/* pngrutil.c - utilities to read a PNG file
*
- * Last changed in libpng 1.5.6 [November 3, 2011]
- * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.2 [April 25, 2013]
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
*
#define png_strtod(p,a,b) strtod(a,b)
png_uint_32 PNGAPI
-png_get_uint_31(png_structp png_ptr, png_const_bytep buf)
+png_get_uint_31(png_const_structrp png_ptr, png_const_bytep buf)
{
png_uint_32 uval = png_get_uint_32(buf);
#define PNG_FIXED_ERROR (-1)
static png_fixed_point /* PRIVATE */
-png_get_fixed_point(png_structp png_ptr, png_const_bytep buf)
+png_get_fixed_point(png_structrp png_ptr, png_const_bytep buf)
{
png_uint_32 uval = png_get_uint_32(buf);
/* Read and check the PNG file signature */
void /* PRIVATE */
-png_read_sig(png_structp png_ptr, png_infop info_ptr)
+png_read_sig(png_structrp png_ptr, png_inforp info_ptr)
{
png_size_t num_checked, num_to_check;
* Put the type name into png_ptr->chunk_name, and return the length.
*/
png_uint_32 /* PRIVATE */
-png_read_chunk_header(png_structp png_ptr)
+png_read_chunk_header(png_structrp png_ptr)
{
png_byte buf[8];
png_uint_32 length;
/* Read data, and (optionally) run it through the CRC. */
void /* PRIVATE */
-png_crc_read(png_structp png_ptr, png_bytep buf, png_size_t length)
+png_crc_read(png_structrp png_ptr, png_bytep buf, png_uint_32 length)
{
if (png_ptr == NULL)
return;
}
/* Optionally skip data and then check the CRC. Depending on whether we
- * are reading a ancillary or critical chunk, and how the program has set
+ * are reading an ancillary or critical chunk, and how the program has set
* things up, we may calculate the CRC on the data and print a message.
* Returns '1' if there was a CRC error, '0' otherwise.
*/
int /* PRIVATE */
-png_crc_finish(png_structp png_ptr, png_uint_32 skip)
+png_crc_finish(png_structrp png_ptr, png_uint_32 skip)
{
- png_size_t i;
- png_size_t istop = png_ptr->zbuf_size;
-
- for (i = (png_size_t)skip; i > istop; i -= istop)
+ /* The size of the local buffer for inflate is a good guess as to a
+ * reasonable size to use for buffering reads from the application.
+ */
+ while (skip > 0)
{
- png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
- }
+ png_uint_32 len;
+ png_byte tmpbuf[PNG_INFLATE_BUF_SIZE];
- if (i)
- {
- png_crc_read(png_ptr, png_ptr->zbuf, i);
+ len = (sizeof tmpbuf);
+ if (len > skip)
+ len = skip;
+ skip -= len;
+
+ png_crc_read(png_ptr, tmpbuf, len);
}
if (png_crc_error(png_ptr))
{
- if (PNG_CHUNK_ANCILLIARY(png_ptr->chunk_name) ?
+ if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) ?
!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) :
(png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE))
{
* the data it has read thus far.
*/
int /* PRIVATE */
-png_crc_error(png_structp png_ptr)
+png_crc_error(png_structrp png_ptr)
{
png_byte crc_bytes[4];
png_uint_32 crc;
int need_crc = 1;
- if (PNG_CHUNK_ANCILLIARY(png_ptr->chunk_name))
+ if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name))
{
if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
(PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
return (0);
}
-#ifdef PNG_READ_COMPRESSED_TEXT_SUPPORTED
-static png_size_t
-png_inflate(png_structp png_ptr, png_bytep data, png_size_t size,
- png_bytep output, png_size_t output_size)
+/* Manage the read buffer; this simply reallocates the buffer if it is not small
+ * enough (or if it is not allocated). The routine returns a pointer to the
+ * buffer; if an error occurs and 'warn' is set the routine returns NULL, else
+ * it will call png_error (via png_malloc) on failure. (warn == 2 means
+ * 'silent').
+ */
+static png_bytep
+png_read_buffer(png_structrp png_ptr, png_alloc_size_t new_size, int warn)
{
- png_size_t count = 0;
-
- /* zlib can't necessarily handle more than 65535 bytes at once (i.e. it can't
- * even necessarily handle 65536 bytes) because the type uInt is "16 bits or
- * more". Consequently it is necessary to chunk the input to zlib. This
- * code uses ZLIB_IO_MAX, from pngpriv.h, as the maximum (the maximum value
- * that can be stored in a uInt.) It is possible to set ZLIB_IO_MAX to a
- * lower value in pngpriv.h and this may sometimes have a performance
- * advantage, because it forces access of the input data to be separated from
- * at least some of the use by some period of time.
- */
- png_ptr->zstream.next_in = data;
- /* avail_in is set below from 'size' */
- png_ptr->zstream.avail_in = 0;
+ png_bytep buffer = png_ptr->read_buffer;
- while (1)
+ if (buffer != NULL && new_size > png_ptr->read_buffer_size)
{
- int ret, avail;
+ png_ptr->read_buffer = NULL;
+ png_ptr->read_buffer = NULL;
+ png_ptr->read_buffer_size = 0;
+ png_free(png_ptr, buffer);
+ buffer = NULL;
+ }
- /* The setting of 'avail_in' used to be outside the loop; by setting it
- * inside it is possible to chunk the input to zlib and simply rely on
- * zlib to advance the 'next_in' pointer. This allows arbitrary amounts o
- * data to be passed through zlib at the unavoidable cost of requiring a
- * window save (memcpy of up to 32768 output bytes) every ZLIB_IO_MAX
- * input bytes.
- */
- if (png_ptr->zstream.avail_in == 0 && size > 0)
+ if (buffer == NULL)
+ {
+ buffer = png_voidcast(png_bytep, png_malloc_base(png_ptr, new_size));
+
+ if (buffer != NULL)
{
- if (size <= ZLIB_IO_MAX)
- {
- /* The value is less than ZLIB_IO_MAX so the cast is safe: */
- png_ptr->zstream.avail_in = (uInt)size;
- size = 0;
- }
+ png_ptr->read_buffer = buffer;
+ png_ptr->read_buffer_size = new_size;
+ }
+ else if (warn < 2) /* else silent */
+ {
+#ifdef PNG_WARNINGS_SUPPORTED
+ if (warn)
+ png_chunk_warning(png_ptr, "insufficient memory to read chunk");
else
+#endif
{
- png_ptr->zstream.avail_in = ZLIB_IO_MAX;
- size -= ZLIB_IO_MAX;
+#ifdef PNG_ERROR_TEXT_SUPPORTED
+ png_chunk_error(png_ptr, "insufficient memory to read chunk");
+#endif
}
}
+ }
- /* Reset the output buffer each time round - we empty it
- * after every inflate call.
+ return buffer;
+}
+
+/* png_inflate_claim: claim the zstream for some nefarious purpose that involves
+ * decompression. Returns Z_OK on success, else a zlib error code. It checks
+ * the owner but, in final release builds, just issues a warning if some other
+ * chunk apparently owns the stream. Prior to release it does a png_error.
+ */
+static int
+png_inflate_claim(png_structrp png_ptr, png_uint_32 owner, int window_bits)
+{
+ if (png_ptr->zowner != 0)
+ {
+ char msg[64];
+
+ PNG_STRING_FROM_CHUNK(msg, png_ptr->zowner);
+ /* So the message that results is "<chunk> using zstream"; this is an
+ * internal error, but is very useful for debugging. i18n requirements
+ * are minimal.
*/
- png_ptr->zstream.next_out = png_ptr->zbuf;
- png_ptr->zstream.avail_out = png_ptr->zbuf_size;
+ (void)png_safecat(msg, (sizeof msg), 4, " using zstream");
+# if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC
+ png_chunk_warning(png_ptr, msg);
+ png_ptr->zowner = 0;
+# else
+ png_chunk_error(png_ptr, msg);
+# endif
+ }
- ret = inflate(&png_ptr->zstream, Z_NO_FLUSH);
- avail = png_ptr->zbuf_size - png_ptr->zstream.avail_out;
+ /* Implementation note: unlike 'png_deflate_claim' this internal function
+ * does not take the size of the data as an argument. Some efficiency could
+ * be gained by using this when it is known *if* the zlib stream itself does
+ * not record the number; however, this is an illusion: the original writer
+ * of the PNG may have selected a lower window size, and we really must
+ * follow that because, for systems with with limited capabilities, we
+ * would otherwise reject the application's attempts to use a smaller window
+ * size (zlib doesn't have an interface to say "this or lower"!).
+ *
+ * inflateReset2 was added to zlib 1.2.4; before this the window could not be
+ * reset, therefore it is necessary to always allocate the maximum window
+ * size with earlier zlibs just in case later compressed chunks need it.
+ */
+ {
+ int ret; /* zlib return code */
- /* First copy/count any new output - but only if we didn't
- * get an error code.
+ /* Set this for safety, just in case the previous owner left pointers to
+ * memory allocations.
*/
- if ((ret == Z_OK || ret == Z_STREAM_END) && avail > 0)
- {
- png_size_t space = avail; /* > 0, see above */
+ png_ptr->zstream.next_in = NULL;
+ png_ptr->zstream.avail_in = 0;
+ png_ptr->zstream.next_out = NULL;
+ png_ptr->zstream.avail_out = 0;
- if (output != 0 && output_size > count)
- {
- png_size_t copy = output_size - count;
+ if (png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED)
+ {
+# if ZLIB_VERNUM < 0x1240
+ PNG_UNUSED(window_bits)
+ ret = inflateReset(&png_ptr->zstream);
+# else
+ ret = inflateReset2(&png_ptr->zstream, window_bits);
+# endif
+ }
- if (space < copy)
- copy = space;
+ else
+ {
+# if ZLIB_VERNUM < 0x1240
+ ret = inflateInit(&png_ptr->zstream);
+# else
+ ret = inflateInit2(&png_ptr->zstream, window_bits);
+# endif
- png_memcpy(output + count, png_ptr->zbuf, copy);
- }
- count += space;
+ if (ret == Z_OK)
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED;
}
if (ret == Z_OK)
- continue;
+ png_ptr->zowner = owner;
- /* Termination conditions - always reset the zstream, it
- * must be left in inflateInit state.
+ else
+ png_zstream_error(png_ptr, ret);
+
+ return ret;
+ }
+}
+
+#ifdef PNG_READ_COMPRESSED_TEXT_SUPPORTED
+/* png_inflate now returns zlib error codes including Z_OK and Z_STREAM_END to
+ * allow the caller to do multiple calls if required. If the 'finish' flag is
+ * set Z_FINISH will be passed to the final inflate() call and Z_STREAM_END must
+ * be returned or there has been a problem, otherwise Z_SYNC_FLUSH is used and
+ * Z_OK or Z_STREAM_END will be returned on success.
+ *
+ * The input and output sizes are updated to the actual amounts of data consumed
+ * or written, not the amount available (as in a z_stream). The data pointers
+ * are not changed, so the next input is (data+input_size) and the next
+ * available output is (output+output_size).
+ */
+static int
+png_inflate(png_structrp png_ptr, png_uint_32 owner, int finish,
+ /* INPUT: */ png_const_bytep input, png_uint_32p input_size_ptr,
+ /* OUTPUT: */ png_bytep output, png_alloc_size_t *output_size_ptr)
+{
+ if (png_ptr->zowner == owner) /* Else not claimed */
+ {
+ int ret;
+ png_alloc_size_t avail_out = *output_size_ptr;
+ png_uint_32 avail_in = *input_size_ptr;
+
+ /* zlib can't necessarily handle more than 65535 bytes at once (i.e. it
+ * can't even necessarily handle 65536 bytes) because the type uInt is
+ * "16 bits or more". Consequently it is necessary to chunk the input to
+ * zlib. This code uses ZLIB_IO_MAX, from pngpriv.h, as the maximum (the
+ * maximum value that can be stored in a uInt.) It is possible to set
+ * ZLIB_IO_MAX to a lower value in pngpriv.h and this may sometimes have
+ * a performance advantage, because it reduces the amount of data accessed
+ * at each step and that may give the OS more time to page it in.
*/
+ png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input);
+ /* avail_in and avail_out are set below from 'size' */
png_ptr->zstream.avail_in = 0;
- inflateReset(&png_ptr->zstream);
-
- if (ret == Z_STREAM_END)
- return count; /* NOTE: may be zero. */
+ png_ptr->zstream.avail_out = 0;
- /* Now handle the error codes - the API always returns 0
- * and the error message is dumped into the uncompressed
- * buffer if available.
+ /* Read directly into the output if it is available (this is set to
+ * a local buffer below if output is NULL).
*/
-# ifdef PNG_WARNINGS_SUPPORTED
+ if (output != NULL)
+ png_ptr->zstream.next_out = output;
+
+ do
{
- png_const_charp msg;
+ uInt avail;
+ Byte local_buffer[PNG_INFLATE_BUF_SIZE];
+
+ /* zlib INPUT BUFFER */
+ /* The setting of 'avail_in' used to be outside the loop; by setting it
+ * inside it is possible to chunk the input to zlib and simply rely on
+ * zlib to advance the 'next_in' pointer. This allows arbitrary
+ * amounts of data to be passed through zlib at the unavoidable cost of
+ * requiring a window save (memcpy of up to 32768 output bytes)
+ * every ZLIB_IO_MAX input bytes.
+ */
+ avail_in += png_ptr->zstream.avail_in; /* not consumed last time */
- if (png_ptr->zstream.msg != 0)
- msg = png_ptr->zstream.msg;
+ avail = ZLIB_IO_MAX;
- else switch (ret)
- {
- case Z_BUF_ERROR:
- msg = "Buffer error in compressed datastream";
- break;
+ if (avail_in < avail)
+ avail = (uInt)avail_in; /* safe: < than ZLIB_IO_MAX */
- case Z_DATA_ERROR:
- msg = "Data error in compressed datastream";
- break;
+ avail_in -= avail;
+ png_ptr->zstream.avail_in = avail;
- default:
- msg = "Incomplete compressed datastream";
- break;
+ /* zlib OUTPUT BUFFER */
+ avail_out += png_ptr->zstream.avail_out; /* not written last time */
+
+ avail = ZLIB_IO_MAX; /* maximum zlib can process */
+
+ if (output == NULL)
+ {
+ /* Reset the output buffer each time round if output is NULL and
+ * make available the full buffer, up to 'remaining_space'
+ */
+ png_ptr->zstream.next_out = local_buffer;
+ if ((sizeof local_buffer) < avail)
+ avail = (sizeof local_buffer);
}
- png_chunk_warning(png_ptr, msg);
- }
-# endif
+ if (avail_out < avail)
+ avail = (uInt)avail_out; /* safe: < ZLIB_IO_MAX */
- /* 0 means an error - notice that this code simply ignores
- * zero length compressed chunks as a result.
+ png_ptr->zstream.avail_out = avail;
+ avail_out -= avail;
+
+ /* zlib inflate call */
+ /* In fact 'avail_out' may be 0 at this point, that happens at the end
+ * of the read when the final LZ end code was not passed at the end of
+ * the previous chunk of input data. Tell zlib if we have reached the
+ * end of the output buffer.
+ */
+ ret = inflate(&png_ptr->zstream, avail_out > 0 ? Z_NO_FLUSH :
+ (finish ? Z_FINISH : Z_SYNC_FLUSH));
+ } while (ret == Z_OK);
+
+ /* For safety kill the local buffer pointer now */
+ if (output == NULL)
+ png_ptr->zstream.next_out = NULL;
+
+ /* Claw back the 'size' and 'remaining_space' byte counts. */
+ avail_in += png_ptr->zstream.avail_in;
+ avail_out += png_ptr->zstream.avail_out;
+
+ /* Update the input and output sizes; the updated values are the amount
+ * consumed or written, effectively the inverse of what zlib uses.
*/
- return 0;
+ if (avail_out > 0)
+ *output_size_ptr -= avail_out;
+
+ if (avail_in > 0)
+ *input_size_ptr -= avail_in;
+
+ /* Ensure png_ptr->zstream.msg is set (even in the success case!) */
+ png_zstream_error(png_ptr, ret);
+ return ret;
+ }
+
+ else
+ {
+ /* This is a bad internal error. The recovery assigns to the zstream msg
+ * pointer, which is not owned by the caller, but this is safe; it's only
+ * used on errors!
+ */
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed");
+ return Z_STREAM_ERROR;
}
}
/*
- * Decompress trailing data in a chunk. The assumption is that chunkdata
+ * Decompress trailing data in a chunk. The assumption is that read_buffer
* points at an allocated area holding the contents of a chunk with a
* trailing compressed part. What we get back is an allocated area
* holding the original prefix part and an uncompressed version of the
* trailing part (the malloc area passed in is freed).
*/
-void /* PRIVATE */
-png_decompress_chunk(png_structp png_ptr, int comp_type,
- png_size_t chunklength,
- png_size_t prefix_size, png_size_t *newlength)
+static int
+png_decompress_chunk(png_structrp png_ptr,
+ png_uint_32 chunklength, png_uint_32 prefix_size,
+ png_alloc_size_t *newlength /* must be initialized to the maximum! */,
+ int terminate /*add a '\0' to the end of the uncompressed data*/)
{
- /* The caller should guarantee this */
- if (prefix_size > chunklength)
- {
- /* The recovery is to delete the chunk. */
- png_warning(png_ptr, "invalid chunklength");
- prefix_size = 0; /* To delete everything */
- }
+ /* TODO: implement different limits for different types of chunk.
