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Damien Millerd4a8b7e1999-10-27 13:42:43 +10001/*
2
3ssh.h
4
5Author: Tatu Ylonen <ylo@cs.hut.fi>
6
7Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
8 All rights reserved
9
10Created: Fri Mar 17 17:09:37 1995 ylo
11
12Generic header file for ssh.
13
14*/
15
Damien Miller5ce662a1999-11-11 17:57:39 +110016/* RCSID("$Id: ssh.h,v 1.10 1999/11/11 06:57:40 damien Exp $"); */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100017
18#ifndef SSH_H
19#define SSH_H
20
Damien Millerab18c411999-11-11 10:40:23 +110021#include <netinet/in.h> /* For struct sockaddr_in */
22#include <pwd.h> /* For struct pw */
Damien Miller5ce662a1999-11-11 17:57:39 +110023#include <stdarg.h> /* For va_list */
Damien Miller7f6ea021999-10-28 13:25:17 +100024
Damien Millerd4a8b7e1999-10-27 13:42:43 +100025#include "rsa.h"
26#include "cipher.h"
27
28/* The default cipher used if IDEA is not supported by the remote host.
29 It is recommended that this be one of the mandatory ciphers (DES, 3DES),
30 though that is not required. */
31#define SSH_FALLBACK_CIPHER SSH_CIPHER_3DES
32
33/* Cipher used for encrypting authentication files. */
34#define SSH_AUTHFILE_CIPHER SSH_CIPHER_3DES
35
36/* Default port number. */
37#define SSH_DEFAULT_PORT 22
38
39/* Maximum number of TCP/IP ports forwarded per direction. */
40#define SSH_MAX_FORWARDS_PER_DIRECTION 100
41
42/* Maximum number of RSA authentication identity files that can be specified
43 in configuration files or on the command line. */
44#define SSH_MAX_IDENTITY_FILES 100
45
46/* Major protocol version. Different version indicates major incompatiblity
47 that prevents communication. */
48#define PROTOCOL_MAJOR 1
49
50/* Minor protocol version. Different version indicates minor incompatibility
51 that does not prevent interoperation. */
52#define PROTOCOL_MINOR 5
53
54/* Name for the service. The port named by this service overrides the default
55 port if present. */
56#define SSH_SERVICE_NAME "ssh"
57
58#ifndef ETCDIR
59#define ETCDIR "/etc"
60#endif /* ETCDIR */
61
62#define PIDDIR "/var/run"
63
64/* System-wide file containing host keys of known hosts. This file should be
65 world-readable. */
66#define SSH_SYSTEM_HOSTFILE ETCDIR "/ssh_known_hosts"
67
68/* HOST_KEY_FILE /etc/ssh_host_key,
69 SERVER_CONFIG_FILE /etc/sshd_config,
70and HOST_CONFIG_FILE /etc/ssh_config
71are all defined in Makefile.in. Of these, ssh_host_key should be readable
72only by root, whereas ssh_config should be world-readable. */
73
74#define HOST_KEY_FILE ETCDIR "/ssh_host_key"
75#define SERVER_CONFIG_FILE ETCDIR "/sshd_config"
76#define HOST_CONFIG_FILE ETCDIR "/ssh_config"
77
Damien Miller356a0b01999-11-08 15:30:59 +110078#ifndef SSH_PROGRAM
Damien Millerd4a8b7e1999-10-27 13:42:43 +100079#define SSH_PROGRAM "/usr/bin/ssh"
Damien Miller356a0b01999-11-08 15:30:59 +110080#endif /* SSH_PROGRAM */
81
82#ifndef LOGIN_PROGRAM
83#define LOGIN_PROGRAM "/usr/bin/login"
84#endif /* LOGIN_PROGRAM */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100085
Damien Millerc7b38ce1999-11-09 10:28:04 +110086#ifndef ASKPASS_PROGRAM
87#define ASKPASS_PROGRAM "/usr/lib/ssh/ssh-askpass"
88#endif /* ASKPASS_PROGRAM */
89
Damien Millerd4a8b7e1999-10-27 13:42:43 +100090/* The process id of the daemon listening for connections is saved
91 here to make it easier to kill the correct daemon when necessary. */
Damien Millera37010e1999-10-29 09:18:29 +100092#define SSH_DAEMON_PID_FILE PIDDIR "/sshd.pid"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100093
94/* The directory in user\'s home directory in which the files reside.
