diff options
Diffstat (limited to 'libssh/src/session.c')
| -rw-r--r-- | libssh/src/session.c | 888 |
1 files changed, 0 insertions, 888 deletions
diff --git a/libssh/src/session.c b/libssh/src/session.c deleted file mode 100644 index a3b19ede..00000000 --- a/libssh/src/session.c +++ /dev/null @@ -1,888 +0,0 @@ -/* - * session.c - non-networking functions - * - * This file is part of the SSH Library - * - * Copyright (c) 2005-2013 by Aris Adamantiadis - * - * The SSH Library is free software; you can redistribute it and/or modify - * it under the terms of the GNU Lesser General Public License as published by - * the Free Software Foundation; either version 2.1 of the License, or (at your - * option) any later version. - * - * The SSH Library is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY - * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public - * License for more details. - * - * You should have received a copy of the GNU Lesser General Public License - * along with the SSH Library; see the file COPYING. If not, write to - * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, - * MA 02111-1307, USA. - */ - -#include "config.h" - -#include <string.h> -#include <stdlib.h> - -#include "libssh/priv.h" -#include "libssh/libssh.h" -#include "libssh/crypto.h" -#include "libssh/server.h" -#include "libssh/socket.h" -#include "libssh/ssh2.h" -#include "libssh/agent.h" -#include "libssh/packet.h" -#include "libssh/session.h" -#include "libssh/misc.h" -#include "libssh/buffer.h" -#include "libssh/poll.h" - -#define FIRST_CHANNEL 42 // why not ? it helps to find bugs. - -/** - * @defgroup libssh_session The SSH session functions. - * @ingroup libssh - * - * Functions that manage a session. - * - * @{ - */ - -/** - * @brief Create a new ssh session. - * - * @returns A new ssh_session pointer, NULL on error. - */ -ssh_session ssh_new(void) { - ssh_session session; - char *id = NULL; - int rc; - - session = malloc(sizeof (struct ssh_session_struct)); - if (session == NULL) { - return NULL; - } - ZERO_STRUCTP(session); - - session->next_crypto = crypto_new(); - if (session->next_crypto == NULL) { - goto err; - } - - session->socket = ssh_socket_new(session); - if (session->socket == NULL) { - goto err; - } - - session->out_buffer = ssh_buffer_new(); - if (session->out_buffer == NULL) { - goto err; - } - - session->in_buffer=ssh_buffer_new(); - if (session->in_buffer == NULL) { - goto err; - } - - session->alive = 0; - session->auth_methods = 0; - ssh_set_blocking(session, 1); - session->maxchannel = FIRST_CHANNEL; - -#ifndef _WIN32 - session->agent = agent_new(session); - if (session->agent == NULL) { - goto err; - } -#endif /* _WIN32 */ - - /* OPTIONS */ - session->opts.StrictHostKeyChecking = 1; - session->opts.port = 22; - session->opts.fd = -1; - session->opts.ssh2 = 1; - session->opts.compressionlevel=7; -#ifdef WITH_SSH1 - session->opts.ssh1 = 1; -#else - session->opts.ssh1 = 0; -#endif - - session->opts.identity = ssh_list_new(); - if (session->opts.identity == NULL) { - goto err; - } - -#ifdef HAVE_ECC - id = strdup("%d/id_ecdsa"); - if (id == NULL) { - goto err; - } - rc = ssh_list_append(session->opts.identity, id); - if (rc == SSH_ERROR) { - goto err; - } -#endif - - id = strdup("%d/id_rsa"); - if (id == NULL) { - goto err; - } - rc = ssh_list_append(session->opts.identity, id); - if (rc == SSH_ERROR) { - goto err; - } - - id = strdup("%d/id_dsa"); - if (id == NULL) { - goto err; - } - rc = ssh_list_append(session->opts.identity, id); - if (rc == SSH_ERROR) { - goto err; - } - - id = strdup("%d/identity"); - if (id == NULL) { - goto err; - } - rc = ssh_list_append(session->opts.identity, id); - if (rc == SSH_ERROR) { - goto err; - } - - return session; - -err: - free(id); - ssh_free(session); - return NULL; -} - -/** - * @brief Deallocate a SSH session handle. - * - * @param[in] session The SSH session to free. - * - * @see ssh_disconnect() - * @see ssh_new() - */ -void ssh_free(ssh_session session) { - int i; - struct ssh_iterator *it; - - if (session == NULL) { - return; - } - - /* - * Delete all channels - * - * This needs the first thing we clean up cause if there is still an open - * channel we call ssh_channel_close() first. So we need a working socket - * and poll context for it. - */ - for (it = ssh_list_get_iterator(session->channels); - it != NULL; - it = ssh_list_get_iterator(session->channels)) { - ssh_channel_do_free(ssh_iterator_value(ssh_channel,it)); - ssh_list_remove(session->channels, it); - } - ssh_list_free(session->channels); - session->channels = NULL; - -#ifdef WITH_PCAP - if (session->pcap_ctx) { - ssh_pcap_context_free(session->pcap_ctx); - session->pcap_ctx = NULL; - } -#endif - - ssh_socket_free(session->socket); - session->socket = NULL; - - if (session->default_poll_ctx) { - ssh_poll_ctx_free(session->default_poll_ctx); - } - - ssh_buffer_free(session->in_buffer); - ssh_buffer_free(session->out_buffer); - session->in_buffer = session->out_buffer = NULL; - - if (session->in_hashbuf != NULL) { - ssh_buffer_free(session->in_hashbuf); - } - if (session->out_hashbuf != NULL) { - ssh_buffer_free(session->out_hashbuf); - } - - crypto_free(session->current_crypto); - crypto_free(session->next_crypto); - -#ifndef _WIN32 - agent_free(session->agent); -#endif /* _WIN32 */ - - ssh_key_free(session->srv.dsa_key); - session->srv.dsa_key = NULL; - ssh_key_free(session->srv.rsa_key); - session->srv.rsa_key = NULL; - ssh_key_free(session->srv.ecdsa_key); - session->srv.ecdsa_key = NULL; - - if (session->ssh_message_list) { - ssh_message msg; - - for (msg = ssh_list_pop_head(ssh_message, session->ssh_message_list); - msg != NULL; - msg = ssh_list_pop_head(ssh_message, session->ssh_message_list)) { - ssh_message_free(msg); - } - ssh_list_free(session->ssh_message_list); - } - - if (session->packet_callbacks) { - ssh_list_free(session->packet_callbacks); - } - - /* options */ - if (session->opts.identity) { - char *id; - - for (id = ssh_list_pop_head(char *, session->opts.identity); - id != NULL; - id = ssh_list_pop_head(char *, session->opts.identity)) { - SAFE_FREE(id); - } - ssh_list_free(session->opts.identity); - } - - SAFE_FREE(session->auth_auto_state); - SAFE_FREE(session->serverbanner); - SAFE_FREE(session->clientbanner); - SAFE_FREE(session->banner); - - SAFE_FREE(session->opts.bindaddr); - SAFE_FREE(session->opts.custombanner); - SAFE_FREE(session->opts.username); - SAFE_FREE(session->opts.host); - SAFE_FREE(session->opts.sshdir); - SAFE_FREE(session->opts.knownhosts); - SAFE_FREE(session->opts.ProxyCommand); - SAFE_FREE(session->opts.gss_server_identity); - SAFE_FREE(session->opts.gss_client_identity); - - for (i = 0; i < 10; i++) { - if (session->opts.wanted_methods[i]) { - SAFE_FREE(session->opts.wanted_methods[i]); - } - } - - /* burn connection, it could contain sensitive data */ - BURN_BUFFER(session, sizeof(struct ssh_session_struct)); - SAFE_FREE(session); -} - -/** - * @brief get the client banner - * - * @param[in] session The SSH session - * - * @return Returns the client banner string or NULL. - */ -const char* ssh_get_clientbanner(ssh_session session) { - if (session == NULL) { - return NULL; - } - - return session->clientbanner; -} - -/** - * @brief get the server banner - * - * @param[in] session The SSH session - * - * @return Returns