static int
lload(lua_State *L) {
struct reader rd;
rd.source = luaL_checklstring(L,1,&rd.source_sz);
const char * filename = luaL_checkstring(L, 2);
struct filter flt = { &rd.stream, inflateEnd, NULL, 0, 0 };
struct rc4_sbox sbox;
if (lua_isstring(L, 3)) {
size_t keysz;
const char * key = lua_tolstring(L, 3, &keysz);
if (keysz != 8) {
return luaL_error(L, "Only support 8 bytes key");
}
rc4_init(&sbox, (const uint8_t *)key);
rd.crypt_sbox = &sbox;
} else {
rd.crypt_sbox = NULL;
}
rd.flags = Z_NO_FLUSH;
z_stream *stream = &rd.stream;
stream->zalloc = Z_NULL;
stream->zfree = Z_NULL;
stream->opaque = Z_NULL;
stream->avail_in = 0;
stream->avail_out = 0;
int result = inflateInit(stream);
lz_assert(L, result, &flt);
result = lua_load (L, zip_reader, &rd, filename, "bt");
inflateEnd(stream);
if (result != LUA_OK) {
return lua_error(L);
}
return 1;
}
static const char *
zip_reader(lua_State *L, void *data, size_t *size) {
z_stream *stream;
struct reader *rd = data;
if (rd->source == NULL)
return NULL;
stream = &rd->stream;
if (stream->avail_in == 0 && rd->flags != Z_FINISH) {
if (rd->source_sz <= CHUNK_IN) {
rd->flags = Z_FINISH;
stream->avail_in = rd->source_sz;
} else {
stream->avail_in = CHUNK_IN;
}
if (rd->crypt_sbox) {
rc4_crypt(rd->crypt_sbox, (const uint8_t *)rd->source, rd->inbuffer, stream->avail_in);
stream->next_in = (z_const Bytef *)rd->inbuffer;
} else {
stream->next_in = (z_const Bytef *)rd->source;
}
rd->source += stream->avail_in;
rd->source_sz -= stream->avail_in;
}
stream->next_out = rd->outbuffer;
stream->avail_out = CHUNK_IN;
int result = inflate(stream, rd->flags);
struct filter flt = { &rd->stream, inflateEnd, NULL, 0, 0 };
lz_assert(L, result, &flt);
if (rd->flags == Z_FINISH && stream->avail_out != 0) {
rd->source = NULL;
}
*size = CHUNK_IN - stream->avail_out;
return (const char *)rd->outbuffer;
}
static int
ldecompress(lua_State *L) {
z_stream stream;
stream.zalloc = Z_NULL;
stream.zfree = Z_NULL;
stream.opaque = Z_NULL;
struct filter flt = {
&stream,
inflateEnd,
inflate,
CRYPT_NONE,
NULL,
};
struct rc4_sbox sbox;
if (lua_isstring(L, 2)) {
size_t keysz;
const char * key = lua_tolstring(L, 2, &keysz);
if (keysz != 8) {
return luaL_error(L, "Only support 8 bytes key");
}
rc4_init(&sbox, (const uint8_t *)key);
flt.crypt_type = CRYPT_IN;
flt.crypt_sbox = &sbox;
}
int result = inflateInit(&stream);
lz_assert(L, result, &flt);
return execute(L, &flt);
}
static int
execute(lua_State *L, struct filter *flt) {
z_stream *stream = flt->stream;
size_t avail_in;
const char * source = lua_tolstring(L, 1, &avail_in);
uint8_t chunk[CHUNK_IN];
int flags = Z_NO_FLUSH;
stream->avail_in = 0;
stream->avail_out = 0;
luaL_Buffer buff;
luaL_buffinit(L, &buff);
int result;
do {
if (stream->avail_in == 0 && flags != Z_FINISH) {
stream->next_in = (z_const Bytef *)chunk;
if (avail_in <= CHUNK_IN) {
flags = Z_FINISH;
stream->avail_in = avail_in;
} else {
stream->avail_in = CHUNK_IN;
}
if (flt->crypt_type == CRYPT_IN) {
rc4_crypt(flt->crypt_sbox, (const uint8_t *)source, chunk, stream->avail_in);
stream->next_in = (z_const Bytef *)chunk;
} else {
stream->next_in = (z_const Bytef *)source;
}
source += stream->avail_in;
avail_in -= stream->avail_in;
}
void *buffer = luaL_prepbuffer(&buff);
stream->next_out = buffer;
stream->avail_out = LUAL_BUFFERSIZE;
result = flt->execute(stream, flags);
lz_assert(L, result, flt);
if (flt->crypt_type == CRYPT_OUT) {
rc4_crypt(flt->crypt_sbox, buffer, buffer, LUAL_BUFFERSIZE - stream->avail_out);
}
luaL_addsize(&buff, LUAL_BUFFERSIZE - stream->avail_out);
} while ( result != Z_STREAM_END );
luaL_pushresult(&buff);
lua_pushinteger(L, stream->adler);
flt->end(stream);
return 2;
}
static int lz_deflate_new(lua_State *L) {
int level = luaL_optint(L, 1, Z_DEFAULT_COMPRESSION);
/* Allocate the stream: */
z_stream* stream = (z_stream*)lua_newuserdata(L, sizeof(z_stream));
stream->zalloc = Z_NULL;
stream->zfree = Z_NULL;
lz_assert(L, deflateInit(stream, level), stream, __FILE__, __LINE__);
/* Don't allow destructor to execute unless deflateInit was successful: */
luaL_getmetatable(L, "lz.deflate.meta");
lua_setmetatable(L, -2);
lua_pushnil(L);
lua_pushcclosure(L, lz_deflate, 2);
return 1;
}
static int lz_inflate_new(lua_State *L) {
/* Allocate the stream */
z_stream* stream = (z_stream*)lua_newuserdata(L, sizeof(z_stream));
