Initial community commit

Src/nsmkv/header.cpp

@@ -0,0 +1,138 @@
+#include "header.h"
+#include "read.h"
+#include "global_elements.h"
+
+#ifdef WA_VALIDATE
+extern uint64_t max_id_length;
+extern uint64_t max_size_length;
+#endif
+
+// returns bytes read.  0 means EOF
+uint64_t nsmkv::ReadHeader(nsmkv::MKVReader *reader, uint64_t size, nsmkv::Header &header)
+{
+	uint64_t total_bytes_read=0;
+	while (size)
+	{
+		ebml_node node;
+		uint64_t bytes_read = read_ebml_node(reader, &node);
+
+		if (bytes_read == 0)
+			return 0;
+
+		// benski> checking bytes_read and node.size separately prevents possible integer overflow attack
+		if (bytes_read > size)
+			return 0;
+		total_bytes_read+=bytes_read;
+		size-=bytes_read;
+
+		if (node.size > size)
+			return 0;
+		total_bytes_read+=node.size;
+		size-=node.size;
+
+		switch(node.id)
+		{
+		case mkv_header_doctype:
+			{
+				char *utf8=0;
+				if (read_utf8(reader, node.size, &utf8) == 0)
+					return 0;
+
+				header.OwnDocType(utf8);
+#ifdef WA_VALIDATE
+				header.doctype_found = true;
+				printf("  DocType: %s\n", header.doctype);
+#endif
+			}
+			break;
+		case mkv_header_doctype_version:
+			{
+				uint64_t val;
+				if (read_unsigned(reader, node.size, &val) == 0)
+					return 0;
+
+				header.doctype_version = val;
+#ifdef WA_VALIDATE
+				header.doctype_version_found = true;
+				printf("  DocType Version: %I64u\n", header.doctype_version);
+#endif
+			}
+			break;
+		case mkv_header_doctype_read_version:
+			{
+				uint64_t val;
+				if (read_unsigned(reader, node.size, &val) == 0)
+					return 0;
+
+				header.doctype_read_version = val;
+#ifdef WA_VALIDATE
+				header.doctype_read_version_found = true;
+				printf("  DocType Read Version: %I64u\n", header.doctype_read_version);
+#endif
+			}
+			break;
+		case mkv_header_ebml_version:
+			{
+				uint64_t val;
+				if (read_unsigned(reader, node.size, &val) == 0)
+					return 0;
+
+				header.ebml_version = val;
+#ifdef WA_VALIDATE
+				header.ebml_version_found = true;
+				printf("  EBML Version: %I64u\n", header.ebml_version);
+#endif
+			}
+			break;
+		case mkv_header_ebml_read_version:
+			{
+				uint64_t val;
+				if (read_unsigned(reader, node.size, &val) == 0)
+					return 0;
+
+				header.ebml_read_version = val;
+#ifdef WA_VALIDATE
+				header.ebml_read_version_found = true;
+				printf("  EBML Read Version: %I64u\n", header.ebml_read_version);
+#endif
+			}
+			break;
+		case mkv_header_ebml_max_id_length:
+			{
+				uint64_t val;
+				if (read_unsigned(reader, node.size, &val) == 0)
+					return 0;
+
+				header.ebml_max_id_length = val;
+#ifdef WA_VALIDATE
+				max_id_length = val;
+				header.ebml_max_id_length_found = true;
+				printf("  EBML Max ID Length: %I64u\n", header.ebml_max_id_length);
+#endif
+			}
+			break;
+		case mkv_header_ebml_max_size_length:
+			{
+				uint64_t val;
+				if (read_unsigned(reader, node.size, &val) == 0)
+					return 0;
+
+				header.ebml_max_size_length = val;
+#ifdef WA_VALIDATE
+				max_size_length = val;
+				header.ebml_max_size_length_found = true;
+				printf("  EBML Max Size Length: %I64u\n", header.ebml_max_size_length);
+#endif	
+
+			}
+			break;
+		default:
+			{
+				if (ReadGlobal(reader, node.id, node.size) == 0)
+					return 0;
+			}
+		}
+	}
+
+	return total_bytes_read;
+}