Files
sigmaker-ida/idasdk76/ldr/pe/common.cpp
2021-10-31 21:20:46 +02:00

702 lines
21 KiB
C++

#include <auto.hpp>
#include "common.h"
#include "../idaldr.h"
//------------------------------------------------------------------------
#ifdef LOADER_SOURCE // building a loader?
AS_PRINTF(1, 2) inline void pe_failure(const char *format, ...)
{
va_list va;
va_start(va, format);
qstring question("AUTOHIDE REGISTRY\n");
question.cat_vsprnt(format, va);
question.append("\nDo you wish to continue?");
if ( ask_yn(ASKBTN_YES, "%s", question.c_str()) != ASKBTN_YES )
{
loader_failure(NULL);
}
va_end(va);
}
#else
// for other purposes: just print the error message and continue
AS_PRINTF(1, 2) inline void pe_failure(const char *format, ...)
{
va_list va;
va_start(va, format);
qvprintf(format, va);
qprintf("\n");
va_end(va);
}
#endif
//------------------------------------------------------------------------
inline bool pe64_to_pe(peheader_t &pe, const peheader64_t &pe64, bool silent, bool zero_bad_data)
{
bool ok = true;
switch ( pe64.magic )
{
default:
if ( !silent )
{
ask_for_feedback("The input file has non-standard magic number (%x)",
pe64.magic);
}
ok = false;
/* no break */
case MAGIC_P32:
case MAGIC_ROM:
case 0:
memcpy(&pe, &pe64, sizeof(pe));
break;
case MAGIC_P32_PLUS:
// Copy the constant part
memcpy(&pe, &pe64, offsetof(peheader_t, stackres));
// Copy after the changed part
memcpy(&pe.loaderflags, &pe64.loaderflags,
sizeof(pe) - qoffsetof(peheader_t, loaderflags));
// Truncate the 64bit to 32bit
pe.stackres = low(pe64.stackres);
pe.stackcom = low(pe64.stackcom);
pe.heapres = low(pe64.heapres);
pe.heapcom = low(pe64.heapcom);
break;
}
// Do various checks
if ( !pe.is_efi()
&& (pe.objalign < pe.filealign
|| pe.filealign != 0 && (pe.filealign & (pe.filealign-1)) != 0 // check for power of 2
|| pe.objalign != 0 && (pe.objalign & (pe.objalign -1)) != 0) ) // check for power of 2
{
if ( !silent )
pe_failure("Invalid file: bad alignment value specified (section alignment: %08X, file alignment: %08X)", pe.objalign, pe.filealign);
}
if ( pe.imagesize > 0x77000000 || pe.imagesize < pe.allhdrsize )
{
if ( !silent )
pe_failure("Invalid file: bad ImageSize value %x", pe.imagesize);
}
if ( zero_bad_data )
{
if ( pe.nrvas != 0 && pe.nrvas < total_rvatab_count )
memset(&pe.expdir + pe.nrvas, 0, total_rvatab_size - pe.nrvas * sizeof(petab_t));
size_t fullhdrsize = pe.is_pe_plus() ? sizeof(pe64) : sizeof(pe);
size_t sectblstart = pe.first_section_pos(0);
// clear items covered by section table
if ( sectblstart < fullhdrsize
&& total_rvatab_size < fullhdrsize
&& sectblstart >= fullhdrsize - total_rvatab_size )
{
if ( !silent )
msg("Warning: image directories are covered by the section table, some entries will be ignored\n");
size_t clearcount = (fullhdrsize - sectblstart + sizeof(petab_t) -1 )/ sizeof(petab_t);
memset(&pe.expdir + (total_rvatab_count- clearcount), 0, clearcount * sizeof(petab_t));
}
}
return ok;
}
//------------------------------------------------------------------------
inline bool te_to_pe(peheader_t &pe, const teheader_t &te)
{
bool ok = true;
memset(&pe, 0, sizeof(pe));
pe.signature = te.signature;
pe.machine = te.machine;
pe.nobjs = te.nobjs;
pe.magic = pe.is_64bit_cpu() ? MAGIC_P32_PLUS : MAGIC_P32;
pe.entry = te.entry;
pe.text_start = te.text_start;
