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Diffstat (limited to 'session.h')
| -rw-r--r-- | session.h | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/session.h b/session.h new file mode 100644 index 0000000..a4ad45f --- /dev/null +++ b/session.h @@ -0,0 +1,257 @@ +/* + * 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_ */ |