# HG changeset patch
# Parent  6a07f127a10b06c5314e76713bebce46f40c602a
Guard XMPP password with option guard

  * instead of filtering access to stored in public place
    restricted data, better store restricted data somewhere else
  * add xmpp_init() and xmpp_have_password (non-api)

diff -r 6a07f127a10b mcabber/mcabber/commands.c
--- a/mcabber/mcabber/commands.c	Fri Mar 04 13:54:13 2016 +0200
+++ b/mcabber/mcabber/commands.c	Fri Mar 04 13:55:29 2016 +0200
@@ -2303,10 +2303,8 @@
 
 static void list_option_cb(char *k, char *v, void *f)
 {
-  if (strcmp(k, "password")) {
-    GSList **list = f;
-    *list = g_slist_insert_sorted(*list, k, (GCompareFunc)strcmp);
-  }
+  GSList **list = f;
+  *list = g_slist_insert_sorted(*list, k, (GCompareFunc)strcmp);
 }
 
 static void do_set(char *arg)
diff -r 6a07f127a10b mcabber/mcabber/main.c
--- a/mcabber/mcabber/main.c	Fri Mar 04 13:54:13 2016 +0200
+++ b/mcabber/mcabber/main.c	Fri Mar 04 13:55:29 2016 +0200
@@ -451,6 +451,7 @@
   scr_init_locale_charset();
   ut_init_debug();
   help_init();
+  xmpp_init();
 
   /* Parsing config file... */
   ret = cfg_read_file(configFile, TRUE);
@@ -472,19 +473,21 @@
 
   /* If no password is stored, we ask for it before entering
      ncurses mode -- unless the username is unknown. */
-  if (settings_opt_get("jid") && !settings_opt_get("password")) {
+  if (settings_opt_get("jid") && !xmpp_have_password) {
     const char *pass_eval = settings_opt_get("password_eval");
     if (pass_eval) {
       int status = 0;
       char *pwd = password_eval(pass_eval, &status);
       if (status == 0 && pwd) {
+        /* Will be intercepted by guard */
         settings_set(SETTINGS_TYPE_OPTION, "password", pwd);
       }
       g_free(pwd);
     }
     // If the password is still unset, ask the user...
-    if (!settings_opt_get("password")) {
+    if (!xmpp_have_password) {
       char *pwd = ask_password("your Jabber password");
+      /* Will be intercepted by guard */
       settings_set(SETTINGS_TYPE_OPTION, "password", pwd);
       g_free(pwd);
     }
diff -r 6a07f127a10b mcabber/mcabber/xmpp.c
--- a/mcabber/mcabber/xmpp.c	Fri Mar 04 13:54:13 2016 +0200
+++ b/mcabber/mcabber/xmpp.c	Fri Mar 04 13:55:29 2016 +0200
@@ -23,6 +23,8 @@
  */
 #include <stdlib.h>
 #include <string.h>
+#include <sys/mman.h>
+#include <errno.h>
 
 #include "xmpp.h"
 #include "xmpp_helper.h"
@@ -58,6 +60,9 @@
 static enum imstatus mywantedstatus = available;
 gchar *mystatusmsg;
 
+static char *xmpp_password = NULL;
+gboolean xmpp_have_password = FALSE;
+
 char imstatus2char[imstatus_size+1] = {
     '_', 'o', 'f', 'd', 'n', 'a', 'i', '\0'
 };
@@ -816,16 +821,15 @@
   GError *error = NULL;
 
   if (success) {
-    const char *password, *resource;
+    const char *resource;
     char *username;
     username   = jid_get_username(settings_opt_get("jid"));
-    password   = settings_opt_get("password");
     resource   = strchr(lm_connection_get_jid(connection),
                         JID_RESOURCE_SEPARATOR);
     if (resource)
       resource++;
 
-    if (!lm_connection_authenticate(lconnection, username, password, resource,
+    if (!lm_connection_authenticate(lconnection, username, xmpp_password, resource,
                                     connection_auth_cb, NULL, FALSE, &error)) {
       scr_LogPrint(LPRINT_LOGNORM, "Failed to authenticate: %s",
                    error->message);
@@ -1765,13 +1769,37 @@
   }
 }
 
+static gchar *xmpp_password_guard(const gchar *key, const gchar *new_value)
+{
+  if (xmpp_password) {
+    size_t len = strlen(xmpp_password);
+    memset(xmpp_password, '\0', len);
+    if (munlock(xmpp_password, len))
+      scr_LogPrint(LPRINT_DEBUG, "password guard: Cannot unlock memory: %s.",
+                   strerror(errno));
+    g_free(xmpp_password);
+  }
+  xmpp_password = g_strdup(new_value);
+  if (xmpp_password) {
+    if (mlock(xmpp_password, strlen(xmpp_password)))
+      scr_LogPrint(LPRINT_DEBUG, "password guard: Cannot lock memory: %s.",
+                   strerror(errno));
+    xmpp_have_password = TRUE;
+  }
+  return NULL;
+}
+
+void xmpp_init(void)
+{
+  settings_set_guard("password", xmpp_password_guard);
+}
 
 //  xmpp_connect()
 // Return a non-zero value if there's an obvious problem
 // (no JID, no password, etc.)
 gint xmpp_connect(void)
 {
-  const char *userjid, *password, *resource, *servername, *ssl_fpr;
+  const char *userjid, *resource, *servername, *ssl_fpr;
   char *dynresource = NULL;
 #ifndef LOUDMOUTH_USES_SHA256
   char fpr[FINGERPRINT_LENGTH] = {0};
@@ -1790,7 +1818,6 @@
 
   servername  = settings_opt_get("server");
   userjid     = settings_opt_get("jid");
-  password    = settings_opt_get("password");
   resource    = settings_opt_get("resource");
   proxy_host  = settings_opt_get("proxy_host");
   ssl_fpr     = settings_opt_get("ssl_fingerprint");
@@ -1799,7 +1826,7 @@
     scr_LogPrint(LPRINT_LOGNORM, "Your JID has not been specified!");
     return -1;
   }
-  if (!password) {
+  if (!xmpp_password) {
     scr_LogPrint(LPRINT_LOGNORM, "Your password has not been specified!");
     return -1;
   }
diff -r 6a07f127a10b mcabber/mcabber/xmpp.h
--- a/mcabber/mcabber/xmpp.h	Fri Mar 04 13:54:13 2016 +0200
+++ b/mcabber/mcabber/xmpp.h	Fri Mar 04 13:55:29 2016 +0200
@@ -34,7 +34,9 @@
 
 extern LmConnection* lconnection;
 extern LmSSL* lssl;
+extern gboolean xmpp_have_password; /* private */
 
+void xmpp_init(void); /* private */
 int  xmpp_connect(void);
 void xmpp_disconnect(void);
 gboolean xmpp_is_online(void);