Merge pull request #58 from glyptodon/password-segfault

GUAC-1264: Fix segfault in password handling
This commit is contained in:
James Muehlner 2015-07-24 14:24:49 -07:00
commit 7147649347
14 changed files with 153 additions and 64 deletions

View File

@ -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);
}

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@ -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.

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@ -297,6 +297,13 @@ static int guac_common_ssh_authenticate(guac_common_ssh_session* common_session)
char* password = user->password;
guac_common_ssh_key* key = user->private_key;
/* Validate username provided */
if (username == NULL) {
guac_client_abort(client, GUAC_PROTOCOL_STATUS_CLIENT_UNAUTHORIZED,
"SSH authentication requires a username.");
return 1;
}
/* Get list of supported authentication methods */
char* user_authlist = libssh2_userauth_list(session, username,
strlen(username));
@ -309,7 +316,8 @@ static int guac_common_ssh_authenticate(guac_common_ssh_session* common_session)
/* Check if public key auth is supported on the server */
if (strstr(user_authlist, "publickey") == NULL) {
guac_client_abort(client, GUAC_PROTOCOL_STATUS_CLIENT_UNAUTHORIZED,
"Public key authentication not supported");
"Public key authentication is not supported by "
"the SSH server");
return 1;
}
@ -333,24 +341,35 @@ static int guac_common_ssh_authenticate(guac_common_ssh_session* common_session)
}
/* Authenticate with password */
if (strstr(user_authlist, "password") != NULL) {
guac_client_log(client, GUAC_LOG_DEBUG,
"Using password authentication method");
return libssh2_userauth_password(session, username, password);
/* Authenticate with password, if provided */
else if (password != NULL) {
/* Authenticate with password */
if (strstr(user_authlist, "password") != NULL) {
guac_client_log(client, GUAC_LOG_DEBUG,
"Using password authentication method");
return libssh2_userauth_password(session, username, password);
}
/* Authenticate with password via keyboard-interactive auth */
if (strstr(user_authlist, "keyboard-interactive") != NULL) {
guac_client_log(client, GUAC_LOG_DEBUG,
"Using keyboard-interactive authentication method");
return libssh2_userauth_keyboard_interactive(session, username,
&guac_common_ssh_kbd_callback);
}
/* No known authentication types available */
guac_client_abort(client, GUAC_PROTOCOL_STATUS_CLIENT_UNAUTHORIZED,
"Password and keyboard-interactive authentication are not "
"supported by the SSH server");
return 1;
}
/* Authenticate with password via keyboard-interactive auth */
if (strstr(user_authlist, "keyboard-interactive") != NULL) {
guac_client_log(client, GUAC_LOG_DEBUG,
"Using keyboard-interactive authentication method");
return libssh2_userauth_keyboard_interactive(session, username,
&guac_common_ssh_kbd_callback);
}
/* No known authentication types available */
guac_client_abort(client, GUAC_PROTOCOL_STATUS_CLIENT_BAD_TYPE,
"No known authentication methods");
/* No credentials provided */
guac_client_abort(client, GUAC_PROTOCOL_STATUS_CLIENT_UNAUTHORIZED,
"SSH authentication requires either a private key or a password.");
return 1;
}
@ -485,10 +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);

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@ -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
* automatically destroyed when this session is destroyed.
* The user to authenticate as, once connected.
*
* @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.

