public static Election NominateUsers(string host, Election election, User[] candidates)
{
log.InfoFormat("Nominating rest {0} candidates for election...", candidates.Length);
var nominateTasks = candidates.Select(candidate => new { candidate, task = ElectroClient.NominateAsync(host, Program.PORT, candidate.Cookies, election.Id) }).ToArray();
Election[] elections;
try
{
elections = nominateTasks.Select(arg => arg.task.Result).ToArray();
}
catch(Exception e)
{
throw new ServiceException(ExitCode.DOWN, string.Format("Failed to nominate {0} candidates in parallel: {1}", nominateTasks.Length, e));
}
var electionId = election.Id;
election = elections.FirstOrDefault(election1 => election1 != null && election1.Candidates.Count >= candidates.Length + 1);
if(election == null)
throw new ServiceException(ExitCode.MUMBLE, string.Format("Nominated '{0}' candidates for election '{1}', but got less in result", candidates.Length + 1, electionId));
log.Info("Candidates nomindated");
return election;
}
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;
}
public Guid StartElection(string electionName, User firstCandidate, bool isPublic, DateTime nominateTill, DateTime till)
{
var homoKeyPair = HomoKeyPair.GenKeyPair(MaxVotesPerElection);
var election = new Election
{
Id = Guid.NewGuid(),
Name = electionName,
NominateTill = nominateTill,
VoteTill = till,
PublicKey = homoKeyPair.PublicKey,
Votes = new List<Vote>(),
Candidates = new List<CandidateInfo> { CandidateInfo.Create(firstCandidate) },
IsPublic = isPublic
};
statePersister.SaveKey(election.Id, homoKeyPair.PrivateKey);
lock (electionsList)
{
electionPrivateKeys[election.Id] = homoKeyPair.PrivateKey;
electionsDict[election.Id] = election;
electionsList.AddFirst(election);
while(electionsList.Count > MaxElections)
{
var node = electionsList.Last;
Election dummy;
electionsDict.TryRemove(node.Value.Id, out dummy);
electionsList.RemoveLast();
}
}
return election.Id;
}
public static ElectionPublicCore Create(Election election)
{
return new ElectionPublicCore
{
Id = election.Id,
Name = election.Name,
NominateTill = election.NominateTill,
VoteTill = election.VoteTill,
Winner = election.FindWinner()
};
}
private static int[][] GenVotes(string flag, Election election)
{
var candidateInfos = election.Candidates.ToArray();
var votes = flag.Select(c =>
{
var votePos = candidateInfos.IndexOf(info => info.PublicMessage == c.ToString());
if(votePos < 0)
throw new ServiceException(ExitCode.MUMBLE, "Nominated candidates for all flag characters but in resulting election have not for all");
return Utils.GenVoteVector(candidateInfos.Length, votePos);
}).ToArray();
return votes;
}
private static string ExtractFlag(Election election, PrivateKey privateKey, int flagLen)
{
if(election.Votes == null)
throw new ServiceException(ExitCode.CORRUPT, "Election has no votes");
if(election.Candidates == null)
throw new ServiceException(ExitCode.CORRUPT, "Election has no candidates");
return string.Join("", election.Votes.Take(flagLen).Select(vote =>
{
var decryptedVote = vote.DecryptVote(privateKey);
int candidateNum = decryptedVote.IndexOf(i => i > 0);
if(candidateNum < 0 || candidateNum >= election.Candidates.Count)
throw new ServiceException(ExitCode.CORRUPT, string.Format("Election has no candidate corresponding to vector {0}", string.Join(",", decryptedVote)));
return election.Candidates[candidateNum].PublicMessage;
}));
}
