diff options
| -rw-r--r-- | indra/llimage/llimagedimensionsinfo.cpp | 83 | ||||
| -rw-r--r-- | indra/llimage/llimagedimensionsinfo.h | 3 |
2 files changed, 82 insertions, 4 deletions
diff --git a/indra/llimage/llimagedimensionsinfo.cpp b/indra/llimage/llimagedimensionsinfo.cpp index 835664c60f..c6bfa50b40 100644 --- a/indra/llimage/llimagedimensionsinfo.cpp +++ b/indra/llimage/llimagedimensionsinfo.cpp @@ -73,9 +73,28 @@ bool LLImageDimensionsInfo::load(const std::string& src_filename,U32 codec) bool LLImageDimensionsInfo::getImageDimensionsBmp() { - const S32 BMP_FILE_HEADER_SIZE = 14; + // Make sure the file is long enough. + const S32 DATA_LEN = 26; // BMP header (14) + DIB header size (4) + width (4) + height (4) + if (!checkFileLength(DATA_LEN)) + { + llwarns << "Premature end of file" << llendl; + return false; + } + + // Read BMP signature. + U8 signature[2]; + mInfile.read((void*)signature, sizeof(signature)/sizeof(signature[0])); + + // Make sure this is actually a BMP file. + // We only support Windows bitmaps (BM), according to LLImageBMP::updateData(). + if (signature[0] != 'B' || signature[1] != 'M') + { + llwarns << "Not a BMP" << llendl; + return false; + } - mInfile.seek(APR_CUR,BMP_FILE_HEADER_SIZE+4); + // Read image dimensions. + mInfile.seek(APR_CUR, 16); mWidth = read_reverse_s32(); mHeight = read_reverse_s32(); @@ -86,6 +105,14 @@ bool LLImageDimensionsInfo::getImageDimensionsTga() { const S32 TGA_FILE_HEADER_SIZE = 12; + // Make sure the file is long enough. + if (!checkFileLength(TGA_FILE_HEADER_SIZE + 1 /* width */ + 1 /* height */)) + { + llwarns << "Premature end of file" << llendl; + return false; + } + + // *TODO: Detect non-TGA files somehow. mInfile.seek(APR_CUR,TGA_FILE_HEADER_SIZE); mWidth = read_byte() | read_byte() << 8; mHeight = read_byte() | read_byte() << 8; @@ -95,9 +122,29 @@ bool LLImageDimensionsInfo::getImageDimensionsTga() bool LLImageDimensionsInfo::getImageDimensionsPng() { - const S32 PNG_FILE_MARKER_SIZE = 8; + const S32 PNG_MAGIC_SIZE = 8; + + // Make sure the file is long enough. + if (!checkFileLength(PNG_MAGIC_SIZE + 8 + sizeof(S32) * 2 /* width, height */)) + { + llwarns << "Premature end of file" << llendl; + return false; + } - mInfile.seek(APR_CUR,PNG_FILE_MARKER_SIZE + 8/*header offset+chunk length+chunk type*/); + // Read PNG signature. + const U8 png_magic[PNG_MAGIC_SIZE] = {0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A}; + U8 signature[PNG_MAGIC_SIZE]; + mInfile.read((void*)signature, PNG_MAGIC_SIZE); + + // Make sure it's a PNG file. + if (memcmp(signature, png_magic, PNG_MAGIC_SIZE) != 0) + { + llwarns << "Not a PNG" << llendl; + return false; + } + + // Read image dimensions. + mInfile.seek(APR_CUR, 8 /* chunk length + chunk type */); mWidth = read_s32(); mHeight = read_s32(); @@ -122,6 +169,24 @@ bool LLImageDimensionsInfo::getImageDimensionsJpeg() setLastError("Unable to open file for reading", mSrcFilename); return false; } + + /* Make sure this is a JPEG file. */ + const size_t JPEG_MAGIC_SIZE = 2; + const uint8_t jpeg_magic[JPEG_MAGIC_SIZE] = {0xFF, 0xD8}; + uint8_t signature[JPEG_MAGIC_SIZE]; + + if (fread(signature, sizeof(signature), 1, fp) != 1) + { + llwarns << "Premature end of file" << llendl; + return false; + } + if (memcmp(signature, jpeg_magic, JPEG_MAGIC_SIZE) != 0) + { + llwarns << "Not a JPEG" << llendl; + return false; + } + fseek(fp, 0, SEEK_SET); // go back to start of the file + /* Init jpeg */ jpeg_error_mgr jerr; jpeg_decompress_struct cinfo; @@ -145,3 +210,13 @@ bool LLImageDimensionsInfo::getImageDimensionsJpeg() return !sJpegErrorEncountered; } +bool LLImageDimensionsInfo::checkFileLength(S32 min_len) +{ + // Make sure the file is not shorter than min_len bytes. + // so that we don't have to check value returned by each read() or seek(). + char* buf = new char[min_len]; + int nread = mInfile.read(buf, min_len); + delete[] buf; + mInfile.seek(APR_SET, 0); + return nread == min_len; +} diff --git a/indra/llimage/llimagedimensionsinfo.h b/indra/llimage/llimagedimensionsinfo.h index 5384faf3f4..382fdb2a0e 100644 --- a/indra/llimage/llimagedimensionsinfo.h +++ b/indra/llimage/llimagedimensionsinfo.h @@ -119,6 +119,9 @@ protected: return read_byte() << 8 | read_byte(); } + /// Check if the file is not shorter than min_len bytes. + bool checkFileLength(S32 min_len); + protected: LLAPRFile mInfile ; std::string mSrcFilename; |