the server banner string or NULL. - */ -const char* ssh_get_serverbanner(ssh_session session) { - if(!session) { - return NULL; - } - return session->serverbanner; -} - -/** - * @brief get the name of the input cipher for the given session. - * - * @param[in] session The SSH session. - * - * @return Returns cipher name or NULL. - */ -const char* ssh_get_cipher_in(ssh_session session) { - if ((session != NULL) && - (session->current_crypto != NULL) && - (session->current_crypto->in_cipher != NULL)) { - return session->current_crypto->in_cipher->name; - } - return NULL; -} - -/** - * @brief get the name of the output cipher for the given session. - * - * @param[in] session The SSH session. - * - * @return Returns cipher name or NULL. - */ -const char* ssh_get_cipher_out(ssh_session session) { - if ((session != NULL) && - (session->current_crypto != NULL) && - (session->current_crypto->out_cipher != NULL)) { - return session->current_crypto->out_cipher->name; - } - return NULL; -} - -/** - * @brief get the name of the input HMAC algorithm for the given session. - * - * @param[in] session The SSH session. - * - * @return Returns HMAC algorithm name or NULL if unknown. - */ -const char* ssh_get_hmac_in(ssh_session session) { - if ((session != NULL) && - (session->current_crypto != NULL)) { - return ssh_hmac_type_to_string(session->current_crypto->in_hmac); - } - return NULL; -} - -/** - * @brief get the name of the output HMAC algorithm for the given session. - * - * @param[in] session The SSH session. - * - * @return Returns HMAC algorithm name or NULL if unknown. - */ -const char* ssh_get_hmac_out(ssh_session session) { - if ((session != NULL) && - (session->current_crypto != NULL)) { - return ssh_hmac_type_to_string(session->current_crypto->out_hmac); - } - return NULL; -} - -/** - * @brief Disconnect impolitely from a remote host by closing the socket. - * - * Suitable if you forked and want to destroy this session. - * - * @param[in] session The SSH session to disconnect. - */ -void ssh_silent_disconnect(ssh_session session) { - if (session == NULL) { - return; - } - - ssh_socket_close(session->socket); - session->alive = 0; - ssh_disconnect(session); -} - -/** - * @brief Set the session in blocking/nonblocking mode. - * - * @param[in] session The ssh session to change. - * - * @param[in] blocking Zero for nonblocking mode. - */ -void ssh_set_blocking(ssh_session session, int blocking) { - if (session == NULL) { - return; - } - session->flags &= ~SSH_SESSION_FLAG_BLOCKING; - session->flags |= blocking ? SSH_SESSION_FLAG_BLOCKING : 0; -} - -/** - * @brief Return the blocking mode of libssh - * @param[in] session The SSH session - * @returns 0 if the session is nonblocking, - * @returns 1 if the functions may block. - */ -int ssh_is_blocking(ssh_session session){ - return (session->flags&SSH_SESSION_FLAG_BLOCKING) ? 1 : 0; -} - -/* Waits until the output socket is empty */ -static int ssh_flush_termination(void *c){ - ssh_session session = c; - if (ssh_socket_buffered_write_bytes(session->socket) == 0 || - session->session_state == SSH_SESSION_STATE_ERROR) - return 1; - else - return 0; -} - -/** - * @brief Blocking flush of the outgoing buffer - * @param[in] session The SSH session - * @param[in] timeout Set an upper limit on the time for which this function - * will block, in milliseconds. Specifying -1 - * means an infinite timeout. This parameter is passed to - * the poll() function. - * @returns SSH_OK on success, SSH_AGAIN if timeout occurred, - * SSH_ERROR otherwise. - */ - -int ssh_blocking_flush(ssh_session session, int timeout){ - int rc; - if (session == NULL) { - return SSH_ERROR; - } - - rc = ssh_handle_packets_termination(session, timeout, - ssh_flush_termination, session); - if (rc == SSH_ERROR) { - return rc; - } - if (!ssh_flush_termination(session)) { - rc = SSH_AGAIN; - } - - return rc; -} - -/** - * @brief Check if we are connected. - * - * @param[in] session The session to check if it is connected. - * - * @return 1 if we are connected, 0 if not. - */ -int ssh_is_connected(ssh_session session) { - if (session == NULL) { - return 0; - } - - return session->alive; -} - -/** - * @brief Get the fd of a connection. - * - * In case you'd need the file descriptor of the connection to the server/client. - * - * @param[in] session The ssh session to use. - * - * @return The file descriptor of the connection, or -1 if it is - * not connected - */ -socket_t ssh_get_fd(ssh_session session) { - if (session == NULL) { - return -1; - } - - return ssh_socket_get_fd_in(session->socket); -} - -/** - * @brief Tell the session it has data to read on the file descriptor without - * blocking. - * - * @param[in] session The ssh session to use. - */ -void ssh_set_fd_toread(ssh_session session) { - if (session == NULL) { - return; - } - - ssh_socket_set_read_wontblock(session->socket); -} - -/** - * @brief Tell the session it may write to the file descriptor without blocking. - * - * @param[in] session The ssh session to use. - */ -void ssh_set_fd_towrite(ssh_session session) { - if (session == NULL) { - return; - } - - ssh_socket_set_write_wontblock(session->socket); -} - -/** - * @brief Tell the session it has an exception to catch on the file descriptor. - * - * \param[in] session The ssh session to use. - */ -void ssh_set_fd_except(ssh_session session) { - if (session == NULL) { - return; - } - - ssh_socket_set_except(session->socket); -} - -/** - * @internal - * - * @brief Poll the current session for an event and call the appropriate - * callbacks. This function will not loop until the timeout is expired. - * - * This will block until one event happens. - * - * @param[in] session The session handle to use. - * - * @param[in] timeout Set an upper limit on the time for which this function - * will block, in milliseconds. Specifying SSH_TIMEOUT_INFINITE - * (-1) means an infinite timeout. - * Specifying SSH_TIMEOUT_USER means to use the timeout - * specified in options. 0 means poll will return immediately. - * This parameter is passed to the poll() function. - * - * @return SSH_OK on success, SSH_ERROR otherwise. - */ -int ssh_handle_packets(ssh_session session, int timeout) { - ssh_poll_handle spoll_in,spoll_out; - ssh_poll_ctx ctx; - int tm = timeout; - int rc; - - if (session == NULL || session->socket == NULL) { - return SSH_ERROR; - } - - spoll_in = ssh_socket_get_poll_handle_in(session->socket); - spoll_out = ssh_socket_get_poll_handle_out(session->socket); - ssh_poll_add_events(spoll_in, POLLIN); - ctx = ssh_poll_get_ctx(spoll_in); - - if (!ctx) { - ctx = ssh_poll_get_default_ctx(session); - ssh_poll_ctx_add(ctx, spoll_in); - if (spoll_in != spoll_out) { - ssh_poll_ctx_add(ctx, spoll_out); - } - } - - if (timeout == SSH_TIMEOUT_USER) { - if (ssh_is_blocking(session)) - tm = ssh_make_milliseconds(session->opts.timeout, - session->opts.timeout_usec); - else - tm = 0; - } - rc = ssh_poll_ctx_dopoll(ctx, tm); - if (rc == SSH_ERROR) { - session->session_state = SSH_SESSION_STATE_ERROR; - } - - return rc; -} - -/** - * @internal - * - * @brief Poll the current session for an event and call the appropriate - * callbacks. - * - * This will block until termination function returns true, or timeout expired. - * - * @param[in] session The session handle to use. - * - * @param[in] timeout Set an upper limit on the time for which this function - * will block, in milliseconds. Specifying SSH_TIMEOUT_INFINITE - * (-1) means an infinite timeout. - * Specifying SSH_TIMEOUT_USER means to use the timeout - * specified in options. 