From d294dd7fc684b1f46130358ff5c218e835082b16 Mon Sep 17 00:00:00 2001 From: Yann Collet Date: Fri, 27 Apr 2018 09:04:09 -0700 Subject: ensure favorDecSpeed is properly initialized also : - fix a potential malloc error - proper use of ALLOC macro inside lz4hc - update html API doc --- doc/lz4_manual.html | 12 +++++---- doc/lz4frame_manual.html | 63 +++++++++++++++++++++++++++++++++++++++++++++--- lib/lz4.c | 6 ++--- lib/lz4hc.c | 10 ++++---- 4 files changed, 74 insertions(+), 17 deletions(-) diff --git a/doc/lz4_manual.html b/doc/lz4_manual.html index f8639fe..ddd2724 100644 --- a/doc/lz4_manual.html +++ b/doc/lz4_manual.html @@ -126,15 +126,17 @@ int LZ4_compress_fast_extState (void* state, const char* src, char* dst, int src 
int LZ4_decompress_fast (const char* src, char* dst, int originalSize);
 
This function is a bit faster than LZ4_decompress_safe(),
-but doesn't provide any security guarantee.
+but it may misbehave on malformed input because it doesn't perform full validation of compressed data.
     originalSize : is the uncompressed size to regenerate
                    Destination buffer must be already allocated, and its size must be >= 'originalSize' bytes.
     return : number of bytes read from source buffer (== compressed size).
              If the source stream is detected malformed, the function stops decoding and return a negative result.
-    note : This function respects memory boundaries for *properly formed* compressed data.
-           However, it does not provide any protection against malicious input.
-           It also doesn't know 'src' size, and implies it's >= compressed size.
-           Use this function in trusted environment **only**.
+    note : This function is only usable if the originalSize of uncompressed data is known in advance.
+           The caller should also check that all the compressed input has been consumed properly,
+           i.e. that the return value matches the size of the buffer with compressed input.
+           The function never writes past the output buffer.  However, since it doesn't know its 'src' size,
+           it may read past the intended input.  Also, because match offsets are not validated during decoding,
+           reads from 'src' may underflow.  Use this function in trusted environment **only**.
 

int LZ4_decompress_safe_partial (const char* src, char* dst, int srcSize, int targetOutputSize, int dstCapacity);
diff --git a/doc/lz4frame_manual.html b/doc/lz4frame_manual.html
index 459bac8..53ea7eb 100644
--- a/doc/lz4frame_manual.html
+++ b/doc/lz4frame_manual.html
@@ -18,6 +18,7 @@
 
  • Compression
    • 
 
  • Decompression functions
    • 
 
  • Streaming decompression functions
    • 
+
  • Bulk processing dictionary API
    • 
 
 
    
 
    Introduction
    @@ -89,12 +90,13 @@
 
 
    typedef struct {
   LZ4F_frameInfo_t frameInfo;
-  int      compressionLevel;       /* 0: default (fast mode); values > LZ4HC_CLEVEL_MAX count as LZ4HC_CLEVEL_MAX; values < 0 trigger "fast acceleration" */
-  unsigned autoFlush;              /* 1 == always flush, to reduce usage of internal buffers */
-  unsigned reserved[4];            /* must be zero for forward compatibility */
+  int      compressionLevel;    /* 0: default (fast mode); values > LZ4HC_CLEVEL_MAX count as LZ4HC_CLEVEL_MAX; values < 0 trigger "fast acceleration" */
+  unsigned autoFlush;           /* 1: always flush, to reduce usage of internal buffers */
+  unsigned favorDecSpeed;       /* 1: parser favors decompression speed vs compression ratio. Only works for high compression modes (>= LZ4LZ4HC_CLEVEL_OPT_MIN) */  /* >= v1.8.2 */
+  unsigned reserved[3];         /* must be zero for forward compatibility */
 } LZ4F_preferences_t;
 
      makes it possible to supply detailed compression parameters to the stream interface.
-  It's not required to set all fields, as long as the structure was initially memset() to zero.
+  Structure is presumed initially memset() to zero, representing default settings.
   All reserved fields must be set to zero. 
 

    
 
@@ -293,5 +295,58 @@ LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* dctx);
   and start a new one using same context resources. 
 

    
 
+
    typedef enum { LZ4F_LIST_ERRORS(LZ4F_GENERATE_ENUM) } LZ4F_errorCodes;
+

    
+
    Bulk processing dictionary API
    
+
+
    LZ4FLIB_STATIC_API LZ4F_CDict* LZ4F_createCDict(const void* dictBuffer, size_t dictSize);
+LZ4FLIB_STATIC_API void        LZ4F_freeCDict(LZ4F_CDict* CDict);
+
      When compressing multiple messages / blocks with the same dictionary, it's recommended to load it just once.
+  LZ4_createCDict() will create a digested dictionary, ready to start future compression operations without startup delay.
+  LZ4_CDict can be created once and shared by multiple threads concurrently, since its usage is read-only.
+ `dictBuffer` can be released after LZ4_CDict creation, since its content is copied within CDict 
+

