AUTH-910, AUTH-1049, AUTH-1068, AUTH-1056: Generate and store Access tokens with E2EE option, curl/cmd wrapper

vendor/github.com/coreos/pkg/timeutil/backoff.go

@@ -0,0 +1,15 @@
+package timeutil
+
+import (
+	"time"
+)
+
+func ExpBackoff(prev, max time.Duration) time.Duration {
+	if prev == 0 {
+		return time.Second
+	}
+	if prev > max/2 {
+		return max
+	}
+	return 2 * prev
+}