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123 lines
6.3 KiB
C
123 lines
6.3 KiB
C
#ifndef LAIKA_BOX_H
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#define LAIKA_BOX_H
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#include "core/lmem.h"
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#include "core/lsodium.h"
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#include "core/lvm.h"
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#include "laika.h"
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#include <inttypes.h>
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#define LAIKA_BOX_SCRATCH_SIZE 128
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#define LAIKA_BOX_HEAPSIZE 256
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enum
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{
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LAIKA_BOX_UNLOCKED_INDX, /* for output */
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LAIKA_BOX_SCRATCH_INDX, /* for misc. scratch work the vm needs to do (hold keys, etc.) */
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LAIKA_BOX_DATA_INDX /* for input */
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};
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/* Laika Box:
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Laika Boxes are obfuscated storage mediums where data is only in memory for a very short
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amount of time. Of course, this can be bypassed with a simple debugger and setting a breakpoint
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right after the data is 'unlocked', but the game of obfuscation isn't to prevent the data from
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being seen, it's to slow the reverse engineer down.
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2 main APIs are exposed here, laikaB_unlock() & laikaB_lock(). Both of which are inlined to
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make it more painful for the reverse engineer to quickly dump boxes from memory, forcing them to
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set breakpoints across the executable. Each box has its own VM, with it's own deobfuscation
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routine. This makes static analysis a painful route for string dumping. These apis, while can be
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used directly, are abstracted through macros with the pre-built boxes.
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Use LAIKA_BOX_SKID_START & LAIKA_BOX_SKID_END for quick and dirty usage. The data macros in
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`lboxconfig.h` are passed to these, which are generated by VMBoxGen (`tools/vmboxgen`). This will
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be extended in the future with more boxes and such, however for the time being only
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LAIKA_BOX_SKID_* is implemented.
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*/
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struct sLaikaB_box
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{
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uint8_t unlockedData[LAIKA_BOX_HEAPSIZE];
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uint8_t scratch[LAIKA_BOX_SCRATCH_SIZE];
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uint8_t code[LAIKA_VM_CODESIZE];
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};
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/* ======================================[[ Box Var API ]]====================================== */
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#define LAIKA_BOX_STARTVAR(type, ident, box, data) \
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uint8_t __data##ident[LAIKA_VM_CODESIZE] = data; \
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type ident; \
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struct sLaikaB_box __box##ident = box; \
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laikaB_unlock(&__box##ident, __data##ident); \
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ident = (type)__box##ident.unlockedData;
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#define LAIKA_BOX_ENDVAR(ident) laikaB_lock(&__box##ident);
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#ifdef LAIKA_OBFUSCATE
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# define LAIKA_BOX_SKID_START(type, ident, strmacro) \
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LAIKA_BOX_STARTVAR(type, ident, LAIKA_BOX_SKID(KEY_##strmacro), DATA_##strmacro)
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# define LAIKA_BOX_SKID_END(ident) LAIKA_BOX_ENDVAR(ident)
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#else /* disable obfuscations */
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# define LAIKA_BOX_SKID_START(type, ident, strmacro) type ident = strmacro;
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# define LAIKA_BOX_SKID_END(ident) ((void)0) /* no-op */
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#endif
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/* ======================================[[ Laika Boxes ]]====================================== */
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/* BOX_SKID decodes null-terminated strings using a provided xor _key. aptly named lol */
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#define LAIKA_BOX_SKID(_key) \
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{ \
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.unlockedData = {0}, /* reserved */ \
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.code = { /* stack layout: \
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[0] - unlockedData (ptr) \
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[1] - data (ptr) \
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[2] - key (uint8_t) \
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[3] - working data (uint8_t) \
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*/ \
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LAIKA_MAKE_VM_IAB(OP_LOADCONST, 0, LAIKA_BOX_UNLOCKED_INDX), \
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LAIKA_MAKE_VM_IAB(OP_LOADCONST, 1, LAIKA_BOX_DATA_INDX), \
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LAIKA_MAKE_VM_IAB(OP_PUSHLIT, 2, _key), /* LOOP_START */ \
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LAIKA_MAKE_VM_IAB(OP_READ, 3, 1), /* load data into working data */ \
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LAIKA_MAKE_VM_IABC(OP_XOR, 3, 3, 2), /* xor data with key */ \
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LAIKA_MAKE_VM_IAB(OP_WRITE, 0, 3), /* write data to unlockedData */ \
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LAIKA_MAKE_VM_IA(OP_INCPTR, 0), \
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LAIKA_MAKE_VM_IA(OP_INCPTR, 1), \
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LAIKA_MAKE_VM_IAB(OP_TESTJMP, 3, -17), /* exit loop on null terminator */ \
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OP_EXIT \
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} \
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}
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/* ======================================[[ Raw Box API ]]====================================== */
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LAIKA_FORCEINLINE void *laikaB_unlock(struct sLaikaB_box *box, void *data)
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{
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struct sLaikaV_vm vm = {
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/* boxes have 2 reserved constants, [0] for the output, [1] for the input */
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.constList =
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{
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[LAIKA_BOX_UNLOCKED_INDX] = LAIKA_MAKE_VM_PTR(box->unlockedData),
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[LAIKA_BOX_SCRATCH_INDX] = LAIKA_MAKE_VM_PTR(box->scratch),
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[LAIKA_BOX_DATA_INDX] = LAIKA_MAKE_VM_PTR(data),
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},
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.code = { 0 },
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.stack = { 0 },
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.pc = 0
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};
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memcpy(vm.code, box->code, LAIKA_VM_CODESIZE);
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laikaV_execute(&vm);
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return (void *)box->unlockedData;
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}
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/* safely zeros the unlockedData using libsodium's api for clearing sensitive data from memory */
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LAIKA_FORCEINLINE void laikaB_lock(struct sLaikaB_box *box)
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{
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sodium_memzero(box->unlockedData, LAIKA_BOX_HEAPSIZE);
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sodium_memzero(box->scratch, LAIKA_BOX_SCRATCH_SIZE);
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}
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/* include KEY_* & DATA_* macros for each obfuscated string */
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#include "lboxconfig.h"
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#endif |