Hi, guys!
I want to get user data from the GPRS networking using HTTP protocol. But the server request the authentication using digest.

I looked up in the Symbian SDK documentation and found the "MHTTPAuthenticationCallback" may do this work.

I inherented the class and implemented the GetCredentialsL function. But when i send the "GET" operation to the server, the server give a response of "401" message, but the program don't do nothing and GetCredentialsL method is also not called.

So i want someone give some suggestions or why it doesn't work.
Thanks in advance!
My code snippet is followed below:
void CHttpHandler::ConstructL()

void CHttpHandler::SendGetL( const TDesC8& aURI, const TDesC8& aETag)
	TUriParser8 uriParser;
	uriParser.Parse( aURI);
	RStringF getMethod = iSession.StringPool().StringF(HTTP::EGET, RHTTPSession::GetTable());
	iTransaction = iSession.OpenTransactionL( uriParser, *this, getMethod);
	RHTTPHeaders hdr = iTransaction.Request().GetHeaderCollection();

	if ( aETag != KNullDesC8)
		SetHeaderL( hdr, HTTP::EIfMatch, aETag);
	SetHeaderL( hdr, KXCAPIden, iUserUri);


TBool CHttpHandler::GetCredentialsL( const TUriC8& aURI, RString aRealm, RStringF aAuthenticationType, RString& aUsername, RString& aPassword)
	TBuf<KURIBufferSize> authType;
	TBuf<KURIBufferSize> uri;
	TBuf<KDefaultBufferSize> authText;
	_LIT(KAuthRequired, "%S requires %S authentication.");
	authText.Format(KAuthRequired, &uri, &authType);
	_LIT(KAuthNote, "Authentication required.");
	RLog::Log( KAuthNote );

	TBuf8<KDefaultBufferSize> userName;
	TBuf8<KDefaultBufferSize> password;
	_LIT8(KUserName, "sip:user7@example.com");
	_LIT8(KPswd, "123");
	userName = KUserName();
	password = KPswd();
	TBuf8<KDefaultBufferSize> temp;
	TRAPD(err, aUsername = aRealm.Pool().OpenStringL(temp));
	if (!err)
		TRAP(err, aPassword = aRealm.Pool().OpenStringL(temp));
		if (!err)
			return ETrue;
	return EFalse;