GUAC-1264: Require explicit free for users and sessions. Ensure SSH client data is zeroed upon allocation.

src/common-ssh/guac_sftp.c

@@ -707,8 +707,5 @@ void guac_common_ssh_destroy_sftp_filesystem(guac_object* filesystem) {
     /* Clean up the SFTP filesystem object */
     guac_client_free_object(sftp_data->ssh_session->client, filesystem);
 
-    /* Disconnect SSH session corresponding to the SFTP session */
-    guac_common_ssh_destroy_session(sftp_data->ssh_session);
-
 }
 

src/common-ssh/guac_sftp.h

@@ -110,7 +110,8 @@ guac_object* guac_common_ssh_create_sftp_filesystem(
 
 /**
  * Destroys the given filesystem object, disconnecting from SFTP and freeing
- * and associated resources.
+ * and associated resources. Any associated session or user objects must be
+ * explicitly destroyed.
  *
  * @param object
  *     The filesystem object to destroy.

src/common-ssh/guac_ssh.c

@@ -504,10 +504,6 @@ void guac_common_ssh_destroy_session(guac_common_ssh_session* session) {
     libssh2_session_disconnect(session->session, "Bye");
     libssh2_session_free(session->session);
 
-    /* Destroy associated user */
-    if (session->user)
-        guac_common_ssh_destroy_user(session->user);
-
     /* Free all other data */
     free(session);
 

src/common-ssh/guac_ssh.h

@@ -80,6 +80,9 @@ void guac_common_ssh_uninit();
  * Connects to the SSH server running at the given hostname and port, and
  * authenticates as the given user. If an error occurs while connecting or
  * authenticating, the Guacamole client will automatically and fatally abort.
+ * The user object provided must eventually be explicitly destroyed, but should
+ * not be destroyed until this session is destroyed, assuming the session is
+ * successfully created.
  *
  * @param client
  *     The Guacamole client that will be using SSH.
@@ -91,8 +94,7 @@ void guac_common_ssh_uninit();
  *     The port to connect to on the given hostname.
  *
  * @param user
- *     The user to authenticate as, once connected. This user will be
+ *     The user to authenticate as, once connected.
- *     automatically destroyed when this session is destroyed.
  *
  * @return
  *     A new SSH session if the connection and authentication succeed, or NULL
@@ -103,7 +105,8 @@ guac_common_ssh_session* guac_common_ssh_create_session(guac_client* client,
 
 /**
  * Disconnects and destroys the given SSH session, freeing all associated
- * resources.
+ * resources. Any associated user must be explicitly destroyed, and will not
+ * be destroyed automatically.
  *
  * @param session
  *     The SSH session to destroy.

src/protocols/ssh/client.c

@@ -120,11 +120,10 @@ int guac_client_init(guac_client* client, int argc, char** argv) {
 
     guac_socket* socket = client->socket;
 
-    ssh_guac_client_data* client_data = malloc(sizeof(ssh_guac_client_data));
+    ssh_guac_client_data* client_data = calloc(1, sizeof(ssh_guac_client_data));
 
     /* Init client data */
     client->data = client_data;
-    client_data->term_channel = NULL;
 
     if (argc != SSH_ARGS_COUNT) {
         guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Wrong number of arguments");
@@ -159,7 +158,6 @@ int guac_client_init(guac_client* client, int argc, char** argv) {
 
     /* Parse SFTP enable */
     client_data->enable_sftp = strcmp(argv[IDX_ENABLE_SFTP], "true") == 0;
-    client_data->sftp_filesystem = NULL;
 
 #ifdef ENABLE_SSH_AGENT
     client_data->enable_agent = strcmp(argv[IDX_ENABLE_AGENT], "true") == 0;

src/protocols/ssh/client.h

@@ -27,6 +27,7 @@
 #include "config.h"
 
 #include "guac_ssh.h"
+#include "guac_ssh_user.h"
 #include "sftp.h"
 #include "terminal.h"
 
