func (m *Bmail) generateAck(s ServerOps) (ack obj.Object, powData *pow.Data, err error) {
// If this is a broadcast message, no ack is expected.
if m.To == "*****@*****.**" {
return nil, nil, errors.New("No acks on broadcast messages.")
}
// if no object form exists, attempt to generate that.
if m.object == nil {
obj, _, err := m.GenerateObject(s)
if obj == nil {
smtpLog.Debug("trySend: could not generate message. Pubkey request sent? ", err == nil)
if err == nil {
return nil, nil, errors.New("Private key missing.")
}
return nil, nil, err
}
}
// Get our private key.
fromAddr, err := emailToBM(m.From)
if err != nil {
return nil, nil, err
}
from := s.GetPrivateID(fromAddr)
addr := from.ToPublic().Address
// TODO make a separate function in bmutil that does this.
var signingKey, encKey wire.PubKey
var destination wire.RipeHash
sk := from.SigningKey.PubKey().SerializeUncompressed()[1:]
ek := from.EncryptionKey.PubKey().SerializeUncompressed()[1:]
copy(signingKey[:], sk)
copy(encKey[:], ek)
copy(destination[:], addr.Ripe[:])
// Add the message, which is a random number.
buf := new(bytes.Buffer)
num := rand.Int31()
err = binary.Write(buf, binary.LittleEndian, num)
if err != nil {
return nil, nil, err
}
header := m.object.Header()
msgAck := wire.NewMsgObject(
wire.NewObjectHeader(0,
header.Expiration(),
wire.ObjectTypeMsg,
obj.MessageVersion,
addr.Stream,
), buf.Bytes())
// Encode it and save.
m.Ack = wire.Encode(msgAck)
return msgAck, &from.Data, nil
}
// Serialize encodes the message in a protobuf format.
func (m *Bmail) Serialize() ([]byte, error) {
expr := m.Expiration.Format(dateFormat)
var imapData *serialize.ImapData
if m.ImapData != nil {
t := m.ImapData.TimeReceived.Format(dateFormat)
imapData = &serialize.ImapData{
TimeReceived: t,
Flags: int32(m.ImapData.Flags),
}
}
var object []byte
if m.object != nil {
object = wire.Encode(m.object)
}
var state *serialize.MessageState
if m.state != nil {
lastsend := m.state.LastSend.Format(dateFormat)
state = &serialize.MessageState{
SendTries: m.state.SendTries,
AckExpected: m.state.AckExpected,
AckReceived: m.state.AckReceived,
PubkeyRequested: m.state.PubkeyRequestOutstanding,
LastSend: lastsend,
Received: m.state.Received,
}
}
smtpLog.Trace("Serializing Bitmessage from " + m.From + " to " + m.To)
encode := &serialize.Message{
From: m.From,
To: m.To,
OfChannel: m.OfChannel,
Expiration: expr,
Ack: m.Ack,
ImapData: imapData,
Encoding: m.Content.ToProtobuf(),
Object: object,
State: state,
}
data, err := proto.Marshal(encode)
if err != nil {
return nil, err
}
return data, nil
}
// trySend takes a Bitmessage and does whatever needs to be done to it
// next in order to send it into the network. There are some steps in this
// process that take a bit of time, so they can't all be handled sequentially
// by one function. If we don't have the recipient's private key yet, we
// can't send the message and we have to send a pubkey request to him instead.
// On the other hand, messages might come in for which we already have the
// public key and then we can go on to the next step right away.
//
// The next step is proof-of-work, and that also takes time.
func (u *User) trySend(bmsg *Bmail) error {
outbox := u.boxes[OutboxFolderName]
// First we attempt to generate the wire.Object form of the message.
// If we can't, then it is possible that we don't have the recipient's
// pubkey. That is not an error state. If no object and no error is
// returned, this is what has happened. If there is no object, then we
// can't proceed futher so trySend completes.
object, powData, err := bmsg.GenerateObject(u.server)
if object == nil {
smtpLog.Debug("trySend: could not generate message. Pubkey request sent? ", err == nil)
if err == nil {
bmsg.state.PubkeyRequestOutstanding = true
err := outbox.saveBitmessage(bmsg)
if err != nil {
return err
}
return nil
}
return err
}
bmsg.state.PubkeyRequestOutstanding = false
// sendPow takes a message in wire format with all required information
// to send it over the network other than having proof-of-work run on it.
// It generates the correct parameters for running the proof-of-work and
// sends it to the proof-of-work queue with a function provided by the
// user that says what to do with the completed message when the
// proof-of-work is done.
sendPow := func(object obj.Object, powData *pow.Data, done func([]byte)) {
encoded := wire.Encode(object)
q := encoded[8:] // exclude the nonce
target := pow.CalculateTarget(uint64(len(q)),
uint64(object.Header().Expiration().Sub(time.Now()).Seconds()), *powData)
// Attempt to run pow on the message.
u.server.RunPow(target, q, func(n pow.Nonce) {
// Put the nonce bytes into the encoded form of the message.
q = append(n.Bytes(), q...)
done(q)
})
}
// sendPreparedMessage is used after we have looked up private keys and
// generated an ack message, if applicable.
sendPreparedMessage := func() error {
err := outbox.saveBitmessage(bmsg)
if err != nil {
return err
}
// Put the prepared object in the pow queue and send it off
// through the network.
sendPow(object, powData, func(completed []byte) {
err := func() error {
// Save Bitmessage in outbox folder.
err := u.boxes[OutboxFolderName].saveBitmessage(bmsg)
if err != nil {
return err
}
u.server.Send(completed)
// Select new box for the message.
var newBoxName string
if bmsg.state.AckExpected {
newBoxName = LimboFolderName
} else {
newBoxName = SentFolderName
}
bmsg.state.SendTries++
bmsg.state.LastSend = time.Now()
return u.Move(bmsg, OutboxFolderName, newBoxName)
}()
// We can't return the error any further because this function
// isn't even run until long after trySend completes!
if err != nil {
smtpLog.Error("trySend: ", err)
}
})
return nil
}
// We may desire to receive an ack with this message, which has not yet
// been created. In that case, we need to do proof-of-work on the ack just
// as on the entire message.
if bmsg.Ack != nil && bmsg.state.AckExpected {
ack, powData, err := bmsg.generateAck(u.server)
if err != nil {
return err
}
err = outbox.saveBitmessage(bmsg)
if err != nil {
return err
}
sendPow(ack, powData, func(completed []byte) {
err := func() error {
// Add the ack to the message.
bmsg.Ack = completed
return sendPreparedMessage()
}
// Once again, we can't return the error any further because
// trySend is over by the time this function is run.
if err != nil {
smtpLog.Error("trySend: ", err)
}
})
} else {
return sendPreparedMessage()
}
return nil
}