3 files changed, 52 insertions, 0 deletions
diff --git a/src/crypto/boring/boring.go b/src/crypto/boring/boring.go
new file mode 100644
index 00000000000..19e2a0876f7
--- /dev/null
+++ b/src/crypto/boring/boring.go
@@ -0,0 +1,19 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package boring exposes functions that are only available when building with
+// Go+BoringCrypto. This package is available on all targets as long as the
+// Go+BoringCrypto toolchain is used. Use the Enabled function to determine
+// whether the BoringCrypto core is actually in use.
+//
+// Any time the Go+BoringCrypto toolchain is used, the "boringcrypto" build tag
+// is satisfied, so that applications can tag files that use this package.
+package boring
+
+import "crypto/internal/boring"
+
+// Enabled reports whether BoringCrypto handles supported crypto operations.
+func Enabled() bool {
+	return boring.Enabled
+}
diff --git a/src/crypto/boring/boring_test.go b/src/crypto/boring/boring_test.go
new file mode 100644
index 00000000000..ace50de0c2b
--- /dev/null
+++ b/src/crypto/boring/boring_test.go
@@ -0,0 +1,20 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package boring_test
+
+import (
+	"crypto/boring"
+	"runtime"
+	"testing"
+)
+
+func TestEnabled(t *testing.T) {
+	supportedPlatform := runtime.GOOS == "linux" && runtime.GOARCH == "amd64"
+	if supportedPlatform && !boring.Enabled() {
+		t.Error("Enabled returned false on a supported platform")
+	} else if !supportedPlatform && boring.Enabled() {
+		t.Error("Enabled returned true on an unsupported platform")
+	}
+}
diff --git a/src/crypto/boring/notboring_test.go b/src/crypto/boring/notboring_test.go
new file mode 100644
index 00000000000..385a384dd75
--- /dev/null
+++ b/src/crypto/boring/notboring_test.go
@@ -0,0 +1,13 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !boringcrypto
+
+package boring_test
+
+import "testing"
+
+func TestNotBoring(t *testing.T) {
+	t.Error("a file tagged !boringcrypto should not build under Go+BoringCrypto")
+}