ReHash - A console-based hash calculator

• Download source code - 276 Kb
• Download Win32 executable - 167 Kb

Contents

• Introduction
• Supported algorithms
• Usage
• Thanks / acknowledgements

Introduction

ReHash is a free, open source console-based hash calculator.

You can disable hash algorithms selectively per command-line if you don't need or like them, you can choose if you want to use recursive directory scanning or not.

This tool is ideal for webmasters who wish to provide their users hash values of their (downloadable) files. The complete hashing process can be automated by using a shell/batch script. No additional user interaction is needed (i.e. the program won't ask for anything, it's just using the command-line).

ReHash is distributed under the terms of the GNU General Public License v2.

Supported algorithms

The current version of ReHash supports the following hash algorithms:

Algorithm	Standard	Inventor	Hash Digest Size
CRC-16			16 bits
CRC-16-CCITT			16 bits
CRC-32	ANSI X3.66, FIPS PUB 71		32 bits
FCS-16			16 bits
FCS-32			32 bits
GHash (GHash-32-3, GHash-32-5)	-	-	32 bits
GOST-Hash	R 34.11-94		256 bits
HAVAL (5 passes, 256 bits)		Zheng, Pieprzyk, Seberry	256 bits
MD2	RFC 1319	Rivest	128 bits
MD4	RFC 1320	Rivest	128 bits
MD5	RFC 1321	Rivest	128 bits
SHA-1	FIPS PUB 180-1	NIST/NSA	160 bits
SHA-2 (SHA256/SHA384/SHA512)		NIST/NSA	256/384/512 bits
SizeHash-32	-	-	32 bits
Tiger		Anderson, Biham	192 bits

Usage

rehash.exe [options] filespec [> outputfile]

The command-line is parsed from the left to the right. So if you execute ReHash like this:

rehash.exe -all -none *.*

it will output nothing, because you first activate all algorithms and then deactivate them all.


Some usage examples:

Hash all INI files in C:\Windows (including subdirectories) using all hash algorithms:

rehash.exe C:\Windows\*.ini

Hash all INI files in C:\Windows (excluding subdirectories) using all hash algorithms:

rehash.exe -norecur C:\Windows

Hash all BAT files on C:\ (including subdirectories) using only MD5 and SHA-1 (remember command-line is parsed from the left to the right):

rehash.exe -none -md5 -sha1 C:\*.bat

Hash all files in C:\Temp (excluding subdirectories) using only the GOST algorithm:

rehash.exe -norecur -none -gost C:\Temp\*

Hash all ZIP files in C:\homepage (including subdirectories) using only the MD5 algorithm and output the hashes to C:\homepage\downloads\hashes.txt:

rehash.exe -none -md5 C:\homepage\*.zip > C:\homepage\downloads\hashes.txt

All options:

Option	Description
-help / -h / -?/ -version / -v	Print some information about ReHash.
-fullpath / -f	Output the full paths of hashed files.
-nopath	Just output the filenames of hashed files, not the full paths to the files.
-rcrsv / -recur / -r	Recursive scanning. Scan all files in the specified path including files in subdirectories.
-norcrsv / -norecur	Disable recursive scanning. Scan only the files in the specified path not including subdirectories.
-all / -a	Enable all algorithms.
-none / -n	Disable all algorithms.
-crc16 / -nocrc16	Enable/disable the CRC-16 algorithm.
-crc16c / -nocrc16c	Enable/disable the CRC-16-CCITT algorithm.
-crc32 / -nocrc32	Enable/disable the CRC-32 algorithm.
-fcs16 / -nofcs16	Enable/disable the FCS-16 algorithm.
-fcs32 / -nofcs32	Enable/disable the FCS-32 algorithm.
-ghash3 / -noghash3	Enable/disable the GHash-3 algorithm.
-ghash5 / -noghash5	Enable/disable the GHash-5 algorithm.
-gost / -nogost	Enable/disable the GOST-Hash algorithm.
-haval / -nohaval	Enable/disable the HAVAL-5-256 algorithm.
-md2 / -nomd2	Enable/disable the MD2 algorithm.
-md4 / -nomd4	Enable/disable the MD4 algorithm.
-md5 / -nomd5	Enable/disable the MD5 algorithm.
-sha1 / -nosha1	Enable/disable the SHA-1 algorithm.
-sha256 / -nosha256	Enable/disable the SHA-256 algorithm.
-sha384 / -nosha384	Enable/disable the SHA-384 algorithm.
-sha512 / -nosha512	Enable/disable the SHA-512 algorithm.
-size32 / -nosize32	Enable/disable the Size-32 algorithm (simply the byte-count of the message).
-tiger / -notiger	Enable/disable the TIGER algorithm.

Thanks / acknowledgements

Thanks to (no particular order):

• Markku-Juhani O. Saarinen - GOST-Hash implementation
• Yuliang Zheng - HAVAL implementation
• Wei Dai - implementations of various algorithms
• Dr Brian Gladman - SHA-1/SHA-2 implementation
• Tom St Denis - Tiger implementation

History

• 12 April 2003 - v1.0
  First public release