//-------------------------------------------------------------------------- static bool find_impdir(area_t *impdir) { impdir->startEA = impdir->endEA = 0; uint32 ea32 = uint32(an_imported_func); for ( ea_t pos = curmod.startEA; pos <= curmod.endEA && (pos = bin_search(pos, curmod.endEA, (uchar *)&ea32, NULL, 4, BIN_SEARCH_FORWARD, BIN_SEARCH_NOBREAK|BIN_SEARCH_CASE)) != BADADDR; pos += sizeof(DWORD) ) { // skip unaligned matches if ( (pos & 3) != 0 ) continue; // cool, we found a pointer to an imported function // now try to determine the impdir bounds ea_t bounds[2] = {pos, pos}; for ( int k=0; k < 2; k++ ) { ea_t ea = pos; while ( true ) { if ( k == 1 ) ea += ptrSz; else ea -= ptrSz; ea_t func = is_9x ? win9x_find_thunk(ea) : getPtr(ea); if ( func == 0 ) continue; if ( !isEnabled(func) ) break; if ( curmod.contains(func) ) break; module_info_t mi; if ( !find_module(func, &mi) ) break; bounds[k] = ea; } } bounds[1] += ptrSz; asize_t bsize = bounds[1] - bounds[0]; if ( bsize > impdir->size() ) *impdir = area_t(bounds[0], bounds[1]); } return impdir->startEA != 0; }
//-------------------------------------------------------------------------- // WinCE device seems to freeze and require a hard reset if a bpt is // set at coredll (and other system areas?) // we never write there bool win32_debmod_t::may_write(ea_t ea) { static area_t forbidden_area; if ( forbidden_area.startEA == 0 ) { wince_module_t coredll; find_module_by_name("coredll", &coredll); common_e32_lite &e32 = get_e32(&coredll); forbidden_area.startEA = e32.vbase; forbidden_area.endEA = e32.vbase + e32.vsize; } if ( ea >= 0x80000000 || forbidden_area.contains(ea) ) { SetLastError(ERROR_ACCESS_DENIED); return false; } return true; }
//-------------------------------------------------------------------------- static int idaapi callback( void * /*user_data*/, int notification_code, va_list va) { static int stage = 0; static bool is_dll; static char needed_file[QMAXPATH]; switch ( notification_code ) { case dbg_process_start: case dbg_process_attach: get_input_file_path(needed_file, sizeof(needed_file)); // no break case dbg_library_load: if ( stage == 0 ) { const debug_event_t *pev = va_arg(va, const debug_event_t *); if ( !strieq(pev->modinfo.name, needed_file) ) break; if ( notification_code == dbg_library_load ) is_dll = true; // remember the current module bounds if ( pev->modinfo.rebase_to != BADADDR ) curmod.startEA = pev->modinfo.rebase_to; else curmod.startEA = pev->modinfo.base; curmod.endEA = curmod.startEA + pev->modinfo.size; deb(IDA_DEBUG_PLUGIN, "UUNP: module space %a-%a\n", curmod.startEA, curmod.endEA); ++stage; } break; case dbg_library_unload: if ( stage != 0 && is_dll ) { const debug_event_t *pev = va_arg(va, const debug_event_t *); if ( curmod.startEA == pev->modinfo.base || curmod.startEA == pev->modinfo.rebase_to ) { deb(IDA_DEBUG_PLUGIN, "UUNP: unload unpacked module\n"); if ( stage > 2 ) enable_step_trace(false); stage = 0; curmod.startEA = 0; curmod.endEA = 0; _hide_wait_box(); } } break; case dbg_run_to: // Parameters: const debug_event_t *event dbg->stopped_at_debug_event(true); bp_gpa = get_name_ea(BADADDR, "kernel32_GetProcAddress"); #ifndef __X64__ if( (LONG)GetVersion() < 0 ) // win9x mode -- use thunk's { is_9x = true; win9x_resolve_gpa_thunk(); } #endif if ( bp_gpa == BADADDR ) { bring_debugger_to_front(); warning("Sorry, could not find kernel32.GetProcAddress"); FORCE_STOP: stage = 4; // last stage clear_requests_queue(); request_exit_process(); run_requests(); break; } else if( !my_add_bpt(bp_gpa) ) { bring_debugger_to_front(); warning("Sorry, can not set bpt to kernel32.GetProcAddress"); goto FORCE_STOP; } else { ++stage; set_wait_box("Waiting for a call to GetProcAddress()"); } continue_process(); break; case dbg_bpt: // A user defined breakpoint was reached. // Parameters: thid_t tid // ea_t breakpoint_ea // int *warn = -1 // Return (in *warn): // -1 - to display a breakpoint warning dialog // if the process is suspended. // 0 - to never display a breakpoint warning dialog. // 1 - to always display a breakpoint warning dialog. { thid_t tid = va_arg(va, thid_t); qnotused(tid); ea_t ea = va_arg(va, ea_t); //int *warn = va_arg(va, int*); if ( stage == 2 ) { if ( ea == bp_gpa ) { regval_t rv; if ( get_reg_val(REGNAME_ESP, &rv) ) { ea_t esp = ea_t(rv.ival); invalidate_dbgmem_contents(esp, 1024); ea_t