# HG changeset patch
# User Vladimir Homutov <vl@nginx.com>
# Date 1600433617 -10800
# Node ID 2727d402e5a5e6f0fd5431182dd5f75f361902c6
# Parent  b383120afca3be162551b884e88f889375b734ee
QUIC: switched to using fixed-length server connection IDs.

diff --git a/src/event/ngx_event_quic.c b/src/event/ngx_event_quic.c
--- a/src/event/ngx_event_quic.c
+++ b/src/event/ngx_event_quic.c
@@ -910,24 +910,17 @@ ngx_quic_negotiate_version(ngx_connectio
 static ngx_int_t
 ngx_quic_new_dcid(ngx_connection_t *c, ngx_str_t *odcid)
 {
-    uint8_t                 len;
     ngx_quic_connection_t  *qc;
 
     qc = c->quic;
 
-    if (RAND_bytes(&len, sizeof(len)) != 1) {
-        return NGX_ERROR;
-    }
-
-    len = len % 10 + 10;
-
-    qc->dcid.len = len;
-    qc->dcid.data = ngx_pnalloc(c->pool, len);
+    qc->dcid.len = NGX_QUIC_SERVER_CID_LEN;
+    qc->dcid.data = ngx_pnalloc(c->pool, NGX_QUIC_SERVER_CID_LEN);
     if (qc->dcid.data == NULL) {
         return NGX_ERROR;
     }
 
-    if (RAND_bytes(qc->dcid.data, len) != 1) {
+    if (RAND_bytes(qc->dcid.data, NGX_QUIC_SERVER_CID_LEN) != 1) {
         return NGX_ERROR;
     }
 
diff --git a/src/event/ngx_event_quic.h b/src/event/ngx_event_quic.h
--- a/src/event/ngx_event_quic.h
+++ b/src/event/ngx_event_quic.h
@@ -54,6 +54,8 @@
 
 #define NGX_QUIC_STREAM_BUFSIZE              65536
 
+#define NGX_QUIC_SERVER_CID_LEN              20
+
 
 typedef struct {
     /* configurable */