pe.allhdrsize = te.text_start + te.te_adjust();
if ( pe.is_pe_plus() )
pe.imagebase64 = te.imagebase64;
else
pe.imagebase32 = te.imagebase64;
pe.subsys = te.subsys;
pe.reltab = te.reltab;
pe.debdir = te.debdir;
pe.objalign = 1;
pe.filealign = 1;
return ok;
}
//------------------------------------------------------------------------
inline bool pe_loader_t::read_header(linput_t *li, off_t _peoff, bool silent, bool zero_bad_data)
{
peoff = _peoff;
qlseek(li, peoff);
memset(&pe64, 0, sizeof(pe64));
qlseek(li, peoff);
size_t size = qlread(li, &pe64, sizeof(pe64));
size_t minsize = pe64.magic == MAGIC_P32_PLUS
? qoffsetof(peheader64_t, subsys)
: qoffsetof(peheader_t, subsys);
bool ok = size > minsize
&& size <= sizeof(pe64)
&& (pe64.signature == PEEXE_ID || pe64.signature == BPEEXE_ID || pe64.signature == PLEXE_ID)
&& pe64_to_pe(pe, pe64, silent, zero_bad_data);
if ( ok )
{
// initialize imagebase for loading
set_imagebase((ea_t)pe.imagebase());
}
return ok;
}
//------------------------------------------------------------------------
inline bool pe_loader_t::read_header(linput_t *li, bool silent, bool zero_bad_data)
{
uint32 hdroff = 0;
link_ulink = false;
qlseek(li, hdroff);
if ( qlread(li, &exe, sizeof(exe)) != sizeof(exe) )
return false;
if ( exe.exe_ident != PEEXE_ID )
{
if ( exe.exe_ident == TEEXE_ID )
{
qlseek(li, hdroff);
if ( qlread(li, &te, sizeof(te)) != sizeof(te) )
return false;
bool ok = te_to_pe(pe, te);
if ( ok )
{
// initialize imagebase for loading
set_imagebase((ea_t)pe.imagebase());
peoff = hdroff;
}
return ok;
}
if ( exe.exe_ident == EXE_ID || exe.exe_ident == EXE_ID2 )
{
char tmp[8];
if ( qlread(li, tmp, sizeof(tmp)) == sizeof(tmp)
&& memcmp(tmp, "UniLink", 8) == 0 )
{
link_ulink = true;
}
qlseek(li, PE_PTROFF);
if ( qlread(li, &hdroff, sizeof(hdroff)) != sizeof(hdroff) )
return false;
}
}
return read_header(li, hdroff, silent, zero_bad_data);
}
//------------------------------------------------------------------------
inline bool pe_loader_t::vseek(linput_t *li, uint32 rva)
{
ea_t fpos = get_linput_type(li) == LINPUT_PROCMEM ? rva : map_ea(rva);
if ( fpos != BADADDR )
{
qlseek(li, fpos);
return true;
}
qlseek(li, rva, SEEK_SET);
return false;
}
//------------------------------------------------------------------------
inline char *pe_loader_t::asciiz(linput_t *li, uint32 rva, char *buf, size_t bufsize, bool *ok)
{
vseek(li, rva);
buf[0] = '\0';
char *ret = qlgetz(li, -1, buf, bufsize);
*ok = buf[0] != '\0';
return ret;
}
//------------------------------------------------------------------------
// same as asciiz() but don't set ok to false for successfully read empty strings
inline char *pe_loader_t::asciiz2(linput_t *li, uint32 rva, char *buf, size_t bufsize, bool *ok)
{
vseek(li, rva);
buf[0] = '\0';
// do not use qlgetz() here because we won't distinguish empty strings from read errors
ssize_t readsize = qlread(li, buf, bufsize-1);
if ( readsize < 0 || readsize >= bufsize )
*ok = false;
else
buf[readsize] = '\0';
return buf;
}
//------------------------------------------------------------------------
inline int pe_loader_t::process_sections(
linput_t *li,
off_t first_sec_pos,
int nobjs,
pe_section_visitor_t &psv)
{
transvec.qclear();
qvector<pesection_t> sec_headers;
// does the file layout match memory layout?
