Add support for non-interactive shell to nasl_ssh_shell_open(). (backport #744)

CHANGELOG.md

@@ -7,8 +7,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ## [21.04.1] (unreleased)
 
 ### Added
-- Improve nasl linter to catch more cases of undeclared variables. [#728][(https://github.com/greenbone/openvas-scanner/pull/728)
-- Add deprecation warning for source_iface related settings which will be removed with the 21.10 release. [#732][(https://github.com/greenbone/openvas-scanner/pull/732)
+- Improve nasl linter to catch more cases of undeclared variables. [#728](https://github.com/greenbone/openvas-scanner/pull/728)
+- Add deprecation warning for source_iface related settings which will be removed with the 21.10 release. [#732](https://github.com/greenbone/openvas-scanner/pull/732)
+- New Credentials for SSH to get su privileges. Backport of [#744](https://github.com/greenbone/openvas-scanner/pull/744). [#753](https://github.com/greenbone/openvas-scanner/pull/753)
 
 ### Changed
 - Update default log config [#711](https://github.com/greenbone/openvas-scanner/pull/711)

nasl/nasl_ssh.c

@@ -1649,23 +1649,30 @@ request_ssh_shell_alarm (int signal)
  * @brief Open a shell on an ssh channel.
  *
  * @param[in]   channel     SSH Channel.
+ * @param[in]   pty         1 interactive shell, 0 non-intercative shell
  *
  * @return 0 if success, -1 if error.
  */
 static int
-request_ssh_shell (ssh_channel channel)
+request_ssh_shell (ssh_channel channel, int pty)
 {
   assert (channel);
 
   /* Work-around for LibSSH calling poll() with an infinite timeout. */
   signal (SIGALRM, request_ssh_shell_alarm);
   alarm (30);
-  if (ssh_channel_request_pty (channel))
-    return -1;
-  if (ssh_channel_change_pty_size (channel, 80, 24))
-    return -1;
+
+  if (pty == 1)
+    {
+      if (ssh_channel_request_pty (channel))
+        return -1;
+
+      if (ssh_channel_change_pty_size (channel, 80, 24))
+        return -1;
+    }
   if (ssh_channel_request_shell (channel))
     return -1;
+
   alarm (0);
   signal (SIGALRM, _exit);
 
@@ -1679,6 +1686,8 @@ request_ssh_shell (ssh_channel channel)
  * @nasluparam
  *
  * - An ssh session id.
+ * - Named param 'pty' to enable/disable the interactive shell. Default is 1
+ *   interactive.
  *
  * @naslret An int on success or NULL on error.
  *
@@ -1689,12 +1698,14 @@ request_ssh_shell (ssh_channel channel)
 tree_cell *
 nasl_ssh_shell_open (lex_ctxt *lexic)
 {
-  int tbl_slot, session_id;
+  int tbl_slot, session_id, pty;
   ssh_channel channel;
   ssh_session session;
   tree_cell *retc;
 
   session_id = get_int_var_by_num (lexic, 0, -1);
+  pty = get_int_var_by_name (lexic, "pty", 1);
+
   if (!verify_session_id (session_id, "ssh_shell_open", &tbl_slot, lexic))
     return NULL;
   session = session_table[tbl_slot].session;
@@ -1711,7 +1722,7 @@ nasl_ssh_shell_open (lex_ctxt *lexic)
       return NULL;
     }
 
-  if (request_ssh_shell (channel))
+  if (request_ssh_shell (channel, pty))
     {
       g_message ("Function %s (calling internal function %s) called from %s: "
                  "request_ssh_shell: %s",