/* pngrutil.c - utilities to read a PNG file
*
- * libpng 1.0.1
- * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
- * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * March 15, 1998
+ * 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.)
*
- * This file contains routines which are only called from within
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file contains routines that are only called from within
* libpng itself during the course of reading an image.
*/
-#define PNG_INTERNAL
-#include "png.h"
+#include "pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+
+#define png_strtod(p,a,b) strtod(a,b)
+
+png_uint_32 PNGAPI
+png_get_uint_31(png_const_structrp png_ptr, png_const_bytep buf)
+{
+ png_uint_32 uval = png_get_uint_32(buf);
+
+ if (uval > PNG_UINT_31_MAX)
+ png_error(png_ptr, "PNG unsigned integer out of range");
+
+ return (uval);
+}
+
+#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_READ_cHRM_SUPPORTED)
+/* The following is a variation on the above for use with the fixed
+ * point values used for gAMA and cHRM. Instead of png_error it
+ * issues a warning and returns (-1) - an invalid value because both
+ * gAMA and cHRM use *unsigned* integers for fixed point values.
+ */
+#define PNG_FIXED_ERROR (-1)
+
+static png_fixed_point /* PRIVATE */
+png_get_fixed_point(png_structrp png_ptr, png_const_bytep buf)
+{
+ png_uint_32 uval = png_get_uint_32(buf);
+
+ if (uval <= PNG_UINT_31_MAX)
+ return (png_fixed_point)uval; /* known to be in range */
+
+ /* The caller can turn off the warning by passing NULL. */
+ if (png_ptr != NULL)
+ png_warning(png_ptr, "PNG fixed point integer out of range");
+
+ return PNG_FIXED_ERROR;
+}
+#endif
+
+#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
+/* NOTE: the read macros will obscure these definitions, so that if
+ * PNG_USE_READ_MACROS is set the library will not use them internally,
+ * but the APIs will still be available externally.
+ *
+ * The parentheses around "PNGAPI function_name" in the following three
+ * functions are necessary because they allow the macros to co-exist with
+ * these (unused but exported) functions.
+ */
+
+/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */
+png_uint_32 (PNGAPI
+png_get_uint_32)(png_const_bytep buf)
+{
+ png_uint_32 uval =
+ ((png_uint_32)(*(buf )) << 24) +
+ ((png_uint_32)(*(buf + 1)) << 16) +
+ ((png_uint_32)(*(buf + 2)) << 8) +
+ ((png_uint_32)(*(buf + 3)) ) ;
+
+ return uval;
+}
-#ifndef PNG_READ_BIG_ENDIAN_SUPPORTED
-/* Grab an unsigned 32-bit integer from a buffer in big endian format. */
-png_uint_32
-png_get_uint_32(png_bytep buf)
+/* Grab a signed 32-bit integer from a buffer in big-endian format. The
+ * data is stored in the PNG file in two's complement format and there
+ * is no guarantee that a 'png_int_32' is exactly 32 bits, therefore
+ * the following code does a two's complement to native conversion.
+ */
+png_int_32 (PNGAPI
+png_get_int_32)(png_const_bytep buf)
{
- png_uint_32 i;
+ png_uint_32 uval = png_get_uint_32(buf);
+ if ((uval & 0x80000000) == 0) /* non-negative */
+ return uval;
+
+ uval = (uval ^ 0xffffffff) + 1; /* 2's complement: -x = ~x+1 */
+ return -(png_int_32)uval;
+}
- i = ((png_uint_32)(*buf) << 24) +
- ((png_uint_32)(*(buf + 1)) << 16) +
- ((png_uint_32)(*(buf + 2)) << 8) +
- (png_uint_32)(*(buf + 3));
+/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */
+png_uint_16 (PNGAPI
+png_get_uint_16)(png_const_bytep buf)
+{
+ /* ANSI-C requires an int value to accomodate at least 16 bits so this
+ * works and allows the compiler not to worry about possible narrowing
+ * on 32 bit systems. (Pre-ANSI systems did not make integers smaller
+ * than 16 bits either.)
+ */
+ unsigned int val =
+ ((unsigned int)(*buf) << 8) +
+ ((unsigned int)(*(buf + 1)));
- return (i);
+ return (png_uint_16)val;
}
-#if defined(PNG_READ_pCAL_SUPPORTED)
-/* Grab a signed 32-bit integer from a buffer in big endian format. The
- * data is stored in the PNG file in two's complement format, and it is
- * assumed that the machine format for signed integers is the same. */
-png_int_32
-png_get_int_32(png_bytep buf)
+#endif /* PNG_READ_INT_FUNCTIONS_SUPPORTED */
+
+/* Read and check the PNG file signature */
+void /* PRIVATE */
+png_read_sig(png_structrp png_ptr, png_inforp info_ptr)
{
- png_int_32 i;
+ png_size_t num_checked, num_to_check;
+
+ /* Exit if the user application does not expect a signature. */
+ if (png_ptr->sig_bytes >= 8)
+ return;
- i = ((png_int_32)(*buf) << 24) +
- ((png_int_32)(*(buf + 1)) << 16) +
- ((png_int_32)(*(buf + 2)) << 8) +
- (png_int_32)(*(buf + 3));
+ num_checked = png_ptr->sig_bytes;
+ num_to_check = 8 - num_checked;
- return (i);
+#ifdef PNG_IO_STATE_SUPPORTED
+ png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE;
+#endif
+
+ /* The signature must be serialized in a single I/O call. */
+ png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
+ png_ptr->sig_bytes = 8;
+
+ if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
+ {
+ if (num_checked < 4 &&
+ png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
+ png_error(png_ptr, "Not a PNG file");
+ else
+ png_error(png_ptr, "PNG file corrupted by ASCII conversion");
+ }
+ if (num_checked < 3)
+ png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
}
-#endif /* PNG_READ_pCAL_SUPPORTED */
-/* Grab an unsigned 16-bit integer from a buffer in big endian format. */
-png_uint_16
-png_get_uint_16(png_bytep buf)
+/* Read the chunk header (length + type name).
+ * Put the type name into png_ptr->chunk_name, and return the length.
+ */
+png_uint_32 /* PRIVATE */
+png_read_chunk_header(png_structrp png_ptr)
{
- png_uint_16 i;
+ png_byte buf[8];
+ png_uint_32 length;
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_HDR;
+#endif
+
+ /* Read the length and the chunk name.
+ * This must be performed in a single I/O call.
+ */
+ png_read_data(png_ptr, buf, 8);
+ length = png_get_uint_31(png_ptr, buf);
+
+ /* Put the chunk name into png_ptr->chunk_name. */
+ png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(buf+4);
+
+ png_debug2(0, "Reading %lx chunk, length = %lu",
+ (unsigned long)png_ptr->chunk_name, (unsigned long)length);
+
+ /* Reset the crc and run it over the chunk name. */
+ png_reset_crc(png_ptr);
+ png_calculate_crc(png_ptr, buf + 4, 4);
+
+ /* Check to see if chunk name is valid. */
+ png_check_chunk_name(png_ptr, png_ptr->chunk_name);
- i = (png_uint_16)(((png_uint_16)(*buf) << 8) +
- (png_uint_16)(*(buf + 1)));
+#ifdef PNG_IO_STATE_SUPPORTED
+ png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_DATA;
+#endif
- return (i);
+ return length;
}
-#endif /* PNG_READ_BIG_ENDIAN_SUPPORTED */
/* Read data, and (optionally) run it through the CRC. */
-void
-png_crc_read(png_structp png_ptr, png_bytep buf, png_size_t length)
+void /* PRIVATE */
+png_crc_read(png_structrp png_ptr, png_bytep buf, png_uint_32 length)
{
+ if (png_ptr == NULL)
+ return;
+
png_read_data(png_ptr, buf, length);
png_calculate_crc(png_ptr, buf, length);
}
/* 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
- 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
-png_crc_finish(png_structp png_ptr, png_uint_32 skip)
+ * 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_structrp png_ptr, png_uint_32 skip)
{
- png_uint_32 i;
-
- for (i = skip; i > (png_uint_32)png_ptr->zbuf_size; i -= png_ptr->zbuf_size)
- {
- png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
- }
- if (i)
+ /* 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_size_t)i);
+ png_uint_32 len;
+ png_byte tmpbuf[PNG_INFLATE_BUF_SIZE];
+
+ 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_ptr->chunk_name[0] & 0x20 && /* Ancillary */
- !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) ||
- (!(png_ptr->chunk_name[0] & 0x20) && /* Critical */
- png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE))
+ if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) ?
+ !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) :
+ (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE))
{
png_chunk_warning(png_ptr, "CRC error");
}
+
else
{
- png_chunk_error(png_ptr, "CRC error");
+ png_chunk_benign_error(png_ptr, "CRC error");
+ return (0);
}
+
return (1);
}
}
/* Compare the CRC stored in the PNG file with that calculated by libpng from
- the data it has read thus far. */
-int
-png_crc_error(png_structp png_ptr)
+ * the data it has read thus far.
+ */
+int /* PRIVATE */
+png_crc_error(png_structrp png_ptr)
{
png_byte crc_bytes[4];
png_uint_32 crc;
int need_crc = 1;
- if (png_ptr->chunk_name[0] & 0x20) /* ancillary */
+ 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))
need_crc = 0;
}
- else /* critical */
+
+ else /* critical */
{
if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
need_crc = 0;
}
+#ifdef PNG_IO_STATE_SUPPORTED
+ png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_CRC;
+#endif
+
+ /* The chunk CRC must be serialized in a single I/O call. */
png_read_data(png_ptr, crc_bytes, 4);
if (need_crc)
crc = png_get_uint_32(crc_bytes);
return ((int)(crc != png_ptr->crc));
}
+
else
return (0);
}
+/* 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_bytep buffer = png_ptr->read_buffer;
+
+ if (buffer != NULL && new_size > png_ptr->read_buffer_size)
+ {
+ png_ptr->read_buffer = NULL;
+ png_ptr->read_buffer = NULL;
+ png_ptr->read_buffer_size = 0;
+ png_free(png_ptr, buffer);
+ buffer = NULL;
+ }
+
+ if (buffer == NULL)
+ {
+ buffer = png_voidcast(png_bytep, png_malloc_base(png_ptr, new_size));
+
+ if (buffer != NULL)
+ {
+ 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
+ {
+#ifdef PNG_ERROR_TEXT_SUPPORTED
+ png_chunk_error(png_ptr, "insufficient memory to read chunk");
+#endif
+ }
+ }
+ }
+
+ 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.
+ */
+ (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
+ }
+
+ /* 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 */
+
+ /* Set this for safety, just in case the previous owner left pointers to
+ * memory allocations.
+ */
+ 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 (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
+ }
+
+ else
+ {
+# if ZLIB_VERNUM < 0x1240
+ ret = inflateInit(&png_ptr->zstream);
+# else
+ ret = inflateInit2(&png_ptr->zstream, window_bits);
+# endif
+
+ if (ret == Z_OK)
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED;
+ }
+
+ if (ret == Z_OK)
+ png_ptr->zowner = owner;
+
+ 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;
+ png_ptr->zstream.avail_out = 0;
+
+ /* Read directly into the output if it is available (this is set to
+ * a local buffer below if output is NULL).
+ */
+ if (output != NULL)
+ png_ptr->zstream.next_out = output;
+
+ do
+ {
+ 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 */
+
+ avail = ZLIB_IO_MAX;
+
+ if (avail_in < avail)
+ avail = (uInt)avail_in; /* safe: < than ZLIB_IO_MAX */
+
+ avail_in -= avail;
+ png_ptr->zstream.avail_in = avail;
+
+ /* 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);
+ }
+
+ if (avail_out < avail)
+ avail = (uInt)avail_out; /* safe: < ZLIB_IO_MAX */
+
+ 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.
+ */
+ 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 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).
+ */
+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*/)
+{
+ /* 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
+
+ if (limit >= prefix_size + (terminate != 0))
+ {
+ int ret;
+
+ limit -= prefix_size + (terminate != 0);
+
+ if (limit < *newlength)
+ *newlength = limit;
+
+ /* 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.
