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Questions tagged [checksum]

A checksum is a value created from a binary file that can be used to validate its authenticity and integrity. An example of a checksum is MD4, MD5 and SHA-1.

4
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1answer
321 views

Why is this SSD returning inconsistent data, why doesn't the backup image file match the checksum?

This is about the SSD in a notebook. It appears the SSD is already going bad, possibly even corrupting data. It appears to return different data everytime it's accessed while not in use (see below for ...
1
vote
1answer
30 views

How to be sure that readonly snapshot is not corrupted in BTRFS?

How can we sure that a readonly snapshot is not corrupted due to a disk failure? Is the only way calculating the checksums one on another and store it for further examination, or does BTRFS handle ...
0
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0answers
38 views

CheckSum error, cannot boot

I was watching a video on my Acer Aspire laptop when I accidentally hit it on the left side of screen with my leg, the hit was very minor. But just after the hit the video stuck and started giving a ...
57
votes
17answers
15k views

Does an identical cryptographic hash or checksum for two files mean they are identical?

I have 2 excel documents and I want to check if they are exactly the same, apart from the file name. For example, the files are called fileone.xls and filetwo.xls. Apart from the file names, their ...
0
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2answers
53 views

Given an MD5 checksum and a random file. Is it feasible to add a suffix to match the checksum?

I often hear that MD5 is insecure. But I am not sure how it can be manipulated. I don't want to be the guy who just repeat "MD5 is insecure" without knowing some details. Say, I have an 128-bits MD5 ...
1
vote
1answer
265 views

Derive sha1 hash from openssl binary base64 value

Digital Cinema Packages contain checksums in the following format as described here: $ openssl sha1 -binary 'dcpfile.xml' |openssl base64 IxcfhXNHlw+1bbDFu0kp8KRylpU= How can I take a value such as ...
2
votes
1answer
352 views

How to get Btrfs verify checksum for one file?

Btrfs offers these commands to verify data integrity/checksums: btrfs scrub start <path>|<device> btrfs check --check-data-csum However, AFAIK those always verify whole filesystems; the ...
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1answer
75 views

What does star in .sha file mean?

The output contains one line per file of the form "{hash} SPACE ASTERISK [{directory} SLASH] {filename}". So what does * mean?
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3answers
5k views

How to generate MD5 hash value for multiple files in a folder using cmd

As mentioned in this page, the command:CertUtil -hashfile yourFileName MD5can be used to obtain the MD5 hash value for a particular file. How can I find the MD5 hash values for multiple files in a ...
1
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1answer
96 views

Windows 10 corrupts FAT partition checksum

I have a FAT16 partition (primary) that takes a total of 10.00MB of a standard USB drive. The rest of the space on the USB drive is unallocated so this is the only parttion I have there. When I plug ...
1
vote
1answer
84 views

File checksum value changed after a long time on unused drive

I have a drive with stored data that I haven't used for 3 years or more. I had then checksummed a lot of files with corz checksum. Now I'm backing up that old data into another drive, and to be safe ...
0
votes
1answer
101 views

mdadm wont mount due to checksum error

I have ubuntu raid5 on 4 disks of 1tb disks which had no dirty shutdown or power issue. The bootdisk is 5th disk which is not on mdadm. I also have XP on my bootdisk which I just started today. XP ...
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0answers
76 views

How does rclone perform remote checksum, and what is its effect on bandwidth?

I'm trying to store photos on amazon cloud drive using rclone, and whenever I upload a batch of photos, both my upload and download spikes as reported by my ISP. So if I upload 75 GB, my monthly ...
3
votes
1answer
175 views

What does shasum's --portable option do?

The shasum utility has a a -p/--portable option with the following description: -p, --portable read files in portable mode produces same digest on Windows/Unix/Mac I've never ...
12
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2answers
2k views

Why do I get different results from Mac's shasum than from other shasum calculators?

