Add support for CBOR sequence file format

internal/magic/binary.go

@@ -142,3 +142,117 @@ func Marc(raw []byte, limit uint32) bool {
  // Field terminator is present.
  return bytes.Contains(raw, []byte{0x1E})
 }
+
+func Cbor(raw []byte, limit uint32) bool {
+ if len(raw) == 0 {
+ return false
+ }
+ var ok bool = true
+ for ok {
+ ok = cborHelper(&raw)
+ }
+ if len(raw) == 0 {
+ return true
+ } else {
+ return false
+ }
+}
+
+func cborHelper(raw *[]byte) bool {
+ if len(*raw) == 0 {
+ return false
+ }
+ t := uint8((*raw)[0] & 0xe0)
+ ai := (*raw)[0] & 0x1f
+ uval := uint64(ai)
+ *raw = (*raw)[1:]
+ val, ok := cborHead(raw, t, ai, uval)
+ if ok == false {
+ return ok
+ }
+ switch t {
+ case 0x40, 0x60:
+ if val < 0 {
+ return false
+ }
+ if len(*raw) < val {
+ return false
+ }
+ *raw = (*raw)[val:]
+ case 0x80, 0xa0:
+ if val < 0 {
+ return false
+ }
+ count := 1
+ if t == 0xa0 {
+ count = 2
+ }
+ for i := 0; i < val*count; i++ {
+ if ok = cborHelper(raw); ok == false {
+ return ok
+ }
+ }
+ case 0xc0:
+ for {
+ if len(*raw) == 0 {
+ return false
+ }
+ if uint8((*raw)[0]&0xe0) != 0xc0 {
+ break
+ }
+ }
+ return cborHelper(raw)
+ default:
+ return false
+ }
+ return true
+}
+
+func cborHead(raw *[]byte, t uint8, ai byte, val uint64) (int, bool) {
+ dataLen := len(*raw)
+ if dataLen == 0 {
+ return 0, false
+ }
+ if ai < 24 {
+ return int(val), true
+ }
+ switch ai {
+ case 24:
+ if dataLen < 2 {
+ return 0, false
+ }
+ val = uint64((*raw)[0])
+ *raw = (*raw)[1:]
+ if t == 0xe0 && val < 32 {
+ return 0, false
+ }
+ case 25:
+ if dataLen < 3 {
+ return 0, false
+ }
+ val = uint64(binary.BigEndian.Uint16((*raw)[0 : 2]))
+ *raw = (*raw)[2:]
+ case 26:
+ if dataLen < 5 {
+ return 0, false
+ }
+ val = uint64(binary.BigEndian.Uint32((*raw)[0 : 4]))
+ *raw = (*raw)[4:]
+ case 27:
+ if dataLen < 9 {
+ return 0, false
+ }
+ val = binary.BigEndian.Uint64((*raw)[0 : 8])
+ *raw = (*raw)[8:]
+ case 31:
+ switch t {
+ case 0x00, 0x20, 0xc0:
+ return 0, false
+ case 0xe0:
+ return 0, false
+ }
+ default: // ai == 28, 29, 30
+ return 0, false
+ }
+ return int(val), true
+}

mimetype_test.go

@@ -38,6 +38,7 @@ var files = map[string]string{
  "bpg.bpg": "image/bpg",
  "bz2.bz2": "application/x-bzip2",
  "cab.cab": "application/vnd.ms-cab-compressed",
+ "cbor": "application/cbor-seq",
  "class.class": "application/x-java-applet",
  "crx.crx": "application/x-chrome-extension",
  "csv.csv": "text/csv",

supported_mimes.md

@@ -1,4 +1,4 @@
-## 165 Supported MIME types
+## 166 Supported MIME types
 This file is automatically generated when running tests. Do not edit manually.
 
 Extension | MIME type | Aliases
@@ -135,6 +135,7 @@ Extension | MIME type | Aliases
 **.pat** | image/x-gimp-pat | -
 **.gbr** | image/x-gimp-gbr | -
 **.glb** | model/gltf-binary | -
+**n/a** | application/cbor-seq | -
 **.txt** | text/plain | -
 **.html** | text/html | -
 **.svg** | image/svg+xml | -

testdata/cbor

@@ -0,0 +1 @@
+�t2013-03-21T20:04:00Z�t2013-03-21T20:04:00Z

tree.go

@@ -24,7 +24,7 @@ var root = newMIME("application/octet-stream", "",
  gzip, class, swf, crx, ttf, woff, woff2, otf, eot, wasm, shx, dbf, dcm, rar,
  djvu, mobi, lit, bpg, sqlite3, dwg, nes, lnk, macho, qcp, icns, heic,
  heicSeq, heif, heifSeq, hdr, mrc, mdb, accdb, zstd, cab, rpm, xz, lzip,
- torrent, cpio, tzif, xcf, pat, gbr, glb,
+ torrent, cpio, tzif, xcf, pat, gbr, glb, cbor,
  // Keep text last because it is the slowest check
  text,
 )
@@ -247,4 +247,5 @@ var (
  gbr = newMIME("image/x-gimp-gbr", ".gbr", magic.Gbr)
  xfdf = newMIME("application/vnd.adobe.xfdf", ".xfdf", magic.Xfdf)
  glb = newMIME("model/gltf-binary", ".glb", magic.Glb)
+ cbor = newMIME("application/cbor-seq", "", magic.Cbor)
 )