+ */
+ ret = png_inflate_claim(png_ptr, png_ptr->chunk_name,
+ png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN ? 15 : 0);
+
+ if (ret == Z_OK)
+ {
+ 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 (ret == Z_STREAM_END)
+ {
+ /* 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)
+ {
+ /* 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);
+ }
+ }
+
+ else
+ {
+ /* inflateReset failed, store the error message */
+ png_zstream_error(png_ptr, ret);
+
+ if (ret == Z_STREAM_END)
+ ret = PNG_UNEXPECTED_ZLIB_RETURN;
+ }
+ }
+
+ 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
+ {
+ /* Application/configuration limits exceeded */
+ png_zstream_error(png_ptr, Z_MEM_ERROR);
+ return Z_MEM_ERROR;
+ }
+}
+#endif /* PNG_READ_COMPRESSED_TEXT_SUPPORTED */
+
+#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)
+ {
+ 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 */
+
+ do
+ {
+ if (png_ptr->zstream.avail_in == 0)
+ {
+ if (read_size > *chunk_bytes)
+ read_size = (uInt)*chunk_bytes;
+ *chunk_bytes -= read_size;
+
+ if (read_size > 0)
+ png_crc_read(png_ptr, read_buffer, read_size);
+
+ 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));
+ }
+ 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;
+ }
+
+ else
+ {
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed");
+ return Z_STREAM_ERROR;
+ }
+}
+#endif
-/* read and check the IDHR chunk */
-void
-png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+/* Read and check the IDHR chunk */
+void /* PRIVATE */
+png_handle_IHDR(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
png_byte buf[13];
png_uint_32 width, height;
int bit_depth, color_type, compression_type, filter_type;
int interlace_type;
- png_debug(1, "in png_handle_IHDR\n");
+ png_debug(1, "in png_handle_IHDR");
- if (png_ptr->mode != PNG_BEFORE_IHDR)
- png_error(png_ptr, "Out of place IHDR");
+ if (png_ptr->mode & PNG_HAVE_IHDR)
+ png_chunk_error(png_ptr, "out of place");
- /* check the length */
+ /* 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;
png_crc_read(png_ptr, buf, 13);
png_crc_finish(png_ptr, 0);
- width = png_get_uint_32(buf);
- height = png_get_uint_32(buf + 4);
+ width = png_get_uint_31(png_ptr, buf);
+ height = png_get_uint_31(png_ptr, buf + 4);
bit_depth = buf[8];
color_type = buf[9];
compression_type = buf[10];
filter_type = buf[11];
interlace_type = buf[12];
- /* check for width and height valid values */
- if (width == 0 || width > (png_uint_32)2147483647L || height == 0 ||
- height > (png_uint_32)2147483647L)
- png_error(png_ptr, "Invalid image size in IHDR");
-
- /* check other values */
- if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 &&
- bit_depth != 8 && bit_depth != 16)
- png_error(png_ptr, "Invalid bit depth in IHDR");
-
- if (color_type < 0 || color_type == 1 ||
- color_type == 5 || color_type > 6)
- png_error(png_ptr, "Invalid color type in IHDR");
-
- if ((color_type == PNG_COLOR_TYPE_PALETTE && bit_depth) > 8 ||
- ((color_type == PNG_COLOR_TYPE_RGB ||
- color_type == PNG_COLOR_TYPE_GRAY_ALPHA ||
- color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8))
- png_error(png_ptr, "Invalid color type/bit depth combination in IHDR");
-
- if (interlace_type >= PNG_INTERLACE_LAST)
- png_error(png_ptr, "Unknown interlace method in IHDR");
-
- if (compression_type != PNG_COMPRESSION_TYPE_BASE)
- png_error(png_ptr, "Unknown compression method in IHDR");
-
- if (filter_type != PNG_FILTER_TYPE_BASE)
- png_error(png_ptr, "Unknown filter method in IHDR");
-
- /* set internal variables */
+ /* Set internal variables */
png_ptr->width = width;
png_ptr->height = height;
png_ptr->bit_depth = (png_byte)bit_depth;
png_ptr->interlaced = (png_byte)interlace_type;
png_ptr->color_type = (png_byte)color_type;
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ png_ptr->filter_type = (png_byte)filter_type;
+#endif
+ png_ptr->compression_type = (png_byte)compression_type;
- /* find number of channels */
+ /* Find number of channels */
switch (png_ptr->color_type)
{
+ default: /* invalid, png_set_IHDR calls png_error */
case PNG_COLOR_TYPE_GRAY:
case PNG_COLOR_TYPE_PALETTE:
png_ptr->channels = 1;
break;
+
case PNG_COLOR_TYPE_RGB:
png_ptr->channels = 3;
break;
+
case PNG_COLOR_TYPE_GRAY_ALPHA:
png_ptr->channels = 2;
break;
+
case PNG_COLOR_TYPE_RGB_ALPHA:
png_ptr->channels = 4;
break;
}
- /* set up other useful info */
+ /* Set up other useful info */
png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth *
png_ptr->channels);
- png_ptr->rowbytes = ((png_ptr->width *
- (png_uint_32)png_ptr->pixel_depth + 7) >> 3);
- png_debug1(3,"bit_depth = %d\n", png_ptr->bit_depth);
- png_debug1(3,"channels = %d\n", png_ptr->channels);
- png_debug1(3,"rowbytes = %d\n", png_ptr->rowbytes);
+ png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->width);
+ png_debug1(3, "bit_depth = %d", png_ptr->bit_depth);
+ png_debug1(3, "channels = %d", png_ptr->channels);
+ png_debug1(3, "rowbytes = %lu", (unsigned long)png_ptr->rowbytes);
png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth,
- color_type, interlace_type, compression_type, filter_type);
+ color_type, interlace_type, compression_type, filter_type);
}
-/* read and check the palette */
-void
-png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+/* Read and check the palette */
+void /* PRIVATE */
+png_handle_PLTE(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
- png_colorp palette;
+ png_color palette[PNG_MAX_PALETTE_LENGTH];
int num, i;
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+ png_colorp pal_ptr;
+#endif
- png_debug(1, "in png_handle_PLTE\n");
+ 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 defined (PNG_READ_tRNS_SUPPORTED)
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR))
{
- if (info_ptr != NULL && info_ptr->valid & PNG_INFO_tRNS)
- {
- if (png_ptr->num_trans > png_ptr->num_palette)
- {
- png_warning(png_ptr, "Truncating incorrect tRNS chunk length");
- png_ptr->num_trans = png_ptr->num_palette;
- }
- }
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "ignored in grayscale PNG");
+ return;
}
-#endif
-#if !defined(PNG_READ_OPT_PLTE_SUPPORTED)
+#ifndef PNG_READ_OPT_PLTE_SUPPORTED
if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
{
png_crc_finish(png_ptr, length);
}
#endif
- if (length % 3)
+ 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;
- palette = (png_colorp)png_zalloc(png_ptr, (uInt)num, sizeof (png_color));
- png_ptr->flags |= PNG_FLAG_FREE_PALETTE;
+
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+ for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++)
+ {
+ png_byte buf[3];
+
+ png_crc_read(png_ptr, buf, 3);
+ pal_ptr->red = buf[0];
+ pal_ptr->green = buf[1];
+ pal_ptr->blue = buf[2];
+ }
+#else
for (i = 0; i < num; i++)
{
png_byte buf[3];
png_crc_read(png_ptr, buf, 3);
- /* don't depend upon png_color being any order */
+ /* Don't depend upon png_color being any order */
palette[i].red = buf[0];
palette[i].green = buf[1];
palette[i].blue = buf[2];
}
+#endif
- /* If we actually NEED the PLTE chunk (ie for a paletted image), we do
- whatever the normal CRC configuration tells us. However, if we
- have an RGB image, the PLTE can be considered ancillary, so
- we will act as though it is. */
-#if !defined(PNG_READ_OPT_PLTE_SUPPORTED)
+ /* If we actually need the PLTE chunk (ie for a paletted image), we do
+ * whatever the normal CRC configuration tells us. However, if we
+ * have an RGB image, the PLTE can be considered ancillary, so
+ * we will act as though it is.
+ */
+#ifndef PNG_READ_OPT_PLTE_SUPPORTED
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
#endif
{
png_crc_finish(png_ptr, 0);
}
-#if !defined(PNG_READ_OPT_PLTE_SUPPORTED)
+
+#ifndef PNG_READ_OPT_PLTE_SUPPORTED
else if (png_crc_error(png_ptr)) /* Only if we have a CRC error */
{
/* If we don't want to use the data from an ancillary chunk,
- 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). */
+ * 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))
{
if (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)
{
- png_chunk_error(png_ptr, "CRC error");
+ png_chunk_benign_error(png_ptr, "CRC error");
}
+
else
{
png_chunk_warning(png_ptr, "CRC error");
- png_ptr->flags &= ~PNG_FLAG_FREE_PALETTE;
- png_zfree(png_ptr, palette);
return;
}
}
+
/* Otherwise, we (optionally) emit a warning and use the chunk. */
else if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN))
{
}
}
#endif
- png_ptr->palette = palette;
- png_ptr->num_palette = (png_uint_16)num;
+
+ /* 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->num_trans > 0 ||
+ (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS) != 0))
+ {
+ /* 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 != 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
-png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+void /* PRIVATE */
+png_handle_IEND(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
- png_debug(1, "in png_handle_IEND\n");
+ 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");
- /* to quiet compiler warnings about unused info_ptr */
- if (info_ptr == NULL)
- return;
- }
+ png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND);
- png_ptr->mode |= PNG_AFTER_IDAT | PNG_HAVE_IEND;
+ png_crc_finish(png_ptr, length);
if (length != 0)
- {
- png_warning(png_ptr, "Incorrect IEND chunk length");
- }
- png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
+
+ PNG_UNUSED(info_ptr)
}
-#if defined(PNG_READ_gAMA_SUPPORTED)
-void
-png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+#ifdef PNG_READ_gAMA_SUPPORTED
+void /* PRIVATE */
+png_handle_gAMA(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
- png_uint_32 igamma;
- float file_gamma;
+ png_fixed_point igamma;
png_byte buf[4];
- png_debug(1, "in png_handle_gAMA\n");
+ png_debug(1, "in png_handle_gAMA");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before gAMA");
- else if (png_ptr->mode & PNG_HAVE_IDAT)
- {
- 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");
+ png_chunk_error(png_ptr, "missing IHDR");
- else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_gAMA
-#if defined(PNG_READ_sRGB_SUPPORTED)
- && !(info_ptr->valid & PNG_INFO_sRGB)
-#endif
- )
+ else if (png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE))
{
- 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;
}
png_crc_read(png_ptr, buf, 4);
- if (png_crc_finish(png_ptr, 0))
- return;
- igamma = png_get_uint_32(buf);
- /* check for zero gamma */
- if (igamma == 0)
+ if (png_crc_finish(png_ptr, 0))
return;
-#if defined(PNG_READ_sRGB_SUPPORTED)
- if (info_ptr->valid & PNG_INFO_sRGB)
- if(igamma != (png_uint_32)45000L)
- {
- png_warning(png_ptr,
- "Ignoring incorrect gAMA value when sRGB is also present");
-#ifndef PNG_NO_STDIO
- fprintf(stderr, "igamma = %lu\n", igamma);
-#endif
- return;
- }
-#endif /* PNG_READ_sRGB_SUPPORTED */
+ igamma = png_get_fixed_point(NULL, buf);
- file_gamma = (float)igamma / (float)100000.0;
-#ifdef PNG_READ_GAMMA_SUPPORTED
- png_ptr->gamma = file_gamma;
-#endif
- png_set_gAMA(png_ptr, info_ptr, file_gamma);
+ png_colorspace_set_gamma(png_ptr, &png_ptr->colorspace, igamma);
+ png_colorspace_sync(png_ptr, info_ptr);
}
#endif
-#if defined(PNG_READ_sBIT_SUPPORTED)
-void
-png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+#ifdef PNG_READ_sBIT_SUPPORTED
+void /* PRIVATE */
+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\n");
+ 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");
- else if (png_ptr->mode & PNG_HAVE_IDAT)
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ 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");
- }
- else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_sBIT)
+
+ 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;
}
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
truelen = 3;
+
else
- truelen = (png_size_t)png_ptr->channels;
+ truelen = png_ptr->channels;
- if (length != truelen)
+ 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;
}
png_crc_read(png_ptr, buf, truelen);
+
if (png_crc_finish(png_ptr, 0))
return;
png_ptr->sig_bit.blue = buf[2];
png_ptr->sig_bit.alpha = buf[3];
}
+
else
{
png_ptr->sig_bit.gray = buf[0];
+ png_ptr->sig_bit.red = buf[0];
+ png_ptr->sig_bit.green = buf[0];
+ png_ptr->sig_bit.blue = buf[0];
png_ptr->sig_bit.alpha = buf[1];
}
+
png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit));
}
#endif
-#if defined(PNG_READ_cHRM_SUPPORTED)
-void
-png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+#ifdef PNG_READ_cHRM_SUPPORTED
+void /* PRIVATE */
+png_handle_cHRM(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
- png_byte buf[4];
- png_uint_32 val;
- float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y;
+ png_byte buf[32];
+ png_xy xy;
- png_debug(1, "in png_handle_cHRM\n");
+ png_debug(1, "in png_handle_cHRM");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before sBIT");
- else if (png_ptr->mode & PNG_HAVE_IDAT)
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ 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);
+ 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, "Missing PLTE before cHRM");
- else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_cHRM
-#if defined(PNG_READ_sRGB_SUPPORTED)
- && !(info_ptr->valid & PNG_INFO_sRGB)
-#endif
- )
+ if (length != 32)
{
- png_warning(png_ptr, "Duplicate cHRM chunk");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
return;
}
- if (length != 32)
+ png_crc_read(png_ptr, buf, 32);
+
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ 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_warning(png_ptr, "Incorrect cHRM chunk length");
- png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid values");
return;
}
- png_crc_read(png_ptr, buf, 4);
- val = png_get_uint_32(buf);
- white_x = (float)val / (float)100000.0;
-
- png_crc_read(png_ptr, buf, 4);
- val = png_get_uint_32(buf);
- white_y = (float)val / (float)100000.0;
+ /* If a colorspace error has already been output skip this chunk */
+ if (png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID)