bool alt_align = pe.objalign == pe.filealign && pe.objalign < PAGE_SIZE;
qlseek(li, first_sec_pos);
validate_array_count(li, &nobjs, sizeof(pesection_t), "Number of sections", first_sec_pos);
for ( int i=0; i < nobjs; i++ )
{
pesection_t &sh = sec_headers.push_back();
if ( qlread(li, &sh, sizeof(sh)) != sizeof(sh) )
return -1;
if ( sh.s_vaddr != uint32(sh.s_scnptr) || sh.s_vsize > sh.s_psize )
alt_align = false;
}
if ( alt_align || pe.is_te() )
{
// according to Ivan Teblin from AVERT Labs, such files are
// mapped by Windows as-is and not section by section
// we mimic that behaviour
int code = psv.load_all();
if ( code != 0 )
return code;
}
int off_align = alt_align ? pe.filealign : FILEALIGN;
if ( pe.is_efi() || pe.is_te() )
off_align = 1;
uint32 max_va = 0;
for ( int i=0; i < nobjs; i++ )
{
pesection_t &sh = sec_headers[i];
uint32 scnptr = align_down(sh.s_scnptr, off_align);
transl_t &tr = transvec.push_back();
tr.start = sh.s_vaddr;
tr.psize = sh.get_psize(pe);
tr.end = pe.align_up_in_file(uint32(sh.s_vaddr + tr.psize));
tr.pos = scnptr;
if ( pe.is_te() )
tr.pos += te.te_adjust();
int code = psv.visit_section(sh, scnptr);
if ( code != 0 )
return code;
if ( max_va < sh.s_vaddr + sh.s_vsize )
max_va = sh.s_vaddr + sh.s_vsize;
}
if ( pe.is_te() )
pe.imagesize = max_va;
if ( nobjs == 0 || alt_align )
{
// add mapping for the header
transl_t tr;
tr.start = 0;
tr.psize = qlsize(li);
tr.end = pe.align_up_in_file(pe.imagesize);
tr.pos = 0;
// insert at the front so that it's always consulted last
transvec.insert(transvec.begin(), tr);
}
return 0;
}
//------------------------------------------------------------------------
inline int pe_loader_t::process_sections(linput_t *li, pe_section_visitor_t &psv)
{
off_t first_sec_pos = pe.is_te() ? te.first_section_pos(peoff) : pe.first_section_pos(peoff);
return process_sections(li, first_sec_pos, pe.nobjs, psv);
}
//------------------------------------------------------------------------
inline int pe_loader_t::process_sections(linput_t *li)
{
pe_section_visitor_t v;
return process_sections(li, v);
}
//-------------------------------------------------------------------------
inline void to_utf8(char *buf, size_t bufsz, bool force=false)
{
if ( force || !is_valid_utf8(buf) )
{
qstring qbuf;
if ( idb_utf8(&qbuf, buf) )
qstrncpy(buf, qbuf.c_str(), bufsz);
}
}
//------------------------------------------------------------------------
// process import table for one dll
inline int pe_loader_t::process_import_table(
linput_t *li,
ea_t atable,
ea_t ltable,
pe_import_visitor_t &piv)
{
bool is_pe_plus = pe.is_pe_plus();
uint32 elsize = piv.elsize = is_pe_plus ? 8 : 4;
const uint64 mask = is_pe_plus ? IMP_BY_ORD64 : IMP_BY_ORD32;
bool ok = true;
uint32 i;
for ( i=0; ok; i++, atable += elsize )
{
char buf[MAXSTR];
if ( !is_mul_ok(i, elsize) )
return 1;
uval_t rva_off = i * elsize;
if ( !is_add_ok(ltable, rva_off) )
return 1;
ea_t rva = ltable + rva_off;
if ( piv.withbase )
rva -= (uval_t)pe.imagebase();
uint32 fof = uint32(rva);
