Tuesday, November 3, 2009

17.2 Advanced Networking Option












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17.2 Advanced Networking Option


Security — the
protection of data — is one of the primary concerns of any business. This
book focuses on how the standard features of Oracle can be used to control
access within the database and thus improve the security position of your
business.


But what happens outside of the database? Is the data safe on a network
(LAN), an intranet, a MAN, a WAN, or the World Wide Web? Probably not. In
the military security community, a popular and commonly told story
concerns the detection of keystrokes from teletypes. Many years ago, an
evaluation team went to a popular electronic parts store and, for only a
few dollars, bought a handful of electronics components. When properly
assembled, these components became a crude but effective receiver that
could be tuned to the frequency radiated by the teletype keyboard. This
was an excellent example of the interception of data as it was being
entered — even before it had a chance to be encrypted. The story ends with
the team visiting the "secure" facility with a full copy of the supposedly
classified message that had been transmitted only moments earlier.


17.2.1 About Sniffers and Snoopers


A similar
situation exists today. Data is not usually encrypted between the
workstation and the database. Almost everyone has now heard of the terms
sniffer and snooper. These terms pertain to hardware and software that can
be located close to, but not necessarily physically attached to, the
network. You could use sniffers or snoopers to intercept network packets.
With sniffer or snooper technology, an interloper can: intercept, read,
modify, or substitute data as it travels through the network. Most
dangerously, the interception of data can include usernames and
passwords.


17.2.2 How ANO Works


Oracle provides several products that help you protect the
confidentiality and integrity of your data. These products can also help
you authenticate users. The base product is called the Advanced Networking
Option (ANO); ANO is an option that must be purchased separately from the
default RDBMS software bundle.


ANO first appeared with Oracle7 and incorporated features of several
previous products, primarily:




  • Secure Network Services



  • SQL*Net/DECNet


Neither of these products is now available.


ANO is used in conjunction with SQL*Net for Oracle7 or Net8 for
Oracle8, and provides all the functionality of those products in addition
to data encryption. Several encryption algorithm
options are currently supported (some of these are described in greater
detail in Chapter
15):



RC4 40

A 40-bit encryption algorithm from RSA Data Security, Inc.


RC4 56

A 56-bit encryption algorithm from RSA Data Security, Inc.


RC4 128

A 128-bit encryption algorithm from RSA Data Security, Inc.


DES 40

A 40-bit encryption algorithm based on the Data Encryption Standard,
which uses a security key that is randomly generated for each
session


DES 56

A 56-bit encryption algorithm based on the Data Encryption Standard,
which uses a security key that is randomly generated for each
session


Over time, these options will probably change. The number that follows
the encryption type indicates how many bits the algorithm will support.
Smaller numbers — like 40-bit encryption — will pose less of a challenge
for an eavesdropper to break to enable him or her to see the information
being transported. Although the ANO is available in other countries,
slightly different encryption capabilities are delivered outside the
United States due to U.S. Government export restrictions on strong
cryptography.


For single
sign-on support, you can use a third-party single sign-on server such as
Kerberos or SESAME, or you can use the Oracle Security Server (described
in Chapter
15), which is included with the default Oracle8 bundle. ANO works with
both standard Oracle and Trusted Oracle.


When considering the use of any encryption methodology, keep in mind
that encryption is another process that has to be completed in the
communications process. Each packet you send must be encrypted by your
software, and each packet received must be decrypted — both from the
client side and the server side. As a result, there will almost always be
some performance degradation. You can expect a potential range of
performance degradation of between 5 and 20 percent depending on the
complexity of the operations you are performing.











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