verifysetup storage reader

2 files changed, 93 insertions, 0 deletions

diff --git a/verifysetup/core/crypt.go b/verifysetup/core/crypt.go
new file mode 100644
index 0000000..81130a3
--- /dev/null
+++ b/verifysetup/core/crypt.go
@@ -0,0 +1,18 @@
+package core
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"fmt"
+	"io"
+	"strings"
+)
+
+func CalculateBlockHash(block []byte) (string, error) {
+	hash := sha256.New()
+	if _, err := io.Copy(hash, bytes.NewReader(block)); err != nil {
+		return "", err
+	}
+	hashInBytes := hash.Sum(nil)[:32]
+	return strings.TrimSpace(fmt.Sprintf("%x", hashInBytes)), nil
+}
diff --git a/verifysetup/core/storage.go b/verifysetup/core/storage.go
new file mode 100644
index 0000000..831d637
--- /dev/null
+++ b/verifysetup/core/storage.go
@@ -0,0 +1,75 @@
+package core
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	verify "github.com/axtloss/fsverify/core"
+	bolt "go.etcd.io/bbolt"
+)
+
+var TotalReadBlocks = 0
+
+func ReadBlock(start int, end int, device *bytes.Reader) ([]byte, error) {
+	block := make([]byte, end-start)
+	_, err := device.Seek(int64(start), 0)
+	if err != nil {
+		return []byte{}, err
+	}
+	_, err = device.Read(block)
+	TotalReadBlocks = TotalReadBlocks + (end - start)
+	return block, err
+}
+
+func CreateNode(blockStart int, blockEnd int, block []byte, prevNode *verify.Node) (verify.Node, error) {
+	node := verify.Node{}
+	node.BlockStart = blockStart
+	node.BlockEnd = blockEnd
+	blockHash, err := CalculateBlockHash(block)
+	if err != nil {
+		return verify.Node{}, err
+	}
+	node.BlockSum = blockHash
+	var prevNodeHash string
+	if prevNode.PrevNodeSum != "" {
+		prevNodeHash, err = prevNode.GetHash()
+		if err != nil {
+			return verify.Node{}, err
+		}
+	} else {
+		prevNodeHash = "Entrypoint"
+	}
+	node.PrevNodeSum = prevNodeHash
+	return node, nil
+}
+
+func AddNode(node verify.Node, db *bolt.DB, dbPath string) error {
+	var err error
+	var deferDB bool
+	if db == nil {
+		db, err = bolt.Open(dbPath, 0777, nil)
+		if err != nil {
+			return err
+		}
+		deferDB = true
+	} else if db.IsReadOnly() {
+		return fmt.Errorf("Error: database is opened read only, unable to add nodes")
+	}
+	err = db.Update(func(tx *bolt.Tx) error {
+		nodes, err := tx.CreateBucketIfNotExists([]byte("Nodes"))
+		if err != nil {
+			return err
+		}
+		if buf, err := json.Marshal(node); err != nil {
+			return err
+		} else if err := nodes.Put([]byte(node.PrevNodeSum), buf); err != nil {
+			return err
+		}
+		return nil
+
+	})
+	if deferDB {
+		defer db.Close()
+	}
+	return err
+}