While Connection: keep-alive should be the default it seems that at least some of the CA repositories fail to behave like that. Adding back the Connection header seems to fix this and delta downloads go faster again.
-- :wq Claudio Index: http.c =================================================================== RCS file: /cvs/src/usr.sbin/rpki-client/http.c,v retrieving revision 1.38 diff -u -p -r1.38 http.c --- http.c 1 Sep 2021 09:39:14 -0000 1.38 +++ http.c 9 Sep 2021 07:26:35 -0000 @@ -1026,6 +1026,7 @@ http_request(struct http_connection *con conn->bufpos = 0; if ((r = asprintf(&conn->buf, "GET /%s HTTP/1.1\r\n" + "Connection: keep-alive\r\n" "Host: %s\r\n" "Accept-Encoding: identity\r\n" "User-Agent: " HTTP_USER_AGENT "\r\n"