avformat/dashdec: Check whitelist

Fixes: CVE-2023-6602, V. DASH Playlist SSRF

Found-by: Harvey Phillips of Amazon Element55 (element55)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 4c96d6bf75)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/dashdec.c

@@ -446,7 +446,7 @@ static int open_url(AVFormatContext *s, AVIOContext **pb, const char *url,
     av_freep(pb);
     av_dict_copy(&tmp, *opts, 0);
     av_dict_copy(&tmp, opts2, 0);
-    ret = avio_open2(pb, url, AVIO_FLAG_READ, c->interrupt_callback, &tmp);
+    ret = ffio_open_whitelist(pb, url, AVIO_FLAG_READ, c->interrupt_callback, &tmp, s->protocol_whitelist, s->protocol_blacklist);
     if (ret >= 0) {
         // update cookies on http response with setcookies.
         char *new_cookies = NULL;
@@ -1225,7 +1225,7 @@ static int parse_manifest(AVFormatContext *s, const char *url, AVIOContext *in)
         close_in = 1;
 
         av_dict_copy(&opts, c->avio_opts, 0);
-        ret = avio_open2(&in, url, AVIO_FLAG_READ, c->interrupt_callback, &opts);
+        ret = ffio_open_whitelist(&in, url, AVIO_FLAG_READ, c->interrupt_callback, &opts, s->protocol_whitelist, s->protocol_blacklist);
         av_dict_free(&opts);
         if (ret < 0)
             return ret;