95 The directory should be world-readable (though not all files are). */
96#define SSH_USER_DIR ".ssh"
97
98/* Per-user file containing host keys of known hosts. This file need
99 not be readable by anyone except the user him/herself, though this does
100 not contain anything particularly secret. */
101#define SSH_USER_HOSTFILE "~/.ssh/known_hosts"
102
103/* Name of the default file containing client-side authentication key.
104 This file should only be readable by the user him/herself. */
105#define SSH_CLIENT_IDENTITY ".ssh/identity"
106
107/* Configuration file in user\'s home directory. This file need not be
108 readable by anyone but the user him/herself, but does not contain
109 anything particularly secret. If the user\'s home directory resides
110 on an NFS volume where root is mapped to nobody, this may need to be
111 world-readable. */
112#define SSH_USER_CONFFILE ".ssh/config"
113
114/* File containing a list of those rsa keys that permit logging in as
115 this user. This file need not be
116 readable by anyone but the user him/herself, but does not contain
117 anything particularly secret. If the user\'s home directory resides
118 on an NFS volume where root is mapped to nobody, this may need to be
119 world-readable. (This file is read by the daemon which is running as
120 root.) */
121#define SSH_USER_PERMITTED_KEYS ".ssh/authorized_keys"
122
123/* Per-user and system-wide ssh "rc" files. These files are executed with
124 /bin/sh before starting the shell or command if they exist. They
125 will be passed "proto cookie" as arguments if X11 forwarding with
126 spoofing is in use. xauth will be run if neither of these exists. */
127#define SSH_USER_RC ".ssh/rc"
128#define SSH_SYSTEM_RC ETCDIR "/sshrc"
129
130/* Ssh-only version of /etc/hosts.equiv. */
131#define SSH_HOSTS_EQUIV ETCDIR "/shosts.equiv"
132
133/* Additionally, the daemon may use ~/.rhosts and /etc/hosts.equiv if
134 rhosts authentication is enabled. */
135
136/* Name of the environment variable containing the pathname of the
137 authentication socket. */
138#define SSH_AUTHSOCKET_ENV_NAME "SSH_AUTH_SOCK"
139
Damien Miller5eeedae1999-10-29 10:21:15 +1000140/* Name of the environment variable containing the pathname of the
141 authentication socket. */
142#define SSH_AGENTPID_ENV_NAME "SSH_AGENT_PID"
143
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000144/* Force host key length and server key length to differ by at least this
145 many bits. This is to make double encryption with rsaref work. */
146#define SSH_KEY_BITS_RESERVED 128
147
148/* Length of the session key in bytes. (Specified as 256 bits in the
149 protocol.) */
150#define SSH_SESSION_KEY_LENGTH 32
151
152/* Name of Kerberos service for SSH to use. */
153#define KRB4_SERVICE_NAME "rcmd"
154
155/* Authentication methods. New types can be added, but old types should not
156 be removed for compatibility. The maximum allowed value is 31. */
157#define SSH_AUTH_RHOSTS 1
158#define SSH_AUTH_RSA 2
159#define SSH_AUTH_PASSWORD 3
160#define SSH_AUTH_RHOSTS_RSA 4
161 /* 5 is TIS */
162#define SSH_AUTH_KERBEROS 6
163#define SSH_PASS_KERBEROS_TGT 7
164 /* 8 to 15 are reserved */
165#define SSH_PASS_AFS_TOKEN 21
166
167/* Protocol flags. These are bit masks. */
168#define SSH_PROTOFLAG_SCREEN_NUMBER 1 /* X11 forwarding includes screen */
169#define SSH_PROTOFLAG_HOST_IN_FWD_OPEN 2 /* forwarding opens contain host */
170
171/* Definition of message types. New values can be added, but old values
172 should not be removed or without careful consideration of the consequences
