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30
votes
8answers
7k views

Can a file be maliciously changed in a way that maintains its original SHA-1 Hash?

According to this article, and many others, SHA-1 is not secure. In my case, I am not concerned about passwords or digital certificates. I am concerned about file integrity. Is it reasonably ...
15
votes
1answer
237k views

How do I recover the password of a RAR file on Mac OS X?

I'm running Mac OS X 10.6.2 and have been handed a couple of old files that need to be extracted. Old backups or finances or bills I believe. They are RAR files, and password protected. Is there a way ...
14
votes
5answers
3k views

Why is MD5 still used heavily?

MD5 seems to have well documented vulnerabilities and yet it remains widespread in its usage. Does anyone have any reasons for it remaining a viable option when other alternatives (e.g. SHA-2) seem to ...
11
votes
3answers
2k views

md5: Why is my command-line hash different from online md5 hash results?

On Mac OSX Leopard PowerPC, if I do: echo "hello" | md5 on the command line, the result is: b1946ac92492d2347c6235b4d2611184But if I enter hello into one of the online md5 hash sites like ...
9
votes
1answer
765 views

Which file system automatically stores hashes of files?

Which file system automatically computes and stores hashes of files and later checks them at access to detect corruption?
8
votes
2answers
1k views

How can zero byte files generate a hash value?

How can a zero byte text file generate a hash when hashed with sha1sum, sha256sum etc? What data are the programs hashing to generate a hash value? Ta
8
votes
4answers
28k views

Is there an Excel function to create a hash value?

I'm working with a number of data lists that are keyed by document name. The document names, while very descriptive, are quite cumbersome if I need to view them on (up to 256 bytes is a lot of real ...
8
votes
2answers
657 views

MD5 and SHA1 checksum uses for downloading

I notice that when downloading a lot of open source tools (Eclipse, etc.) there are links for MD5 and SHA1 checksums, and didn't know what these were or what their purpose was. I know these are ...
5
votes
3answers
490 views

Why does sha1sum act differently with the same input?

I'm trying to replicate the behavior of the sha1sum executable in some java code, however, in the process I've discovered that sha1sum appears to behave differently given the same input in two ...
5
votes
3answers
1k views

Best Way to Archive Digital Photos and Avoid Duplicate File Names

This problem pertains to archiving of digital pictures taken from multiple cameras. Answers here covered the general topic of the-mechanics-of-backups: How do you archive digital photos and ...
5
votes
2answers
447 views

Calculating sha256sum of a dvd

I have a burnt dvd from an iso image. I have also sha256sum of the iso image. to compare hashes, I created an iso image from the dvd and executed sha256sum image.iso, but it differs from the hash of ...
5
votes
3answers
953 views

What is a tool for getting a complete directory/file listing with detailed information including hash(es)?

Once in a while, I take a complete snapshot of my drives with a command like the following. > for %i in (%drives_hd%) do @dir %i:\/s/a/o>>File_List.txt This gives detailed information ...
5
votes
1answer
3k views

enabling LM hash in Windows 7

Is there any way to enable/convert an NTLM hash for a user account on Windows 7 to a LM hash? I know it's not secure, but I am trying to test something. Is it even possible?
4
votes
4answers
5k views

OpenSSL hash function for generating AES key

What hash function does OpenSSL use to generate a key for AES-256? I can't find it anywhere in their documentation. $ touch file $ openssl aes-256-cbc -nosalt -P -in file enter aes-256-cbc ...
4
votes
1answer
3k views

“line length exception” in hashcat (kali linux)

I've received this line: root:$1$25A116L54$7/IbiL1ZsUyPwYBx/zuNv/ and asked to crack the password. So, I created a crack.hash file and put the following in it: $1$25A116L54$7/IbiL1ZsUyPwYBx/zuNv/ ...
4
votes
3answers
564 views

How secure is it to use a password hash of a common English word as a WPA2 key?

I have a wireless router, and I want a difficult password that is still, in a way, easy to remember. I came up with this idea to take the MD5, SHA-1, SHA-256, or whatever hash of a common English ...
4
votes
1answer
186 views

What files from the /boot partition, in addition to the MBR, must be hashed in order to detect an “evil maid” attack against LUKS-encrypted Linux?

