public static int[] DecryptVote(this Vote vote, PrivateKey key)
{
if (vote == null || key == null || vote.EncryptedVector == null)
{
throw new Exception("Can't decrypt vote. Null key or vote");
}
return(vote.EncryptedVector.Select(arg => HomoCrypto.Decrypt(arg, key)).ToArray());
}
private static void Vote(string host, KeyValuePair <User, int[]>[] voters, Guid id, PublicKey publicKey)
{
log.Info("Voting in parallel...");
var candidateTasks = voters.Select(kvp => ElectroClient.VoteAsync(host, Program.PORT, kvp.Key.Cookies, id, HomoCrypto.EncryptVector(kvp.Value, publicKey))).ToArray();
try
{
Task.WaitAll();
log.InfoFormat("Voted by {0} users", voters.Length);
}
catch (Exception e)
{
throw new ServiceException(ExitCode.DOWN, string.Format("Failed to vote by {0} users in parallel: {1}", candidateTasks.Length, e));
}
}
public static int ProcessPut(string host, string id, string flag)
{
log.Info("Processing Vuln2.Put");
var candidateUsers = RegisterCandidates(host, flag.Distinct().Select(c => UsersManager.GenUser(null, c.ToString())).OrderBy(user => user.Login).ToArray());
var election = StartElection(host, candidateUsers[0], false, nominateTimeInSec, voteTimeInSec);
var privateKey = election.PrivateKeyForCandidates;
var sw = Stopwatch.StartNew();
election = NominateUsers(host, election, candidateUsers.Skip(1).ToArray());
sw.Stop();
var tts = nominateTimeInSec * 1000 - sw.ElapsedMilliseconds;
if (tts > 0)
{
log.InfoFormat("Sleeping for {0}ms before voting (nomination duration is {1}s)", tts, nominateTimeInSec);
Thread.Sleep((int)tts);
}
var votes = GenVotes(flag, election);
var voters = RegisterVoters(host, votes, candidateUsers);
log.InfoFormat("Voting by {0} voters", voters.Length);
foreach (var voter in voters)
{
ElectroClient.Vote(host, Program.PORT, voter.Key.Cookies, election.Id, HomoCrypto.EncryptVector(voter.Value, election.PublicKey));
}
log.Info("Voted");
var state = new Vuln2State
{
ElectionId = election.Id.ToString(),
Voter = voters[0].Key,
PrivateKey = privateKey
};
log.Info("Flag put");
Console.Out.WriteLine(Convert.ToBase64String(Encoding.UTF8.GetBytes(state.ToJsonString())));
return((int)ExitCode.OK);
}
public bool TryDecryptElectionResultIfFinished(Election election)
{
if (!election.IsFinished)
{
return(false);
}
PrivateKey privateKey;
if (!electionPrivateKeys.TryGetValue(election.Id, out privateKey))
{
return(false);
}
election.DecryptedResult = (election.EncryptedResult ?? Enumerable.Repeat(BigInteger.Zero, election.Candidates.Count)).Select(voteElement => HomoCrypto.Decrypt(voteElement, privateKey)).ToArray();
return(true);
}
