OTRecv.py

'''
Created on 08-Dec-2015

@author: pawan
'''
import random
import socket
import hashlib
from generator import euclid, modifiedPower, euclid
import math

class OTRecv():

    def __init__(self,g,p,q):
        self.g = g
        self.p = p
        self.q = q
        self.s = socket.socket()
        self.makeConnection()

    def generateK(self):
        return random.randrange(self.q)
    
    def makeConnection(self):
        self.s.connect(('127.0.0.1', 3000))

    def randomOracle(self, x):
        return int(hashlib.sha256(str(x)).hexdigest(), base=16)
        
    def obliviouslyReceive(self, X,number_of_OT, lam):
        client_socket = self.s
        final = []
        k=random.randrange(1,self.q+1);
        for i in xrange(number_of_OT):
            print i
            c=int(client_socket.recv(200))
            pk=list()
            #print pk
            pk.insert(X[i],modifiedPower(self.g,k,self.q))
            gcd=inv=-1
            while gcd != 1 and inv <= 0 :
                gcd,inv,ui = euclid(modifiedPower(self.g,k,self.q),self.q)
            pk.insert(1-X[i],(c*inv)%self.q)
            client_socket.send(str(pk[0]))
            gr=client_socket.recv(200)
            M0=client_socket.recv(lam)
            M1=client_socket.recv(lam)
            E=[M0,M1]
            grk = modifiedPower(int(gr),k,self.q)
            r_guess0=(hashlib.sha512(str(grk)+str(X[i])).digest())
            f=str(r_guess0)* int(math.ceil(number_of_OT/len(r_guess0))+1)
            T=int(E[X[i]],2)^ord(f[i])
            final.append(T)
        return final