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@ -831,7 +831,8 @@ int guac_client_init(guac_client* client, int argc, char** argv) {
if (sftp_username[0] == '\0' && settings->username != NULL)
sftp_username = settings->username;
guac_common_ssh_user* user = guac_common_ssh_create_user(sftp_username);
guac_client_data->sftp_user =
guac_common_ssh_create_user(sftp_username);
/* Import private key, if given */
if (argv[IDX_SFTP_PRIVATE_KEY][0] != '\0') {
@ -840,10 +841,10 @@ int guac_client_init(guac_client* client, int argc, char** argv) {
"Authenticating with private key.");
/* Abort if private key cannot be read */
if (guac_common_ssh_user_import_key(user,
if (guac_common_ssh_user_import_key(guac_client_data->sftp_user,
argv[IDX_SFTP_PRIVATE_KEY],
argv[IDX_SFTP_PASSPHRASE])) {
guac_common_ssh_destroy_user(user);
guac_common_ssh_destroy_user(guac_client_data->sftp_user);
return 1;
}
@ -856,11 +857,12 @@ int guac_client_init(guac_client* client, int argc, char** argv) {
"Authenticating with password.");
/* Parse password - use RDP password by default */
const char* sftp_password = argv[IDX_SFTP_USERNAME];
const char* sftp_password = argv[IDX_SFTP_PASSWORD];
if (sftp_password[0] == '\0' && settings->password != NULL)
sftp_password = settings->password;
guac_common_ssh_user_set_password(user, sftp_password);
guac_common_ssh_user_set_password(guac_client_data->sftp_user,
sftp_password);
}
@ -875,24 +877,28 @@ int guac_client_init(guac_client* client, int argc, char** argv) {
sftp_port = "22";
/* Attempt SSH connection */
guac_common_ssh_session* session =
guac_client_data->sftp_session =
guac_common_ssh_create_session(client, sftp_hostname, sftp_port,
user);
guac_client_data->sftp_user);
/* Fail if SSH connection does not succeed */
if (session == NULL) {
if (guac_client_data->sftp_session == NULL) {
/* Already aborted within guac_common_ssh_create_session() */
guac_common_ssh_destroy_user(user);
guac_common_ssh_destroy_user(guac_client_data->sftp_user);
return 1;
}
/* Load and expose filesystem */
guac_client_data->sftp_filesystem =
guac_common_ssh_create_sftp_filesystem(session, "/");
guac_common_ssh_create_sftp_filesystem(
guac_client_data->sftp_session, "/");
/* Abort if SFTP connection fails */
if (guac_client_data->sftp_filesystem == NULL)
if (guac_client_data->sftp_filesystem == NULL) {
guac_common_ssh_destroy_session(guac_client_data->sftp_session);
guac_common_ssh_destroy_user(guac_client_data->sftp_user);
return 1;
}
/* Use SFTP for basic uploads, if drive not enabled */
if (!settings->drive_enabled)

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@ -35,6 +35,8 @@
#ifdef ENABLE_COMMON_SSH
#include "guac_sftp.h"
#include "guac_ssh.h"
#include "guac_ssh_user.h"
#endif
#ifdef HAVE_FREERDP_DISPLAY_UPDATE_SUPPORT
@ -162,6 +164,16 @@ typedef struct rdp_guac_client_data {
guac_rdp_fs* filesystem;
#ifdef ENABLE_COMMON_SSH
/**
* The user and credentials used to authenticate for SFTP.
*/
guac_common_ssh_user* sftp_user;
/**
* The SSH session used for SFTP.
*/
guac_common_ssh_session* sftp_session;
/**
* The exposed filesystem object, implemented with SFTP.
*/

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@ -36,6 +36,7 @@
#ifdef ENABLE_COMMON_SSH
#include <guac_sftp.h>
#include <guac_ssh.h>
#include <guac_ssh_user.h>
#endif
#include <freerdp/cache/cache.h>
@ -99,6 +100,14 @@ int rdp_guac_client_free_handler(guac_client* client) {
if (guac_client_data->sftp_filesystem)
guac_common_ssh_destroy_sftp_filesystem(guac_client_data->sftp_filesystem);
/* Free SFTP session */
if (guac_client_data->sftp_session)
guac_common_ssh_destroy_session(guac_client_data->sftp_session);
/* Free SFTP user */
if (guac_client_data->sftp_user)
guac_common_ssh_destroy_user(guac_client_data->sftp_user);
guac_common_ssh_uninit();
#endif

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@ -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;

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@ -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.
*/

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@ -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 */
if (guac_client_data->sftp_filesystem)
/* Clean up the SFTP filesystem object and session */
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);

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@ -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 */
else if (client_data->password[0] == 0) {
/* Otherwise, use password */
else {
guac_terminal_prompt(client_data->term, "Password: ",
client_data->password, sizeof(client_data->password), false);
/* Get password if not provided */
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);
if (sftp_ssh_session == NULL) {
client_data->port, client_data->user);
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;