uint64 entry = is_pe_plus ? vaint64(li, fof, &ok) : valong(li, fof, &ok);
if ( entry == 0 )
break;
show_addr(atable);
int code;
if ( (entry & mask) == 0 ) // by name
{
ea_t nrva = (uval_t)entry + sizeof(short);
if ( piv.withbase )
nrva -= (uval_t)pe.imagebase();
fof = uint32(nrva);
asciiz2(li, fof, buf, sizeof(buf), &ok);
to_utf8(buf, sizeof(buf));
code = piv.visit_import(atable, entry, buf);
}
else
{
// ordinals are always 32bit, even in pe64
uint32 ord = entry & ~mask;
code = piv.visit_import(atable, ord, NULL);
}
if ( code != 0 )
return code;
}
return piv.leave_module(i);
}
//------------------------------------------------------------------------
// this function tries to read from a file as if it was reading from memory
// if translation not found for the given RVA then ZEROs are returned
// in addition, if it tries to read beyond a translation physical size
// the additional bytes will be returned as zeros
inline bool pe_loader_t::vmread(linput_t *li, uint32 rva, void *buf, size_t sz)
{
// clear whole user buffer
memset(buf, 0, sz);
size_t may_read = sz;
if ( get_linput_type(li) == LINPUT_PROCMEM )
{
qlseek(li, rva, SEEK_SET);
}
else
{
const transl_t *tr;
ea_t fpos = map_ea(rva, &tr);
// cannot find translation?
if ( fpos == BADADDR )
{
qlseek(li, int32(rva), SEEK_SET);
return true;
}
uint32 sectend = tr->pos + tr->psize; // section end
if ( fpos >= sectend )
return false; // data not present in the input file
qlseek(li, fpos);
// reading beyond section's limit?
uint32 after_read_pos = fpos + sz;
if ( after_read_pos < fpos )
return false; // integer overflow
if ( after_read_pos >= sectend )
{
// check if position belongs to the header and if reading beyond the limit
if ( uint32(fpos) < pe.allhdrsize && after_read_pos > pe.allhdrsize )
may_read = pe.allhdrsize - size_t(fpos);
else
may_read = sectend - fpos; // just read as much as section limit allows
}
}
QASSERT(20045, ssize_t(may_read) >= 0);
return qlread(li, buf, may_read) == (ssize_t)may_read;
}
//------------------------------------------------------------------------
// process all imports of a pe file
// returns: -1:could not read an impdir; 0-ok;
// other values can be returned by the visitor
inline int pe_loader_t::process_imports(linput_t *li, pe_import_visitor_t &piv)
{
if ( pe.impdir.rva == 0 )
return 0;
if ( transvec.empty() )
process_sections(li);
int code = 0;
for ( int ni=0; ; ni++ )
{
off_t off = pe.impdir.rva + ni*sizeof(peimpdir_t);
peimpdir_t &id = piv.id;
if ( !vmread(li, off, &id, sizeof(id)) )
{
memset(&id, 0, sizeof(id));
// we continue if the import descriptor is within the page belonging
// to the program
if ( map_ea(off) == BADADDR || map_ea(off+sizeof(id)-1) == BADADDR )
{
code = piv.impdesc_error(off);
if ( code != 0 )
break;
}
}
if ( id.dllname == 0 || id.looktab == 0 )
break;
ea_t ltable = id.table1; // OriginalFirstThunk
ea_t atable = id.looktab; // FirstThunk
bool ok = true;
char dll[MAXSTR];
asciiz(li, id.dllname, dll, sizeof(dll), &ok);
if ( !ok )
break;
