[network-manager-openvpn] service: cleanup get_detail()

[Thomas Haller <thaller src gnome org>]

commit 1c2b67e5e0d848ff086185346db3f420bdcc66b9
Author: Thomas Haller <thaller redhat com>
Date:   Wed Apr 5 12:32:15 2017 +0200

    service: cleanup get_detail()

 src/nm-openvpn-service.c |   60 ++++++++++++++++-----------------------------
 1 files changed, 21 insertions(+), 39 deletions(-)
---
diff --git a/src/nm-openvpn-service.c b/src/nm-openvpn-service.c
index 20f86bf..d71ed62 100644
--- a/src/nm-openvpn-service.c
+++ b/src/nm-openvpn-service.c
@@ -614,33 +614,22 @@ ovpn_quote_string (const char *unquoted)
        return quoted;
 }
 
-/* sscanf is evil, and since we can't use glib regexp stuff since it's still
- * too new for some distros, do a simple match here.
- */
 static char *
 get_detail (const char *input, const char *prefix)
 {
-       char *ret = NULL;
-       guint32 i = 0;
-       const char *p, *start;
+       const char *end;
 
-       g_return_val_if_fail (prefix != NULL, NULL);
+       nm_assert (prefix);
 
        if (!g_str_has_prefix (input, prefix))
                return NULL;
 
        /* Grab characters until the next ' */
-       p = start = input + strlen (prefix);
-       while (*p) {
-               if (*p == '\'') {
-                       ret = g_malloc0 (i + 1);
-                       strncpy (ret, start, i);
-                       break;
-               }
-               p++, i++;
-       }
-
-       return ret;
+       input += strlen (prefix);
+       end = strchr (input, '\'');
+       if (end)
+               return g_strndup (input, end - input);
+       return NULL;
 }
 
 /* Parse challenge response protocol message of the form
@@ -649,10 +638,10 @@ get_detail (const char *input, const char *prefix)
 static gboolean
 parse_challenge (const char *failure_reason, char **challenge_state_id, char **challenge_text)
 {
-       char *colon[4];
-       int challenge_len;
+       const char *colon[4];
 
-       if (!(failure_reason && !strncmp (failure_reason, "CRV1:", 5)))
+       if (   !failure_reason
+           || !g_str_has_prefix (failure_reason, "CRV1:"))
                return FALSE;
 
        colon[0] = strchr (failure_reason, ':');
@@ -671,11 +660,8 @@ parse_challenge (const char *failure_reason, char **challenge_state_id, char **c
        if (!colon[3])
                return FALSE;
 
-       challenge_len = colon[2] - colon[1] - 1;
-       *challenge_state_id = g_memdup (colon[1] + 1, challenge_len + 1);
-       (*challenge_state_id)[challenge_len] = '\0';
+       *challenge_state_id = g_strndup (colon[1] + 1, colon[2] - colon[1] - 1);
        *challenge_text = g_strdup (colon[3] + 1);
-
        return TRUE;
 }
 
@@ -728,20 +714,17 @@ handle_auth (NMOpenvpnPluginIOData *io_data,
                        username = io_data->default_username;
 
                if (username != NULL && io_data->password != NULL && io_data->challenge_state_id) {
-                       char *response = g_strdup_printf ("CRV1::%s::%s",
-                                                         io_data->challenge_state_id,
-                                                         io_data->password);
+                       gs_free char *response = NULL;
+
+                       response = g_strdup_printf ("CRV1::%s::%s",
+                                                   io_data->challenge_state_id,
+                                                   io_data->password);
                        write_user_pass (io_data->socket_channel,
                                         requested_auth,
                                         username,
                                         response);
-                       g_free (response);
-
-                       /* Avoid re-using challenge state. */
-                       g_free (io_data->challenge_state_id);
-                       io_data->challenge_state_id = NULL;
-                       g_free (io_data->challenge_text);
-                       io_data->challenge_text = NULL;
+                       nm_clear_g_free (&io_data->challenge_state_id);
+                       nm_clear_g_free (&io_data->challenge_text);
                } else if (username != NULL && io_data->password != NULL) {
                        write_user_pass (io_data->socket_channel,
                                         requested_auth,
@@ -874,16 +857,15 @@ handle_management_socket (NMOpenvpnPlugin *plugin,
                gboolean fail = TRUE;
 
                if (!strcmp (auth, "Auth")) {
-                       char *failure_reason = get_detail (auth, ">PASSWORD:Verification Failed: 'Auth' ['");
+                       gs_free char *failure_reason = NULL;
 
+                       failure_reason = get_detail (auth, ">PASSWORD:Verification Failed: 'Auth' ['");
                        if (parse_challenge (failure_reason, &priv->io_data->challenge_state_id, 
&priv->io_data->challenge_text)) {
                                _LOGD ("Received challenge '%s' for state '%s'",
                                       priv->io_data->challenge_state_id,
                                       priv->io_data->challenge_text);
-                       } else {
+                       } else
                                _LOGW ("Password verification failed");
-                       }
-                       g_free(failure_reason);
 
                        if (priv->interactive) {
                                /* Clear existing password in interactive mode, openvpn