173 for compatibility. The maximum value is 254; value 255 is reserved
174 for future extension. */
175/* Message name */ /* msg code */ /* arguments */
176#define SSH_MSG_NONE 0 /* no message */
177#define SSH_MSG_DISCONNECT 1 /* cause (string) */
178#define SSH_SMSG_PUBLIC_KEY 2 /* ck,msk,srvk,hostk */
179#define SSH_CMSG_SESSION_KEY 3 /* key (BIGNUM) */
180#define SSH_CMSG_USER 4 /* user (string) */
181#define SSH_CMSG_AUTH_RHOSTS 5 /* user (string) */
182#define SSH_CMSG_AUTH_RSA 6 /* modulus (BIGNUM) */
183#define SSH_SMSG_AUTH_RSA_CHALLENGE 7 /* int (BIGNUM) */
184#define SSH_CMSG_AUTH_RSA_RESPONSE 8 /* int (BIGNUM) */
185#define SSH_CMSG_AUTH_PASSWORD 9 /* pass (string) */
186#define SSH_CMSG_REQUEST_PTY 10 /* TERM, tty modes */
187#define SSH_CMSG_WINDOW_SIZE 11 /* row,col,xpix,ypix */
188#define SSH_CMSG_EXEC_SHELL 12 /* */
189#define SSH_CMSG_EXEC_CMD 13 /* cmd (string) */
190#define SSH_SMSG_SUCCESS 14 /* */
191#define SSH_SMSG_FAILURE 15 /* */
192#define SSH_CMSG_STDIN_DATA 16 /* data (string) */
193#define SSH_SMSG_STDOUT_DATA 17 /* data (string) */
194#define SSH_SMSG_STDERR_DATA 18 /* data (string) */
195#define SSH_CMSG_EOF 19 /* */
196#define SSH_SMSG_EXITSTATUS 20 /* status (int) */
197#define SSH_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* channel (int) */
198#define SSH_MSG_CHANNEL_OPEN_FAILURE 22 /* channel (int) */
199#define SSH_MSG_CHANNEL_DATA 23 /* ch,data (int,str) */
200#define SSH_MSG_CHANNEL_CLOSE 24 /* channel (int) */
201#define SSH_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* channel (int) */
202/* SSH_CMSG_X11_REQUEST_FORWARDING 26 OBSOLETE */
203#define SSH_SMSG_X11_OPEN 27 /* channel (int) */
204#define SSH_CMSG_PORT_FORWARD_REQUEST 28 /* p,host,hp (i,s,i) */
205#define SSH_MSG_PORT_OPEN 29 /* ch,h,p (i,s,i) */
206#define SSH_CMSG_AGENT_REQUEST_FORWARDING 30 /* */
207#define SSH_SMSG_AGENT_OPEN 31 /* port (int) */
208#define SSH_MSG_IGNORE 32 /* string */
209#define SSH_CMSG_EXIT_CONFIRMATION 33 /* */
210#define SSH_CMSG_X11_REQUEST_FORWARDING 34 /* proto,data (s,s) */
211#define SSH_CMSG_AUTH_RHOSTS_RSA 35 /* user,mod (s,mpi) */
212#define SSH_MSG_DEBUG 36 /* string */
213#define SSH_CMSG_REQUEST_COMPRESSION 37 /* level 1-9 (int) */
214#define SSH_CMSG_MAX_PACKET_SIZE 38 /* size 4k-1024k (int) */
215#define SSH_CMSG_AUTH_TIS 39 /* this is proto-1.5, but we ignore TIS */
216#define SSH_SMSG_AUTH_TIS_CHALLENGE 40
217#define SSH_CMSG_AUTH_TIS_RESPONSE 41
218
219#define SSH_CMSG_AUTH_KERBEROS 42 /* (KTEXT) */
220#define SSH_SMSG_AUTH_KERBEROS_RESPONSE 43 /* (KTEXT) */
221#define SSH_CMSG_HAVE_KERBEROS_TGT 44 /* credentials (s) */
222#define SSH_CMSG_HAVE_AFS_TOKEN 65 /* token (s) */
223
224
Damien Miller5ce662a1999-11-11 17:57:39 +1100225/*------------ Definitions for logging. -----------------------*/
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000226
Damien Miller5ce662a1999-11-11 17:57:39 +1100227/* Supported syslog facilities and levels. */
228typedef enum
229{
230 SYSLOG_FACILITY_DAEMON,
231 SYSLOG_FACILITY_USER,
232 SYSLOG_FACILITY_AUTH,
233 SYSLOG_FACILITY_LOCAL0,
234 SYSLOG_FACILITY_LOCAL1,
235 SYSLOG_FACILITY_LOCAL2,
236 SYSLOG_FACILITY_LOCAL3,
237 SYSLOG_FACILITY_LOCAL4,
238 SYSLOG_FACILITY_LOCAL5,
239 SYSLOG_FACILITY_LOCAL6,
240 SYSLOG_FACILITY_LOCAL7
241} SyslogFacility;
242
243typedef enum
244{
245 SYSLOG_LEVEL_QUIET,
246 SYSLOG_LEVEL_FATAL,
247 SYSLOG_LEVEL_ERROR,
248 SYSLOG_LEVEL_INFO,
249 SYSLOG_LEVEL_CHAT,
250 SYSLOG_LEVEL_DEBUG
251} LogLevel;
252
253/* Initializes logging. */
