vendor

vendor/github.com/google/certificate-transparency-go/x509util/files.go

@@ -0,0 +1,73 @@
+// Copyright 2016 Google Inc. All Rights Reserved.
+//
+// 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 x509util
+
+import (
+	"encoding/pem"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"strings"
+)
+
+// ReadPossiblePEMFile loads data from a file which may be in DER format
+// or may be in PEM format (with the given blockname).
+func ReadPossiblePEMFile(filename, blockname string) ([][]byte, error) {
+	data, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return nil, fmt.Errorf("%s: failed to read data: %v", filename, err)
+	}
+	return dePEM(data, blockname), nil
+}
+
+// ReadPossiblePEMURL attempts to determine if the given target is a local file or a
+// URL, and return the file contents regardless. It also copes with either PEM or DER
+// format data.
+func ReadPossiblePEMURL(target, blockname string) ([][]byte, error) {
+	if !strings.HasPrefix(target, "http://") && !strings.HasPrefix(target, "https://") {
+		// Assume it's a filename
+		return ReadPossiblePEMFile(target, blockname)
+	}
+
+	rsp, err := http.Get(target)
+	if err != nil {
+		return nil, fmt.Errorf("failed to http.Get(%q): %v", target, err)
+	}
+	data, err := ioutil.ReadAll(rsp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("failed to ioutil.ReadAll(%q): %v", target, err)
+	}
+	return dePEM(data, blockname), nil
+}
+
+func dePEM(data []byte, blockname string) [][]byte {
+	var results [][]byte
+	if strings.Contains(string(data), "BEGIN "+blockname) {
+		rest := data
+		for {
+			var block *pem.Block
+			block, rest = pem.Decode(rest)
+			if block == nil {
+				break
+			}
+			if block.Type == blockname {
+				results = append(results, block.Bytes)
+			}
+		}
+	} else {
+		results = append(results, data)
+	}
+	return results
+}