From 4fee11ab05fc8569ef35c0ce86a60375c903eefb Mon Sep 17 00:00:00 2001 From: Luca Barbato Date: Fri, 31 Jul 2015 14:24:08 +0200 Subject: png: Be more informative regarding signature errors Signed-off-by: Luca Barbato --- libavcodec/pngdec.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) (limited to 'libavcodec/pngdec.c') diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c index 4ca919bd89..5fa7a2dfdf 100644 --- a/libavcodec/pngdec.c +++ b/libavcodec/pngdec.c @@ -18,6 +18,8 @@ * License along with Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ + +#include "libavutil/avstring.h" #include "libavutil/imgutils.h" #include "avcodec.h" #include "bytestream.h" @@ -414,9 +416,21 @@ static int decode_frame(AVCodecContext *avctx, int ret; /* check signature */ - if (buf_size < 8 || - (memcmp(buf, ff_pngsig, 8) != 0 && memcmp(buf, ff_mngsig, 8) != 0)) { - av_log(avctx, AV_LOG_ERROR, "Invalid PNG signature (%d).\n", buf_size); + if (buf_size < 8) { + av_log(avctx, AV_LOG_ERROR, "Not enough data %d\n", + buf_size); + return AVERROR_INVALIDDATA; + } + if (memcmp(buf, ff_pngsig, 8) != 0 && + memcmp(buf, ff_mngsig, 8) != 0) { + char signature[5 * 8 + 1] = { 0 }; + int i; + for (i = 0; i < 8; i++) { + av_strlcatf(signature + i * 5, sizeof(signature) - i * 5, + " 0x%02x", buf[i]); + } + av_log(avctx, AV_LOG_ERROR, "Invalid PNG signature %s\n", + signature); return AVERROR_INVALIDDATA; } -- cgit v1.2.3