+ return;
- if (white_x < 0 || white_x > 0.8 || white_y < 0 || white_y > 0.8 ||
- white_x + white_y > 1.0)
+ if (png_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM)
{
- png_warning(png_ptr, "Invalid cHRM white point");
- png_crc_finish(png_ptr, 24);
+ png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID;
+ png_colorspace_sync(png_ptr, info_ptr);
+ png_chunk_benign_error(png_ptr, "duplicate");
return;
}
- png_crc_read(png_ptr, buf, 4);
- val = png_get_uint_32(buf);
- red_x = (float)val / (float)100000.0;
+ 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
- png_crc_read(png_ptr, buf, 4);
- val = png_get_uint_32(buf);
- red_y = (float)val / (float)100000.0;
+#ifdef PNG_READ_sRGB_SUPPORTED
+void /* PRIVATE */
+png_handle_sRGB(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_byte intent;
+
+ png_debug(1, "in png_handle_sRGB");
- if (red_x < 0 || red_x > 0.8 || red_y < 0 || red_y > 0.8 ||
- red_x + red_y > 1.0)
+ 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, "Invalid cHRM red point");
- png_crc_finish(png_ptr, 16);
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
return;
}
- png_crc_read(png_ptr, buf, 4);
- val = png_get_uint_32(buf);
- green_x = (float)val / (float)100000.0;
+ if (length != 1)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
+ return;
+ }
- png_crc_read(png_ptr, buf, 4);
- val = png_get_uint_32(buf);
- green_y = (float)val / (float)100000.0;
+ png_crc_read(png_ptr, &intent, 1);
+
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ /* If a colorspace error has already been output skip this chunk */
+ if (png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID)
+ return;
- if (green_x < 0 || green_x > 0.8 || green_y < 0 || green_y > 0.8 ||
- green_x + green_y > 1.0)
+ /* 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)
{
- png_warning(png_ptr, "Invalid cHRM green point");
- png_crc_finish(png_ptr, 8);
+ png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID;
+ png_colorspace_sync(png_ptr, info_ptr);
+ png_chunk_benign_error(png_ptr, "too many profiles");
return;
}
- png_crc_read(png_ptr, buf, 4);
- val = png_get_uint_32(buf);
- blue_x = (float)val / (float)100000.0;
+ (void)png_colorspace_set_sRGB(png_ptr, &png_ptr->colorspace, intent);
+ png_colorspace_sync(png_ptr, info_ptr);
+}
+#endif /* PNG_READ_sRGB_SUPPORTED */
- png_crc_read(png_ptr, buf, 4);
- val = png_get_uint_32(buf);
- blue_y = (float)val / (float)100000.0;
+#ifdef PNG_READ_iCCP_SUPPORTED
+void /* PRIVATE */
+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_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_chunk_error(png_ptr, "missing IHDR");
- if (blue_x < (float)0 || blue_x > (float)0.8 || blue_y < (float)0 ||
- blue_y > (float)0.8 || blue_x + blue_y > (float)1.0)
+ else if (png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE))
{
- png_warning(png_ptr, "Invalid cHRM blue point");
- png_crc_finish(png_ptr, 0);
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
return;
}
- if (png_crc_finish(png_ptr, 0))
+ /* 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_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "too short");
+ return;
+ }
+
+ /* If a colorspace error has already been output skip this chunk */
+ if (png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID)
+ {
+ png_crc_finish(png_ptr, length);
return;
+ }
-#if defined(PNG_READ_sRGB_SUPPORTED)
- if (info_ptr->valid & PNG_INFO_sRGB)
+ /* 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)
+ {
+ 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_crc_read(png_ptr, (png_bytep)keyword, read_length);
+ length -= read_length;
+
+ keyword_length = 0;
+ while (keyword_length < 80 && keyword_length < read_length &&
+ keyword[keyword_length] != 0)
+ ++keyword_length;
+
+ /* TODO: make the keyword checking common */
+ if (keyword_length >= 1 && keyword_length <= 79)
{
- if (fabs(white_x - (float).3127) > (float).001 ||
- fabs(white_y - (float).3290) > (float).001 ||
- fabs( red_x - (float).6400) > (float).001 ||
- fabs( red_y - (float).3300) > (float).001 ||
- fabs(green_x - (float).3000) > (float).001 ||
- fabs(green_y - (float).6000) > (float).001 ||
- fabs( blue_x - (float).1500) > (float).001 ||
- fabs( blue_y - (float).0600) > (float).001)
+ /* 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;
- png_warning(png_ptr,
- "Ignoring incorrect cHRM value when sRGB is also present");
-#ifndef PNG_NO_STDIO
- fprintf(stderr,"wx=%f, wy=%f, rx=%f, ry=%f\n",
- white_x, white_y, red_x, red_y);
- fprintf(stderr,"gx=%f, gy=%f, bx=%f, by=%f\n",
- green_x, green_y, blue_x, blue_y);
-#endif
+ 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);
+
+ 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 (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;
+ }
+
+ else
+ errmsg = "out of memory";
+ }
+
+ /* else png_icc_check_header output an error */
+ }
+
+ /* else png_icc_check_length output an error */
+ }
+
+ else /* profile truncated */
+ errmsg = png_ptr->zstream.msg;
+
+ /* Release the stream */
+ png_ptr->zowner = 0;
+ }
+
+ else /* png_inflate_claim failed */
+ errmsg = png_ptr->zstream.msg;
}
- return;
+
+ else
+ errmsg = "bad compression method"; /* or missing */
}
-#endif /* PNG_READ_sRGB_SUPPORTED */
- png_set_cHRM(png_ptr, info_ptr,
- white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y);
+ else
+ errmsg = "bad keyword";
+ }
+
+ 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
+#endif /* PNG_READ_iCCP_SUPPORTED */
-#if defined(PNG_READ_sRGB_SUPPORTED)
-void
-png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+#ifdef PNG_READ_sPLT_SUPPORTED
+void /* PRIVATE */
+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 */
{
- int intent;
- png_byte buf[1];
+ 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_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)
+ {
+ png_crc_finish(png_ptr, length);
+ return;
+ }
- png_debug(1, "in png_handle_sRGB\n");
+ if (--png_ptr->user_chunk_cache_max == 1)
+ {
+ png_warning(png_ptr, "No space in chunk cache for sPLT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ }
+#endif
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Missing IHDR before sRGB");
+ png_chunk_error(png_ptr, "missing IHDR");
+
else if (png_ptr->mode & PNG_HAVE_IDAT)
{
- png_warning(png_ptr, "Invalid sRGB 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 sRGB chunk");
- else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_sRGB)
+#ifdef PNG_MAX_MALLOC_64K
+ if (length > 65535U)
{
- png_warning(png_ptr, "Duplicate sRGB chunk");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "too large to fit in memory");
return;
}
+#endif
- if (length != 1)
+ buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/);
+ if (buffer == NULL)
{
- png_warning(png_ptr, "Incorrect sRGB chunk length");
png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of memory");
return;
}
- png_crc_read(png_ptr, buf, 1);
- if (png_crc_finish(png_ptr, 0))
+
+ /* 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.
+ */
+ png_crc_read(png_ptr, buffer, length);
+
+ if (png_crc_finish(png_ptr, skip))
+ return;
+
+ buffer[length] = 0;
+
+ 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 > buffer + length - 2)
+ {
+ png_warning(png_ptr, "malformed sPLT chunk");
return;
+ }
- intent = buf[0];
- /* check for bad intent */
- if (intent >= PNG_sRGB_INTENT_LAST)
+ 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.
+ */
+ data_length = length - (png_uint_32)(entry_start - buffer);
+
+ /* Integrity-check the data length */
+ if (data_length % entry_size)
{
- png_warning(png_ptr, "Unknown sRGB intent");
+ png_warning(png_ptr, "sPLT chunk has bad length");
return;
}
-#if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
- if ((info_ptr->valid & PNG_INFO_gAMA))
- if((png_uint_32)(png_ptr->gamma*(float)100000.+.5) != (png_uint_32)45000L)
+ dl = (png_int_32)(data_length / entry_size);
+ max_dl = PNG_SIZE_MAX / (sizeof (png_sPLT_entry));
+
+ if (dl > max_dl)
+ {
+ png_warning(png_ptr, "sPLT chunk too long");
+ return;
+ }
+
+ new_palette.nentries = (png_int_32)(data_length / entry_size);
+
+ new_palette.entries = (png_sPLT_entryp)png_malloc_warn(
+ png_ptr, new_palette.nentries * (sizeof (png_sPLT_entry)));
+
+ if (new_palette.entries == NULL)
+ {
+ png_warning(png_ptr, "sPLT chunk requires too much memory");
+ return;
+ }
+
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+ for (i = 0; i < new_palette.nentries; i++)
+ {
+ pp = new_palette.entries + i;
+
+ if (new_palette.depth == 8)
{
- png_warning(png_ptr,
- "Ignoring incorrect gAMA value when sRGB is also present");
-#ifndef PNG_NO_STDIO
- fprintf(stderr,"gamma=%f\n",png_ptr->gamma);
-#endif
+ pp->red = *entry_start++;
+ pp->green = *entry_start++;
+ pp->blue = *entry_start++;
+ pp->alpha = *entry_start++;
}
-#endif /* PNG_READ_gAMA_SUPPORTED */
-#ifdef PNG_READ_cHRM_SUPPORTED
- if (info_ptr->valid & PNG_INFO_cHRM)
- if (fabs(info_ptr->x_white - (float).3127) > (float).001 ||
- fabs(info_ptr->y_white - (float).3290) > (float).001 ||
- fabs( info_ptr->x_red - (float).6400) > (float).001 ||
- fabs( info_ptr->y_red - (float).3300) > (float).001 ||
- fabs(info_ptr->x_green - (float).3000) > (float).001 ||
- fabs(info_ptr->y_green - (float).6000) > (float).001 ||
- fabs( info_ptr->x_blue - (float).1500) > (float).001 ||
- fabs( info_ptr->y_blue - (float).0600) > (float).001)
- {
- png_warning(png_ptr,
- "Ignoring incorrect cHRM value when sRGB is also present");
- }
-#endif /* PNG_READ_cHRM_SUPPORTED */
+ else
+ {
+ pp->red = png_get_uint_16(entry_start); entry_start += 2;
+ pp->green = png_get_uint_16(entry_start); entry_start += 2;
+ pp->blue = png_get_uint_16(entry_start); entry_start += 2;
+ pp->alpha = png_get_uint_16(entry_start); entry_start += 2;
+ }
- png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent);
+ pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
+ }
+#else
+ pp = new_palette.entries;
+
+ for (i = 0; i < new_palette.nentries; i++)
+ {
+
+ if (new_palette.depth == 8)
+ {
+ pp[i].red = *entry_start++;
+ pp[i].green = *entry_start++;
+ pp[i].blue = *entry_start++;
+ pp[i].alpha = *entry_start++;
+ }
+
+ else
+ {
+ pp[i].red = png_get_uint_16(entry_start); entry_start += 2;
+ pp[i].green = png_get_uint_16(entry_start); entry_start += 2;
+ pp[i].blue = png_get_uint_16(entry_start); entry_start += 2;
+ pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2;
+ }
+
+ pp[i].frequency = png_get_uint_16(entry_start); entry_start += 2;
+ }
+#endif
+
+ /* Discard all chunk data except the name and stash that */
+ new_palette.name = (png_charp)buffer;
+
+ png_set_sPLT(png_ptr, info_ptr, &new_palette, 1);
+
+ png_free(png_ptr, new_palette.entries);
}
-#endif /* PNG_READ_sRGB_SUPPORTED */
+#endif /* PNG_READ_sPLT_SUPPORTED */
-#if defined(PNG_READ_tRNS_SUPPORTED)
-void
-png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+#ifdef PNG_READ_tRNS_SUPPORTED
+void /* PRIVATE */
+png_handle_tRNS(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
- png_debug(1, "in png_handle_tRNS\n");
+ 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)
+
+ 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 (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
{
- 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");
- }
- else if (length > png_ptr->num_palette)
+ png_byte buf[2];
+
+ 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;
}
- png_ptr->trans = (png_bytep)png_malloc(png_ptr, length);
- png_ptr->flags |= PNG_FLAG_FREE_TRANS;
- png_crc_read(png_ptr, png_ptr->trans, (png_size_t)length);
- png_ptr->num_trans = (png_uint_16)length;
+ png_crc_read(png_ptr, buf, 2);
+ png_ptr->num_trans = 1;
+ png_ptr->trans_color.gray = png_get_uint_16(buf);
}
+
else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
{
png_byte buf[6];
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_values.red = png_get_uint_16(buf);
- png_ptr->trans_values.green = png_get_uint_16(buf + 2);
- png_ptr->trans_values.blue = png_get_uint_16(buf + 4);
+ png_ptr->trans_color.red = png_get_uint_16(buf);
+ png_ptr->trans_color.green = png_get_uint_16(buf + 2);
+ png_ptr->trans_color.blue = png_get_uint_16(buf + 4);
}
- else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
{
- png_byte buf[6];
+ if (!(png_ptr->mode & PNG_HAVE_PLTE))
+ {
+ /* 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 != 2)
+ if (length > png_ptr->num_palette || length > PNG_MAX_PALETTE_LENGTH ||
+ length == 0)
{
- 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, 2);
- png_ptr->num_trans = 1;
- png_ptr->trans_values.gray = png_get_uint_16(buf);
+ 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;
}
if (png_crc_finish(png_ptr, 0))
+ {
+ png_ptr->num_trans = 0;
return;
+ }
- png_set_tRNS(png_ptr, info_ptr, png_ptr->trans, png_ptr->num_trans,
- &(png_ptr->trans_values));
+ /* 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));
}
#endif
-#if defined(PNG_READ_bKGD_SUPPORTED)
-void
-png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+#ifdef PNG_READ_bKGD_SUPPORTED
+void /* PRIVATE */
+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\n");
+ 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;
- }
- else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
- !(png_ptr->mode & PNG_HAVE_PLTE))
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ 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)
+
+ 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 (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
truelen = 1;
+
else if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
truelen = 6;
+
else
truelen = 2;
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;
}
png_crc_read(png_ptr, buf, truelen);
+
if (png_crc_finish(png_ptr, 0))
return;
/* We convert the index value into RGB components so that we can allow
* arbitrary RGB values for background when we have transparency, and
* so it is easy to determine the RGB values of the background color
- * from the info_ptr struct. */
+ * from the info_ptr struct.
