vendor files

vendor/k8s.io/kubernetes/pkg/controller/bootstrap/jws.go

@@ -0,0 +1,73 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+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 bootstrap
+
+import (
+	"fmt"
+	"strings"
+
+	jose "github.com/square/go-jose"
+)
+
+// computeDetachedSig takes content and token details and computes a detached
+// JWS signature.  This is described in Appendix F of RFC 7515.  Basically, this
+// is a regular JWS with the content part of the signature elided.
+func computeDetachedSig(content, tokenID, tokenSecret string) (string, error) {
+	jwk := &jose.JsonWebKey{
+		Key:   []byte(tokenSecret),
+		KeyID: tokenID,
+	}
+
+	signer, err := jose.NewSigner(jose.HS256, jwk)
+	if err != nil {
+		return "", fmt.Errorf("can't make a HS256 signer from the given token: %v", err)
+	}
+
+	jws, err := signer.Sign([]byte(content))
+	if err != nil {
+		return "", fmt.Errorf("can't HS256-sign the given token: %v", err)
+	}
+
+	fullSig, err := jws.CompactSerialize()
+	if err != nil {
+		return "", fmt.Errorf("can't serialize the given token: %v", err)
+	}
+	return stripContent(fullSig)
+}
+
+// stripContent will remove the content part of a compact JWS
+//
+// The `go-jose` library doesn't support generating signatures with "detatched"
+// content. To make up for this we take the full compact signature, break it
+// apart and put it back together without the content section.
+func stripContent(fullSig string) (string, error) {
+	parts := strings.Split(fullSig, ".")
+	if len(parts) != 3 {
+		return "", fmt.Errorf("compact JWS format must have three parts")
+	}
+
+	return parts[0] + ".." + parts[2], nil
+}
+
+// DetachedTokenIsValid checks whether a given detached JWS-encoded token matches JWS output of the given content and token
+func DetachedTokenIsValid(detachedToken, content, tokenID, tokenSecret string) bool {
+	newToken, err := computeDetachedSig(content, tokenID, tokenSecret)
+	if err != nil {
+		return false
+	}
+	return detachedToken == newToken
+}