hls: add vod_hls_encryption_output_iv directive (#1514)

* hls: add vod_hls_encryption_output_iv variable

* remove complexity just return IV when vod_hls_encryption_output_iv is enabled

Author: nonth

README.md

@@ -1714,6 +1714,13 @@ The parameter value can contain variables.
 When enabled, the module will shift back the dts timestamps by the pts delay of the initial frame.
 This can help keep the pts timestamps aligned across multiple renditions.
 
+#### vod_hls_encryption_output_iv
+* **syntax**: `vod_hls_encryption_output_iv on/off`
+* **default**: `off`
+* **context**: `http`, `server`, `location`
+
+When enabled, the module outputs the `IV` attribute in returned `#EXT-X-KEY` tags.
+
 ### Configuration directives - MSS
 
 #### vod_mss_manifest_file_name_prefix

ngx_http_vod_hls.c

@@ -171,7 +171,7 @@ ngx_http_vod_hls_init_encryption_params(
 	}
 
 	encryption_params->iv = encryption_params->iv_buf;
-	encryption_params->return_iv = FALSE;
+	encryption_params->return_iv = conf->hls.output_iv;
 
 	sequence = &submodule_context->media_set.sequences[0];
 
@@ -1116,6 +1116,7 @@ ngx_http_vod_hls_create_loc_conf(
 	conf->align_pts = NGX_CONF_UNSET;
 	conf->output_id3_timestamps = NGX_CONF_UNSET;
 	conf->encryption_method = NGX_CONF_UNSET_UINT;
+	conf->output_iv = NGX_CONF_UNSET;
 	conf->m3u8_config.output_iframes_playlist = NGX_CONF_UNSET;
 	conf->m3u8_config.force_unmuxed_segments = NGX_CONF_UNSET;
 	conf->m3u8_config.container_format = NGX_CONF_UNSET_UINT;
@@ -1131,6 +1132,7 @@ ngx_http_vod_hls_merge_loc_conf(
 	ngx_conf_merge_value(conf->absolute_master_urls, prev->absolute_master_urls, 1);
 	ngx_conf_merge_value(conf->absolute_index_urls, prev->absolute_index_urls, 1);
 	ngx_conf_merge_value(conf->absolute_iframe_urls, prev->absolute_iframe_urls, 0);
+	ngx_conf_merge_value(conf->output_iv, prev->output_iv, 0);
 	ngx_conf_merge_value(conf->m3u8_config.output_iframes_playlist, prev->m3u8_config.output_iframes_playlist, 1);
 
 	ngx_conf_merge_str_value(conf->master_file_name_prefix, prev->master_file_name_prefix, "master");

ngx_http_vod_hls_commands.h

@@ -35,6 +35,13 @@
 	NGX_HTTP_LOC_CONF_OFFSET,
 	BASE_OFFSET + offsetof(ngx_http_vod_hls_loc_conf_t, m3u8_config.encryption_key_format_versions),
 	NULL },	
+
+	{ ngx_string("vod_hls_encryption_output_iv"),
+	NGX_HTTP_MAIN_CONF | NGX_HTTP_SRV_CONF | NGX_HTTP_LOC_CONF | NGX_CONF_TAKE1,
+	ngx_conf_set_flag_slot,
+	NGX_HTTP_LOC_CONF_OFFSET,
+	BASE_OFFSET + offsetof(ngx_http_vod_hls_loc_conf_t, output_iv),
+	NULL },
 #endif // NGX_HAVE_OPENSSL_EVP
 
 	{ ngx_string("vod_hls_container_format"),

ngx_http_vod_hls_conf.h

@@ -19,6 +19,7 @@ typedef struct
 	ngx_http_complex_value_t* id3_data;
 	vod_uint_t encryption_method;
 	ngx_http_complex_value_t* encryption_key_uri;
+	bool_t output_iv;
 
 	// derived fields
 	m3u8_config_t m3u8_config;