+ *
+ * The caller supplies *newlength set to the maximum length of the
+ * uncompressed data, but this routine allocates space for the prefix and
+ * maybe a '\0' terminator too. We have to assume that 'prefix_size' is
+ * limited only by the maximum chunk size.
+ */
+ png_alloc_size_t limit = PNG_SIZE_MAX;
+
+# ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
+ if (png_ptr->user_chunk_malloc_max > 0 &&
+ png_ptr->user_chunk_malloc_max < limit)
+ limit = png_ptr->user_chunk_malloc_max;
+# elif PNG_USER_CHUNK_MALLOC_MAX > 0
+ if (PNG_USER_CHUNK_MALLOC_MAX < limit)
+ limit = PNG_USER_CHUNK_MALLOC_MAX;
+# endif
- else if (comp_type == PNG_COMPRESSION_TYPE_BASE)
+ if (limit >= prefix_size + (terminate != 0))
{
- png_size_t expanded_size = png_inflate(png_ptr,
- (png_bytep)(png_ptr->chunkdata + prefix_size),
- chunklength - prefix_size,
- 0, /* output */
- 0); /* output size */
+ int ret;
- /* Now check the limits on this chunk - if the limit fails the
- * compressed data will be removed, the prefix will remain.
- */
-#ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
- if (png_ptr->user_chunk_malloc_max &&
- (prefix_size + expanded_size >= png_ptr->user_chunk_malloc_max - 1))
-#else
-# ifdef PNG_USER_CHUNK_MALLOC_MAX
- if ((PNG_USER_CHUNK_MALLOC_MAX > 0) &&
- prefix_size + expanded_size >= PNG_USER_CHUNK_MALLOC_MAX - 1)
-# endif
-#endif
- png_warning(png_ptr, "Exceeded size limit while expanding chunk");
+ limit -= prefix_size + (terminate != 0);
+
+ if (limit < *newlength)
+ *newlength = limit;
- /* If the size is zero either there was an error and a message
- * has already been output (warning) or the size really is zero
- * and we have nothing to do - the code will exit through the
- * error case below.
+ /* Now try to claim the stream; the 'warn' setting causes zlib to be told
+ * to use the maximum window size during inflate; this hides errors in the
+ * deflate header window bits value which is used if '0' is passed. In
+ * fact this only has an effect with zlib versions 1.2.4 and later - see
+ * the comments in png_inflate_claim above.
*/
-#if defined(PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED) || \
- defined(PNG_USER_CHUNK_MALLOC_MAX)
- else if (expanded_size > 0)
-#else
- if (expanded_size > 0)
-#endif
+ ret = png_inflate_claim(png_ptr, png_ptr->chunk_name,
+ png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN ? 15 : 0);
+
+ if (ret == Z_OK)
{
- /* Success (maybe) - really uncompress the chunk. */
- png_size_t new_size = 0;
- png_charp text = (png_charp)png_malloc_warn(png_ptr,
- prefix_size + expanded_size + 1);
+ png_uint_32 lzsize = chunklength - prefix_size;
+
+ ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/,
+ /* input: */ png_ptr->read_buffer + prefix_size, &lzsize,
+ /* output: */ NULL, newlength);
- if (text != NULL)
+ if (ret == Z_STREAM_END)
{
- png_memcpy(text, png_ptr->chunkdata, prefix_size);
- new_size = png_inflate(png_ptr,
- (png_bytep)(png_ptr->chunkdata + prefix_size),
- chunklength - prefix_size,
- (png_bytep)(text + prefix_size), expanded_size);
- text[prefix_size + expanded_size] = 0; /* just in case */
-
- if (new_size == expanded_size)
+ /* Use 'inflateReset' here, not 'inflateReset2' because this
+ * preserves the previously decided window size (otherwise it would
+ * be necessary to store the previous window size.) In practice
+ * this doesn't matter anyway, because png_inflate will call inflate
+ * with Z_FINISH in almost all cases, so the window will not be
+ * maintained.
+ */
+ if (inflateReset(&png_ptr->zstream) == Z_OK)
{
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = text;
- *newlength = prefix_size + expanded_size;
- return; /* The success return! */
+ /* Because of the limit checks above we know that the new,
+ * expanded, size will fit in a size_t (let alone an
+ * png_alloc_size_t). Use png_malloc_base here to avoid an
+ * extra OOM message.
+ */
+ png_alloc_size_t new_size = *newlength;
+ png_alloc_size_t buffer_size = prefix_size + new_size +
+ (terminate != 0);
+ png_bytep text = png_voidcast(png_bytep, png_malloc_base(png_ptr,
+ buffer_size));
+
+ if (text != NULL)
+ {
+ ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/,
+ png_ptr->read_buffer + prefix_size, &lzsize,
+ text + prefix_size, newlength);
+
+ if (ret == Z_STREAM_END)
+ {
+ if (new_size == *newlength)
+ {
+ if (terminate)
+ text[prefix_size + *newlength] = 0;
+
+ if (prefix_size > 0)
+ memcpy(text, png_ptr->read_buffer, prefix_size);
+
+ {
+ png_bytep old_ptr = png_ptr->read_buffer;
+
+ png_ptr->read_buffer = text;
+ png_ptr->read_buffer_size = buffer_size;
+ text = old_ptr; /* freed below */
+ }
+ }
+
+ else
+ {
+ /* The size changed on the second read, there can be no
+ * guarantee that anything is correct at this point.
+ * The 'msg' pointer has been set to "unexpected end of
+ * LZ stream", which is fine, but return an error code
+ * that the caller won't accept.
+ */
+ ret = PNG_UNEXPECTED_ZLIB_RETURN;
+ }
+ }
+
+ else if (ret == Z_OK)
+ ret = PNG_UNEXPECTED_ZLIB_RETURN; /* for safety */
+
+ /* Free the text pointer (this is the old read_buffer on
+ * success)
+ */
+ png_free(png_ptr, text);
+
+ /* This really is very benign, but it's still an error because
+ * the extra space may otherwise be used as a Trojan Horse.
+ */
+ if (ret == Z_STREAM_END &&
+ chunklength - prefix_size != lzsize)
+ png_chunk_benign_error(png_ptr, "extra compressed data");
+ }
+
+ else
+ {
+ /* Out of memory allocating the buffer */
+ ret = Z_MEM_ERROR;
+ png_zstream_error(png_ptr, Z_MEM_ERROR);
+ }
}
- png_warning(png_ptr, "png_inflate logic error");
- png_free(png_ptr, text);
+ else
+ {
+ /* inflateReset failed, store the error message */
+ png_zstream_error(png_ptr, ret);
+
+ if (ret == Z_STREAM_END)
+ ret = PNG_UNEXPECTED_ZLIB_RETURN;
+ }
}
- else
- png_warning(png_ptr, "Not enough memory to decompress chunk");
+ else if (ret == Z_OK)
+ ret = PNG_UNEXPECTED_ZLIB_RETURN;
+
+ /* Release the claimed stream */
+ png_ptr->zowner = 0;
}
+
+ else /* the claim failed */ if (ret == Z_STREAM_END) /* impossible! */
+ ret = PNG_UNEXPECTED_ZLIB_RETURN;
+
+ return ret;
}
- else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */
+ else
{
- PNG_WARNING_PARAMETERS(p)
- png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, comp_type);
- png_formatted_warning(png_ptr, p, "Unknown zTXt compression type @1");
-
- /* The recovery is to simply drop the data. */
+ /* Application/configuration limits exceeded */
+ png_zstream_error(png_ptr, Z_MEM_ERROR);
+ return Z_MEM_ERROR;
}
+}
+#endif /* PNG_READ_COMPRESSED_TEXT_SUPPORTED */
- /* Generic error return - leave the prefix, delete the compressed
- * data, reallocate the chunkdata to remove the potentially large
- * amount of compressed data.
- */
+#ifdef PNG_READ_iCCP_SUPPORTED
+/* Perform a partial read and decompress, producing 'avail_out' bytes and
+ * reading from the current chunk as required.
+ */
+static int
+png_inflate_read(png_structrp png_ptr, png_bytep read_buffer, uInt read_size,
+ png_uint_32p chunk_bytes, png_bytep next_out, png_alloc_size_t *out_size,
+ int finish)
+{
+ if (png_ptr->zowner == png_ptr->chunk_name)
{
- png_charp text = (png_charp)png_malloc_warn(png_ptr, prefix_size + 1);
+ int ret;
+
+ /* next_in and avail_in must have been initialized by the caller. */
+ png_ptr->zstream.next_out = next_out;
+ png_ptr->zstream.avail_out = 0; /* set in the loop */
- if (text != NULL)
+ do
{
- if (prefix_size > 0)
- png_memcpy(text, png_ptr->chunkdata, prefix_size);
+ if (png_ptr->zstream.avail_in == 0)
+ {
+ if (read_size > *chunk_bytes)
+ read_size = (uInt)*chunk_bytes;
+ *chunk_bytes -= read_size;
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = text;
+ if (read_size > 0)
+ png_crc_read(png_ptr, read_buffer, read_size);
- /* This is an extra zero in the 'uncompressed' part. */
- *(png_ptr->chunkdata + prefix_size) = 0x00;
+ png_ptr->zstream.next_in = read_buffer;
+ png_ptr->zstream.avail_in = read_size;
+ }
+
+ if (png_ptr->zstream.avail_out == 0)
+ {
+ uInt avail = ZLIB_IO_MAX;
+ if (avail > *out_size)
+ avail = (uInt)*out_size;
+ *out_size -= avail;
+
+ png_ptr->zstream.avail_out = avail;
+ }
+
+ /* Use Z_SYNC_FLUSH when there is no more chunk data to ensure that all
+ * the available output is produced; this allows reading of truncated
+ * streams.
+ */
+ ret = inflate(&png_ptr->zstream,
+ *chunk_bytes > 0 ? Z_NO_FLUSH : (finish ? Z_FINISH : Z_SYNC_FLUSH));
}
- /* Ignore a malloc error here - it is safe. */
+ while (ret == Z_OK && (*out_size > 0 || png_ptr->zstream.avail_out > 0));
+
+ *out_size += png_ptr->zstream.avail_out;
+ png_ptr->zstream.avail_out = 0; /* Should not be required, but is safe */
+
+ /* Ensure the error message pointer is always set: */
+ png_zstream_error(png_ptr, ret);
+ return ret;
}
- *newlength = prefix_size;
+ else
+ {
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed");
+ return Z_STREAM_ERROR;
+ }
}
-#endif /* PNG_READ_COMPRESSED_TEXT_SUPPORTED */
+#endif
/* Read and check the IDHR chunk */
void /* PRIVATE */
-png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+png_handle_IHDR(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
png_byte buf[13];
png_uint_32 width, height;
png_debug(1, "in png_handle_IHDR");
if (png_ptr->mode & PNG_HAVE_IHDR)
- png_error(png_ptr, "Out of place IHDR");
+ png_chunk_error(png_ptr, "out of place");
/* Check the length */
if (length != 13)
- png_error(png_ptr, "Invalid IHDR chunk");
+ png_chunk_error(png_ptr, "invalid");
png_ptr->mode |= PNG_HAVE_IHDR;
/* Read and check the palette */
void /* PRIVATE */
-png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+png_handle_PLTE(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
png_color palette[PNG_MAX_PALETTE_LENGTH];
int num, i;
png_debug(1, "in png_handle_PLTE");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before PLTE");
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ /* Moved to before the 'after IDAT' check below because otherwise duplicate
+ * PLTE chunks are potentially ignored (the spec says there shall not be more
+ * than one PLTE, the error is not treated as benign, so this check trumps
+ * the requirement that PLTE appears before IDAT.)
+ */
+ else if (png_ptr->mode & PNG_HAVE_PLTE)
+ png_chunk_error(png_ptr, "duplicate");
else if (png_ptr->mode & PNG_HAVE_IDAT)
{
- png_warning(png_ptr, "Invalid PLTE after IDAT");
+ /* This is benign because the non-benign error happened before, when an
+ * IDAT was encountered in a color-mapped image with no PLTE.
+ */
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
return;
}
- else if (png_ptr->mode & PNG_HAVE_PLTE)
- png_error(png_ptr, "Duplicate PLTE chunk");
-
png_ptr->mode |= PNG_HAVE_PLTE;
- if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
+ if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR))
{
- png_warning(png_ptr,
- "Ignoring PLTE chunk in grayscale PNG");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "ignored in grayscale PNG");
return;
}
if (length > 3*PNG_MAX_PALETTE_LENGTH || length % 3)
{
+ png_crc_finish(png_ptr, length);
+
if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
- {
- png_warning(png_ptr, "Invalid palette chunk");
- png_crc_finish(png_ptr, length);
- return;
- }
+ png_chunk_benign_error(png_ptr, "invalid");
else
- {
- png_error(png_ptr, "Invalid palette chunk");
- }
+ png_chunk_error(png_ptr, "invalid");
+
+ return;
}
+ /* The cast is safe because 'length' is less than 3*PNG_MAX_PALETTE_LENGTH */
num = (int)length / 3;
#ifdef PNG_POINTER_INDEXING_SUPPORTED
* we have two options: an error abort, or a warning and we
* ignore the data in this chunk (which should be OK, since
* it's considered ancillary for a RGB or RGBA image).
+ *
+ * IMPLEMENTATION NOTE: this is only here because png_crc_finish uses the
+ * chunk type to determine whether to check the ancillary or the critical
+ * flags.
*/
if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE))
{
}
#endif
+ /* TODO: png_set_PLTE has the side effect of setting png_ptr->palette to its
+ * own copy of the palette. This has the side effect that when png_start_row
+ * is called (this happens after any call to png_read_update_info) the
+ * info_ptr palette gets changed. This is extremely unexpected and
+ * confusing.
+ *
+ * Fix this by not sharing the palette in this way.
+ */
png_set_PLTE(png_ptr, info_ptr, palette, num);
+ /* The three chunks, bKGD, hIST and tRNS *must* appear after PLTE and before
+ * IDAT. Prior to 1.6.0 this was not checked; instead the code merely
+ * checked the apparent validity of a tRNS chunk inserted before PLTE on a
+ * palette PNG. 1.6.0 attempts to rigorously follow the standard and
+ * therefore does a benign error if the erroneous condition is detected *and*
+ * cancels the tRNS if the benign error returns. The alternative is to
+ * amend the standard since it would be rather hypocritical of the standards
+ * maintainers to ignore it.
+ */
#ifdef PNG_READ_tRNS_SUPPORTED
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ if (png_ptr->num_trans > 0 ||
+ (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS) != 0))
{
- if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
- {
- if (png_ptr->num_trans > (png_uint_16)num)
- {
- png_warning(png_ptr, "Truncating incorrect tRNS chunk length");
- png_ptr->num_trans = (png_uint_16)num;
- }
+ /* Cancel this because otherwise it would be used if the transforms
+ * require it. Don't cancel the 'valid' flag because this would prevent
+ * detection of duplicate chunks.
