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/*
* Copyright (c) 2001-2002 Michael David Adams.
* All rights reserved.
*/
/* __START_OF_JASPER_LICENSE__
*
* JasPer License Version 2.0
*
* Copyright (c) 2001-2006 Michael David Adams
* Copyright (c) 1999-2000 Image Power, Inc.
* Copyright (c) 1999-2000 The University of British Columbia
*
* All rights reserved.
*
* Permission is hereby granted, free of charge, to any person (the
* "User") obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge,
* publish, distribute, and/or sell copies of the Software, and to permit
* persons to whom the Software is furnished to do so, subject to the
* following conditions:
*
* 1. The above copyright notices and this permission notice (which
* includes the disclaimer below) shall be included in all copies or
* substantial portions of the Software.
*
* 2. The name of a copyright holder shall not be used to endorse or
* promote products derived from the Software without specific prior
* written permission.
*
* THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS
* LICENSE. NO USE OF THE SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER
* THIS DISCLAIMER. THE SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS
* "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
* BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
* PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. IN NO
* EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL
* INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING
* FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. NO ASSURANCES ARE
* PROVIDED BY THE COPYRIGHT HOLDERS THAT THE SOFTWARE DOES NOT INFRINGE
* THE PATENT OR OTHER INTELLECTUAL PROPERTY RIGHTS OF ANY OTHER ENTITY.
* EACH COPYRIGHT HOLDER DISCLAIMS ANY LIABILITY TO THE USER FOR CLAIMS
* BROUGHT BY ANY OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL
* PROPERTY RIGHTS OR OTHERWISE. AS A CONDITION TO EXERCISING THE RIGHTS
* GRANTED HEREUNDER, EACH USER HEREBY ASSUMES SOLE RESPONSIBILITY TO SECURE
* ANY OTHER INTELLECTUAL PROPERTY RIGHTS NEEDED, IF ANY. THE SOFTWARE
* IS NOT FAULT-TOLERANT AND IS NOT INTENDED FOR USE IN MISSION-CRITICAL
* SYSTEMS, SUCH AS THOSE USED IN THE OPERATION OF NUCLEAR FACILITIES,
* AIRCRAFT NAVIGATION OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL
* SYSTEMS, DIRECT LIFE SUPPORT MACHINES, OR WEAPONS SYSTEMS, IN WHICH
* THE FAILURE OF THE SOFTWARE OR SYSTEM COULD LEAD DIRECTLY TO DEATH,
* PERSONAL INJURY, OR SEVERE PHYSICAL OR ENVIRONMENTAL DAMAGE ("HIGH
* RISK ACTIVITIES"). THE COPYRIGHT HOLDERS SPECIFICALLY DISCLAIM ANY
* EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR HIGH RISK ACTIVITIES.
*
* __END_OF_JASPER_LICENSE__
*/
/******************************************************************************\
* Includes.
\******************************************************************************/
#include <stdio.h>
#include <assert.h>
#include "jasper/jas_stream.h"
#include "jasper/jas_image.h"
#include "jpg_cod.h"
/******************************************************************************\
* Code for validate operation.
\******************************************************************************/
int jpg_validate(jas_stream_t *in)
{
uchar buf[JPG_MAGICLEN];
int i;
int n;
assert(JAS_STREAM_MAXPUTBACK >= JPG_MAGICLEN);
/* Read the validation data (i.e., the data used for detecting
the format). */
if ((n = jas_stream_read(in, buf, JPG_MAGICLEN)) < 0) {
return -1;
}
/* Put the validation data back onto the stream, so that the
stream position will not be changed. */
for (i = n - 1; i >= 0; --i) {
if (jas_stream_ungetc(in, buf[i]) == EOF) {
return -1;
}
}
/* Did we read enough data? */
if (n < JPG_MAGICLEN) {
return -1;
}
/* Does this look like JPEG? */
if (buf[0] != (JPG_MAGIC >> 8) || buf[1] != (JPG_MAGIC & 0xff)) {
return -1;
}
return 0;
}
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