gpa_caller = getPtr(esp); if ( !is_library_entry(gpa_caller) ) { ea_t nameaddr; if ( ptrSz == 4 ) { nameaddr = get_long(esp+8); } else { get_reg_val(REGNAME_ECX, &rv); nameaddr = ea_t(rv.ival); } invalidate_dbgmem_contents(nameaddr, 1024); char name[MAXSTR]; size_t len = get_max_ascii_length(nameaddr, ASCSTR_C, ALOPT_IGNHEADS); name[0] = '\0'; get_ascii_contents2(nameaddr, len, ASCSTR_C, name, sizeof(name)); if ( !ignore_win32_api(name) ) { deb(IDA_DEBUG_PLUGIN, "%a: found a call to GetProcAddress(%s)\n", gpa_caller, name); if ( !my_del_bpt(bp_gpa) || !my_add_bpt(gpa_caller) ) error("Can not modify breakpoint"); } } } } else if ( ea == bpt_ea ) { my_del_bpt(ea); if ( !is_library_entry(ea) ) { msg("Uunp: reached unpacker code at %a, switching to trace mode\n", ea); enable_step_trace(true); ++stage; uint64 eax; if ( get_reg_val(REGNAME_EAX, &eax) ) an_imported_func = ea_t(eax); set_wait_box("Waiting for the unpacker to finish"); } else { warning("%a: bpt in library code", ea); // how can it be? my_add_bpt(bp_gpa); } } // not our bpt? skip it else { // hide the wait box to allow others plugins to properly stop _hide_wait_box(); break; } } } // while continue_process() would work here too, request+run is more universal // because they do not ignore the request queue request_continue_process(); run_requests(); break; case dbg_trace: // A step occured (one instruction was executed). This event // notification is only generated if step tracing is enabled. // Parameter: none if ( stage == 3 ) { thid_t tid = va_arg(va, thid_t); qnotused(tid); ea_t ip = va_arg(va, ea_t); // ip reached the OEP range? if ( oep_area.contains(ip) ) { // stop the trace mode enable_step_trace(false); msg("Uunp: reached OEP %a\n", ip); set_wait_box("Reanalyzing the unpacked code"); // reanalyze the unpacked code do_unknown_range(oep_area.startEA, oep_area.size(), DOUNK_EXPAND); auto_make_code(ip); // plan to make code noUsed(oep_area.startEA, oep_area.endEA); // plan to reanalyze auto_mark_range(oep_area.startEA, oep_area.endEA, AU_FINAL); // plan to analyze move_entry(ip); // mark the program's entry point _hide_wait_box(); // inform the user bring_debugger_to_front(); if ( askyn_c(1, "HIDECANCEL\n" "The universal unpacker has finished its work.\n" "Do you want to take a memory snapshot and stop now?\n" "(you can do it yourself if you want)\n") > 0 ) { set_wait_box("Recreating the import table"); invalidate_dbgmem_config(); if ( is_9x ) find_thunked_imports(); create_impdir(); set_wait_box("Storing resources to 'resource.res'"); if ( resfile[0] != '\0' ) extract_resource(resfile); _hide_wait_box(); if ( take_memory_snapshot(true) ) goto FORCE_STOP; } suspend_process(); unhook_from_notification_point(HT_DBG, callback, NULL); } } break; case dbg_process_exit: { stage = 0; // stop the tracing _hide_wait_box(); unhook_from_notification_point(HT_DBG, callback, NULL); if ( success ) jumpto(inf.beginEA, -1); else tell_about_failure(); } break; case dbg_exception:// Parameters: const debug_event_t *event // int *warn = -1 // Return (in *warn): // -1 - to display an exception warning dialog // if the process is suspended. // 0 - to never display an exception warning dialog. // 1 - to always display an exception warning dialog. { // const debug_event_t *event = va_arg(va, const debug_event_t *); // int *warn = va_arg(va, int *); // FIXME: handle code which uses SEH to unpack itself if ( askyn_c(1, "AUTOHIDE DATABASE\n" "HIDECANCEL\n" "An exception occurred in the program.\n" "UUNP does not support exceptions yet.\n" "The execution has been suspended.\n" "Do you want to continue the unpacking?") <= 0 ) { _hide_wait_box(); stage = 0; enable_step_trace(false); // stop the trace mode suspend_process(); } else { continue_process(); } } break; case dbg_request_error: // An error occured during the processing of a request. // Parameters: ui_notification_t failed_command // dbg_notification_t failed_dbg_notification { ui_notification_t failed_cmd = va_arg(va, ui_notification_t); dbg_notification_t failed_dbg_notification = va_arg(va, dbg_notification_t); _hide_wait_box(); stage = 0; warning("dbg request error: command: %d notification: %d", failed_cmd, failed_dbg_notification); } break; } return 0; }
//-------------------------------------------------------------------------- inline bool is_library_entry(ea_t ea) { return !curmod.contains(ea); }