From: Yann Collet <yann.collet.73@gmail.com>
Date: Wed, 15 Jun 2016 16:48:51 +0000 (+0200)
Subject: strengthened dict loading on decompresson side
X-Git-Tag: v0.7.0^2~11
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=736d419289591260f51a515b9e46384d8cc99322;p=thirdparty%2Fzstd.git

strengthened dict loading on decompresson side
---

diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index b1edaff3b..1ae321838 100644
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -2335,17 +2335,21 @@ static size_t ZSTD_loadDictionaryContent(ZSTD_CCtx* zc, const void* src, size_t
 /* Dictionary format :
      Magic == ZSTD_DICT_MAGIC (4 bytes)
      HUF_writeCTable(256)
+     FSE_writeNCount(ml)
+     FSE_writeNCount(off)
+     FSE_writeNCount(ll)
+     RepOffsets
      Dictionary content
 */
 /*! ZSTD_loadDictEntropyStats() :
-    @return : size read from dictionary */
-static size_t ZSTD_loadDictEntropyStats(ZSTD_CCtx* zc, const void* dict, size_t dictSize)
+    @return : size read from dictionary
+    note : magic number supposed already checked */
+static size_t ZSTD_loadDictEntropyStats(ZSTD_CCtx* cctx, const void* dict, size_t dictSize)
 {
-    /* note : magic number already checked */
     const BYTE* dictPtr = (const BYTE*)dict;
     const BYTE* const dictEnd = dictPtr + dictSize;
 
-    {   size_t const hufHeaderSize = HUF_readCTable(zc->hufTable, 255, dict, dictSize);
+    {   size_t const hufHeaderSize = HUF_readCTable(cctx->hufTable, 255, dict, dictSize);
         if (HUF_isError(hufHeaderSize)) return ERROR(dictionary_corrupted);
         dictPtr += hufHeaderSize;
     }
@@ -2354,7 +2358,7 @@ static size_t ZSTD_loadDictEntropyStats(ZSTD_CCtx* zc, const void* dict, size_t
         unsigned offcodeMaxValue = MaxOff, offcodeLog = OffFSELog;
         size_t const offcodeHeaderSize = FSE_readNCount(offcodeNCount, &offcodeMaxValue, &offcodeLog, dictPtr, dictEnd-dictPtr);
         if (FSE_isError(offcodeHeaderSize)) return ERROR(dictionary_corrupted);
-        { size_t const errorCode = FSE_buildCTable(zc->offcodeCTable, offcodeNCount, offcodeMaxValue, offcodeLog);
+        { size_t const errorCode = FSE_buildCTable(cctx->offcodeCTable, offcodeNCount, offcodeMaxValue, offcodeLog);
           if (FSE_isError(errorCode)) return ERROR(dictionary_corrupted); }
         dictPtr += offcodeHeaderSize;
     }
@@ -2363,7 +2367,7 @@ static size_t ZSTD_loadDictEntropyStats(ZSTD_CCtx* zc, const void* dict, size_t
         unsigned matchlengthMaxValue = MaxML, matchlengthLog = MLFSELog;
         size_t const matchlengthHeaderSize = FSE_readNCount(matchlengthNCount, &matchlengthMaxValue, &matchlengthLog, dictPtr, dictEnd-dictPtr);
         if (FSE_isError(matchlengthHeaderSize)) return ERROR(dictionary_corrupted);
-        { size_t const errorCode = FSE_buildCTable(zc->matchlengthCTable, matchlengthNCount, matchlengthMaxValue, matchlengthLog);
+        { size_t const errorCode = FSE_buildCTable(cctx->matchlengthCTable, matchlengthNCount, matchlengthMaxValue, matchlengthLog);
           if (FSE_isError(errorCode)) return ERROR(dictionary_corrupted); }
         dictPtr += matchlengthHeaderSize;
     }
@@ -2372,18 +2376,18 @@ static size_t ZSTD_loadDictEntropyStats(ZSTD_CCtx* zc, const void* dict, size_t
         unsigned litlengthMaxValue = MaxLL, litlengthLog = LLFSELog;
         size_t const litlengthHeaderSize = FSE_readNCount(litlengthNCount, &litlengthMaxValue, &litlengthLog, dictPtr, dictEnd-dictPtr);
         if (FSE_isError(litlengthHeaderSize)) return ERROR(dictionary_corrupted);
-        { size_t const errorCode = FSE_buildCTable(zc->litlengthCTable, litlengthNCount, litlengthMaxValue, litlengthLog);
+        { size_t const errorCode = FSE_buildCTable(cctx->litlengthCTable, litlengthNCount, litlengthMaxValue, litlengthLog);
           if (FSE_isError(errorCode)) return ERROR(dictionary_corrupted); }
         dictPtr += litlengthHeaderSize;
     }
 
