DataSnap Filters Compendium Updated to Delphi 10 Seattle

Very quick info.

Not tremendous useful today as when developed (Delphi 2010 time frame) but, if someone is still using my DataSnap Filters Compendium (and I know some users heavily use it), now can find the Delphi 10 Seattle version on github. Currently works all the speed test and the server/client test. Consider this as a very stable beta.

Here’s the project repository

New beta version for DataSnap Filters Compendium

I’ve been very busy lately with some Delphi related events here in Italy

so I havent too much time for my personal open source project. But now I’ve released new beta version for DSFC.

This release address a problem with the cypher filters.

Cypher filters arent completely compatible with the previuous version, so you need to rebuild the server and the client if you want to use this new version of DSFC.

There are one known issue:

  • Cannot have multiple connections in a client with the same filters but different cipher keys connecting to different servers.

Some users asked to me a little tutorial to setup a demo application with the cypher filters. Now there is a project group illustrating how do it.

There is also a new net speed test.

I’m waiting for some testers feedback comment before of 1.1 version.

As usual you can find the source code in the GoogleCode SVN repository

Happy testing!

News and small fixes for DataSnap Filters compendium

DataSnap Filters Compendium has been used by many users so far. I’m planning to do some change in hash filters (that do not will affect already written code) but until new version will ready I have 3 nice news about DSFC:

1. Now the project is on Google Code.

2. Franco Perana, the first contributor to the project, has fixed and optimized the LZO filter.

3. Have you used DSFC and do you want to see your application listed in the “Application Using DSFC”? If yes, leave a comment on this post with some details of your application amd I’ll add it in the proper list.

DataSnap Filters Compendium

What’s DataSnap Filters Compendium

DataSnap Filters Compendium (DSFC) is a compendium of 9 filters for DataSnap 2010.
The filters are divided into 3 groups:




HASH filters
The HASH filters helps avoid to any spiteful person to modify datasnap message through an “Man in the middle” attack (
Functioning is basing on an easy principle. After sending the message, the filter calculates the hash of the message and tags along it to the message. When the message gets to destination, the filter recovers the hash calculated by the client and recalculates it on the remaining part of the message.
If the part of the extrated hash (calculated at the beginning) and the hash recalculated to the end are equal, the message hasn’t change.
To avoid someone could modify the message and also recalculates the hash, after calculating the hash, a GUID is tagged along to the message, which just the sender and the receiver know.
This kind of filters DOES NOT AVOID THE UNAVOIDED READING OF DATA,it avoids just the modification.

CIPHER filters
The CIPHER filters are the most interesting filters. Many datasnap users have requested a built-in system to get the data transmission safe. This set of filters colud be the answer.
In the actual version I’ve implemented Symmetric-key algorithms. Maybe I’m going to develop of Asymmetric-key algorithms filters.
Implemented algorithms features are well known, I list them as follows just to be completed:

Blowfish has a 64-bit block size and a variable key length from 32 up to 448 bits.
The filter version has a keysize = 56 byte.

AES Round 2.
AES has a fixed block size of 128 bits and a key size of 128, 192, or 256 bits, whereas Rijndael can be specified with block and key sizes in any multiple of 32 bits, with a minimum of 128 bits and a maximum of 256 bits.
The filter version has a keysize = 32 byte.

Triple DES with 24 byte Blocksize, 24 byte Keysize 168 bits relevant
The filter version has a keysize = 24 byte.

Triple DES with 8 byte Blocksize, 24 byte Keysize 168 bits relevant
The filter version has a keysize = 24 byte.

COMPRESS filters
Actually the LZO compression is the only one that exists, and is one of the faster compression algorithms.
The compression ratio compared to the ZLib is worse but about 3 times faster (as the table in next paragraph shows).

DSFC has a huge suite of unit tests and speed tests.
The speed tests show how filters are fast and how the data stream size is affected by their work. Follow table contains results of speed test execution (DSFCSpeedTest) on my workstation. If you want give a meaning to those numbers, see the code of the speed test 🙂

== HASH FILTERS == 1000 iterations
MD5             =  161ms (stream size:  8304 byte, filtered stream size:  4184 byte)
MD4             =   99ms (stream size:  8304 byte, filtered stream size:  4184 byte)
SHA1            =  145ms (stream size:  8304 byte, filtered stream size:  4192 byte)
SHA512          =  344ms (stream size:  8304 byte, filtered stream size:  4280 byte)

== CIPHER FILTERS == 1000 iterations
Blowfish        =  898ms (stream size:  8304 byte, filtered stream size:  8304 byte)
Rijndael        =  941ms (stream size:  8304 byte, filtered stream size:  8304 byte)
3TDES           = 1729ms (stream size:  8304 byte, filtered stream size:  8304 byte)
3DES            = 1757ms (stream size:  8304 byte, filtered stream size:  8304 byte)

== COMPRESS FILTERS == 1000 iterations
LZO             =   79ms (stream size:  8304 byte, filtered stream size:  1113 byte)
ZLibCompression =  295ms (stream size:  8304 byte, filtered stream size:   799 byte)

Last speed test is for the only filter included in Delphi2010. It’s included only for compare times and data stream size with the other filters.

After you install DataSnapFiltersCompendium.bpl you will see following filters into the “Filters” property

New filters registered by DSFC
New filters registered by DSFC

Cipher filters have only one property for the encription key

Encryption key for the cipher filters
Encryption key for the cipher filters

Project Source Contains

  • Full Filters Code
  • Unit Test
  • SpeedTest

Download DataSnap Filters Compendium

P.S. I’ll be at ITDevCon… and you? 🙂