254void log_init(char *av0, LogLevel level, SyslogFacility facility, int on_stderr);
255
256/* Logging implementation, depending on server or client */
257void do_log(LogLevel level, const char *fmt, va_list args);
258
259/* Output a message to syslog or stderr */
260void fatal(const char *fmt, ...);
261void error(const char *fmt, ...);
262void log(const char *fmt, ...);
263void chat(const char *fmt, ...);
264void debug(const char *fmt, ...);
265
266/* same as fatal() but w/o logging */
267void fatal_cleanup(void);
268
269/* Registers a cleanup function to be called by fatal()/fatal_cleanup() before exiting.
270 It is permissible to call fatal_remove_cleanup for the function itself
271 from the function. */
272void fatal_add_cleanup(void (*proc)(void *context), void *context);
273
274/* Removes a cleanup function to be called at fatal(). */
275void fatal_remove_cleanup(void (*proc)(void *context), void *context);
276
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000277
278/*------------ definitions for login.c -------------*/
279
280/* Returns the time when the user last logged in. Returns 0 if the
281 information is not available. This must be called before record_login.
282 The host from which the user logged in is stored in buf. */
283unsigned long get_last_login_time(uid_t uid, const char *logname,
284 char *buf, unsigned int bufsize);
285
286/* Records that the user has logged in. This does many things normally
287 done by login(1). */
288void record_login(int pid, const char *ttyname, const char *user, uid_t uid,
289 const char *host, struct sockaddr_in *addr);
290
291/* Records that the user has logged out. This does many thigs normally
292 done by login(1) or init. */
293void record_logout(int pid, const char *ttyname);
294
295/*------------ definitions for sshconnect.c ----------*/
296
297/* Opens a TCP/IP connection to the remote server on the given host. If
298 port is 0, the default port will be used. If anonymous is zero,
299 a privileged port will be allocated to make the connection.
300 This requires super-user privileges if anonymous is false.
301 Connection_attempts specifies the maximum number of tries, one per
302 second. This returns true on success, and zero on failure. If the
303 connection is successful, this calls packet_set_connection for the
304 connection. */
305int ssh_connect(const char *host, struct sockaddr_in *hostaddr,
306 int port, int connection_attempts,
307 int anonymous, uid_t original_real_uid,
308 const char *proxy_command);
309
310/* Starts a dialog with the server, and authenticates the current user on the
311 server. This does not need any extra privileges. The basic connection
312 to the server must already have been established before this is called.
313 If login fails, this function prints an error and never returns.
314 This initializes the random state, and leaves it initialized (it will also
315 have references from the packet module). */
Damien Miller5ce662a1999-11-11 17:57:39 +1100316
317/* for Options */
318#include "readconf.h"
319
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000320void ssh_login(int host_key_valid, RSA *host_key, const char *host,
321 struct sockaddr_in *hostaddr, Options *options,
322 uid_t original_real_uid);
323
324/*------------ Definitions for various authentication methods. -------*/
325
326/* Tries to authenticate the user using the .rhosts file. Returns true if
327 authentication succeeds. If ignore_rhosts is non-zero, this will not
328 consider .rhosts and .shosts (/etc/hosts.equiv will still be used).
