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CSslSocket - SSL/TLS enabled CSocket

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24 Nov 20012 min read 829.8K   11.1K   83   136
CSocket derived class with SSL/TLS extension

Motivation

Having seen SSL samples from Platform SDK (WebServer and WebClient) I found, it would be useful to benefit from SSL/TLS functionality built in Windows. However, these samples are not very user friendly - you can learn from them how SSL/TLS works in Windows, but adapt it to different applications is not easy.

Description of solution

I am sure everybody knows CSocket from MFC and has seen samples CHATTER / CHATSRVR - that's place where I started - my idea was to derive CSslSocket from CSocket and extend it with SSL functionality.

It means that CSslSocket works in the same way as CSocket and there are several small differences in the declarations of Create() and Listen() methods:

BOOL Create(
	UINT nSocketPort = 443,
	LPCTSTR lpszSocketAddress = NULL,
	const TCHAR *szCertName = NULL,
	BOOL bMachineStore = FALSE,
	DWORD dwProtocol = 0);
BOOL Listen(
	int nConnectionBacklog = 5,
	BOOL bAuthClient = FALSE);

Parameters nSocketPort, lpszSocketAddress are the same parameters as CSocket has. SSL/TLS are a stream based protocols, therefore you cannot specify SOCK_DGRAM in this method as it is possible for CSocket. However, you can specify name of certificate (you must have certificate for server side), certificate store  and preferred protocol (see SCHANNEL_CRED). Client certificate is not required, but you can force SSL engine to require it. In this case set bAuthClient to TRUE in call to Listen() method.

You can find more information about SSL/TLS and Schannel at locations specified at the begging of the article.

Usage

You can use CSslSocket exactly as you are using CSocket, use it directly, or derive your new class from CSslSocket and overwrite required method. See modified samples provided with this article.

Demo program(s)

There are modified samples from Microsoft CHATTER / CHATSRVR for demonstration of CSslSocket usage and work in the zipped file. Modifications are small - just CSocket is replaced with CSslSocekt and there is code to pass proper parameters to the CSslSocket class. You need one or two certificates to test my class. Simplest way is to install Certificate services from Microsoft and request certificates for client and server identification by web forms provided by Certificate services (you need Windows NT/2000 server), or you can use OpenSSL as well. Then just specify server certificate name for CHATSRVR  in the first dialog window and user certificate name for CHATTER.

License

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here


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Comments and Discussions

 
QuestionThe second InitializeSecurityContext in ClientHandshakeLoop always fails! Pin
BasavarajGoudaH15-Aug-20 19:42
BasavarajGoudaH15-Aug-20 19:42 
QuestionBUG : EXTRA_BUFFER is not well managed Pin
Guillaume Waser5-Jul-18 20:22
Guillaume Waser5-Jul-18 20:22 
QuestionLicense Pin
talbot4-Jul-11 0:21
talbot4-Jul-11 0:21 
QuestionHow to enable TLS? Pin
StefanKittel13-Dec-09 11:29
StefanKittel13-Dec-09 11:29 
AnswerRe: How to enable TLS? Pin
Art Joyce3-Feb-12 4:04
Art Joyce3-Feb-12 4:04 
QuestionDoes Schannel support DTLS protocol? Pin
D L Deepthi7-Dec-08 19:37
D L Deepthi7-Dec-08 19:37 
QuestionDecryptMessage fails with SEC_E_DECRYPT_FAILURE (0x80090330L) error Pin
deepthi_dl23-Sep-08 4:16
deepthi_dl23-Sep-08 4:16 
GeneralLarge message will hangs the server Pin
pip.chan6-May-08 21:20
pip.chan6-May-08 21:20 
GeneralRe: Large message will hangs the server Pin
pip.chan6-May-08 22:43
pip.chan6-May-08 22:43 
GeneralRe: Large message will hangs the server Pin
pip.chan7-May-08 0:09
pip.chan7-May-08 0:09 
QuestionServer requests client cert problem ? Pin
Michael Chourdakis24-Nov-07 5:56
mvaMichael Chourdakis24-Nov-07 5:56 
QuestionServer-auth-only with exportable public cert. & .PVK file Pin
BritannicAndy2-Aug-07 1:45
BritannicAndy2-Aug-07 1:45 
Questionerror 0x80090304 Pin
dpfairchild4-May-07 11:19
dpfairchild4-May-07 11:19 
AnswerRe: error 0x80090304 Pin
isapiyan16-May-07 15:53
isapiyan16-May-07 15:53 
Generalerror in CSslSocket::ClientHandshakeLoop. Pin
Mazhar Nazeer22-Nov-06 2:04
professionalMazhar Nazeer22-Nov-06 2:04 
GeneralSchannel offline decryption Pin
abhalve28-Sep-06 21:11
abhalve28-Sep-06 21:11 
Questionalways return find not found Pin
tin nguyen trung24-Sep-06 6:27
tin nguyen trung24-Sep-06 6:27 
QuestionHow to implement on windows 2003 Pin
tin nguyen trung23-Sep-06 5:02
tin nguyen trung23-Sep-06 5:02 
GeneralStack Corruption Pin
I.C.Wiener19-Mar-06 11:32
I.C.Wiener19-Mar-06 11:32 
GeneralRe: Stack Corruption Pin
ncranger6-Apr-06 22:50
ncranger6-Apr-06 22:50 
QuestionMartin - You Still Around? Pin
mjxnjx21-Mar-05 12:35
mjxnjx21-Mar-05 12:35 
GeneralLDAP TLS connection Pin
meghan20-Jan-05 0:50
meghan20-Jan-05 0:50 
GeneralRoot CA certificate Pin
stanr14-Sep-04 3:49
stanr14-Sep-04 3:49 
GeneralBug in extra data handligh Pin
Irek Zielinski24-Jul-04 22:38
Irek Zielinski24-Jul-04 22:38 
Hi Smile | :)
CSslSocket::Receive function has a bug.

if (pExtraBuffer) {<br />
MoveMemory(m_pbIoBuffer, pExtraBuffer->pvBuffer, pExtraBuffer->cbBuffer);<br />
m_cbIoBuffer = pExtraBuffer->cbBuffer;<br />
continue;<br />
}


"continue;" at the end of this part of code is not correct. You should attempt to decrypt this part of message instead of trying to download more in next pass of do-while loop. It quickly leads to errors when there is no more data to receive.
Also I noticed some crash of your code when receiving a big ammounts of data (it happens sometimes, I wans not able to find a solution so far).

Best regards and thanks for your work Smile | :)
Irek

Check out my software at: http://www.ireksoftware.com
GeneralRe: Bug in extra data handligh Pin
Darkstructures4-Apr-05 22:01
Darkstructures4-Apr-05 22:01 

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