//Get relocation list of pe file, supports one-word sized relocations only
//If list_absolute_entries = true, IMAGE_REL_BASED_ABSOLUTE will be listed
const relocation_table_list get_relocations(const pe_base& pe, bool list_absolute_entries)
{
relocation_table_list ret;
//If image does not have relocations
if(!pe.has_reloc())
return ret;
//Check the length in bytes of the section containing relocation directory
if(pe.section_data_length_from_rva(pe.get_directory_rva(image_directory_entry_basereloc),
pe.get_directory_rva(image_directory_entry_basereloc), section_data_virtual, true)
< sizeof(image_base_relocation))
throw pe_exception("Incorrect relocation directory", pe_exception::incorrect_relocation_directory);
unsigned long current_pos = pe.get_directory_rva(image_directory_entry_basereloc);
//First IMAGE_BASE_RELOCATION table
image_base_relocation reloc_table = pe.section_data_from_rva<image_base_relocation>(current_pos, section_data_virtual, true);
if(reloc_table.SizeOfBlock % 2)
throw pe_exception("Incorrect relocation directory", pe_exception::incorrect_relocation_directory);
unsigned long reloc_size = pe.get_directory_size(image_directory_entry_basereloc);
unsigned long read_size = 0;
//reloc_table.VirtualAddress is not checked (not so important)
while(reloc_table.SizeOfBlock && read_size < reloc_size)
{
//Create relocation table
relocation_table table;
//Save RVA
table.set_rva(reloc_table.VirtualAddress);
if(!pe_utils::is_sum_safe(current_pos, reloc_table.SizeOfBlock))
throw pe_exception("Incorrect relocation directory", pe_exception::incorrect_relocation_directory);
//List all relocations
for(unsigned long i = sizeof(image_base_relocation); i < reloc_table.SizeOfBlock; i += sizeof(uint16_t))
{
relocation_entry entry(pe.section_data_from_rva<uint16_t>(current_pos + i, section_data_virtual, true));
if(list_absolute_entries || entry.get_type() != image_rel_based_absolute)
table.add_relocation(entry);
}
//Save table
ret.push_back(table);
//Go to next relocation block
if(!pe_utils::is_sum_safe(current_pos, reloc_table.SizeOfBlock))
throw pe_exception("Incorrect relocation directory", pe_exception::incorrect_relocation_directory);
current_pos += reloc_table.SizeOfBlock;
read_size += reloc_table.SizeOfBlock;
if (read_size >= reloc_size)
break;
reloc_table = pe.section_data_from_rva<image_base_relocation>(current_pos, section_data_virtual, true);
}
return ret;
}
//Returns version info property value
//property_name - required property name
//If throw_if_absent = true, will throw exception if property does not exist
//If throw_if_absent = false, will return empty string if property does not exist
const std::wstring version_info_viewer::get_property(const std::wstring& property_name, const std::wstring& translation, bool throw_if_absent) const
{
std::wstring ret;
//If there're no strings
if(strings_.empty())
{
if(throw_if_absent)
throw pe_exception("Version info string does not exist", pe_exception::version_info_string_does_not_exist);
return ret;
}
lang_string_values_map::const_iterator it = strings_.begin();
if(translation.empty())
{
//If no translation was specified
it = strings_.find(default_language_translation); //Find default translation table
if(it == strings_.end()) //If there's no default translation table, take the first one
it = strings_.begin();
}
else
{
it = strings_.find(translation); //Find specified translation table
if(it == strings_.end())
{
if(throw_if_absent)
throw pe_exception("Version info string does not exist", pe_exception::version_info_string_does_not_exist);
return ret;
}
}
//Find value of the required property
string_values_map::const_iterator str_it = (*it).second.find(property_name);
if(str_it == (*it).second.end())
{
if(throw_if_absent)
throw pe_exception("Version info string does not exist", pe_exception::version_info_string_does_not_exist);
return ret;
}
ret = (*str_it).second;
return ret;
}
//Simple relocations rebuilder
//To keep PE file working, don't remove any of existing relocations in
//relocation_table_list returned by a call to get_relocations() function
