fw: Add checksum to partition table

Refuse to boot if blake2s digest over the partition table does not match
digest stored on flash

hw/application_fpga/tools/partition_table/partition_table.go

@@ -7,29 +7,40 @@ import (
 	"fmt"
 	"io"
 	"os"
+
+	"golang.org/x/crypto/blake2s"
 )
 
+type PreLoadedAppData struct {
+	Size      uint32
+	Digest    [32]uint8
+	Signature [64]uint8
+}
+
+type Auth struct {
+	Nonce      [16]uint8
+	AuthDigest [16]uint8
+}
+
+type AppStorage struct {
+	Status uint8
+	Auth   Auth
+}
+
 type PartTable struct {
-	Header struct {
-		Version uint8
-	}
-	PreLoadedAppData [2]struct {
-		Size      uint32
-		Digest    [32]uint8
-		Signature [64]uint8
-	}
-	AppStorage [4]struct {
-		Status uint8
-		Auth   struct {
-			Nonce      [16]uint8
-			AuthDigest [16]uint8
-		}
-	}
+	Version          uint8
+	PreLoadedAppData [2]PreLoadedAppData
+	AppStorage       [4]AppStorage
+}
+
+type PartTableStorage struct {
+	PartTable PartTable
+	Digest    [16]uint8
 }
 
 type Flash struct {
 	Bitstream             [0x20000]uint8
-	PartitionTable        PartTable
+	PartitionTableStorage PartTableStorage
 	PartitionTablePadding [64*1024 - 365]uint8
 	PreLoadedApp0         [0x20000]uint8
 	PreLoadedApp1         [0x20000]uint8
@@ -37,6 +48,24 @@ type Flash struct {
 	EndPadding            [0x10000]uint8
 }
 
+func readPartTableStorage(filename string) PartTableStorage {
+	var storage PartTableStorage
+
+	tblFile, err := os.Open(filename)
+	if err != nil {
+		panic(err)
+	}
+
+	if err := binary.Read(tblFile, binary.LittleEndian, &storage); err != nil {
+		fmt.Println("binary.Read failed:", err)
+	}
+
+	tblStructLen, _ := tblFile.Seek(0, io.SeekCurrent)
+	fmt.Fprintf(os.Stderr, "INFO: Go partition table struct is %d byte long\n", tblStructLen)
+
+	return storage
+}
+
 func readPartTable(filename string) PartTable {
 	var tbl PartTable
 
@@ -73,6 +102,14 @@ func readFlashDump(filename string) Flash {
 	return flash
 }
 
+func printPartTableStorageJson(storage PartTableStorage) {
+	json, err := json.MarshalIndent(storage, "", "  ")
+	if err != nil {
+		panic(err)
+	}
+	fmt.Printf("%s\n", string(json))
+}
+
 func printPartTableJson(tbl PartTable) {
 	partTableJSON, err := json.MarshalIndent(tbl, "", "  ")
 	if err != nil {
@@ -81,11 +118,11 @@ func printPartTableJson(tbl PartTable) {
 	fmt.Printf("%s\n", string(partTableJSON))
 }
 
-func printPartTableCondensed(tbl PartTable) {
+func printPartTableCondensed(storage PartTableStorage) {
 	fmt.Printf("Header\n")
-	fmt.Printf("  Version          : %d\n", tbl.Header.Version)
+	fmt.Printf("  Version          : %d\n", storage.PartTable.Version)
 
-	for i, appData := range tbl.PreLoadedAppData {
+	for i, appData := range storage.PartTable.PreLoadedAppData {
 		fmt.Printf("Preloaded App %d\n", i)
 		fmt.Printf("  Size             : %d\n", appData.Size)
 		fmt.Printf("  Digest           : %x\n", appData.Digest[:16])
@@ -97,6 +134,49 @@ func printPartTableCondensed(tbl PartTable) {
 	}
 }
 
+func printPartTableStorageCondensed(storage PartTableStorage) {
+}
+
+func calculateStorageDigest(data []byte) []byte {
+	key := [16]byte{}
+	hash, err := blake2s.New128(key[:])
+	if err != nil {
+		panic(err)
+	}
+	hash.Write(data)
+	digest := hash.Sum([]byte{})
+
+	return digest
+}
+
+func generatePartTableStorage(filename string) {
+	storage := PartTableStorage{
+		PartTable: PartTable{
+			Version:          1,
+			PreLoadedAppData: [2]PreLoadedAppData{},
+			AppStorage:       [4]AppStorage{},
+		},
+	}
+
+	buf := make([]byte, 4096, 4096)
+	len, err := binary.Encode(buf, binary.LittleEndian, storage.PartTable)
+	if err != nil {
+		panic(err)
+	}
+
+	digest := calculateStorageDigest(buf[:len])
+	copy(storage.Digest[:], digest)
+
+	storageFile, err := os.Create(filename)
+	if err != nil {
+		panic(err)
+	}
+
+	if err := binary.Write(storageFile, binary.LittleEndian, storage); err != nil {
+		fmt.Println("binary.Write failed:", err)
+	}
+}
+
 func main() {
 	filename := ""
 	json := false
@@ -112,17 +192,20 @@ func main() {
 		os.Exit(1)
 	}
 
-	var tbl PartTable
+	generatePartTableStorage(filename)
+	return
 
-	if flash {
-		tbl = readFlashDump(filename).PartitionTable
-	} else {
-		tbl = readPartTable(filename)
-	}
+	// var tbl PartTable
 
-	if json {
-		printPartTableJson(tbl)
-	} else {
-		printPartTableCondensed(tbl)
-	}
+	// if flash {
+	// 	tbl = readFlashDump(filename).PartitionTable
+	// } else {
+	// 	tbl = readPartTable(filename)
+	// }
+
+	// if json {
+	// 	printPartTableJson(tbl)
+	// } else {
+	// 	printPartTableCondensed(tbl)
+	// }
 }