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This library will carry the management of an
users database for login verification, and all the normal operations that you will need.
All the information is stored in an encrypted file.
I'm sorry that there are a couple of members
in the library whose names are in Spanish. Well, I'm Spanish and I cannot avoid writing
things in Spanish while I'm programing, although I try to make everything in the libraries
that I'm planing to export in English. For your information, Nombre means Name, and
Apellidos means Last Name (or Surname). If you find anything else in Spanish, tell me.
To use the library, among other things you
will have to provide a password to encrypt all the information that is stored there. DON'T
LOOSE THAT PASSWORD. This library doesn't have a master password or anything, so if you
cannot access the information stored in the file, me neither.
If you have any questions, doubts, comments
or bugs, please contact me.
History:
Added the 'ChangeRights' function.
Corrected a couple of minor bugs.
Added the possibility of opening the
database even when it is damaged (a wrong password is being used or someone has being
modifying the database externally).
Added the 'DamagedDB' property.
Version 1.02 26.03.98: Now the encryption
support is compiled into the library. The AREncrypt.dll file is not in the ZIP anymore.
Also the DEP file has changed to reflect this. Improved performance.
Version 1.10: Added properties to force
the use of strong passwords (MinPasswordLength, MustHaveAlpha, MustHaveNumbers,
MustHaveOnlyNumbers and MustHaveBothCases); added the ForceChangePassword method, so an
administrator can change the password for an user without needing the old password.
Version 1.20 14.07.98: Removed the
protection system to the library. From now on the code is not necessary anymore, and the
library is freeware.
INSTALLATION
In the ZIP file you will find the following
files:
ARUsersDB.dll
ARUsersDB.txt
ARUsersDB.DEP
Put all those files together wherever you
want. The .DEP file has the dependency information, that you will need if you want to
create the installation of a program that uses my library.
ARRandomPwdGen.exe is a program that will
generate random passwords of any length. You can use it to generate random passwords for
the library. Of course, it also needs the Visual Basic 5 SP3 run-time libraries.
PROPERTIES AND
METHODS
Properties:
Code. The code was necessary for the
library to work before version 1.20. It's still there for compatibility reasons.
DamagedDB. This property will be true if a
wrong password is being used to open the database, or someone has being modifying the
database file externally. The database has checksums that are encrypted as well, so the
program can control the state of the file. In version 1.0, the library wouldn't let you
open a damaged file, but this behavior is not correct when we are talking about critical
information, so I have changed it and added this property for you to check it after
opening the database with the 'File' property, and know if everything is right.
DatabaseOpen. If true, that means that the
library is ready to start working with the database.
File. Full path of the file where you want
to store the information. If the path provided doesn't exist, the library will create it.
LastError. If in any operation an error
happens, here the library will store a description of the error.
ListUsers (key). Key is a number or an ID
for the user. The property will return a class with the following members: Admin (true or
false, indicates if this user has administrator rights), Apellidos (String, last name),
Level (1 to 4, indicates the level of rights that this user has), Nombre (String, first
name) and UserID (String, ID of the user).
MinPasswordLength. You can set here the
minimum length that a password must have to be valid. Default is 0, although anyways the
library will not accept empty strings as passwords.
MustHaveAlpha. When set to True, to be
valid a password will have to have characters from a to z or from A to Z (at least one).
MustHaveBothCases. When set to True,
passwords will have to be composed by some character from a to z and some character from
A-Z to be valid.
MustHaveNumbers. When set to True, a
passwords will have to contain numbers to be valid (at lease one).
MustHaveOnlyNumbers. When set to true,
password will have to be composed only by numbers to be valid.
Password. You will have to provide a
password for the database to be encrypted with. I recommend that the password is between
25 and 40 characters long. You have to provide the password before setting the 'File'
property.
UnLocked. True or false, depending on if
you have introduced the right code to unlock the library or not. Since version 1.20,
always True.
UsersCount. Will return a long integer,
with the number of users that the database contains.
Methods:
AddUser (UserID As String, Password As
String, Level As Rights, [Name As String], [LastName As String], [Admin As Boolean =
Falso]) As Boolean.
UserID as string. The ID that the user
will have in the system. It must be unique, so two users cannot have the same ID. The
maximum length is 15 characters.
Password. The password that the user will
have. The maximum length is 15 characters.
Level. 1 to 4, indicating the level of
rights that the user has.
Name (optional). User's first name. The
maximum length is 15 characters.
LastName (optional). User's last name. The
maximum length is 35 characters.
Admin (optional). True or false, depending
on if this user has Administrator rights or not. Default is false.
This function will return True if successful
or false if it fails for some reason. Look at the 'LastError' property to get a
description of the error.
ChangeRights (UserID As String, Right As
Rights, [Admin As Boolean = Falso]) As Boolean. Use this property to change the rights of
an existing user. It will return 'True' if succesful or 'False' if the function fails.
ChangePassword (UserID As String,
OldPassword As String, NewPassword As String) As Boolean. Using this function you will be
able to change the password for an user. You will have to provide the user's ID, the old
password and the new one that the user wants to have. This function will return True if
successful or false if it fails for some reason. Look at the 'LastError' property to get a
description of the error.
DeleteUser (UserID As String) As Boolean.
Deletes an user from the database. True if successful or False if it fails. You just have
to provide the UserID.
ForceChangePassword (UserID As String,
NewPassword As String) As Boolean. Administrators can use this function to force the
change of a password for an user without needing the old password. Use this if someone has
forgotten the password, instead of having to erase and add the user again.
VrfyUser (UserID As String, Password As
String) As Boolean. When the user is trying to logon, you just have to use this function
to quickly verify the identification that the user is providing. The function will return
True if the identification is correct or False if it is not.
EXAMPLES
This is an example on how to use the library:
- To start working with it and open the database:
Dim UsDB As New ARUsersDB
UsDB.Password = Password
UsDB.File = App.Path & "\Users.dat"
If UsDB.LastError <> "" Then
MsgBox UsDB.LastError
End If
Dim bRes As Boolean
bRes = UsDB.AddUser(UserID, UserPassword, Level1, "Alvaro", "Redondo",
True)
If Not bRes Then MsgBox "There has been an error when trying to add this user to the
database: " & UsDB.LastError
Dim bRes As Boolean
bRes = UsDB.DeleteUser(UserID)
If Not bRes Then MsgBox "There has been an error when trying to delete this user from
the database: " & UsDB.LastError
- To verify the identification that an user is providing to
have access to the program:
Dim bRes As Boolean
bRes = UsDB.VrfyUser(UserID, Password)
If Not bRes Then
MsgBox "The identification is incorrect."
Else
MsgBox "Access granted."
End If
- To check some information about an user:
Print UsDB.ListUsers (UserID).Nombre
TIP: If you want to add an user with an
empty password, so the user will have to add his / her password in the next logon, use
some string and identify it as an empty string. For example, the empty string could be
something like: "emptyemptyempty". When you add an user without a password, put
that string as the password. Whenever an user introduces his / her identification without
password, verify the account using that string. Also, make sure you don't allow that
string to be used as a normal password. The library will not accept blank passwords for
security reasons.
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AR Users Database
ActiveX Library 1.20