//auto_strip_last_section - if true and relocations are placed in the last section, it will be automatically stripped
//offset_from_section_start - offset from the beginning of reloc_section, where relocations data will be situated
//If save_to_pe_header is true, PE header will be modified automatically
const image_directory rebuild_relocations(pe_base& pe, const relocation_table_list& relocs, section& reloc_section, uint32_t offset_from_section_start, bool save_to_pe_header, bool auto_strip_last_section)
{
//Check that reloc_section is attached to this PE image
if(!pe.section_attached(reloc_section))
throw pe_exception("Relocations section must be attached to PE file", pe_exception::section_is_not_attached);
uint32_t current_reloc_data_pos = pe_utils::align_up(offset_from_section_start, sizeof(uint32_t));
uint32_t needed_size = current_reloc_data_pos - offset_from_section_start; //Calculate needed size for relocation tables
uint32_t size_delta = needed_size;
uint32_t start_reloc_pos = current_reloc_data_pos;
//Enumerate relocation tables
for(relocation_table_list::const_iterator it = relocs.begin(); it != relocs.end(); ++it)
{
needed_size += static_cast<uint32_t>((*it).get_relocations().size() * sizeof(uint16_t) /* relocations */ + sizeof(image_base_relocation) /* table header */);
//End of each table will be DWORD-aligned
if((start_reloc_pos + needed_size - size_delta) % sizeof(uint32_t))
needed_size += sizeof(uint16_t); //Align it with IMAGE_REL_BASED_ABSOLUTE relocation
}
//Check if reloc_section is last one. If it's not, check if there's enough place for relocations data
if(&reloc_section != &*(pe.get_image_sections().end() - 1) &&
(reloc_section.empty() || pe_utils::align_up(reloc_section.get_size_of_raw_data(), pe.get_file_alignment()) < needed_size + current_reloc_data_pos))
throw pe_exception("Insufficient space for relocations directory", pe_exception::insufficient_space);
std::string& raw_data = reloc_section.get_raw_data();
//This will be done only if reloc_section is the last section of image or for section with unaligned raw length of data
if(raw_data.length() < needed_size + current_reloc_data_pos)
raw_data.resize(pe_utils::align_up(needed_size + current_reloc_data_pos, pe.get_file_alignment())); //Expand section raw data
//Enumerate relocation tables
for(relocation_table_list::const_iterator it = relocs.begin(); it != relocs.end(); ++it)
{
//Create relocation table header
image_base_relocation reloc;
reloc.VirtualAddress = (*it).get_rva();
const relocation_table::relocation_list& reloc_list = (*it).get_relocations();
reloc.SizeOfBlock = static_cast<uint32_t>(sizeof(image_base_relocation) + sizeof(uint16_t) * reloc_list.size());
if((reloc_list.size() * sizeof(uint16_t)) % sizeof(uint32_t)) //If we must align end of relocation table
reloc.SizeOfBlock += sizeof(uint16_t);
memcpy(&raw_data[current_reloc_data_pos], &reloc, sizeof(reloc));
current_reloc_data_pos += sizeof(reloc);
//Enumerate relocations in table
for(relocation_table::relocation_list::const_iterator r = reloc_list.begin(); r != reloc_list.end(); ++r)
{
//Save relocations
uint16_t reloc_value = (*r).get_item();
memcpy(&raw_data[current_reloc_data_pos], &reloc_value, sizeof(reloc_value));
current_reloc_data_pos += sizeof(reloc_value);
}
if(current_reloc_data_pos % sizeof(uint32_t)) //If end of table is not DWORD-aligned
{
memset(&raw_data[current_reloc_data_pos], 0, sizeof(uint16_t)); //Align it with IMAGE_REL_BASED_ABSOLUTE relocation
current_reloc_data_pos += sizeof(uint16_t);
}
}
image_directory ret(pe.rva_from_section_offset(reloc_section, start_reloc_pos), needed_size - size_delta);
//Adjust section raw and virtual sizes
pe.recalculate_section_sizes(reloc_section, auto_strip_last_section);
//If auto-rewrite of PE headers is required
if(save_to_pe_header)
{
pe.set_directory_rva(image_directory_entry_basereloc, ret.get_rva());
pe.set_directory_size(image_directory_entry_basereloc, ret.get_size());
pe.clear_characteristics_flags(image_file_relocs_stripped);
pe.set_dll_characteristics(pe.get_dll_characteristics() | image_dllcharacteristics_dynamic_base);
}
return ret;
}