Are boot.img, initrd, and vmlinuz adequate or should the entire contents be hashed? I am not familiar enough with the Linux boot process to answer this with confidence myself.
3
votes
3answers
4k views

sha1sum for a directory of directories

sha1sum ./path/to/directory/* | sha1sum the above was posted as a way to compute a sha1sum of a directory which contains files. This command fails if the directory includes more directories. Is ...
3
votes
1answer
912 views

How to check file against a hash on windows 7?

How to check downloaded file against its hash (SHA-256 Hash, SHA-1 Hash, MD5 Hash) on windows?
3
votes
1answer
111 views

Any examples of duplicate MD5 Hashes?

I was wondering, as it is theoretically possible to have duplicate MD5 hashes, are there any known examples of this, or is it all just theoretical?
3
votes
1answer
164 views

How to configure Firefox to warn or reject SHA-1 signed certificates?

Is there a way to configure Firefox either through an add-on, plugin, or other setting that will either reject or warn whenever it encounters a certificate that has been signed using SHA-1?
3
votes
1answer
3k views

What is the fastest MD5 sum calculator?

I tested the speed of md5sum on a few Ubuntu 8.04 servers Pentium III 700 MHz: 52 MB/s Atom 1.6 GHz, 32-bit: 119 MB/s Core 2 (Yorkfield) 2.5GHz, 32-bit: 194 MB/s Core 2 (Yorkfield) 2.5GHz, 64-bit: ...
2
votes
4answers
485 views

How do I verify a GPG symmetrically encrypted file?

I created an encrypted file with symmetric encryption. gpg -c 50GBfile Now I want to delete the original. Before I delete the original, I want to verify the integrity of the encrypted file. ...
2
votes
1answer
60 views

Inconsistencies on MD5 checksums

I am trying to obtain the md5 hash of a string. Said string consists of only uppercase and lowercase letters and digits. No other characters, including spaces and newlines. The string is inputted via ...
2
votes
1answer
633 views

Is the linux md5 password hashing considered secure?

On my RHEL6 linux is configured to use MD5 password hashing is the linux usage of MD5 for password hashing considered secure?
2
votes
1answer
31 views

How can hashes be used to efficiently keep track of version changes in documents?

I have heard that open source software uses these. Are they computed on an entire file? Like if you changed one letter of Moby Dick the hash would be different? I am curious about these for keeping ...
2
votes
1answer
3k views

Can Robocopy ensure file integrity?

I am trying to copy a large file, around 10G size, over Internet using Robocopy, but I am a bit concerned about the file integrity. So can I just trust Robocopy to ensure file integrity or I need to ...
2
votes
1answer
995 views

Compute salt with known plaintext and hash?

I have the string that was used in a webapp with md5 hashing to come up with a hash. I also have the hash. But the md5 of the string doesn't match the hash, so I'm guessing there's a salt involved. Is ...
2
votes
0answers
62 views

Embedding index in pdf files [closed]

Are there any (free) tools for building an index of a pdf and embedding it in the file in order to speed up searching? I know Acrobat Pro has a catalog option but I was hoping for a free tool and ...
2
votes
1answer
834 views

QR Codes for Files on Google Code

When you download files from Google Code now (example), in addition to the text version of the SHA1 hash, it includes a QR code of it. The device that the file was downloaded to is the one that has ...
1
vote
3answers
282 views

Current alternative to the old CHECKSUM program

I'm looking for an application that does md5/sha hash check on specific files/folders periodically and store an index file per folder for future verification. I remember such application exist in DOS ...
1
vote
2answers
406 views

Why is an internal table of PATH directories maintained?

I was looking for what rehash command does and found this: The rehash command re-computes the internal hash table of the contents of directories listed in the path environmental variable to ...
1
vote
1answer
270 views

/etc/shadow in old format, where is salt stored?

In /etc/shadow I have entries such as admin:YtChlvAGYzva2:16318:0:99999:7:::. I know the original password and would like to generate the same hash somehow. However, running openssl passwd -crypt ...
1
vote
2answers
3k views

Is there a way to detect encryption used on a file?