    
+
+
    LZ4FLIB_STATIC_API size_t LZ4F_compressFrame_usingCDict(
+    LZ4F_cctx* cctx,
+    void* dst, size_t dstCapacity,
+    const void* src, size_t srcSize,
+    const LZ4F_CDict* cdict,
+    const LZ4F_preferences_t* preferencesPtr);
+
      Compress an entire srcBuffer into a valid LZ4 frame using a digested Dictionary.
+  cctx must point to a context created by LZ4F_createCompressionContext().
+  If cdict==NULL, compress without a dictionary.
+  dstBuffer MUST be >= LZ4F_compressFrameBound(srcSize, preferencesPtr).
+  If this condition is not respected, function will fail (@return an errorCode).
+  The LZ4F_preferences_t structure is optional : you may provide NULL as argument,
+  but it's not recommended, as it's the only way to provide dictID in the frame header.
+ @return : number of bytes written into dstBuffer.
+           or an error code if it fails (can be tested using LZ4F_isError()) 
+

    
+
+
    LZ4FLIB_STATIC_API size_t LZ4F_compressBegin_usingCDict(
+    LZ4F_cctx* cctx,
+    void* dstBuffer, size_t dstCapacity,
+    const LZ4F_CDict* cdict,
+    const LZ4F_preferences_t* prefsPtr);
+
      Inits streaming dictionary compression, and writes the frame header into dstBuffer.
+  dstCapacity must be >= LZ4F_HEADER_SIZE_MAX bytes.
+ `prefsPtr` is optional : you may provide NULL as argument,
+  however, it's the only way to provide dictID in the frame header.
+ @return : number of bytes written into dstBuffer for the header,
+           or an error code (which can be tested using LZ4F_isError()) 
+

    
+
+
    LZ4FLIB_STATIC_API size_t LZ4F_decompress_usingDict(
+    LZ4F_dctx* dctxPtr,
+    void* dstBuffer, size_t* dstSizePtr,
+    const void* srcBuffer, size_t* srcSizePtr,
+    const void* dict, size_t dictSize,
+    const LZ4F_decompressOptions_t* decompressOptionsPtr);
+
      Same as LZ4F_decompress(), using a predefined dictionary.
+  Dictionary is used "in place", without any preprocessing.
+  It must remain accessible throughout the entire frame decoding. 
+

    
+
 
 
diff --git a/lib/lz4.c b/lib/lz4.c
index eaabe5b..deaec7b 100644
--- a/lib/lz4.c
+++ b/lib/lz4.c
@@ -161,11 +161,11 @@
 *  Memory routines
 **************************************/
 #include    /* malloc, calloc, free */
-#define ALLOC(s) malloc(s)
+#define ALLOC(s)          malloc(s)
 #define ALLOC_AND_ZERO(s) calloc(1,s)
-#define FREEMEM        free
+#define FREEMEM(p)        free(p)
 #include    /* memset, memcpy */
-#define MEM_INIT       memset
+#define MEM_INIT(p,v,s)   memset((p),(v),(s))
 
 
 /*-************************************
diff --git a/lib/lz4hc.c b/lib/lz4hc.c
index 35eac1a..1c7096b 100644
--- a/lib/lz4hc.c
+++ b/lib/lz4hc.c
@@ -805,7 +805,7 @@ int LZ4_compress_HC_extStateHC (void* state, const char* src, char* dst, int src
 int LZ4_compress_HC(const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel)
 {
 #if defined(LZ4HC_HEAPMODE) && LZ4HC_HEAPMODE==1
-    LZ4_streamHC_t* const statePtr = (LZ4_streamHC_t*)malloc(sizeof(LZ4_streamHC_t));
+    LZ4_streamHC_t* const statePtr = (LZ4_streamHC_t*)ALLOC(sizeof(LZ4_streamHC_t));
 #else
     LZ4_streamHC_t state;
     LZ4_streamHC_t* const statePtr = &state;
@@ -834,10 +834,9 @@ int LZ4_compress_HC_destSize(void* LZ4HC_Data, const char* source, char* dest, i
 **************************************/
 /* allocation */
 LZ4_streamHC_t* LZ4_createStreamHC(void) {
-    LZ4_streamHC_t* LZ4_streamHCPtr = (LZ4_streamHC_t*)malloc(sizeof(LZ4_streamHC_t));
-    LZ4_streamHCPtr->internal_donotuse.end = (const BYTE *)(ptrdiff_t)-1;
-    LZ4_streamHCPtr->internal_donotuse.base = NULL;
-    LZ4_streamHCPtr->internal_donotuse.dictCtx = NULL;
+    LZ4_streamHC_t* const LZ4_streamHCPtr = (LZ4_streamHC_t*)ALLOC(sizeof(LZ4_streamHC_t));
+    if (LZ4_streamHCPtr==NULL) return NULL;
+    LZ4_resetStreamHC(LZ4_streamHCPtr, LZ4HC_CLEVEL_DEFAULT);
     return LZ4_streamHCPtr;
 }
 
@@ -857,6 +856,7 @@ void LZ4_resetStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
     LZ4_streamHCPtr->internal_donotuse.end = (const BYTE *)(ptrdiff_t)-1;
     LZ4_streamHCPtr->internal_donotuse.base = NULL;
     LZ4_streamHCPtr->internal_donotuse.dictCtx = NULL;
+    LZ4_streamHCPtr->internal_donotuse.favorDecSpeed = 0;
     LZ4_setCompressionLevel(LZ4_streamHCPtr, compressionLevel);
 }
 
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