ddidderr/zstd-rs
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Fix ZSTD_f_zstd1_magicless for small data

Browse Source 
* Fix `ZSTD_FRAMEHEADERSIZE_PREFIX` and `ZSTD_FRAMEHEADERSIZE_MIN` to
  take a `format` parameter, so it is impossible to get the wrong size.
* Fix the places that called `ZSTD_FRAMEHEADERSIZE_PREFIX` without
  taking the format into account, which is now impossible by design.
* Call `ZSTD_frameHeaderSize_internal()` with `dctx->format`.
* The added tests catch both bugs in `ZSTD_decompressFrame()`.

Fixes #1813.
This commit is contained in:
Nick Terrell
2019-10-21 21:16:17 -07:00
parent 919d1d8e93
commit b1ec94e63c
6 changed files with 50 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files
lib/decompress/zstd_decompress.c
+12 -14
View File
@@ -88,10 +88,7 @@ size_t ZSTD_estimateDCtxSize(void) { return sizeof(ZSTD_DCtx); }
static size_t ZSTD_startingInputLength(ZSTD_format_e format)
{
size_t const startingInputLength = (format==ZSTD_f_zstd1_magicless) ?
ZSTD_FRAMEHEADERSIZE_PREFIX - ZSTD_FRAMEIDSIZE :
ZSTD_FRAMEHEADERSIZE_PREFIX;
ZSTD_STATIC_ASSERT(ZSTD_FRAMEHEADERSIZE_PREFIX >= ZSTD_FRAMEIDSIZE);
size_t const startingInputLength = ZSTD_FRAMEHEADERSIZE_PREFIX(format);
/* only supports formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless */
assert( (format == ZSTD_f_zstd1) || (format == ZSTD_f_zstd1_magicless) );
return startingInputLength;
@@ -376,7 +373,7 @@ unsigned long long ZSTD_findDecompressedSize(const void* src, size_t srcSize)
{
unsigned long long totalDstSize = 0;
while (srcSize >= ZSTD_FRAMEHEADERSIZE_PREFIX) {
while (srcSize >= ZSTD_startingInputLength(ZSTD_f_zstd1)) {
U32 const magicNumber = MEM_readLE32(src);
if ((magicNumber & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) {
@@ -629,11 +626,12 @@ static size_t ZSTD_decompressFrame(ZSTD_DCtx* dctx,
/* check */
RETURN_ERROR_IF(
remainingSrcSize < ZSTD_FRAMEHEADERSIZE_MIN+ZSTD_blockHeaderSize,
remainingSrcSize < ZSTD_FRAMEHEADERSIZE_MIN(dctx->format)+ZSTD_blockHeaderSize,
srcSize_wrong);
/* Frame Header */
{ size_t const frameHeaderSize = ZSTD_frameHeaderSize(ip, ZSTD_FRAMEHEADERSIZE_PREFIX);
{ size_t const frameHeaderSize = ZSTD_frameHeaderSize_internal(
ip, ZSTD_FRAMEHEADERSIZE_PREFIX(dctx->format), dctx->format);
if (ZSTD_isError(frameHeaderSize)) return frameHeaderSize;
RETURN_ERROR_IF(remainingSrcSize < frameHeaderSize+ZSTD_blockHeaderSize,
srcSize_wrong);
@@ -714,7 +712,7 @@ static size_t ZSTD_decompressMultiFrame(ZSTD_DCtx* dctx,
dictSize = ZSTD_DDict_dictSize(ddict);
}
while (srcSize >= ZSTD_FRAMEHEADERSIZE_PREFIX) {
while (srcSize >= ZSTD_startingInputLength(dctx->format)) {
#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
if (ZSTD_isLegacy(src, srcSize)) {
@@ -1300,14 +1298,14 @@ size_t ZSTD_DCtx_refPrefix(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSiz
/* ZSTD_initDStream_usingDict() :
* return : expected size, aka ZSTD_FRAMEHEADERSIZE_PREFIX.
* return : expected size, aka ZSTD_startingInputLength().
* this function cannot fail */
size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize)
{
DEBUGLOG(4, "ZSTD_initDStream_usingDict");
FORWARD_IF_ERROR( ZSTD_DCtx_reset(zds, ZSTD_reset_session_only) );
FORWARD_IF_ERROR( ZSTD_DCtx_loadDictionary(zds, dict, dictSize) );
return ZSTD_FRAMEHEADERSIZE_PREFIX;
return ZSTD_startingInputLength(zds->format);
}
/* note : this variant can't fail */
@@ -1324,16 +1322,16 @@ size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* dctx, const ZSTD_DDict* ddict)
{
FORWARD_IF_ERROR( ZSTD_DCtx_reset(dctx, ZSTD_reset_session_only) );
FORWARD_IF_ERROR( ZSTD_DCtx_refDDict(dctx, ddict) );
return ZSTD_FRAMEHEADERSIZE_PREFIX;
return ZSTD_startingInputLength(dctx->format);
}
/* ZSTD_resetDStream() :
* return : expected size, aka ZSTD_FRAMEHEADERSIZE_PREFIX.
* return : expected size, aka ZSTD_startingInputLength().
* this function cannot fail */
size_t ZSTD_resetDStream(ZSTD_DStream* dctx)
{
FORWARD_IF_ERROR(ZSTD_DCtx_reset(dctx, ZSTD_reset_session_only));
return ZSTD_FRAMEHEADERSIZE_PREFIX;
return ZSTD_startingInputLength(dctx->format);
}
@@ -1564,7 +1562,7 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB
zds->lhSize += remainingInput;
}
input->pos = input->size;
return (MAX(ZSTD_FRAMEHEADERSIZE_MIN, hSize) - zds->lhSize) + ZSTD_blockHeaderSize; /* remaining header bytes + next block header */
return (MAX((size_t)ZSTD_FRAMEHEADERSIZE_MIN(zds->format), hSize) - zds->lhSize) + ZSTD_blockHeaderSize; /* remaining header bytes + next block header */
}
assert(ip != NULL);
memcpy(zds->headerBuffer + zds->lhSize, ip, toLoad); zds->lhSize = hSize; ip += toLoad;