// 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
}
// Watch installs a new message handler to run in case a matching packet arrives
// from the whisper network.
func (self *Whisper) Watch(to, from string, topics [][]string, fn func(WhisperMessage)) int {
// Decode the topic strings
topicsDecoded := make([][][]byte, len(topics))
for i, condition := range topics {
topicsDecoded[i] = make([][]byte, len(condition))
for j, topic := range condition {
topicsDecoded[i][j] = common.FromHex(topic)
}
}
// Assemble and inject the filter into the whisper client
filter := whisper.Filter{
To: crypto.ToECDSAPub(common.FromHex(to)),
From: crypto.ToECDSAPub(common.FromHex(from)),
Topics: whisper.NewFilterTopics(topicsDecoded...),
}
filter.Fn = func(message *whisper.Message) {
fn(NewWhisperMessage(message))
}
return self.Whisper.Watch(filter)
}
// importPublicKey unmarshals 512 bit public keys.
func importPublicKey(pubKey []byte) (*ecies.PublicKey, error) {
var pubKey65 []byte
switch len(pubKey) {
case 64:
// add 'uncompressed key' flag
pubKey65 = append([]byte{0x04}, pubKey...)
case 65:
pubKey65 = pubKey
default:
return nil, fmt.Errorf("invalid public key length %v (expect 64/65)", len(pubKey))
}
// TODO: fewer pointless conversions
return ecies.ImportECDSAPublic(crypto.ToECDSAPub(pubKey65)), nil
}
// HasIdentity checks if the the whisper node is configured with the private key
// of the specified public pair.
func (self *Whisper) HasIdentity(key string) bool {
return self.Whisper.HasIdentity(crypto.ToECDSAPub(common.FromHex(key)))
}