+ */
+ png_ptr->num_trans = 0;
- if (info_ptr->num_trans > (png_uint_16)num)
- {
- png_warning(png_ptr, "Truncating incorrect info tRNS chunk length");
- info_ptr->num_trans = (png_uint_16)num;
- }
- }
+ if (info_ptr != NULL)
+ info_ptr->num_trans = 0;
+
+ png_chunk_benign_error(png_ptr, "tRNS must be after");
}
#endif
+#ifdef PNG_READ_hIST_SUPPORTED
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST) != 0)
+ png_chunk_benign_error(png_ptr, "hIST must be after");
+#endif
+
+#ifdef PNG_READ_bKGD_SUPPORTED
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD) != 0)
+ png_chunk_benign_error(png_ptr, "bKGD must be after");
+#endif
}
void /* PRIVATE */
-png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+png_handle_IEND(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
png_debug(1, "in png_handle_IEND");
if (!(png_ptr->mode & PNG_HAVE_IHDR) || !(png_ptr->mode & PNG_HAVE_IDAT))
- {
- png_error(png_ptr, "No image in file");
- }
+ png_chunk_error(png_ptr, "out of place");
png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND);
- if (length != 0)
- {
- png_warning(png_ptr, "Incorrect IEND chunk length");
- }
-
png_crc_finish(png_ptr, length);
- PNG_UNUSED(info_ptr) /* Quiet compiler warnings about unused info_ptr */
+ if (length != 0)
+ png_chunk_benign_error(png_ptr, "invalid");
+
+ PNG_UNUSED(info_ptr)
}
#ifdef PNG_READ_gAMA_SUPPORTED
void /* PRIVATE */
-png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+png_handle_gAMA(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
png_fixed_point igamma;
png_byte buf[4];
png_debug(1, "in png_handle_gAMA");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before gAMA");
+ png_chunk_error(png_ptr, "missing IHDR");
- else if (png_ptr->mode & PNG_HAVE_IDAT)
+ else if (png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE))
{
- png_warning(png_ptr, "Invalid gAMA after IDAT");
- png_crc_finish(png_ptr, length);
- return;
- }
-
- else if (png_ptr->mode & PNG_HAVE_PLTE)
- /* Should be an error, but we can cope with it */
- png_warning(png_ptr, "Out of place gAMA chunk");
-
- if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
-#ifdef PNG_READ_sRGB_SUPPORTED
- && !(info_ptr->valid & PNG_INFO_sRGB)
-#endif
- )
- {
- png_warning(png_ptr, "Duplicate gAMA chunk");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
return;
}
if (length != 4)
{
- png_warning(png_ptr, "Incorrect gAMA chunk length");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
return;
}
igamma = png_get_fixed_point(NULL, buf);
- /* Check for zero gamma or an error. */
- if (igamma <= 0)
- {
- png_warning(png_ptr,
- "Ignoring gAMA chunk with out of range gamma");
-
- return;
- }
-
-# ifdef PNG_READ_sRGB_SUPPORTED
- if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
- {
- if (PNG_OUT_OF_RANGE(igamma, 45500, 500))
- {
- PNG_WARNING_PARAMETERS(p)
- png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed, igamma);
- png_formatted_warning(png_ptr, p,
- "Ignoring incorrect gAMA value @1 when sRGB is also present");
- return;
- }
- }
-# endif /* PNG_READ_sRGB_SUPPORTED */
-
-# ifdef PNG_READ_GAMMA_SUPPORTED
- /* Gamma correction on read is supported. */
- png_ptr->gamma = igamma;
-# endif
- /* And set the 'info' structure members. */
- png_set_gAMA_fixed(png_ptr, info_ptr, igamma);
+ png_colorspace_set_gamma(png_ptr, &png_ptr->colorspace, igamma);
+ png_colorspace_sync(png_ptr, info_ptr);
}
#endif
#ifdef PNG_READ_sBIT_SUPPORTED
void /* PRIVATE */
-png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+png_handle_sBIT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
- png_size_t truelen;
+ unsigned int truelen;
png_byte buf[4];
png_debug(1, "in png_handle_sBIT");
buf[0] = buf[1] = buf[2] = buf[3] = 0;
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before sBIT");
+ png_chunk_error(png_ptr, "missing IHDR");
- else if (png_ptr->mode & PNG_HAVE_IDAT)
+ else if (png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE))
{
- png_warning(png_ptr, "Invalid sBIT after IDAT");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
return;
}
- else if (png_ptr->mode & PNG_HAVE_PLTE)
- {
- /* Should be an error, but we can cope with it */
- png_warning(png_ptr, "Out of place sBIT chunk");
- }
-
if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT))
{
- png_warning(png_ptr, "Duplicate sBIT chunk");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "duplicate");
return;
}
truelen = 3;
else
- truelen = (png_size_t)png_ptr->channels;
+ truelen = png_ptr->channels;
if (length != truelen || length > 4)
{
- png_warning(png_ptr, "Incorrect sBIT chunk length");
+ png_chunk_benign_error(png_ptr, "invalid");
png_crc_finish(png_ptr, length);
return;
}
#ifdef PNG_READ_cHRM_SUPPORTED
void /* PRIVATE */
-png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+png_handle_cHRM(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
png_byte buf[32];
- png_fixed_point x_white, y_white, x_red, y_red, x_green, y_green, x_blue,
- y_blue;
+ png_xy xy;
png_debug(1, "in png_handle_cHRM");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before cHRM");
+ png_chunk_error(png_ptr, "missing IHDR");
- else if (png_ptr->mode & PNG_HAVE_IDAT)
+ else if (png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE))
{
- png_warning(png_ptr, "Invalid cHRM after IDAT");
- png_crc_finish(png_ptr, length);
- return;
- }
-
- else if (png_ptr->mode & PNG_HAVE_PLTE)
- /* Should be an error, but we can cope with it */
- png_warning(png_ptr, "Out of place cHRM chunk");
-
- if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM)
-# ifdef PNG_READ_sRGB_SUPPORTED
- && !(info_ptr->valid & PNG_INFO_sRGB)
-# endif
- )
- {
- png_warning(png_ptr, "Duplicate cHRM chunk");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
return;
}
if (length != 32)
{
- png_warning(png_ptr, "Incorrect cHRM chunk length");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
return;
}
if (png_crc_finish(png_ptr, 0))
return;
- x_white = png_get_fixed_point(NULL, buf);
- y_white = png_get_fixed_point(NULL, buf + 4);
- x_red = png_get_fixed_point(NULL, buf + 8);
- y_red = png_get_fixed_point(NULL, buf + 12);
- x_green = png_get_fixed_point(NULL, buf + 16);
- y_green = png_get_fixed_point(NULL, buf + 20);
- x_blue = png_get_fixed_point(NULL, buf + 24);
- y_blue = png_get_fixed_point(NULL, buf + 28);
-
- if (x_white == PNG_FIXED_ERROR ||
- y_white == PNG_FIXED_ERROR ||
- x_red == PNG_FIXED_ERROR ||
- y_red == PNG_FIXED_ERROR ||
- x_green == PNG_FIXED_ERROR ||
- y_green == PNG_FIXED_ERROR ||
- x_blue == PNG_FIXED_ERROR ||
- y_blue == PNG_FIXED_ERROR)
- {
- png_warning(png_ptr, "Ignoring cHRM chunk with negative chromaticities");
+ xy.whitex = png_get_fixed_point(NULL, buf);
+ xy.whitey = png_get_fixed_point(NULL, buf + 4);
+ xy.redx = png_get_fixed_point(NULL, buf + 8);
+ xy.redy = png_get_fixed_point(NULL, buf + 12);
+ xy.greenx = png_get_fixed_point(NULL, buf + 16);
+ xy.greeny = png_get_fixed_point(NULL, buf + 20);
+ xy.bluex = png_get_fixed_point(NULL, buf + 24);
+ xy.bluey = png_get_fixed_point(NULL, buf + 28);
+
+ if (xy.whitex == PNG_FIXED_ERROR ||
+ xy.whitey == PNG_FIXED_ERROR ||
+ xy.redx == PNG_FIXED_ERROR ||
+ xy.redy == PNG_FIXED_ERROR ||
+ xy.greenx == PNG_FIXED_ERROR ||
+ xy.greeny == PNG_FIXED_ERROR ||
+ xy.bluex == PNG_FIXED_ERROR ||
+ xy.bluey == PNG_FIXED_ERROR)
+ {
+ png_chunk_benign_error(png_ptr, "invalid values");
return;
}
-#ifdef PNG_READ_sRGB_SUPPORTED
- if ((info_ptr != NULL) && (info_ptr->valid & PNG_INFO_sRGB))
- {
- if (PNG_OUT_OF_RANGE(x_white, 31270, 1000) ||
- PNG_OUT_OF_RANGE(y_white, 32900, 1000) ||
- PNG_OUT_OF_RANGE(x_red, 64000, 1000) ||
- PNG_OUT_OF_RANGE(y_red, 33000, 1000) ||
- PNG_OUT_OF_RANGE(x_green, 30000, 1000) ||
- PNG_OUT_OF_RANGE(y_green, 60000, 1000) ||
- PNG_OUT_OF_RANGE(x_blue, 15000, 1000) ||
- PNG_OUT_OF_RANGE(y_blue, 6000, 1000))
- {
- PNG_WARNING_PARAMETERS(p)
-
- png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed, x_white);
- png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_fixed, y_white);
- png_warning_parameter_signed(p, 3, PNG_NUMBER_FORMAT_fixed, x_red);
- png_warning_parameter_signed(p, 4, PNG_NUMBER_FORMAT_fixed, y_red);
- png_warning_parameter_signed(p, 5, PNG_NUMBER_FORMAT_fixed, x_green);
- png_warning_parameter_signed(p, 6, PNG_NUMBER_FORMAT_fixed, y_green);
- png_warning_parameter_signed(p, 7, PNG_NUMBER_FORMAT_fixed, x_blue);
- png_warning_parameter_signed(p, 8, PNG_NUMBER_FORMAT_fixed, y_blue);
-
- png_formatted_warning(png_ptr, p,
- "Ignoring incorrect cHRM white(@1,@2) r(@3,@4)g(@5,@6)b(@7,@8) "
- "when sRGB is also present");
- }
+ /* If a colorspace error has already been output skip this chunk */
+ if (png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID)
return;
- }
-#endif /* PNG_READ_sRGB_SUPPORTED */
-#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
- /* Store the _white values as default coefficients for the rgb to gray
- * operation if it is supported. Check if the transform is already set to
- * avoid destroying the transform values.
- */
- if (!png_ptr->rgb_to_gray_coefficients_set)
+ if (png_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM)
{
- /* png_set_background has not been called and we haven't seen an sRGB
- * chunk yet. Find the XYZ of the three end points.
- */
- png_XYZ XYZ;
- png_xy xy;
-
- xy.redx = x_red;
- xy.redy = y_red;
- xy.greenx = x_green;
- xy.greeny = y_green;
- xy.bluex = x_blue;
- xy.bluey = y_blue;
- xy.whitex = x_white;
- xy.whitey = y_white;
-
- if (png_XYZ_from_xy_checked(png_ptr, &XYZ, xy))
- {
- /* The success case, because XYZ_from_xy normalises to a reference
- * white Y of 1.0 we just need to scale the numbers. This should
- * always work just fine. It is an internal error if this overflows.
- */
- {
- png_fixed_point r, g, b;
- if (png_muldiv(&r, XYZ.redY, 32768, PNG_FP_1) &&
- r >= 0 && r <= 32768 &&
- png_muldiv(&g, XYZ.greenY, 32768, PNG_FP_1) &&
- g >= 0 && g <= 32768 &&
- png_muldiv(&b, XYZ.blueY, 32768, PNG_FP_1) &&
- b >= 0 && b <= 32768 &&
- r+g+b <= 32769)
- {
- /* We allow 0 coefficients here. r+g+b may be 32769 if two or
- * all of the coefficients were rounded up. Handle this by
- * reducing the *largest* coefficient by 1; this matches the
- * approach used for the default coefficients in pngrtran.c
- */
- int add = 0;
-
- if (r+g+b > 32768)
- add = -1;
- else if (r+g+b < 32768)
- add = 1;
-
- if (add != 0)
- {
- if (g >= r && g >= b)
- g += add;
- else if (r >= g && r >= b)
- r += add;
- else
- b += add;
- }
-
- /* Check for an internal error. */
- if (r+g+b != 32768)
- png_error(png_ptr,
- "internal error handling cHRM coefficients");
-
- png_ptr->rgb_to_gray_red_coeff = (png_uint_16)r;
- png_ptr->rgb_to_gray_green_coeff = (png_uint_16)g;
- }
-
- /* This is a png_error at present even though it could be ignored -
- * it should never happen, but it is important that if it does, the
- * bug is fixed.
- */
- else
- png_error(png_ptr, "internal error handling cHRM->XYZ");
- }
- }
+ png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID;
+ png_colorspace_sync(png_ptr, info_ptr);
+ png_chunk_benign_error(png_ptr, "duplicate");
+ return;
}
-#endif
- png_set_cHRM_fixed(png_ptr, info_ptr, x_white, y_white, x_red, y_red,
- x_green, y_green, x_blue, y_blue);
+ png_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM;
+ (void)png_colorspace_set_chromaticities(png_ptr, &png_ptr->colorspace, &xy,
+ 1/*prefer cHRM values*/);
+ png_colorspace_sync(png_ptr, info_ptr);
}
#endif
#ifdef PNG_READ_sRGB_SUPPORTED
-void /* PRIVATE */
-png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
-{
- int intent;
- png_byte buf[1];
-
- png_debug(1, "in png_handle_sRGB");
-
- if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before sRGB");
-
- else if (png_ptr->mode & PNG_HAVE_IDAT)
- {
- png_warning(png_ptr, "Invalid sRGB after IDAT");
- png_crc_finish(png_ptr, length);
- return;
- }
+void /* PRIVATE */
+png_handle_sRGB(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_byte intent;
- else if (png_ptr->mode & PNG_HAVE_PLTE)
- /* Should be an error, but we can cope with it */
- png_warning(png_ptr, "Out of place sRGB chunk");
+ png_debug(1, "in png_handle_sRGB");
- if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ else if (png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE))
{
- png_warning(png_ptr, "Duplicate sRGB chunk");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
return;
}
if (length != 1)
{
- png_warning(png_ptr, "Incorrect sRGB chunk length");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
return;
}
- png_crc_read(png_ptr, buf, 1);
+ png_crc_read(png_ptr, &intent, 1);
if (png_crc_finish(png_ptr, 0))
return;
- intent = buf[0];
-
- /* Check for bad intent */
- if (intent >= PNG_sRGB_INTENT_LAST)
- {
- png_warning(png_ptr, "Unknown sRGB intent");
+ /* If a colorspace error has already been output skip this chunk */
+ if (png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID)
return;
- }
-#if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
- if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA))
+ /* Only one sRGB or iCCP chunk is allowed, use the HAVE_INTENT flag to detect
+ * this.
+ */
+ if (png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_INTENT)
{
- if (PNG_OUT_OF_RANGE(info_ptr->gamma, 45500, 500))
- {
- PNG_WARNING_PARAMETERS(p)
-
- png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed,
- info_ptr->gamma);
-
- png_formatted_warning(png_ptr, p,
- "Ignoring incorrect gAMA value @1 when sRGB is also present");
- }
+ png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID;
+ png_colorspace_sync(png_ptr, info_ptr);
+ png_chunk_benign_error(png_ptr, "too many profiles");
+ return;
}
-#endif /* PNG_READ_gAMA_SUPPORTED */
-
-#ifdef PNG_READ_cHRM_SUPPORTED
- if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
- if (PNG_OUT_OF_RANGE(info_ptr->x_white, 31270, 1000) ||
- PNG_OUT_OF_RANGE(info_ptr->y_white, 32900, 1000) ||
- PNG_OUT_OF_RANGE(info_ptr->x_red, 64000, 1000) ||
- PNG_OUT_OF_RANGE(info_ptr->y_red, 33000, 1000) ||
- PNG_OUT_OF_RANGE(info_ptr->x_green, 30000, 1000) ||
- PNG_OUT_OF_RANGE(info_ptr->y_green, 60000, 1000) ||
- PNG_OUT_OF_RANGE(info_ptr->x_blue, 15000, 1000) ||
- PNG_OUT_OF_RANGE(info_ptr->y_blue, 6000, 1000))
- {
- png_warning(png_ptr,
- "Ignoring incorrect cHRM value when sRGB is also present");
- }
-#endif /* PNG_READ_cHRM_SUPPORTED */
-
- /* This is recorded for use when handling the cHRM chunk above. An sRGB
- * chunk unconditionally overwrites the coefficients for grayscale conversion
- * too.
- */
- png_ptr->is_sRGB = 1;
-
-# ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
- /* Don't overwrite user supplied values: */
- if (!png_ptr->rgb_to_gray_coefficients_set)
- {
- /* These numbers come from the sRGB specification (or, since one has to
- * pay much money to get a copy, the wikipedia sRGB page) the
- * chromaticity values quoted have been inverted to get the reverse
- * transformation from RGB to XYZ and the 'Y' coefficients scaled by
- * 32768 (then rounded).
- *
- * sRGB and ITU Rec-709 both truncate the values for the D65 white
- * point to four digits and, even though it actually stores five
- * digits, the PNG spec gives the truncated value.
- *
- * This means that when the chromaticities are converted back to XYZ
- * end points we end up with (6968,23435,2366), which, as described in
- * pngrtran.c, would overflow. If the five digit precision and up is
- * used we get, instead:
- *
- * 6968*R + 23435*G + 2365*B
- *
- * (Notice that this rounds the blue coefficient down, rather than the
- * choice used in pngrtran.c which is to round the green one down.)
- */
- png_ptr->rgb_to_gray_red_coeff = 6968; /* 0.212639005871510 */
- png_ptr->rgb_to_gray_green_coeff = 23434; /* 0.715168678767756 */
- /* png_ptr->rgb_to_gray_blue_coeff = 2366; 0.072192315360734 */
-
- /* The following keeps the cHRM chunk from destroying the
- * coefficients again in the event that it follows the sRGB chunk.
- */
- png_ptr->rgb_to_gray_coefficients_set = 1;
- }
-# endif
- png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent);
+ (void)png_colorspace_set_sRGB(png_ptr, &png_ptr->colorspace, intent);
+ png_colorspace_sync(png_ptr, info_ptr);
}
#endif /* PNG_READ_sRGB_SUPPORTED */
#ifdef PNG_READ_iCCP_SUPPORTED
void /* PRIVATE */
-png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
-/* Note: this does not properly handle chunks that are > 64K under DOS */
+png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+/* Note: this does not properly handle profiles that are > 64K under DOS */
{
- png_byte compression_type;
- png_bytep pC;
- png_charp profile;
- png_uint_32 skip = 0;
- png_uint_32 profile_size;
- png_alloc_size_t profile_length;
- png_size_t slength, prefix_length, data_length;
+ png_const_charp errmsg = NULL; /* error message output, or no error */
+ int finished = 0; /* crc checked */
png_debug(1, "in png_handle_iCCP");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before iCCP");
+ png_chunk_error(png_ptr, "missing IHDR");
- else if (png_ptr->mode & PNG_HAVE_IDAT)
+ else if (png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE))
{
- png_warning(png_ptr, "Invalid iCCP after IDAT");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
return;
}
- else if (png_ptr->mode & PNG_HAVE_PLTE)
- /* Should be an error, but we can cope with it */
- png_warning(png_ptr, "Out of place iCCP chunk");
-
- if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP))
+ /* Consistent with all the above colorspace handling an obviously *invalid*
+ * chunk is just ignored, so does not invalidate the color space. An
+ * alternative is to set the 'invalid' flags at the start of this routine
+ * and only clear them in they were not set before and all the tests pass.
