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/*
* Dropbear - a SSH2 server
*
* Copyright (c) 2002,2003 Matt Johnston
* All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE. */
#ifndef _SESSION_H_
#define _SESSION_H_
#include "includes.h"
#include "options.h"
#include "buffer.h"
#include "signkey.h"
#include "kex.h"
#include "auth.h"
#include "channel.h"
#include "queue.h"
#include "listener.h"
#include "packet.h"
#include "tcpfwd.h"
#include "chansession.h"
extern int sessinitdone; /* Is set to 0 somewhere */
extern int exitflag;
void common_session_init(int sock, char* remotehost);
void session_loop(void(*loophandler)());
void common_session_cleanup();
void session_identification();
/* Server */
void svr_session(int sock, int childpipe, char *remotehost, char *addrstring);
void svr_dropbear_exit(int exitcode, const char* format, va_list param);
void svr_dropbear_log(int priority, const char* format, va_list param);
/* Client */
void cli_session(int sock, char *remotehost);
void cli_session_cleanup();
void cleantext(unsigned char* dirtytext);
struct key_context {
const struct dropbear_cipher *recv_algo_crypt; /* NULL for none */
const struct dropbear_cipher *trans_algo_crypt; /* NULL for none */
const struct dropbear_hash *recv_algo_mac; /* NULL for none */
const struct dropbear_hash *trans_algo_mac; /* NULL for none */
char algo_kex;
char algo_hostkey;
char recv_algo_comp; /* compression */
char trans_algo_comp;
#ifndef DISABLE_ZLIB
z_streamp recv_zstream;
z_streamp trans_zstream;
#endif
/* actual keys */
symmetric_CBC recv_symmetric_struct;
symmetric_CBC trans_symmetric_struct;
unsigned char recvmackey[MAX_MAC_KEY];
unsigned char transmackey[MAX_MAC_KEY];
};
struct sshsession {
/* Is it a client or server? */
unsigned char isserver;
long connecttimeout; /* time to disconnect if we have a timeout (for
userauth etc), or 0 for no timeout */
int sock;
unsigned char *remotehost; /* the peer hostname */
unsigned char *remoteident;
int maxfd; /* the maximum file descriptor to check with select() */
/* Packet buffers/values etc */
buffer *writepayload; /* Unencrypted payload to write - this is used
throughout the code, as handlers fill out this
buffer with the packet to send. */
struct Queue writequeue; /* A queue of encrypted packets to send */
buffer *readbuf; /* Encrypted */
buffer *decryptreadbuf; /* Post-decryption */
buffer *payload; /* Post-decompression, the actual SSH packet */
unsigned int transseq, recvseq; /* Sequence IDs */
/* Packet-handling flags */
const packettype * packettypes; /* Packet handler mappings for this
session, see process-packet.c */
unsigned dataallowed : 1; /* whether we can send data packets or we are in
the middle of a KEX or something */
unsigned char requirenext; /* byte indicating what packet we require next,
or 0x00 for any */
unsigned char ignorenext; /* whether to ignore the next packet,
used for kex_follows stuff */
unsigned char lastpacket; /* What the last received packet type was */
/* KEX/encryption related */
struct KEXState kexstate;
struct key_context *keys;
struct key_context *newkeys;
unsigned char *session_id; /* this is the hash from the first kex */
/* The below are used temorarily during kex, are freed after use */
mp_int * dh_K; /* SSH_MSG_KEXDH_REPLY and sending SSH_MSH_NEWKEYS */
unsigned char hash[SHA1_HASH_SIZE]; /* the hash*/
buffer* kexhashbuf; /* session hash buffer calculated from various packets*/
buffer* transkexinit; /* the kexinit packet we send should be kept so we
can add it to the hash when generating keys */
algo_type*(*buf_match_algo)(buffer*buf, algo_type localalgos[],
int *goodguess); /* The function to use to choose which algorithm
to use from the ones presented by the remote
side. Is specific to the client/server mode,
hence the function-pointer callback.*/
void(*remoteclosed)(); /* A callback to handle closure of the
remote connection */
struct AuthState authstate; /* Common amongst client and server, since most
struct elements are common */
/* Channel related */
struct Channel ** channels; /* these pointers may be null */
unsigned int chansize; /* the number of Channel*s allocated for channels */
unsigned int chancount; /* the number of Channel*s in use */
const struct ChanType **chantypes; /* The valid channel types */
/* TCP forwarding - where manage listeners */
struct Listener ** listeners;
unsigned int listensize;
/* Whether to allow binding to privileged ports (<1024). This doesn't
* really belong here, but nowhere else fits nicely */
int allowprivport;
};
struct serversession {
/* Server specific options */
int childpipe; /* kept open until we successfully authenticate */
/* userauth */
struct ChildPid * childpids; /* array of mappings childpid<->channel */
unsigned int childpidsize;
/* Used to avoid a race in the exit returncode handling - see
* svr-chansession.c for details */
struct exitinfo lastexit;
/* The numeric address they connected from, used for logging */
char * addrstring;
};
typedef enum {
KEX_NOTHING,
KEXINIT_RCVD,
KEXDH_INIT_SENT,
KEXDONE,
} cli_kex_state;
typedef enum {
STATE_NOTHING,
SERVICE_AUTH_REQ_SENT,
SERVICE_AUTH_ACCEPT_RCVD,
SERVICE_CONN_REQ_SENT,
SERVICE_CONN_ACCEPT_RCVD,
USERAUTH_REQ_SENT,
USERAUTH_FAIL_RCVD,
USERAUTH_SUCCESS_RCVD,
SESSION_RUNNING,
} cli_state;
struct clientsession {
mp_int *dh_e, *dh_x; /* Used during KEX */
cli_kex_state kex_state; /* Used for progressing KEX */
cli_state state; /* Used to progress auth/channelsession etc */
unsigned donefirstkex : 1; /* Set when we set sentnewkeys, never reset */
int tty_raw_mode; /* Whether we're in raw mode (and have to clean up) */
struct termios saved_tio;
int stdincopy;
int stdinflags;
int stdoutcopy;
int stdoutflags;
int stderrcopy;
int stderrflags;
int winchange; /* Set to 1 when a windowchange signal happens */
int lastauthtype; /* either AUTH_TYPE_PUBKEY or AUTH_TYPE_PASSWORD,
for the last type of auth we tried */
#ifdef ENABLE_CLI_INTERACT_AUTH
int auth_interact_failed; /* flag whether interactive auth can still
be used */
int interact_request_received; /* flag whether we've received an
info request from the server for
interactive auth.*/
#endif
struct SignKeyList *lastprivkey;
int retval; /* What the command exit status was - we emulate it */
#if 0
TODO
struct AgentkeyList *agentkeys; /* Keys to use for public-key auth */
#endif
};
/* Global structs storing the state */
extern struct sshsession ses;
#ifdef DROPBEAR_SERVER
extern struct serversession svr_ses;
#endif /* DROPBEAR_SERVER */
#ifdef DROPBEAR_CLIENT
extern struct clientsession cli_ses;
#endif /* DROPBEAR_CLIENT */
#endif /* _SESSION_H_ */
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