + | |
| − | | Windows
| + | |
| − | |-
| + | |
| − | | 3
| + | |
| − | | Unix
| + | |
| − | |-
| + | |
| − | | 4
| + | |
| − | | Mac OS
| + | |
| − | |-
| + | |
| − | | 5
| + | |
| − | | BeOS
| + | |
| − | |}
| + | |
| − | ----
| + | |
| − | | + | |
| − | | + | |
| − | ==Metadata==
| + | |
| − | | + | |
| − | | + | |
| − | | + | |
| − | ==Sub-formats==
| + | |
| − | | + | |
| − | The RAR format is comprised of many sub-formats that have changed over the years. The different formats and their descriptions are as follows:
| + | |
| − | :* 1.3 (Does not have the RAR! signature)
| + | |
| − | :** There is difficulty finding information regarding this sub-format. Please update if you know something.
| + | |
| − | :* 1.5
| + | |
| − | :** Utilizes a proprietary compression method that is not available to the public.
| + | |
| − | :** Considered the root model of subsequent formats.
| + | |
| − | :** A detailed list of information can be found [http://www.win-rar.com/index.php?id=24&kb_article_id=162 here].
| + | |
| − | :* 2.0
| + | |
| − | :** Utilizes a proprietary compression method that is not available to the public.
| + | |
| − | :** Based off of version 1.5 of the RAR file format.
| + | |
| − | :* 3.0
| + | |
| − | :** Utilizes the [http://en.wikipedia.org/wiki/Prediction_by_Partial_Matching PPMII] and [http://en.wikipedia.org/wiki/LZ77_and_LZ78 Lempel-Ziv (LZSS)]] algorithms.
| + | |
| − | :** Encryption now uses cipher block chaining (CBC) instead of Advanced Encryption Standard (AES).
| + | |
| − | :** Based off of version 1.5 of the RAR file format.
| + | |
| − | | + | |
| − | | + | |
| − | | + | |
| − | ==Software==
| + | |
| − | | + | |
| − | This only way to create a RAR file is using the [http://www.rarlab.com/ Winrar software]. There are several implementations of the process to open a RAR file (commonly known as the "unrar" process). Some of them are:
| + | |
| − | | + | |
| − | ;unrarLib
| + | |
| − | | + | |
| − | :* RAR file unarchiver written in C
| + | |
| − | :* Easy implementation with a header file and the source code file
| + | |
| − | :* [http://www.unrarlib.org/ Information Link]
| + | |
| − | | + | |
| − | ;WinRAR
| + | |
| − | | + | |
| − | :* Only software that can create and open a RAR file
| + | |
| − | :* Distributed by a proprietary license
| + | |
| − | :* [http://www.rarlab.com/download.htm WinRAR executable for Windows]
| + | |
| − | | + | |
| − | ;UnRAR
| + | |
| − | | + | |
| − | :* Created by Eugene Roshal for opening up RAR files only
| + | |
| − | :* May not be used to reverse engineer the RAR file format and create RAR files
| + | |
| − | :* Source code provided for people to implement/integrate methods of opening RAR files
| + | |
| − | :* Additionally, implementations of UnRAR are available for a plethora of operating systems
| + | |
| − | :* [http://www.rarlab.com/rar_add.htm Download Link]
| + | |
| − | | + | |
| − | ;The Unarchiver
| + | |
| − | | + | |
| − | :* Utility made for Mac OSX to open a multitude of files, including RAR files
| + | |
| − | :* Very handy for dealing with multiple file types
| + | |
| − | :* [http://code.google.com/p/theunarchiver/downloads/list Source Code Download]
| + | |
| − | :* [http://unarchiver.c3.cx/ Information Website]
| + | |
| − | | + | |
| − | ;7-Zip
| + | |
| − | | + | |
| − | :* Utility made for Windows applications to open a multitude of files, including RAR files
| + | |
| − | :* [http://www.7-zip.org/download.html Download Link]
| + | |
| − | | + | |
| − | | + | |
| − | There is a lot more software to open RAR files, but have been omitted due to redundancy.
| + | |
| − | ==See Also==
| + | |
| − | * [http://en.wikipedia.org/wiki/RAR Wikipedia: RAR]
| + | |
| − | * [http://acritum.com/winrar/rar-format RAR File Format Information]
| + | |
| − | * RAR File Format Technical Information for Version 4.11 [[File:RARFileStructure.txt]]
| + | |
| − | | + | |
| − | [[Category:File Formats]]
| + | |
Graphical representation of the relationship between tables in the places.sqlite database file. Picture was gathered from irc.mozilla.org#places on April 15, 2008
