lua/lstate.c
author Ryan C. Gordon <icculus@icculus.org>
Fri, 23 Jun 2017 17:28:03 -0400
changeset 58 1390348facc7
parent 0 d7ee4e2ed49d
permissions -rw-r--r--
Command line tool that decrypts an OPVault keychain and dumps it to stdout.

To compile: gcc -o opvault opvault.c cJSON.c -lcrypto

Usage: ./opvault </path/to/mykeychain.opvault> <password>

This is just a proof of concept; I'll be recycling this into proper OPVault
support in 1pass later and deleting this tool.

This uses OpenSSL's libcrypto for the math instead of all the homegrown
crypto this project is otherwise using. I'll probably migrate the rest in
this direction, too, since this wasn't as bad as I expected to use and
gets you all the package-manager mojo of automatic bug fixes and security
patches and shared code, etc.

cJSON parses JSON in C. That is from https://github.com/DaveGamble/cJSON

An example OPVault keychain from AgileBits is available here:

https://cache.agilebits.com/security-kb/
/*
** $Id: lstate.c,v 2.99.1.2 2013/11/08 17:45:31 roberto Exp $
** Global State
** See Copyright Notice in lua.h
*/


#include <stddef.h>
#include <string.h>

#define lstate_c
#define LUA_CORE

#include "lua.h"

#include "lapi.h"
#include "ldebug.h"
#include "ldo.h"
#include "lfunc.h"
#include "lgc.h"
#include "llex.h"
#include "lmem.h"
#include "lstate.h"
#include "lstring.h"
#include "ltable.h"
#include "ltm.h"


#if !defined(LUAI_GCPAUSE)
#define LUAI_GCPAUSE	200  /* 200% */
#endif

#if !defined(LUAI_GCMAJOR)
#define LUAI_GCMAJOR	200  /* 200% */
#endif

#if !defined(LUAI_GCMUL)
#define LUAI_GCMUL	200 /* GC runs 'twice the speed' of memory allocation */
#endif


#define MEMERRMSG	"not enough memory"


/*
** a macro to help the creation of a unique random seed when a state is
** created; the seed is used to randomize hashes.
*/
#if !defined(luai_makeseed)
#include <time.h>
#define luai_makeseed()		cast(unsigned int, time(NULL))
#endif



/*
** thread state + extra space
*/
typedef struct LX {
#if defined(LUAI_EXTRASPACE)
  char buff[LUAI_EXTRASPACE];
#endif
  lua_State l;
} LX;


/*
** Main thread combines a thread state and the global state
*/
typedef struct LG {
  LX l;
  global_State g;
} LG;



#define fromstate(L)	(cast(LX *, cast(lu_byte *, (L)) - offsetof(LX, l)))


/*
** Compute an initial seed as random as possible. In ANSI, rely on
** Address Space Layout Randomization (if present) to increase
** randomness..
*/
#define addbuff(b,p,e) \
  { size_t t = cast(size_t, e); \
    memcpy(buff + p, &t, sizeof(t)); p += sizeof(t); }

static unsigned int makeseed (lua_State *L) {
  char buff[4 * sizeof(size_t)];
  unsigned int h = luai_makeseed();
  int p = 0;
  addbuff(buff, p, L);  /* heap variable */
  addbuff(buff, p, &h);  /* local variable */
  addbuff(buff, p, luaO_nilobject);  /* global variable */
  addbuff(buff, p, &lua_newstate);  /* public function */
  lua_assert(p == sizeof(buff));
  return luaS_hash(buff, p, h);
}


/*
** set GCdebt to a new value keeping the value (totalbytes + GCdebt)
** invariant
*/
void luaE_setdebt (global_State *g, l_mem debt) {
  g->totalbytes -= (debt - g->GCdebt);
  g->GCdebt = debt;
}


CallInfo *luaE_extendCI (lua_State *L) {
  CallInfo *ci = luaM_new(L, CallInfo);
  lua_assert(L->ci->next == NULL);
  L->ci->next = ci;
  ci->previous = L->ci;
  ci->next = NULL;
  return ci;
}


void luaE_freeCI (lua_State *L) {
  CallInfo *ci = L->ci;
  CallInfo *next = ci->next;
  ci->next = NULL;
  while ((ci = next) != NULL) {
    next = ci->next;
    luaM_free(L, ci);
  }
}


static void stack_init (lua_State *L1, lua_State *L) {
  int i; CallInfo *ci;
  /* initialize stack array */
  L1->stack = luaM_newvector(L, BASIC_STACK_SIZE, TValue);
  L1->stacksize = BASIC_STACK_SIZE;
  for (i = 0; i < BASIC_STACK_SIZE; i++)
    setnilvalue(L1->stack + i);  /* erase new stack */
  L1->top = L1->stack;
  L1->stack_last = L1->stack + L1->stacksize - EXTRA_STACK;
  /* initialize first ci */
  ci = &L1->base_ci;
  ci->next = ci->previous = NULL;
  ci->callstatus = 0;
  ci->func = L1->top;
  setnilvalue(L1->top++);  /* 'function' entry for this 'ci' */
  ci->top = L1->top + LUA_MINSTACK;
  L1->ci = ci;
}


static void freestack (lua_State *L) {
  if (L->stack == NULL)
    return;  /* stack not completely built yet */
  L->ci = &L->base_ci;  /* free the entire 'ci' list */
  luaE_freeCI(L);
  luaM_freearray(L, L->stack, L->stacksize);  /* free stack array */
}


