Add bambu-nfc dump parse, Key-A HKDF, and spool merge.

Parse filanfc-dump/v1 zip/JSON, Bambu 1K images, and merge stickers by tray UID. dump and mifare packages stay importable for a later common library.

mifare/mifare.go

@@ -0,0 +1,36 @@
+// Package mifare holds MIFARE Classic 1K layout helpers with no brand-specific memory map.
+package mifare
+
+import "fmt"
+
+const (
+	Sectors    = 16
+	Blocks     = 64
+	BlockSize  = 16
+	SectorSize = 64
+	Size1K     = 1024
+)
+
+// SectorOf returns the sector index for a block number (0–63).
+func SectorOf(block int) int {
+	return block / 4
+}
+
+// BlockRange returns the half-open block range [first, last) for a sector.
+func BlockRange(sector int) (first, last int) {
+	first = sector * 4
+	last = first + 4
+	return first, last
+}
+
+// SectorBytes returns the 64-byte slice for sector (0–15) from a 1K image.
+func SectorBytes(image []byte, sector int) ([]byte, error) {
+	if len(image) != Size1K {
+		return nil, fmt.Errorf("image size: want %d got %d", Size1K, len(image))
+	}
+	if sector < 0 || sector >= Sectors {
+		return nil, fmt.Errorf("sector %d out of range", sector)
+	}
+	off := sector * SectorSize
+	return image[off : off+SectorSize], nil
+}

mifare/mifare_test.go

@@ -0,0 +1,30 @@
+package mifare
+
+import "testing"
+
+func TestSectorOfAndBlockRange(t *testing.T) {
+	t.Parallel()
+	if got := SectorOf(9); got != 2 {
+		t.Errorf("SectorOf(9) = %d; want 2", got)
+	}
+	first, last := BlockRange(2)
+	if first != 8 || last != 12 {
+		t.Errorf("BlockRange(2) = %d,%d; want 8,12", first, last)
+	}
+}
+
+func TestSectorBytes(t *testing.T) {
+	t.Parallel()
+	img := make([]byte, Size1K)
+	img[2*SectorSize] = 0xAB
+	got, err := SectorBytes(img, 2)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got[0] != 0xAB || len(got) != SectorSize {
+		t.Errorf("SectorBytes sector 2: len=%d first=%02x", len(got), got[0])
+	}
+	if _, err := SectorBytes(img[:1023], 0); err == nil {
+		t.Fatal("short image: want error")
+	}
+}