/* Public function to determine the linkage of an ELF. */
ElfType get_elf_linkage(const char *path)
{
ElfType ret = ELFERROR;
FILE *elf_file = NULL;
uint8_t pHeader[HEADERSIZE] = "";
elf_file = fopen(path, "r");
if (elf_file) {
if (fread(pHeader, 1, HEADERSIZE, elf_file) == HEADERSIZE) {
if (is_elf_magic(pHeader)) {
if ((pHeader[EI_DATA] == ELFDATA2LSB) &&
(pHeader[EI_CLASS] == ELFCLASS64)) {
/* 64 bit little endian */
ret = parseElf64(elf_file, pHeader, 1);
} else if ((pHeader[EI_DATA] == ELFDATA2MSB) &&
(pHeader[EI_CLASS] == ELFCLASS64)) {
/* 64 bit big endian */
ret = parseElf64(elf_file, pHeader, 0);
} else if ((pHeader[EI_DATA] == ELFDATA2LSB) &&
(pHeader[EI_CLASS] == ELFCLASS32)) {
/* 32 bit little endian */
ret = parseElf32(elf_file, pHeader, 1);
} else if ((pHeader[EI_DATA] == ELFDATA2MSB) &&
(pHeader[EI_CLASS] == ELFCLASS32)) {
/* 32 bit big endian */
ret = parseElf32(elf_file, pHeader, 0);
}
} else {
/*
* The binary is not an ELF. We assume it's a
* script. We should parse the #! line and
* check the interpreter to guard against
* static interpreters escaping the sandbox.
* As minijail is only called from rootfs
* it was deemed not necessary to check this.
* So we will just let execve decided if this
* is valid.
*/
ret = ELFDYNAMIC;
}
} else {
/*
* The file is smaller than |HEADERSIZE| bytes.
* We assume it's a short script. See above for
* reasoning on scripts.
*/
ret = ELFDYNAMIC;
}
fclose(elf_file);
}
return ret;
}
void parseElf(FILE* fp, long fileSize) {
// ELF Header
unsigned char* buffer = (unsigned char*)malloc(0x05);
fread(buffer, sizeof(unsigned char), 0x05, fp);
if (buffer[4] == 1) {
printf("Determined 32-bit.\n\n");
if (fseek(fp, 0l, SEEK_SET) != 0) {
printf("[ELF] Error seeking back to zero (parse).\n");
}
free(buffer);
parseElf32(fp, fileSize);
} else if (buffer[4] == 2) {
printf("Determined 64-bit.\n");
if (fseek(fp, 0l, SEEK_SET) != 0) {
printf("[ELF] Error seeking back to zero (parse).\n");
}
free(buffer);
parseElf64(fp, fileSize);
} else {
printf("Failed to determine 32-bit or 64-bit.\n");
return;
}
}
