1.0 Overview
2. Security
Concepts
2.1
Hard
Document Privileges
2.2
Security
Tokens
2.3
User
Assignments
2.4
File
Encryption
3. Using
Security
3.1 Log In
3.2 Token Administration
3.3 User Administration
3.4 Assigning Owners
and Tokens to Objects
Intended
Audience
This document is intended
for use by licensed customers of Alpha Software Express' ExpressDesigner.
It contains information required for creating and using secured drawings.
To implement drawing security, users need either the Professional Edition
or the Enterprise Edition of the product. This document also assumes the
reader is familiar with the general concepts of Express Designer and has
read the Basic User's Guide.
© 2002, 2003
Alpha Software Express, LLC - San Rafael, CA USA
Send any questions or comments
to: aex@alphase.com
ExpressDesigner refers to this product1.0 Overview
BDI refers to the Basic Designer Interface
CDI refers to the Complex Designer Interface
Text in This Type refers to on screen buttons
Text in This Type refers to top level menu items
Text in This Type refers to specific menu selections, or input field labels
Text in This Type refers to file names
Level 0 security implements the concept of Hard Document Privileges. This allows any user to restrict certain actions on an otherwise unsecured drawing. It is included in all editions of the product, but is really only provides the suggestion of security. Hard Document Privileges are really designed to be used in conjunction with the other protection schemes implemented in the Level 1 and 2 security models.
Level 1 security builds on the Level 0 model by implementing three new concepts: drawing file encryption, user restriction and privilege token assignments. Together, they insure that only certain users can perform certain functions. Unauthorized users have no access to even reveal the document's contents. All Level 1 security mechanisms are totally self contained in each drawing file and there is no such knowledge shared between other Level 1 secured documents.
Level 2 security builds on the Level 1 model by introducing the concept of a security domain. This model removes the security mechanisms from the individual drawings and centralizes them under a Domain Administrator's care. Users and privilege tokens are assigned and maintained by the administrator and shared by all documents throughout the administrator's domain. In addition the concept of vault control is introduced, where the vault is defined by the Domain Administrator and refers to the directories that contain the secured documents.
This document focuses on
the concepts introduced in Level 1 under the Professional Edition of the
product. For more information on Domain Administration, see Enterprise
Administration.
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2.2 Security
Tokens
A security token is a virtual object
consisting on a name and set of privileges. It is the basic mechanism for
implementing the Level 1 and Level 2 security models.
Its name is important because it is the object's only identifier. Therefore, no token can have the same name as another within its domain. In the Level 1 model this domain is defined as the document being secured. In the Level 2 model, the domain is defined by the administrator.
The set of privileges which may be defined for a given token is the same set of privileges that comprise the HDP (see Table 2-1). Any combination of settings is valid, even if the same set was already defined under another name. Up to 32 tokens can be defined for each unique domain.
Once defined any combination of these
tokens can be assigned to any, or all, of the objects in a drawing. Any
combination of these tokens can also be assigned to any defined user. Then,
when ExpressDesigner
tries to determine which
actions are valid on which objects for a given user, it matches the token
names assigned to the object with the token names assigned to the user.
The privileges of the matching token names are then evaluated and combined
with the Hard Document Privileges. The final result defines the actions
allowed on an object. This model closely follows the Access Control List
security model used throughout the information industry. Objects that have
no matching tokens are completely inaccessible, unless the object is owned
by the current user (see next section).
2.3 User
Assignments
When using the BDI or CDI,
all drawing functions are considered to be unsecured, until the user logs
in. At that time the user can specify the security model to be used. Remember,
only the Enterprise Edition of ExpressDesigner
provides for both
models. A user name can contain any alpha-numeric character and is case
sensitive. The same applies to the password.
In the L1 security model, users and their passwords are established by the document's owner. In the L2 security model, users and their passwords are established by the Domain Administrator. In either model the user who first creates a drawing is always the owner of that drawing. Every drawing that implements either security model has an owner.
Likewise, the user who first creates an object is the owner of the object, so every object in a secured drawing has an owner.
Depending on the model and options set, these ownerships can alter the privileges granted by the matching tokens.
In the L1 model, the document owner is also the administrator and has all privileges granted for every object by default. Likewise, other users authorized to create objects within an L1 document are granted all privileges to the objects they own, regardless of the token assignment.
In the L2 model, the Domain Administrator has the option to decide whether or not document owners have all privileges granted to them for documents they own. In the same way, owners of objects may, or may not, have all privileges granted to them, depending on the choices made by the Domain Administrator.