+ */
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
{
- png_ptr->background.index = buf[0];
- png_ptr->background.red = (png_uint_16)png_ptr->palette[buf[0]].red;
- png_ptr->background.green = (png_uint_16)png_ptr->palette[buf[0]].green;
- png_ptr->background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue;
- }
- else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */
- {
- png_ptr->background.red =
- png_ptr->background.green =
- png_ptr->background.blue =
- png_ptr->background.gray = png_get_uint_16(buf);
- }
- else
- {
- png_ptr->background.red = png_get_uint_16(buf);
- png_ptr->background.green = png_get_uint_16(buf + 2);
- png_ptr->background.blue = png_get_uint_16(buf + 4);
+ background.index = buf[0];
+
+ if (info_ptr && info_ptr->num_palette)
+ {
+ if (buf[0] >= info_ptr->num_palette)
+ {
+ png_chunk_benign_error(png_ptr, "invalid index");
+ return;
+ }
+
+ background.red = (png_uint_16)png_ptr->palette[buf[0]].red;
+ background.green = (png_uint_16)png_ptr->palette[buf[0]].green;
+ background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue;
+ }
+
+ else
+ background.red = background.green = background.blue = 0;
+
+ background.gray = 0;
+ }
+
+ else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */
+ {
+ background.index = 0;
+ background.red =
+ background.green =
+ background.blue =
+ background.gray = png_get_uint_16(buf);
}
- png_set_bKGD(png_ptr, info_ptr, &(png_ptr->background));
+ else
+ {
+ background.index = 0;
+ background.red = png_get_uint_16(buf);
+ background.green = png_get_uint_16(buf + 2);
+ background.blue = png_get_uint_16(buf + 4);
+ background.gray = 0;
+ }
+
+ png_set_bKGD(png_ptr, info_ptr, &background);
}
#endif
-#if defined(PNG_READ_hIST_SUPPORTED)
-void
-png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+#ifdef PNG_READ_hIST_SUPPORTED
+void /* PRIVATE */
+png_handle_hIST(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
- int num, i;
+ unsigned int num, i;
+ png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH];
- png_debug(1, "in png_handle_hIST\n");
+ 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;
- }
- else if (!(png_ptr->mode & PNG_HAVE_PLTE))
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ 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)
+
+ 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;
}
- if (length != (png_uint_32)(2 * png_ptr->num_palette))
+ num = length / 2 ;
+
+ 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;
}
- num = (int)length / 2;
- png_ptr->hist = (png_uint_16p)png_malloc(png_ptr,
- (png_uint_32)(num * sizeof (png_uint_16)));
- png_ptr->flags |= PNG_FLAG_FREE_HIST;
for (i = 0; i < num; i++)
{
png_byte buf[2];
png_crc_read(png_ptr, buf, 2);
- png_ptr->hist[i] = png_get_uint_16(buf);
+ readbuf[i] = png_get_uint_16(buf);
}
if (png_crc_finish(png_ptr, 0))
return;
- png_set_hIST(png_ptr, info_ptr, png_ptr->hist);
+ png_set_hIST(png_ptr, info_ptr, readbuf);
}
#endif
-#if defined(PNG_READ_pHYs_SUPPORTED)
-void
-png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+#ifdef PNG_READ_pHYs_SUPPORTED
+void /* PRIVATE */
+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;
int unit_type;
- png_debug(1, "in png_handle_pHYs\n");
+ 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)
+
+ 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;
}
png_crc_read(png_ptr, buf, 9);
+
if (png_crc_finish(png_ptr, 0))
return;
}
#endif
-#if defined(PNG_READ_oFFs_SUPPORTED)
-void
-png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+#ifdef PNG_READ_oFFs_SUPPORTED
+void /* PRIVATE */
+png_handle_oFFs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
png_byte buf[9];
- png_uint_32 offset_x, offset_y;
+ png_int_32 offset_x, offset_y;
int unit_type;
- png_debug(1, "in png_handle_oFFs\n");
+ 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)
+
+ 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;
}
png_crc_read(png_ptr, buf, 9);
+
if (png_crc_finish(png_ptr, 0))
return;
- offset_x = png_get_uint_32(buf);
- offset_y = png_get_uint_32(buf + 4);
+ offset_x = png_get_int_32(buf);
+ offset_y = png_get_int_32(buf + 4);
unit_type = buf[8];
png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type);
}
#endif
-#if defined(PNG_READ_pCAL_SUPPORTED)
-/* read the pCAL chunk (png-scivis-19970203) */
-void
-png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+#ifdef PNG_READ_pCAL_SUPPORTED
+/* Read the pCAL chunk (described in the PNG Extensions document) */
+void /* PRIVATE */
+png_handle_pCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
- png_charp purpose;
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\n");
+ 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)
+
+ 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 (%d bytes)\n",
- length + 1);
- purpose = (png_charp)png_malloc(png_ptr, length + 1);
- slength = (png_size_t)length;
- png_crc_read(png_ptr, (png_bytep)purpose, slength);
+ png_debug1(2, "Allocating and reading pCAL chunk data (%u bytes)",
+ length + 1);
- if (png_crc_finish(png_ptr, 0))
+ buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/);
+
+ if (buffer == NULL)
{
- png_free(png_ptr, purpose);
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of memory");
return;
}
- purpose[slength] = 0x00; /* null terminate the last string */
+ png_crc_read(png_ptr, buffer, length);
- png_debug(3, "Finding end of pCAL purpose string\n");
- for (buf = purpose; *buf != '\0'; buf++)
- /* empty loop */ ;
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ buffer[length] = 0; /* Null terminate the last string */
+
+ png_debug(3, "Finding end of pCAL purpose string");
+ for (buf = buffer; *buf; buf++)
+ /* Empty loop */ ;
- endptr = purpose + slength;
+ endptr = buffer + length;
/* We need to have at least 12 bytes after the purpose string
- in order to get the parameter information. */
+ * in order to get the parameter information.
+ */
if (endptr <= buf + 12)
{
- png_warning(png_ptr, "Invalid pCAL data");
- png_free(png_ptr, purpose);
+ png_chunk_benign_error(png_ptr, "invalid");
return;
}
- png_debug(3, "Reading pCAL X0, X1, type, nparams, and units\n");
+ png_debug(3, "Reading pCAL X0, X1, type, nparams, and units");
X0 = png_get_int_32((png_bytep)buf+1);
X1 = png_get_int_32((png_bytep)buf+5);
type = buf[9];
nparams = buf[10];
units = buf + 11;
- png_debug(3, "Checking pCAL equation type and number of parameters\n");
+ png_debug(3, "Checking pCAL equation type and number of parameters");
/* Check that we have the right number of parameters for known
- equation types. */
+ * equation types.
+ */
if ((type == PNG_EQUATION_LINEAR && nparams != 2) ||
(type == PNG_EQUATION_BASE_E && nparams != 3) ||
(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, purpose);
+ 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 != 0x00; buf++)
+ for (buf = units; *buf; buf++)
/* Empty loop to move past the units string. */ ;
- png_debug(3, "Allocating pCAL parameters array\n");
- params = (png_charpp)png_malloc(png_ptr, (png_uint_32)(nparams
- *sizeof(png_charp))) ;
+ png_debug(3, "Allocating pCAL parameters array");
+
+ params = png_voidcast(png_charpp, png_malloc_warn(png_ptr,
+ nparams * (sizeof (png_charp))));
+
+ if (params == NULL)
+ {
+ 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\n", i);
- for (params[i] = buf; *buf != 0x00 && buf <= endptr; buf++)
+ png_debug1(3, "Reading pCAL parameter %d", i);
+
+ 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, purpose);
png_free(png_ptr, params);
+ png_chunk_benign_error(png_ptr, "invalid data");
return;
}
}
- png_set_pCAL(png_ptr, info_ptr, purpose, 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, purpose);
png_free(png_ptr, params);
}
#endif
-#if defined(PNG_READ_tIME_SUPPORTED)
-void
-png_handle_tIME(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+#ifdef PNG_READ_sCAL_SUPPORTED
+/* Read the sCAL chunk */
+void /* PRIVATE */
+png_handle_sCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_bytep buffer;
+ png_size_t i;
+ int state;
+
+ png_debug(1, "in png_handle_sCAL");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ else if (png_ptr->mode & PNG_HAVE_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_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_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);
+
+ buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/);
+
+ if (buffer == NULL)
+ {
+ png_chunk_benign_error(png_ptr, "out of memory");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buffer, length);
+ buffer[length] = 0; /* Null terminate the last string */
+
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ /* Validate the unit. */
+ if (buffer[0] != 1 && buffer[0] != 2)
+ {
+ png_chunk_benign_error(png_ptr, "invalid unit");
+ return;
+ }
+
+ /* Validate the ASCII numbers, need two ASCII numbers separated by
+ * a '\0' and they need to fit exactly in the chunk data.
