| /* |
| * RTMP network protocol |
| * Copyright (c) 2009 Konstantin Shishkov |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| /** |
| * @file |
| * RTMP protocol digest |
| */ |
| |
| #include <stdint.h> |
| |
| #include "libavutil/error.h" |
| #include "libavutil/hmac.h" |
| |
| #include "rtmp.h" |
| |
| int ff_rtmp_calc_digest(const uint8_t *src, int len, int gap, |
| const uint8_t *key, int keylen, uint8_t *dst) |
| { |
| AVHMAC *hmac; |
| |
| hmac = av_hmac_alloc(AV_HMAC_SHA256); |
| if (!hmac) |
| return AVERROR(ENOMEM); |
| |
| av_hmac_init(hmac, key, keylen); |
| if (gap <= 0) { |
| av_hmac_update(hmac, src, len); |
| } else { //skip 32 bytes used for storing digest |
| av_hmac_update(hmac, src, gap); |
| av_hmac_update(hmac, src + gap + 32, len - gap - 32); |
| } |
| av_hmac_final(hmac, dst, 32); |
| |
| av_hmac_free(hmac); |
| |
| return 0; |
| } |
| |
| int ff_rtmp_calc_digest_pos(const uint8_t *buf, int off, int mod_val, |
| int add_val) |
| { |
| int i, digest_pos = 0; |
| |
| for (i = 0; i < 4; i++) |
| digest_pos += buf[i + off]; |
| digest_pos = digest_pos % mod_val + add_val; |
| |
| return digest_pos; |
| } |