I'm entering: appletree:~ somename$ shasum -a 512 <<< test And the output is: ...
2
votes
0answers
434 views

netflix stall via linux iptables nat, tcp checksum errors (with workaround)

I've been trying to track down this problem for several days. I still haven't worked out what is going on, or how to fix it properly, but I do have a workaround. Problem summary Netflix stalls when ...
1
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1answer
350 views

Checksum for file rebuild

Is there a file checksum designed specifically for recovering a single file (archive) with data corruption? Something simple like a hash that can be used to recover the file I am trying to archive ...
0
votes
2answers
803 views

Windows Checksum Utility [closed]

I would like to install WinMD5Free.exe to run checksums - anyone know if it is legitimate? Many other sites offer it (CNet etc. so it seems ok). I have to check numerous downloads and want to verify ...
0
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2answers
1k views

How to checksum and verify all files on a filesystem

I would like to run sha1sum or md5sum on all my files recursively, store the results to a file (or a couple of files) and then be able to scan through the files again to verify the integrity of the ...
2
votes
1answer
237 views

Sha1Sum on kali.org

I am unable to download kali linux from their official website kali.org. I try to verify the sha1sum but all I get is invalid https://gyazo.com/2e02792c685fbd2ebfd50e04fe218501. Any ideas? I can ...
1
vote
4answers
662 views

How to verify checksum in a .mds file format?

I got the hadoop checksum file from https://dist.apache.org/repos/dist/release/hadoop/common/hadoop-2.7.1/hadoop-2.7.1.tar.gz.mds. But the file format is not the ones expected by tools like sha256sum. ...
3
votes
1answer
1k views

Can I calculate the checksum of a file as I create it?

I am creating a large tar archive and I would like to create the checksum of the archive too. I could achieve it like this: $ tar cfz archive.tar.gz files $ sha256sum archive.tar.gz > archive.tar....
2
votes
1answer
386 views

Which checksum-generating command line programs are native to macOS?

[Migrated question from stackoverflow here, because they said it was off-topic.] I'm looking for a list/an overview of the command-line programs native to macOS that let you calculate checksums. I ...
2
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0answers
715 views

Thinkpad T410 not booting: Simple solution?

I have a Lenovo Thinkpad T410 which I left outdoors overnight after a BBQ... No rain but likely some humidity. Symptoms? - Initially, screen remains black, nothing happens upon pressing power button....
3
votes
2answers
1k views

Sha256 checksum on terminal displaying strange characters

I've installed the hashalot first to use the sha256. Then something strange happened when using the command + filename: mlockall: Cannot allocate memory Warning: couldn't lock memory, are you root? ...
2
votes
4answers
7k views

how to verify whether a compressed .gz is corrupted or not?

I have many gz downloaded from the internet, and I would like to make sure they are not corrupted. Does the fact that I can open the archive with winzip on windows proves that everything is fine? I ...
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0answers
216 views

How to batch delete files based on their checksum matching an existing list of checksums

I'm looking for a means of deleting files based on their checksum matching a list of previously seen checksums in a text file or some other list. The context is a large photo organization project ...
0
votes
3answers
2k views

What is the exact meaning of the QuickSFV comments at the end of an SFV file?

What are the QuickSFV comments at the end of an SFV file based on? 25-Monty_Python-The_End-EOS.mp3 D387716E ;Q1-1c11727069c13b6 ;Q1-///4AA== In version 2 it had a line more: cowiso-xvid-yrrol....
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2answers
174 views

Find/check redundant files for cleanup and backup purposes

Very often I want to find out if the contents of given folders match or if the content of a single folder is redundant - maybe to check if it's duplicate and can be removed or to make sure there are ...
1
vote
2answers
1k views

calculate checksum of every file that is being written to HDD

Is it possible to automatically calculate checksum of every file that is being written to HDD? My OS is Linux. I've read that btrfs stores some kind of checksums for files. Would be possible to dump ...
0
votes
1answer
28 views

prevent file copying not via permissions

Is there any way I can prevent a file from being copied? I don't mean via the file system, but I mean by somthing that must change if the file was copied, like some sum or timestamp My goal is to ...
2
votes
1answer
425 views

Computing a checksum of a huge file (30 GB)

I have a huge data set consisting of several files, with size of some of the files exceeding 30 GB. After compressing, transferring the data set over the network, and decompressing again I am ...
0
votes
1answer
127 views

Shell script, AppleScript Mac OS X

I’m trying to copy embedded metadata from image files and write to a .txt file, as well as generate MD5 and SHA1 checksums for the same images to be added to the same .txt file. I can run this ...
1
vote
1answer
546 views

What defines a CMOS checksum in a BIOS system?

