//Rebuild PE image and write it to "out" ostream
//If strip_dos_header is true, DOS headers partially will be used for PE headers
//If change_size_of_headers == true, SizeOfHeaders will be recalculated automatically
//If save_bound_import == true, existing bound import directory will be saved correctly (because some compilers and bind.exe put it to PE headers)
void rebuild_pe(pe_base& pe, std::ostream& out, bool strip_dos_header, bool change_size_of_headers, bool save_bound_import)
{
if(out.bad())
throw pe_exception("Stream is bad", pe_exception::stream_is_bad);
if(save_bound_import && pe.has_bound_import())
{
if(pe.section_data_length_from_rva(pe.get_directory_rva(image_directory_entry_bound_import), pe.get_directory_rva(image_directory_entry_bound_import), section_data_raw, true)
< pe.get_directory_size(image_directory_entry_bound_import))
throw pe_exception("Incorrect bound import directory", pe_exception::incorrect_bound_import_directory);
}
//Change ostream state
out.exceptions(std::ios::goodbit);
out.clear();
uint32_t original_bound_import_rva = pe.has_bound_import() ? pe.get_directory_rva(image_directory_entry_bound_import) : 0;
if(original_bound_import_rva && original_bound_import_rva > pe.get_size_of_headers())
{
//No need to do anything with bound import directory
//if it is placed inside of any section, not headers
original_bound_import_rva = 0;
save_bound_import = false;
}
{
image_dos_header dos_header;
//Rebuild PE image headers
rebuild_pe(pe, dos_header, strip_dos_header, change_size_of_headers, save_bound_import);
//Write DOS header
out.write(reinterpret_cast<const char*>(&dos_header), strip_dos_header ? 8 * sizeof(uint16_t) : sizeof(image_dos_header));
}
//If we have stub overlay, write it too
{
const std::string& stub = pe.get_stub_overlay();
if(stub.size())
{
out.write(stub.data(), stub.size());
size_t aligned_size = pe_utils::align_up(stub.size(), sizeof(uint32_t));
//Align PE header, which is right after rich overlay
while(aligned_size > stub.size())
{
out.put('\0');
--aligned_size;
}
}
}
//Write NT headers
out.write(static_cast<const pe_base&>(pe).get_nt_headers_ptr(), pe.get_sizeof_nt_header()
- sizeof(image_data_directory) * (image_numberof_directory_entries - pe.get_number_of_rvas_and_sizes()));
//Write section headers
const section_list& sections = pe.get_image_sections();
for(section_list::const_iterator it = sections.begin(); it != sections.end(); ++it)
{
out.write(reinterpret_cast<const char*>(&(*it).get_raw_header()), sizeof(image_section_header));
}
//Write bound import data if requested
if(save_bound_import && pe.has_bound_import())
{
out.write(pe.section_data_from_rva(original_bound_import_rva, section_data_raw, true),
pe.get_directory_size(image_directory_entry_bound_import));
}
//Write section data finally
for(section_list::const_iterator it = sections.begin(); it != sections.end(); ++it)
{
const section& s = *it;
std::streamoff wpos = out.tellp();
//Fill unused overlay data between sections with null bytes
for(unsigned int i = 0; i < s.get_pointer_to_raw_data() - wpos; i++)
out.put(0);
//Write raw section data
out.write(s.get_raw_data().data(), s.get_size_of_raw_data());
}
}
const bound_import_module_list get_bound_import_module_list(const pe_base& pe)
{
//Returned bound import modules list
bound_import_module_list ret;
//If image has no bound imports
if(!pe.has_bound_import())
return ret;
uint32_t bound_import_data_len =
pe.section_data_length_from_rva(pe.get_directory_rva(image_directory_entry_bound_import), pe.get_directory_rva(image_directory_entry_bound_import), section_data_raw, true);
if(bound_import_data_len < pe.get_directory_size(image_directory_entry_bound_import))
throw pe_exception("Incorrect bound import directory", pe_exception::incorrect_bound_import_directory);
const char* bound_import_data = pe.section_data_from_rva(pe.get_directory_rva(image_directory_entry_bound_import), section_data_raw, true);
//Check read in "read_pe" function raw bound import data size
if(bound_import_data_len < sizeof(image_bound_import_descriptor))
throw pe_exception("Incorrect bound import directory", pe_exception::incorrect_bound_import_directory);
//current bound_import_data_ in-string position
unsigned long current_pos = 0;
//first bound import descriptor
//so, we're working with raw data here, no section helpers available
const image_bound_import_descriptor* descriptor = reinterpret_cast<const image_bound_import_descriptor*>(&bound_import_data[current_pos]);
//Enumerate until zero
while(descriptor->OffsetModuleName)
{
//Check module name offset
if(descriptor->OffsetModuleName >= bound_import_data_len)
throw pe_exception("Incorrect bound import directory", pe_exception::incorrect_bound_import_directory);
//Check module name for null-termination
if(!pe_utils::is_null_terminated(&bound_import_data[descriptor->OffsetModuleName], bound_import_data_len - descriptor->OffsetModuleName))
throw pe_exception("Incorrect bound import directory", pe_exception::incorrect_bound_import_directory);
//Create bound import descriptor structure
bound_import elem(&bound_import_data[descriptor->OffsetModuleName], descriptor->TimeDateStamp);
