Program "Checksums v 1.0"
Contents
Function
Requirements
Usage
License
Author
Addendum
Function
The program "Checksums" is intended to ease the use of
checksum/key-files provided with "foreign" files, especially downloads
from internet locations, and to create such checksums files briefly. It
should increase safety for users and help webmasters. In detail
"Checksums" provides the following tasks:
1. Compute checksums/digital fingerprints of type Adler32, CRC32, MD5, SHA-1, SHA-256, SHA-384, SHA-512 of any file.
2. Save the computed checksums/digital fingerprints to file.
3. Scan checksum/key - files for the computed checksums/digital fingerprints.
4. Compute checksums/digital fingerprints for all files in any directory/folder and save them as checksum-files.
-Seven types of checksums are provided within one program.
-As a Java program, "Checksums" is platform-independent.
-All functionality provided via a "mouse-friendly" graphical user interface.
-A User-AND-Webmaster tool in one.
Requirements
"Checksums" is a stand-alone Java application, provided in an
executable jar-archive. For successful use it needs a Java Runtime
Environment (JRE) version 1.4 (or any higher version). Such is
available for free at http://www.java.com. A JavaSoftwareDevelopmentKit
(J2SDK 1.4 or any higher version) will do as well. Since "Checksums" is reading and writing
files the Java-security settings need to be adjusted for that purpose.
This can be done either by manually editing the ".java.policy" file
(usually located in the home-directory) or using the "policytool"
included with the JRE/JSDK. By default Java programs are not allowed to
read from or write to the local file system. The JRE/JSDK documentation as
well as several documents on the Java website explain details. For a
fast, "unsensitive" start, to allow Java applications (in contrast to Java-applets inside webpages - that is another topic) anything, the ".java.policy" file should look like:
grant codeBase "file://<ALL>" {
permission java.security.AllPermission;
};
Using these non-restrictive settings the permissions of the operating
system still apply! In case of problems reading and/or writing files
the reasons may be either the Java security settings or the
restrictions of the operating system like e.g. read-only directories,
etc.
Usage
To start "manually" enter "[path to Java-installation]java -jar
[path to]Checksummer.jar" from a console/DOS-window. It is also possible to
start without console. For Linux users the website http://public.contemporarycodes.de/LinuxOnGericom/index.html
contains a description how to set up an "consoleless" start, under
Windows open the Windows-Explorer, click "extras" in the menu bar,
select folder-options, therein select file-types, click "new", input
"jar", click "ok", select the "jar"-extension, click "extended", click
"new", input "open", then '[path to Java-installation]javaw.exe" -jar
"%1" %*' and close all open windows with "ok" or "close".
"Checksums" offers 5 buttons and 7 check-boxes for controlling program functions.
The check-boxes control which type of checksums will be computed.
Practical usage
1. For the "downloading user"
-download the required file(s) together with the provided checksum/key/fingerprint-file(s)
-Click "File to checksum" and select the downloaded file
-Click "Compute"
-Click "Scan (key-) file" and select the checksum/key/fingerprint-file
After that a mesage window will appear giving notice if any of the computed checksums is found in the checksum-file.
2. For the webmaster/publishing
-Select the type(s) of checksum to provide
-Click "Build folder checksums" and select either the folder or any
file inside the folder to compute checksum files for all the files
inside the selected folder.
Usage in detail
Button "File to checksum":
This button will open a file-selection window to choose a file whose
file-path will then appear right beside the button. It is also possible
to enter a file-path manually into the text-field. Any change of the
text-field will clear all computed checksums.
Button "Compute":
If the text-field contains an accessable file all selected checksums
will be computed. All computed checksums will be output to screen and
to the Java-console (or the console from which "Checksums" was started).
Button "Scan (key-) file":
The use of this button makes only sense if some or all checksums have
been computed. It is intended to check the checksum-files provided with
many downloadable files from internet (especially via FTP-downloads) to
contain the same checksum, sometimes called "key" or "digital
fingerprint" against the downloaded file. A file-selection window will
appear to choose a checksum-file, then the selected checksum-file will
be scanned to contain any of the previously computed checksums. The
result will be displayed in a separate window.
Button "Save checksums":
A file-selection window will open to choose or input a file. The previously computed checksums (contents of the light-green fields) will be written into that file.
Button "Build folder checksums":
A file-selection window will open to select a file or directory/folder.
If a file is choosen the containing directory will be used. For all
non-checksum-files in the choosen directory all selected types of
checksums will be computed. If all checksum-types are selected, then -for all non-checksum-files in the selected folder-
one single file containing all the checksums (named
<Filename>".CHECKSUMS.txt") will be written into that directory;
if at least one check-box is unchecked, then -for all non-checksum-files in the selected folder- for each selected
checksum-type a file named
<Filename>".CHECKSUM."<checksum-type>".txt" will be
written, containing just and only the checksum.
To quit the program use the window-frame buttons.
Please inform a.b.c@gmx.net about any possible malfunctions or missing functionality.
License
The program "Checksums" is free to copy and use for anybody.
There is no guarantee for correct functionality and any use is on full
responsibility of the user; the author takes no responsibility for any
possible damage in any way.
The copyright stays with the author Michael Besteck, Email: a.b.c@gmx.net.
Copying is only allowed unmodified including this README.html file.
Nobody may use "Checksums" to make profit in any way. Selling this program is prohibited, spreading it for free is requested.
Using the "Checksums" program more than once commits the user to send
an email to "a.b.c@gmx.net" using the subject "USING CHECKSUMS" (just click that email-address-link). (This
is for statistical purposes only.)
Author
Michael Besteck (Germany)
IT-system support specialist
Email: a.b.c@gmx.net
Addendum
You belong to the lucky ones in this world since you can read and own a computer.
This program is for free. Please donate the value of 1 single Euro to one of the following:
-Any organisation that helps helpless children
-Any organisation that helps the environment to stay natural
-Any organisation that engages against any kind of war
Thank you