wip

peer/crypto.go

@@ -0,0 +1,32 @@
+package peer
+
+import (
+	"golang.org/x/crypto/nacl/box"
+	"golang.org/x/crypto/nacl/sign"
+)
+
+func encryptPacket(sharedKey, nonce, packet, out []byte) []byte {
+	out = box.SealAfterPrecomputation(out[:0], packet, (*[24]byte)(nonce), (*[32]byte)(sharedKey))
+	return append(out, nonce...)
+}
+
+func decryptPacket(sharedKey, packet, out []byte) (decrypted []byte, ok bool) {
+	cut := len(packet) - NONCE_SIZE
+	decrypted, ok = box.OpenAfterPrecomputation(out[:0], packet[:cut], (*[24]byte)(packet[cut:]), (*[32]byte)(sharedKey))
+	return decrypted, ok
+}
+
+// Signed packet should be encrypted with the encryptPacket function first.
+func signPacket(privKey, packet, out []byte) []byte {
+	return sign.Sign(out[:0], packet, (*[64]byte)(privKey))
+}
+
+func openPacket(pubKey, packet, out []byte) (encPacket []byte, ok bool) {
+	return sign.Open(out[:0], packet, (*[32]byte)(pubKey))
+}
+
+func computeSharedKey(peerPubKey, privKey []byte) []byte {
+	shared := [32]byte{}
+	box.Precompute(&shared, (*[32]byte)(peerPubKey), (*[32]byte)(privKey))
+	return shared[:]
+}