//Check DWORDs
if(descriptor->NumberOfModuleForwarderRefs >= pe_utils::max_dword / sizeof(image_bound_forwarder_ref)
|| !pe_utils::is_sum_safe(current_pos, 2 /* this descriptor and the next one */ * sizeof(image_bound_import_descriptor) + descriptor->NumberOfModuleForwarderRefs * sizeof(image_bound_forwarder_ref)))
throw pe_exception("Incorrect bound import directory", pe_exception::incorrect_bound_import_directory);
//Move after current descriptor
current_pos += sizeof(image_bound_import_descriptor);
//Enumerate referenced bound import descriptors
for(unsigned long i = 0; i != descriptor->NumberOfModuleForwarderRefs; ++i)
{
//They're just after parent descriptor
//Check size of structure
if(current_pos + sizeof(image_bound_forwarder_ref) > bound_import_data_len)
throw pe_exception("Incorrect bound import directory", pe_exception::incorrect_bound_import_directory);
//Get IMAGE_BOUND_FORWARDER_REF pointer
const image_bound_forwarder_ref* ref_descriptor = reinterpret_cast<const image_bound_forwarder_ref*>(&bound_import_data[current_pos]);
//Check referenced module name
if(ref_descriptor->OffsetModuleName >= bound_import_data_len)
throw pe_exception("Incorrect bound import directory", pe_exception::incorrect_bound_import_directory);
//And its null-termination
if(!pe_utils::is_null_terminated(&bound_import_data[ref_descriptor->OffsetModuleName], bound_import_data_len - ref_descriptor->OffsetModuleName))
throw pe_exception("Incorrect bound import directory", pe_exception::incorrect_bound_import_directory);
//Add referenced module to current bound import structure
elem.add_module_ref(bound_import_ref(&bound_import_data[ref_descriptor->OffsetModuleName], ref_descriptor->TimeDateStamp));
//Move after referenced bound import descriptor
current_pos += sizeof(image_bound_forwarder_ref);
}
//Check structure size
if(current_pos + sizeof(image_bound_import_descriptor) > bound_import_data_len)
throw pe_exception("Incorrect bound import directory", pe_exception::incorrect_bound_import_directory);
//Move to next bound import descriptor
descriptor = reinterpret_cast<const image_bound_import_descriptor*>(&bound_import_data[current_pos]);
//Save created descriptor structure and references
ret.push_back(elem);
}
//Return result
return ret;
}
//Rebuilds PE image headers
//If strip_dos_header is true, DOS headers partially will be used for PE headers
//If change_size_of_headers == true, SizeOfHeaders will be recalculated automatically
//If save_bound_import == true, existing bound import directory will be saved correctly (because some compilers and bind.exe put it to PE headers)
void rebuild_pe(pe_base& pe, image_dos_header& dos_header, bool strip_dos_header, bool change_size_of_headers, bool save_bound_import)
{
dos_header = pe.get_dos_header();
if(strip_dos_header)
{
//Strip stub overlay
pe.strip_stub_overlay();
//BaseOfCode NT Headers field now overlaps
//e_lfanew field, so we're acrually setting
//e_lfanew with this call
pe.set_base_of_code(8 * sizeof(uint16_t));
}
else
{
//Set start of PE headers
dos_header.e_lfanew = sizeof(image_dos_header)
+ pe_utils::align_up(static_cast<uint32_t>(pe.get_stub_overlay().size()), sizeof(uint32_t));
}
section_list& sections = pe.get_image_sections();
//Calculate pointer to section data
size_t ptr_to_section_data = (strip_dos_header ? 8 * sizeof(uint16_t) : sizeof(image_dos_header)) + pe.get_sizeof_nt_header()
+ pe_utils::align_up(pe.get_stub_overlay().size(), sizeof(uint32_t))
- sizeof(image_data_directory) * (image_numberof_directory_entries - pe.get_number_of_rvas_and_sizes())
+ sections.size() * sizeof(image_section_header);
if(save_bound_import && pe.has_bound_import())
{
//It will be aligned to DWORD, because we're aligning to DWORD everything above it
pe.set_directory_rva(image_directory_entry_bound_import, static_cast<uint32_t>(ptr_to_section_data));
ptr_to_section_data += pe.get_directory_size(image_directory_entry_bound_import);
}
ptr_to_section_data = pe_utils::align_up(ptr_to_section_data, pe.get_file_alignment());
//Set size of headers and size of optional header
if(change_size_of_headers)
{
if(!pe.get_image_sections().empty())
{
if(static_cast<uint32_t>(ptr_to_section_data) > (*sections.begin()).get_virtual_address())
throw pe_exception("Headers of PE file are too long. Try to strip STUB or don't build bound import", pe_exception::cannot_rebuild_image);
}
pe.set_size_of_headers(static_cast<uint32_t>(ptr_to_section_data));
}
//Set number of sections in PE header
pe.update_number_of_sections();
pe.update_image_size();
pe.set_size_of_optional_header(static_cast<uint16_t>(pe.get_sizeof_opt_headers()
- sizeof(image_data_directory) * (image_numberof_directory_entries - pe.get_number_of_rvas_and_sizes())));
//Recalculate pointer to raw data according to section list
for(section_list::iterator it = sections.begin(); it != sections.end(); ++it)
{
//Save section headers PointerToRawData
if((*it).get_size_of_raw_data())
{
(*it).set_pointer_to_raw_data(static_cast<uint32_t>(ptr_to_section_data));
ptr_to_section_data += (*it).get_aligned_raw_size(pe.get_file_alignment());
}
}
}