SRTP design thoughts and some general implementation

Hi Su,

Regarding the discussion on the IRC channel, here is a link
from  
Kensan that might be of your interest: http://sourceforge.net/ 
mailarchive/message.php? 
msg_id=444a31a20610130953o5d9d016cxabbe9e2813f3ca41%40mail.g
mail.com

Cheers,
romain

On 2007/05/07, at 23:44, Bing Su wrote:

> Hi, all
>
> Recently I did some design and implementation of the
SRTP project's  
> architecture. I'd like to share my thoughts with you.

>
> OK, here's my design:
> 1. The srtp support will be based on JMF's RTP support.
We will  
> translate each RTP packets into SRTP packets before
they are sent out.
> And translate received SRTP packets into normal RTP
packets before  
> they are forwarded to JMF.
> This means we only perform the translation between RTP
and SRTP.  
> Normal RTP's work is still done by JMF, such as jitter
buffer control.
>
> 2. JMF allow developer to specify the transport of RTP
packets. The  
> RTPConnector interface is design for this purpose.
> JMF will write outgoing packets through RTPConnector
and read  
> incoming packets from RTPConnector.
> So, by implementing the RTPConnector interface, we
could intercept  
> the outgoing/incoming RTP/RTCP packets and then do our
encryption/ 
> decryption work.
>
> 3.The encryption/decryption is actually a
transformation of RTP  
> packets. So, we can first define a general class
"TransformConnector".
> And then specify the transforming logic through
interface  
> "PacketTransformer". Each implementation of
"PacketTransformer"  
> contains
> the concrete logic of how the packets will be
manipulated. In our  
> case, we will encapsulate our encryption/decryption
logic in  
> "SRTPTransformer".
>
> 4. TransformConnector and related support class such as
 
> TransformInputStream / TransformOutputStream deals with
abstract  
> PacketTransformer interface.
> When a packet is ready to be sent, it will be handed to
 
> PacketTransformer, after transformation, the returned
packet (maybe  
> complete new one) will then be sent out.
> When a packet is received, it will fist handed to
PacketTransformer  
> for reverse transformation, and then the returned
packet will be  
> handed to JMF for later processing.
>
> Here's the implementation status:
>
> 1. I finished a minimal implementation of the above
design. And  
> created a dummy transformer (does nothing, returns the
packet to be  
> transformed directly)
> 2. I modified JMF's example code and make a small test
program, to  
> test the dummy transformer (and the
TransformConnector). In my  
> environment, it works fine.
> The core modification is instead of initialize
RTPManager using  
> local address and add remote address as target, we pass
our  
> TransformerConnector object to
> the initialize() method of RTPManager.
> 3. I use eclipse 3.2.2 as my IDE. JMF's version is
2.1.1e.
> Coding styles and project related regulations are not
considered so  
> much, will be refactored later.
> 4. Because currently project repository is not set up,
so the  
> project is packed into a zip, attached with this
email.
> If this is not suitable for mailing list, will somebody
tell me?  
> Thank you.
> 5. Wish this piece of code can make you understand my
thoughts a  
> little easier. :-D
>
> Thank you,
> Su
> <srtp4jmf.zip>
>
------------------------------------------------------------
---------
> To unsubscribe, e-mail: dev-unsubscribesip-communicator.dev.java.net
> For additional commands, e-mail: dev-helpsip- 
> communicator.dev.java.net

-- 
Romain KUNTZ
kuntzclarinet.u-strasbg.fr
Louis Pasteur University - Networks and Protocols Team



------------------------------------------------------------
---------
To unsubscribe, e-mail: dev-unsubscribesip-communicator.dev.java.net
For additional commands, e-mail: dev-helpsip-communicator.dev.java.net

Hi Su,

Thank you for the roadmap. This reflects what we discussed
on IRC  
last time.
BTW, would you like an account on the SIP Communicator's
Wiki? The  
wiki may be a more efficient tool to maintain your roadmap,
and would  
avoid the word->pdf->ML procedure.

This comments also applies to other GSoC students. Raise
your hand if  
you're interested!

Thanks,
romain

On 2007/05/15, at 9:54, Bing Su wrote:

> Hi all,
>
> I've updated my roadmap according to previous
discussion.
> Because I find plain text roadmap hard to maintain, I
switched to  
> word, and thus converted it to a pdf.
> It is attached with this email, take a look if you are
interested. 
> Of course it is not the final one, it will be updated
as this  
> project goes on.
>
> Best regards,
> Su
> <roadmap.pdf>
>
------------------------------------------------------------
---------
> To unsubscribe, e-mail: dev-unsubscribesip-communicator.dev.java.net
> For additional commands, e-mail: dev-helpsip- 
> communicator.dev.java.net

-- 
Romain KUNTZ
kuntzclarinet.u-strasbg.fr
Louis Pasteur University - Networks and Protocols Team



------------------------------------------------------------
---------
To unsubscribe, e-mail: dev-unsubscribesip-communicator.dev.java.net
For additional commands, e-mail: dev-helpsip-communicator.dev.java.net

Hi Su,

Emil has created an account for you on the Wiki.
You can access the Wiki from this page (click on the
"Roadmap" link  
beside your name):
http://www.sip-communicator.org/index.php/Development/

TeamAndContributors

I'll send you a private mail about your login details.