+ * The minimum 'deflate' stream is assumed to be just the 2 byte header and 4
+ * byte checksum. The keyword must be one character and there is a
+ * terminator (0) byte and the compression method.
+ */
+ if (length < 9)
{
- png_warning(png_ptr, "Duplicate iCCP chunk");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "too short");
return;
}
-#ifdef PNG_MAX_MALLOC_64K
- if (length > (png_uint_32)65535L)
+ /* If a colorspace error has already been output skip this chunk */
+ if (png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID)
{
- png_warning(png_ptr, "iCCP chunk too large to fit in memory");
- skip = length - (png_uint_32)65535L;
- length = (png_uint_32)65535L;
+ png_crc_finish(png_ptr, length);
+ return;
}
-#endif
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
- slength = (png_size_t)length;
- png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
-
- if (png_crc_finish(png_ptr, skip))
+ /* Only one sRGB or iCCP chunk is allowed, use the HAVE_INTENT flag to detect
+ * this.
+ */
+ if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_INTENT) == 0)
{
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
- return;
- }
+ uInt read_length, keyword_length;
+ char keyword[81];
+
+ /* Find the keyword; the keyword plus separator and compression method
+ * bytes can be at most 81 characters long.
+ */
+ read_length = 81; /* maximum */
+ if (read_length > length)
+ read_length = (uInt)length;
- png_ptr->chunkdata[slength] = 0x00;
+ png_crc_read(png_ptr, (png_bytep)keyword, read_length);
+ length -= read_length;
- for (profile = png_ptr->chunkdata; *profile; profile++)
- /* Empty loop to find end of name */ ;
+ keyword_length = 0;
+ while (keyword_length < 80 && keyword_length < read_length &&
+ keyword[keyword_length] != 0)
+ ++keyword_length;
- ++profile;
+ /* TODO: make the keyword checking common */
+ if (keyword_length >= 1 && keyword_length <= 79)
+ {
+ /* We only understand '0' compression - deflate - so if we get a
+ * different value we can't safely decode the chunk.
+ */
+ if (keyword_length+1 < read_length &&
+ keyword[keyword_length+1] == PNG_COMPRESSION_TYPE_BASE)
+ {
+ read_length -= keyword_length+2;
- /* There should be at least one zero (the compression type byte)
- * following the separator, and we should be on it
- */
- if (profile >= png_ptr->chunkdata + slength - 1)
- {
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
- png_warning(png_ptr, "Malformed iCCP chunk");
- return;
- }
+ if (png_inflate_claim(png_ptr, png_iCCP,
+ png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN ? 15 : 0) == Z_OK)
+ {
+ Byte profile_header[132];
+ Byte local_buffer[PNG_INFLATE_BUF_SIZE];
+ png_alloc_size_t size = (sizeof profile_header);
- /* Compression_type should always be zero */
- compression_type = *profile++;
+ png_ptr->zstream.next_in = (Bytef*)keyword + (keyword_length+2);
+ png_ptr->zstream.avail_in = read_length;
+ (void)png_inflate_read(png_ptr, local_buffer,
+ (sizeof local_buffer), &length, profile_header, &size,
+ 0/*finish: don't, because the output is too small*/);
- if (compression_type)
- {
- png_warning(png_ptr, "Ignoring nonzero compression type in iCCP chunk");
- compression_type = 0x00; /* Reset it to zero (libpng-1.0.6 through 1.0.8
- wrote nonzero) */
- }
+ if (size == 0)
+ {
+ /* We have the ICC profile header; do the basic header checks.
+ */
+ const png_uint_32 profile_length =
+ png_get_uint_32(profile_header);
+
+ if (png_icc_check_length(png_ptr, &png_ptr->colorspace,
+ keyword, profile_length))
+ {
+ /* The length is apparently ok, so we can check the 132
+ * byte header.
+ */
+ if (png_icc_check_header(png_ptr, &png_ptr->colorspace,
+ keyword, profile_length, profile_header,
+ png_ptr->color_type))
+ {
+ /* Now read the tag table; a variable size buffer is
+ * needed at this point, allocate one for the whole
+ * profile. The header check has already validated
+ * that none of these stuff will overflow.
+ */
+ const png_uint_32 tag_count = png_get_uint_32(
+ profile_header+128);
+ png_bytep profile = png_read_buffer(png_ptr,
+ profile_length, 2/*silent*/);
+
+ if (profile != NULL)
+ {
+ memcpy(profile, profile_header,
+ (sizeof profile_header));
+
+ size = 12 * tag_count;
+
+ (void)png_inflate_read(png_ptr, local_buffer,
+ (sizeof local_buffer), &length,
+ profile + (sizeof profile_header), &size, 0);
+
+ /* Still expect a a buffer error because we expect
+ * there to be some tag data!
+ */
+ if (size == 0)
+ {
+ if (png_icc_check_tag_table(png_ptr,
+ &png_ptr->colorspace, keyword, profile_length,
+ profile))
+ {
+ /* The profile has been validated for basic
+ * security issues, so read the whole thing in.
+ */
+ size = profile_length - (sizeof profile_header)
+ - 12 * tag_count;
+
+ (void)png_inflate_read(png_ptr, local_buffer,
+ (sizeof local_buffer), &length,
+ profile + (sizeof profile_header) +
+ 12 * tag_count, &size, 1/*finish*/);
+
+ if (length > 0 && !(png_ptr->flags &
+ PNG_FLAG_BENIGN_ERRORS_WARN))
+ errmsg = "extra compressed data";
+
+ /* But otherwise allow extra data: */
+ else if (size == 0)
+ {
+ if (length > 0)
+ {
+ /* This can be handled completely, so
+ * keep going.
+ */
+ png_chunk_warning(png_ptr,
+ "extra compressed data");
+ }
+
+ png_crc_finish(png_ptr, length);
+ finished = 1;
+
+# ifdef PNG_sRGB_SUPPORTED
+ /* Check for a match against sRGB */
+ png_icc_set_sRGB(png_ptr,
+ &png_ptr->colorspace, profile,
+ png_ptr->zstream.adler);
+# endif
+
+ /* Steal the profile for info_ptr. */
+ if (info_ptr != NULL)
+ {
+ png_free_data(png_ptr, info_ptr,
+ PNG_FREE_ICCP, 0);
+
+ info_ptr->iccp_name = png_voidcast(char*,
+ png_malloc_base(png_ptr,
+ keyword_length+1));
+ if (info_ptr->iccp_name != NULL)
+ {
+ memcpy(info_ptr->iccp_name, keyword,
+ keyword_length+1);
+ info_ptr->iccp_proflen =
+ profile_length;
+ info_ptr->iccp_profile = profile;
+ png_ptr->read_buffer = NULL; /*steal*/
+ info_ptr->free_me |= PNG_FREE_ICCP;
+ info_ptr->valid |= PNG_INFO_iCCP;
+ }
+
+ else
+ {
+ png_ptr->colorspace.flags |=
+ PNG_COLORSPACE_INVALID;
+ errmsg = "out of memory";
+ }
+ }
+
+ /* else the profile remains in the read
+ * buffer which gets reused for subsequent
+ * chunks.
+ */
+
+ if (info_ptr != NULL)
+ png_colorspace_sync(png_ptr, info_ptr);
+
+ if (errmsg == NULL)
+ {
+ png_ptr->zowner = 0;
+ return;
+ }
+ }
+
+ else if (size > 0)
+ errmsg = "truncated";
+
+ else
+ errmsg = png_ptr->zstream.msg;
+ }
+
+ /* else png_icc_check_tag_table output an error */
+ }
+
+ else /* profile truncated */
+ errmsg = png_ptr->zstream.msg;
+ }
- prefix_length = profile - png_ptr->chunkdata;
- png_decompress_chunk(png_ptr, compression_type,
- slength, prefix_length, &data_length);
+ else
+ errmsg = "out of memory";
+ }
- profile_length = data_length - prefix_length;
+ /* else png_icc_check_header output an error */
+ }
- if (prefix_length > data_length || profile_length < 4)
- {
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
- png_warning(png_ptr, "Profile size field missing from iCCP chunk");
- return;
- }
+ /* else png_icc_check_length output an error */
+ }
- /* Check the profile_size recorded in the first 32 bits of the ICC profile */
- pC = (png_bytep)(png_ptr->chunkdata + prefix_length);
- profile_size = ((*(pC )) << 24) |
- ((*(pC + 1)) << 16) |
- ((*(pC + 2)) << 8) |
- ((*(pC + 3)) );
+ else /* profile truncated */
+ errmsg = png_ptr->zstream.msg;
- /* NOTE: the following guarantees that 'profile_length' fits into 32 bits,
- * because profile_size is a 32 bit value.
- */
- if (profile_size < profile_length)
- profile_length = profile_size;
+ /* Release the stream */
+ png_ptr->zowner = 0;
+ }
- /* And the following guarantees that profile_size == profile_length. */
- if (profile_size > profile_length)
- {
- PNG_WARNING_PARAMETERS(p)
+ else /* png_inflate_claim failed */
+ errmsg = png_ptr->zstream.msg;
+ }
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
+ else
+ errmsg = "bad compression method"; /* or missing */
+ }
- png_warning_parameter_unsigned(p, 1, PNG_NUMBER_FORMAT_u, profile_size);
- png_warning_parameter_unsigned(p, 2, PNG_NUMBER_FORMAT_u, profile_length);
- png_formatted_warning(png_ptr, p,
- "Ignoring iCCP chunk with declared size = @1 and actual length = @2");
- return;
+ else
+ errmsg = "bad keyword";
}
- png_set_iCCP(png_ptr, info_ptr, png_ptr->chunkdata,
- compression_type, (png_bytep)png_ptr->chunkdata + prefix_length,
- profile_size);
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
+ else
+ errmsg = "too many profiles";
+
+ /* Failure: the reason is in 'errmsg' */
+ if (!finished)
+ png_crc_finish(png_ptr, length);
+
+ png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID;
+ png_colorspace_sync(png_ptr, info_ptr);
+ if (errmsg != NULL) /* else already output */
+ png_chunk_benign_error(png_ptr, errmsg);
}
#endif /* PNG_READ_iCCP_SUPPORTED */
#ifdef PNG_READ_sPLT_SUPPORTED
void /* PRIVATE */
-png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+png_handle_sPLT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
/* Note: this does not properly handle chunks that are > 64K under DOS */
{
- png_bytep entry_start;
+ png_bytep entry_start, buffer;
png_sPLT_t new_palette;
png_sPLT_entryp pp;
png_uint_32 data_length;
int entry_size, i;
png_uint_32 skip = 0;
- png_size_t slength;
png_uint_32 dl;
png_size_t max_dl;
png_debug(1, "in png_handle_sPLT");
#ifdef PNG_USER_LIMITS_SUPPORTED
-
if (png_ptr->user_chunk_cache_max != 0)
{
if (png_ptr->user_chunk_cache_max == 1)
#endif
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before sPLT");
+ png_chunk_error(png_ptr, "missing IHDR");
else if (png_ptr->mode & PNG_HAVE_IDAT)
{
- png_warning(png_ptr, "Invalid sPLT after IDAT");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
return;
}
#ifdef PNG_MAX_MALLOC_64K
- if (length > (png_uint_32)65535L)
+ if (length > 65535U)
{
- png_warning(png_ptr, "sPLT chunk too large to fit in memory");
- skip = length - (png_uint_32)65535L;
- length = (png_uint_32)65535L;
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "too large to fit in memory");
+ return;
}
#endif
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
+ buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/);
+ if (buffer == NULL)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of memory");
+ return;
+ }
+
/* WARNING: this may break if size_t is less than 32 bits; it is assumed
* that the PNG_MAX_MALLOC_64K test is enabled in this case, but this is a
* potential breakage point if the types in pngconf.h aren't exactly right.
*/
- slength = (png_size_t)length;
- png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+ png_crc_read(png_ptr, buffer, length);
if (png_crc_finish(png_ptr, skip))
- {
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
return;
- }
- png_ptr->chunkdata[slength] = 0x00;
+ buffer[length] = 0;
- for (entry_start = (png_bytep)png_ptr->chunkdata; *entry_start;
- entry_start++)
+ for (entry_start = buffer; *entry_start; entry_start++)
/* Empty loop to find end of name */ ;
++entry_start;
/* A sample depth should follow the separator, and we should be on it */
- if (entry_start > (png_bytep)png_ptr->chunkdata + slength - 2)
+ if (entry_start > buffer + length - 2)
{
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
png_warning(png_ptr, "malformed sPLT chunk");
return;
}
new_palette.depth = *entry_start++;
entry_size = (new_palette.depth == 8 ? 6 : 10);
/* This must fit in a png_uint_32 because it is derived from the original
- * chunk data length (and use 'length', not 'slength' here for clarity -
- * they are guaranteed to be the same, see the tests above.)
+ * chunk data length.
*/
- data_length = length - (png_uint_32)(entry_start -
- (png_bytep)png_ptr->chunkdata);
+ data_length = length - (png_uint_32)(entry_start - buffer);
/* Integrity-check the data length */
if (data_length % entry_size)
{
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
png_warning(png_ptr, "sPLT chunk has bad length");
return;
}
dl = (png_int_32)(data_length / entry_size);
- max_dl = PNG_SIZE_MAX / png_sizeof(png_sPLT_entry);
+ max_dl = PNG_SIZE_MAX / (sizeof (png_sPLT_entry));
if (dl > max_dl)
{
new_palette.nentries = (png_int_32)(data_length / entry_size);
new_palette.entries = (png_sPLT_entryp)png_malloc_warn(
- png_ptr, new_palette.nentries * png_sizeof(png_sPLT_entry));
+ png_ptr, new_palette.nentries * (sizeof (png_sPLT_entry)));
if (new_palette.entries == NULL)
{
#endif
/* Discard all chunk data except the name and stash that */
- new_palette.name = png_ptr->chunkdata;
+ new_palette.name = (png_charp)buffer;
png_set_sPLT(png_ptr, info_ptr, &new_palette, 1);
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
png_free(png_ptr, new_palette.entries);
}
#endif /* PNG_READ_sPLT_SUPPORTED */
#ifdef PNG_READ_tRNS_SUPPORTED
void /* PRIVATE */
-png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+png_handle_tRNS(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
png_byte readbuf[PNG_MAX_PALETTE_LENGTH];
png_debug(1, "in png_handle_tRNS");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before tRNS");
+ png_chunk_error(png_ptr, "missing IHDR");
else if (png_ptr->mode & PNG_HAVE_IDAT)
{
- png_warning(png_ptr, "Invalid tRNS after IDAT");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
return;
}
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
{
- png_warning(png_ptr, "Duplicate tRNS chunk");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "duplicate");
return;
}
if (length != 2)
{
- png_warning(png_ptr, "Incorrect tRNS chunk length");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
return;
}
if (length != 6)
{
- png_warning(png_ptr, "Incorrect tRNS chunk length");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
return;
}
- png_crc_read(png_ptr, buf, (png_size_t)length);
+ png_crc_read(png_ptr, buf, length);
png_ptr->num_trans = 1;
png_ptr->trans_color.red = png_get_uint_16(buf);
png_ptr->trans_color.green = png_get_uint_16(buf + 2);
{
if (!(png_ptr->mode & PNG_HAVE_PLTE))
{
- /* Should be an error, but we can cope with it. */
- png_warning(png_ptr, "Missing PLTE before tRNS");
- }
-
- if (length > (png_uint_32)png_ptr->num_palette ||
- length > PNG_MAX_PALETTE_LENGTH)
- {
- png_warning(png_ptr, "Incorrect tRNS chunk length");
+ /* TODO: is this actually an error in the ISO spec? */
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
return;
}
- if (length == 0)
+ if (length > png_ptr->num_palette || length > PNG_MAX_PALETTE_LENGTH ||
+ length == 0)
{
- png_warning(png_ptr, "Zero length tRNS chunk");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
return;
}
- png_crc_read(png_ptr, readbuf, (png_size_t)length);
+ png_crc_read(png_ptr, readbuf, length);
png_ptr->num_trans = (png_uint_16)length;
}
else
{
- png_warning(png_ptr, "tRNS chunk not allowed with alpha channel");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid with alpha channel");
return;
}
return;
}
+ /* TODO: this is a horrible side effect in the palette case because the
+ * png_struct ends up with a pointer to the tRNS buffer owned by the
+ * png_info. Fix this.
