Update portable executable and import table validation (#21109)

* Update portable executable and import table validation

Update the SectionAlignment and FileAlignment validate to match the
ms docs...

https://docs.microsoft.com/en-us/windows/win32/debug/pe-format#optional-header-windows-specific-fields-image-only

"SectionAlignment
The alignment (in bytes) of sections when they are loaded into memory
It must be greater than or equal to FileAlignment. The default is the
page size for the architecture."

"FileAlignment
The alignment factor (in bytes) that is used to align the raw data of
sections in the image file. The value should be a power of 2 between 512
and 64 K, inclusive. The default is 512. If the SectionAlignment is less
than the architecture's page size, then FileAlignment must match
SectionAlignment."

For the import table use a case insensitive compare for the mscoree.dll
file name.

* Fixing a error message typo...  

"Aligmnent" to "Alignment"

1 files changed, 18 insertions, 7 deletions

diff --git a/mono/metadata/metadata-verify.c b/mono/metadata/metadata-verify.c
index e83baa4a05e..d50884283b9 100644
--- a/mono/metadata/metadata-verify.c
+++ b/mono/metadata/metadata-verify.c
@@ -448,7 +448,7 @@ static void
 verify_pe_optional_header (VerifyContext *ctx)
 {
 	guint32 offset = pe_header_offset (ctx);
-	guint32 header_size, file_alignment;
+	guint32 header_size, section_alignment, file_alignment;
 	const char *pe_header = ctx->data + offset;
 	const char *pe_optional_header = pe_header + 20;
 
@@ -484,13 +484,19 @@ verify_pe_optional_header (VerifyContext *ctx)
 	/* LAMESPEC MS plays around this value and ignore it during validation
 	if (read32 (pe_optional_header + 28) != 0x400000)
 	ADD_ERROR (ctx, g_strdup_printf ("Invalid Image base %x", read32 (pe_optional_header + 28)));*/
-	if (read32 (pe_optional_header + 32) != 0x2000)
-		ADD_ERROR (ctx, g_strdup_printf ("Invalid Section Aligmnent %x", read32 (pe_optional_header + 32)));
+	section_alignment = read32(pe_optional_header + 32);
 	file_alignment = read32 (pe_optional_header + 36);
-	if (file_alignment != 0x200 && file_alignment != 0x1000)
-		ADD_ERROR (ctx, g_strdup_printf ("Invalid file Aligmnent %x", file_alignment));
+	
+	// a power of 2 between 512 and 64 K, inclusive
+	if (file_alignment != 0x200 && file_alignment != 0x400 && file_alignment != 0x800 && file_alignment != 0x1000 &&
+	    file_alignment != 0x2000 && file_alignment != 0x4000 && file_alignment != 0x8000 && file_alignment != 0x10000)
+		ADD_ERROR (ctx, g_strdup_printf ("Invalid file Alignment %x", file_alignment));
 	/* All the junk in the middle is irrelevant, specially for mono. */
 
+	// must be greater than or equal to FileAlignment
+	if (section_alignment < file_alignment)
+		ADD_ERROR(ctx, g_strdup_printf("Invalid Section Alignment %x", read32(pe_optional_header + 32)));
+
 	if (header_size != 224 + ctx->pe64)
 		ADD_ERROR (ctx, g_strdup_printf ("Invalid optional header size %d", header_size));
 
@@ -622,6 +628,7 @@ verify_import_table (VerifyContext *ctx)
 	guint32 offset = it.translated_offset;
 	const char *ptr = ctx->data + offset;
 	guint32 name_rva, ilt_rva, iat_rva;
+	char mscoreeBuff[SIZE_OF_MSCOREE + 1];
 
 	g_assert (offset != INVALID_OFFSET);
 
@@ -650,8 +657,12 @@ verify_import_table (VerifyContext *ctx)
 		g_assert (name_rva != INVALID_OFFSET);
 		ptr = ctx->data + name_rva;
 	
-		if (memcmp ("mscoree.dll", ptr, SIZE_OF_MSCOREE))
-			ADD_ERROR (ctx, g_strdup_printf ("Invalid Import Table Name: '%s'", ptr));
+		if (memcmp("mscoree.dll", ptr, SIZE_OF_MSCOREE)) {
+			memcpy(mscoreeBuff, ptr, SIZE_OF_MSCOREE);
+			mscoreeBuff[SIZE_OF_MSCOREE] = 0;
+			if (g_strcasecmp ("mscoree.dll", mscoreeBuff))
+				ADD_ERROR(ctx, g_strdup_printf("Invalid Import Table Name: '%s'", ptr));
+		}
 	}
 	
 	if (ilt_rva) {