+ */
+ i = 1;
+ state = 0;
+
+ 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_chunk_benign_error(png_ptr, "non-positive width");
+
+ else
+ {
+ png_size_t heighti = i;
+
+ state = 0;
+ 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_chunk_benign_error(png_ptr, "non-positive height");
+
+ else
+ /* This is the (only) success case. */
+ png_set_sCAL_s(png_ptr, info_ptr, buffer[0],
+ (png_charp)buffer+1, (png_charp)buffer+heighti);
+ }
+}
+#endif
+
+#ifdef PNG_READ_tIME_SUPPORTED
+void /* PRIVATE */
+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\n");
+ png_debug(1, "in png_handle_tIME");
if (!(png_ptr->mode & PNG_HAVE_IHDR))
- png_error(png_ptr, "Out of place tIME chunk");
- else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_tIME)
+ 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;
}
png_crc_read(png_ptr, buf, 7);
+
if (png_crc_finish(png_ptr, 0))
return;
}
#endif
-#if defined(PNG_READ_tEXt_SUPPORTED)
+#ifdef PNG_READ_tEXt_SUPPORTED
/* Note: this does not properly handle chunks that are > 64K under DOS */
-void
-png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+void /* PRIVATE */
+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;
- png_debug(1, "in png_handle_tEXt\n");
+ png_debug(1, "in png_handle_tEXt");
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ if (png_ptr->user_chunk_cache_max != 0)
+ {
+ if (png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (--png_ptr->user_chunk_cache_max == 1)
+ {
+ 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
- key = (png_charp)png_malloc(png_ptr, length + 1);
- slength = (png_size_t)length;
- png_crc_read(png_ptr, (png_bytep)key, slength);
+ buffer = png_read_buffer(png_ptr, length+1, 1/*warn*/);
- if (png_crc_finish(png_ptr, skip))
+ if (buffer == NULL)
{
- png_free(png_ptr, key);
- return;
+ png_chunk_benign_error(png_ptr, "out of memory");
+ return;
}
- key[slength] = 0x00;
+ png_crc_read(png_ptr, buffer, length);
+
+ if (png_crc_finish(png_ptr, skip))
+ return;
+
+ key = (png_charp)buffer;
+ key[length] = 0;
for (text = key; *text; text++)
- /* empty loop to find end of key */ ;
+ /* Empty loop to find end of key */ ;
- if (text != key + slength)
+ if (text != key + length)
text++;
- text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
- text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
- text_ptr->key = key;
- text_ptr->text = 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);
- png_set_text(png_ptr, info_ptr, text_ptr, 1);
-
- png_free(png_ptr, text_ptr);
+ if (png_set_text_2(png_ptr, info_ptr, &text_info, 1))
+ png_warning(png_ptr, "Insufficient memory to process text chunk");
}
#endif
-#if defined(PNG_READ_zTXt_SUPPORTED)
-/* note: this does not correctly handle chunks that are > 64K under DOS */
-void
-png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+#ifdef PNG_READ_zTXt_SUPPORTED
+/* Note: this does not correctly handle chunks that are > 64K under DOS */
+void /* PRIVATE */
+png_handle_zTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
{
- static char msg[] = "Error decoding zTXt chunk";
- png_textp text_ptr;
- png_charp key;
- png_charp text;
- int comp_type = PNG_TEXT_COMPRESSION_NONE;
- png_size_t slength;
+ png_const_charp errmsg = NULL;
+ png_bytep buffer;
+ png_uint_32 keyword_length;
- png_debug(1, "in png_handle_zTXt\n");
+ png_debug(1, "in png_handle_zTXt");
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ if (png_ptr->user_chunk_cache_max != 0)
+ {
+ if (png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (--png_ptr->user_chunk_cache_max == 1)
+ {
+ 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)
+ buffer = png_read_buffer(png_ptr, length, 2/*silent*/);
+
+ if (buffer == NULL)
{
- png_warning(png_ptr,"zTXt chunk too large to fit in memory");
- png_crc_finish(png_ptr, length);
- return;
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of memory");
+ return;
}
-#endif
- key = (png_charp)png_malloc(png_ptr, length + 1);
- slength = (png_size_t)length;
- png_crc_read(png_ptr, (png_bytep)key, slength);
+ png_crc_read(png_ptr, buffer, length);
+
if (png_crc_finish(png_ptr, 0))
- {
- png_free(png_ptr, key);
return;
+
+ /* 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 */ ;
+
+ if (keyword_length > 79 || keyword_length < 1)
+ errmsg = "bad keyword";
+
+ /* 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
+ {
+ png_alloc_size_t uncompressed_length = PNG_SIZE_MAX;
+
+ /* 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;
+
+ /* 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";
+ }
+
+ else
+ errmsg = png_ptr->zstream.msg;
}
- key[slength] = 0x00;
+ if (errmsg != NULL)
+ png_chunk_benign_error(png_ptr, errmsg);
+}
+#endif
- for (text = key; *text; text++)
- /* empty loop */ ;
+#ifdef PNG_READ_iTXt_SUPPORTED
+/* Note: this does not correctly handle chunks that are > 64K under DOS */
+void /* PRIVATE */
+png_handle_iTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_const_charp errmsg = NULL;
+ png_bytep buffer;
+ png_uint_32 prefix_length;
+
+ png_debug(1, "in png_handle_iTXt");
- /* zTXt must have some text after the keyword */
- if (text == key + slength)
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ if (png_ptr->user_chunk_cache_max != 0)
{
- png_warning(png_ptr, "Zero length zTXt chunk");
+ if (png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (--png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "no space in chunk cache");
+ return;
+ }
}
- else if ((comp_type = *(++text)) == PNG_TEXT_COMPRESSION_zTXt)
+#endif
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_chunk_error(png_ptr, "missing IHDR");
+
+ if (png_ptr->mode & PNG_HAVE_IDAT)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+ buffer = png_read_buffer(png_ptr, length+1, 1/*warn*/);
+
+ if (buffer == NULL)
{
- png_size_t text_size, key_size;
- text++;
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of memory");
+ return;
+ }
- png_ptr->zstream.next_in = (png_bytep)text;
- png_ptr->zstream.avail_in = (uInt)(length - (text - key));
- png_ptr->zstream.next_out = png_ptr->zbuf;
- png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+ png_crc_read(png_ptr, buffer, length);
- key_size = (png_size_t)(text - key);
- text_size = 0;
- text = NULL;
+ if (png_crc_finish(png_ptr, 0))
+ return;
- while (png_ptr->zstream.avail_in)
- {
- int ret;
+ /* First the keyword. */
+ for (prefix_length=0;
+ prefix_length < length && buffer[prefix_length] != 0;
+ ++prefix_length)
+ /* Empty loop */ ;
- ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
- if (ret != Z_OK && ret != Z_STREAM_END)
- {
- if (png_ptr->zstream.msg != NULL)
- png_warning(png_ptr, png_ptr->zstream.msg);
- else
- png_warning(png_ptr, msg);
- inflateReset(&png_ptr->zstream);
- png_ptr->zstream.avail_in = 0;
+ /* Perform a basic check on the keyword length here. */
+ if (prefix_length > 79 || prefix_length < 1)
+ errmsg = "bad keyword";
- if (text == NULL)
- {
- text_size = key_size + sizeof(msg) + 1;
- text = (png_charp)png_malloc(png_ptr, (png_uint_32)text_size);
- png_memcpy(text, key, key_size);
- }
+ /* 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";
- text[text_size - 1] = 0x00;
+ else if (buffer[prefix_length+1] == 0 ||
+ (buffer[prefix_length+1] == 1 &&
+ buffer[prefix_length+2] == PNG_COMPRESSION_TYPE_BASE))
+ {
+ int compressed = buffer[prefix_length+1] != 0;
+ png_uint_32 language_offset, translated_keyword_offset;
+ png_alloc_size_t uncompressed_length = 0;
- /* Copy what we can of the error message into the text chunk */
- text_size = (png_size_t)(slength - (text - key) - 1);
- text_size = sizeof(msg) > text_size ? text_size : sizeof(msg);
- png_memcpy(text + key_size, msg, text_size + 1);
- break;
- }
- if (!png_ptr->zstream.avail_out || ret == Z_STREAM_END)
- {
- if (text == NULL)
- {
- text = (png_charp)png_malloc(png_ptr,
- (png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out
- + key_size + 1));
- png_memcpy(text + key_size, png_ptr->zbuf,
- png_ptr->zbuf_size - png_ptr->zstream.avail_out);
- png_memcpy(text, key, key_size);
- text_size = key_size + png_ptr->zbuf_size -
- png_ptr->zstream.avail_out;
- *(text + text_size) = 0x00;
- }
- else
- {
- png_charp tmp;
-
- tmp = text;
- text = (png_charp)png_malloc(png_ptr, (png_uint_32)(text_size +
- png_ptr->zbuf_size - png_ptr->zstream.avail_out + 1));
- png_memcpy(text, tmp, text_size);
- png_free(png_ptr, tmp);
- png_memcpy(text + text_size, png_ptr->zbuf,
- (png_ptr->zbuf_size - png_ptr->zstream.avail_out));
- text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
- *(text + text_size) = 0x00;
- }
- if (ret != Z_STREAM_END)
- {
- png_ptr->zstream.next_out = png_ptr->zbuf;
- png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
- }
- else
- {
- break;
- }
- }
+ /* Now the language tag */
+ prefix_length += 3;
+ language_offset = prefix_length;
+
+ for (; prefix_length < length && buffer[prefix_length] != 0;
+ ++prefix_length)
+ /* Empty loop */ ;
+
+ /* WARNING: the length may be invalid here, this is checked below. */
+ translated_keyword_offset = ++prefix_length;
+
+ for (; prefix_length < length && buffer[prefix_length] != 0;
+ ++prefix_length)
+ /* 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;
+
+ if (!compressed && prefix_length <= length)
+ uncompressed_length = length - prefix_length;
+
+ else if (compressed && prefix_length < length)
+ {
+ uncompressed_length = PNG_SIZE_MAX;
+
+ /* 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;
+
+ else
+ errmsg = png_ptr->zstream.msg;
}
- inflateReset(&png_ptr->zstream);
- png_ptr->zstream.avail_in = 0;
+ else
+ errmsg = "truncated";
- png_free(png_ptr, key);
- key = text;
- text += key_size;
- }
- else /* if (comp_type >= PNG_TEXT_COMPRESSION_LAST) */
- {
- png_size_t text_size;
-#if !defined(PNG_NO_STDIO)
- char umsg[50];
+ if (errmsg == NULL)
+ {
+ png_text text;
- sprintf(umsg, "Unknown zTXt compression type %d", comp_type);
- png_warning(png_ptr, umsg);
-#else
- png_warning(png_ptr, "Unknown zTXt compression type");
-#endif
+ buffer[uncompressed_length+prefix_length] = 0;
- /* Copy what we can of the error message into the text chunk */
- text_size = (png_size_t)(slength - (text - key) - 1);
- text_size = sizeof(msg) > text_size ? text_size : sizeof(msg);
- png_memcpy(text, msg, text_size + 1);
- }
+ if (compressed)
+ text.compression = PNG_ITXT_COMPRESSION_NONE;
+
+ else
+ text.compression = PNG_ITXT_COMPRESSION_zTXt;
+
+ 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;
- text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
- text_ptr->compression = comp_type;
- text_ptr->key = key;
- text_ptr->text = text;
+ if (png_set_text_2(png_ptr, info_ptr, &text, 1))
+ errmsg = "insufficient memory";
+ }
+ }
- png_set_text(png_ptr, info_ptr, text_ptr, 1);
+ else
+ errmsg = "bad compression info";
- png_free(png_ptr, text_ptr);
+ 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. */
-void
-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_debug(1, "in png_handle_unknown\n");
+ png_alloc_size_t limit = PNG_SIZE_MAX;
- /* In the future we can have code here that calls user-supplied
- * callback functions for unknown chunks before they are ignored or
- * cause an error.
- */
- png_check_chunk_name(png_ptr, png_ptr->chunk_name);
+ if (png_ptr->unknown_chunk.data != NULL)
+ {
+ png_free(png_ptr, png_ptr->unknown_chunk.data);
+ png_ptr->unknown_chunk.data = NULL;
+ }
- if (!(png_ptr->chunk_name[0] & 0x20))
+# 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)
{
- png_chunk_error(png_ptr, "unknown critical chunk");
+ 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*/;
- /* to quiet compiler warnings about unused info_ptr */
- if (info_ptr == NULL)
- return;
+ if (length == 0)
+ png_ptr->unknown_chunk.data = NULL;
+
+ else
+ {
+ /* Do a 'warn' here - it is handled below. */
+ png_ptr->unknown_chunk.data = png_voidcast(png_bytep,
+ png_malloc_warn(png_ptr, length));
+ }
}
- if (png_ptr->mode & PNG_HAVE_IDAT)
- png_ptr->mode |= PNG_AFTER_IDAT;
+ if (png_ptr->unknown_chunk.data == NULL && length > 0)
+ {
+ /* 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;
+ }
+
+ else
+ {
+ 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
+
+ /* 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)
+ {
+ 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");
+
+ 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;
+ }
+ }
+
+ 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
+ {
+ /* 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
+
+ {
+ /* 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");
+
+ png_crc_finish(png_ptr, length);
+ }
+# endif
+
+# 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)
+ {
+ 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;
+ 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
+
+ /* 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 /* !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 */
+ /* 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.
- This function can't have the "critical chunk check" incorporated
- into it, since in the future we will need to be able to call user
- functions to handle unknown critical chunks after we check that
- the chunk name itself is valid. */
+ * This function can't have the "critical chunk check" incorporated
+ * into it, since in the future we will need to be able to call user
+ * functions to handle unknown critical chunks after we check that
+ * the chunk name itself is valid.
+ */
-#define isnonalpha(c) ((c) < 41 || (c) > 122 || ((c) > 90 && (c) < 97))
+/* Bit hacking: the test for an invalid byte in the 4 byte chunk name is:
+ *
+ * ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
+ */
-void
-png_check_chunk_name(png_structp png_ptr, png_bytep chunk_name)
+void /* PRIVATE */
+png_check_chunk_name(png_structrp png_ptr, png_uint_32 chunk_name)
{
- png_debug(1, "in png_check_chunk_name\n");
- if (isnonalpha(chunk_name[0]) || isnonalpha(chunk_name[1]) ||
- isnonalpha(chunk_name[2]) || isnonalpha(chunk_name[3]))
+ int i;
+
+ png_debug(1, "in png_check_chunk_name");
+
+ for (i=1; i<=4; ++i)
{
- png_chunk_error(png_ptr, "invalid chunk type");
+ int c = chunk_name & 0xff;
+
+ if (c < 65 || c > 122 || (c > 90 && c < 97))
+ png_chunk_error(png_ptr, "invalid chunk type");
+
+ chunk_name >>= 8;
}
}
-/* Combines the row recently read in with the previous 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 pixels 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. */
-void
-png_combine_row(png_structp png_ptr, png_bytep row,
- int 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_const_structrp png_ptr, png_bytep dp, int display)
{
- png_debug(1,"in png_combine_row\n");
- if (mask == 0xff)
+ unsigned int pixel_depth = png_ptr->transformed_pixel_depth;
+ png_const_bytep sp = png_ptr->row_buf + 1;
+ png_uint_32 row_width = png_ptr->width;
+ unsigned int pass = png_ptr->pass;
+ png_bytep end_ptr = 0;
+ png_byte end_byte = 0;
+ unsigned int end_mask;
+
+ png_debug(1, "in png_combine_row");
+
+ /* Added in 1.5.6: it should not be possible to enter this routine until at
+ * least one row has been read from the PNG data and transformed.
+ */
+ if (pixel_depth == 0)
+ png_error(png_ptr, "internal row logic error");
+
+ /* Added in 1.5.4: the pixel depth should match the information returned by
+ * any call to png_read_update_info at this point. Do not continue if we got
+ * this wrong.
+ */
+ if (png_ptr->info_rowbytes != 0 && png_ptr->info_rowbytes !=
+ PNG_ROWBYTES(pixel_depth, row_width))
+ png_error(png_ptr, "internal row size calculation error");
+
+ /* Don't expect this to ever happen: */
+ if (row_width == 0)
+ png_error(png_ptr, "internal row width error");
+
+ /* Preserve the last byte in cases where only part of it will be overwritten,
+ * the multiply below may overflow, we don't care because ANSI-C guarantees
+ * we get the low bits.
+ */
+ end_mask = (pixel_depth * row_width) & 7;
+ if (end_mask != 0)
{
- png_memcpy(row, png_ptr->row_buf + 1,
- (png_size_t)((png_ptr->width *
- png_ptr->row_info.pixel_depth + 7) >> 3));
+ /* end_ptr == NULL is a flag to say do nothing */
+ end_ptr = dp + PNG_ROWBYTES(pixel_depth, row_width) - 1;
+ end_byte = *end_ptr;
+# ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if (png_ptr->transformations & PNG_PACKSWAP) /* little-endian byte */
+ end_mask = 0xff << end_mask;
+
+ else /* big-endian byte */
+# endif
+ end_mask = 0xff >> end_mask;
+ /* end_mask is now the bits to *keep* from the destination row */
}
- else
+
+ /* 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
+ * pass.