+ */
png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans,
&(png_ptr->trans_color));
}
#ifdef PNG_READ_bKGD_SUPPORTED
void /* PRIVATE */
-png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+png_handle_bKGD(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
- png_size_t truelen;
+ unsigned int truelen;
png_byte buf[6];
png_color_16 background;
png_debug(1, "in png_handle_bKGD");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before bKGD");
-
- else if (png_ptr->mode & PNG_HAVE_IDAT)
- {
- png_warning(png_ptr, "Invalid bKGD after IDAT");
- png_crc_finish(png_ptr, length);
- return;
- }
+ png_chunk_error(png_ptr, "missing IHDR");
- else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
- !(png_ptr->mode & PNG_HAVE_PLTE))
+ else if ((png_ptr->mode & PNG_HAVE_IDAT) ||
+ (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+ !(png_ptr->mode & PNG_HAVE_PLTE)))
{
- png_warning(png_ptr, "Missing PLTE before bKGD");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
return;
}
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD))
{
- png_warning(png_ptr, "Duplicate bKGD chunk");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "duplicate");
return;
}
if (length != truelen)
{
- png_warning(png_ptr, "Incorrect bKGD chunk length");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
return;
}
{
if (buf[0] >= info_ptr->num_palette)
{
- png_warning(png_ptr, "Incorrect bKGD chunk index value");
+ png_chunk_benign_error(png_ptr, "invalid index");
return;
}
#ifdef PNG_READ_hIST_SUPPORTED
void /* PRIVATE */
-png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+png_handle_hIST(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
unsigned int num, i;
png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH];
png_debug(1, "in png_handle_hIST");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before hIST");
-
- else if (png_ptr->mode & PNG_HAVE_IDAT)
- {
- png_warning(png_ptr, "Invalid hIST after IDAT");
- png_crc_finish(png_ptr, length);
- return;
- }
+ png_chunk_error(png_ptr, "missing IHDR");
- else if (!(png_ptr->mode & PNG_HAVE_PLTE))
+ else if ((png_ptr->mode & PNG_HAVE_IDAT) || !(png_ptr->mode & PNG_HAVE_PLTE))
{
- png_warning(png_ptr, "Missing PLTE before hIST");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
return;
}
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST))
{
- png_warning(png_ptr, "Duplicate hIST chunk");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "duplicate");
return;
}
num = length / 2 ;
- if (num != (unsigned int)png_ptr->num_palette || num >
- (unsigned int)PNG_MAX_PALETTE_LENGTH)
+ if (num != png_ptr->num_palette || num > PNG_MAX_PALETTE_LENGTH)
{
- png_warning(png_ptr, "Incorrect hIST chunk length");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
return;
}
#ifdef PNG_READ_pHYs_SUPPORTED
void /* PRIVATE */
-png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+png_handle_pHYs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
png_byte buf[9];
png_uint_32 res_x, res_y;
png_debug(1, "in png_handle_pHYs");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before pHYs");
+ png_chunk_error(png_ptr, "missing IHDR");
else if (png_ptr->mode & PNG_HAVE_IDAT)
{
- png_warning(png_ptr, "Invalid pHYs after IDAT");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
return;
}
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
{
- png_warning(png_ptr, "Duplicate pHYs chunk");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "duplicate");
return;
}
if (length != 9)
{
- png_warning(png_ptr, "Incorrect pHYs chunk length");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
return;
}
#ifdef PNG_READ_oFFs_SUPPORTED
void /* PRIVATE */
-png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+png_handle_oFFs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
png_byte buf[9];
png_int_32 offset_x, offset_y;
png_debug(1, "in png_handle_oFFs");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before oFFs");
+ png_chunk_error(png_ptr, "missing IHDR");
else if (png_ptr->mode & PNG_HAVE_IDAT)
{
- png_warning(png_ptr, "Invalid oFFs after IDAT");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
return;
}
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
{
- png_warning(png_ptr, "Duplicate oFFs chunk");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "duplicate");
return;
}
if (length != 9)
{
- png_warning(png_ptr, "Incorrect oFFs chunk length");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
return;
}
#ifdef PNG_READ_pCAL_SUPPORTED
/* Read the pCAL chunk (described in the PNG Extensions document) */
void /* PRIVATE */
-png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+png_handle_pCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
png_int_32 X0, X1;
png_byte type, nparams;
- png_charp buf, units, endptr;
+ png_bytep buffer, buf, units, endptr;
png_charpp params;
- png_size_t slength;
int i;
png_debug(1, "in png_handle_pCAL");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before pCAL");
+ png_chunk_error(png_ptr, "missing IHDR");
else if (png_ptr->mode & PNG_HAVE_IDAT)
{
- png_warning(png_ptr, "Invalid pCAL after IDAT");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
return;
}
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL))
{
- png_warning(png_ptr, "Duplicate pCAL chunk");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "duplicate");
return;
}
png_debug1(2, "Allocating and reading pCAL chunk data (%u bytes)",
length + 1);
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
- if (png_ptr->chunkdata == NULL)
+ buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/);
+
+ if (buffer == NULL)
{
- png_warning(png_ptr, "No memory for pCAL purpose");
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of memory");
return;
}
- slength = (png_size_t)length;
- png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+ png_crc_read(png_ptr, buffer, length);
if (png_crc_finish(png_ptr, 0))
- {
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
return;
- }
- png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */
+ buffer[length] = 0; /* Null terminate the last string */
png_debug(3, "Finding end of pCAL purpose string");
- for (buf = png_ptr->chunkdata; *buf; buf++)
+ for (buf = buffer; *buf; buf++)
/* Empty loop */ ;
- endptr = png_ptr->chunkdata + slength;
+ endptr = buffer + length;
/* We need to have at least 12 bytes after the purpose string
* in order to get the parameter information.
*/
if (endptr <= buf + 12)
{
- png_warning(png_ptr, "Invalid pCAL data");
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
+ png_chunk_benign_error(png_ptr, "invalid");
return;
}
(type == PNG_EQUATION_ARBITRARY && nparams != 3) ||
(type == PNG_EQUATION_HYPERBOLIC && nparams != 4))
{
- png_warning(png_ptr, "Invalid pCAL parameters for equation type");
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
+ png_chunk_benign_error(png_ptr, "invalid parameter count");
return;
}
else if (type >= PNG_EQUATION_LAST)
{
- png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
+ png_chunk_benign_error(png_ptr, "unrecognized equation type");
}
for (buf = units; *buf; buf++)
png_debug(3, "Allocating pCAL parameters array");
- params = (png_charpp)png_malloc_warn(png_ptr,
- (png_size_t)(nparams * png_sizeof(png_charp)));
+ params = png_voidcast(png_charpp, png_malloc_warn(png_ptr,
+ nparams * (sizeof (png_charp))));
if (params == NULL)
{
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
- png_warning(png_ptr, "No memory for pCAL params");
+ png_chunk_benign_error(png_ptr, "out of memory");
return;
}
/* Get pointers to the start of each parameter string. */
- for (i = 0; i < (int)nparams; i++)
+ for (i = 0; i < nparams; i++)
{
buf++; /* Skip the null string terminator from previous parameter. */
png_debug1(3, "Reading pCAL parameter %d", i);
- for (params[i] = buf; buf <= endptr && *buf != 0x00; buf++)
+ for (params[i] = (png_charp)buf; buf <= endptr && *buf != 0; buf++)
/* Empty loop to move past each parameter string */ ;
/* Make sure we haven't run out of data yet */
if (buf > endptr)
{
- png_warning(png_ptr, "Invalid pCAL data");
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
png_free(png_ptr, params);
+ png_chunk_benign_error(png_ptr, "invalid data");
return;
}
}
- png_set_pCAL(png_ptr, info_ptr, png_ptr->chunkdata, X0, X1, type, nparams,
- units, params);
+ png_set_pCAL(png_ptr, info_ptr, (png_charp)buffer, X0, X1, type, nparams,
+ (png_charp)units, params);
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
png_free(png_ptr, params);
}
#endif
#ifdef PNG_READ_sCAL_SUPPORTED
/* Read the sCAL chunk */
void /* PRIVATE */
-png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+png_handle_sCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
- png_size_t slength, i;
+ png_bytep buffer;
+ png_size_t i;
int state;
png_debug(1, "in png_handle_sCAL");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before sCAL");
+ png_chunk_error(png_ptr, "missing IHDR");
else if (png_ptr->mode & PNG_HAVE_IDAT)
{
- png_warning(png_ptr, "Invalid sCAL after IDAT");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
return;
}
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL))
{
- png_warning(png_ptr, "Duplicate sCAL chunk");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "duplicate");
return;
}
/* Need unit type, width, \0, height: minimum 4 bytes */
else if (length < 4)
{
- png_warning(png_ptr, "sCAL chunk too short");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
return;
}
png_debug1(2, "Allocating and reading sCAL chunk data (%u bytes)",
length + 1);
- png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+ buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/);
- if (png_ptr->chunkdata == NULL)
+ if (buffer == NULL)
{
- png_warning(png_ptr, "Out of memory while processing sCAL chunk");
+ png_chunk_benign_error(png_ptr, "out of memory");
png_crc_finish(png_ptr, length);
return;
}
- slength = (png_size_t)length;
- png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
- png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */
+ png_crc_read(png_ptr, buffer, length);
+ buffer[length] = 0; /* Null terminate the last string */
if (png_crc_finish(png_ptr, 0))
- {
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
return;
- }
/* Validate the unit. */
- if (png_ptr->chunkdata[0] != 1 && png_ptr->chunkdata[0] != 2)
+ if (buffer[0] != 1 && buffer[0] != 2)
{
- png_warning(png_ptr, "Invalid sCAL ignored: invalid unit");
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
+ png_chunk_benign_error(png_ptr, "invalid unit");
return;
}
i = 1;
state = 0;
- if (!png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) ||
- i >= slength || png_ptr->chunkdata[i++] != 0)
- png_warning(png_ptr, "Invalid sCAL chunk ignored: bad width format");
+ if (!png_check_fp_number((png_const_charp)buffer, length, &state, &i) ||
+ i >= length || buffer[i++] != 0)
+ png_chunk_benign_error(png_ptr, "bad width format");
else if (!PNG_FP_IS_POSITIVE(state))
- png_warning(png_ptr, "Invalid sCAL chunk ignored: non-positive width");
+ png_chunk_benign_error(png_ptr, "non-positive width");
else
{
png_size_t heighti = i;
state = 0;
- if (!png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) ||
- i != slength)
- png_warning(png_ptr, "Invalid sCAL chunk ignored: bad height format");
+ if (!png_check_fp_number((png_const_charp)buffer, length, &state, &i) ||
+ i != length)
+ png_chunk_benign_error(png_ptr, "bad height format");
else if (!PNG_FP_IS_POSITIVE(state))
- png_warning(png_ptr,
- "Invalid sCAL chunk ignored: non-positive height");
+ png_chunk_benign_error(png_ptr, "non-positive height");
else
/* This is the (only) success case. */
- png_set_sCAL_s(png_ptr, info_ptr, png_ptr->chunkdata[0],
- png_ptr->chunkdata+1, png_ptr->chunkdata+heighti);
+ png_set_sCAL_s(png_ptr, info_ptr, buffer[0],
+ (png_charp)buffer+1, (png_charp)buffer+heighti);
}
-
- /* Clean up - just free the temporarily allocated buffer. */
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
}
#endif
#ifdef PNG_READ_tIME_SUPPORTED
void /* PRIVATE */
-png_handle_tIME(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+png_handle_tIME(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
png_byte buf[7];
png_time mod_time;
png_debug(1, "in png_handle_tIME");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Out of place tIME chunk");
+ png_chunk_error(png_ptr, "missing IHDR");
else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME))
{
- png_warning(png_ptr, "Duplicate tIME chunk");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "duplicate");
return;
}
if (length != 7)
{
- png_warning(png_ptr, "Incorrect tIME chunk length");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
return;
}
#ifdef PNG_READ_tEXt_SUPPORTED
/* Note: this does not properly handle chunks that are > 64K under DOS */
void /* PRIVATE */
-png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+png_handle_tEXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
- png_textp text_ptr;
+ png_text text_info;
+ png_bytep buffer;
png_charp key;
png_charp text;
png_uint_32 skip = 0;
- png_size_t slength;
- int ret;
png_debug(1, "in png_handle_tEXt");
if (--png_ptr->user_chunk_cache_max == 1)
{
- png_warning(png_ptr, "No space in chunk cache for tEXt");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "no space in chunk cache");
return;
}
}
#endif
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before tEXt");
+ png_chunk_error(png_ptr, "missing IHDR");
if (png_ptr->mode & PNG_HAVE_IDAT)
png_ptr->mode |= PNG_AFTER_IDAT;
#ifdef PNG_MAX_MALLOC_64K
- if (length > (png_uint_32)65535L)
+ if (length > 65535U)
{
- png_warning(png_ptr, "tEXt chunk too large to fit in memory");
- skip = length - (png_uint_32)65535L;
- length = (png_uint_32)65535L;
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "too large to fit in memory");
+ return;
}
#endif
- png_free(png_ptr, png_ptr->chunkdata);
-
- png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+ buffer = png_read_buffer(png_ptr, length+1, 1/*warn*/);
- if (png_ptr->chunkdata == NULL)
+ if (buffer == NULL)
{
- png_warning(png_ptr, "No memory to process text chunk");
+ png_chunk_benign_error(png_ptr, "out of memory");
return;
}
- slength = (png_size_t)length;
- png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+ png_crc_read(png_ptr, buffer, length);
if (png_crc_finish(png_ptr, skip))
- {
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
return;
- }
- key = png_ptr->chunkdata;
-
- key[slength] = 0x00;
+ key = (png_charp)buffer;
+ key[length] = 0;
for (text = key; *text; text++)
/* Empty loop to find end of key */ ;
- if (text != key + slength)
+ if (text != key + length)
text++;
- text_ptr = (png_textp)png_malloc_warn(png_ptr,
- png_sizeof(png_text));
-
- if (text_ptr == NULL)
- {
- png_warning(png_ptr, "Not enough memory to process text chunk");
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
- return;
- }
-
- text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
- text_ptr->key = key;
- text_ptr->lang = NULL;
- text_ptr->lang_key = NULL;
- text_ptr->itxt_length = 0;
- text_ptr->text = text;
- text_ptr->text_length = png_strlen(text);
+ text_info.compression = PNG_TEXT_COMPRESSION_NONE;
+ text_info.key = key;
+ text_info.lang = NULL;
+ text_info.lang_key = NULL;
+ text_info.itxt_length = 0;
+ text_info.text = text;
+ text_info.text_length = strlen(text);
- ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
-
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
- png_free(png_ptr, text_ptr);
-
- if (ret)
+ if (png_set_text_2(png_ptr, info_ptr, &text_info, 1))
png_warning(png_ptr, "Insufficient memory to process text chunk");
}
#endif
#ifdef PNG_READ_zTXt_SUPPORTED
/* Note: this does not correctly handle chunks that are > 64K under DOS */
void /* PRIVATE */
-png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+png_handle_zTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
- png_textp text_ptr;
- png_charp text;
- int comp_type;
- int ret;
- png_size_t slength, prefix_len, data_len;
+ png_const_charp errmsg = NULL;
+ png_bytep buffer;
+ png_uint_32 keyword_length;
png_debug(1, "in png_handle_zTXt");
if (--png_ptr->user_chunk_cache_max == 1)
{
- png_warning(png_ptr, "No space in chunk cache for zTXt");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "no space in chunk cache");
return;
}
}
#endif
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before zTXt");
+ png_chunk_error(png_ptr, "missing IHDR");
if (png_ptr->mode & PNG_HAVE_IDAT)
png_ptr->mode |= PNG_AFTER_IDAT;
-#ifdef PNG_MAX_MALLOC_64K
- /* We will no doubt have problems with chunks even half this size, but
- * there is no hard and fast rule to tell us where to stop.
- */
- if (length > (png_uint_32)65535L)
- {
- png_warning(png_ptr, "zTXt chunk too large to fit in memory");
- png_crc_finish(png_ptr, length);
- return;
- }
-#endif
-
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+ buffer = png_read_buffer(png_ptr, length, 2/*silent*/);
- if (png_ptr->chunkdata == NULL)
+ if (buffer == NULL)
{
- png_warning(png_ptr, "Out of memory processing zTXt chunk");
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of memory");
return;
}
- slength = (png_size_t)length;
- png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+ png_crc_read(png_ptr, buffer, length);
if (png_crc_finish(png_ptr, 0))
- {
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
return;
- }
- png_ptr->chunkdata[slength] = 0x00;
+ /* TODO: also check that the keyword contents match the spec! */
+ for (keyword_length = 0;
+ keyword_length < length && buffer[keyword_length] != 0;
+ ++keyword_length)
+ /* Empty loop to find end of name */ ;
- for (text = png_ptr->chunkdata; *text; text++)
- /* Empty loop */ ;
+ if (keyword_length > 79 || keyword_length < 1)
+ errmsg = "bad keyword";
- /* zTXt must have some text after the chunkdataword */
- if (text >= png_ptr->chunkdata + slength - 2)
- {
- png_warning(png_ptr, "Truncated zTXt chunk");
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
- return;
- }
+ /* zTXt must have some LZ data after the keyword, although it may expand to
+ * zero bytes; we need a '\0' at the end of the keyword, the compression type
+ * then the LZ data:
+ */
+ else if (keyword_length + 3 > length)
+ errmsg = "truncated";
+
+ else if (buffer[keyword_length+1] != PNG_COMPRESSION_TYPE_BASE)
+ errmsg = "unknown compression type";
else
{
- comp_type = *(++text);
-
- if (comp_type != PNG_TEXT_COMPRESSION_zTXt)
- {
- png_warning(png_ptr, "Unknown compression type in zTXt chunk");
- comp_type = PNG_TEXT_COMPRESSION_zTXt;
- }
-
- text++; /* Skip the compression_method byte */
- }
+ png_alloc_size_t uncompressed_length = PNG_SIZE_MAX;
- prefix_len = text - png_ptr->chunkdata;
-
- png_decompress_chunk(png_ptr, comp_type,
- (png_size_t)length, prefix_len, &data_len);
+ /* TODO: at present png_decompress_chunk imposes a single application
+ * level memory limit, this should be split to different values for iCCP
+ * and text chunks.
