feat(comm_d): verify_seal no longer needs pieces, just comm_d (#41)

- also expose a function to compute comm_d from pieces

bindings.go

@@ -166,7 +166,6 @@ func VerifySeal(
 	seed [32]byte,
 	sectorID uint64,
 	proof []byte,
-	pieces []PublicPieceInfo,
 ) (bool, error) {
 	defer elapsed("VerifySeal")()
 
@@ -188,9 +187,6 @@ func VerifySeal(
 	seedCBytes := C.CBytes(seed[:])
 	defer C.free(seedCBytes)
 
-	cPiecesPtr, cPiecesLen := cPublicPieceInfo(pieces)
-	defer C.free(unsafe.Pointer(cPiecesPtr))
-
 	// a mutable pointer to a VerifySealResponse C-struct
 	resPtr := C.sector_builder_ffi_verify_seal(
 		C.uint64_t(sectorSize),
@@ -202,8 +198,6 @@ func VerifySeal(
 		(*[32]C.uint8_t)(seedCBytes),
 		(*C.uint8_t)(proofCBytes),
 		C.size_t(len(proof)),
-		(*C.sector_builder_ffi_FFIPublicPieceInfo)(cPiecesPtr),
-		cPiecesLen,
 	)
 	defer C.sector_builder_ffi_destroy_verify_seal_response(resPtr)
 
@@ -694,6 +688,26 @@ func GeneratePieceCommitment(piecePath string, pieceSize uint64) ([CommitmentByt
 	return GeneratePieceCommitmentFromFile(pieceFile, pieceSize)
 }
 
+// GenerateDataCommitment produces a commitment for the sector containing the
+// provided pieces.
+func GenerateDataCommitment(sectorSize uint64, pieces []PublicPieceInfo) ([CommitmentBytesLen]byte, error) {
+	cPiecesPtr, cPiecesLen := cPublicPieceInfo(pieces)
+	defer C.free(unsafe.Pointer(cPiecesPtr))
+
+	resPtr := C.sector_builder_ffi_generate_data_commitment(C.uint64_t(sectorSize), (*C.sector_builder_ffi_FFIPublicPieceInfo)(cPiecesPtr), cPiecesLen)
+	defer C.sector_builder_ffi_destroy_generate_data_commitment_response(resPtr)
+
+	if resPtr.status_code != 0 {
+		return [CommitmentBytesLen]byte{}, errors.New(C.GoString(resPtr.error_msg))
+	}
+
+	commDSlice := goBytes(&resPtr.comm_d[0], CommitmentBytesLen)
+	var commitment [CommitmentBytesLen]byte
+	copy(commitment[:], commDSlice)
+
+	return commitment, nil
+}
+
 // GeneratePieceCommitmentFromFile produces a piece commitment for the provided data
 // stored in a given file.
 func GeneratePieceCommitmentFromFile(pieceFile *os.File, pieceSize uint64) (commP [CommitmentBytesLen]byte, err error) {

bindings_test.go

@@ -89,6 +89,9 @@ func TestSectorBuilderLifecycle(t *testing.T) {
 		CommP: commP,
 	}}
 
+	preComputedCommD, err := sb.GenerateDataCommitment(1024, publicPieceInfoA)
+	require.NoError(t, err)
+
 	// seek to the beginning
 	_, err = pieceFileA.Seek(0, 0)
 	require.NoError(t, err)
@@ -113,6 +116,7 @@ func TestSectorBuilderLifecycle(t *testing.T) {
 		require.NoError(t, err)
 		require.Equal(t, sectorIDA, out.SectorID)
 		require.Equal(t, ticketA.TicketBytes, out.Ticket.TicketBytes)
+		require.True(t, bytes.Equal(preComputedCommD[:], out.CommD[:]))
 	}()
 
 	// write a second piece to a staged sector, reducing remaining space to 0
@@ -161,7 +165,7 @@ func TestSectorBuilderLifecycle(t *testing.T) {
 	require.Equal(t, seedB.TicketBytes, statusB.Seed.TicketBytes)
 
 	// verify the seal proof
-	isValid, err := sb.VerifySeal(1024, statusA.CommR, statusA.CommD, proverID, ticketA.TicketBytes, seedA.TicketBytes, sectorIDA, statusA.Proof, publicPieceInfoA)
+	isValid, err := sb.VerifySeal(1024, statusA.CommR, statusA.CommD, proverID, ticketA.TicketBytes, seedA.TicketBytes, sectorIDA, statusA.Proof)
 	require.NoError(t, err)
 	require.True(t, isValid)
 

rust-fil-sector-builder @ 0bb1e071

-Subproject commit 8ed121f63c40e692860644c93c5cd76ea16c58a0
+Subproject commit 0bb1e071fffff861d388109e119a24f5a202bd36