MD5 Checksums are used to check the integrity of files. They are normally a 32 hexadecimal number (128-bit hash value) created by a cryptographic has function.
In short, a MD5 Checksum is useful for identifying a corrupt, incorrect or missing file.
Using fsum to create and verify a MD5 Checksum
fsum.exe is a command line application and therefore ideally used with batch files.
Creating a MD5 Checksum with fsum.
>fsum -d”d:\verification” -jnc -jm -r *.* >”d:\verification\CHECKSUM.md5″
Image 1 - The Checksum.md5 content (opened in Notepad)
I have changed two files to show the status of warning and errors. The document “Verification Testing.doc” has been deleted and the file content of “ReadMe.txt” has been changed.
Verify a MD5 Checksum with fsum.
>fsum -d”d:\verification” -c CHECKSUM.md5
fsum identifies a warning and an error.
Image 2 - fsum output
Options used:
-d <directory>, set working directory
-jnc, suppress comments
-jm, use MD5 format
-r, recurse subdirectories
-c, check sum against given list
Using Fsum Frontend to verify a MD5 Checksum.
Fsum Frontend also identifies a warning and an error.
Image 4 - The Fsum Frontend interface
Fsum Frontend can calculate 4 different checksums (SFV, MD5, SHA1 and SHA2), and it also allows 96 different hashes for files and text strings.
Using Md5Checker to verify a MD5 Checksum.
Md5Checker is my preferred MD5 Checksum interface, however Fsum Frontend has been included as it has a large set of supported checksums and hashes.
Md5Checker also identifies a warning and an error.
Image 3 - The Md5Checker interface
Md5Checker can calculate a MD5 checksum and a MD5 hash for a text string.
My Options for Md5Checker
Menu Tools > Options or the Options button on the main window.
- On Add tab, set include for Add folders to “*”. This ensures all files are included in checksum.
- On Save tab, ensure Always save full path is unchecked. This ensures the checksum path names are relative to the top folder.
- On Advanced tab, check Store last folder used. This allows the last folder location to be used for Add/Open.
Cool Features
- Fsum, Fsum Frontend and Md5Checker are all portable applications.
- Md5Checker allows association with the MD5 extenion, having a shell content menu and being able to include in the Send To menu.
- Md5Checker has real-time summary results icons information; as it progresses the checksum for each file the information is updated, Image 5.
- The item list can be filtered via the menu View or by clicking on the summary results icons, Image 5.
Image 5 - Summary results icons
Wanted Features
- Md5Checker does not have a Copy Path button on the main windows, only available via the menu Edit > Copy Paths.
- Md5Checker does not have a Copy All feature, to copy data from all columns.
fsum:
Homepage & Download: SlavaSoft Download: From Softpedia
Fsum Frontend:
Homepage & Download: Fsum Frontend Download: From Softpedia
Md5Checker:
Homepage & Download: Md5Checker Download: From Softpedia
Solution
This solution allows Md5 Checksums to be created for a set of files and then verify at a later date to ensure file integrity.
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