func HandelSignatureRequest(data []byte, c net.Conn) {
var r msgs.SignatureRequest
err := proto.Unmarshal(data, &r)
if err != nil {
fmt.Println("server error reading SignatureRequest:", err)
server.ConnectionError(c)
return
}
err = msg.ValidateSignatureRequest(&r)
if err != nil {
fmt.Println(err)
return
}
keyString := keys.StringKey(r.VoterPublicKey)
if !sign.CheckSig(voterListKey, []byte(keyString), r.KeySignature) {
fmt.Println("SignatureRequest's KeySignature Signature is invalid")
server.ConnectionError(c)
return
}
responseData := getResponse(keyString, &r)
server.SendBlock(msg.SignatureResponse, responseData, c)
}
// Does not check keySignature
func ValidateSignatureRequest(m *msgs.SignatureRequest) error {
newBlindedBallot := m.BlindedBallot
newSig := m.VoterSignature
key := keys.UnpackKey(m.VoterPublicKey)
if !sign.CheckSig(key, newBlindedBallot, newSig) {
return fmt.Errorf("SignatureRequest's VoterSignature Signature is invalid")
}
return nil
}
func SubmitBallot(ballot, sig []byte) (*msgs.VoteResponse, error) {
fmt.Printf("Casting Ballot: %s\n", ballot)
conn, err := net.Dial("tcp", "localhost"+msg.Service)
if err != nil {
return nil, err
}
var vote msgs.Vote
vote.Ballot = ballot
vote.BallotSignature = sig
// redundant sanity check signature
err = msg.ValidateVote(ballotKey, &vote)
if err != nil {
return nil, err
}
data, err := proto.Marshal(&vote)
if err != nil {
return nil, err
}
err = msg.WriteBlock(conn, msg.Vote, data)
if err != nil {
return nil, err
}
t, err := msg.ReadType(conn)
if err != nil {
return nil, err
}
if t != msg.VoteResponse {
return nil, fmt.Errorf("invalid response type")
}
data, err = msg.ReadBlock(conn, maxLength)
conn.Close()
if err != nil {
return nil, err
}
var response msgs.VoteResponse
err = proto.Unmarshal(data, &response)
if err != nil {
fmt.Println("error reading VoteResponse:", err)
return nil, err
}
b := response.BallotEntry
s := response.BallotEntrySignature
if !sign.CheckSig(voteKey, b, s) {
err = fmt.Errorf("illegal vote response from server. Signature in BallotEntry is invalid")
return nil, err
}
fmt.Printf("Got signed BallotEntry for: %s\n", ballot)
return &response, nil
}
func CheckKeySig(privateInfo *msgs.VoterData) SignatureStatus {
if privateInfo.KeySignature == nil {
return Missing
}
config := config.Unpack(privateInfo.ElectionConfig)
voterListKey := keys.UnpackKey(config.VoterListServer.Key)
publicKey := PublicKey(privateInfo)
if sign.CheckSig(voterListKey, publicKey, privateInfo.KeySignature) {
return Valid
}
return Invalid
}