1 files changed, 81 insertions, 0 deletions
diff --git a/vendor/github.com/coreos/ignition/internal/exec/util/verification.go b/vendor/github.com/coreos/ignition/internal/exec/util/verification.go
new file mode 100644
index 00000000..77a74603
--- /dev/null
+++ b/vendor/github.com/coreos/ignition/internal/exec/util/verification.go
@@ -0,0 +1,81 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// 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 util
+
+import (
+	"crypto/sha512"
+	"encoding/hex"
+	"fmt"
+	"hash"
+
+	"github.com/coreos/ignition/config/types"
+)
+
+type ErrHashMismatch struct {
+	Calculated string
+	Expected   string
+}
+
+func (e ErrHashMismatch) Error() string {
+	return fmt.Sprintf("hash verification failed (calculated %s but expected %s)",
+		e.Calculated, e.Expected)
+}
+
+func AssertValid(verify types.Verification, data []byte) error {
+	if hash := verify.Hash; hash != nil {
+		hashFunc, hashSum, err := verify.HashParts()
+		if err != nil {
+			return err
+		}
+
+		var sum []byte
+		switch hashFunc {
+		case "sha512":
+			rawSum := sha512.Sum512(data)
+			sum = rawSum[:]
+		default:
+			return types.ErrHashUnrecognized
+		}
+
+		encodedSum := make([]byte, hex.EncodedLen(len(sum)))
+		hex.Encode(encodedSum, sum)
+		if string(encodedSum) != hashSum {
+			return ErrHashMismatch{
+				Calculated: string(encodedSum),
+				Expected:   hashSum,
+			}
+		}
+	}
+
+	return nil
+}
+
+func GetHasher(verify types.Verification) (hash.Hash, error) {
+	if verify.Hash == nil {
+		return nil, nil
+	}
+
+	function, _, err := verify.HashParts()
+	if err != nil {
+		return nil, err
+	}
+
+	switch function {
+	case "sha512":
+		return sha512.New(), nil
+	default:
+		return nil, types.ErrHashUnrecognized
+	}
+}