Board index » delphi » Compressing and encrypting SOAP messages

2005-06-30 08:05:07 PM
delphi239
Has anyone had any success with compressing and encrypting the SOAP data
just before it goes down the wire? I understand that one is supposed to
perform this in the BeforeExecute and AfterExecute events but something
seems to stop it.
 

Mischa Simmonds writes:
www.agnisoft.com/white_papers/advancedws/default.asp
--
Deepak Shenoy (TeamB)
Agni Software (www.agnisoft.com)
Blog: shenoyatwork.blogspot.com
 

I took a quick look at the article. I don't see where the data is going from
the file to the array... so I am assuming that the array is holding the entire
file. This would be silly for large files and would peg server memory, as well
as client memory.
I recommend another approach.
Build a TStream like interface as a web service, then use a TStream wrapper
around the interface. That way you can download the file in chunks and file
transfers might look something like this:
RemoteFile:= MyWebService.GetFile(FileName);
StreamWrapper:= TStreamWrapper.Create(RemoteFile);
LocalFile:= TFileStream.Create('C:\Temp\BlaBla.xyz', fmCreate);
LocalFile.CopyFrom(StreamWrapper, 0);
-Bill
"Deepak Shenoy (TeamB)" <XXXX@XXXXX.COM>writes

Deepak Shenoy (TeamB) writes:
problem is with BeforeExecute on the client side. It uses WideString,
not TStream, so any NULL in the data is going to be a problem. Any
compressed or encrypted data is bound to have a NULL in there somewhere.
So, I can compress/encrypt from the server to the client, but not the
other way round!!
procedure TForm1.HTTPRIO1BeforeExecute(const MethodName: String; var
SOAPRequest: WideString);
 

William Egge writes:
to a file or database or whatever.
--
Deepak Shenoy (TeamB)
Agni Software (www.agnisoft.com)
Blog: shenoyatwork.blogspot.com
 

Ahh..Sorry, I didn't connect your name to being the author of the
article. Thanks for that, it has given me a few ideas. But my comments
still stand. With WideString being utilised in the BeforeExecute on the
client side, the compression/encryption can only be one way.
Deepak Shenoy (TeamB) writes:

Mischa Simmonds writes:
1) Write a descendant component from THttpRio (call it THTTPRioEnh)
2) Declare a type like so:
TBeforeExecuteStreamEvent = procedure(const MethodName: string; Request
: TStream) of object;
3) In the THTTPRioEnh class, declare a published variable of type:
property OnBeforeExecuteStream: TBeforeExecuteStreamEvent read
FOnBeforeExecuteStream write FOnBeforeExecuteStream;
Hit Ctrl+Shift+C. The private variable should get declared
automatically.
4) override the DoBeforeExecute procedure and in it put:
procedure DoBeforeExecute(const MethodName: string; Request: TStream);
begin
inherited DoBeforeExecute(MethodName: string; Request: TStream);
if Assigned( FOnBeforeExecuteStream ) then
FOnBeforeExecuteStream( MethodName, Request );
end;
Then register and all that stuff.
You can then assign a handler to OnbeforeExecutestream of this
inherited component.
I am lazy, so I did all this in Rio.Pas and instead of creating a
handler in the IDE I set this up in code instead, something like:
HTTPRio1.OnBeforeExecuteStream := BeforeExecuteStream;
Where I do the modifications to the request stream.
Hope this helps,
--
Deepak Shenoy (TeamB)
Agni Software (www.agnisoft.com)
Blog: shenoyatwork.blogspot.com
 

Mischa Simmonds writes:
kind of response handler.
--
Deepak Shenoy (TeamB)
Agni Software (www.agnisoft.com)
Blog: shenoyatwork.blogspot.com
 

After reading your article I have used yor method of compressing soap and
it is a fantastic increase in performance when recieving responses thankyou,
however I have been trying to apply the same compression to the request and
I can't seem to Decompress the request on the server side.
I have tried overriding the pascalinvoker.invoke method and pretty much any
method I can find that would appear to be a good place to start but it just
won't work.
Have you or anyone else managed to get round this at all?
thanks again
jim
"Deepak Shenoy (TeamB)" <XXXX@XXXXX.COM>writes

james rimell writes:
get my project over...
Cheers,
--
Deepak Shenoy (TeamB)
Blog: shenoyatwork.blogspot.com
 

That would be great
my email is as follows....
jrimell at vecta dot net
thanks
"Deepak Shenoy (TeamB)" <XXXX@XXXXX.COM>writes

can i have a copy as well please.
--
please remove _1 from email address.
"After all, what is education but a process by which a person begins to
learn how to learn?" Peter Ustinov Dear Me(1977)
"Deepak Shenoy (TeamB)" <XXXX@XXXXX.COM>writes

And a copy for me please. can not wait.
PS: I am actually a C++Builder user. So I can only have as much Pascal
as C++Builder can take ;-)
I notice some comments that ZLIB is available for Delphi users, but it
is not available for C++Builder. I have been using it anyway, but when I
read a memory buffer I have avoid a little of the header.
xtcsuk writes:

Sorry, my email adress is mischa at informationdesign dot com dot au
Thanks
xtcsuk writes:

Had a look at this. But I'd have suspected that you would need to
overide "function THTTPReqResp.Send(const S: WideString): Integer;" in
SOAPHTTPTrans.pas which calls HttpSendRequest (wininet.pas), as it is
expecting a WideString as well, as well as the UTF8Encode function.
Deepak Shenoy (TeamB) writes: