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/******************************************************************************/
/* Copyright (c) 2016, The Linux Foundation. All rights reserved. */
/* */
/* Redistribution and use in source and binary forms, with or without */
/* modification, are permitted provided that the following conditions are */
/* met: */
/* * Redistributions of source code must retain the above copyright */
/* notice, this list of conditions and the following disclaimer. */
/* * Redistributions in binary form must reproduce the above */
/* copyright notice, this list of conditions and the following */
/* disclaimer in the documentation and/or other materials provided */
/* with the distribution. */
/* * Neither the name of The Linux Foundation nor the names of its */
/* contributors may be used to endorse or promote products derived */
/* from this software without specific prior written permission. */
/* */
/* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED */
/* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT */
/* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS */
/* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR */
/* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF */
/* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR */
/* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, */
/* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE */
/* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN */
/* IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
/******************************************************************************/
#include <iostream>
#include "elfio/elfio.hpp"
using namespace ELFIO;
/*----------------------------------------------------------------------------
* Definitions and macros
*-------------------------------------------------------------------------*/
#define HASH_CODE_SIZE 0x80
#define SIGNATURE_SIZE 0x100
#define CERT_CHAIN_SIZE 0x1800
#define MAX_CERT_CHAIN_SIZE 0x19A8
#define SHT_QC 0x70000003
#define SHT_EXIDX 0x70000001
#define HASH_SE_ALIGN 0x1000
#define HASH_SE_FLAG 0x2200000
#define MI_PBT_FLAG_SEGMENT_TYPE_MASK 0x7000000
#define MI_PBT_FLAG_SEGMENT_TYPE_SHIFT 0x18
/*----------------------------------------------------------------------------
* Type declerations
*-------------------------------------------------------------------------*/
typedef unsigned char uint8;
typedef unsigned int uint32 ;
typedef unsigned long long uint64 ;
/* struct to store hash segment header */
typedef struct
{
unsigned int header_vsn_num; /* Header version number. */
unsigned int image_id; /* Identifies the type of image this header represents . */
unsigned int image_src; /* Location of image in flash. */
unsigned int image_dest_ptr; /* Pointer to location to store image in RAM.*/
unsigned int image_size; /* Size of complete image in bytes */
unsigned int code_size; /* Size of code region of image in bytes */
unsigned int signature_ptr; /* Pointer to images attestation signature */
unsigned int signature_size; /* Size of the attestation signature in bytes */
unsigned int cert_chain_ptr; /* Pointer to the certificates associated with the image. */
unsigned int cert_chain_size; /* Size of the attestation chain in bytes */
} mi_boot_image_header_type;
/*----------------------------------------------------------------------------
* Static helper functions
*-------------------------------------------------------------------------*/
/* This function writes data to file */
static uint32 saveDataToFile(std::string file_name, const char *data, uint32 len)
{
std::ofstream ostreamfile;
ostreamfile.open( file_name, std::ios::out | std::ios::binary );
if ( !ostreamfile ) {
std::cout << "cant open data To Sig file"<< file_name << std::endl;
return 1;
}
ostreamfile.write(data,len);
ostreamfile.close();
return 0;
}
/*----------------------------------------------------------------------------
* Main functions
*-------------------------------------------------------------------------*/
int main( int argc, char** argv )
{
if ( argc != 4 ) {
std::cout << "Usage: signlk <unsigned_elf_file> <signed_elf_file> <tmp_dir>"<< std::endl;
return 1;
}
/* Create an elfio reader and writer */
elfio reader;
elfio writer;
std::ifstream stream;
std::ofstream ostreamfile;
char cert_chain[MAX_CERT_CHAIN_SIZE]={0};
unsigned int hash_segment_address = 0;
std::string tmp_path=(std::string)(argv[3]);
mi_boot_image_header_type mi={0};
section* data_sec = NULL;
section* mi_sec = NULL;
segment* header_seg = NULL;
segment* hash_seg = NULL;
segment* orig_hash_seg = NULL;
Elf_Xword wflags =0;
Elf_Word maxAddress = 0;
segment* max_seg = NULL;
uint32 hash_offset = 2;
char elfHeader[0x1000];
Elf_Half seg_num=0;
char Si[8] ={0x36,0x36,0x36,0x36,0x36,0x36,0x36,0x3F};
char So[8] ={0x5C,0x5C,0x5C,0x5C,0x5C,0x5C,0x5C,0x5C};
/* Load ELF data */
if ( !reader.load( argv[1] ) ) {
std::cout << "Can't find or process ELF file " << argv[1] << std::endl;
return 2;
}
/* create a write configuration */
writer.create( reader.get_class(), reader.get_encoding() );
writer.set_os_abi( reader.get_os_abi() );
