1 files changed, 74 insertions, 0 deletions
diff --git a/whisper/message.go b/whisper/message.go
new file mode 100644
index 000000000..db0110b4a
--- /dev/null
+++ b/whisper/message.go
@@ -0,0 +1,74 @@
+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
+}