DANE support structures, constructructors and accessors

Also tweak some of the code in demos/bio, to enable interactive
testing of BIO_s_accept's use of SSL_dup.  Changed the sconnect
client to authenticate the server, which now exercises the new
SSL_set1_host() function.

Reviewed-by: Richard Levitte <levitte@openssl.org>

demos/bio/saccept.c

@@ -18,16 +18,30 @@
 
 #define CERT_FILE       "server.pem"
 
-BIO *in = NULL;
+static int done = 0;
 
-void close_up()
+void interrupt()
 {
-    BIO_free(in);
+    done = 1;
+}
+
+void sigsetup(void)
+{
+    struct sigaction sa;
+
+    /*
+     * Catch at most once, and don't restart the accept system call.
+     */
+    sa.sa_flags = SA_RESETHAND;
+    sa.sa_handler = interrupt;
+    sigemptyset(&sa.sa_mask);
+    sigaction(SIGINT, &sa, NULL);
 }
 
 int main(int argc, char *argv[])
 {
     char *port = NULL;
+    BIO *in = NULL;
     BIO *ssl_bio, *tmp;
     SSL_CTX *ctx;
     char buf[512];
@@ -38,15 +52,13 @@ int main(int argc, char *argv[])
     else
         port = argv[1];
 
-    signal(SIGINT, close_up);
-
     SSL_load_error_strings();
 
     /* Add ciphers and message digests */
     OpenSSL_add_ssl_algorithms();
 
     ctx = SSL_CTX_new(TLS_server_method());
-    if (!SSL_CTX_use_certificate_file(ctx, CERT_FILE, SSL_FILETYPE_PEM))
+    if (!SSL_CTX_use_certificate_chain_file(ctx, CERT_FILE))
         goto err;
     if (!SSL_CTX_use_PrivateKey_file(ctx, CERT_FILE, SSL_FILETYPE_PEM))
         goto err;
@@ -66,6 +78,9 @@ int main(int argc, char *argv[])
      */
     BIO_set_accept_bios(in, ssl_bio);
 
+    /* Arrange to leave server loop on interrupt */
+    sigsetup();
+
  again:
     /*
      * The first call will setup the accept socket, and the second will get a
@@ -76,7 +91,7 @@ int main(int argc, char *argv[])
     if (BIO_do_accept(in) <= 0)
         goto err;
 
-    for (;;) {
+    while (!done) {
         i = BIO_read(in, buf, 512);
         if (i == 0) {
             /*