+ */
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE) &&
+ pass < 6 && (display == 0 ||
+ /* The following copies everything for 'display' on passes 0, 2 and 4. */
+ (display == 1 && (pass & 1) != 0)))
{
- switch (png_ptr->row_info.pixel_depth)
+ /* Narrow images may have no bits in a pass; the caller should handle
+ * this, but this test is cheap:
+ */
+ if (row_width <= PNG_PASS_START_COL(pass))
+ return;
+
+ if (pixel_depth < 8)
{
- case 1:
+ /* 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
+ * make this work the PACKSWAP option must be taken into account - it
+ * simply requires the pixels to be reversed in each byte.
+ *
+ * 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 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
+ * not) of the pixels in each byte.
+ *
+ * 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.
+ *
+ * The following defines allow generation of compile time constant bit
+ * masks for each pixel depth and each possibility of swapped or not
+ * swapped bytes. Pass 'p' is in the range 0..6; 'x', a pixel index,
+ * is in the range 0..7; and the result is 1 if the pixel is to be
+ * copied in the pass, 0 if not. 'S' is for the sparkle method, 'B'
+ * for the block method.
+ *
+ * With some compilers a compile time expression of the general form:
+ *
+ * (shift >= 32) ? (a >> (shift-32)) : (b >> shift)
+ *
+ * Produces warnings with values of 'shift' in the range 33 to 63
+ * because the right hand side of the ?: expression is evaluated by
+ * 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 destabilizing the code during the release process.
+ */
+# if PNG_USE_COMPILE_TIME_MASKS
+# define PNG_LSR(x,s) ((x)>>((s) & 0x1f))
+# define PNG_LSL(x,s) ((x)<<((s) & 0x1f))
+# else
+# define PNG_LSR(x,s) ((x)>>(s))
+# define PNG_LSL(x,s) ((x)<<(s))
+# endif
+# define S_COPY(p,x) (((p)<4 ? PNG_LSR(0x80088822,(3-(p))*8+(7-(x))) :\
+ PNG_LSR(0xaa55ff00,(7-(p))*8+(7-(x)))) & 1)
+# define B_COPY(p,x) (((p)<4 ? PNG_LSR(0xff0fff33,(3-(p))*8+(7-(x))) :\
+ PNG_LSR(0xff55ff00,(7-(p))*8+(7-(x)))) & 1)
+
+ /* Return a mask for pass 'p' pixel 'x' at depth 'd'. The mask is
+ * little endian - the first pixel is at bit 0 - however the extra
+ * parameter 's' can be set to cause the mask position to be swapped
+ * within each byte, to match the PNG format. This is done by XOR of
+ * the shift with 7, 6 or 4 for bit depths 1, 2 and 4.
+ */
+# define PIXEL_MASK(p,x,d,s) \
+ (PNG_LSL(((PNG_LSL(1U,(d)))-1),(((x)*(d))^((s)?8-(d):0))))
+
+ /* Hence generate the appropriate 'block' or 'sparkle' pixel copy mask.
+ */
+# define S_MASKx(p,x,d,s) (S_COPY(p,x)?PIXEL_MASK(p,x,d,s):0)
+# define B_MASKx(p,x,d,s) (B_COPY(p,x)?PIXEL_MASK(p,x,d,s):0)
+
+ /* Combine 8 of these to get the full mask. For the 1-bpp and 2-bpp
+ * cases the result needs replicating, for the 4-bpp case the above
+ * generates a full 32 bits.
+ */
+# define MASK_EXPAND(m,d) ((m)*((d)==1?0x01010101:((d)==2?0x00010001:1)))
+
+# define S_MASK(p,d,s) MASK_EXPAND(S_MASKx(p,0,d,s) + S_MASKx(p,1,d,s) +\
+ S_MASKx(p,2,d,s) + S_MASKx(p,3,d,s) + S_MASKx(p,4,d,s) +\
+ S_MASKx(p,5,d,s) + S_MASKx(p,6,d,s) + S_MASKx(p,7,d,s), d)
+
+# define B_MASK(p,d,s) MASK_EXPAND(B_MASKx(p,0,d,s) + B_MASKx(p,1,d,s) +\
+ B_MASKx(p,2,d,s) + B_MASKx(p,3,d,s) + B_MASKx(p,4,d,s) +\
+ B_MASKx(p,5,d,s) + B_MASKx(p,6,d,s) + B_MASKx(p,7,d,s), d)
+
+#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
+ * 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),\
+ S_MASK(3,d,s), S_MASK(4,d,s), S_MASK(5,d,s) }
+
+# define B_MASKS(d,s) { B_MASK(1,d,s), S_MASK(3,d,s), S_MASK(5,d,s) }
+
+# define DEPTH_INDEX(d) ((d)==1?0:((d)==2?1:2))
+
+ /* 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] =
{
- png_bytep sp;
- png_bytep dp;
- int s_inc, s_start, s_end;
- int m;
- int shift;
- png_uint_32 i;
-
- sp = png_ptr->row_buf + 1;
- dp = row;
- m = 0x80;
-#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+ /* 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 */
+ { S_MASKS(1,1), S_MASKS(2,1), S_MASKS(4,1) }
+ };
+
+ /* 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] =
+ {
+ /* 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 */
+ { B_MASKS(1,1), B_MASKS(2,1), B_MASKS(4,1) }
+ };
+
+# define MASK(pass,depth,display,png)\
+ ((display)?display_mask[png][DEPTH_INDEX(depth)][pass>>1]:\
+ row_mask[png][DEPTH_INDEX(depth)][pass])
+
+#else /* !PNG_USE_COMPILE_TIME_MASKS */
+ /* This is the runtime alternative: it seems unlikely that this will
+ * ever be either smaller or faster than the compile time approach.
+ */
+# define MASK(pass,depth,display,png)\
+ ((display)?B_MASK(pass,depth,png):S_MASK(pass,depth,png))
+#endif /* !PNG_USE_COMPILE_TIME_MASKS */
+
+ /* Use the appropriate mask to copy the required bits. In some cases
+ * the byte mask will be 0 or 0xff, optimize these cases. row_width is
+ * the number of pixels, but the code copies bytes, so it is necessary
+ * to special case the end.
+ */
+ png_uint_32 pixels_per_byte = 8 / pixel_depth;
+ png_uint_32 mask;
+
+# ifdef PNG_READ_PACKSWAP_SUPPORTED
if (png_ptr->transformations & PNG_PACKSWAP)
- {
- s_start = 0;
- s_end = 7;
- s_inc = 1;
- }
+ mask = MASK(pass, pixel_depth, display, 0);
+
else
-#endif
+# endif
+ mask = MASK(pass, pixel_depth, display, 1);
+
+ for (;;)
+ {
+ png_uint_32 m;
+
+ /* It doesn't matter in the following if png_uint_32 has more than
+ * 32 bits because the high bits always match those in m<<24; it is,
+ * however, essential to use OR here, not +, because of this.
+ */
+ m = mask;
+ mask = (m >> 8) | (m << 24); /* rotate right to good compilers */
+ m &= 0xff;
+
+ if (m != 0) /* something to copy */
{
- s_start = 7;
- s_end = 0;
- s_inc = -1;
+ if (m != 0xff)
+ *dp = (png_byte)((*dp & ~m) | (*sp & m));
+ else
+ *dp = *sp;
}
- shift = s_start;
+ /* NOTE: this may overwrite the last byte with garbage if the image
+ * is not an exact number of bytes wide; libpng has always done
+ * this.
+ */
+ if (row_width <= pixels_per_byte)
+ break; /* May need to restore part of the last byte */
- for (i = 0; i < png_ptr->width; i++)
- {
- if (m & mask)
- {
- int value;
+ row_width -= pixels_per_byte;
+ ++dp;
+ ++sp;
+ }
+ }
- value = (*sp >> shift) & 0x1;
- *dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
- *dp |= (png_byte)(value << shift);
- }
+ else /* pixel_depth >= 8 */
+ {
+ unsigned int bytes_to_copy, bytes_to_jump;
- if (shift == s_end)
- {
- shift = s_start;
- sp++;
- dp++;
- }
- else
- shift += s_inc;
+ /* Validate the depth - it must be a multiple of 8 */
+ if (pixel_depth & 7)
+ png_error(png_ptr, "invalid user transform pixel depth");
- if (m == 1)
- m = 0x80;
- else
- m >>= 1;
- }
- break;
- }
- case 2:
+ pixel_depth >>= 3; /* now in bytes */
+ row_width *= pixel_depth;
+
+ /* Regardless of pass number the Adam 7 interlace always results in a
+ * fixed number of pixels to copy then to skip. There may be a
+ * different number of pixels to skip at the start though.
+ */
{
- png_bytep sp;
- png_bytep dp;
- int s_start, s_end, s_inc;
- int m;
- int shift;
- png_uint_32 i;
- int value;
+ unsigned int offset = PNG_PASS_START_COL(pass) * pixel_depth;
- sp = png_ptr->row_buf + 1;
- dp = row;
- m = 0x80;
-#if defined(PNG_READ_PACKSWAP_SUPPORTED)
- if (png_ptr->transformations & PNG_PACKSWAP)
- {
- s_start = 0;
- s_end = 6;
- s_inc = 2;
- }
- else
-#endif
- {
- s_start = 6;
- s_end = 0;
- s_inc = -2;
- }
+ row_width -= offset;
+ dp += offset;
+ sp += offset;
+ }
- shift = s_start;
+ /* Work out the bytes to copy. */
+ if (display)
+ {
+ /* When doing the 'block' algorithm the pixel in the pass gets
+ * replicated to adjacent pixels. This is why the even (0,2,4,6)
+ * passes are skipped above - the entire expanded row is copied.
+ */
+ bytes_to_copy = (1<<((6-pass)>>1)) * pixel_depth;
+
+ /* But don't allow this number to exceed the actual row width. */
+ if (bytes_to_copy > row_width)
+ bytes_to_copy = row_width;
+ }
- for (i = 0; i < png_ptr->width; i++)
- {
- if (m & mask)
+ else /* normal row; Adam7 only ever gives us one pixel to copy. */
+ bytes_to_copy = pixel_depth;
+
+ /* In Adam7 there is a constant offset between where the pixels go. */
+ bytes_to_jump = PNG_PASS_COL_OFFSET(pass) * pixel_depth;
+
+ /* And simply copy these bytes. Some optimization is possible here,
+ * depending on the value of 'bytes_to_copy'. Special case the low
+ * byte counts, which we know to be frequent.
+ *
+ * Notice that these cases all 'return' rather than 'break' - this
+ * avoids an unnecessary test on whether to restore the last byte
+ * below.
+ */
+ switch (bytes_to_copy)
+ {
+ case 1:
+ for (;;)
{
- value = (*sp >> shift) & 0x3;
- *dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
- *dp |= (png_byte)(value << shift);
+ *dp = *sp;
+
+ if (row_width <= bytes_to_jump)
+ return;
+
+ dp += bytes_to_jump;
+ sp += bytes_to_jump;
+ row_width -= bytes_to_jump;
}
- if (shift == s_end)
+ case 2:
+ /* There is a possibility of a partial copy at the end here; this
+ * slows the code down somewhat.
+ */
+ do
{
- shift = s_start;
- sp++;
- dp++;
+ dp[0] = sp[0], dp[1] = sp[1];
+
+ if (row_width <= bytes_to_jump)
+ return;
+
+ sp += bytes_to_jump;
+ dp += bytes_to_jump;
+ row_width -= bytes_to_jump;
}
- else
- shift += s_inc;
- if (m == 1)
- m = 0x80;
- else
- m >>= 1;
- }
- break;
- }
- case 4:
- {
- png_bytep sp;
- png_bytep dp;
- int s_start, s_end, s_inc;
- int m;
- int shift;
- png_uint_32 i;
- int value;
+ while (row_width > 1);
- sp = png_ptr->row_buf + 1;
- dp = row;
- m = 0x80;
-#if defined(PNG_READ_PACKSWAP_SUPPORTED)
- if (png_ptr->transformations & PNG_PACKSWAP)
- {
- s_start = 0;
- s_end = 4;
- s_inc = 4;
- }
- else
-#endif
- {
- s_start = 4;
- s_end = 0;
- s_inc = -4;
- }
- shift = s_start;
+ /* And there can only be one byte left at this point: */
+ *dp = *sp;
+ return;
- for (i = 0; i < png_ptr->width; i++)
- {
- if (m & mask)
+ case 3:
+ /* This can only be the RGB case, so each copy is exactly one
+ * pixel and it is not necessary to check for a partial copy.
+ */
+ for(;;)
{
- value = (*sp >> shift) & 0xf;
- *dp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
- *dp |= (png_byte)(value << shift);
+ dp[0] = sp[0], dp[1] = sp[1], dp[2] = sp[2];
+
+ if (row_width <= bytes_to_jump)
+ return;
+
+ sp += bytes_to_jump;
+ dp += bytes_to_jump;
+ row_width -= bytes_to_jump;
}
- if (shift == s_end)
+ default:
+#if PNG_ALIGN_TYPE != PNG_ALIGN_NONE
+ /* 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 memcpy there.
