Align with go library layout

keypair.go

@@ -0,0 +1,44 @@
+package main
+
+import (
+	"crypto/cipher"
+	"sync"
+	"time"
+)
+
+/* Due to limitations in Go and /x/crypto there is currently
+ * no way to ensure that key material is securely ereased in memory.
+ *
+ * Since this may harm the forward secrecy property,
+ * we plan to resolve this issue; whenever Go allows us to do so.
+ */
+
+type KeyPair struct {
+	send         cipher.AEAD
+	receive      cipher.AEAD
+	replayFilter ReplayFilter
+	sendNonce    uint64
+	isInitiator  bool
+	created      time.Time
+	localIndex   uint32
+	remoteIndex  uint32
+}
+
+type KeyPairs struct {
+	mutex    sync.RWMutex
+	current  *KeyPair
+	previous *KeyPair
+	next     *KeyPair // not yet "confirmed by transport"
+}
+
+func (kp *KeyPairs) Current() *KeyPair {
+	kp.mutex.RLock()
+	defer kp.mutex.RUnlock()
+	return kp.current
+}
+
+func (device *Device) DeleteKeyPair(key *KeyPair) {
+	if key != nil {
+		device.indices.Delete(key.localIndex)
+	}
+}