I have a small file that is encrypted and I want to see if it is a encryption method that has been broken or cracked.
1
vote
3answers
57 views

Should I use an SSD or HDD to hash lots of data?

Purely in terms of drive life which will be better for hashing hundreds of thousands of files - SSD or HDD? Background - My HDD has files which I want to hash and compare with data in a spreadsheet, ...
1
vote
1answer
49 views

How does applications read my hashed passwords?

mpdas (last.fm scrobbler for mpd) forces one to write password hashed in md5. But if it's hashed, how does it login to last.fm? Isn't hash function one-way only?
1
vote
1answer
177 views

Is it possible to write an app that ignores the zip archive password?

I am not sure how password protected archives work but is it the programs enforcing the protection or is it the way the format works where if it's password protected, there is no way to extract the ...
1
vote
2answers
9k views

Strongest Encryption and Hashing Algorithms Today [closed]

Basically, I want to know what the strongest (hardest to break) encryption algorithm today is. The same goes for the hashing algorithm. Let's say I pick a super-strong password too (bonus: how long ...
1
vote
2answers
442 views

is it possible to create custom columns (such as checksum/hash column) in windows explorer?

Is it possible to create my own custom column in Windows Explorer when listing files in "Details" mode? Right now, I have: Name Date Modified Type Size Hash I would like ...
1
vote
3answers
3k views

md5sum of files in two folders

I'm trying to compare all the files in two folders via an md5sum in one command. Some like the following (bash) in Debian: $ cd ~/FOLDER1 $ md5sum ~/FOLDER2/* | md5sum -c - The idea is that the ...
1
vote
3answers
3k views

How to add hash to MS Word documents?

I'd like to add a SHA, or some other kind of a hash to a Word (for Windows) document. Is there a good program / macro that would help me with that? Or some kind of a tutorial somewhere on the net? ...
1
vote
1answer
326 views

Where can I find hashes for Mozilla applications?

What is a reliable source for cryptographic hash values for Mozilla applications? Update 1: the value from http://releases.mozilla.org/pub/mozilla.org/thunderbird/releases/latest/MD5SUMS, ...
1
vote
2answers
56 views

Is encrypting the password legal? Not using any hash methods [closed]

I tried to login to my college social network site but I forgot my password so I clicked the "Forgot Password" link then an email has been sent. It stated in that email my username and the super duper ...
1
vote
3answers
181 views

How can SHA512 make a long string into a short string

I´m wondering how this random and very long string €£$€@]}$€{[$£}]£[€€£$€@]}$€{[$£}]£[€]}€486745896€$@fdhhsgpbkjhYUVYUDTYhµµµ½789ty45thhrhYUFVYU7645646f8cgI JKHVruxty dw78fg f 9w64f ...
1
vote
1answer
2k views

How to make sure a downloaded .iso matches a hash value?

I have download the .iso file as guided here and there is part that says to verify the downloaded .iso with CRC or SHA-1 hash value. Make sure that the CRC and SHA1 hash values of the downloaded ...
1
vote
2answers
632 views

Is there a way to search for files by hash value?

Is there a way I can have a hash value as input when searching for files and a complete list of files and their locations as output? This could be helpful when trying to pin point file duplicates. I ...
1
vote
2answers
651 views

Obtain SHA256 Value for Subject Key Identifier

Using Keytool we can view the details of a Keystore with the command keytool -list -v -keystore <KeystoreName> This returns a set of values including a Subject Key Identifer ...
1
vote
0answers
15 views

md5 hash a large file incrementally?

In the browser, I read in a file using the JS FileReader().readAsBinaryString(). Using the CryptoJS library I can MD5 hash the data. This works fine but I do not know how to handle large files. E.g. ...
1
vote
0answers
1k views

How to verify 7zip'd files integrity

For some files I have compressed, I have been looking for a MD5 add-on to 7zip (As I have the MD5's by way of an Explorer Column Handler, in xplorer2); or a CRC Explorer Column Handler (Because 7Zip ...
1
vote
1answer
36 views

Is it possible to store Hashed data in a different field than userPassword in LDAP

I've been asked to store hashed data in a LDAP server. Putting hashed passwords is easy but I'm not sure if LDAP allows to store data like email hashed or even encrypted. Creating a LDIF file with a ...