DigiSign COM component Documentation

DIGISIGN COMPONENT v1.0

About DigiSign

DigiSign is a COM component that provides developers with a way to create data checksums, digital signatures, certificates, and a multitude of other applications that require some sort of one way encryption. DigiSign implements the MD5 message digest algorithm developed by Rivest in 1991 (rfc1321). For more information about the MD5 algorithm visit RSA Data Security's web site. The samples provided below will also give you a clear idea about some possible uses of DigiSign: password encryption, data checksums, protection against hacking and viral infections of executable files.

DigiSign can be used with any COM compliant environment: Scripting languages (VBScript, Javascropt), Visual Basic (Versions 4 and up), VBA (Word, Excel, Access ...), VC++, BC++, Delphi, Power Builder.

DigiSign Installation

Installation of the component is very simple using the provided installation utility. One file DigiSign.dll will be copied to the system directory (like \winnt\system32 for NT or \windows\system for Win95). However if you with to move the DLL to another directory remember to register the component using the resgsrv32 program before trying to use it.

Change to the directory where you copied the DLL and type:

regsvr32 cardcheck.dll

DigiSign Encryption Example

Using the component is as simple as

Creating the object

Calling the EncryptMD5 method

The following code demonstrates how to use DigiSign from VBScript / ASP. In this example we will create the "message digest" or "fingerprint" or "Signature" of a String or a File.

Dim S as String
Set MD = CreateObject("DigiSign.Signature")   'Create the Signature object
S = MD.EncryptMD5("This is our test string")       'Calculate and put the Signature of the passed String in String S
or
S = MD.GetMD5Signature("C:\Autoexec.bat")    'Calculate and put the Signature of the passed file in String S

Samples

Visual Basic: This sample demonstrates how to create checksums and digital signatures.

Download the Visual Basic Sample (size 3 KB)

Access: This sample demonstrates how to create bullet proof passwords for access databases.

Download the Access Sample (size 48 KB)

About Upgrades

Users can upgrade for free for minor version changes. For example, upgrades from version 1.00 to 1.99 are free. The upgrade from 1.99 to 2.0 may carry an additional license fee.

The latest version of the components are always available at http://www.donia.com/products.htm. If a fee is associated with obtaining the upgrade it will be noted on that page.

Upgrade Instructions

To upgrade the component from a previous version please follow these steps:

Stop all programs using the component. If you are using it in ASP stop IIS related services such as Gopher, FTP and W3SVC..

Install the update using the provided setup utility.

Don't forget to run regsvr32 as described above if you choose to move the DLL to another directory.

Restart the necessary programs / services.

Technical Support

If you require technical support please send complete details about the problem you are having to support@donia.com. Include the version of DigiSign you are using, any error messages, sample code snippets that demonstrate the problem (most problems are scripting errors), information about the hosting environment etc. For example, if you are using ASP to host the component please let me know what version of IIS and ASP you are running (and if you have installed any of the HotFixes). The more information you can provide in your request for help, the faster your problems can be resolved.

DigiSign Methods

Method Parameters Return Value Description

EncryptMD5 String
String to be signed or encrypted.

String (32 bytes)
MD5 Hash.
Use this method to get the MD5 Hash of a string. The length of the string is only limited by available memory.
Example:

DIM strOut$, strIn$
strOut = EncryptMD5(strIn)

GetMD5Signature FileName
String value of the File Name. UNC paths are supported.

String (32 bytes)
MD5 Hash.
Use this method to get the MD5 Hash / Checksum of a data file.
Example:

DIM FileName$, CheckSum$
CheckSum = GetMD5Signature(FileName)

About None Use this method to check if you are running an Evaluation version or a Full version.

Copyright © 1998 - 1999 Hassan Fekih. All Rights Reserved.

Method	Parameters	Return Value	Description
EncryptMD5	String String to be signed or encrypted.	String (32 bytes) MD5 Hash.	Use this method to get the MD5 Hash of a string. The length of the string is only limited by available memory. Example: DIM strOut$, strIn$ strOut = EncryptMD5(strIn)
GetMD5Signature	FileName String value of the File Name. UNC paths are supported.	String (32 bytes) MD5 Hash.	Use this method to get the MD5 Hash / Checksum of a data file. Example: DIM FileName$, CheckSum$ CheckSum = GetMD5Signature(FileName)
About	None		Use this method to check if you are running an Evaluation version or a Full version.