to_utf8(dll, sizeof(dll), /*force=*/ true);
if ( map_ea(ltable) == BADADDR
|| ltable < pe.allhdrsize
|| pe.imagesize != 0 && ltable >= pe.imagesize )
{
ltable = atable;
}
atable += get_imagebase();
code = piv.visit_module(dll, atable, ltable);
if ( code != 0 )
break;
code = process_import_table(li, atable, ltable, piv);
if ( code != 0 )
break;
}
return code;
}
//------------------------------------------------------------------------
inline int pe_loader_t::process_delayed_imports(linput_t *li, pe_import_visitor_t &il)
{
if ( pe.didtab.rva == 0 )
return 0;
if ( transvec.empty() )
process_sections(li);
int code = 0;
uint32 ni = 0;
bool ok = true;
while ( true )
{
uint32 table = pe.didtab.rva + ni*uint32(sizeof(dimpdir_t));
if ( !vseek(li, table) )
break;
dimpdir_t &id = il.did;
if ( qlread(li, &id, sizeof(id)) != sizeof(id) )
return -1;
if ( !id.dllname )
break;
il.withbase = (id.attrs & DIMP_NOBASE) == 0;
uval_t base = il.withbase ? 0 : uval_t(get_imagebase());
ea_t atable = id.diat + base;
ea_t ltable = id.dint;
char dll[MAXSTR];
uint32 off = uint32(il.withbase ? id.dllname - (ea_t)pe.imagebase() : id.dllname);
asciiz(li, off, dll, sizeof(dll), &ok);
if ( !ok )
break;
to_utf8(dll, sizeof(dll), /*force=*/ true);
code = il.visit_module(dll, atable, ltable);
if ( code != 0 )
break;
code = process_import_table(li, atable, ltable, il);
if ( code != 0 )
break;
ni++;
}
return ok || code != 0 ? code : -1;
}
//------------------------------------------------------------------------
// process all exports of a pe file
// returns -2: could not read expdir, -1: other read errors, 0-ok,
// other values can be returned by the visitor
inline int pe_loader_t::process_exports(linput_t *li, pe_export_visitor_t &pev)
{
if ( pe.expdir.rva == 0 )
return 0;
if ( transvec.empty() )
process_sections(li);
if ( !vseek(li, pe.expdir.rva) )
return -2;
// process export directory
bool fok = true;
char buf[MAXSTR];
peexpdir_t ed;
if ( qlread(li, &ed, sizeof(ed)) != sizeof(ed) )
return -1;
asciiz2(li, ed.dllname, buf, sizeof(buf), &fok);
to_utf8(buf, sizeof(buf), /*force=*/ true);
int code = pev.visit_expdir(ed, buf);
if ( code != 0 )
return code;
// I'd like to have a better validation
uint64 maxsize = qlsize(li) + 4096;
if ( maxsize > pe.expdir.size && pe.expdir.size != 0 )
maxsize = pe.expdir.size;
validate_array_count(NULL, &ed.nnames, 6, "Number of exported names",
pe.expdir.rva, pe.expdir.rva+maxsize);
validate_array_count(NULL, &ed.naddrs, 4, "Number of exported addresses",
pe.expdir.rva, pe.expdir.rva+maxsize);
// gather name information
typedef std::map<int, qstring> names_t;
names_t names;
int rcode = fok ? 0 : -1;
for ( uint32 i=0; i < ed.nnames; i++ )
{
fok = true;
uint32 ordidx = vashort(li, ed.ordtab + i*sizeof(ushort), &fok);
if ( !fok )
{
if ( rcode == 0 )
rcode = -1;
continue;
}
ushort ord = ushort(ordidx + ed.ordbase);
uint32 rva = valong(li, ed.namtab + i*sizeof(uint32), &fok);
if ( !fok )
{
if ( rcode == 0 )
rcode = -1;
continue;
}
asciiz2(li, rva, buf, sizeof(buf), &fok);
if ( !fok )
{
