use chunk processing functions from ledger_go

Author: chcmedeiros

app.go

@@ -209,12 +209,12 @@ func (ledger *LedgerFilecoin) sign(bip44Path []uint32, transaction []byte, curve
 		return nil, err
 	}
 
-	chunks, err := prepareChunks(pathBytes, transaction)
+	chunks, err := ledger_go.PrepareChunks(pathBytes, transaction)
 	if err != nil {
 		return nil, err
 	}
 
-	return ledger.processChunks(chunks, INSSign)
+	return ledger_go.ProcessChunks(ledger.api, chunks, CLA, INSSign, apduP2Default, handleExchangeError)
 }
 
 // SignPersonalMessageFVM signs a personal message for FVM (Filecoin Virtual Machine)
@@ -241,12 +241,12 @@ func (ledger *LedgerFilecoin) signPersonalMessage(bip44Path []uint32, message []
 	binary.BigEndian.PutUint32(fullMessage[0:messageLengthPrefixSize], messageLen)
 	copy(fullMessage[messageLengthPrefixSize:], message)
 
-	chunks, err := prepareChunks(pathBytes, fullMessage)
+	chunks, err := ledger_go.PrepareChunks(pathBytes, fullMessage)
 	if err != nil {
 		return nil, err
 	}
 
-	return ledger.processChunks(chunks, INSSignPersonalMsg)
+	return ledger_go.ProcessChunks(ledger.api, chunks, CLA, INSSignPersonalMsg, apduP2Default, handleExchangeError)
 }
 
 // retrieveAddressPubKey returns the pubkey and address
@@ -274,12 +274,12 @@ func (ledger *LedgerFilecoin) signRawBytes(bip44Path []uint32, message []byte) (
 	copy(fullMessage, varintLen)
 	copy(fullMessage[len(varintLen):], message)
 
-	chunks, err := prepareChunks(pathBytes, fullMessage)
+	chunks, err := ledger_go.PrepareChunks(pathBytes, fullMessage)
 	if err != nil {
 		return nil, err
 	}
 
-	return ledger.processChunks(chunks, INSSignRawBytes)
+	return ledger_go.ProcessChunks(ledger.api, chunks, CLA, INSSignRawBytes, apduP2Default, handleExchangeError)
 }
 
 func parseSignatureResponse(signatureBytes []byte) (*SignatureAnswer, error) {
@@ -295,34 +295,7 @@ func parseSignatureResponse(signatureBytes []byte) (*SignatureAnswer, error) {
 	}, nil
 }
 
-func (ledger *LedgerFilecoin) processChunks(chunks [][]byte, instruction byte) ([]byte, error) {
-	var finalResponse []byte
-
-	for chunkIndex, chunk := range chunks {
-		payloadLen := byte(len(chunk))
-		payloadDesc := PayloadChunkAdd
-
-		if chunkIndex == 0 {
-			payloadDesc = PayloadChunkInit
-		} else if chunkIndex == len(chunks)-1 {
-			payloadDesc = PayloadChunkLast
-		}
-
-		header := []byte{CLA, instruction, byte(payloadDesc), apduP2Default, payloadLen}
-		message := append(header, chunk...)
-
-		response, err := ledger.api.Exchange(message)
-		if err != nil {
-			return nil, handleExchangeError(err, response)
-		}
-
-		finalResponse = response
-	}
-
-	return finalResponse, nil
-}
-
-func handleExchangeError(err error, response []byte) error {
+func handleExchangeError(err error, response []byte, instruction byte) error {
 	errorMsg := err.Error()
 	switch {
 	case errorMsg == "[APDU_CODE_BAD_KEY_HANDLE] The parameters in the data field are incorrect":

common.go

@@ -19,12 +19,10 @@ package ledger_filecoin_go
 import (
 	"encoding/binary"
 	"fmt"
-	"math"
 )
 
 const (
-	userMessageChunkSize = 250
-	publicKeyLength      = 65
+	publicKeyLength = 65
 
 	// Signature-related constants
 	signatureLength    = 65
@@ -115,29 +113,3 @@ func GetBip44bytes(bip44Path []uint32, hardenCount int) ([]byte, error) {
 	}
 	return message, nil
 }
-
-func prepareChunks(bip44PathBytes []byte, transaction []byte) ([][]byte, error) {
-	var packetIndex = 0
-	// first chunk + number of chunk needed for transaction
-	var packetCount = 1 + int(math.Ceil(float64(len(transaction))/float64(userMessageChunkSize)))
-
-	chunks := make([][]byte, packetCount)
-
-	// First chunk is path
-	chunks[0] = bip44PathBytes
-	packetIndex++
-
-	for packetIndex < packetCount {
-		var start = (packetIndex - 1) * userMessageChunkSize
-		var end = packetIndex * userMessageChunkSize
-
-		if end >= len(transaction) {
-			chunks[packetIndex] = transaction[start:]
-		} else {
-			chunks[packetIndex] = transaction[start:end]
-		}
-		packetIndex++
-	}
-
-	return chunks, nil
-}

common_test.go

@@ -17,10 +17,10 @@
 package ledger_filecoin_go
 
 import (
-	"encoding/hex"
 	"fmt"
-	"github.com/stretchr/testify/assert"
 	"testing"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func Test_PrintVersion(t *testing.T) {
@@ -100,22 +100,3 @@ func Test_PathGeneration3(t *testing.T) {
 		fmt.Sprintf("%x", pathBytes),
 		"Unexpected PathBytes\n")
 }
-
-func Test_ChunkGeneration(t *testing.T) {
-	bip44Path := []uint32{44, 123, 0, 0, 0}
-
-	pathBytes, err := GetBip44bytes(bip44Path, 0)
-	if err != nil {
-		t.Fatalf("Detected error, err: %s\n", err.Error())
-	}
-
-	message, _ := hex.DecodeString("885501fd1d0f4dfcd7e99afcb99a8326b7dc459d32c6285501b882619d46558f3d9e316d11b48dcf211327025a0144000186a0430009c4430061a80040")
-
-	chunks, err := prepareChunks(pathBytes, message)
-
-	assert.Equal(
-		t,
-		chunks[0],
-		pathBytes,
-		"First chunk should be pathBytes\n")
-}