/* By default, we will do gzip header detection w/ max window size */
int window_size = lua_isnumber(L, 1) ? lua_tointeger(L, 1) : MAX_WBITS + 32;
stream->zalloc = Z_NULL;
stream->zfree = Z_NULL;
stream->next_in = Z_NULL;
stream->avail_in = 0;
lz_assert(L, inflateInit2(stream, window_size), stream, __FILE__, __LINE__);
/* Don't allow destructor to execute unless deflateInit was successful: */
luaL_getmetatable(L, "lz.inflate.meta");
lua_setmetatable(L, -2);
lua_pushnil(L);
lua_pushcclosure(L, lz_inflate, 2);
return 1;
}
static int lz_deflate_new(lua_State *L) {
int level = luaL_optint(L, 1, Z_DEFAULT_COMPRESSION);
int window_size = luaL_optint(L, 2, MAX_WBITS);
/* Allocate the stream: */
z_stream* stream = (z_stream*)lua_newuserdata(L, sizeof(z_stream));
stream->zalloc = Z_NULL;
stream->zfree = Z_NULL;
int result = deflateInit2(stream, level, Z_DEFLATED, window_size,
DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY);
lz_assert(L, result, stream, __FILE__, __LINE__);
/* Don't allow destructor to execute unless deflateInit2 was successful: */
luaL_getmetatable(L, "lz.deflate.meta");
lua_setmetatable(L, -2);
lua_pushnil(L);
lua_pushcclosure(L, lz_deflate, 2);
return 1;
}
/**
* @upvalue z_stream - Memory for the z_stream.
* @upvalue remainder - Any remainder from the last deflate call.
*
* @param string - "print" to deflate stream.
* @param int - flush output buffer? Z_SYNC_FLUSH, Z_FULL_FLUSH, or Z_FINISH.
*
* if no params, terminates the stream (as if we got empty string and Z_FINISH).
*/
static int lz_filter_impl(lua_State *L, int (*filter)(z_streamp, int), int (*end)(z_streamp), char* name) {
int flush = Z_NO_FLUSH, result;
z_stream* stream;
luaL_Buffer buff;
size_t avail_in;
if ( filter == deflate ) {
const char *const opts[] = { "none", "sync", "full", "finish", NULL };
flush = luaL_checkoption(L, 2, opts[0], opts);
if ( flush ) flush++;
/* Z_NO_FLUSH(0) Z_SYNC_FLUSH(2), Z_FULL_FLUSH(3), Z_FINISH (4) */
/* No arguments or nil, we are terminating the stream: */
if ( lua_gettop(L) == 0 || lua_isnil(L, 1) ) {
flush = Z_FINISH;
}
}
stream = (z_stream*)lua_touserdata(L, lua_upvalueindex(1));
if ( stream == NULL ) {
if ( lua_gettop(L) >= 1 && lua_isstring(L, 1) ) {
lua_pushfstring(L, "IllegalState: calling %s function when stream was previously closed", name);
lua_error(L);
}
lua_pushstring(L, "");
lua_pushboolean(L, 1);
return 2; /* Ignore duplicate calls to "close". */
}
luaL_buffinit(L, &buff);
if ( lua_gettop(L) > 1 ) lua_pushvalue(L, 1);
if ( lua_isstring(L, lua_upvalueindex(2)) ) {
lua_pushvalue(L, lua_upvalueindex(2));
if ( lua_gettop(L) > 1 && lua_isstring(L, -2) ) {
lua_concat(L, 2);
}
}
/* Do the actual deflate'ing: */
stream->next_in = lua_gettop(L) > 0 ?
(unsigned char*)lua_tolstring(L, -1, &avail_in) :
NULL;
stream->avail_in = avail_in;
if ( ! stream->avail_in && ! flush ) {
/* Passed empty string, make it a noop instead of erroring out. */
lua_pushstring(L, "");
lua_pushboolean(L, 0);
lua_pushinteger(L, stream->total_in);
lua_pushinteger(L, stream->total_out);
return 4;
}
do {
stream->next_out = (unsigned char*)luaL_prepbuffer(&buff);
stream->avail_out = LUAL_BUFFERSIZE;
result = filter(stream, flush);
if ( Z_BUF_ERROR != result ) {
/* Ignore Z_BUF_ERROR since that just indicates that we
* need a larger buffer in order to proceed. Thanks to
* Tobias Markmann for finding this bug!
*/
lz_assert(L, result, stream, __FILE__, __LINE__);
}
luaL_addsize(&buff, LUAL_BUFFERSIZE - stream->avail_out);
} while ( stream->avail_out == 0 );
/* Need to do this before we alter the stack: */
luaL_pushresult(&buff);
/* Save remainder in lua_upvalueindex(2): */
if ( NULL != stream->next_in ) {
lua_pushlstring(L, (char*)stream->next_in, stream->avail_in);
lua_replace(L, lua_upvalueindex(2));
}
/* "close" the stream/remove finalizer: */
if ( result == Z_STREAM_END ) {
/* Clear-out the metatable so end is not called twice: */
lua_pushnil(L);
lua_setmetatable(L, lua_upvalueindex(1));
/* nil the upvalue: */
lua_pushnil(L);
lua_replace(L, lua_upvalueindex(1));
/* Close the stream: */
lz_assert(L, end(stream), stream, __FILE__, __LINE__);
lua_pushboolean(L, 1);
} else {
lua_pushboolean(L, 0);
}
lua_pushinteger(L, stream->total_in);
lua_pushinteger(L, stream->total_out);
return 4;
}
