server: allow custom server banners (bug #83)

include/libssh/session.h

@@ -175,6 +175,7 @@ struct ssh_session_struct {
         char *knownhosts;
         char *wanted_methods[10];
         char *ProxyCommand;
+        char *custombanner;
         unsigned long timeout; /* seconds */
         unsigned long timeout_usec;
         unsigned int port;

src/bind.c

@@ -413,7 +413,8 @@ int ssh_bind_accept_fd(ssh_bind sshbind, ssh_session session, socket_t fd){
     }
 
     session->common.log_verbosity = sshbind->common.log_verbosity;
-
+    if(sshbind->banner != NULL)
+    	session->opts.custombanner = strdup(sshbind->banner);
     ssh_socket_free(session->socket);
     session->socket = ssh_socket_new(session);
     if (session->socket == NULL) {

src/client.c

@@ -152,7 +152,15 @@ int ssh_send_banner(ssh_session session, int server) {
   banner = session->version == 1 ? CLIENTBANNER1 : CLIENTBANNER2;
 
   if (server) {
+    if(session->opts.custombanner == NULL){
     	session->serverbanner = strdup(banner);
+    } else {
+    	session->serverbanner = malloc(strlen(session->opts.custombanner) + 9);
+    	if(!session->serverbanner)
+    		goto end;
+    	strcpy(session->serverbanner, "SSH-2.0-");
+    	strcat(session->serverbanner, session->opts.custombanner);
+    }
     if (session->serverbanner == NULL) {
       goto end;
     }