+
+/* Added at libpng version 1.2.34 and 1.4.0 (moved from pngset.c) */
+#ifdef PNG_cHRM_SUPPORTED
+#ifdef PNG_CHECK_cHRM_SUPPORTED
+
+/*
+ * Multiply two 32-bit numbers, V1 and V2, using 32-bit
+ * arithmetic, to produce a 64 bit result in the HI/LO words.
+ *
+ * A B
+ * x C D
+ * ------
+ * AD || BD
+ * AC || CB || 0
+ *
+ * where A and B are the high and low 16-bit words of V1,
+ * C and D are the 16-bit words of V2, AD is the product of
+ * A and D, and X || Y is (X << 16) + Y.
+*/
+
+void /* PRIVATE */
+png_64bit_product (long v1, long v2, unsigned long *hi_product,
+ unsigned long *lo_product)
+{
+ int a, b, c, d;
+ long lo, hi, x, y;
+
+ a = (v1 >> 16) & 0xffff;
+ b = v1 & 0xffff;
+ c = (v2 >> 16) & 0xffff;
+ d = v2 & 0xffff;
+
+ lo = b * d; /* BD */
+ x = a * d + c * b; /* AD + CB */
+ y = ((lo >> 16) & 0xffff) + x;
+
+ lo = (lo & 0xffff) | ((y & 0xffff) << 16);
+ hi = (y >> 16) & 0xffff;
+
+ hi += a * c; /* AC */
+
+ *hi_product = (unsigned long)hi;
+ *lo_product = (unsigned long)lo;
+}
+
+int /* PRIVATE */
+png_check_cHRM_fixed(png_structp png_ptr,
+ png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x,
+ png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y,
+ png_fixed_point blue_x, png_fixed_point blue_y)
+{
+ int ret = 1;
+ unsigned long xy_hi,xy_lo,yx_hi,yx_lo;
+
+ png_debug(1, "in function png_check_cHRM_fixed");
+
+ if (png_ptr == NULL)
+ return 0;
+
+ if (white_x < 0 || white_y <= 0 ||
+ red_x < 0 || red_y < 0 ||
+ green_x < 0 || green_y < 0 ||
+ blue_x < 0 || blue_y < 0)
+ {
+ png_warning(png_ptr,
+ "Ignoring attempt to set negative chromaticity value");
+ ret = 0;
+ }
+ if (white_x > (png_fixed_point) PNG_UINT_31_MAX ||
+ white_y > (png_fixed_point) PNG_UINT_31_MAX ||
+ red_x > (png_fixed_point) PNG_UINT_31_MAX ||
+ red_y > (png_fixed_point) PNG_UINT_31_MAX ||
+ green_x > (png_fixed_point) PNG_UINT_31_MAX ||
+ green_y > (png_fixed_point) PNG_UINT_31_MAX ||
+ blue_x > (png_fixed_point) PNG_UINT_31_MAX ||
+ blue_y > (png_fixed_point) PNG_UINT_31_MAX )
+ {
+ png_warning(png_ptr,
+ "Ignoring attempt to set chromaticity value exceeding 21474.83");
+ ret = 0;
+ }
+ if (white_x > 100000L - white_y)
+ {
+ png_warning(png_ptr, "Invalid cHRM white point");
+ ret = 0;
+ }
+ if (red_x > 100000L - red_y)
+ {
+ png_warning(png_ptr, "Invalid cHRM red point");
+ ret = 0;
+ }
+ if (green_x > 100000L - green_y)
+ {
+ png_warning(png_ptr, "Invalid cHRM green point");
+ ret = 0;
+ }
+ if (blue_x > 100000L - blue_y)
+ {
+ png_warning(png_ptr, "Invalid cHRM blue point");
+ ret = 0;
+ }
+
+ png_64bit_product(green_x - red_x, blue_y - red_y, &xy_hi, &xy_lo);
+ png_64bit_product(green_y - red_y, blue_x - red_x, &yx_hi, &yx_lo);
+
+ if (xy_hi == yx_hi && xy_lo == yx_lo)
+ {
+ png_warning(png_ptr,
+ "Ignoring attempt to set cHRM RGB triangle with zero area");
+ ret = 0;
+ }
+
+ return ret;
+}
+#endif /* PNG_CHECK_cHRM_SUPPORTED */
+#endif /* PNG_cHRM_SUPPORTED */
+
+void /* PRIVATE */
+png_check_IHDR(png_structp png_ptr,
+ png_uint_32 width, png_uint_32 height, int bit_depth,
+ int color_type, int interlace_type, int compression_type,
+ int filter_type)
+{
+ int error = 0;
+
+ /* Check for width and height valid values */
+ if (width == 0)
+ {
+ png_warning(png_ptr, "Image width is zero in IHDR");
+ error = 1;
+ }
+
+ if (height == 0)
+ {
+ png_warning(png_ptr, "Image height is zero in IHDR");
+ error = 1;
+ }
