From 6fc0d9657d169aea8e05874c7f953f47c82deb33 Mon Sep 17 00:00:00 2001
From: manuel <manuel@mausz.at>
Date: Fri, 24 Jul 2015 14:16:16 +0200
Subject: update DANE support to libval 2.1 (+fixes)

---
 qmail-remote.c | 55 +++++++++++++++++++++++++++++++++++--------------------
 1 file changed, 35 insertions(+), 20 deletions(-)

diff --git a/qmail-remote.c b/qmail-remote.c
index ece335d..4119228 100644
--- a/qmail-remote.c
+++ b/qmail-remote.c
@@ -74,6 +74,7 @@ char **myargv;
 val_context_t *dane_context = NULL;
 int dane_context_failed = 0;
 struct val_danestatus *dane_status = NULL;
+struct val_ssl_data *dane_ssl_data = NULL;
 #endif
 
 void out(s) char *s; { if (substdio_puts(subfdoutsmall,s) == -1) _exit(0); }
@@ -301,7 +302,7 @@ void smtp_quit()
   /* waiting for remote side is just too ridiculous */
 }
 
-void quit2(char *prepend, char *append, int flagdie)
+void quit2(const char *prepend, const char *append, int flagdie)
 {
   smtp_quit();
   out(prepend);
@@ -430,25 +431,26 @@ int tls_init()
   int tls_required = (smtps || servercert != NULL);
 
   if (partner_fqdn && !servercert && !dane_context_failed) {
-    if (val_create_context(NULL, &dane_context) == VAL_NO_ERROR) {
+    if (dane_context == NULL && val_create_context(NULL, &dane_context)
+        != VAL_NO_ERROR) {
+      dane_context_failed = 1;
+      out("lUnable to initialize libval context\n");
+      zeroflush();
+    }
+
+    if (dane_context) {
+      val_free_dane(dane_status);
+      val_free_dane_ssl(dane_ssl_data);
+
       /* DANE: lookup TLSA records */
       struct val_daneparams dane_params = {
         .port  = smtp_port,
         .proto = DANE_PARAM_PROTO_TCP
       };
-      if (dane_status != NULL)
-        val_free_dane(dane_status);
       dane_retval = val_getdaneinfo(dane_context, partner_fqdn, &dane_params, &dane_status);
-      if (dane_status == NULL) // insecure domain without TLSA RR will return VAL_DANE_NOERROR
-        dane_retval = VAL_DANE_CHECK_FAILED;
-      else if (dane_retval == VAL_DANE_NOERROR)
+      if (dane_retval == VAL_DANE_NOERROR)
         tls_required = 1;
     }
-    else {
-      dane_context_failed = 1;
-      out("lUnable to initialize libval context\n");
-      zeroflush();
-    }
   }
 
   if (!smtps) {
@@ -480,6 +482,19 @@ int tls_init()
     /* set the callback here; SSL_set_verify didn't work before 0.9.6c */
     SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER, verify_cb);
   }
+  else if (dane_retval == VAL_DANE_NOERROR) {
+    /* DANE: treat PKIX-EE as it were DANE-EE */
+    struct val_danestatus *dane_cur;
+    for (dane_cur = dane_status; dane_cur; dane_cur = dane_cur->next) {
+      if (dane_cur->usage == DANE_USE_SVC_CONSTRAINT)
+        dane_cur->usage = DANE_USE_DOMAIN_ISSUED;
+    }
+    /* DANE: set verify callback */
+    int err = val_enable_dane_ssl(dane_context, ctx, partner_fqdn, dane_status,
+        &dane_ssl_data);
+    if (err != VAL_NO_ERROR)
+      tls_quit("ZCould not enable dane verification", p_val_error(err));
+  }
 
   /* let the other side complain if it needs a cert and we don't have one */
   if (SSL_CTX_use_certificate_chain_file(ctx, CLIENTCERT))
@@ -532,10 +547,12 @@ int tls_init()
     if (tls_required)
       tls_quit("ZTLS connect failed", ssl_error_str());
     else {
-      smtp_quit();
-
-      out("lTLS connect failed: ");
-      out(ssl_error_str());
+      out("lTLS connect failed");
+      const char *err = ssl_error_str();
+      if (err) {
+        out(": ");
+        out(err);
+      }
       out("; retrying without TLS\n");
       zeroflush();
 
@@ -597,11 +614,9 @@ int tls_init()
 
     X509_free(peercert);
   }
-  /* DANE: verify tls connection */
+  /* DANE: verify result */
   else if (dane_retval == VAL_DANE_NOERROR) {
-    int do_certcheck = 0; // ignored. DANE SMTP doesn't do any PKIX checks
-    dane_retval = val_dane_check(dane_context, ssl, dane_status, &do_certcheck);
-    if (dane_retval != VAL_DANE_NOERROR) {
+    if (!SSL_get_peer_certificate(ssl) || SSL_get_verify_result(ssl) != X509_V_OK) {
       out("lNo TLSA record matched: ");
       out(partner_fqdn);
       quit2("/", NULL, 0);
-- 
cgit v1.2.3