Use constant offsets instead of 1-byte arrays

LongSoft · Oct 14, 2021 · d9af12b · d9af12b
1 parent fae9d66
commit d9af12b
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Showing 2 changed files with 10 additions and 6 deletions.
diff --git a/common/ffs.h b/common/ffs.h
@@ -753,9 +753,11 @@ typedef struct CPD_EXT_SIGNED_PACKAGE_INFO_MODULE_ {
     UINT8  HashAlgorithm;
     UINT16 HashSize;
     UINT32 MetadataSize;
-    UINT8  MetadataHash[1]; // Can be 32 or 48 bit
+    // UINT8  MetadataHash[]; with the actual hash size is 32 or 48 bytes
 } CPD_EXT_SIGNED_PACKAGE_INFO_MODULE;
 
+static const size_t CpdExtSignedPkgMetadataHashOffset = sizeof(CPD_EXT_SIGNED_PACKAGE_INFO_MODULE);
+
 typedef struct CPD_EXT_SIGNED_PACKAGE_INFO_ {
     UINT32 ExtensionType;
     UINT32 ExtensionLength;
@@ -774,9 +776,11 @@ typedef struct CPD_EXT_MODULE_ATTRIBUTES_ {
     UINT32 UncompressedSize;
     UINT32 CompressedSize;
     UINT32 GlobalModuleId;
-    UINT8  ImageHash[1]; // The actual hash size is 32 or 48 bytes
+    // UINT8  ImageHash[]; with the actual hash size is 32 or 48 bytes
 } CPD_EXT_MODULE_ATTRIBUTES;
 
+static const size_t CpdExtModuleImageHashOffset = sizeof(CPD_EXT_MODULE_ATTRIBUTES);
+
 #define CPD_EXT_MODULE_COMPRESSION_TYPE_UNCOMPRESSED 0
 #define CPD_EXT_MODULE_COMPRESSION_TYPE_HUFFMAN 1
 #define CPD_EXT_MODULE_COMPRESSION_TYPE_LZMA 2

diff --git a/common/ffsparser.cpp b/common/ffsparser.cpp
@@ -5170,11 +5170,11 @@ USTATUS FfsParser::parseCpdExtensionsArea(const UModelIndex & index)
             // Parse Module Attributes a bit further
             else if (extHeader->Type == CPD_EXT_TYPE_MODULE_ATTRIBUTES) {
                 const CPD_EXT_MODULE_ATTRIBUTES* attrHeader = (const CPD_EXT_MODULE_ATTRIBUTES*)partition.constData();
-                int hashSize = partition.size() - offsetof(CPD_EXT_MODULE_ATTRIBUTES, ImageHash);
+                int hashSize = partition.size() - CpdExtModuleImageHashOffset;
 
                 // This hash is stored reversed
                 // Need to reverse it back to normal
-                UByteArray hash((const char*)&attrHeader->ImageHash, hashSize);
+                UByteArray hash((const char*)attrHeader + CpdExtModuleImageHashOffset, hashSize);
                 std::reverse(hash.begin(), hash.end());
 
                 info = usprintf("Full size: %" PRIXQ "h (%" PRIuQ ")\nType: %Xh\n"
@@ -5226,12 +5226,12 @@ USTATUS FfsParser::parseSignedPackageInfoData(const UModelIndex & index)
         const CPD_EXT_SIGNED_PACKAGE_INFO_MODULE* moduleHeader = (const CPD_EXT_SIGNED_PACKAGE_INFO_MODULE*)(body.constData() + offset);
         if (sizeof(CPD_EXT_SIGNED_PACKAGE_INFO_MODULE) <= ((UINT32)body.size() - offset)) {
             // TODO: check sanity of moduleHeader->HashSize
-            UByteArray module((const char*)moduleHeader, sizeof(CPD_EXT_SIGNED_PACKAGE_INFO_MODULE) - sizeof(moduleHeader->MetadataHash) + moduleHeader->HashSize);
+            UByteArray module((const char*)moduleHeader, CpdExtSignedPkgMetadataHashOffset + moduleHeader->HashSize);
             UString name = usprintf("%.12s", moduleHeader->Name);
 
             // This hash is stored reversed
             // Need to reverse it back to normal
-            UByteArray hash((const char*)&moduleHeader->MetadataHash, moduleHeader->HashSize);
+            UByteArray hash((const char*)moduleHeader + CpdExtSignedPkgMetadataHashOffset, moduleHeader->HashSize);
             std::reverse(hash.begin(), hash.end());
 
             UString info = usprintf("Full size: %" PRIXQ "h (%" PRIuQ ")\nType: %Xh\nHash algorithm: %Xh\nHash size: %Xh (%u)\nMetadata size: %Xh (%u)\nMetadata hash: ",