[libpng17] Warn about ADLER32 checksum mismatch instead of issuing png_error().

Add tests/badcrc.png and tests/badadler.png to tests/pngtest.

ANNOUNCE

@@ -1,5 +1,5 @@
 
-Libpng 1.7.0beta84 - September 19, 2016
+Libpng 1.7.0beta84 - September 26, 2016
 
 This is not intended to be a public release.  It will be replaced
 within a few weeks by a public version or by another test version.
@@ -1396,13 +1396,17 @@ Version 1.7.0beta83 [July 23, 2016]
     in reading.
   Fixed debug test of output gamma.
 
-Version 1.7.0beta84 [September 19, 2016]
+Version 1.7.0beta84 [September 26, 2016]
   Minor editing of INSTALL, (whitespace, added copyright line)
   Don't install pngcp; it conflicts with pngcp in the pngtools package.
   Fixed handling zero length IDAT in pngfix (bug report by Agostino Sarubbo,
     bugfix by John Bowler).
   Conditionally compile png_set_benign_errors() in pngread.c and pngtest.c
   Changed PNG_ZLIB_VERNUM to ZLIB_VERNUM in pngrutil.c.
+  If CRC handling of critical chunks has been set to PNG_CRC_QUIET_USE,
+    ignore the ADLER32 checksum in the IDAT chunk as well as the chunk CRCs.
+  Warn about ADLER32 checksum mismatch instead of issuing a png_error().
+  Add tests/badcrc.png and tests/badadler.png to tests/pngtest.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

CHANGES

@@ -5696,13 +5696,17 @@ Version 1.7.0beta83 [July 23, 2016]
     in reading.
   Fixed debug test of output gamma.
 
-Version 1.7.0beta84 [September 19, 2016]
+Version 1.7.0beta84 [September 26, 2016]
   Minor editing of INSTALL, (whitespace, added copyright line)
   Don't install pngcp; it conflicts with pngcp in the pngtools package.
   Fixed handling zero length IDAT in pngfix (bug report by Agostino Sarubbo,
     bugfix by John Bowler).
   Conditionally compile png_set_benign_errors() in pngread.c and pngtest.c
   Changed PNG_ZLIB_VERNUM to ZLIB_VERNUM in pngrutil.c.
+  If CRC handling of critical chunks has been set to PNG_CRC_QUIET_USE,
+    ignore the ADLER32 checksum in the IDAT chunk as well as the chunk CRCs.
+  Warn about ADLER32 checksum mismatch instead of issuing a png_error().
+  Add tests/badcrc.png and tests/badadler.png to tests/pngtest.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

pngrutil.c

@@ -260,12 +260,12 @@ png_inflate_claim(png_structrp png_ptr, png_uint_32 owner)
        * are minimal.
        */
       (void)png_safecat(msg, (sizeof msg), 4, " using zstream");
-#     if PNG_RELEASE_BUILD
+#if PNG_RELEASE_BUILD
-         png_chunk_warning(png_ptr, msg);
+      png_chunk_warning(png_ptr, msg);
-         png_ptr->zowner = 0;
+      png_ptr->zowner = 0;
-#     else
+#else
-         png_chunk_error(png_ptr, msg);
+      png_chunk_error(png_ptr, msg);
-#     endif
+#endif
    }
 
    /* Implementation note: unlike 'png_deflate_claim' this internal function
@@ -283,21 +283,17 @@ png_inflate_claim(png_structrp png_ptr, png_uint_32 owner)
     */
    {
       int ret; /* zlib return code */
-#     if ZLIB_VERNUM >= 0x1240
+#if ZLIB_VERNUM >= 0x1240
+      int window_bits = 0;
 
-#        if defined(PNG_SET_OPTION_SUPPORTED) && \
+# if defined(PNG_SET_OPTION_SUPPORTED) && \
-            defined(PNG_MAXIMUM_INFLATE_WINDOW)
+  defined(PNG_MAXIMUM_INFLATE_WINDOW)
-            int window_bits;
 
             if (png_ptr->maximum_inflate_window)
                window_bits = 15;
 
-            else
+# endif
-               window_bits = 0;
+#endif /* ZLIB_VERNUM >= 0x1240 */
-#        else
-#           define window_bits 0
-#        endif
-#     endif
 
