noise: store clamped key instead of raw key

1 files changed, 6 insertions, 4 deletions

diff --git a/noise-helpers.go b/noise-helpers.go
index 1b2746c..af11f09 100644
--- a/noise-helpers.go
+++ b/noise-helpers.go
@@ -78,12 +78,14 @@ func setZero(arr []byte) {
 	}
 }
 
+func (sk *NoisePrivateKey) clamp() {
+	sk[0] &= 248
+	sk[31] = (sk[31] & 127) | 64
+}
+
 func newPrivateKey() (sk NoisePrivateKey, err error) {
-	// clamping: https://cr.yp.to/ecdh.html
 	_, err = rand.Read(sk[:])
-	sk[0] &= 248
-	sk[31] &= 127
-	sk[31] |= 64
+	sk.clamp()
 	return
 }