+ */
+ if (png_decompress_chunk(png_ptr, length, keyword_length+2,
+ &uncompressed_length, 1/*terminate*/) == Z_STREAM_END)
+ {
+ png_text text;
- text_ptr = (png_textp)png_malloc_warn(png_ptr,
- png_sizeof(png_text));
+ /* It worked; png_ptr->read_buffer now looks like a tEXt chunk except
+ * for the extra compression type byte and the fact that it isn't
+ * necessarily '\0' terminated.
+ */
+ buffer = png_ptr->read_buffer;
+ buffer[uncompressed_length+(keyword_length+2)] = 0;
+
+ text.compression = PNG_TEXT_COMPRESSION_zTXt;
+ text.key = (png_charp)buffer;
+ text.text = (png_charp)(buffer + keyword_length+2);
+ text.text_length = uncompressed_length;
+ text.itxt_length = 0;
+ text.lang = NULL;
+ text.lang_key = NULL;
+
+ if (png_set_text_2(png_ptr, info_ptr, &text, 1))
+ errmsg = "insufficient memory";
+ }
- if (text_ptr == NULL)
- {
- png_warning(png_ptr, "Not enough memory to process zTXt chunk");
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
- return;
+ else
+ errmsg = png_ptr->zstream.msg;
}
- text_ptr->compression = comp_type;
- text_ptr->key = png_ptr->chunkdata;
- text_ptr->lang = NULL;
- text_ptr->lang_key = NULL;
- text_ptr->itxt_length = 0;
- text_ptr->text = png_ptr->chunkdata + prefix_len;
- text_ptr->text_length = data_len;
-
- ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
-
- png_free(png_ptr, text_ptr);
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
-
- if (ret)
- png_error(png_ptr, "Insufficient memory to store zTXt chunk");
+ if (errmsg != NULL)
+ png_chunk_benign_error(png_ptr, errmsg);
}
#endif
#ifdef PNG_READ_iTXt_SUPPORTED
/* Note: this does not correctly handle chunks that are > 64K under DOS */
void /* PRIVATE */
-png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+png_handle_iTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
- png_textp text_ptr;
- png_charp key, lang, text, lang_key;
- int comp_flag;
- int comp_type = 0;
- int ret;
- png_size_t slength, prefix_len, data_len;
+ png_const_charp errmsg = NULL;
+ png_bytep buffer;
+ png_uint_32 prefix_length;
png_debug(1, "in png_handle_iTXt");
if (--png_ptr->user_chunk_cache_max == 1)
{
- png_warning(png_ptr, "No space in chunk cache for iTXt");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "no space in chunk cache");
return;
}
}
#endif
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before iTXt");
+ png_chunk_error(png_ptr, "missing IHDR");
if (png_ptr->mode & PNG_HAVE_IDAT)
png_ptr->mode |= PNG_AFTER_IDAT;
-#ifdef PNG_MAX_MALLOC_64K
- /* We will no doubt have problems with chunks even half this size, but
- * there is no hard and fast rule to tell us where to stop.
- */
- if (length > (png_uint_32)65535L)
- {
- png_warning(png_ptr, "iTXt chunk too large to fit in memory");
- png_crc_finish(png_ptr, length);
- return;
- }
-#endif
-
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+ buffer = png_read_buffer(png_ptr, length+1, 1/*warn*/);
- if (png_ptr->chunkdata == NULL)
+ if (buffer == NULL)
{
- png_warning(png_ptr, "No memory to process iTXt chunk");
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of memory");
return;
}
- slength = (png_size_t)length;
- png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
+ png_crc_read(png_ptr, buffer, length);
if (png_crc_finish(png_ptr, 0))
- {
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
return;
- }
- png_ptr->chunkdata[slength] = 0x00;
-
- for (lang = png_ptr->chunkdata; *lang; lang++)
+ /* First the keyword. */
+ for (prefix_length=0;
+ prefix_length < length && buffer[prefix_length] != 0;
+ ++prefix_length)
/* Empty loop */ ;
- lang++; /* Skip NUL separator */
+ /* Perform a basic check on the keyword length here. */
+ if (prefix_length > 79 || prefix_length < 1)
+ errmsg = "bad keyword";
- /* iTXt must have a language tag (possibly empty), two compression bytes,
- * translated keyword (possibly empty), and possibly some text after the
- * keyword
+ /* Expect keyword, compression flag, compression type, language, translated
+ * keyword (both may be empty but are 0 terminated) then the text, which may
+ * be empty.
*/
+ else if (prefix_length + 5 > length)
+ errmsg = "truncated";
- if (lang >= png_ptr->chunkdata + slength - 3)
+ else if (buffer[prefix_length+1] == 0 ||
+ (buffer[prefix_length+1] == 1 &&
+ buffer[prefix_length+2] == PNG_COMPRESSION_TYPE_BASE))
{
- png_warning(png_ptr, "Truncated iTXt chunk");
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
- return;
- }
+ int compressed = buffer[prefix_length+1] != 0;
+ png_uint_32 language_offset, translated_keyword_offset;
+ png_alloc_size_t uncompressed_length = 0;
- else
- {
- comp_flag = *lang++;
- comp_type = *lang++;
- }
+ /* Now the language tag */
+ prefix_length += 3;
+ language_offset = prefix_length;
- for (lang_key = lang; *lang_key; lang_key++)
- /* Empty loop */ ;
+ for (; prefix_length < length && buffer[prefix_length] != 0;
+ ++prefix_length)
+ /* Empty loop */ ;
- lang_key++; /* Skip NUL separator */
+ /* WARNING: the length may be invalid here, this is checked below. */
+ translated_keyword_offset = ++prefix_length;
- if (lang_key >= png_ptr->chunkdata + slength)
- {
- png_warning(png_ptr, "Truncated iTXt chunk");
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
- return;
- }
+ for (; prefix_length < length && buffer[prefix_length] != 0;
+ ++prefix_length)
+ /* Empty loop */ ;
- for (text = lang_key; *text; text++)
- /* Empty loop */ ;
+ /* prefix_length should now be at the trailing '\0' of the translated
+ * keyword, but it may already be over the end. None of this arithmetic
+ * can overflow because chunks are at most 2^31 bytes long, but on 16-bit
+ * systems the available allocaton may overflow.
+ */
+ ++prefix_length;
- text++; /* Skip NUL separator */
+ if (!compressed && prefix_length <= length)
+ uncompressed_length = length - prefix_length;
- if (text >= png_ptr->chunkdata + slength)
- {
- png_warning(png_ptr, "Malformed iTXt chunk");
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
- return;
- }
+ else if (compressed && prefix_length < length)
+ {
+ uncompressed_length = PNG_SIZE_MAX;
- prefix_len = text - png_ptr->chunkdata;
+ /* TODO: at present png_decompress_chunk imposes a single application
+ * level memory limit, this should be split to different values for
+ * iCCP and text chunks.
+ */
+ if (png_decompress_chunk(png_ptr, length, prefix_length,
+ &uncompressed_length, 1/*terminate*/) == Z_STREAM_END)
+ buffer = png_ptr->read_buffer;
- key=png_ptr->chunkdata;
+ else
+ errmsg = png_ptr->zstream.msg;
+ }
- if (comp_flag)
- png_decompress_chunk(png_ptr, comp_type,
- (size_t)length, prefix_len, &data_len);
+ else
+ errmsg = "truncated";
- else
- data_len = png_strlen(png_ptr->chunkdata + prefix_len);
+ if (errmsg == NULL)
+ {
+ png_text text;
- text_ptr = (png_textp)png_malloc_warn(png_ptr,
- png_sizeof(png_text));
+ buffer[uncompressed_length+prefix_length] = 0;
- if (text_ptr == NULL)
- {
- png_warning(png_ptr, "Not enough memory to process iTXt chunk");
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
- return;
- }
+ if (compressed)
+ text.compression = PNG_ITXT_COMPRESSION_NONE;
+
+ else
+ text.compression = PNG_ITXT_COMPRESSION_zTXt;
- text_ptr->compression = (int)comp_flag + 1;
- text_ptr->lang_key = png_ptr->chunkdata + (lang_key - key);
- text_ptr->lang = png_ptr->chunkdata + (lang - key);
- text_ptr->itxt_length = data_len;
- text_ptr->text_length = 0;
- text_ptr->key = png_ptr->chunkdata;
- text_ptr->text = png_ptr->chunkdata + prefix_len;
+ text.key = (png_charp)buffer;
+ text.lang = (png_charp)buffer + language_offset;
+ text.lang_key = (png_charp)buffer + translated_keyword_offset;
+ text.text = (png_charp)buffer + prefix_length;
+ text.text_length = 0;
+ text.itxt_length = uncompressed_length;
- ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+ if (png_set_text_2(png_ptr, info_ptr, &text, 1))
+ errmsg = "insufficient memory";
+ }
+ }
- png_free(png_ptr, text_ptr);
- png_free(png_ptr, png_ptr->chunkdata);
- png_ptr->chunkdata = NULL;
+ else
+ errmsg = "bad compression info";
- if (ret)
- png_error(png_ptr, "Insufficient memory to store iTXt chunk");
+ if (errmsg != NULL)
+ png_chunk_benign_error(png_ptr, errmsg);
}
#endif
-/* This function is called when we haven't found a handler for a
- * chunk. If there isn't a problem with the chunk itself (ie bad
- * chunk name, CRC, or a critical chunk), the chunk is silently ignored
- * -- unless the PNG_FLAG_UNKNOWN_CHUNKS_SUPPORTED flag is on in which
- * case it will be saved away to be written out later.
- */
-void /* PRIVATE */
-png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+/* Utility function for png_handle_unknown; set up png_ptr::unknown_chunk */
+static int
+png_cache_unknown_chunk(png_structrp png_ptr, png_uint_32 length)
{
- png_uint_32 skip = 0;
+ png_alloc_size_t limit = PNG_SIZE_MAX;
- png_debug(1, "in png_handle_unknown");
+ if (png_ptr->unknown_chunk.data != NULL)
+ {
+ png_free(png_ptr, png_ptr->unknown_chunk.data);
+ png_ptr->unknown_chunk.data = NULL;
+ }
-#ifdef PNG_USER_LIMITS_SUPPORTED
- if (png_ptr->user_chunk_cache_max != 0)
+# ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
+ if (png_ptr->user_chunk_malloc_max > 0 &&
+ png_ptr->user_chunk_malloc_max < limit)
+ limit = png_ptr->user_chunk_malloc_max;
+
+# elif PNG_USER_CHUNK_MALLOC_MAX > 0
+ if (PNG_USER_CHUNK_MALLOC_MAX < limit)
+ limit = PNG_USER_CHUNK_MALLOC_MAX;
+# endif
+
+ if (length <= limit)
{
- if (png_ptr->user_chunk_cache_max == 1)
- {
- png_crc_finish(png_ptr, length);
- return;
- }
+ PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name);
+ /* The following is safe because of the PNG_SIZE_MAX init above */
+ png_ptr->unknown_chunk.size = (png_size_t)length/*SAFE*/;
+ /* 'mode' is a flag array, only the bottom four bits matter here */
+ png_ptr->unknown_chunk.location = (png_byte)png_ptr->mode/*SAFE*/;
- if (--png_ptr->user_chunk_cache_max == 1)
+ if (length == 0)
+ png_ptr->unknown_chunk.data = NULL;
+
+ else
{
- png_warning(png_ptr, "No space in chunk cache for unknown chunk");
- png_crc_finish(png_ptr, length);
- return;
+ /* Do a 'warn' here - it is handled below. */
+ png_ptr->unknown_chunk.data = png_voidcast(png_bytep,
+ png_malloc_warn(png_ptr, length));
}
}
-#endif
- if (png_ptr->mode & PNG_HAVE_IDAT)
+ if (png_ptr->unknown_chunk.data == NULL && length > 0)
{
- if (png_ptr->chunk_name != png_IDAT)
- png_ptr->mode |= PNG_AFTER_IDAT;
+ /* This is benign because we clean up correctly */
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "unknown chunk exceeds memory limits");
+ return 0;
}
- if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
+ else
{
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
- if (png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name) !=
- PNG_HANDLE_CHUNK_ALWAYS
-#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
- && png_ptr->read_user_chunk_fn == NULL
-#endif
- )
-#endif
- png_chunk_error(png_ptr, "unknown critical chunk");
+ if (length > 0)
+ png_crc_read(png_ptr, png_ptr->unknown_chunk.data, length);
+ png_crc_finish(png_ptr, 0);
+ return 1;
}
+}
+#endif /* PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */
+
+/* Handle an unknown, or known but disabled, chunk */
+void /* PRIVATE */
+png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
+ png_uint_32 length, int keep)
+{
+ int handled = 0; /* the chunk was handled */
+
+ png_debug(1, "in png_handle_unknown");
+
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+ /* NOTE: this code is based on the code in libpng-1.4.12 except for fixing
+ * the bug which meant that setting a non-default behavior for a specific
+ * chunk would be ignored (the default was always used unless a user
+ * callback was installed).
+ *
+ * 'keep' is the value from the png_chunk_unknown_handling, the setting for
+ * this specific chunk_name, if PNG_HANDLE_AS_UNKNOWN_SUPPORTED, if not it
+ * will always be PNG_HANDLE_CHUNK_AS_DEFAULT and it needs to be set here.
+ * This is just an optimization to avoid multiple calls to the lookup
+ * function.
+ */
+# ifndef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+# ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+ keep = png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name);
+# endif
+# endif
-#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
- if ((png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
-#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
- || (png_ptr->read_user_chunk_fn != NULL)
-#endif
- )
- {
-#ifdef PNG_MAX_MALLOC_64K
- if (length > 65535)
+ /* One of the following methods will read the chunk or skip it (at least one
+ * of these is always defined because this is the only way to switch on
+ * PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
+ */
+# ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+ /* The user callback takes precedence over the chunk keep value, but the
+ * keep value is still required to validate a save of a critical chunk.
+ */
+ if (png_ptr->read_user_chunk_fn != NULL)
{
- png_warning(png_ptr, "unknown chunk too large to fit in memory");
- skip = length - 65535;
- length = 65535;
- }
-#endif
+ if (png_cache_unknown_chunk(png_ptr, length))
+ {
+ /* Callback to user unknown chunk handler */
+ int ret = (*(png_ptr->read_user_chunk_fn))(png_ptr,
+ &png_ptr->unknown_chunk);
+
+ /* ret is:
+ * negative: An error occured, png_chunk_error will be called.
+ * zero: The chunk was not handled, the chunk will be discarded
+ * unless png_set_keep_unknown_chunks has been used to set
+ * a 'keep' behavior for this particular chunk, in which
+ * case that will be used. A critical chunk will cause an
+ * error at this point unless it is to be saved.
+ * positive: The chunk was handled, libpng will ignore/discard it.
+ */
+ if (ret < 0)
+ png_chunk_error(png_ptr, "error in user chunk");
- /* TODO: this code is very close to the unknown handling in pngpread.c,
- * maybe it can be put into a common utility routine?
- * png_struct::unknown_chunk is just used as a temporary variable, along
- * with the data into which the chunk is read. These can be eliminated.
- */
- PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name);
- png_ptr->unknown_chunk.size = (png_size_t)length;
+ else if (ret == 0)
+ {
+ /* If the keep value is 'default' or 'never' override it, but
+ * still error out on critical chunks unless the keep value is
+ * 'always' While this is weird it is the behavior in 1.4.12.
+ * A possible improvement would be to obey the value set for the
+ * chunk, but this would be an API change that would probably
+ * damage some applications.
+ *
+ * The png_app_warning below catches the case that matters, where
+ * the application has not set specific save or ignore for this
+ * chunk or global save or ignore.
+ */
+ if (keep < PNG_HANDLE_CHUNK_IF_SAFE)
+ {
+# ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+ if (png_ptr->unknown_default < PNG_HANDLE_CHUNK_IF_SAFE)
+ {
+ png_chunk_warning(png_ptr, "Saving unknown chunk:");
+ png_app_warning(png_ptr,
+ "forcing save of an unhandled chunk;"
+ " please call png_set_keep_unknown_chunks");
+ /* with keep = PNG_HANDLE_CHUNK_IF_SAFE */
+ }
+# endif
+ keep = PNG_HANDLE_CHUNK_IF_SAFE;
+ }
+ }
- if (length == 0)
- png_ptr->unknown_chunk.data = NULL;
+ else /* chunk was handled */
+ {
+ handled = 1;
+ /* Critical chunks can be safely discarded at this point. */
+ keep = PNG_HANDLE_CHUNK_NEVER;
+ }
+ }
+
+ else
+ keep = PNG_HANDLE_CHUNK_NEVER; /* insufficient memory */
+ }
else
+ /* Use the SAVE_UNKNOWN_CHUNKS code or skip the chunk */
+# endif /* PNG_READ_USER_CHUNKS_SUPPORTED */
+
+# ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
{
- png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length);
- png_crc_read(png_ptr, png_ptr->unknown_chunk.data, length);
+ /* keep is currently just the per-chunk setting, if there was no
+ * setting change it to the global default now (not that this may
+ * still be AS_DEFAULT) then obtain the cache of the chunk if required,
+ * if not simply skip the chunk.