     if (dictPtr+12 > dictEnd) return ERROR(dictionary_corrupted);
-    zc->rep[0] = MEM_readLE32(dictPtr+0); if (zc->rep[0] >= dictSize) return ERROR(dictionary_corrupted);
-    zc->rep[1] = MEM_readLE32(dictPtr+4); if (zc->rep[1] >= dictSize) return ERROR(dictionary_corrupted);
-    zc->rep[2] = MEM_readLE32(dictPtr+8); if (zc->rep[2] >= dictSize) return ERROR(dictionary_corrupted);
+    cctx->rep[0] = MEM_readLE32(dictPtr+0); if (cctx->rep[0] >= dictSize) return ERROR(dictionary_corrupted);
+    cctx->rep[1] = MEM_readLE32(dictPtr+4); if (cctx->rep[1] >= dictSize) return ERROR(dictionary_corrupted);
+    cctx->rep[2] = MEM_readLE32(dictPtr+8); if (cctx->rep[2] >= dictSize) return ERROR(dictionary_corrupted);
     dictPtr += 12;
 
-    zc->flagStaticTables = 1;
+    cctx->flagStaticTables = 1;
     return dictPtr - (const BYTE*)dict;
 }
 
diff --git a/lib/decompress/zstd_decompress.c b/lib/decompress/zstd_decompress.c
index 6d0903830..9bc888961 100644
--- a/lib/decompress/zstd_decompress.c
+++ b/lib/decompress/zstd_decompress.c
@@ -1186,7 +1186,7 @@ static void ZSTD_refDictContent(ZSTD_DCtx* dctx, const void* dict, size_t dictSi
     dctx->previousDstEnd = (const char*)dict + dictSize;
 }
 
-static size_t ZSTD_loadEntropy(ZSTD_DCtx* dctx, const void* dict, size_t const dictSize)
+static size_t ZSTD_loadEntropy(ZSTD_DCtx* dctx, const void* const dict, size_t const dictSize)
 {
     const BYTE* dictPtr = (const BYTE*)dict;
     const BYTE* const dictEnd = dict + dictSize;
@@ -1223,9 +1223,10 @@ static size_t ZSTD_loadEntropy(ZSTD_DCtx* dctx, const void* dict, size_t const d
         dictPtr += litlengthHeaderSize;
     }
 
-    dctx->rep[0] = MEM_readLE32(dictPtr+0);
-    dctx->rep[1] = MEM_readLE32(dictPtr+4);
-    dctx->rep[2] = MEM_readLE32(dictPtr+8);
+    if (dictPtr+12 > dictEnd) return ERROR(dictionary_corrupted);
+    dctx->rep[0] = MEM_readLE32(dictPtr+0); if (dctx->rep[0] >= dictSize) return ERROR(dictionary_corrupted);
+    dctx->rep[1] = MEM_readLE32(dictPtr+4); if (dctx->rep[1] >= dictSize) return ERROR(dictionary_corrupted);
+    dctx->rep[2] = MEM_readLE32(dictPtr+8); if (dctx->rep[2] >= dictSize) return ERROR(dictionary_corrupted);
     dictPtr += 12;
 
     dctx->litEntropy = dctx->fseEntropy = 1;