diff --git a/cmd/kubeadm/app/util/pkiutil/testing/testdata/21.rsa.key b/cmd/kubeadm/app/util/pkiutil/testing/testdata/21.rsa.key
new file mode 100644
index 00000000000..9f9b53a665c
--- /dev/null
+++ b/cmd/kubeadm/app/util/pkiutil/testing/testdata/21.rsa.key
@@ -0,0 +1,27 @@
+-----BEGIN RSA PRIVATE KEY-----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+-----END RSA PRIVATE KEY-----
diff --git a/cmd/kubeadm/app/util/pkiutil/testing/testdata/22.rsa.key b/cmd/kubeadm/app/util/pkiutil/testing/testdata/22.rsa.key
new file mode 100644
index 00000000000..d230c09751c
--- /dev/null
+++ b/cmd/kubeadm/app/util/pkiutil/testing/testdata/22.rsa.key
@@ -0,0 +1,27 @@
+-----BEGIN RSA PRIVATE KEY-----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+-----END RSA PRIVATE KEY-----
diff --git a/cmd/kubeadm/app/util/pkiutil/testing/testdata/23.rsa.key b/cmd/kubeadm/app/util/pkiutil/testing/testdata/23.rsa.key
new file mode 100644
index 00000000000..82b72268d3c
--- /dev/null
+++ b/cmd/kubeadm/app/util/pkiutil/testing/testdata/23.rsa.key
@@ -0,0 +1,27 @@
+-----BEGIN RSA PRIVATE KEY-----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+-----END RSA PRIVATE KEY-----