0 means poll will return immediately. - * SSH_TIMEOUT_DEFAULT uses blocking parameters of the session. - * This parameter is passed to the poll() function. - * - * @param[in] fct Termination function to be used to determine if it is - * possible to stop polling. - * @param[in] user User parameter to be passed to fct termination function. - * @return SSH_OK on success, SSH_ERROR otherwise. - */ -int ssh_handle_packets_termination(ssh_session session, - int timeout, - ssh_termination_function fct, - void *user) -{ - struct ssh_timestamp ts; - int ret = SSH_OK; - int tm; - - if (timeout == SSH_TIMEOUT_USER) { - if (ssh_is_blocking(session)) { - timeout = ssh_make_milliseconds(session->opts.timeout, - session->opts.timeout_usec); - } else { - timeout = SSH_TIMEOUT_NONBLOCKING; - } - } else if (timeout == SSH_TIMEOUT_DEFAULT) { - if (ssh_is_blocking(session)) { - timeout = SSH_TIMEOUT_INFINITE; - } else { - timeout = SSH_TIMEOUT_NONBLOCKING; - } - } - - /* avoid unnecessary syscall for the SSH_TIMEOUT_NONBLOCKING case */ - if (timeout != SSH_TIMEOUT_NONBLOCKING) { - ssh_timestamp_init(&ts); - } - - tm = timeout; - while(!fct(user)) { - ret = ssh_handle_packets(session, tm); - if (ret == SSH_ERROR) { - break; - } - if (ssh_timeout_elapsed(&ts,timeout)) { - ret = fct(user) ? SSH_OK : SSH_AGAIN; - break; - } - - tm = ssh_timeout_update(&ts, timeout); - } - - return ret; -} - -/** - * @brief Get session status - * - * @param session The ssh session to use. - * - * @returns A bitmask including SSH_CLOSED, SSH_READ_PENDING, SSH_WRITE_PENDING - * or SSH_CLOSED_ERROR which respectively means the session is closed, - * has data to read on the connection socket and session was closed - * due to an error. - */ -int ssh_get_status(ssh_session session) { - int socketstate; - int r = 0; - - if (session == NULL) { - return 0; - } - - socketstate = ssh_socket_get_status(session->socket); - - if (session->session_state == SSH_SESSION_STATE_DISCONNECTED) { - r |= SSH_CLOSED; - } - if (socketstate & SSH_READ_PENDING) { - r |= SSH_READ_PENDING; - } - if (socketstate & SSH_WRITE_PENDING) { - r |= SSH_WRITE_PENDING; - } - if ((session->session_state == SSH_SESSION_STATE_DISCONNECTED && - (socketstate & SSH_CLOSED_ERROR)) || - session->session_state == SSH_SESSION_STATE_ERROR) { - r |= SSH_CLOSED_ERROR; - } - - return r; -} - -/** - * @brief Get poll flags for an external mainloop - * - * @param session The ssh session to use. - * - * @returns A bitmask including SSH_READ_PENDING or SSH_WRITE_PENDING. - * For SSH_READ_PENDING, your invocation of poll() should include - * POLLIN. For SSH_WRITE_PENDING, your invocation of poll() should - * include POLLOUT. - */ -int ssh_get_poll_flags(ssh_session session) -{ - if (session == NULL) { - return 0; - } - - return ssh_socket_get_poll_flags (session->socket); -} - -/** - * @brief Get the disconnect message from the server. - * - * @param[in] session The ssh session to use. - * - * @return The message sent by the server along with the - * disconnect, or NULL in which case the reason of the - * disconnect may be found with ssh_get_error. - * - * @see ssh_get_error() - */ -const char *ssh_get_disconnect_message(ssh_session session) { - if (session == NULL) { - return NULL; - } - - if (session->session_state != SSH_SESSION_STATE_DISCONNECTED) { - ssh_set_error(session, SSH_REQUEST_DENIED, - "Connection not closed yet"); - } else