cns:     []string{testFileCN, testDirCN},
		},
	}

	// Save old settings so we can restore before the test ends.
	origCertFiles, origCertDirectories := certFiles, certDirectories
	origFile, origDir := os.Getenv(certFileEnv), os.Getenv(certDirEnv)
	defer func() {
		certFiles = origCertFiles
		certDirectories = origCertDirectories
		os.Setenv(certFileEnv, origFile)
		os.Setenv(certDirEnv, origDir)
	}()