       /* Initialize the alloc/free callbacks every time: */
       png_ptr->zstream.zalloc = png_zalloc;
@@ -317,22 +313,28 @@ png_inflate_claim(png_structrp png_ptr, png_uint_32 owner)
        */
       if (png_ptr->zstream.state != NULL)
       {
-#        if ZLIB_VERNUM < 0x1240
+#if ZLIB_VERNUM >= 0x1240
-            ret = inflateReset(&png_ptr->zstream);
+         ret = inflateReset2(&png_ptr->zstream, window_bits);
-#        else
+#else
-            ret = inflateReset2(&png_ptr->zstream, window_bits);
+         ret = inflateReset(&png_ptr->zstream);
-#        endif
+#endif
       }
 
       else
       {
-#        if ZLIB_VERNUM < 0x1240
+#if ZLIB_VERNUM >= 0x1240
-            ret = inflateInit(&png_ptr->zstream);
+         ret = inflateInit2(&png_ptr->zstream, window_bits);
-#        else
+#else
-            ret = inflateInit2(&png_ptr->zstream, window_bits);
+         ret = inflateInit(&png_ptr->zstream);
-#        endif
+#endif
       }
 
+#if ZLIB_VERNUM >= 0x1240
+      /* Turn off validation of the ADLER32 checksum */
+      if (png_ptr->current_crc == crc_quiet_use)
+         ret = inflateReset2(&png_ptr->zstream, -window_bits);
+#endif
+
       if (ret == Z_OK && png_ptr->zstream.state != NULL)
       {
          png_ptr->zowner = owner;
@@ -3770,24 +3772,38 @@ png_inflate_IDAT(png_structrp png_ptr, int finish,
     */
    if (!png_ptr->zstream_error) /* first time */
    {
-#     ifdef PNG_BENIGN_READ_ERRORS_SUPPORTED
+#ifdef PNG_BENIGN_READ_ERRORS_SUPPORTED
-         switch (png_ptr->IDAT_error_action)
+      switch (png_ptr->IDAT_error_action)
-         {
+      {
-            case PNG_ERROR:
+         case PNG_ERROR:
+            if(!strncmp(png_ptr->zstream.msg,"incorrect data check",20))
+            {
+               if (png_ptr->current_crc != crc_quiet_use)
+                  png_chunk_warning(png_ptr, "ADLER32 checksum mismatch");
+            }
+
+            else
+            {
                png_chunk_error(png_ptr, png_ptr->zstream.msg);
-               break;
+            }
+            break;
 
-            case PNG_WARN:
+         case PNG_WARN:
-               png_chunk_warning(png_ptr, png_ptr->zstream.msg);
+            png_chunk_warning(png_ptr, png_ptr->zstream.msg);
-               break;
+            break;
 
-            default: /* ignore */
+         default: /* ignore */
-               /* Keep going */
+            /* Keep going */
-               break;
+            break;
-         }
+      }
-#     else
+#else
-         png_chunk_error(png_ptr, png_ptr->zstream.msg);
+      {
-#     endif /* !BENIGN_ERRORS */
+         if(!strncmp(png_ptr->zstream.msg,"incorrect data check",20))
+            png_chunk_warning(png_ptr, "ADLER32 checksum mismatch");
+         else
+            png_chunk_error(png_ptr, png_ptr->zstream.msg);
+      }
+#endif /* !BENIGN_ERRORS */
 
       /* And prevent the report about too many IDATs on streams with internal
        * LZ errors:

pngtest.c

@@ -986,9 +986,13 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       /* Allow application (pngtest) errors and warnings to pass */
       png_set_benign_errors(read_ptr, 1);
 
+      /* Turn off CRC and ADLER32 checking while reading */
+      png_set_crc_action(read_ptr, PNG_CRC_QUIET_USE, PNG_CRC_QUIET_USE);
+
 # ifdef PNG_WRITE_SUPPORTED
       png_set_benign_errors(write_ptr, 1);
 # endif
+
    }
 #endif /* BENIGN_ERRORS */
 

tests/pngtest

@@ -1,2 +1,4 @@
 #!/bin/sh
+./pngtest --relaxed ${srcdir}/tests/badcrc.png
+./pngtest --relaxed ${srcdir}/tests/badadler.png
 exec ./pngtest --strict ${srcdir}/pngtest.png