if ( rcode == 0 )
rcode = -1;
continue;
}
to_utf8(buf, sizeof(buf));
names[ord] = buf;
}
// visit all exports
uint32 expdir_start_rva = pe.expdir.rva;
uint32 expdir_end_rva = pe.expdir.rva + maxsize;
for ( uint32 i = 0; i < ed.naddrs; i++ )
{
fok = true;
uint32 rva = valong(li, ed.adrtab + i*sizeof(uint32), &fok);
if ( rva != 0 && fok )
{
uint32 ord = i + ed.ordbase;
names_t::iterator p = names.find(ord);
const char *name = p != names.end() ? p->second.c_str() : "";
const char *forwarder = NULL;
if ( rva >= expdir_start_rva && rva < expdir_end_rva )
{
// string inside export directory: this is a forwarded export
asciiz(li, rva, buf, sizeof(buf), &fok);
if ( !fok )
{
if ( rcode == 0 )
rcode = -1;
continue;
}
char *dot = strrchr(buf, '.');
if ( dot != NULL )
{
char before_dot[MAXSTR];
char after_dot[MAXSTR];
*dot = '\0';
qstrncpy(before_dot, buf, sizeof(before_dot));
qstrncpy(after_dot, dot+1, sizeof(after_dot));
to_utf8(before_dot, sizeof(before_dot), /*force=*/ true);
to_utf8(after_dot, sizeof(after_dot), /*force=*/ false);
qsnprintf(buf, sizeof(buf), "%s.%s", before_dot, after_dot);
}
else
{
to_utf8(buf, sizeof(buf), /*force=*/ true);
}
forwarder = buf;
}
code = pev.visit_export(rva, ord, name, forwarder);
if ( code != 0 )
{
if ( rcode == 0 )
rcode = code;
}
}
else if ( !fok )
rcode = -1;
}
return rcode;
}
//------------------------------------------------------------------------
inline const char *get_pe_machine_name(uint16 machine)
{
switch ( machine )
{
case PECPU_80386: return "80386";
case PECPU_80486: return "80486";
case PECPU_80586: return "80586";
case PECPU_SH3: return "SH3";
case PECPU_SH3DSP: return "SH3DSP";
case PECPU_SH3E: return "SH3E";
case PECPU_SH4: return "SH4";
case PECPU_SH5: return "SH5";
case PECPU_ARM: return "ARM";
case PECPU_ARMI: return "ARMI";
case PECPU_ARMV7: return "ARMv7";
case PECPU_EPOC: return "ARM EPOC";
case PECPU_PPC: return "PPC";
case PECPU_PPCFP: return "PPC FP";
case PECPU_PPCBE: return "PPC BE";
case PECPU_IA64: return "IA64";
case PECPU_R3000: return "MIPS R3000";
case PECPU_R4000: return "MIPS R4000";
case PECPU_R6000: return "MIPS R6000";
case PECPU_R10000: return "MIPS R10000";
case PECPU_MIPS16: return "MIPS16";
case PECPU_WCEMIPSV2: return "MIPS WCEv2";
case PECPU_ALPHA: return "ALPHA";
case PECPU_ALPHA64: return "ALPHA 64";
case PECPU_AMD64: return "AMD64";
case PECPU_ARM64: return "ARM64";
case PECPU_M68K: return "M68K";
case PECPU_MIPSFPU: return "MIPS FPU";
case PECPU_MIPSFPU16: return "MIPS16 FPU";
case PECPU_EBC: return "EFI Bytecode";
case PECPU_AM33: return "AM33";
case PECPU_M32R: return "M32R";
case PECPU_CEF: return "CEF";
case PECPU_CEE: return "CEE";
case PECPU_TRICORE: return "TRICORE";
}
return NULL;
}
//-------------------------------------------------------------------------
inline bool pe_loader_t::read_strtable(qstring *out, linput_t *li)
{
bool ok = false;
if ( pe.symtof != 0 )
{
qoff64_t strtoff = qoff64_t(pe.symtof) + pe.nsyms * 18;
ok = read_string_table(out, li, strtoff);
}
return ok;
}