I am sure that many of you have seen and experienced the dreaded "CMOS checksum error" first hand. But what is it? CMOS Checksum error What is it a checksum of? The entire content of the CMOS data?...
2
votes
0answers
1k views

Unable to update Bios in Lenovo T61 due to damaged battery - What is the way to bypass this issue?

I would like to update bios on my T61 but unfortunately battery died back in the stone age. The whole notebook is a Dual core T7100 1.8 Ghz Centrino Duo without Nvidia graphic card (it has intel ...
8
votes
5answers
3k views

Do we really need to check the integrity of downloaded files? [duplicate]

I downloaded a huge amount of files, but discovered the use of md5 and sha as integrity checkers quite recently. From then I always prefer to check it for big downloaded files, even if I never found ...
0
votes
1answer
118 views

Excel Formula show with result as well as [closed]

I have a sheet with: A B C 7 5 =A1+B1 So, C1=12. Is it possible that D1 shows the numbers 5,7 used in the sum in C1?
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0answers
400 views

How do I check integrity of a file from DreamSpark?

I have a very unstable connection and it cut off multiple times while downloading Windows 8.1 using Microsoft's SDM, so I'm kind of concerned to how I can check to see if the file is still intact once ...
3
votes
1answer
926 views

Why do repeated downloads for Google Chrome setup have each time different hashes?

I've tried downloading the setup files for a standalone offline installation version several times in rapid succession. Each next file has an identical size but a different hash. Why is that? Do they ...
0
votes
2answers
112 views

File integrity checking

I have a lot of PDFs and many of them may be corrupt. Rather than checking each one, how could I check them all at once and delete any that are corrupt? Using Linux. I also don't have a way to get ...
0
votes
3answers
77 views

Extract identical files from two directories

I am looking for a linux solution for the following problem: Given two directories with a large number of files. All file names are random and different in both directories. The contents of some of ...
0
votes
1answer
2k views

Rename files by md5 checksum [closed]

What program can I use to rename files with their calculated md5 checksums? GUI or CLI Programs for Linux or Windows or scripts for DOS or the Linux terminal.
0
votes
1answer
3k views

Windows 8.1 Checksum

I've looked all over for the sha-1 or sha-256 checksum for the windows 8.1 iso that you get with the Microsoft’s “Upgrade Windows with only a product key” page but none of the check sums provided on ...
7
votes
1answer
5k views

How does one verify the PGP RSA and/or DSA checksum signatures for putty?

To verify the download integrity of putty, how is the best way to first verify the "SHA-512: (RSA sig) | (DSA sig)" PGP signature of these check-sum files for putty? (I am guessing "sig" means ...
11
votes
2answers
28k views

Microsoft Windows ISO checksums

Is there an official source for Windows ISO (XP+) checksums, online? Wanting to download some older Windows versions, for support purposes, but they don't appear to be available on Microsoft's ...
0
votes
1answer
1k views

Checksums don't match is that bad?

I recently started looking at VisualStudio 2012. I tried downloading it from the official Microsoft link but it failed with some errors. As of some suggestions I downloaded the DVD5 ISO image to ...
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2answers
689 views

Is it possible to recalculate the system configuration checksum on a Cisco RV180W

My Cisco RV180W has a corrupt configuration which is breaking the user interface in a few places. After a factory reset, it's fine - but if I restore my previous configuration it breaks again. The ...
21
votes
6answers
12k views

Does recompiling a program produce a bit-for-bit identical binary?

If I were to compile a program into a single binary, make a checksum, and then recompile it on the same machine with the same compiler and compiler settings and checksum the recompiled program, would ...
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votes
0answers
19 views

Video upload checksums not matching

We have a setup that takes a small quantity of small video uploads directly from people's mobile phones using apps, onto a small VPS. It rejects them if the MD5 checksum on the phone doesn't match the ...
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vote
3answers
2k views

How do I verify the authenticity of a linux system executable?

I'm aware of md5sum and gpg but I have no idea if there are recorded checksums for whatever current version of ubuntu is installed. Do these get recorded somewhere? Specifically I'm suspicious that ...