writer.set_type( reader.get_type() );
writer.set_machine( reader.get_machine() );
writer.set_flags(reader.get_flags());
seg_num = reader.segments.size();
/* Create hash data section*/
header_seg = writer.segments.add();
hash_seg = writer.segments.add();
/* Init the certificates chain file */
for ( int i = 0; i < MAX_CERT_CHAIN_SIZE; ++i ) cert_chain[i]=0xff;
/* Find the hash segment in the input file */
for ( int i = 0; i < seg_num; ++i ) {
segment* pseg = reader.segments[i];
wflags = pseg->get_flags() ;
if (((wflags&MI_PBT_FLAG_SEGMENT_TYPE_MASK)>>MI_PBT_FLAG_SEGMENT_TYPE_SHIFT) == 0x2){
orig_hash_seg = pseg;
hash_segment_address = pseg->get_virtual_address();
hash_offset = 0;
break;
}
if (pseg->get_physical_address() > maxAddress)
{
maxAddress = pseg->get_physical_address();
max_seg = pseg;
}
}
/* Fill hash segment with empty section */
hash_seg->set_type( PT_NULL);
hash_seg->set_virtual_address( hash_segment_address );
hash_seg->set_physical_address( hash_segment_address);
hash_seg->set_flags( HASH_SE_FLAG );
hash_seg->set_align( HASH_SE_ALIGN );
hash_seg->set_file_size(mi.image_size);
hash_seg->set_memory_size(MAX_CERT_CHAIN_SIZE);
mi_sec = writer.sections.add( ".mi" );
mi_sec->set_type( PT_LOPROC );
mi_sec->set_flags( SHF_ALLOC );
mi_sec->set_addr_align( HASH_SE_ALIGN );
/* Create a hash segment if needed */
if (orig_hash_seg == NULL){
hash_segment_address = (maxAddress + max_seg->get_memory_size());
hash_segment_address += HASH_SE_ALIGN - (hash_segment_address % HASH_SE_ALIGN);
}
/* set the hash segment header data */
mi.image_id = 0x3;
mi.image_dest_ptr = hash_segment_address + sizeof(mi_boot_image_header_type);
mi.code_size = HASH_CODE_SIZE;
mi.header_vsn_num = 0;
mi.signature_ptr = mi.image_dest_ptr + mi.code_size;
mi.signature_size =SIGNATURE_SIZE;
mi.cert_chain_ptr = mi.signature_ptr + mi.signature_size;
mi.cert_chain_size = CERT_CHAIN_SIZE;
mi.image_size = mi.cert_chain_size + mi.signature_size + mi.code_size;
memcpy(cert_chain,&mi,sizeof(mi));
mi_sec->set_data(cert_chain,MAX_CERT_CHAIN_SIZE);
/* Add code section into program segment */
hash_seg->add_section_index( mi_sec->get_index(), mi_sec->get_addr_align() );
/* copy the original elf segments to the signed elf */
for ( int i = 0; i < seg_num; ++i ) {
segment* pseg = reader.segments[i];
wflags = pseg->get_flags() ;
if (wflags & HASH_SE_FLAG) continue;
segment* data_seg = writer.segments.add();
data_seg->set_type( pseg->get_type() );
data_seg->set_virtual_address( pseg->get_virtual_address() );
data_seg->set_physical_address( pseg->get_physical_address() );
data_seg->set_flags( pseg->get_flags() );
data_seg->set_align( pseg->get_align() );
data_seg->set_file_size(pseg->get_file_size());
data_seg->set_memory_size(pseg->get_memory_size());
data_sec = writer.sections.add( "" );
data_sec->set_type( SHT_PROGBITS );
data_sec->set_flags( SHF_ALLOC );
data_sec->set_addr_align( 1 );
data_sec->set_data( pseg->get_data(), pseg->get_file_size() );
data_seg->add_section_index( data_sec->get_index(), data_sec->get_addr_align() );
/* export each segment */
const char * data=pseg->get_data();
if (data != NULL)
{
std::string tmpFileName = tmp_path+"/segment";
char index = i+hash_offset+'0';
tmpFileName.append(&index,1);
saveDataToFile(tmpFileName, pseg->get_data(), pseg->get_file_size());
}
}
Elf_Half headerSize = writer.get_header_size() + writer.segments.size() * writer.get_segment_entry_size();
/* Create data section */
data_sec = writer.sections.add( "" );
data_sec->set_type( SHT_NOBITS );
data_sec->set_flags( SHF_ALLOC );
data_sec->set_addr_align( 1 );
char data[0x100]={0};
data_sec->set_data( data, headerSize );
/* Create a read/write segment */
header_seg->set_type( PT_NULL );
header_seg->set_virtual_address( 0 );
header_seg->set_physical_address( 0 );
header_seg->set_flags( 0 );
header_seg->set_align( 4 );
/* Add code section into program segment */
header_seg->add_section_index( data_sec->get_index(), data_sec->get_addr_align() );
/* set the entry point */
writer.set_entry(reader.get_entry());
/* Create ELF file */
writer.save(argv[2]);
/* Read ELF file header */
stream.open( argv[2], std::ios::in | std::ios::binary );
if ( !stream ) {
std::cout << "cant open tmp file" << std::endl;
return 1;
}
stream.seekg( 0 );
stream.read(elfHeader,headerSize);
stream.close();
/* export data to files */
std::string tmpheaderFileName = tmp_path+"/header";
saveDataToFile(tmpheaderFileName, elfHeader, headerSize);
std::string tmphashFileName = tmp_path+"/hash";
char empty[0x20];
saveDataToFile(tmphashFileName, empty, 0x20);
std::string tmphashSegrFileName = tmp_path+"/hashSeg";
saveDataToFile(tmphashSegrFileName, cert_chain, MAX_CERT_CHAIN_SIZE);
std::string tmpSiFileName = tmp_path+"/Si";
saveDataToFile(tmpSiFileName, Si, sizeof(Si));
std::string tmpSoFileName = tmp_path+"/So";
saveDataToFile(tmpSoFileName, So, sizeof(So));
std::string sectionSize = std::to_string(writer.get_section_entry_size());
std::string tmpSectionSizeFileName = tmp_path+"/sectionSize";
saveDataToFile(tmpSectionSizeFileName, sectionSize.c_str(), sizeof(sectionSize.c_str()));
return 0;
}
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