Mp4: added and updated sanity checks for "end" handling. When handling incorrect data in ngx_http_mp4_crop_stsc_data(), trak->end_chunk_samples might end up being arbitrary large, leading to reading before the buffer in ngx_http_mp4_update_stsz_atom(). Fix is to check that trak->end_chunk_samples corresponds to a memory within the stsz atom data. For consistency, trak->start_chunk_samples is checked similarly. Similarly, trak->end_chunk might end up being smaller than trak->start_chunk, leading to reading memory after the buffer in ngx_http_mp4_update_stco_atom() and ngx_http_mp4_update_co64_atom(). Corresponding checks are updated to explicitly test (trak->end_chunk - trak->start_chunk) instead of just checking trak->end_chunk and assuming it is larger than trak->start_chunk. This is generally in line with existing checks of (trak->end_sample - trak->start_sample) in ngx_http_mp4_update_stsz_atom(), where trak->end_sample might also become smaller than trak->start_sample when handling incorrect data in ngx_http_mp4_crop_stts_data().

/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_MD5_H_INCLUDED_
#define _NGX_MD5_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>


typedef struct {
    uint64_t  bytes;
    uint32_t  a, b, c, d;
    u_char    buffer[64];
} ngx_md5_t;


void ngx_md5_init(ngx_md5_t *ctx);
void ngx_md5_update(ngx_md5_t *ctx, const void *data, size_t size);
void ngx_md5_final(u_char result[16], ngx_md5_t *ctx);


#endif /* _NGX_MD5_H_INCLUDED_ */