+ */
+ 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)
{
- shift = s_start;
- sp++;
- dp++;
- }
- else
- shift += s_inc;
- if (m == 1)
- m = 0x80;
- else
- m >>= 1;
- }
- break;
- }
- default:
- {
- png_bytep sp;
- png_bytep dp;
- png_size_t pixel_bytes;
- png_uint_32 i;
- png_byte m;
+ /* 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)
+ {
+ 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
+ {
+ size_t c = bytes_to_copy;
+ do
+ {
+ *dp32++ = *sp32++;
+ c -= (sizeof (png_uint_32));
+ }
+ while (c > 0);
+
+ if (row_width <= bytes_to_jump)
+ return;
+
+ dp32 += skip;
+ sp32 += skip;
+ row_width -= bytes_to_jump;
+ }
+ while (bytes_to_copy <= row_width);
+
+ /* Get to here when the row_width truncates the final copy.
+ * There will be 1-3 bytes left to copy, so don't try the
+ * 16-bit loop below.
+ */
+ dp = (png_bytep)dp32;
+ sp = (png_const_bytep)sp32;
+ do
+ *dp++ = *sp++;
+ while (--row_width > 0);
+ return;
+ }
- pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
+ /* Else do it in 16-bit quantities, but only if the size is
+ * not too large.
+ */
+ else
+ {
+ 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
+ {
+ size_t c = bytes_to_copy;
+ do
+ {
+ *dp16++ = *sp16++;
+ c -= (sizeof (png_uint_16));
+ }
+ while (c > 0);
+
+ if (row_width <= bytes_to_jump)
+ return;
+
+ dp16 += skip;
+ sp16 += skip;
+ row_width -= bytes_to_jump;
+ }
+ while (bytes_to_copy <= row_width);
+
+ /* End of row - 1 byte left, bytes_to_copy > row_width: */
+ dp = (png_bytep)dp16;
+ sp = (png_const_bytep)sp16;
+ do
+ *dp++ = *sp++;
+ while (--row_width > 0);
+ return;
+ }
+ }
+#endif /* PNG_ALIGN_ code */
- sp = png_ptr->row_buf + 1;
- dp = row;
- m = 0x80;
- for (i = 0; i < png_ptr->width; i++)
- {
- if (m & mask)
+ /* The true default - use a memcpy: */
+ for (;;)
{
- png_memcpy(dp, sp, pixel_bytes);
- }
+ memcpy(dp, sp, bytes_to_copy);
- sp += pixel_bytes;
- dp += pixel_bytes;
+ if (row_width <= bytes_to_jump)
+ return;
- if (m == 1)
- m = 0x80;
- else
- m >>= 1;
- }
- break;
+ sp += bytes_to_jump;
+ dp += bytes_to_jump;
+ row_width -= bytes_to_jump;
+ if (bytes_to_copy > row_width)
+ bytes_to_copy = row_width;
+ }
}
- }
+
+ /* NOT REACHED*/
+ } /* pixel_depth >= 8 */
+
+ /* Here if pixel_depth < 8 to check 'end_ptr' below. */
}
+ else
+#endif
+
+ /* 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.)
+ */
+ memcpy(dp, sp, PNG_ROWBYTES(pixel_depth, row_width));
+
+ /* Restore the overwritten bits from the last byte if necessary. */
+ if (end_ptr != NULL)
+ *end_ptr = (png_byte)((end_byte & end_mask) | (*end_ptr & ~end_mask));
}
-#if defined(PNG_READ_INTERLACING_SUPPORTED)
-void
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+void /* PRIVATE */
png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
- png_uint_32 transformations)
+ png_uint_32 transformations /* Because these may affect the byte layout */)
{
- png_debug(1,"in png_do_read_interlace\n");
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+ /* Offset to next interlace block */
+ static PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+ png_debug(1, "in png_do_read_interlace");
if (row != NULL && row_info != NULL)
{
png_uint_32 final_width;
{
case 1:
{
- png_bytep sp, dp;
+ png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3);
+ png_bytep dp = row + (png_size_t)((final_width - 1) >> 3);
int sshift, dshift;
int s_start, s_end, s_inc;
+ int jstop = png_pass_inc[pass];
png_byte v;
png_uint_32 i;
int j;
- sp = row + (png_size_t)((row_info->width - 1) >> 3);
- dp = row + (png_size_t)((final_width - 1) >> 3);
-#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
if (transformations & PNG_PACKSWAP)
{
- sshift = (int)((row_info->width + 7) & 7);
- dshift = (int)((final_width + 7) & 7);
+ sshift = (int)((row_info->width + 7) & 0x07);
+ dshift = (int)((final_width + 7) & 0x07);
s_start = 7;
s_end = 0;
s_inc = -1;
}
+
else
#endif
{
- sshift = 7 - (int)((row_info->width + 7) & 7);
- dshift = 7 - (int)((final_width + 7) & 7);
+ sshift = 7 - (int)((row_info->width + 7) & 0x07);
+ dshift = 7 - (int)((final_width + 7) & 0x07);
s_start = 0;
s_end = 7;
s_inc = 1;
}
- for (i = row_info->width; i; i--)
+ for (i = 0; i < row_info->width; i++)
{
- v = (png_byte)((*sp >> sshift) & 0x1);
- for (j = 0; j < png_pass_inc[pass]; j++)
+ 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)
{
dshift = s_start;
dp--;
}
+
else
dshift += s_inc;
}
+
if (sshift == s_end)
{
sshift = s_start;
sp--;
}
+
else
sshift += s_inc;
}
break;
}
+
case 2:
{
- png_bytep sp, dp;
+ png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2);
+ png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2);
int sshift, dshift;
int s_start, s_end, s_inc;
+ int jstop = png_pass_inc[pass];
png_uint_32 i;
- sp = row + (png_uint_32)((row_info->width - 1) >> 2);
- dp = row + (png_uint_32)((final_width - 1) >> 2);
-#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
if (transformations & PNG_PACKSWAP)
{
- sshift = (int)(((row_info->width + 3) & 3) << 1);
- dshift = (int)(((final_width + 3) & 3) << 1);
+ sshift = (int)(((row_info->width + 3) & 0x03) << 1);
+ dshift = (int)(((final_width + 3) & 0x03) << 1);
s_start = 6;
s_end = 0;
s_inc = -2;
}
+
else
#endif
{
- sshift = (int)((3 - ((row_info->width + 3) & 3)) << 1);
- dshift = (int)((3 - ((final_width + 3) & 3)) << 1);
+ sshift = (int)((3 - ((row_info->width + 3) & 0x03)) << 1);
+ dshift = (int)((3 - ((final_width + 3) & 0x03)) << 1);
s_start = 0;
s_end = 6;
s_inc = 2;
}
- for (i = row_info->width; i; i--)
+ for (i = 0; i < row_info->width; i++)
{
png_byte v;
int j;
- v = (png_byte)((*sp >> sshift) & 0x3);
- for (j = 0; j < png_pass_inc[pass]; j++)
+ 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)
{
dshift = s_start;
dp--;
}
+
else
dshift += s_inc;
}
+
if (sshift == s_end)
{
sshift = s_start;
sp--;
}
+
else
sshift += s_inc;
}
break;
}
+
case 4:
{
- png_bytep sp, dp;
+ png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1);
+ png_bytep dp = row + (png_size_t)((final_width - 1) >> 1);
int sshift, dshift;
int s_start, s_end, s_inc;
png_uint_32 i;
+ int jstop = png_pass_inc[pass];
- sp = row + (png_size_t)((row_info->width - 1) >> 1);
- dp = row + (png_size_t)((final_width - 1) >> 1);
-#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
if (transformations & PNG_PACKSWAP)
{
- sshift = (int)(((row_info->width + 1) & 1) << 2);
- dshift = (int)(((final_width + 1) & 1) << 2);
+ sshift = (int)(((row_info->width + 1) & 0x01) << 2);
+ dshift = (int)(((final_width + 1) & 0x01) << 2);
s_start = 4;
s_end = 0;
s_inc = -4;
}
+
else
#endif
{
- sshift = (int)((1 - ((row_info->width + 1) & 1)) << 2);
- dshift = (int)((1 - ((final_width + 1) & 1)) << 2);
+ sshift = (int)((1 - ((row_info->width + 1) & 0x01)) << 2);
+ dshift = (int)((1 - ((final_width + 1) & 0x01)) << 2);
s_start = 0;
s_end = 4;
s_inc = 4;
}
- for (i = row_info->width; i; i--)
+ for (i = 0; i < row_info->width; i++)
{
- png_byte v;
+ png_byte v = (png_byte)((*sp >> sshift) & 0x0f);
int j;
- v = (png_byte)((*sp >> sshift) & 0xf);
- for (j = 0; j < png_pass_inc[pass]; j++)
+ 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)
{
dshift = s_start;
dp--;
}
+
else
dshift += s_inc;
}
+
if (sshift == s_end)
{
sshift = s_start;
sp--;
}
+
else
sshift += s_inc;
}
break;
}
+
default:
{
- png_bytep sp, dp;
- png_uint_32 i;
- png_size_t pixel_bytes;
+ png_size_t pixel_bytes = (row_info->pixel_depth >> 3);
- pixel_bytes = (row_info->pixel_depth >> 3);
+ png_bytep sp = row + (png_size_t)(row_info->width - 1)
+ * pixel_bytes;
- sp = row + (png_size_t)(row_info->width - 1) * pixel_bytes;
- dp = row + (png_size_t)(final_width - 1) * pixel_bytes;
- for (i = row_info->width; i; i--)
+ png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes;
+
+ int jstop = png_pass_inc[pass];
+ png_uint_32 i;
+
+ for (i = 0; i < row_info->width; i++)
{
png_byte v[8];
int j;
- png_memcpy(v, sp, pixel_bytes);
- for (j = 0; j < png_pass_inc[pass]; j++)
+ 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;
}
+
sp -= pixel_bytes;
}
break;
}
}
+
row_info->width = final_width;
- row_info->rowbytes = ((final_width *
- (png_uint_32)row_info->pixel_depth + 7) >> 3);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width);
+ }
+#ifndef PNG_READ_PACKSWAP_SUPPORTED
+ PNG_UNUSED(transformations) /* Silence compiler warning */
+#endif
+}
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
+
+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_structrp pp, png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row, int 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);
+}
-void
-png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
- png_bytep prev_row, int filter)
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+void /* PRIVATE */
+png_read_IDAT_data(png_structrp png_ptr, png_bytep output,
+ png_alloc_size_t avail_out)
{
- png_debug(1, "in png_read_filter_row\n");
- png_debug2(2,"row = %d, filter = %d\n", png_ptr->row_number, filter);
+ /* 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;
- switch (filter)
+ do
{
- case PNG_FILTER_VALUE_NONE:
- break;
- case PNG_FILTER_VALUE_SUB:
+ int ret;
+ png_byte tmpbuf[PNG_INFLATE_BUF_SIZE];
+
+ if (png_ptr->zstream.avail_in == 0)
{
- png_uint_32 i;
- int bpp;
- png_bytep rp;
- png_bytep lp;
-
- bpp = (row_info->pixel_depth + 7) / 8;
- for (i = (png_uint_32)bpp, rp = row + bpp, lp = row;
- i < row_info->rowbytes; i++, rp++, lp++)
+ uInt avail_in;
+ png_bytep buffer;
+
+ while (png_ptr->idat_size == 0)
{
- *rp = (png_byte)(((int)(*rp) + (int)(*lp)) & 0xff);
+ 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_uint_32 i;
- png_bytep rp;
- png_bytep pp;
+ uInt out = ZLIB_IO_MAX;
- for (i = 0, rp = row, pp = prev_row;
- i < row_info->rowbytes; i++, rp++, pp++)
- {
- *rp = (png_byte)(((int)(*rp) + (int)(*pp)) & 0xff);
- }
- 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_uint_32 i;
- int bpp;
- png_bytep rp;
- png_bytep pp;
- png_bytep lp;
-
- bpp = (row_info->pixel_depth + 7) / 8;
- for (i = 0, rp = row, pp = prev_row;
- i < (png_uint_32)bpp; i++, rp++, pp++)
- {
- *rp = (png_byte)(((int)(*rp) +
- ((int)(*pp) / 2)) & 0xff);
- }
- for (lp = row; i < row_info->rowbytes; i++, rp++, lp++, pp++)
- {
- *rp = (png_byte)(((int)(*rp) +
- (int)(*pp + *lp) / 2) & 0xff);
- }
+ png_ptr->zstream.next_out = tmpbuf;
+ png_ptr->zstream.avail_out = (sizeof tmpbuf);
+ }
+
+ /* 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);
+
+ /* Take the unconsumed output back. */
+ if (output != NULL)
+ avail_out += png_ptr->zstream.avail_out;
+
+ 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)
{
- int bpp;
- png_uint_32 i;
- png_bytep rp;
- png_bytep pp;
- png_bytep lp;
- png_bytep cp;
-
- bpp = (row_info->pixel_depth + 7) / 8;
- for (i = 0, rp = row, pp = prev_row,
- lp = row - bpp, cp = prev_row - bpp;
- i < row_info->rowbytes; i++, rp++, pp++, lp++, cp++)
- {
- int a, b, c, pa, pb, pc, p;
+ png_zstream_error(png_ptr, ret);
- b = *pp;
- if (i >= (png_uint_32)bpp)
- {
- c = *cp;
- a = *lp;
- }
- else
- {
- a = c = 0;
- }
- p = a + b - c;
- pa = abs(p - a);
- pb = abs(p - b);
- pc = abs(p - c);
-
- if (pa <= pb && pa <= pc)
- p = a;
- else if (pb <= pc)
- p = b;
- else
- p = c;
+ if (output != NULL)
+ png_chunk_error(png_ptr, png_ptr->zstream.msg);
- *rp = (png_byte)(((int)(*rp) + p) & 0xff);
+ else /* checking */
+ {
+ png_chunk_benign_error(png_ptr, png_ptr->zstream.msg);
+ return;
}
- break;
}
- default:
- png_error(png_ptr, "Bad adaptive filter type");
- break;
+ } while (avail_out > 0);
+
+ 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");
+
+ else /* the deflate stream contained extra data */
+ png_chunk_benign_error(png_ptr, "Too much image data");
+ }
+}
+
+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 */
+
+ /* 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;
+ }
+ }
+
+ /* 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;
+
+ /* Now we no longer own the zstream. */
+ png_ptr->zowner = 0;
+
+ /* 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);
}
}
-void
-png_read_finish_row(png_structp png_ptr)
+void /* PRIVATE */
+png_read_finish_row(png_structrp png_ptr)
{
- png_debug(1, "in png_read_finish_row\n");
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+ /* Start of interlace block */
+ static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+ /* Offset to next interlace block */
+ static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+ /* Start of interlace block in the y direction */
+ static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+
+ /* Offset to next interlace block in the y direction */
+ static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
+
+ png_debug(1, "in png_read_finish_row");
png_ptr->row_number++;
if (png_ptr->row_number < png_ptr->num_rows)
return;
+#ifdef PNG_READ_INTERLACING_SUPPORTED
if (png_ptr->interlaced)
{
png_ptr->row_number = 0;
- png_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+
+ /* TO DO: don't do this if prev_row isn't needed (requires
+ * read-ahead of the next row's filter byte.
