Fix a PE analyzer failure where the IAT isn't aligned with a section boundary.

src/file_analysis/analyzer/pe/PE.cc

@@ -18,6 +18,8 @@ PE::~PE()
 
 bool PE::DeliverStream(const u_char* data, uint64 len)
 	{
+	if ( conn->is_done() )
+		return true;
 	try
 		{
 		interp->NewData(data, data + len);

src/file_analysis/analyzer/pe/events.bif

@@ -1,5 +1,11 @@
 event pe_dos_header%(f: fa_file, h: PE::DOSHeader%);
+
 event pe_dos_code%(f: fa_file, code: string%);
+
 event pe_file_header%(f: fa_file, h: PE::FileHeader%);
+
 event pe_optional_header%(f: fa_file, h: PE::OptionalHeader%);
-event pe_section_header%(f: fa_file, h: PE::SectionHeader%);
+
+event pe_section_header%(f: fa_file, h: PE::SectionHeader%);
+
+event pe_import_entry%(f: fa_file, m: string, name: string%);

src/file_analysis/analyzer/pe/pe-analyzer.pac

@@ -174,13 +174,23 @@ refine flow File += {
 		return true;
 		%}
 
-
-	function proc_pe_file(): bool
+	function proc_import_entry(module_name: bytestring, i: import_entry): bool
 		%{
-		printf("PE file processed\n");
+		if ( pe_import_entry )
+			{
+			StringVal* name;
+			if ( ${i.name}.length() > 1 )
+				name = new StringVal(${i.name}.length() - 1, (const char*) ${i.name}.begin());
+			else
+				name = new StringVal(0, (const char*) ${i.name}.begin());
+			
+			BifEvent::generate_pe_import_entry((analyzer::Analyzer *) connection()->bro_analyzer(), 
+			                                   connection()->bro_analyzer()->GetFile()->GetVal()->Ref(),
+			                                   bytestring_to_val(${module_name}),
+				                           name);
+			}
 		return true;
 		%}
-
 };
 
 refine typeattr DOS_Header += &let {
@@ -204,10 +214,9 @@ refine typeattr Optional_Header += &let {
 };
 
 refine typeattr Section_Header += &let {
-	proc2: bool = $context.flow.proc_section_header(this);
+	proc: bool = $context.flow.proc_section_header(this);
 };
 
-refine typeattr PE_File += &let {
-	proc: bool = $context.flow.proc_pe_file();
+refine typeattr import_entry += &let {
+	proc: bool = $context.flow.proc_import_entry($context.connection.get_module_name(), this) &if(!is_module);
 };
-

src/file_analysis/analyzer/pe/pe-file-headers.pac

@@ -39,7 +39,7 @@ type DOS_Code(len: uint32) = record {
 type NT_Headers = record {
 	PESignature     : uint32;
 	file_header     : File_Header;
-	optional_header : Optional_Header(file_header.SizeOfOptionalHeader, file_header.NumberOfSections) &length=file_header.SizeOfOptionalHeader;
+	optional_header : Optional_Header &length=file_header.SizeOfOptionalHeader;
 } &let {
 	length: uint32 = file_header.SizeOfOptionalHeader+offsetof(optional_header);
 } &length=length;
@@ -56,7 +56,7 @@ type File_Header = record {
 };
 
 # The optional header gives us DLL link information, and some structural information
-type Optional_Header(len: uint16, number_of_sections: uint16) = record {
+type Optional_Header = record {
 	magic                   : uint16;
 	major_linker_version    : uint8;
 	minor_linker_version    : uint8;
@@ -68,11 +68,11 @@ type Optional_Header(len: uint16, number_of_sections: uint16) = record {
 	have_base_of_data: case pe_format of {
 		PE32    -> base_of_data: uint32;
 		default -> not_present:  empty;
-	};
+	} &requires(pe_format);
 	is_pe32: case pe_format of {
 		PE32_PLUS -> image_base_64: uint64;
 		default   -> image_base_32: uint32;
-	};
+	} &requires(pe_format);
 	section_alignment       : uint32;
 	file_alignment          : uint32;
 	os_version_major        : uint16;
@@ -91,14 +91,14 @@ type Optional_Header(len: uint16, number_of_sections: uint16) = record {
 		PE32      -> i32: Mem_Info32;
 		PE32_PLUS -> i64: Mem_Info64;
 		default -> InvalidPEFile : empty;
-	};
+	} &requires(pe_format);
 	loader_flags            : uint32;
 	number_of_rva_and_sizes : uint32;
 	rvas			: RVAS(number_of_rva_and_sizes);
 } &let {
 	pe_format: uint8 = $context.connection.set_pe32_format(magic);
 	image_base: uint64 = pe_format == PE32_PLUS ? image_base_64 : image_base_32;
-} &length=len;
+};
 
 type Section_Headers(num: uint16) = record {
 	sections : Section_Header[num];
@@ -118,7 +118,7 @@ type Section_Header = record {
 	non_used_num_of_line_nums : uint16;
 	characteristics           : uint32;
 } &let {
-	proc: bool = $context.connection.proc_section(this);
+	add_section: bool = $context.connection.add_section(this);
 } &length=40;
 
 refine connection MockConnection += {
@@ -132,13 +132,13 @@ refine connection MockConnection += {
 		pe32_format_ = UNKNOWN_VERSION;;
 	%}
 
