Fix parsing GLB file with empty Chunk1(BIN data).
diff --git a/tiny_gltf.h b/tiny_gltf.h
index 734c726..0971c18 100644
--- a/tiny_gltf.h
+++ b/tiny_gltf.h
@@ -4113,7 +4113,7 @@
if ((bin_size == 0) || (bin_data == nullptr)) {
if (err) {
- (*err) += "Invalid binary data in `Buffer'.\n";
+ (*err) += "Invalid binary data in `Buffer', or GLB with empty BIN chunk.\n";
}
return false;
}
@@ -6286,15 +6286,15 @@
//
// https://github.com/syoyo/tinygltf/issues/372
// Use 64bit uint to avoid integer overflow.
- uint64_t json_size = 20ull + uint64_t(chunk0_length);
+ uint64_t header_and_json_size = 20ull + uint64_t(chunk0_length);
- if (json_size > std::numeric_limits<uint32_t>::max()) {
+ if (header_and_json_size > std::numeric_limits<uint32_t>::max()) {
// Do not allow 4GB or more GLB data.
(*err) = "Invalid glTF binary. GLB data exceeds 4GB.";
}
- if ((json_size > uint64_t(size)) || (chunk0_length < 1) || (length > size) ||
- (json_size > uint64_t(length)) ||
+ if ((header_and_json_size > uint64_t(size)) || (chunk0_length < 1) || (length > size) ||
+ (header_and_json_size > uint64_t(length)) ||
(chunk0_format != 0x4E4F534A)) { // 0x4E4F534A = JSON format.
if (err) {
(*err) = "Invalid glTF binary.";
@@ -6305,61 +6305,70 @@
// Padding check
// The start and the end of each chunk must be aligned to a 4-byte boundary.
// No padding check for chunk0 start since its 4byte-boundary is ensured.
- if ((json_size % 4) != 0) {
+ if ((header_and_json_size % 4) != 0) {
if (err) {
(*err) = "JSON Chunk end does not aligned to a 4-byte boundary.";
}
}
- // Read Chunk1 info(BIN data)
- if ((json_size + 8ull) > uint64_t(length)) {
- if (err) {
- (*err) = "Insufficient storage space for Chunk1(BIN data).";
+ // Chunk1(BIN) data
+ // The spec says: When the binary buffer is empty or when it is stored by other means, this chunk SHOULD be omitted.
+ if (header_and_json_size <= uint64_t(length)) {
+
+ // Just in case...
+ bin_data_ = nullptr;
+ bin_size_ = 0;
+ } else {
+ // Read Chunk1 info(BIN data)
+ // At least Chunk1 should have 12 bytes(8 bytes(header) + 4 bytes(bin content))
+ if ((header_and_json_size + 12ull) >= uint64_t(length)) {
+ if (err) {
+ (*err) = "Insufficient storage space for Chunk1(BIN data). At least Chunk1 Must have 12bytes or more bytes, but got " + std::to_string((header_and_json_size + 12ull) - uint64_t(length)) + ".\n";
+ }
+ return false;
}
- return false;
- }
- unsigned int chunk1_length; // 4 bytes
- unsigned int chunk1_format; // 4 bytes;
- memcpy(&chunk1_length, bytes + json_size, 4); // JSON data length
- swap4(&chunk1_length);
- memcpy(&chunk1_format, bytes + json_size + 4, 4);
- swap4(&chunk1_format);
+ unsigned int chunk1_length; // 4 bytes
+ unsigned int chunk1_format; // 4 bytes;
+ memcpy(&chunk1_length, bytes + header_and_json_size, 4); // JSON data length
+ swap4(&chunk1_length);
+ memcpy(&chunk1_format, bytes + header_and_json_size + 4, 4);
+ swap4(&chunk1_format);
- if (chunk1_length < 4) {
- // TODO: Do we allow 0byte BIN data?
- if (err) {
- (*err) = "Insufficient Chunk1(BIN) data size.";
+ if (chunk1_length < 4) {
+ if (err) {
+ (*err) = "Insufficient Chunk1(BIN) data size.";
+ }
+ return false;
}
- return false;
- }
- if ((chunk1_length % 4) != 0) {
- if (err) {
- (*err) = "BIN Chunk end does not aligned to a 4-byte boundary.";
+ if ((chunk1_length % 4) != 0) {
+ if (err) {
+ (*err) = "BIN Chunk end does not aligned to a 4-byte boundary.";
+ }
+ return false;
}
- return false;
- }
- if (uint64_t(chunk1_length) + json_size > uint64_t(length)) {
- if (err) {
- (*err) = "BIN Chunk data length exceeds the GLB size.";
+ if (uint64_t(chunk1_length) + header_and_json_size > uint64_t(length)) {
+ if (err) {
+ (*err) = "BIN Chunk data length exceeds the GLB size.";
+ }
+ return false;
}
- return false;
- }
- if (chunk1_format != 0x004e4942) {
- if (err) {
- (*err) = "Invlid type for chunk1 data.";
+ if (chunk1_format != 0x004e4942) {
+ if (err) {
+ (*err) = "Invlid type for chunk1 data.";
+ }
+ return false;
}
- return false;
+
+ bin_data_ = bytes + header_and_json_size +
+ 8; // 4 bytes (bin_buffer_length) + 4 bytes(bin_buffer_format)
+
+ bin_size_ = size_t(chunk1_length);
}
- bin_data_ = bytes + json_size +
- 8; // 4 bytes (bin_buffer_length) + 4 bytes(bin_buffer_format)
-
- bin_size_ = size_t(chunk1_length);
-
// Extract JSON string.
std::string jsonString(reinterpret_cast<const char *>(&bytes[20]),
chunk0_length);
