CheckSum Tool Manual

This is user manual for the CheckSum Tool. It is still work in progress, as is the tool itself.

The most important chapter is the Quick Start chapter which show how to get started with the CheckSum Tool. Other chapters have more in detail information about the tool.

The main window of the tool contains toolbar,list of filenames and checksums and statusbar. The toolbar has controls for most frequently used features, like creating and verifying checksums and changing checksum type. The file list contains filename (and some other attributes) and checksum for the file. The statusbar show some status information from the tool, like amount of files in the list.

The most frequently used features are explained shortly below:

To open a file containing checksums, select File | Open from main menu. Or click the Open button in the toolbar. In the dialog, browse for and select the file to open. The filename must contain or have an extension one of sfv, md5 or sha1. Otherwise CheckSum Tool does not recognize the file type.

If the tool can read the file, files in the checksum file are added into the list in the main window. Checksums are visible, but the tool does not automatically verify them.

When there is files with checksums in the main window, those checksums can be verified against checksums of actual files in disk. Select Checksums | Verify All from the main menu or click verify icon from the toolbar.

The tool compares checksums in the main window and checksums calculated from files in the disk. If the checksums are identical, OK text is added to Verified column in the main window. After all files are checked message is shown if all files were verified OK or not.

There are two ways to add new files to the list:

Single files can be added by selecting File | Add Files… from the main menu or from toolbar. This adds only the files selected in the dialog.

All files in the folder can be added by selecting File | Add Folder… from the main menu. This adds all files in the selected folder. If the selectec folder contains any subfolders, user is asked if files in those subfolders should be added also. Answering No tho the guestion adds only the selected folder. Answering Yes adds all files in all the subfolders too.

When the main window contains list of files which have checksums calculated, they can be saved to checksum file. Select File | Save or File | Save As… from the main menu. Select the filename and location for the file.

CheckSum Tool requires:

Download links for the .Net 2.0 framework:

The easiest way to install CheckSum Tool is to download and run the installer executable from http://checksumtool.sourceforge.net. The installer checks if the required .Net 2.0 runtime (or later) is installed. If the .Net framework cannot be found, the installer aborts.

Running the installer copies program- and documentation files to the system and adds the tool to Windows Start-menu.

The another way to install CheckSum Tool is to download binary archive file and extract files in it to some folder. All required files are in the archive file and CheckSum Tool can be run from the folder where the binary file was extracted.

Binary archive files can be downloaded from CheckSum Tool's downloads. Files are named CheckSumTool-version-bin.zip, for example CheckSumTool-0.2.0-bin.zip.

Checksums for files (or practically for any data) are numbers that are calculated from the given data using one-direction algorithm. One-direction algorithm means that one can calculate a checksum for the data. But the data cannot be determined from the checksum.

The algorithm is designed so that every possible data provides its own unique checksum. That means there should not be possibility for two files with the same checksum. With some older algorithms those duplicates are possible. With newest algorithms duplicates are not possible in practice.

Naming of the CheckSum Tool can be a bit misleading - strictly speaking MD_x_ and SHA-x are not checksums but cryptographic hashes. But generally speaking they can be called as checksums as they are used like traditional CRC checksums.

See Wikipedia articles for:

Wikipedia also has articles for most common checksum and hash functions. Please see those articles for more information.

The most common use for the checksums is to verify data integrity when storing and transferring it. If the checksums before and after the operation match, data has not been changed during the operation. For example FTP server can have checksum file next to files to download. Checksums for files in the server were calculated by the person putting files in the server. Now when somebody downloads the files and the checksum file, one can verify all files are correctly transferred (identical to files in the server) by calculating checksums for the downloaded files and comparing checksums to checksums in the checksum file.

How CheckSum Tool helps?

The main window is where almost all the work happens. As described in the Quick Start -chapter, it contains list of files for which to calculate and/or verify checksum.

The file list shows files processed and their related information, including the checksum. Visible columns and their data are:

The checksum is shown as a hexadecimal string. The length of the checksum depends on the checksum type.

First select the checksum type from the toolbar. Note that when checksum type is changed all checksums from the list are cleared.

Checksums for the files in the list are calculated by selecting the Calculate feature (from the toolbar or from the CheckSums menu). After the checksums for all files are calculated, they are added to the list. Length of the checksum varies by used algorithm.

Checksums in the list can be verified by selecting the Verify feature (from the toolbar or the menu). If one or more files do not have checksum in the list, those files are not verified (as there is nothing to verify).

When all files (that can be verified) are verified, verification status (Ok or FAIL is added to the list.

Existing checksum file can be loaded by selecting File | Open from main menu or clicking the Open button in the toolbar. In the dialog, browse for and select the checksum file to open. The filename must contain or have an extension one of sfv, md5 or sha1. Otherwise CheckSum Tool does not recognize the file type. (This will be improved in later versions.)

CheckSum Tool considers lines that begin with semicolon (;) in checksum file as comment lines and ignores them. E.g. line ; Created 1/4/2008 1:23:17 AM is ignored.

When one or more files have calculated checksums in the list, they can be saved to the checksum file. Only files that have checksum calculated are added to the file. Verification status is not added.

Files in the same folder than or in the subfolders of checksum file are stored with relative path. Files in other folders are stored with absolute path.

Select File | Save or File | Save As… from the main menu. Select the filename and location for the file in the dialog. It is recommeded to use file extensions that the dialog suggests:

Using these file extensions makes sure CheckSum tool (and many other tools) recognize the file type.

There are several ways to get answers to questions:

Two different discussion forums are available.

Support-list is one of the mailing lists.

Bug reports should be submitted to bug tracker.

Suggestions for new features should be submitted to Feature requests tracker.