-	function proc_section(h: Section_Header): bool
+	function add_section(h: Section_Header): bool
 		%{
 		if ( ${h.size_of_raw_data} + ${h.ptr_to_raw_data} > max_file_location_ )
 			max_file_location_ = ${h.size_of_raw_data} + ${h.ptr_to_raw_data};
 		
-		if ( ${h.virtual_addr} > 0 && ${h.virtual_addr} == import_table_rva_ )
-			import_table_va_ = ${h.ptr_to_raw_data};
+		if ( ${h.virtual_addr} > 0 && ${h.virtual_addr} <= import_table_rva_ && ( ${h.virtual_addr} + ${h.virtual_size} ) > import_table_rva_ )
+			import_table_va_ = ${h.ptr_to_raw_data} + (import_table_rva_ - ${h.virtual_addr});
 		return true;
 		%}
 

src/file_analysis/analyzer/pe/pe-file-idata.pac

@@ -29,12 +29,12 @@ type import_lookup_table = record {
 type import_entry(is_module: bool, pad_align: uint8) = record {
 	pad: bytestring &length=pad_align;
 	has_index: case is_module of {
-		true -> null: empty;
+		true  -> null: empty;
 		false -> index: uint16;
 	};
 	name: null_terminated_string;
 } &let {
-	proc: bool = $context.connection.proc_import_hint(name);
+	proc_align: bool = $context.connection.proc_import_hint(name, is_module);
 };
 
 type idata = record {
@@ -63,6 +63,9 @@ refine connection MockConnection += {
 		uint32 next_hint_index_;
 		uint8 next_hint_align_;
 		bool next_hint_is_module_;
+
+		// Track the module name, so we know what each import's for
+		bytestring module_name_;
 	%}
 
 	%init{
@@ -73,6 +76,12 @@ refine connection MockConnection += {
 		next_hint_is_module_ = true;
 		next_hint_index_ = 0;
 		next_hint_align_ = 0;
+
+		module_name_ = bytestring();
+	%}
+
+	%cleanup{
+		module_name_.free();
 	%}
 
 	# When we read the section header, store the relative virtual address and
@@ -101,10 +110,15 @@ refine connection MockConnection += {
 		%}		
 
 	# We need to calculate the length of the next padding field
-	function proc_import_hint(hint_name: bytestring): bool
+	function proc_import_hint(hint_name: bytestring, is_module: bool): bool
 		%{
 		next_hint_align_ = ${hint_name}.length() % 2;
-		printf("Imported %s\n", ${hint_name}.data());
+		if ( is_module && ${hint_name}.length() > 1 )
+			{
+			module_name_.clear();
+			module_name_.init(${hint_name}.data(), ${hint_name}.length() - 1);
+			}
+			
 		return true;
 		%}
 
@@ -129,6 +143,11 @@ refine connection MockConnection += {
 		return next_hint_index_ == imports_per_module_.size();
 		%}
 
+	function get_module_name(): bytestring
+		%{
+		return module_name_;
+		%}
+
 	function get_import_table_addr(): uint32
 		%{
 		return import_table_va_ > 0 ? import_table_va_ : 0;

src/file_analysis/analyzer/pe/pe-file-types.pac

@@ -35,4 +35,3 @@ type Padding(length: uint64) = record {
 };
 
 type null_terminated_string = RE/[A-Za-z0-9.]+\x00/;
-

src/file_analysis/analyzer/pe/pe-file.pac

@@ -3,7 +3,12 @@
 %include pe-file-idata.pac
 
 # The base record for a Portable Executable file
-type PE_File = record {
+type PE_File = case $context.connection.is_done() of {
+	false -> PE      : Portable_Executable;
+	true  -> overlay : bytestring &length=1 &transient;
+};
+
+type Portable_Executable = record {
 	headers : Headers;
 	pad1	: Padding(iat_loc);
 	iat     : idata &length=$context.connection.get_import_table_len();
@@ -12,5 +17,27 @@ type PE_File = record {
 	unparsed_hdr_len: uint32 = headers.pe_header.optional_header.size_of_headers - headers.length;
 	iat_loc: uint64 = $context.connection.get_import_table_addr() - headers.pe_header.optional_header.size_of_headers + unparsed_hdr_len;
 	restofdata: uint64 = $context.connection.get_max_file_location() - $context.connection.get_import_table_addr() - $context.connection.get_import_table_len();
+	proc: bool = $context.connection.proc_pe(this);
 } &byteorder=littleendian;
 
+refine connection MockConnection += {
+
+	%member{
+		bool done_;
+	%}
+
+	%init{
+		done_ = false;
+	%}
+
+	function proc_pe(p: Portable_Executable): bool
+		%{
+		done_ = true;
+		return true;
+		%}
+
+	function is_done(): bool
+		%{
+		return done_;
+		%}
+};