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+ if (width > png_ptr->user_width_max || width > PNG_USER_WIDTH_MAX)
+#else
+ if (width > PNG_USER_WIDTH_MAX)
+#endif
+ {
+ png_warning(png_ptr, "Image width exceeds user limit in IHDR");
+ error = 1;
+ }
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+ if (height > png_ptr->user_height_max || height > PNG_USER_HEIGHT_MAX)
+#else
+ if (height > PNG_USER_HEIGHT_MAX)
+#endif
+ {
+ png_warning(png_ptr, "Image height exceeds user limit in IHDR");
+ error = 1;
+ }
+
+ if (width > PNG_UINT_31_MAX)
+ {
+ png_warning(png_ptr, "Invalid image width in IHDR");
+ error = 1;
+ }
+
+ if ( height > PNG_UINT_31_MAX)
+ {
+ png_warning(png_ptr, "Invalid image height in IHDR");
+ error = 1;
+ }
+
+ if ( width > (PNG_UINT_32_MAX
+ >> 3) /* 8-byte RGBA pixels */
+ - 64 /* bigrowbuf hack */
+ - 1 /* filter byte */
+ - 7*8 /* rounding of width to multiple of 8 pixels */
+ - 8) /* extra max_pixel_depth pad */
+ png_warning(png_ptr, "Width is too large for libpng to process pixels");
+
+ /* Check other values */
+ if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 &&
+ bit_depth != 8 && bit_depth != 16)
+ {
+ png_warning(png_ptr, "Invalid bit depth in IHDR");
+ error = 1;
+ }
+
+ if (color_type < 0 || color_type == 1 ||
+ color_type == 5 || color_type > 6)
+ {
+ png_warning(png_ptr, "Invalid color type in IHDR");
+ error = 1;
+ }
+
+ if (((color_type == PNG_COLOR_TYPE_PALETTE) && bit_depth > 8) ||
+ ((color_type == PNG_COLOR_TYPE_RGB ||
+ color_type == PNG_COLOR_TYPE_GRAY_ALPHA ||
+ color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8))
+ {
+ png_warning(png_ptr, "Invalid color type/bit depth combination in IHDR");
+ error = 1;
+ }
+
+ if (interlace_type >= PNG_INTERLACE_LAST)
+ {
+ png_warning(png_ptr, "Unknown interlace method in IHDR");
+ error = 1;
+ }
+
+ if (compression_type != PNG_COMPRESSION_TYPE_BASE)
+ {
+ png_warning(png_ptr, "Unknown compression method in IHDR");
+ error = 1;
+ }
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ /* Accept filter_method 64 (intrapixel differencing) only if
+ * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
+ * 2. Libpng did not read a PNG signature (this filter_method is only
+ * used in PNG datastreams that are embedded in MNG datastreams) and
+ * 3. The application called png_permit_mng_features with a mask that
+ * included PNG_FLAG_MNG_FILTER_64 and
+ * 4. The filter_method is 64 and
+ * 5. The color_type is RGB or RGBA
+ */
+ if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) &&
+ png_ptr->mng_features_permitted)
+ png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
+
+ if (filter_type != PNG_FILTER_TYPE_BASE)
+ {
+ if (!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+ (filter_type == PNG_INTRAPIXEL_DIFFERENCING) &&
+ ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) == 0) &&
+ (color_type == PNG_COLOR_TYPE_RGB ||
+ color_type == PNG_COLOR_TYPE_RGB_ALPHA)))
+ {
+ png_warning(png_ptr, "Unknown filter method in IHDR");
+ error = 1;
+ }
+
+ if (png_ptr->mode & PNG_HAVE_PNG_SIGNATURE)
+ {
+ png_warning(png_ptr, "Invalid filter method in IHDR");
+ error = 1;
+ }
+ }
+
+#else
+ if (filter_type != PNG_FILTER_TYPE_BASE)
+ {
+ png_warning(png_ptr, "Unknown filter method in IHDR");
+ error = 1;
+ }
+#endif
+
+ if (error == 1)
+ png_error(png_ptr, "Invalid IHDR data");
+}
+#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
projects / wxWidgets.git / blobdiff