@@ -109,11 +110,21 @@ typedef struct ssh_guac_client_data {
      */
     pthread_t client_thread;
 
+    /**
+     * The user and credentials to use for all SSH sessions.
+     */
+    guac_common_ssh_user* user;
+
     /**
      * SSH session, used by the SSH client thread.
      */
     guac_common_ssh_session* session;
 
+    /**
+     * SFTP session, used by the SFTP client/filesystem.
+     */
+    guac_common_ssh_session* sftp_session;
+
     /**
      * The filesystem object exposed for the SFTP session.
      */

src/protocols/ssh/guac_handlers.c

@@ -102,14 +102,20 @@ int ssh_guac_client_free_handler(guac_client* client) {
     /* Free channels */
     libssh2_channel_free(guac_client_data->term_channel);
 
-    /* Clean up the SFTP filesystem object */
+    /* Clean up the SFTP filesystem object and session */
-    if (guac_client_data->sftp_filesystem)
+    if (guac_client_data->sftp_filesystem) {
         guac_common_ssh_destroy_sftp_filesystem(guac_client_data->sftp_filesystem);
+        guac_common_ssh_destroy_session(guac_client_data->sftp_session);
+    }
 
     /* Free session */
     if (guac_client_data->session != NULL)
         guac_common_ssh_destroy_session(guac_client_data->session);
 
+    /* Free user */
+    if (guac_client_data->user != NULL)
+        guac_common_ssh_destroy_user(guac_client_data->user);
+
     /* Free generic data struct */
     free(client->data);
 

src/protocols/ssh/ssh_client.c

@@ -130,12 +130,16 @@ static guac_common_ssh_user* guac_ssh_get_user(guac_client* client) {
 
     } /* end if key given */
 
-    /* Otherwise, get password if not provided */
+    /* Otherwise, use password */
-    else if (client_data->password[0] == 0) {
+    else {
 
-        guac_terminal_prompt(client_data->term, "Password: ",
+        /* Get password if not provided */
-                client_data->password, sizeof(client_data->password), false);
+        if (client_data->password[0] == 0)
+            guac_terminal_prompt(client_data->term, "Password: ",
+                    client_data->password, sizeof(client_data->password),
+                    false);
 
+        /* Set provided password */
         guac_common_ssh_user_set_password(user, client_data->password);
 
     }
@@ -181,7 +185,7 @@ void* ssh_client_thread(void* data) {
         return NULL;
 
     /* Get user and credentials */
-    guac_common_ssh_user* user = guac_ssh_get_user(client);
+    client_data->user = guac_ssh_get_user(client);
 
     /* Send new name */
     char name[1024];
@@ -191,7 +195,7 @@ void* ssh_client_thread(void* data) {
 
     /* Open SSH session */
     client_data->session = guac_common_ssh_create_session(client,
-            client_data->hostname, client_data->port, user);
+            client_data->hostname, client_data->port, client_data->user);
     if (client_data->session == NULL) {
         /* Already aborted within guac_common_ssh_create_session() */
         return NULL;
@@ -229,17 +233,18 @@ void* ssh_client_thread(void* data) {
 
         /* Create SSH session specific for SFTP */
         guac_client_log(client, GUAC_LOG_DEBUG, "Reconnecting for SFTP...");
-        guac_common_ssh_session* sftp_ssh_session =
+        client_data->sftp_session =
             guac_common_ssh_create_session(client, client_data->hostname,
-                    client_data->port, user);
+                    client_data->port, client_data->user);
-        if (sftp_ssh_session == NULL) {
+        if (client_data->sftp_session == NULL) {
             /* Already aborted within guac_common_ssh_create_session() */
             return NULL;
         }
 
         /* Request SFTP */
         client_data->sftp_filesystem =
-            guac_common_ssh_create_sftp_filesystem(sftp_ssh_session, "/");
+            guac_common_ssh_create_sftp_filesystem(
+                    client_data->sftp_session, "/");
 
         /* Set generic (non-filesystem) file upload handler */
         client->file_handler = guac_sftp_file_handler;