dany/libwebp
1
0
Fork 0
mirror of https://github.com/webmproject/libwebp.git synced 2025-07-19 07:20:02 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity

GetFeatures: Detect invalid VP8X/VP8/VP8L data

Browse Source 
This facilitates early error detection during decode/render.
Also, related refactoring.

Change-Id: Ia6c7cd91dec202a2a68dae2118f5981cf1eaa83d
This commit is contained in:
Urvang Joshi
2013-05-10 14:25:00 -07:00
parent 5818cff770
commit 352d0dee99
5 changed files with 31 additions and 54 deletions
Download Patch File Download Diff File Expand all files Collapse all files

47
src/mux/muxread.c
View File

@ -278,27 +278,34 @@ static WebPMuxError ValidateForSingleImage(const WebPMux* const mux) {
}
}
WebPMuxError MuxGetCanvasSize(const WebPMux* const mux, int* width,
int* height) {
// Get the canvas width, height and flags after validating that VP8X/VP8/VP8L
// chunk and canvas size are valid.
static WebPMuxError MuxGetCanvasInfo(const WebPMux* const mux,
int* width, int* height, uint32_t* flags) {
int w, h;
uint32_t f = 0;
WebPData data;
assert(mux != NULL);
// Check if VP8X chunk is present.
if (MuxGet(mux, IDX_VP8X, 1, &data) == WEBP_MUX_OK) {
if (data.size < VP8X_CHUNK_SIZE) return WEBP_MUX_BAD_DATA;
f = GetLE32(data.bytes);
w = GetLE24(data.bytes + 4) + 1;
h = GetLE24(data.bytes + 7) + 1;
} else { // Single image case.
int has_alpha;
WebPMuxError err = ValidateForSingleImage(mux);
if (err != WEBP_MUX_OK) return err;
err = MuxGetImageWidthHeight(mux->images_->img_, &w, &h);
err = MuxGetImageInfo(mux->images_->img_, &w, &h, &has_alpha);
if (err != WEBP_MUX_OK) return err;
if (has_alpha) f |= ALPHA_FLAG;
}
if (w * (uint64_t)h >= MAX_IMAGE_AREA) return WEBP_MUX_BAD_DATA;
if (width) *width = w;
if (height) *height = h;
if (width != NULL) *width = w;
if (height != NULL) *height = h;
if (flags != NULL) *flags = f;
return WEBP_MUX_OK;
}
@ -306,36 +313,12 @@ WebPMuxError WebPMuxGetCanvasSize(const WebPMux* mux, int* width, int* height) {
if (mux == NULL || width == NULL || height == NULL) {
return WEBP_MUX_INVALID_ARGUMENT;
}
return MuxGetCanvasSize(mux, width, height);
return MuxGetCanvasInfo(mux, width, height, NULL);
}
WebPMuxError WebPMuxGetFeatures(const WebPMux* mux, uint32_t* flags) {
WebPData data;
if (mux == NULL || flags == NULL) return WEBP_MUX_INVALID_ARGUMENT;
*flags = 0;
// Check if VP8X chunk is present.
if (MuxGet(mux, IDX_VP8X, 1, &data) == WEBP_MUX_OK) {
if (data.size < CHUNK_SIZE_BYTES) return WEBP_MUX_BAD_DATA;
*flags = GetLE32(data.bytes); // All OK. Fill up flags.
} else {
WebPMuxError err = ValidateForSingleImage(mux); // Check for single image.
if (err != WEBP_MUX_OK) return err;
if (MuxHasLosslessImages(mux->images_)) {
const WebPData* const vp8l_data = &mux->images_->img_->data_;
int has_alpha = 0;
if (!VP8LGetInfo(vp8l_data->bytes, vp8l_data->size, NULL, NULL,
&has_alpha)) {
return WEBP_MUX_BAD_DATA;
}
if (has_alpha) {
*flags = ALPHA_FLAG;
}
}
}
return WEBP_MUX_OK;
return MuxGetCanvasInfo(mux, NULL, NULL, flags);
}
static uint8_t* EmitVP8XChunk(uint8_t* const dst, int width,
@ -374,7 +357,7 @@ static WebPMuxError SynthesizeBitstream(const WebPMuxImage* const wpi,
int w, h;
WebPMuxError err;
assert(wpi->img_ != NULL);
err = MuxGetImageWidthHeight(wpi->img_, &w, &h);
err = MuxGetImageInfo(wpi->img_, &w, &h, NULL);
if (err != WEBP_MUX_OK) {
free(data);
return err;