BUG/MEDIUM: ssl/crt-list: correctly insert crt-list line if crt already loaded

In issue #940, it was reported that the crt-list does not work correctly
anymore. Indeed when inserting a crt-list line which use a certificate
previously seen in the crt-list, this one won't be inserted in the SNI
list and will be silently ignored.

This bug was introduced by commit  47da821 "MEDIUM: ssl: emulates the
multi-cert bundles in the crtlist".

This patch also includes a reg-test which tests this issue.

This bugfix must be backported in 2.3.

reg-tests/ssl/simple.crt-list

@@ -0,0 +1,5 @@
+common.pem record1.bug940.domain.tld
+common.pem record2.bug940.domain.tld
+ecdsa.pem record3.bug940.domain.tld
+ecdsa.pem record4.bug940.domain.tld
+

reg-tests/ssl/ssl_simple_crt-list.vtc

@@ -0,0 +1,51 @@
+#REGTEST_TYPE=bug
+varnishtest "Test for the bug #940"
+# Test that the SNI are correcly inserted with the same file multiple times.
+
+#REQUIRE_VERSION=2.2
+#REQUIRE_OPTIONS=OPENSSL
+feature ignore_unknown_macro
+
+server s1 -repeat 4 {
+    rxreq
+    txresp
+} -start
+
+haproxy h1 -conf {
+    global
+        tune.ssl.default-dh-param 2048
+        crt-base ${testdir}
+        stats socket "${tmpdir}/h1/stats" level admin
+
+    defaults
+        mode http
+        option httplog
+        log stderr local0 debug err
+        option logasap
+        timeout connect 1s
+        timeout client  1s
+        timeout server  1s
+
+
+    listen clear-lst
+        bind "fd@${clearlst}"
+        balance roundrobin
+        server s1 "${tmpdir}/ssl.sock" ssl verify none sni str(record1.bug940.domain.tld)
+        server s2 "${tmpdir}/ssl.sock" ssl verify none sni str(record2.bug940.domain.tld)
+        server s3 "${tmpdir}/ssl.sock" ssl verify none sni str(record3.bug940.domain.tld)
+        server s4 "${tmpdir}/ssl.sock" ssl verify none sni str(record4.bug940.domain.tld)
+
+    listen ssl-lst
+        mode http
+        ${no-htx} option http-use-htx
+        bind "${tmpdir}/ssl.sock" ssl strict-sni crt-list ${testdir}/simple.crt-list
+
+        server s1 ${s1_addr}:${s1_port}
+} -start
+
+
+client c1 -repeat 4 -connect ${h1_clearlst_sock} {
+    txreq
+    rxresp
+    expect resp.status == 200
+} -run

src/ssl_crtlist.c

@@ -598,6 +598,12 @@ int crtlist_parse_file(char *file, struct bind_conf *bind_conf, struct proxy *cu
 					}
 				}
 			}
+		} else {
+			entry->node.key = ckchs;
+			entry->crtlist = newlist;
+			ebpt_insert(&newlist->entries, &entry->node);
+			LIST_ADDQ(&newlist->ord_entries, &entry->by_crtlist);
+			LIST_ADDQ(&ckchs->crtlist_entry, &entry->by_ckch_store);
 		}
 		entry = NULL;
 	}