starred/brotli
1
0
Fork 0
mirror of https://github.com/google/brotli.git synced 2026-07-08 17:56:58 +00:00
Code Issues 1.2k Packages Projects Releases 20 Wiki Activity

Detect and report invalid stream earlier.

Browse Source 
PiperOrigin-RevId: 876198329
This commit is contained in:
Evgenii Kliuchnikov
2026-02-27 05:10:32 -08:00
committed by Copybara-Service
parent 34f020fa9d
commit 0ed4268a44
2 changed files with 59 additions and 32 deletions
Download Patch File Download Diff File Expand all files Collapse all files

87
c/dec/decode.c
View File

@@ -1176,7 +1176,7 @@ static BrotliDecoderErrorCode DecodeContextMap(brotli_reg_t context_map_size,
/* Decodes a command or literal and updates block type ring-buffer.
Reads 3..54 bits. */
static BROTLI_INLINE BROTLI_BOOL DecodeBlockTypeAndLength(
static BROTLI_INLINE BrotliDecoderErrorCode DecodeBlockTypeAndLength(
int safe, BrotliDecoderState* s, int tree_type) {
brotli_reg_t max_block_type = s->num_block_types[tree_type];
const HuffmanCode* type_tree = &s->block_type_trees[
@@ -1187,7 +1187,7 @@ static BROTLI_INLINE BROTLI_BOOL DecodeBlockTypeAndLength(
brotli_reg_t* ringbuffer = &s->block_type_rb[tree_type * 2];
brotli_reg_t block_type;
if (max_block_type <= 1) {
return BROTLI_FALSE;
return BROTLI_DECODER_ERROR_FORMAT_BLOCK_SWITCH;
}
/* Read 0..15 + 3..39 bits. */
@@ -1197,11 +1197,13 @@ static BROTLI_INLINE BROTLI_BOOL DecodeBlockTypeAndLength(
} else {
BrotliBitReaderState memento;
BrotliBitReaderSaveState(br, &memento);
if (!SafeReadSymbol(type_tree, br, &block_type)) return BROTLI_FALSE;
if (!SafeReadSymbol(type_tree, br, &block_type)) {
return BROTLI_DECODER_NEEDS_MORE_INPUT;
}
if (!SafeReadBlockLength(s, &s->block_length[tree_type], len_tree, br)) {
s->substate_read_block_length = BROTLI_STATE_READ_BLOCK_LENGTH_NONE;
BrotliBitReaderRestoreState(br, &memento);
return BROTLI_FALSE;
return BROTLI_DECODER_NEEDS_MORE_INPUT;
}
}
@@ -1217,7 +1219,7 @@ static BROTLI_INLINE BROTLI_BOOL DecodeBlockTypeAndLength(
}
ringbuffer[0] = ringbuffer[1];
ringbuffer[1] = block_type;
return BROTLI_TRUE;
return BROTLI_DECODER_SUCCESS;
}
static BROTLI_INLINE void DetectTrivialLiteralBlockTypes(
@@ -1254,59 +1256,65 @@ static BROTLI_INLINE void PrepareLiteralDecoding(BrotliDecoderState* s) {
/* Decodes the block type and updates the state for literal context.
Reads 3..54 bits. */
static BROTLI_INLINE BROTLI_BOOL DecodeLiteralBlockSwitchInternal(
static BROTLI_INLINE BrotliDecoderErrorCode DecodeLiteralBlockSwitchInternal(
int safe, BrotliDecoderState* s) {
if (!DecodeBlockTypeAndLength(safe, s, 0)) {
return BROTLI_FALSE;
BrotliDecoderErrorCode result = DecodeBlockTypeAndLength(safe, s, 0);
if (result != BROTLI_DECODER_SUCCESS) {
return result;
}
PrepareLiteralDecoding(s);
return BROTLI_TRUE;
return BROTLI_DECODER_SUCCESS;
}
static void BROTLI_NOINLINE DecodeLiteralBlockSwitch(BrotliDecoderState* s) {
DecodeLiteralBlockSwitchInternal(0, s);
static BROTLI_NOINLINE BrotliDecoderErrorCode
DecodeLiteralBlockSwitch(BrotliDecoderState* s) {
return DecodeLiteralBlockSwitchInternal(0, s);
}
static BROTLI_BOOL BROTLI_NOINLINE SafeDecodeLiteralBlockSwitch(
static BROTLI_NOINLINE BrotliDecoderErrorCode SafeDecodeLiteralBlockSwitch(
BrotliDecoderState* s) {
return DecodeLiteralBlockSwitchInternal(1, s);
}
/* Block switch for insert/copy length.
Reads 3..54 bits. */
static BROTLI_INLINE BROTLI_BOOL DecodeCommandBlockSwitchInternal(
static BROTLI_INLINE BrotliDecoderErrorCode DecodeCommandBlockSwitchInternal(
int safe, BrotliDecoderState* s) {
if (!DecodeBlockTypeAndLength(safe, s, 1)) {
return BROTLI_FALSE;
BrotliDecoderErrorCode result = DecodeBlockTypeAndLength(safe, s, 1);
if (result != BROTLI_DECODER_SUCCESS) {
return result;
}
s->htree_command = s->insert_copy_hgroup.htrees[s->block_type_rb[3]];
return BROTLI_TRUE;
return BROTLI_DECODER_SUCCESS;
}
static void BROTLI_NOINLINE DecodeCommandBlockSwitch(BrotliDecoderState* s) {
DecodeCommandBlockSwitchInternal(0, s);