Thanks,
romain

On 2007/05/15, at 14:01, Bing Su wrote:

> Sure! It will be definitely great to maintain the
roadmap through  
> wiki.
> So, where is it? I searched for it, but only found an
empty one at:  
> http://wiki.java.net/bin/view/Communications/SipComm
unicator .
>
> Thank you,
> Su
>
> On 5/15/07, Romain KUNTZ <kuntzclarinet.u-strasbg.fr> wrote: Hi Su,
>
> Thank you for the roadmap. This reflects what we
discussed on IRC
> last time.
> BTW, would you like an account on the SIP
Communicator's Wiki? The
> wiki may be a more efficient tool to maintain your
roadmap, and would
> avoid the word->pdf->ML procedure.
>
> This comments also applies to other GSoC students.
Raise your hand if
> you're interested!
>
> Thanks,
> romain
>
> On 2007/05/15, at 9:54, Bing Su wrote:
>
> > Hi all,
> >
> > I've updated my roadmap according to previous
discussion.
> > Because I find plain text roadmap hard to
maintain, I switched to
> > word, and thus converted it to a pdf.
> > It is attached with this email, take a look if you
are  
> interested. 
> > Of course it is not the final one, it will be
updated as this
> > project goes on.
> >
> > Best regards,
> > Su
> > <roadmap.pdf>
> >  
>
------------------------------------------------------------
---------
> > To unsubscribe, e-mail: dev-unsubscribesip- 
> communicator.dev.java.net
> > For additional commands, e-mail: dev-helpsip-
> > communicator.dev.java.net
>
> --
> Romain KUNTZ
> kuntzclarinet.u-strasbg.fr
> Louis Pasteur University - Networks and Protocols Team
>
>
>
>
------------------------------------------------------------
---------
> To unsubscribe, e-mail: dev-unsubscribesip-communicator.dev.java.net
> For additional commands, e-mail: dev-helpsip- 
> communicator.dev.java.net
>
>

-- 
Romain KUNTZ
kuntzclarinet.u-strasbg.fr
Louis Pasteur University - Networks and Protocols Team



------------------------------------------------------------
---------
To unsubscribe, e-mail: dev-unsubscribesip-communicator.dev.java.net
For additional commands, e-mail: dev-helpsip-communicator.dev.java.net

Hi Romain,

I've logged in, changed my password and upload the roadmap
with no problem.
Thank you. This wiki approach is really much more
convenient. 

Cheers,
Su

On 5/16/07, Romain KUNTZ <kuntzclarinet.u-strasbg.fr>
wrote:
> Hi Su,
>
> Emil has created an account for you on the Wiki.
> You can access the Wiki from this page (click on the
"Roadmap" link
> beside your name):
> http://www.sip-communicator.org/index.php/Development/

> TeamAndContributors
>
> I'll send you a private mail about your login details.
>
> Thanks,
> romain
>
> On 2007/05/15, at 14:01, Bing Su wrote:
>
> > Sure! It will be definitely great to maintain the
roadmap through
> > wiki.
> > So, where is it? I searched for it, but only found
an empty one at:
> > http://wiki.java.net/bin/view/Communications/SipComm
unicator .
> >
> > Thank you,
> > Su
> >
> > On 5/15/07, Romain KUNTZ <kuntzclarinet.u-strasbg.fr> wrote: Hi Su,
> >
> > Thank you for the roadmap. This reflects what we
discussed on IRC
> > last time.
> > BTW, would you like an account on the SIP
Communicator's Wiki? The
> > wiki may be a more efficient tool to maintain your
roadmap, and would
> > avoid the word->pdf->ML procedure.
> >
> > This comments also applies to other GSoC students.
Raise your hand if
> > you're interested!
> >
> > Thanks,
> > romain
> >
> > On 2007/05/15, at 9:54, Bing Su wrote:
> >
> > > Hi all,
> > >
> > > I've updated my roadmap according to previous
discussion.
> > > Because I find plain text roadmap hard to
maintain, I switched to
> > > word, and thus converted it to a pdf.
> > > It is attached with this email, take a look
if you are
> > interested. 
> > > Of course it is not the final one, it will be
updated as this
> > > project goes on.
> > >
> > > Best regards,
> > > Su
> > > <roadmap.pdf>
> > >
> >
------------------------------------------------------------
---------
> > > To unsubscribe, e-mail: dev-unsubscribesip-
> > communicator.dev.java.net
> > > For additional commands, e-mail: dev-helpsip-
> > > communicator.dev.java.net
> >
> > --
> > Romain KUNTZ
> > kuntzclarinet.u-strasbg.fr
> > Louis Pasteur University - Networks and Protocols
Team
> >
> >
> >
> >
------------------------------------------------------------
---------
> > To unsubscribe, e-mail: dev-unsubscribesip-communicator.dev.java.net
> > For additional commands, e-mail: dev-helpsip-
> > communicator.dev.java.net
> >
> >
>
> --
> Romain KUNTZ
> kuntzclarinet.u-strasbg.fr
> Louis Pasteur University - Networks and Protocols Team
>
>
>
>
------------------------------------------------------------
---------
> To unsubscribe, e-mail: dev-unsubscribesip-communicator.dev.java.net
> For additional commands, e-mail: dev-helpsip-communicator.dev.java.net
>
>

------------------------------------------------------------
---------
To unsubscribe, e-mail: dev-unsubscribesip-communicator.dev.java.net
For additional commands, e-mail: dev-helpsip-communicator.dev.java.net