api! Remove the experimental (and incomplete) ERROR_NUMBERS code

The purpose of this feature is to optionally prepend standardized
numbers to error and warning messages. The ERROR_NUMBERS feature was
first drafted in libpng-1.2.0 and further developed in libpng-1.4.0;
and yet, it was always disabled by default, and never completed.

In the light of a recent report concerning the security hazards arising
from enabling this code in custom libpng builds, we think it's best to
simply remove all the code written to support this feature.

Based on removal in libpng18, but keeping functions and options as
no-ops for backwards compatibility.

Co-authored-by: Cosmin Truta <ctruta@gmail.com>
This commit is contained in:
Tobias Stoeckmann
2025-09-29 22:10:27 +02:00
co-authored by Cosmin Truta
parent c6913e22df
commit bd41aa64d3
4 changed files with 8 additions and 139 deletions
-4
View File
@@ -244,10 +244,6 @@ png_user_version_check(png_structrp png_ptr, png_const_charp user_png_ver)
png_warning(png_ptr, m);
#endif
#ifdef PNG_ERROR_NUMBERS_SUPPORTED
png_ptr->flags = 0;
#endif
return 0;
}
-3
View File
@@ -38,9 +38,6 @@
#define PNGDEBUG_H
/* These settings control the formatting of messages in png.c and pngerror.c */
/* Moved to pngdebug.h at 1.5.0 */
# ifndef PNG_LITERAL_SHARP
# define PNG_LITERAL_SHARP 0x23
# endif
# ifndef PNG_LITERAL_LEFT_SQUARE_BRACKET
# define PNG_LITERAL_LEFT_SQUARE_BRACKET 0x5b
# endif
+7 -131
View File
@@ -39,46 +39,6 @@ PNG_FUNCTION(void,PNGAPI
png_error,(png_const_structrp png_ptr, png_const_charp error_message),
PNG_NORETURN)
{
#ifdef PNG_ERROR_NUMBERS_SUPPORTED
char msg[16];
if (png_ptr != NULL)
{
if ((png_ptr->flags &
(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0)
{
if (*error_message == PNG_LITERAL_SHARP)
{
/* Strip "#nnnn " from beginning of error message. */
int offset;
for (offset = 1; offset<15; offset++)
if (error_message[offset] == ' ')
break;
if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0)
{
int i;
for (i = 0; i < offset - 1; i++)
msg[i] = error_message[i + 1];
msg[i - 1] = '\0';
error_message = msg;
}
else
error_message += offset;
}
else
{
if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0)
{
msg[0] = '0';
msg[1] = '\0';
error_message = msg;
}
}
}
}
#endif
if (png_ptr != NULL && png_ptr->error_fn != NULL)
(*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr),
error_message);
@@ -216,21 +176,6 @@ void PNGAPI
png_warning(png_const_structrp png_ptr, png_const_charp warning_message)
{
int offset = 0;
if (png_ptr != NULL)
{
#ifdef PNG_ERROR_NUMBERS_SUPPORTED
if ((png_ptr->flags &
(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0)
#endif
{
if (*warning_message == PNG_LITERAL_SHARP)
{
for (offset = 1; offset < 15; offset++)
if (warning_message[offset] == ' ')
break;
}
}
}
if (png_ptr != NULL && png_ptr->warning_fn != NULL)
(*(png_ptr->warning_fn))(png_constcast(png_structrp,png_ptr),
warning_message + offset);
@@ -712,42 +657,9 @@ png_default_error,(png_const_structrp png_ptr, png_const_charp error_message),
PNG_NORETURN)
{
#ifdef PNG_CONSOLE_IO_SUPPORTED
#ifdef PNG_ERROR_NUMBERS_SUPPORTED
/* Check on NULL only added in 1.5.4 */
if (error_message != NULL && *error_message == PNG_LITERAL_SHARP)
{
/* Strip "#nnnn " from beginning of error message. */
int offset;
char error_number[16];
for (offset = 0; offset<15; offset++)
{
error_number[offset] = error_message[offset + 1];
if (error_message[offset] == ' ')
break;
}
if ((offset > 1) && (offset < 15))
{
error_number[offset - 1] = '\0';
fprintf(stderr, "libpng error no. %s: %s",
error_number, error_message + offset + 1);
fprintf(stderr, PNG_STRING_NEWLINE);
}
else
{
fprintf(stderr, "libpng error: %s, offset=%d",
error_message, offset);
fprintf(stderr, PNG_STRING_NEWLINE);
}
}
else
#endif
{
fprintf(stderr, "libpng error: %s", error_message ? error_message :
"undefined");
fprintf(stderr, PNG_STRING_NEWLINE);
}
fprintf(stderr, "libpng error: %s", error_message ? error_message :
"undefined");
fprintf(stderr, PNG_STRING_NEWLINE);
#else
PNG_UNUSED(error_message) /* Make compiler happy */
#endif
@@ -785,40 +697,8 @@ static void /* PRIVATE */
png_default_warning(png_const_structrp png_ptr, png_const_charp warning_message)
{
#ifdef PNG_CONSOLE_IO_SUPPORTED
# ifdef PNG_ERROR_NUMBERS_SUPPORTED
if (*warning_message == PNG_LITERAL_SHARP)
{
int offset;
char warning_number[16];
for (offset = 0; offset < 15; offset++)
{
warning_number[offset] = warning_message[offset + 1];
if (warning_message[offset] == ' ')
break;
}
if ((offset > 1) && (offset < 15))
{
warning_number[offset + 1] = '\0';
fprintf(stderr, "libpng warning no. %s: %s",
warning_number, warning_message + offset);
fprintf(stderr, PNG_STRING_NEWLINE);
}
else
{
fprintf(stderr, "libpng warning: %s",
warning_message);
fprintf(stderr, PNG_STRING_NEWLINE);
}
}
else
# endif
{
fprintf(stderr, "libpng warning: %s", warning_message);
fprintf(stderr, PNG_STRING_NEWLINE);
}
fprintf(stderr, "libpng warning: %s", warning_message);
fprintf(stderr, PNG_STRING_NEWLINE);
#else
PNG_UNUSED(warning_message) /* Make compiler happy */
#endif
@@ -866,12 +746,8 @@ png_get_error_ptr(png_const_structrp png_ptr)
void PNGAPI
png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode)
{
if (png_ptr != NULL)
{
png_ptr->flags &=
((~(PNG_FLAG_STRIP_ERROR_NUMBERS |
PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
}
PNG_UNUSED(png_ptr)
PNG_UNUSED(strip_mode)
}
#endif
+1 -1
View File
@@ -712,7 +712,7 @@
/* #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000U */
/* #define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000U */
#define PNG_FLAG_LIBRARY_MISMATCH 0x20000U
#define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000U
/* 0x40000U unused */
#define PNG_FLAG_STRIP_ERROR_TEXT 0x80000U
#define PNG_FLAG_BENIGN_ERRORS_WARN 0x100000U /* Added to libpng-1.4.0 */
#define PNG_FLAG_APP_WARNINGS_WARN 0x200000U /* Added to libpng-1.6.0 */