+ */
+ if (keep == PNG_HANDLE_CHUNK_AS_DEFAULT)
+ keep = png_ptr->unknown_default;
+
+ if (keep == PNG_HANDLE_CHUNK_ALWAYS ||
+ (keep == PNG_HANDLE_CHUNK_IF_SAFE &&
+ PNG_CHUNK_ANCILLARY(png_ptr->chunk_name)))
+ {
+ if (!png_cache_unknown_chunk(png_ptr, length))
+ keep = PNG_HANDLE_CHUNK_NEVER;
+ }
+
+ else
+ png_crc_finish(png_ptr, length);
}
+# else
+# ifndef PNG_READ_USER_CHUNKS_SUPPORTED
+# error no method to support READ_UNKNOWN_CHUNKS
+# endif
-#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
- if (png_ptr->read_user_chunk_fn != NULL)
{
- /* Callback to user unknown chunk handler */
- int ret;
-
- ret = (*(png_ptr->read_user_chunk_fn))
- (png_ptr, &png_ptr->unknown_chunk);
+ /* If here there is no read callback pointer set and no support is
+ * compiled in to just save the unknown chunks, so simply skip this
+ * chunk. If 'keep' is something other than AS_DEFAULT or NEVER then
+ * the app has erroneously asked for unknown chunk saving when there
+ * is no support.
+ */
+ if (keep > PNG_HANDLE_CHUNK_NEVER)
+ png_app_error(png_ptr, "no unknown chunk support available");
- if (ret < 0)
- png_chunk_error(png_ptr, "error in user chunk");
+ png_crc_finish(png_ptr, length);
+ }
+# endif
- if (ret == 0)
+# ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+ /* Now store the chunk in the chunk list if appropriate, and if the limits
+ * permit it.
+ */
+ if (keep == PNG_HANDLE_CHUNK_ALWAYS ||
+ (keep == PNG_HANDLE_CHUNK_IF_SAFE &&
+ PNG_CHUNK_ANCILLARY(png_ptr->chunk_name)))
+ {
+# ifdef PNG_USER_LIMITS_SUPPORTED
+ switch (png_ptr->user_chunk_cache_max)
{
- if (PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
- {
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
- if (png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name) !=
- PNG_HANDLE_CHUNK_ALWAYS)
-#endif
- png_chunk_error(png_ptr, "unknown critical chunk");
- }
+ case 2:
+ png_ptr->user_chunk_cache_max = 1;
+ png_chunk_benign_error(png_ptr, "no space in chunk cache");
+ /* FALL THROUGH */
+ case 1:
+ /* NOTE: prior to 1.6.0 this case resulted in an unknown critical
+ * chunk being skipped, now there will be a hard error below.
+ */
+ break;
- png_set_unknown_chunks(png_ptr, info_ptr,
- &png_ptr->unknown_chunk, 1);
+ default: /* not at limit */
+ --(png_ptr->user_chunk_cache_max);
+ /* FALL THROUGH */
+ case 0: /* no limit */
+# endif /* PNG_USER_LIMITS_SUPPORTED */
+ /* Here when the limit isn't reached or when limits are compiled
+ * out; store the chunk.
+ */
+ png_set_unknown_chunks(png_ptr, info_ptr,
+ &png_ptr->unknown_chunk, 1);
+ handled = 1;
+# ifdef PNG_USER_LIMITS_SUPPORTED
+ break;
}
+# endif
}
+# else /* no store support! */
+ PNG_UNUSED(info_ptr)
+# error untested code (reading unknown chunks with no store support)
+# endif
- else
-#endif
- png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
-
+ /* Regardless of the error handling below the cached data (if any) can be
+ * freed now. Notice that the data is not freed if there is a png_error, but
+ * it will be freed by destroy_read_struct.
+ */
+ if (png_ptr->unknown_chunk.data != NULL)
png_free(png_ptr, png_ptr->unknown_chunk.data);
- png_ptr->unknown_chunk.data = NULL;
- }
-
- else
-#endif
- skip = length;
+ png_ptr->unknown_chunk.data = NULL;
- png_crc_finish(png_ptr, skip);
+#else /* !PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */
+ /* There is no support to read an unknown chunk, so just skip it. */
+ png_crc_finish(png_ptr, length);
+ PNG_UNUSED(info_ptr)
+ PNG_UNUSED(keep)
+#endif /* !PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */
-#ifndef PNG_READ_USER_CHUNKS_SUPPORTED
- PNG_UNUSED(info_ptr) /* Quiet compiler warnings about unused info_ptr */
-#endif
+ /* Check for unhandled critical chunks */
+ if (!handled && PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
+ png_chunk_error(png_ptr, "unhandled critical chunk");
}
/* This function is called to verify that a chunk name is valid.
*/
void /* PRIVATE */
-png_check_chunk_name(png_structp png_ptr, png_uint_32 chunk_name)
+png_check_chunk_name(png_structrp png_ptr, png_uint_32 chunk_name)
{
int i;
}
}
-/* Combines the row recently read in with the existing pixels in the
- * row. This routine takes care of alpha and transparency if requested.
- * This routine also handles the two methods of progressive display
- * of interlaced images, depending on the mask value.
- * The mask value describes which pixels are to be combined with
- * the row. The pattern always repeats every 8 pixels, so just 8
- * bits are needed. A one indicates the pixel is to be combined,
- * a zero indicates the pixel is to be skipped. This is in addition
- * to any alpha or transparency value associated with the pixel. If
- * you want all pixels to be combined, pass 0xff (255) in mask.
+/* Combines the row recently read in with the existing pixels in the row. This
+ * routine takes care of alpha and transparency if requested. This routine also
+ * handles the two methods of progressive display of interlaced images,
+ * depending on the 'display' value; if 'display' is true then the whole row
+ * (dp) is filled from the start by replicating the available pixels. If
+ * 'display' is false only those pixels present in the pass are filled in.
*/
-
void /* PRIVATE */
-png_combine_row(png_structp png_ptr, png_bytep dp, int display)
+png_combine_row(png_const_structrp png_ptr, png_bytep dp, int display)
{
unsigned int pixel_depth = png_ptr->transformed_pixel_depth;
png_const_bytep sp = png_ptr->row_buf + 1;
/* end_mask is now the bits to *keep* from the destination row */
}
- /* For non-interlaced images this reduces to a png_memcpy(). A png_memcpy()
+ /* For non-interlaced images this reduces to a memcpy(). A memcpy()
* will also happen if interlacing isn't supported or if the application
* does not call png_set_interlace_handling(). In the latter cases the
* caller just gets a sequence of the unexpanded rows from each interlace
if (pixel_depth < 8)
{
- /* For pixel depths up to 4-bpp the 8-pixel mask can be expanded to fit
+ /* For pixel depths up to 4 bpp the 8-pixel mask can be expanded to fit
* into 32 bits, then a single loop over the bytes using the four byte
* values in the 32-bit mask can be used. For the 'display' option the
* expanded mask may also not require any masking within a byte. To
*
* The 'regular' case requires a mask for each of the first 6 passes,
* the 'display' case does a copy for the even passes in the range
- * 0..6. This has already been handled in the tst above.
+ * 0..6. This has already been handled in the test above.
*
* The masks are arranged as four bytes with the first byte to use in
* the lowest bits (little-endian) regardless of the order (PACKSWAP or
*
* NOTE: the whole of this logic depends on the caller of this function
* only calling it on rows appropriate to the pass. This function only
- * understands the 'x' logic, the 'y' logic is handled by the caller.
+ * understands the 'x' logic; the 'y' logic is handled by the caller.
*
* The following defines allow generation of compile time constant bit
* masks for each pixel depth and each possibility of swapped or not
* the compiler even though it isn't used. Microsoft Visual C (various
* versions) and the Intel C compiler are known to do this. To avoid
* this the following macros are used in 1.5.6. This is a temporary
- * solution to avoid destablizing the code during the release process.
+ * solution to avoid destabilizing the code during the release process.
*/
# if PNG_USE_COMPILE_TIME_MASKS
# define PNG_LSR(x,s) ((x)>>((s) & 0x1f))
#if PNG_USE_COMPILE_TIME_MASKS
/* Utility macros to construct all the masks for a depth/swap
* combination. The 's' parameter says whether the format is PNG
- * (big endian bytes) or not. Only the three odd numbered passes are
+ * (big endian bytes) or not. Only the three odd-numbered passes are
* required for the display/block algorithm.
*/
# define S_MASKS(d,s) { S_MASK(0,d,s), S_MASK(1,d,s), S_MASK(2,d,s),\
/* Hence the pre-compiled masks indexed by PACKSWAP (or not), depth and
* then pass:
*/
- static PNG_CONST png_uint_32 row_mask[2/*PACKSWAP*/][3/*depth*/][6] = {
+ static PNG_CONST png_uint_32 row_mask[2/*PACKSWAP*/][3/*depth*/][6] =
+ {
/* Little-endian byte masks for PACKSWAP */
{ S_MASKS(1,0), S_MASKS(2,0), S_MASKS(4,0) },
/* Normal (big-endian byte) masks - PNG format */
/* display_mask has only three entries for the odd passes, so index by
* pass>>1.
*/
- static PNG_CONST png_uint_32 display_mask[2][3][3] = {
+ static PNG_CONST png_uint_32 display_mask[2][3][3] =
+ {
/* Little-endian byte masks for PACKSWAP */
{ B_MASKS(1,0), B_MASKS(2,0), B_MASKS(4,0) },
/* Normal (big-endian byte) masks - PNG format */
/* Check for double byte alignment and, if possible, use a
* 16-bit copy. Don't attempt this for narrow images - ones that
* are less than an interlace panel wide. Don't attempt it for
- * wide bytes-to-copy either - use the png_memcpy there.
+ * wide bytes_to_copy either - use the memcpy there.
*/
- if (bytes_to_copy < 16 /*else use png_memcpy*/ &&
+ if (bytes_to_copy < 16 /*else use memcpy*/ &&
png_isaligned(dp, png_uint_16) &&
png_isaligned(sp, png_uint_16) &&
- bytes_to_copy % sizeof (png_uint_16) == 0 &&
- bytes_to_jump % sizeof (png_uint_16) == 0)
+ bytes_to_copy % (sizeof (png_uint_16)) == 0 &&
+ bytes_to_jump % (sizeof (png_uint_16)) == 0)
{
/* Everything is aligned for png_uint_16 copies, but try for
* png_uint_32 first.
*/
if (png_isaligned(dp, png_uint_32) &&
png_isaligned(sp, png_uint_32) &&
- bytes_to_copy % sizeof (png_uint_32) == 0 &&
- bytes_to_jump % sizeof (png_uint_32) == 0)
+ bytes_to_copy % (sizeof (png_uint_32)) == 0 &&
+ bytes_to_jump % (sizeof (png_uint_32)) == 0)
{
- png_uint_32p dp32 = (png_uint_32p)dp;
- png_const_uint_32p sp32 = (png_const_uint_32p)sp;
- unsigned int skip = (bytes_to_jump-bytes_to_copy) /
- sizeof (png_uint_32);
+ png_uint_32p dp32 = png_aligncast(png_uint_32p,dp);
+ png_const_uint_32p sp32 = png_aligncastconst(
+ png_const_uint_32p, sp);
+ size_t skip = (bytes_to_jump-bytes_to_copy) /
+ (sizeof (png_uint_32));
do
{
do
{
*dp32++ = *sp32++;
- c -= sizeof (png_uint_32);
+ c -= (sizeof (png_uint_32));
}
while (c > 0);
*/
else
{
- png_uint_16p dp16 = (png_uint_16p)dp;
- png_const_uint_16p sp16 = (png_const_uint_16p)sp;
- unsigned int skip = (bytes_to_jump-bytes_to_copy) /
- sizeof (png_uint_16);
+ png_uint_16p dp16 = png_aligncast(png_uint_16p, dp);
+ png_const_uint_16p sp16 = png_aligncastconst(
+ png_const_uint_16p, sp);
+ size_t skip = (bytes_to_jump-bytes_to_copy) /
+ (sizeof (png_uint_16));
do
{
do
{
*dp16++ = *sp16++;
- c -= sizeof (png_uint_16);
+ c -= (sizeof (png_uint_16));
}
while (c > 0);
}
#endif /* PNG_ALIGN_ code */
- /* The true default - use a png_memcpy: */
+ /* The true default - use a memcpy: */
for (;;)
{
- png_memcpy(dp, sp, bytes_to_copy);
+ memcpy(dp, sp, bytes_to_copy);
if (row_width <= bytes_to_jump)
return;
else
#endif
- /* If here then the switch above wasn't used so just png_memcpy the whole row
+ /* If here then the switch above wasn't used so just memcpy the whole row
* from the temporary row buffer (notice that this overwrites the end of the
* destination row if it is a partial byte.)
*/
- png_memcpy(dp, sp, PNG_ROWBYTES(pixel_depth, row_width));
+ memcpy(dp, sp, PNG_ROWBYTES(pixel_depth, row_width));
/* Restore the overwritten bits from the last byte if necessary. */
if (end_ptr != NULL)
v = (png_byte)((*sp >> sshift) & 0x01);
for (j = 0; j < jstop; j++)
{
- *dp &= (png_byte)((0x7f7f >> (7 - dshift)) & 0xff);
- *dp |= (png_byte)(v << dshift);
+ unsigned int tmp = *dp & (0x7f7f >> (7 - dshift));
+ tmp |= v << dshift;
+ *dp = (png_byte)(tmp & 0xff);
if (dshift == s_end)
{
v = (png_byte)((*sp >> sshift) & 0x03);
for (j = 0; j < jstop; j++)
{
- *dp &= (png_byte)((0x3f3f >> (6 - dshift)) & 0xff);
- *dp |= (png_byte)(v << dshift);
+ unsigned int tmp = *dp & (0x3f3f >> (6 - dshift));
+ tmp |= v << dshift;
+ *dp = (png_byte)(tmp & 0xff);
if (dshift == s_end)
{
for (j = 0; j < jstop; j++)
{
- *dp &= (png_byte)((0xf0f >> (4 - dshift)) & 0xff);
- *dp |= (png_byte)(v << dshift);
+ unsigned int tmp = *dp & (0xf0f >> (4 - dshift));
+ tmp |= v << dshift;
+ *dp = (png_byte)(tmp & 0xff);
if (dshift == s_end)
{
png_byte v[8];
int j;
- png_memcpy(v, sp, pixel_bytes);
+ memcpy(v, sp, pixel_bytes);
for (j = 0; j < jstop; j++)
{
- png_memcpy(dp, v, pixel_bytes);
+ memcpy(dp, v, pixel_bytes);
dp -= pixel_bytes;
}
}
#endif /* PNG_READ_INTERLACING_SUPPORTED */
-/* 1.5.6: Changed to just take a png_row_info (not png_ptr) and to ignore bad
- * adaptive filter bytes.
- */
+static void
+png_read_filter_row_sub(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ png_size_t i;
+ png_size_t istop = row_info->rowbytes;
+ unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
+ png_bytep rp = row + bpp;
+
+ PNG_UNUSED(prev_row)
+
+ for (i = bpp; i < istop; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff);
+ rp++;
+ }
+}
+
+static void
+png_read_filter_row_up(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ png_size_t i;
+ png_size_t istop = row_info->rowbytes;
+ png_bytep rp = row;
+ png_const_bytep pp = prev_row;
+
+ for (i = 0; i < istop; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
+ rp++;
+ }
+}
+
+static void
+png_read_filter_row_avg(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ png_size_t i;
+ png_bytep rp = row;
+ png_const_bytep pp = prev_row;
+ unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
+ png_size_t istop = row_info->rowbytes - bpp;
+
+ for (i = 0; i < bpp; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) +
+ ((int)(*pp++) / 2 )) & 0xff);
+
+ rp++;
+ }
+
+ for (i = 0; i < istop; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) +
+ (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
+
+ rp++;
+ }
+}
+
+static void
+png_read_filter_row_paeth_1byte_pixel(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ png_bytep rp_end = row + row_info->rowbytes;
+ int a, c;
+
+ /* First pixel/byte */
+ c = *prev_row++;
+ a = *row + c;
+ *row++ = (png_byte)a;
+
+ /* Remainder */
+ while (row < rp_end)
+ {
+ int b, pa, pb, pc, p;
+
+ a &= 0xff; /* From previous iteration or start */
+ b = *prev_row++;
+
+ p = b - c;
+ pc = a - c;
+
+# ifdef PNG_USE_ABS
+ pa = abs(p);
+ pb = abs(pc);
+ pc = abs(p + pc);
+# else
+ pa = p < 0 ? -p : p;
+ pb = pc < 0 ? -pc : pc;
+ pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+# endif
+
+ /* Find the best predictor, the least of pa, pb, pc favoring the earlier
+ * ones in the case of a tie.
