/// <summary>
/// Creates a new ballot for a voter.
/// </summary>
/// <param name="vota">Vota the voter wishes to cast for each option.</param>
/// <param name="parameters">Cryptographic parameters.</param>
/// <param name="publicKey">Public key of voting authorities.</param>
/// <param name="progress">Report progress up.</param>
public Ballot(IEnumerable<int> vota, BaseParameters parameters, Question questionParameters, BigInt publicKey, Progress progress)
{
if (progress == null)
throw new ArgumentNullException("progress");
if (vota == null)
throw new ArgumentNullException("vota");
if (parameters == null)
throw new ArgumentNullException("parameters");
if (publicKey == null)
throw new ArgumentNullException("publicKey");
if (vota.Count() != questionParameters.Options.Count())
throw new ArgumentException("Bad vota.");
if (!vota.All(votum => votum.InRange(0, 1)))
throw new ArgumentException("Bad vota.");
if (vota.Sum() != questionParameters.MaxVota)
throw new ArgumentException("Bad vota.");
Votes = new List<Vote>();
BigInt nonceSum = new BigInt(0);
Vote voteSum = null;
List<Tuple<int, BigInt, BaseParameters, BigInt>> voteWorkList = new List<Tuple<int, BigInt, BaseParameters, BigInt>>();
foreach (int votum in vota)
{
BigInt nonce = parameters.Random();
nonceSum += nonce;
voteWorkList.Add(new Tuple<int, BigInt, BaseParameters, BigInt>(votum, nonce, parameters, publicKey));
}
progress.Down(1d / (vota.Count() + 1) * vota.Count());
List<Vote> voteList = Parallel
.Work<Tuple<int, BigInt, BaseParameters, BigInt>, Vote>(CreateVote, voteWorkList, progress.Set);
progress.Up();
foreach (Vote vote in voteList)
{
voteSum = voteSum == null ? vote : voteSum + vote;
Votes.Add(vote);
}
progress.Down(1d / (double)(vota.Count() + 1));
SumProves = new List<Proof>();
for (int proofIndex = 0; proofIndex < parameters.ProofCount; proofIndex++)
{
SumProves.Add(new Proof(nonceSum * 12, voteSum, publicKey, parameters));
progress.Add(1d / (double)parameters.ProofCount);
}
progress.Up();
}
/// <summary>
/// Adds a vote to the vote sum.
/// </summary>
/// <remarks>
/// Verfies the correctness of the vote first.
/// </remarks>
/// <param name="envelopeIndex">Index of the envelope.</param>
/// <param name="signedEnvelope">Signed envelope from voter.</param>
/// <param name="progress">Report the progress of the tallying.</param>
public void Add(int envelopeIndex, Signed<Envelope> signedEnvelope, Progress progress)
{
if (signedEnvelope == null)
throw new ArgumentNullException("signedEnvelope");
if (voteSums == null)
throw new InvalidOperationException("Must call TallyBegin first.");
CryptoLog.Begin(CryptoLogLevel.Detailed, "Tallying envelope");
CryptoLog.Add(CryptoLogLevel.Detailed, "Envelope index", envelopeIndex);
CryptoLog.Add(CryptoLogLevel.Detailed, "Certificate id", signedEnvelope.Certificate.Id);
CryptoLog.Add(CryptoLogLevel.Numeric, "Certificate fingerprint", signedEnvelope.Certificate.Fingerprint);
CryptoLog.Add(CryptoLogLevel.Detailed, "Certificate type", signedEnvelope.Certificate.TypeText);
if (signedEnvelope.Certificate is VoterCertificate)
{
CryptoLog.Add(CryptoLogLevel.Detailed, "Certificate group id", ((VoterCertificate)signedEnvelope.Certificate).GroupId);
}
bool acceptVote = true;
Envelope envelope = signedEnvelope.Value;
//Certificate is of voter and valid for that canton.
acceptVote &= signedEnvelope.Certificate is VoterCertificate &&
((VoterCertificate)signedEnvelope.Certificate).GroupId == this.parameters.GroupId;
//Signature must be valid.
acceptVote &= signedEnvelope.Verify(this.certificateStorage, envelope.Date);
CryptoLog.Add(CryptoLogLevel.Detailed, "Certificate status", signedEnvelope.Certificate.Validate(this.certificateStorage, envelope.Date).Text());
CryptoLog.Add(CryptoLogLevel.Detailed, "Envelope signature", signedEnvelope.Verify(this.certificateStorage, envelope.Date));
//Voter's vote must not have been counted.
acceptVote &= !this.countedVoters.Contains(signedEnvelope.Certificate.Id);
CryptoLog.Add(CryptoLogLevel.Detailed, "Already voted", this.countedVoters.Contains(signedEnvelope.Certificate.Id));
//Date must be in voting period.
acceptVote &= envelope.Date.Date >= this.parameters.VotingBeginDate;
acceptVote &= envelope.Date.Date <= this.parameters.VotingEndDate;
CryptoLog.Add(CryptoLogLevel.Detailed, "Envelope date", envelope.Date);
//Ballot must verify (prooves).
for (int questionIndex = 0; questionIndex < this.parameters.Questions.Count(); questionIndex++)
{
Question question = this.parameters.Questions.ElementAt(questionIndex);
Ballot ballot = envelope.Ballots.ElementAt(questionIndex);
progress.Down(1d / (double)this.parameters.Questions.Count());
acceptVote &= ballot.Verify(this.publicKey, this.parameters, question, this.rng, this.proofCheckCount, progress);
progress.Up();
}
CryptoLog.Add(CryptoLogLevel.Detailed, "Envelope accepted", acceptVote);
CryptoLog.EndWrite();
lock (this.envelopeSequencerList)
{
this.envelopeSequencerList.Add(envelopeIndex, new Tuple<Signed<Envelope>,bool>(signedEnvelope, acceptVote));
}
AddInSequence();
}
