m/node/kubernetes/pki: refactor out CA functionality
This factors out all non-k8s-specific CA functionality from
metropolis/node/kubernetes/pki into metropolis/pkg/pki.
This will allow us to re-use the same PKI-in-CA system to issue
certificates for the Metropolis cluster and nodes.
We also drive-by change some Kubernetes/PKI interactions to make things
cleaner. Notably, this implements Certificate.Mount to return a
fileargs.FileArgs containing all the files neede to use this
Certificate.
Test Plan: covered by current e2e tests. An etcd harness to test this independently would be nice, though.
X-Origin-Diff: phab/D709
GitOrigin-RevId: bdc9ff215b94c9192f65c6da8935fe2818fd14ad
diff --git a/metropolis/pkg/pki/x509.go b/metropolis/pkg/pki/x509.go
new file mode 100644
index 0000000..d2affe8
--- /dev/null
+++ b/metropolis/pkg/pki/x509.go
@@ -0,0 +1,57 @@
+// Copyright 2020 The Monogon Project Authors.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package pki
+
+import (
+ "crypto"
+ "crypto/sha1"
+ "crypto/x509"
+ "crypto/x509/pkix"
+ "encoding/asn1"
+ "time"
+)
+
+var (
+ // From RFC 5280 Section 4.1.2.5
+ unknownNotAfter = time.Unix(253402300799, 0)
+)
+
+// Workaround for https://github.com/golang/go/issues/26676 in Go's crypto/x509. Specifically Go
+// violates Section 4.2.1.2 of RFC 5280 without this.
+// Fixed for 1.15 in https://go-review.googlesource.com/c/go/+/227098/.
+//
+// Taken from https://github.com/FiloSottile/mkcert/blob/master/cert.go#L295 written by one of Go's
+// crypto engineers
+//
+// TODO(lorenz): remove this once we migrate to Go 1.15.
+func calculateSKID(pubKey crypto.PublicKey) ([]byte, error) {
+ spkiASN1, err := x509.MarshalPKIXPublicKey(pubKey)
+ if err != nil {
+ return nil, err
+ }
+
+ var spki struct {
+ Algorithm pkix.AlgorithmIdentifier
+ SubjectPublicKey asn1.BitString
+ }
+ _, err = asn1.Unmarshal(spkiASN1, &spki)
+ if err != nil {
+ return nil, err
+ }
+ skid := sha1.Sum(spki.SubjectPublicKey.Bytes)
+ return skid[:], nil
+}