md5deep

Tracker: Feature Requests

5 crc32 - ID: 2890821

Last Update: Comment added ( richrumble )

Details:

Were looking to utilize hashdeep/md5deep in our File Integrity Monitor,
would it be possible to add crc32 hash's? We've noticed that we can scan
for changes much faster using programs that use crc32 hash's, and we can
work out possible hash collisions using other algo's (md5/sha) when
duplicate crc32 hash's are detected. I think crc32 could greatly speed up
searching for file changes when dealing with entire harddrives/partitions.
Thanks!
Keep up the good work!
-rich

Submitted:

RichRumble ( richrumble ) - 2009-11-02 17:26

Priority:

Status:

Open

Resolution:

None

Assigned:

Nobody/Anonymous

Category:

algorithm to add

Group:

None

Visibility:

Public

Comments ( 2 )

Date: 2009-11-03 17:02 Sender: richrumble It's the PNG/Mpeg-2/ but that is different than the Ethernet version, but the wikipedia entry I believe is wrong to list the 802.3 along side the png/mp2/zip crc32... It seems to also be known as crc32b, the tables they use are different, php source code has the differences in php-5.2.11\ext\hash\php_hash_crc32_tables.h The php crc32b seems to give the same results that I've come to expect from most other crc32 checkers I've used. I'm told by a developer of one such tool, hashtab, that the crc32 source he used was from CryptoPP, and he used that, but had to reverse the bytes from the cryptopp digest however. http://www.cryptopp.com/docs/ref/crc_8h-source.html I hope that is enough info... using php's crc32b the hash of a text file with "Lorem Ipsum" (no quotes) inside it hash's to: 358AD45D -rich
Date: 2009-11-03 14:57 Sender: jessekornblum Which version of CRC32 are you looking for? There are several! See http://en.wikipedia.org/wiki/Cyclic_redundancy_check for a list.

Date: 2009-11-03 17:02
Sender: richrumble

It's the PNG/Mpeg-2/ but that is different than the Ethernet version, but
the wikipedia entry I believe is wrong to list the 802.3 along side the
png/mp2/zip crc32...
It seems to also be known as crc32b, the tables they use are different,
php source code has the differences in
php-5.2.11\ext\hash\php_hash_crc32_tables.h
The php crc32b seems to give the same results that I've come to expect
from most other crc32 checkers I've used. I'm told by a developer of one
such tool, hashtab, that the crc32 source he used was from CryptoPP, and he
used that, but had to reverse the bytes from the cryptopp digest however.
http://www.cryptopp.com/docs/ref/crc_8h-source.html
I hope that is enough info... using php's crc32b the hash of a text file
with
"Lorem Ipsum" (no quotes) inside it hash's to: 358AD45D
-rich

Date: 2009-11-03 14:57
Sender: jessekornblum

Which version of CRC32 are you looking for? There are several! See
http://en.wikipedia.org/wiki/Cyclic_redundancy_check for a list.

md5deep

Tracker: Feature Requests

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