NAME
hashdeep - Compute, compare, or audit multiple message digests
SYNOPSIS
hashdeep -V | -h
hashdeep [-c <alg1>[,<alg2>]] [-k <file>] [-i <size>] [-amxwMXrespblvv]
[FILES]
DESCRIPTION
Computes multiple hashes, or message digests, for any number of files
while optionally recursively digging through the directory structure.
By default the program computes MD5 and SHA-256 hashes, equivalent to
-c md5,sha256. Can also take a list of known hashes and display the
filenames of input files whose hashes either do or do not match any of
the known hashes. Can also use a list of known hashes to audit a set
of FILES. Errors are reported to standard error. If no FILES are
specified, reads from standard input.
-c <alg1>[,<alg2>...]
Computation mode. Compute hashes of FILES using the algorithms
specified. Legal values are md5, sha1, sha256, tiger, and
whirlpool.
-k Load a file of known hashes. This flag is required when using
any of the matching or audit modes (i.e. -m, -x, -M, -X, or -a)
This flag may be used more than once to add multiple sets of
known hashes.
Loading sets with different hash algorithms can sometimes
generate spurrious hash collisions. For example, let’s say we
have two hash sets, A and B, which have some overlapping files.
For example, the file /usr/bin/bad is in both sets. In A we’ve
recorded the MD5 and SHA-256. In B we’ve recorded the MD5,
SHA-1, and SHA-256. Because these two records are different,
they will both be loaded. When the program computes all three
hashes and compares them to the set of knowns, we will get an
exact match from the record in B and a collision from the record
in A.
-a Audit mode. Each input file is compared against the set of
knowns. An audit is said to pass if each input file is matched
against exactly one file in set of knowns. Any collisions, new
files, or missing files will make the audit fail. Using this
flag alone produces a message, either "Audit passed" or "Audit
Failed". Use the verbose modes, -v, for more details. Using -v
prints the number of files in each category. Using -v a second
time prints any discrepancies. Using -v a third time prints the
results for every file examined and every known file.
Due to limitations in the program, any filenames with Unicode
characters will appear to have moved during an audit. See the
section "UNICODE SUPPORT" below.
-m Positive matching, requires at least one use of the -k flag.
The input files are examined one at a time, and only those files
that match the list of known hashes are output. The only
acceptable format for known hashes is the output of previous
hashdeep runs.
If standard input is used with the -m flag, displays "stdin" if
the input matches one of the hashes in the list of known hashes.
If the hash does not match, the program displays no output.
This flag may not be used in conjunction with the -x, -X, or -a
flags. See the section "UNICODE SUPPORT" below.
-x Negative matching. Same as the -m flag above, but does negative
matching. That is, only those files NOT in the list of known
hashes are displayed.
This flag may not be used in conjunction with the -m, -M, or -a
flags. See the section "UNICODE SUPPORT" below.
-w When used with positive matching modes (-m,-M) displays the
filename of the known hash that matched the input file. See the
section "UNICODE SUPPORT" below.
-M and -X
Same as -m and -x above, but displays the hash for each file
that does (or does not) match the list of known hashes.
-r Enables recursive mode. All subdirectories are traversed. Please
note that recursive mode cannot be used to examine all files of
a given file extension. For example, calling hashdeep -r *.txt
will examine all files in directories that end in .txt.
-e Displays a progress indicator and estimate of time remaining for
each file being processed. Time estimates for files larger than
4GB are not available on Windows. This mode may not be used with
th -p mode.
-i <size>
Size threshold mode. Only hash files smaller than the given the
threshold. Sizes may be specified using multiplers b,k,m,g,t,p,
and e.
-s Enables silent mode. All error messages are supressed.
-p Piecewise mode. Breaks files into chunks before hashing. Chunks
may be specified using multiplers b,k,m,g,t,p, and e. (Never let
it be said that the author didnâ
-b Enables bare mode. Strips any leading directory information from
displayed filenames. This flag may not be used in conjunction
with the -l flag.
-l Enables relative file paths. Instead of printing the absolute
path for each file, displays the relative file path as indicated
on the command line. This flag may not be used in conjunction
with the -b flag.
-v Enables verbose mode. Use again to make the program more
verbose. This mostly changes the behvaior of the audit mode,
-a.
-h Show a help screen and exit.
-V Show the version number and exit.
UNICODE SUPPORT
As of version 2.0 the program can process input files with Unicode
characters in their filenames on Windows systems. In the program’s
output, however, each Unicode character is represented with a question
mark (?). Note that Unicode characters are not supported in the files
containing known hashes. You can specify a file of known hashes that
has Unicode characters in its name by using tab completition or an
asterisk (e.g. hashdeep -mk *.txt where there is only one file with a
.txt extension).
RETURN VALUE
Returns zero on success, one on error.
AUTHOR
hashdeep was written by Jesse Kornblum, md5deep [at] jessekornblum
[dot] com.
KNOWN ISSUES
Using the -r flag cannot be used to recursively process all files of a
given extension in a directory. This is a feature, not a bug. If you
need to do this, use the find(1) command.
The program will fail if you attempt to compare 2^64 or more input
files against a set of known files.
REPORTING BUGS
We take all bug reports very seriously. Any bug that jeopardizes the
forensic integrity of this program could have serious consequenses on
people’s lives. When submitting a bug report, please include a
description of the problem, how you found it, and your contact
information.
Send bug reports to: md5deep [at] jessekornblum [dot] com
COPYRIGHT
This program is a work of the US Government. In accordance with 17 USC
105, copyright protection is not available for any work of the US
Government. This program is PUBLIC DOMAIN. Portions of this program
contain code that is licensed under the terms of the General Public
License (GPL). Those portions retain their original copyright and
license. See the file COPYING for more details.
There is NO warranty for this program; not even for MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.
SEE ALSO
More information and installation instructions can be found in the
README file. Current versions of both documents can be found on the
project homepage: http://md5deep.sourceforge.net/
The MD5 specification, RFC 1321, is available at
http://www.ietf.org/rfc/rfc1321.txt
The SHA-1 specification, RFC 3174, is available at
http://www.faqs.org/rfcs/rfc31.html
The SHA-256 specification, FIPS 180-2, is available at
http://csrc.nist.gov/publications/fips/fips180-2/fips180-2.pdf
The Tiger specification is available at
http://www.cs.technion.ac.il/~biham/Reports/Tiger/
The Whirlpool specification is available at
http://planeta.terra.com.br/informatica/paulobarreto/WhirlpoolPage.html