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// Copyright 2014 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
// +build none
// Contains a simple whisper peer setup and self messaging to allow playing
// around with the protocol and API without a fancy client implementation.
package main
import (
"fmt"
"log"
"os"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/p2p"
"github.com/ethereum/go-ethereum/p2p/nat"
"github.com/ethereum/go-ethereum/whisper"
)
func main() {
logger.AddLogSystem(logger.NewStdLogSystem(os.Stdout, log.LstdFlags, logger.InfoLevel))
// Generate the peer identity
key, err := crypto.GenerateKey()
if err != nil {
fmt.Printf("Failed to generate peer key: %v.\n", err)
os.Exit(-1)
}
name := common.MakeName("whisper-go", "1.0")
shh := whisper.New()
// Create an Ethereum peer to communicate through
server := p2p.Server{
PrivateKey: key,
MaxPeers: 10,
Name: name,
Protocols: []p2p.Protocol{shh.Protocol()},
ListenAddr: ":30300",
NAT: nat.Any(),
}
fmt.Println("Starting Ethereum peer...")
if err := server.Start(); err != nil {
fmt.Printf("Failed to start Ethereum peer: %v.\n", err)
os.Exit(1)
}
// Send a message to self to check that something works
payload := fmt.Sprintf("Hello world, this is %v. In case you're wondering, the time is %v", name, time.Now())
if err := selfSend(shh, []byte(payload)); err != nil {
fmt.Printf("Failed to self message: %v.\n", err)
os.Exit(-1)
}
}
// 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
}
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