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package whisper
import (
"crypto/ecdsa"
"time"
"github.com/ethereum/go-ethereum/crypto"
)
type Message struct {
Flags byte
Signature []byte
Payload []byte
}
func NewMessage(payload []byte) *Message {
return &Message{Flags: 0, Payload: payload}
}
func (self *Message) hash() []byte {
return crypto.Sha3(append([]byte{self.Flags}, self.Payload...))
}
func (self *Message) sign(key *ecdsa.PrivateKey) (err error) {
self.Flags = 1
self.Signature, err = crypto.Sign(self.hash(), key)
return
}
func (self *Message) Recover() *ecdsa.PublicKey {
defer func() { recover() }() // in case of invalid sig
return crypto.SigToPub(self.hash(), self.Signature)
}
func (self *Message) Encrypt(to *ecdsa.PublicKey) (err error) {
self.Payload, err = crypto.Encrypt(to, self.Payload)
if err != nil {
return err
}
return nil
}
func (self *Message) Bytes() []byte {
return append([]byte{self.Flags}, append(self.Signature, self.Payload...)...)
}
type Opts struct {
From *ecdsa.PrivateKey
To *ecdsa.PublicKey
Ttl time.Duration
Topics [][]byte
}
func (self *Message) Seal(pow time.Duration, opts Opts) (*Envelope, error) {
if opts.From != nil {
err := self.sign(opts.From)
if err != nil {
return nil, err
}
}
if opts.To != nil {
err := self.Encrypt(opts.To)
if err != nil {
return nil, err
}
}
envelope := NewEnvelope(DefaultTtl, opts.Topics, self)
envelope.Seal(pow)
return envelope, nil
}
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