+ */
+ memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+
do
{
png_ptr->pass++;
+
if (png_ptr->pass >= 7)
break;
+
png_ptr->iwidth = (png_ptr->width +
png_pass_inc[png_ptr->pass] - 1 -
png_pass_start[png_ptr->pass]) /
png_pass_inc[png_ptr->pass];
- png_ptr->irowbytes = ((png_ptr->iwidth *
- (png_uint_32)png_ptr->pixel_depth + 7) >> 3) +1;
if (!(png_ptr->transformations & PNG_INTERLACE))
{
png_ptr->num_rows = (png_ptr->height +
- png_pass_yinc[png_ptr->pass] - 1 -
- png_pass_ystart[png_ptr->pass]) /
- png_pass_yinc[png_ptr->pass];
- if (!(png_ptr->num_rows))
- continue;
+ png_pass_yinc[png_ptr->pass] - 1 -
+ png_pass_ystart[png_ptr->pass]) /
+ png_pass_yinc[png_ptr->pass];
}
- if (png_ptr->transformations & PNG_INTERLACE)
- break;
- } while (png_ptr->iwidth == 0);
+
+ else /* if (png_ptr->transformations & PNG_INTERLACE) */
+ break; /* libpng deinterlacing sees every row */
+
+ } while (png_ptr->num_rows == 0 || png_ptr->iwidth == 0);
if (png_ptr->pass < 7)
return;
}
+#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_byte chunk_length[4];
-
- png_crc_finish(png_ptr, 0);
-
- png_read_data(png_ptr, chunk_length, 4);
- png_ptr->idat_size = png_get_uint_32(chunk_length);
-
- png_reset_crc(png_ptr);
- png_crc_read(png_ptr, png_ptr->chunk_name, 4);
- if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
- 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_error(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");
+ /* Here after at the end of the last row of the last pass. */
+ png_read_finish_IDAT(png_ptr);
+}
+#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
- if (!(png_ptr->zstream.avail_out))
- png_error(png_ptr, "Extra compressed data");
+void /* PRIVATE */
+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_ptr->zstream.avail_out = 0;
- }
+ /* Start of interlace block */
+ static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
- if (png_ptr->idat_size || png_ptr->zstream.avail_in)
- png_error(png_ptr, "Extra compression data");
+ /* Offset to next interlace block */
+ static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
- inflateReset(&png_ptr->zstream);
+ /* Start of interlace block in the y direction */
+ static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
- png_ptr->mode |= PNG_AFTER_IDAT;
-}
+ /* Offset to next interlace block in the y direction */
+ static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+#endif
-void
-png_read_start_row(png_structp png_ptr)
-{
int max_pixel_depth;
- png_uint_32 rowbytes;
+ png_size_t row_bytes;
- png_debug(1, "in png_read_start_row\n");
- png_ptr->zstream.avail_in = 0;
+ png_debug(1, "in png_read_start_row");
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
png_init_read_transformations(png_ptr);
+#endif
+#ifdef PNG_READ_INTERLACING_SUPPORTED
if (png_ptr->interlaced)
{
if (!(png_ptr->transformations & PNG_INTERLACE))
png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
- png_pass_ystart[0]) / png_pass_yinc[0];
+ png_pass_ystart[0]) / png_pass_yinc[0];
+
else
png_ptr->num_rows = png_ptr->height;
png_ptr->iwidth = (png_ptr->width +
- png_pass_inc[png_ptr->pass] - 1 -
- png_pass_start[png_ptr->pass]) /
- png_pass_inc[png_ptr->pass];
-
- rowbytes = ((png_ptr->iwidth *
- (png_uint_32)png_ptr->pixel_depth + 7) >> 3) +1;
- png_ptr->irowbytes = (png_size_t)rowbytes;
- if((png_uint_32)png_ptr->irowbytes != rowbytes)
- png_error(png_ptr, "Rowbytes overflow in png_read_start_row");
+ png_pass_inc[png_ptr->pass] - 1 -
+ png_pass_start[png_ptr->pass]) /
+ png_pass_inc[png_ptr->pass];
}
+
else
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
{
png_ptr->num_rows = png_ptr->height;
png_ptr->iwidth = png_ptr->width;
- png_ptr->irowbytes = png_ptr->rowbytes + 1;
}
+
max_pixel_depth = png_ptr->pixel_depth;
-#if defined(PNG_READ_PACK_SUPPORTED)
+ /* 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;
#endif
-#if defined(PNG_READ_EXPAND_SUPPORTED)
+#ifdef PNG_READ_EXPAND_SUPPORTED
if (png_ptr->transformations & PNG_EXPAND)
{
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
{
if (png_ptr->num_trans)
max_pixel_depth = 32;
+
else
max_pixel_depth = 24;
}
+
else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
{
if (max_pixel_depth < 8)
max_pixel_depth = 8;
+
if (png_ptr->num_trans)
max_pixel_depth *= 2;
}
+
else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
{
if (png_ptr->num_trans)
}
#endif
-#if defined(PNG_READ_FILLER_SUPPORTED)
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+ if (png_ptr->transformations & PNG_EXPAND_16)
+ {
+# ifdef PNG_READ_EXPAND_SUPPORTED
+ /* In fact it is an error if it isn't supported, but checking is
+ * the safe way.
+ */
+ if (png_ptr->transformations & PNG_EXPAND)
+ {
+ if (png_ptr->bit_depth < 16)
+ max_pixel_depth *= 2;
+ }
+ else
+# endif
+ png_ptr->transformations &= ~PNG_EXPAND_16;
+ }
+#endif
+
+#ifdef PNG_READ_FILLER_SUPPORTED
if (png_ptr->transformations & (PNG_FILLER))
{
- if (max_pixel_depth < 32)
- max_pixel_depth = 32;
+ if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ if (max_pixel_depth <= 8)
+ max_pixel_depth = 16;
+
+ else
+ max_pixel_depth = 32;
+ }
+
+ 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;
+
+ else
+ max_pixel_depth = 64;
+ }
}
#endif
-#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
if (png_ptr->transformations & PNG_GRAY_TO_RGB)
{
- if ((png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) ||
- png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ if (
+#ifdef PNG_READ_EXPAND_SUPPORTED
+ (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) ||
+#endif
+#ifdef PNG_READ_FILLER_SUPPORTED
+ (png_ptr->transformations & (PNG_FILLER)) ||
+#endif
+ png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
{
if (max_pixel_depth <= 16)
max_pixel_depth = 32;
- else if (max_pixel_depth <= 32)
+
+ else
max_pixel_depth = 64;
}
+
else
{
if (max_pixel_depth <= 8)
- max_pixel_depth = 24;
- else if (max_pixel_depth <= 16)
+ {
+ if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ max_pixel_depth = 32;
+
+ else
+ max_pixel_depth = 24;
+ }
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ max_pixel_depth = 64;
+
+ else
max_pixel_depth = 48;
}
}
#endif
- /* align the width on the next larger 8 pixels. Mainly used
- for interlacing */
- rowbytes = ((png_ptr->width + 7) & ~((png_uint_32)7));
- /* calculate the maximum bytes needed, adding a byte and a pixel
- for safety sake */
- rowbytes = ((rowbytes * (png_uint_32)max_pixel_depth + 7) >> 3) +
- 1 + ((max_pixel_depth + 7) >> 3);
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \
+defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
+ if (png_ptr->transformations & PNG_USER_TRANSFORM)
+ {
+ int user_pixel_depth = png_ptr->user_transform_depth *
+ png_ptr->user_transform_channels;
+
+ if (user_pixel_depth > max_pixel_depth)
+ max_pixel_depth = user_pixel_depth;
+ }
+#endif
+
+ /* This value is stored in png_struct and double checked in the row read
+ * code.
+ */
+ png_ptr->maximum_pixel_depth = (png_byte)max_pixel_depth;
+ png_ptr->transformed_pixel_depth = 0; /* calculated on demand */
+
+ /* Align the width on the next larger 8 pixels. Mainly used
+ * for interlacing
+ */
+ row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7));
+ /* Calculate the maximum bytes needed, adding a byte and a pixel
+ * for safety's sake
+ */
+ row_bytes = PNG_ROWBYTES(max_pixel_depth, row_bytes) +
+ 1 + ((max_pixel_depth + 7) >> 3);
+
#ifdef PNG_MAX_MALLOC_64K
- if (rowbytes > (png_uint_32)65536L)
+ if (row_bytes > (png_uint_32)65536L)
png_error(png_ptr, "This image requires a row greater than 64KB");
#endif
- png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, rowbytes);
+
+ if (row_bytes + 48 > png_ptr->old_big_row_buf_size)
+ {
+ png_free(png_ptr, png_ptr->big_row_buf);
+ png_free(png_ptr, png_ptr->big_prev_row);
+
+ if (png_ptr->interlaced)
+ png_ptr->big_row_buf = (png_bytep)png_calloc(png_ptr,
+ row_bytes + 48);
+
+ else
+ png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes + 48);
+
+ png_ptr->big_prev_row = (png_bytep)png_malloc(png_ptr, row_bytes + 48);
+
+#ifdef PNG_ALIGNED_MEMORY_SUPPORTED
+ /* Use 16-byte aligned memory for row_buf with at least 16 bytes
+ * of padding before and after row_buf; treat prev_row similarly.
+ * NOTE: the alignment is to the start of the pixels, one beyond the start
+ * of the buffer, because of the filter byte. Prior to libpng 1.5.6 this
+ * was incorrect; the filter byte was aligned, which had the exact
+ * opposite effect of that intended.
+ */
+ {
+ png_bytep temp = png_ptr->big_row_buf + 32;
+ int extra = (int)((temp - (png_bytep)0) & 0x0f);
+ png_ptr->row_buf = temp - extra - 1/*filter byte*/;
+
+ temp = png_ptr->big_prev_row + 32;
+ extra = (int)((temp - (png_bytep)0) & 0x0f);
+ png_ptr->prev_row = temp - extra - 1/*filter byte*/;
+ }
+
+#else
+ /* Use 31 bytes of padding before and 17 bytes after row_buf. */
+ png_ptr->row_buf = png_ptr->big_row_buf + 31;
+ png_ptr->prev_row = png_ptr->big_prev_row + 31;
+#endif
+ png_ptr->old_big_row_buf_size = row_bytes + 48;
+ }
#ifdef PNG_MAX_MALLOC_64K
- if ((png_uint_32)png_ptr->rowbytes + 1 > (png_uint_32)65536L)
+ if (png_ptr->rowbytes > 65535)
png_error(png_ptr, "This image requires a row greater than 64KB");
+
#endif
- png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)(
- png_ptr->rowbytes + 1));
+ if (png_ptr->rowbytes > (PNG_SIZE_MAX - 1))
+ png_error(png_ptr, "Row has too many bytes to allocate in memory");
+
+ 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, "iwidth = %u,", png_ptr->iwidth);
+ png_debug1(3, "num_rows = %u,", png_ptr->num_rows);
+ png_debug1(3, "rowbytes = %lu,", (unsigned long)png_ptr->rowbytes);
+ 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_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+ png_ptr->read_buffer_size = 0;
+ png_ptr->read_buffer = NULL;
+ png_free(png_ptr, buffer);
+ }
- png_debug1(3, "width = %d,\n", png_ptr->width);
- png_debug1(3, "height = %d,\n", png_ptr->height);
- png_debug1(3, "iwidth = %d,\n", png_ptr->iwidth);
- png_debug1(3, "num_rows = %d\n", png_ptr->num_rows);
- png_debug1(3, "rowbytes = %d,\n", png_ptr->rowbytes);
- png_debug1(3, "irowbytes = %d,\n", png_ptr->irowbytes);
+ /* 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