#CSharpSMCLtoPython

###Brief description This is a translator from [Secure Multiparty Computation Language (SMCL)] (http://www.brics.dk/SMCL/papers/smcl-plas07.pdf) to Python.

Clarification: I'm using a subset of the language described in the paper, see the language details.

It was developed for educational purposes as the final project for the Implementation of Programming Languages 2013/2014 University of Genoa course.

###Tools The project was developed using:

• [GPLEX] (https://gplex.codeplex.com/) to generate the scanner using the LEX specification language
• [GPPG] (https://gppg.codeplex.com/) to generate the parser using YACC-like syntax
• [Visual Studio 2013] (http://www.visualstudio.com/) as IDE for the translator
• [ReSharper] (http://www.jetbrains.com/resharper/) as holy hand!
• [Eclipse] (https://www.eclipse.org/) Kepler with [PyDev] (http://pydev.org/) plugin for debug the Python generated code

###The XML configuration file In the xml file you need to specify:

• the numeric id
• the name (that must match with its definition in the smcl source)
• the hostname and port (because processes communicate through the network)

For each entry you implicitly defines the number of participants.

For example:

	<?xml version='1.0' encoding='utf-8'?>
	<smcxml>
		<player id='0' name='Max' host='127.0.0.1' port='1337'/>
		<player id='1' name='Millionaires' host='127.0.0.1' port='1234'/>
		<player id='2' name='Employees' host='127.0.0.1' port='1235'/>
	</smcxml>

###How it works It need 3 command line arguments:

./CSharpSMCLtoPython.exe -i inputFile.smcl -o outputFolder -x xmlConfig.xml

and it generates two files: smclClient.py and smclServer.py in outputFolder.

First: run the server without arguments.

python smclServer.py

Then run the clients specifying the numeric id (relative to the xml configuration).

python smclClient.py [0-9]+

###Language details I think that LEX and YACC syntax it's intuitive and self-explicative to understand, so the best (and updated) documentation is the source:

• [SMCLscanner.l] (https://github.com/simoneaonzo/CSharpSMCLtoPython/blob/master/CSharpSMCLtoPython/ASTbuilder/SMCLscanner.l)
• [SMCLparser.y] (https://github.com/simoneaonzo/CSharpSMCLtoPython/blob/master/CSharpSMCLtoPython/ASTbuilder/SMCLparser.y)

###Criticism Even though this is my first experience in the world of compilers I'm not satisfied with the feature of my language and my compiler's complexity. I lost much time to set up [viff] (http://viff.dk/) for the cryptographic primitives that should have been used by the python generated code, in the toy examples seemed the right choice, but due to the asynchronous nature (viff uses twisted) it was a waste of time. So, this project was simply an exercise to improve my programming skills and understand the magic that's behind ompilers!