static BROTLI_NOINLINE BrotliDecoderErrorCode
DecodeCommandBlockSwitch(BrotliDecoderState* s) {
return DecodeCommandBlockSwitchInternal(0, s);
}
static BROTLI_BOOL BROTLI_NOINLINE SafeDecodeCommandBlockSwitch(
BrotliDecoderState* s) {
static BROTLI_NOINLINE BrotliDecoderErrorCode
SafeDecodeCommandBlockSwitch(BrotliDecoderState* s) {
return DecodeCommandBlockSwitchInternal(1, s);
}
/* Block switch for distance codes.
Reads 3..54 bits. */
static BROTLI_INLINE BROTLI_BOOL DecodeDistanceBlockSwitchInternal(
static BROTLI_INLINE BrotliDecoderErrorCode DecodeDistanceBlockSwitchInternal(
int safe, BrotliDecoderState* s) {
if (!DecodeBlockTypeAndLength(safe, s, 2)) {
return BROTLI_FALSE;
BrotliDecoderErrorCode result = DecodeBlockTypeAndLength(safe, s, 2);
if (result != BROTLI_DECODER_SUCCESS) {
return result;
}
s->dist_context_map_slice = s->dist_context_map +
(s->block_type_rb[5] << BROTLI_DISTANCE_CONTEXT_BITS);
s->dist_htree_index = s->dist_context_map_slice[s->distance_context];
return BROTLI_TRUE;
return BROTLI_DECODER_SUCCESS;
}
static void BROTLI_NOINLINE DecodeDistanceBlockSwitch(BrotliDecoderState* s) {
DecodeDistanceBlockSwitchInternal(0, s);
static BROTLI_NOINLINE BrotliDecoderErrorCode
DecodeDistanceBlockSwitch(BrotliDecoderState* s) {
return DecodeDistanceBlockSwitchInternal(0, s);
}
static BROTLI_BOOL BROTLI_NOINLINE SafeDecodeDistanceBlockSwitch(
@@ -1940,6 +1948,9 @@ static BROTLI_INLINE BROTLI_BOOL CheckInputAmount(
return BrotliCheckInputAmount(br);
}
/* NB: METHOD should return BROTLI_FALSE only in case there is not enough input;
in case of "unsafe" execution, when input is guaranteed to be sufficient,
result is ignored. */
#define BROTLI_SAFE(METHOD) \
{ \
if (safe) { \
@@ -1952,6 +1963,22 @@ static BROTLI_INLINE BROTLI_BOOL CheckInputAmount(
} \
}
/* NB: METHOD should return BROTLI_DECODER_SUCCESS, BROTLI_DECODER_ERROR_*, or
BROTLI_DECODER_NEEDS_MORE_INPUT; the later two break the processing. */
#define BROTLI_SAFE_WITH_STATUS(METHOD) \
{ \
BrotliDecoderErrorCode status; \
if (safe) { \
status = Safe##METHOD; \
} else { \
status = METHOD; \
} \
if (status != BROTLI_DECODER_SUCCESS) { \
result = status; \
goto saveStateAndReturn; \
} \
}
static BROTLI_INLINE BrotliDecoderErrorCode ProcessCommandsInternal(
int safe, BrotliDecoderState* s) {
int pos = s->pos;
@@ -1991,7 +2018,7 @@ CommandBegin:
goto saveStateAndReturn;
}
if (BROTLI_PREDICT_FALSE(s->block_length[1] == 0)) {
BROTLI_SAFE(DecodeCommandBlockSwitch(s));
BROTLI_SAFE_WITH_STATUS(DecodeCommandBlockSwitch(s));
goto CommandBegin;
}
/* Read the insert/copy length in the command. */
@@ -2136,7 +2163,7 @@ CommandPostDecodeLiterals:
} else {
/* Read distance code in the command, unless it was implicitly zero. */
if (BROTLI_PREDICT_FALSE(s->block_length[2] == 0)) {
BROTLI_SAFE(DecodeDistanceBlockSwitch(s));
BROTLI_SAFE_WITH_STATUS(DecodeDistanceBlockSwitch(s));
}
BROTLI_SAFE(ReadDistance(s, br));
}
@@ -2330,7 +2357,7 @@ CommandPostWrapCopy:
}
NextLiteralBlock:
BROTLI_SAFE(DecodeLiteralBlockSwitch(s));
BROTLI_SAFE_WITH_STATUS(DecodeLiteralBlockSwitch(s));
goto CommandInner;
saveStateAndReturn:
@@ -2552,6 +2579,8 @@ BrotliDecoderResult BrotliDecoderDecompressStream(
if (result != BROTLI_DECODER_SUCCESS) {
break;
}
BROTLI_DCHECK(s->meta_block_remaining_len <=
(int)BROTLI_BLOCK_SIZE_CAP);
BROTLI_LOG_UINT(s->is_last_metablock);
BROTLI_LOG_UINT(s->meta_block_remaining_len);
BROTLI_LOG_UINT(s->is_metadata);

4
c/include/brotli/decode.h
View File

@@ -85,9 +85,7 @@ typedef enum {
BROTLI_ERROR_CODE(_ERROR_FORMAT_, PADDING_1, -14) SEPARATOR \
BROTLI_ERROR_CODE(_ERROR_FORMAT_, PADDING_2, -15) SEPARATOR \
BROTLI_ERROR_CODE(_ERROR_FORMAT_, DISTANCE, -16) SEPARATOR \
\
/* -17 code is reserved */ \
\
BROTLI_ERROR_CODE(_ERROR_FORMAT_, BLOCK_SWITCH, -17) SEPARATOR \
BROTLI_ERROR_CODE(_ERROR_, COMPOUND_DICTIONARY, -18) SEPARATOR \
BROTLI_ERROR_CODE(_ERROR_, DICTIONARY_NOT_SET, -19) SEPARATOR \
BROTLI_ERROR_CODE(_ERROR_, INVALID_ARGUMENTS, -20) SEPARATOR \