static vod_status_t
mp4_decrypt_start_frame(void* ctx, input_frame_t* frame)
{
mp4_decrypt_state_t* state = ctx;
vod_status_t rc;
rc = state->frames_source->start_frame(state->frames_source_context, frame);
if (rc != VOD_OK)
{
return rc;
}
// get the iv
if (state->auxiliary_info_pos + MP4_AES_CTR_IV_SIZE > state->auxiliary_info_end)
{
vod_log_error(VOD_LOG_ERR, state->request_context->log, 0,
"mp4_decrypt_start_frame: failed to get iv from auxiliary info");
return VOD_BAD_DATA;
}
mp4_aes_ctr_set_iv(&state->cipher, state->auxiliary_info_pos);
state->auxiliary_info_pos += MP4_AES_CTR_IV_SIZE;
if (!state->use_subsamples)
{
state->encrypted_bytes = UINT_MAX;
return VOD_OK;
}
// get the subsample info
if (state->auxiliary_info_pos + sizeof(uint16_t) + sizeof(cenc_sample_auxiliary_data_subsample_t) > state->auxiliary_info_end)
{
vod_log_error(VOD_LOG_ERR, state->request_context->log, 0,
"mp4_decrypt_start_frame: failed to get subsample info from auxiliary info");
return VOD_BAD_DATA;
}
read_be16(state->auxiliary_info_pos, state->subsample_count);
if (state->subsample_count <= 0)
{
vod_log_error(VOD_LOG_ERR, state->request_context->log, 0,
"mp4_decrypt_start_frame: invalid subsample count");
return VOD_BAD_DATA;
}
read_be16(state->auxiliary_info_pos, state->clear_bytes);
read_be32(state->auxiliary_info_pos, state->encrypted_bytes);
state->subsample_count--;
return VOD_OK;
}
static vod_status_t
mp4_encrypt_start_frame(mp4_encrypt_state_t* state)
{
// make sure we have a frame
if (state->cur_frame >= state->last_frame)
{
vod_log_error(VOD_LOG_ERR, state->request_context->log, 0,
"mp4_encrypt_start_frame: no more frames");
return VOD_BAD_DATA;
}
// get the frame size
state->frame_size_left = state->cur_frame->size;
state->cur_frame++;
// set and increment the iv
mp4_aes_ctr_set_iv(&state->cipher, state->iv);
mp4_aes_ctr_increment_be64(state->iv);
return VOD_OK;
}