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@ -372,7 +372,7 @@ int guac_client_init(guac_client* client, int argc, char** argv) {
guac_client_log(client, GUAC_LOG_DEBUG,
"Connecting via SSH for SFTP filesystem access.");
guac_common_ssh_user* user =
guac_client_data->sftp_user =
guac_common_ssh_create_user(argv[IDX_SFTP_USERNAME]);
/* Import private key, if given */
@ -382,10 +382,10 @@ int guac_client_init(guac_client* client, int argc, char** argv) {
"Authenticating with private key.");
/* Abort if private key cannot be read */
if (guac_common_ssh_user_import_key(user,
if (guac_common_ssh_user_import_key(guac_client_data->sftp_user,
argv[IDX_SFTP_PRIVATE_KEY],
argv[IDX_SFTP_PASSPHRASE])) {
guac_common_ssh_destroy_user(user);
guac_common_ssh_destroy_user(guac_client_data->sftp_user);
return 1;
}
@ -395,7 +395,8 @@ int guac_client_init(guac_client* client, int argc, char** argv) {
else {
guac_client_log(client, GUAC_LOG_DEBUG,
"Authenticating with password.");
guac_common_ssh_user_set_password(user, argv[IDX_SFTP_PASSWORD]);
guac_common_ssh_user_set_password(guac_client_data->sftp_user,
argv[IDX_SFTP_PASSWORD]);
}
/* Parse hostname - use VNC hostname by default */
@ -409,24 +410,28 @@ int guac_client_init(guac_client* client, int argc, char** argv) {
sftp_port = "22";
/* Attempt SSH connection */
guac_common_ssh_session* session =
guac_client_data->sftp_session =
guac_common_ssh_create_session(client, sftp_hostname, sftp_port,
user);
guac_client_data->sftp_user);
/* Fail if SSH connection does not succeed */
if (session == NULL) {
if (guac_client_data->sftp_session == NULL) {
/* Already aborted within guac_common_ssh_create_session() */
guac_common_ssh_destroy_user(user);
guac_common_ssh_destroy_user(guac_client_data->sftp_user);
return 1;
}
/* Load and expose filesystem */
guac_client_data->sftp_filesystem =
guac_common_ssh_create_sftp_filesystem(session, "/");
guac_common_ssh_create_sftp_filesystem(
guac_client_data->sftp_session, "/");
/* Abort if SFTP connection fails */
if (guac_client_data->sftp_filesystem == NULL)
if (guac_client_data->sftp_filesystem == NULL) {
guac_common_ssh_destroy_session(guac_client_data->sftp_session);
guac_common_ssh_destroy_user(guac_client_data->sftp_user);
return 1;
}
/* Set file handler for basic uploads */
client->file_handler = guac_vnc_sftp_file_handler;

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@ -38,6 +38,8 @@
#ifdef ENABLE_COMMON_SSH
#include "guac_sftp.h"
#include "guac_ssh.h"
#include "guac_ssh_user.h"
#endif
/**
@ -191,6 +193,16 @@ typedef struct vnc_guac_client_data {
guac_common_surface* default_surface;
#ifdef ENABLE_COMMON_SSH
/**
* The user and credentials used to authenticate for SFTP.
*/
guac_common_ssh_user* sftp_user;
/**
* The SSH session used for SFTP.
*/
guac_common_ssh_session* sftp_session;
/**
* The exposed filesystem object, implemented with SFTP.
*/

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@ -34,6 +34,7 @@
#ifdef ENABLE_COMMON_SSH
#include <guac_sftp.h>
#include <guac_ssh.h>
#include <guac_ssh_user.h>
#endif
#ifdef ENABLE_PULSE
@ -145,6 +146,14 @@ int vnc_guac_client_free_handler(guac_client* client) {
if (guac_client_data->sftp_filesystem)
guac_common_ssh_destroy_sftp_filesystem(guac_client_data->sftp_filesystem);
/* Free SFTP session */
if (guac_client_data->sftp_session)
guac_common_ssh_destroy_session(guac_client_data->sftp_session);
/* Free SFTP user */
if (guac_client_data->sftp_user)
guac_common_ssh_destroy_user(guac_client_data->sftp_user);
guac_common_ssh_uninit();
#endif