crypto/rand: zero length reads shouldn't crash on Windows.
R=golang-dev, dave
CC=golang-dev
https://golang.org/cl/6496099
diff --git a/src/pkg/crypto/rand/rand_test.go b/src/pkg/crypto/rand/rand_test.go
index da091ba..394fd45 100644
--- a/src/pkg/crypto/rand/rand_test.go
+++ b/src/pkg/crypto/rand/rand_test.go
@@ -30,3 +30,14 @@
t.Fatalf("Compressed %d -> %d", len(b), z.Len())
}
}
+
+func TestReadEmpty(t *testing.T) {
+ n, err := Reader.Read(make([]byte, 0))
+ if n != 0 || err != nil {
+ t.Fatalf("Read(make([]byte, 0)) = %d, %v", n, err)
+ }
+ n, err = Reader.Read(nil)
+ if n != 0 || err != nil {
+ t.Fatalf("Read(make(nil) = %d, %v", n, err)
+ }
+}
diff --git a/src/pkg/crypto/rand/rand_windows.go b/src/pkg/crypto/rand/rand_windows.go
index 2b2bd4b..82b39b6 100644
--- a/src/pkg/crypto/rand/rand_windows.go
+++ b/src/pkg/crypto/rand/rand_windows.go
@@ -35,6 +35,10 @@
}
}
r.mu.Unlock()
+
+ if len(b) == 0 {
+ return 0, nil
+ }
err = syscall.CryptGenRandom(r.prov, uint32(len(b)), &b[0])
if err != nil {
return 0, os.NewSyscallError("CryptGenRandom", err)
