int ff_rtmp_calc_digest(const uint8_t *src, int len, int gap, const uint8_t *key, int keylen, uint8_t *dst)
Calculate HMAC-SHA2 digest for RTMP handshake packets.
int ff_rtmp_calc_digest_pos(const uint8_t *buf, int off, int mod_val, int add_val)
Calculate digest position for RTMP handshake packets.