Re: Hiding PL/SQL Source code

From: Paul Quenneville <paulq_at_rogers.com>
Date: Mon, 04 Mar 2002 16:40:53 GMT
Message-ID: <psNg8.55$aFN.1@news1.bloor.is>

Wrap Utility
This appendix shows you how to run the Wrap Utility, a stand-alone programming utility that encrypts PL/SQL source code. You can use the Wrap Utility to deliver PL/SQL applications without exposing your source code.

Major Topics
  Advantages of Wrapping
  Running the Wrap Utility
  Guidelines
Advantages of Wrapping
By hiding application internals, the Wrap Utility prevents

a.. misuse of your application by other developers

b.. exposure of your algorithms to business competitors

Wrapped code is as portable as source code. The PL/SQL compiler recognizes and loads wrapped compilation units automatically. Other advantages include

a.. platform independence--you need not deliver multiple versions of the same compilation unit

b.. dynamic loading--users need not shut down and re-link to add a new feature

c.. dynamic binding--external references are resolved at load time

d.. strict dependency checking--invalidated program units are recompiled automatically

e.. normal importing and exporting--the Import/Export utility accepts wrapped files

Running the Wrap Utility
To run the Wrap Utility, enter the wrap command at your operating system prompt using the following syntax:

wrap iname=input_file [oname=output_file]

Leave no space around the equal signs because spaces delimit individual arguments.

The wrap command requires only one argument, which is

iname=input_file

where input_file is the name of the Wrap Utility input file. You need not specify the file extension because it defaults to sql. For example, the following commands are equivalent:

wrap iname=/mydir/myfile
wrap iname=/mydir/myfile.sql

However, you can specify a different file extension as the following example shows:

wrap iname=/mydir/myfile.src

Optionally, the wrap command takes a second argument, which is

oname=output_file

where output_file is the name of the Wrap Utility output file. You need not specify the output file because its name defaults to that of the input file and its extension defaults to plb (PL/SQL binary). For example, the following commands are equivalent:

wrap iname=/mydir/myfile
wrap iname=/mydir/myfile.sql oname=/mydir/myfile.plb

However, you can use the option oname to specify a different file name and extension, as the following example shows:

wrap iname=/mydir/myfile oname=/yourdir/yourfile.obj Input and Output Files
The input file can contain any combination of SQL statements. However, the Wrap Utility encrypts only the following CREATE statements, which define subprograms, packages, or object types:

CREATE [OR REPLACE] FUNCTION function_name
CREATE [OR REPLACE] PROCEDURE procedure_name
CREATE [OR REPLACE] PACKAGE package_name
CREATE [OR REPLACE] PACKAGE BODY package_name
CREATE [OR REPLACE] TYPE type_name ... OBJECT
CREATE [OR REPLACE] TYPE BODY type_name

All other SQL statements are passed intact to the output file. Comment lines are deleted unless they appear inside a subprogram, package, or object type.

When encrypted, a subprogram, package, or object type has the form

<header> wrapped <body>

where header begins with the reserved word CREATE and ends with the name of the subprogram, package, or object type, and body is an intermediate form of object code. The word wrapped tells the PL/SQL compiler that the subprogram, package, or object type was encrypted by the Wrap Utility.

The header can contain comments. For example, the Wrap Utility converts

CREATE PACKAGE
-- Author: J. Hollings
-- Date: 10/15/99
banking AS

minimum_balance CONSTANT REAL := 25.00; insufficient_funds EXCEPTION;
END banking;

into

CREATE PACKAGE
-- Author: J. Hollings
-- Date: 10/15/99
banking wrapped
0
abcd ...

Generally, the output file is much larger than the input file.

Error Handling
If your input file contains syntax errors, the Wrap Utility detects and reports them. However, the Wrap Utility cannot detect semantic errors because it does not resolve external references. For example, it does not report the following error (table or view does not exist):

CREATE PROCEDURE raise_salary (emp_id INTEGER, amount NUMBER) AS BEGIN
UPDATE amp -- should be emp

SET sal = sal + amount WHERE empno = emp_id; END; The PL/SQL compiler resolves external references. So, semantic errors are reported when the Wrap Utility output file (.plb file) is compiled.

Version Compatibility
The Wrap Utility is upward-compatible with Oracle. So, for example, you can load files processed by the V8.1.5 Wrap Utility into a V8.1.6 Oracle database. However, the Wrap Utility is not downward-compatible with Oracle. So, for example, you cannot load files processed by the V8.1.6 Wrap Utility into a V8.1.5 Oracle database.

Guidelines
When wrapping a package or object type, wrap only the body, not the spec. That way, other developers see the information they need to use the package or type, but they do not see its implementation.

Like all encrypted files, wrapped files cannot be edited. To revise a wrapped file, you must revise and re-wrap the underlying source code. So, do not wrap a subprogram, package, or object type until it is ready for shipment to end-users.

"ales voderka" <ales.voderka_at_e-bs.cz> wrote in message news:a5vovq$f8f$1_at_news.eunet.cz...
> Hello,
> I would like to know if there is any way how to hide PL/SQL Source code
from
> being available in database. The problem is that we have an application
> which is written in PL/SQL packages. Now we will have to install by our
> customers which will have administration access to the database. We would
> like to have our app in the database but we don't want to let them see our
> code. We use oracle 8.1.7.
>
> Thanks in advance
> Ales Voderka
>
>
Received on Mon Mar 04 2002 - 10:40:53 CST