package whisper import ( "crypto/ecdsa" "time" "github.com/ethereum/go-ethereum/crypto" ) type Message struct { Flags byte Signature []byte Payload []byte Sent uint64 } 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 } } if opts.Ttl == 0 { opts.Ttl = DefaultTtl } envelope := NewEnvelope(opts.Ttl, opts.Topics, self) envelope.Seal(pow) return envelope, nil }