+ */
+ if (pb < pa) pa = pb, a = b;
+ if (pc < pa) a = c;
+
+ /* Calculate the current pixel in a, and move the previous row pixel to c
+ * for the next time round the loop
+ */
+ c = b;
+ a += *row;
+ *row++ = (png_byte)a;
+ }
+}
+
+static void
+png_read_filter_row_paeth_multibyte_pixel(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ int bpp = (row_info->pixel_depth + 7) >> 3;
+ png_bytep rp_end = row + bpp;
+
+ /* Process the first pixel in the row completely (this is the same as 'up'
+ * because there is only one candidate predictor for the first row).
+ */
+ while (row < rp_end)
+ {
+ int a = *row + *prev_row++;
+ *row++ = (png_byte)a;
+ }
+
+ /* Remainder */
+ rp_end += row_info->rowbytes - bpp;
+
+ while (row < rp_end)
+ {
+ int a, b, c, pa, pb, pc, p;
+
+ c = *(prev_row - bpp);
+ a = *(row - bpp);
+ b = *prev_row++;
+
+ p = b - c;
+ pc = a - c;
+
+# ifdef PNG_USE_ABS
+ pa = abs(p);
+ pb = abs(pc);
+ pc = abs(p + pc);
+# else
+ pa = p < 0 ? -p : p;
+ pb = pc < 0 ? -pc : pc;
+ pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+# endif
+
+ if (pb < pa) pa = pb, a = b;
+ if (pc < pa) a = c;
+
+ c = b;
+ a += *row;
+ *row++ = (png_byte)a;
+ }
+}
+
+static void
+png_init_filter_functions(png_structrp pp)
+ /* This function is called once for every PNG image to set the
+ * implementations required to reverse the filtering of PNG rows. Reversing
+ * the filter is the first transformation performed on the row data. It is
+ * performed in place, therefore an implementation can be selected based on
+ * the image pixel format. If the implementation depends on image width then
+ * take care to ensure that it works correctly if the image is interlaced -
+ * interlacing causes the actual row width to vary.
+ */
+{
+ unsigned int bpp = (pp->pixel_depth + 7) >> 3;
+
+ pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub;
+ pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up;
+ pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg;
+ if (bpp == 1)
+ pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+ png_read_filter_row_paeth_1byte_pixel;
+ else
+ pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+ png_read_filter_row_paeth_multibyte_pixel;
+
+#ifdef PNG_FILTER_OPTIMIZATIONS
+ /* To use this define PNG_FILTER_OPTIMIZATIONS as the name of a function to
+ * call to install hardware optimizations for the above functions; simply
+ * replace whatever elements of the pp->read_filter[] array with a hardware
+ * specific (or, for that matter, generic) optimization.
+ *
+ * To see an example of this examine what configure.ac does when
+ * --enable-arm-neon is specified on the command line.
+ */
+ PNG_FILTER_OPTIMIZATIONS(pp, bpp);
+#endif
+}
+
void /* PRIVATE */
-png_read_filter_row(png_row_infop row_info, png_bytep row,
+png_read_filter_row(png_structrp pp, png_row_infop row_info, png_bytep row,
png_const_bytep prev_row, int filter)
{
- switch (filter)
+ /* OPTIMIZATION: DO NOT MODIFY THIS FUNCTION, instead #define
+ * PNG_FILTER_OPTIMIZATIONS to a function that overrides the generic
+ * implementations. See png_init_filter_functions above.
+ */
+ if (pp->read_filter[0] == NULL)
+ png_init_filter_functions(pp);
+ if (filter > PNG_FILTER_VALUE_NONE && filter < PNG_FILTER_VALUE_LAST)
+ pp->read_filter[filter-1](row_info, row, prev_row);
+}
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+void /* PRIVATE */
+png_read_IDAT_data(png_structrp png_ptr, png_bytep output,
+ png_alloc_size_t avail_out)
+{
+ /* Loop reading IDATs and decompressing the result into output[avail_out] */
+ png_ptr->zstream.next_out = output;
+ png_ptr->zstream.avail_out = 0; /* safety: set below */
+
+ if (output == NULL)
+ avail_out = 0;
+
+ do
{
- case PNG_FILTER_VALUE_NONE:
- break;
+ int ret;
+ png_byte tmpbuf[PNG_INFLATE_BUF_SIZE];
- case PNG_FILTER_VALUE_SUB:
+ if (png_ptr->zstream.avail_in == 0)
{
- png_size_t i;
- png_size_t istop = row_info->rowbytes;
- unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
- png_bytep rp = row + bpp;
- png_bytep lp = row;
+ uInt avail_in;
+ png_bytep buffer;
- for (i = bpp; i < istop; i++)
+ while (png_ptr->idat_size == 0)
{
- *rp = (png_byte)(((int)(*rp) + (int)(*lp++)) & 0xff);
- rp++;
+ png_crc_finish(png_ptr, 0);
+
+ png_ptr->idat_size = png_read_chunk_header(png_ptr);
+ /* This is an error even in the 'check' case because the code just
+ * consumed a non-IDAT header.
+ */
+ if (png_ptr->chunk_name != png_IDAT)
+ png_error(png_ptr, "Not enough image data");
}
- break;
+
+ avail_in = png_ptr->IDAT_read_size;
+
+ if (avail_in > png_ptr->idat_size)
+ avail_in = (uInt)png_ptr->idat_size;
+
+ /* A PNG with a gradually increasing IDAT size will defeat this attempt
+ * to minimize memory usage by causing lots of re-allocs, but
+ * realistically doing IDAT_read_size re-allocs is not likely to be a
+ * big problem.
+ */
+ buffer = png_read_buffer(png_ptr, avail_in, 0/*error*/);
+
+ png_crc_read(png_ptr, buffer, avail_in);
+ png_ptr->idat_size -= avail_in;
+
+ png_ptr->zstream.next_in = buffer;
+ png_ptr->zstream.avail_in = avail_in;
}
- case PNG_FILTER_VALUE_UP:
+
+ /* And set up the output side. */
+ if (output != NULL) /* standard read */
{
- png_size_t i;
- png_size_t istop = row_info->rowbytes;
- png_bytep rp = row;
- png_const_bytep pp = prev_row;
+ uInt out = ZLIB_IO_MAX;
- for (i = 0; i < istop; i++)
- {
- *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
- rp++;
- }
- break;
+ if (out > avail_out)
+ out = (uInt)avail_out;
+
+ avail_out -= out;
+ png_ptr->zstream.avail_out = out;
}
- case PNG_FILTER_VALUE_AVG:
+
+ else /* after last row, checking for end */
{
- png_size_t i;
- png_bytep rp = row;
- png_const_bytep pp = prev_row;
- png_bytep lp = row;
- unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
- png_size_t istop = row_info->rowbytes - bpp;
-
- for (i = 0; i < bpp; i++)
- {
- *rp = (png_byte)(((int)(*rp) +
- ((int)(*pp++) / 2 )) & 0xff);
+ png_ptr->zstream.next_out = tmpbuf;
+ png_ptr->zstream.avail_out = (sizeof tmpbuf);
+ }
- rp++;
- }
+ /* Use NO_FLUSH; this gives zlib the maximum opportunity to optimize the
+ * process. If the LZ stream is truncated the sequential reader will
+ * terminally damage the stream, above, by reading the chunk header of the
+ * following chunk (it then exits with png_error).
+ *
+ * TODO: deal more elegantly with truncated IDAT lists.
+ */
+ ret = inflate(&png_ptr->zstream, Z_NO_FLUSH);
- for (i = 0; i < istop; i++)
- {
- *rp = (png_byte)(((int)(*rp) +
- (int)(*pp++ + *lp++) / 2 ) & 0xff);
+ /* Take the unconsumed output back. */
+ if (output != NULL)
+ avail_out += png_ptr->zstream.avail_out;
- rp++;
- }
+ else /* avail_out counts the extra bytes */
+ avail_out += (sizeof tmpbuf) - png_ptr->zstream.avail_out;
+
+ png_ptr->zstream.avail_out = 0;
+
+ if (ret == Z_STREAM_END)
+ {
+ /* Do this for safety; we won't read any more into this row. */
+ png_ptr->zstream.next_out = NULL;
+
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
+
+ if (png_ptr->zstream.avail_in > 0 || png_ptr->idat_size > 0)
+ png_chunk_benign_error(png_ptr, "Extra compressed data");
break;
}
- case PNG_FILTER_VALUE_PAETH:
+
+ if (ret != Z_OK)
{
- png_size_t i;
- png_bytep rp = row;
- png_const_bytep pp = prev_row;
- png_bytep lp = row;
- png_const_bytep cp = prev_row;
- unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
- png_size_t istop=row_info->rowbytes - bpp;
-
- for (i = 0; i < bpp; i++)
- {
- *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
- rp++;
- }
+ png_zstream_error(png_ptr, ret);
- for (i = 0; i < istop; i++) /* Use leftover rp,pp */
- {
- int a, b, c, pa, pb, pc, p;
+ if (output != NULL)
+ png_chunk_error(png_ptr, png_ptr->zstream.msg);
- a = *lp++;
- b = *pp++;
- c = *cp++;
+ else /* checking */
+ {
+ png_chunk_benign_error(png_ptr, png_ptr->zstream.msg);
+ return;
+ }
+ }
+ } while (avail_out > 0);
- p = b - c;
- pc = a - c;
+ if (avail_out > 0)
+ {
+ /* The stream ended before the image; this is the same as too few IDATs so
+ * should be handled the same way.
+ */
+ if (output != NULL)
+ png_error(png_ptr, "Not enough image data");
-#ifdef PNG_USE_ABS
- pa = abs(p);
- pb = abs(pc);
- pc = abs(p + pc);
-#else
- pa = p < 0 ? -p : p;
- pb = pc < 0 ? -pc : pc;
- pc = (p + pc) < 0 ? -(p + pc) : p + pc;
-#endif
+ else /* the deflate stream contained extra data */
+ png_chunk_benign_error(png_ptr, "Too much image data");
+ }
+}
- /*
- if (pa <= pb && pa <= pc)
- p = a;
+void /* PRIVATE */
+png_read_finish_IDAT(png_structrp png_ptr)
+{
+ /* We don't need any more data and the stream should have ended, however the
+ * LZ end code may actually not have been processed. In this case we must
+ * read it otherwise stray unread IDAT data or, more likely, an IDAT chunk
+ * may still remain to be consumed.
+ */
+ if (!(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED))
+ {
+ /* The NULL causes png_read_IDAT_data to swallow any remaining bytes in
+ * the compressed stream, but the stream may be damaged too, so even after
+ * this call we may need to terminate the zstream ownership.
+ */
+ png_read_IDAT_data(png_ptr, NULL, 0);
+ png_ptr->zstream.next_out = NULL; /* safety */
- else if (pb <= pc)
- p = b;
+ /* Now clear everything out for safety; the following may not have been
+ * done.
+ */
+ if (!(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED))
+ {
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
+ }
+ }
- else
- p = c;
- */
+ /* If the zstream has not been released do it now *and* terminate the reading
+ * of the final IDAT chunk.
+ */
+ if (png_ptr->zowner == png_IDAT)
+ {
+ /* Always do this; the pointers otherwise point into the read buffer. */
+ png_ptr->zstream.next_in = NULL;
+ png_ptr->zstream.avail_in = 0;
- p = (pa <= pb && pa <= pc) ? a : (pb <= pc) ? b : c;
+ /* Now we no longer own the zstream. */
+ png_ptr->zowner = 0;
- *rp = (png_byte)(((int)(*rp) + p) & 0xff);
- rp++;
- }
- break;
- }
- default:
- /* NOT REACHED */
- break;
+ /* The slightly weird semantics of the sequential IDAT reading is that we
+ * are always in or at the end of an IDAT chunk, so we always need to do a
+ * crc_finish here. If idat_size is non-zero we also need to read the
+ * spurious bytes at the end of the chunk now.
+ */
+ (void)png_crc_finish(png_ptr, png_ptr->idat_size);
}
}
-#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
void /* PRIVATE */
-png_read_finish_row(png_structp png_ptr)
+png_read_finish_row(png_structrp png_ptr)
{
#ifdef PNG_READ_INTERLACING_SUPPORTED
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
/* TO DO: don't do this if prev_row isn't needed (requires
* read-ahead of the next row's filter byte.
*/
- png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+ memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
do
{
}
#endif /* PNG_READ_INTERLACING_SUPPORTED */
- if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
- {
- char extra;
- int ret;
-
- png_ptr->zstream.next_out = (Byte *)&extra;
- png_ptr->zstream.avail_out = (uInt)1;
-
- for (;;)
- {
- if (!(png_ptr->zstream.avail_in))
- {
- while (!png_ptr->idat_size)
- {
- png_crc_finish(png_ptr, 0);
- png_ptr->idat_size = png_read_chunk_header(png_ptr);
- if (png_ptr->chunk_name != png_IDAT)
- png_error(png_ptr, "Not enough image data");
- }
-
- png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
- png_ptr->zstream.next_in = png_ptr->zbuf;
-
- if (png_ptr->zbuf_size > png_ptr->idat_size)
- png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
-
- png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zstream.avail_in);
- png_ptr->idat_size -= png_ptr->zstream.avail_in;
- }
-
- ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
-
- if (ret == Z_STREAM_END)
- {
- if (!(png_ptr->zstream.avail_out) || png_ptr->zstream.avail_in ||
- png_ptr->idat_size)
- png_warning(png_ptr, "Extra compressed data");
-
- png_ptr->mode |= PNG_AFTER_IDAT;
- png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
- break;
- }
-
- if (ret != Z_OK)
- png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
- "Decompression Error");
-
- if (!(png_ptr->zstream.avail_out))
- {
- png_warning(png_ptr, "Extra compressed data");
- png_ptr->mode |= PNG_AFTER_IDAT;
- png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
- break;
- }
-
- }
- png_ptr->zstream.avail_out = 0;
- }
-
- if (png_ptr->idat_size || png_ptr->zstream.avail_in)
- png_warning(png_ptr, "Extra compression data");
-
- inflateReset(&png_ptr->zstream);
-
- png_ptr->mode |= PNG_AFTER_IDAT;
+ /* Here after at the end of the last row of the last pass. */
+ png_read_finish_IDAT(png_ptr);
}
#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
void /* PRIVATE */
-png_read_start_row(png_structp png_ptr)
+png_read_start_row(png_structrp png_ptr)
{
#ifdef PNG_READ_INTERLACING_SUPPORTED
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
png_size_t row_bytes;
png_debug(1, "in png_read_start_row");
- png_ptr->zstream.avail_in = 0;
+
#ifdef PNG_READ_TRANSFORMS_SUPPORTED
png_init_read_transformations(png_ptr);
#endif
max_pixel_depth = png_ptr->pixel_depth;
+ /* WARNING: * png_read_transform_info (pngrtran.c) performs a simpliar set of
+ * calculations to calculate the final pixel depth, then
+ * png_do_read_transforms actually does the transforms. This means that the
+ * code which effectively calculates this value is actually repeated in three
+ * separate places. They must all match. Innocent changes to the order of
+ * transformations can and will break libpng in a way that causes memory
+ * overwrites.
+ *
+ * TODO: fix this.
+ */
#ifdef PNG_READ_PACK_SUPPORTED
if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8)
max_pixel_depth = 8;
#ifdef PNG_READ_FILLER_SUPPORTED
if (png_ptr->transformations & (PNG_FILLER))
{
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- max_pixel_depth = 32;
-
- else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+ if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
{
if (max_pixel_depth <= 8)
max_pixel_depth = 16;
max_pixel_depth = 32;
}
- else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB ||
+ png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
{
if (max_pixel_depth <= 32)
max_pixel_depth = 32;
if (png_ptr->rowbytes > (PNG_SIZE_MAX - 1))
png_error(png_ptr, "Row has too many bytes to allocate in memory");
- png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+ memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
png_debug1(3, "width = %u,", png_ptr->width);
png_debug1(3, "height = %u,", png_ptr->height);
png_debug1(3, "irowbytes = %lu",
(unsigned long)PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1);
+ /* The sequential reader needs a buffer for IDAT, but the progressive reader
+ * does not, so free the read buffer now regardless; the sequential reader
+ * reallocates it on demand.
+ */
+ if (png_ptr->read_buffer)
+ {
+ png_bytep buffer = png_ptr->read_buffer;
+
+ png_ptr->read_buffer_size = 0;
+ png_ptr->read_buffer = NULL;
+ png_free(png_ptr, buffer);
+ }
+
+ /* Finally claim the zstream for the inflate of the IDAT data, use the bits
+ * value from the stream (note that this will result in a fatal error if the
+ * IDAT stream has a bogus deflate header window_bits value, but this should
+ * not be happening any longer!)
+ */
+ if (png_inflate_claim(png_ptr, png_IDAT, 0) != Z_OK)
+ png_error(png_ptr, png_ptr->zstream.msg);
+
png_ptr->flags |= PNG_FLAG_ROW_INIT;
}
#endif /* PNG_READ_SUPPORTED */
projects / wxWidgets.git / blobdiff