2.4 File
Encryption
To prevent information from being
read outside of ExpressDesigner
and to insure only valid
users are granted privileges, L1 and L2 level documents are encrypted with
a proprietary algorithm, based on the document owner's name. When L1 or
L2 security is in force, all of the file types created by ExpressDesigner
are encrypted in this
way, except those GIF, JPG and BMP created by the Export
function.
3. Using
Security
Implementing secure drawings
is the same for the BDI or CDI, so the following applies
to both interfaces.
3.1 Log
In
To create or update any
secured document, you must first log in. From the Security
menu, select Login... and select the Security
Level. At this point the Username, Password
fields will be enabled for input. The Admin File
will also be enabled if you selected the L2 security level. Enter your
user name and password. Remember both are case sensitive.
If you selected Level 1 and are creating a new drawing you can makeup any user name and password, then click OK. If you already have unsecured objects drawn, you will see the following type of warning. If you select Yes, you will become the owner of all the existing objects and each will be assigned the token AutoAssign, which is created with all privileges enabled.
If you selected Level 1 and will be editing an existing drawing that is owned by someone else, you must enter the user name and password assigned to you by the owner, then click OK.
If you selected Level 2 you must also identify the Administration file you are logging into. Then enter the user name and password assigned to you by the administrator and click OK.
3.2 Token
Administration
Although you can add, delete
and modify tokens and users at any time, you should start a new secured
drawing by defining a logical set of tokens first. To begin token assignment
select User/Token Admin... from the Security
menu. The User Administration window will appear (figure
3-4). From that window's Security
menu, select
Token Administration. You will
then see the Token Administration window (figure 3-3).
The token number assigned in the upper right hand corner is for ease of
reference within the set of tokens defined and has no other intrinsic meaning.
To create a new token, just enter a unique name and set the privileges you want this name to carry. Then click on the Add button. The token will be added and the token number will be incremented to the next number. Enter the next token in the same way and so on, until your done. When your done, click the OK button to accept the changes, or Cancel, to ignore them.
To return to an added token, click Previous. You can also traverse through the list of tokens by pressing Previous and Next. If you want to update an existing token, just traverse to the subject token, make your changes and click Add again. If you want to delete a token, just traverse to the subject token and click Delete.
When you return to the main
window, the list of tokens you assigned will show up under the Security
menu (see figure 3-5).
3.3 User
Administration
Once you have a viable list
of security tokens defined, you can define your users. If you just defined
your list of tokens, your Administration window will still be visible.
Otherwise, enable it from the Security
menu, by selecting User/Token Admin... .
Your list of token names
will be visible as check boxes under the title, "Security Tokens Assigned".
Remember there can be up to 32 of them. Unassigned token check boxes will
be disabled.
To add a user, enter a unique user name and any password, then select the tokens to be assigned to that user. When you press the Add button the user will be added and the user number at the bottom of the window will be incremented to the next number. To return to the added user, click Previous. You can traverse through the list of users by pressing Previous and Next. If you have a large number of users defined, you can jump to a specific user by entering the user name and clicking the Find button. To modify an existing user, just traverse to the user in question, make the changes and click Update. If you want to delete a user, traverse to the subject user and click Delete.
When your done, select the close from the Options menu.
3.4 Assigning
Owners and Tokens to Objects
Once your drawing has been
secured by logging in, all new objects will be created with you as the
owner. They will also automatically be assigned the tokens selected from
the bottom of the Security menu. All
the tokens will be available to you for selection even if you're a user
that has not been assigned those tokens. You can change these at your leisure.
The selected items will remain in effect until you change them again or
exit the drawing.
Once these tokens have been assigned to an object they can still be changed, if the user has ReOwn as one of the privileges available to him/her. To do that, select the object of interest then select Tokens... from the Edit menu. You will see the Modify Object Tokens window (figure 3-6). Just make the appropriate selections and click OK, or Cancel.
Like tokens, the owner of an object can also be changed, if the user has ReOwn as one of the privileges available to him/her. To do that, select the object of interest then select Tokens... from the Edit menu. You will see the Modify Object Owner window (figure 3-7). Just select the new owner from the pull down list then click OK, or Cancel.
In the L1 security model,
both the object owner and the object's tokens can also be changed by the
owner
of the document.
© 2002, 2003 Alpha Software
Express, LLC.
All rights reserved.