if(!session->discon_msg) { - ssh_set_error(session, SSH_FATAL, - "Connection correctly closed but no disconnect message"); - } else { - return session->discon_msg; - } - - return NULL; -} - -/** - * @brief Get the protocol version of the session. - * - * @param session The ssh session to use. - * - * @return 1 or 2, for ssh1 or ssh2, < 0 on error. - */ -int ssh_get_version(ssh_session session) { - if (session == NULL) { - return -1; - } - - return session->version; -} - -/** - * @internal - * @brief Callback to be called when the socket received an exception code. - * @param user is a pointer to session - */ -void ssh_socket_exception_callback(int code, int errno_code, void *user){ - ssh_session session=(ssh_session)user; - - SSH_LOG(SSH_LOG_RARE,"Socket exception callback: %d (%d)",code, errno_code); - session->session_state = SSH_SESSION_STATE_ERROR; - if (errno_code == 0 && code == SSH_SOCKET_EXCEPTION_EOF) { - ssh_set_error(session, SSH_FATAL, "Socket error: disconnected"); - } else { - ssh_set_error(session, SSH_FATAL, "Socket error: %s", strerror(errno_code)); - } - - session->ssh_connection_callback(session); -} - -/** - * @brief Send a message that should be ignored - * - * @param[in] session The SSH session - * @param[in] data Data to be sent - * - * @return SSH_OK on success, SSH_ERROR otherwise. - */ -int ssh_send_ignore (ssh_session session, const char *data) { - int rc; - - if (ssh_socket_is_open(session->socket)) { - - rc = ssh_buffer_pack(session->out_buffer, - "bs", - SSH2_MSG_IGNORE, - data); - if (rc != SSH_OK){ - ssh_set_error_oom(session); - goto error; - } - packet_send(session); - ssh_handle_packets(session, 0); - } - - return SSH_OK; - -error: - ssh_buffer_reinit(session->out_buffer); - return SSH_ERROR; -} - -/** - * @brief Send a debug message - * - * @param[in] session The SSH session - * @param[in] message Data to be sent - * @param[in] always_display Message SHOULD be displayed by the server. It - * SHOULD NOT be displayed unless debugging - * information has been explicitly requested. - * - * @return SSH_OK on success, SSH_ERROR otherwise. - */ -int ssh_send_debug (ssh_session session, const char *message, int always_display) { - int rc; - - if (ssh_socket_is_open(session->socket)) { - rc = ssh_buffer_pack(session->out_buffer, - "bbsd", - SSH2_MSG_DEBUG, - always_display != 0 ? 1 : 0, - message, - 0); /* empty language tag */ - if (rc != SSH_OK) { - ssh_set_error_oom(session); - goto error; - } - packet_send(session); - ssh_handle_packets(session, 0); - } - - return SSH_OK; - -error: - ssh_buffer_reinit(session->out_buffer); - return SSH_ERROR; -} - - /** - * @brief Set the session data counters. - * - * This functions sets the counter structures to be used to calculate data - * which comes in and goes out through the session at different levels. - * - * @code - * struct ssh_counter_struct scounter = { - * .in_bytes = 0, - * .out_bytes = 0, - * .in_packets = 0, - * .out_packets = 0 - * }; - * - * struct ssh_counter_struct rcounter = { - * .in_bytes = 0, - * .out_bytes = 0, - * .in_packets = 0, - * .out_packets = 0 - * }; - * - * ssh_set_counters(session, &scounter, &rcounter); - * @endcode - * - * @param[in] session The SSH session. - * - * @param[in] scounter Counter for byte data handled by the session sockets. - * - * @param[in] rcounter Counter for byte and packet data handled by the session, - * prior compression and SSH overhead. - */ -void ssh_set_counters(ssh_session session, ssh_counter scounter, - ssh_counter rcounter) { - if (session != NULL) { - session->socket_counter = scounter; - session->raw_counter = rcounter; - } -} - -/** @} */ - -/* vim: set ts=4 sw=4 et cindent: */ |