// Post injects a message into the whisper network for distribution.
func (self *Whisper) Post(payload string, to, from string, topics []string, priority, ttl uint32) error {
// Decode the topic strings
topicsDecoded := make([][]byte, len(topics))
for i, topic := range topics {
topicsDecoded[i] = common.FromHex(topic)
}
// Construct the whisper message and transmission options
message := whisper.NewMessage(common.FromHex(payload))
options := whisper.Options{
To: crypto.ToECDSAPub(common.FromHex(to)),
TTL: time.Duration(ttl) * time.Second,
Topics: whisper.NewTopics(topicsDecoded...),
}
if len(from) != 0 {
if key := self.Whisper.GetIdentity(crypto.ToECDSAPub(common.FromHex(from))); key != nil {
options.From = key
} else {
return fmt.Errorf("unknown identity to send from: %s", from)
}
}
// Wrap and send the message
pow := time.Duration(priority) * time.Millisecond
envelope, err := message.Wrap(pow, options)
if err != nil {
return err
}
if err := self.Whisper.Send(envelope); err != nil {
return err
}
return nil
}
// SendSelf wraps a payload into a Whisper envelope and forwards it to itself.
func selfSend(shh *whisper.Whisper, payload []byte) error {
ok := make(chan struct{})
// Start watching for self messages, output any arrivals
id := shh.NewIdentity()
shh.Watch(whisper.Filter{
To: &id.PublicKey,
Fn: func(msg *whisper.Message) {
fmt.Printf("Message received: %s, signed with 0x%x.\n", string(msg.Payload), msg.Signature)
close(ok)
},
})
// Wrap the payload and encrypt it
msg := whisper.NewMessage(payload)
envelope, err := msg.Wrap(whisper.DefaultPoW, whisper.Options{
From: id,
To: &id.PublicKey,
TTL: whisper.DefaultTTL,
})
if err != nil {
return fmt.Errorf("failed to seal message: %v", err)
}
// Dump the message into the system and wait for it to pop back out
if err := shh.Send(envelope); err != nil {
return fmt.Errorf("failed to send self-message: %v", err)
}
select {
case <-ok:
case <-time.After(time.Second):
return fmt.Errorf("failed to receive message in time")
}
return nil
}