Added "auth-token" client directive, which is intended to be

pushed by server, and that is used to offer a temporary session
token to clients that can be used in place of a password on
subsequent credential challenges.

This accomplishes the security benefit of preventing caching
of the real password while offering most of the advantages
of password caching, i.e. not forcing the user to re-enter
credentials for every TLS renegotiation or network hiccup.

auth-token does two things:

1. if password caching is enabled, the token replaces the
   previous password, and

2. if the management interface is active, the token is output
   to it:

     >PASSWORD:Auth-Token:<token>

Also made a minor change to HALT/RESTART processing when password
caching is enabled.  When client receives a HALT or RESTART message,
and if the message text contains a flags block (i.e. [FFF]:message),
if flag 'P' (preserve auth) is present in flags, don't purge the Auth
password.  Otherwise do purge the Auth password.

Version 2.1.3o


git-svn-id: http://svn.openvpn.net/projects/openvpn/branches/BETA21/openvpn@7088 e7ae566f-a301-0410-adde-c780ea21d3b5

1 files changed, 44 insertions, 0 deletions

diff --git a/misc.c b/misc.c
index 0f9dfcc..4a80004 100644
--- a/misc.c
+++ b/misc.c
@@ -1695,6 +1695,16 @@ purge_user_pass (struct user_pass *up, const bool force)
     }
 }
 
+void
+set_auth_token (struct user_pass *up, const char *token)
+{
+  if (token && strlen(token) && up && up->defined && !up->nocache)
+    {
+      CLEAR (up->password);
+      strncpynt (up->password, token, USER_PASS_LEN);
+    }
+}
+
 /*
  * Process string received by untrusted peer before
  * printing to console or log file.
@@ -2363,3 +2373,37 @@ openvpn_basename (const char *path)
     }
   return NULL;
 }
+
+/*
+ * Remove SESS_ID_x strings (i.e. auth tokens) from control message
+ * strings so that they will not be output to log file.
+ */
+const char *
+sanitize_control_message(const char *str, struct gc_arena *gc)
+{
+  char *ret = gc_malloc (strlen(str)+1, false, gc);
+  char *cp = ret;
+  bool redact = false;
+
+  strcpy(ret, str);
+  for (;;)
+    {
+      const char c = *cp;
+      if (c == '\0')
+	  break;
+      if (c == 'S' && !strncmp(cp, "SESS_ID_", 8))
+	{
+	  cp += 7;
+	  redact = true;
+	}
+      else
+	{
+	  if (c == ',') /* end of session id? */
+	    redact = false;
+	  if (redact)
+	    *cp = '_';
+	}
+      ++cp;
+    }
+  return ret;
+}