/*
** Create registry table and its predefined values
*/
static void init_registry (lua_State *L, global_State *g) {
  TValue mt;
  /* create registry */
  Table *registry = luaH_new(L);
  sethvalue(L, &g->l_registry, registry);
  luaH_resize(L, registry, LUA_RIDX_LAST, 0);
  /* registry[LUA_RIDX_MAINTHREAD] = L */
  setthvalue(L, &mt, L);
  luaH_setint(L, registry, LUA_RIDX_MAINTHREAD, &mt);
  /* registry[LUA_RIDX_GLOBALS] = table of globals */
  sethvalue(L, &mt, luaH_new(L));
  luaH_setint(L, registry, LUA_RIDX_GLOBALS, &mt);
}


/*
** open parts of the state that may cause memory-allocation errors
*/
static void f_luaopen (lua_State *L, void *ud) {
  global_State *g = G(L);
  UNUSED(ud);
  stack_init(L, L);  /* init stack */
  init_registry(L, g);
  luaS_resize(L, MINSTRTABSIZE);  /* initial size of string table */
  luaT_init(L);
  luaX_init(L);
  /* pre-create memory-error message */
  g->memerrmsg = luaS_newliteral(L, MEMERRMSG);
  luaS_fix(g->memerrmsg);  /* it should never be collected */
  g->gcrunning = 1;  /* allow gc */
  g->version = lua_version(NULL);
  luai_userstateopen(L);
}


/*
** preinitialize a state with consistent values without allocating
** any memory (to avoid errors)
*/
static void preinit_state (lua_State *L, global_State *g) {
  G(L) = g;
  L->stack = NULL;
  L->ci = NULL;
  L->stacksize = 0;
  L->errorJmp = NULL;
  L->nCcalls = 0;
  L->hook = NULL;
  L->hookmask = 0;
  L->basehookcount = 0;
  L->allowhook = 1;
  resethookcount(L);
  L->openupval = NULL;
  L->nny = 1;
  L->status = LUA_OK;
  L->errfunc = 0;
}


static void close_state (lua_State *L) {
  global_State *g = G(L);
  luaF_close(L, L->stack);  /* close all upvalues for this thread */
  luaC_freeallobjects(L);  /* collect all objects */
  if (g->version)  /* closing a fully built state? */
    luai_userstateclose(L);
  luaM_freearray(L, G(L)->strt.hash, G(L)->strt.size);
  luaZ_freebuffer(L, &g->buff);
  freestack(L);
  lua_assert(gettotalbytes(g) == sizeof(LG));
  (*g->frealloc)(g->ud, fromstate(L), sizeof(LG), 0);  /* free main block */
}


LUA_API lua_State *lua_newthread (lua_State *L) {
  lua_State *L1;
  lua_lock(L);
  luaC_checkGC(L);
  L1 = &luaC_newobj(L, LUA_TTHREAD, sizeof(LX), NULL, offsetof(LX, l))->th;
  setthvalue(L, L->top, L1);
  api_incr_top(L);
  preinit_state(L1, G(L));
  L1->hookmask = L->hookmask;
  L1->basehookcount = L->basehookcount;
  L1->hook = L->hook;
  resethookcount(L1);
  luai_userstatethread(L, L1);
  stack_init(L1, L);  /* init stack */
  lua_unlock(L);
  return L1;
}


void luaE_freethread (lua_State *L, lua_State *L1) {
  LX *l = fromstate(L1);
  luaF_close(L1, L1->stack);  /* close all upvalues for this thread */
  lua_assert(L1->openupval == NULL);
  luai_userstatefree(L, L1);
  freestack(L1);
  luaM_free(L, l);
}


LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
  int i;
  lua_State *L;
  global_State *g;
  LG *l = cast(LG *, (*f)(ud, NULL, LUA_TTHREAD, sizeof(LG)));
  if (l == NULL) return NULL;
  L = &l->l.l;
  g = &l->g;
  L->next = NULL;
  L->tt = LUA_TTHREAD;
  g->currentwhite = bit2mask(WHITE0BIT, FIXEDBIT);
  L->marked = luaC_white(g);
  g->gckind = KGC_NORMAL;
  preinit_state(L, g);
  g->frealloc = f;
  g->ud = ud;
  g->mainthread = L;
  g->seed = makeseed(L);
  g->uvhead.u.l.prev = &g->uvhead;
  g->uvhead.u.l.next = &g->uvhead;
  g->gcrunning = 0;  /* no GC while building state */
  g->GCestimate = 0;
  g->strt.size = 0;
  g->strt.nuse = 0;
  g->strt.hash = NULL;
  setnilvalue(&g->l_registry);
  luaZ_initbuffer(L, &g->buff);
  g->panic = NULL;
  g->version = NULL;
  g->gcstate = GCSpause;
  g->allgc = NULL;
  g->finobj = NULL;
  g->tobefnz = NULL;
  g->sweepgc = g->sweepfin = NULL;
  g->gray = g->grayagain = NULL;
  g->weak = g->ephemeron = g->allweak = NULL;
  g->totalbytes = sizeof(LG);
  g->GCdebt = 0;
  g->gcpause = LUAI_GCPAUSE;
  g->gcmajorinc = LUAI_GCMAJOR;
  g->gcstepmul = LUAI_GCMUL;
  for (i=0; i < LUA_NUMTAGS; i++) g->mt[i] = NULL;
  if (luaD_rawrunprotected(L, f_luaopen, NULL) != LUA_OK) {
    /* memory allocation error: free partial state */
    close_state(L);
    L = NULL;
  }
  return L;
}


LUA_API void lua_close (lua_State *L) {
  L = G(L)->mainthread;  /* only the main thread can be closed */
  lua_lock(L);
  close_state(L);
}