* [PATCH] device: in setZero, keep arr alive after being written to
@ 2019-07-31 13:36 nsajko
2019-08-27 22:54 ` Jason A. Donenfeld
0 siblings, 1 reply; 3+ messages in thread
From: nsajko @ 2019-07-31 13:36 UTC (permalink / raw)
To: wireguard
[-- Attachment #1.1: Type: text/plain, Size: 979 bytes --]
This is to prevent dead store elimination.
See the discussion at
golang/go#33325 .
diff --git a/device/noise-helpers.go b/device/noise-helpers.go
index f5e4b4b..29430da 100644
--- a/device/noise-helpers.go
+++ b/device/noise-helpers.go
@@ -10,6 +10,7 @@ import (
"crypto/rand"
"crypto/subtle"
"hash"
+ "runtime"
"golang.org/x/crypto/blake2s"
"golang.org/x/crypto/curve25519"
@@ -69,11 +70,16 @@ func isZero(val []byte) bool {
return acc == 1
}
-/* This function is not used as pervasively as it should because this is mostly impossible in Go at the moment */
+/* This function is not used as pervasively as it should */
func setZero(arr []byte) {
for i := range arr {
arr[i] = 0
}
+
+ // This should keep arr's backing array live and thus prevent dead store
+ // elimination, according to discussion at
+ // https://github.com/golang/go/issues/33325 .
+ runtime.KeepAlive(arr)
}
func (sk *NoisePrivateKey) clamp() {
[-- Attachment #2: Type: text/plain, Size: 148 bytes --]
_______________________________________________
WireGuard mailing list
WireGuard@lists.zx2c4.com
https://lists.zx2c4.com/mailman/listinfo/wireguard
^ permalink raw reply related [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-08-28 2:25 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-07-31 13:36 [PATCH] device: in setZero, keep arr alive after being written to nsajko
2019-08-27 22:54 ` Jason A. Donenfeld
2019-08-27 23:02 ` Neven Sajko
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).