329 If strict_modes is true, checks ownership and modes of .rhosts/.shosts. */
330int auth_rhosts(struct passwd *pw, const char *client_user,
331 int ignore_rhosts, int strict_modes);
332
333/* Tries to authenticate the user using the .rhosts file and the host using
334 its host key. Returns true if authentication succeeds. */
335int auth_rhosts_rsa(struct passwd *pw, const char *client_user,
336 unsigned int bits, BIGNUM *client_host_key_e,
337 BIGNUM *client_host_key_n, int ignore_rhosts,
338 int strict_modes);
339
340/* Tries to authenticate the user using password. Returns true if
341 authentication succeeds. */
342int auth_password(struct passwd *pw, const char *password);
343
344/* Performs the RSA authentication dialog with the client. This returns
345 0 if the client could not be authenticated, and 1 if authentication was
346 successful. This may exit if there is a serious protocol violation. */
347int auth_rsa(struct passwd *pw, BIGNUM *client_n, int strict_modes);
348
349/* Parses an RSA key (number of bits, e, n) from a string. Moves the pointer
350 over the key. Skips any whitespace at the beginning and at end. */
351int auth_rsa_read_key(char **cpp, unsigned int *bitsp, BIGNUM *e, BIGNUM *n);
352
353/* Returns the name of the machine at the other end of the socket. The
354 returned string should be freed by the caller. */
355char *get_remote_hostname(int socket);
356
357/* Return the canonical name of the host in the other side of the current
358 connection (as returned by packet_get_connection). The host name is
359 cached, so it is efficient to call this several times. */
360const char *get_canonical_hostname(void);
361
362/* Returns the remote IP address as an ascii string. The value need not be
363 freed by the caller. */
364const char *get_remote_ipaddr(void);
365
366/* Returns the port number of the peer of the socket. */
367int get_peer_port(int sock);
368
369/* Returns the port number of the remote host. */
370int get_remote_port(void);
371
372/* Tries to match the host name (which must be in all lowercase) against the
373 comma-separated sequence of subpatterns (each possibly preceded by ! to
374 indicate negation). Returns true if there is a positive match; zero
375 otherwise. */
376int match_hostname(const char *host, const char *pattern, unsigned int len);
377
378/* Checks whether the given host is already in the list of our known hosts.
379 Returns HOST_OK if the host is known and has the specified key,
380 HOST_NEW if the host is not known, and HOST_CHANGED if the host is known
381 but used to have a different host key. The host must be in all lowercase. */
382typedef enum { HOST_OK, HOST_NEW, HOST_CHANGED } HostStatus;
383HostStatus check_host_in_hostfile(const char *filename,
384 const char *host, unsigned int bits,
385 BIGNUM *e, BIGNUM *n,
386 BIGNUM *ke, BIGNUM *kn);
387
388/* Appends an entry to the host file. Returns false if the entry
389 could not be appended. */
390int add_host_to_hostfile(const char *filename, const char *host,
391 unsigned int bits, BIGNUM *e, BIGNUM *n);
392
393/* Performs the RSA authentication challenge-response dialog with the client,
394 and returns true (non-zero) if the client gave the correct answer to
395 our challenge; returns zero if the client gives a wrong answer. */
396int auth_rsa_challenge_dialog(unsigned int bits, BIGNUM *e, BIGNUM *n);
397
398/* Reads a passphrase from /dev/tty with echo turned off. Returns the
399 passphrase (allocated with xmalloc). Exits if EOF is encountered.
400 If from_stdin is true, the passphrase will be read from stdin instead. */
401char *read_passphrase(const char *prompt, int from_stdin);
402
403/* Saves the authentication (private) key in a file, encrypting it with
404 passphrase. The identification of the file (lowest 64 bits of n)
405 will precede the key to provide identification of the key without
406 needing a passphrase. */
407int save_private_key(const char *filename, const char *passphrase,
408 RSA *private_key, const char *comment);
409
410/* Loads the public part of the key file (public key and comment).
411 Returns 0 if an error occurred; zero if the public key was successfully
412 read. The comment of the key is returned in comment_return if it is
413 non-NULL; the caller must free the value with xfree. */
414int load_public_key(const char *filename, RSA *pub,
415 char **comment_return);
416
417/* Loads the private key from the file. Returns 0 if an error is encountered
418 (file does not exist or is not readable, or passphrase is bad).
419 This initializes the private key. The comment of the key is returned
420 in comment_return if it is non-NULL; the caller must free the value
421 with xfree. */
422int load_private_key(const char *filename, const char *passphrase,
423 RSA *private_key, char **comment_return);
424
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000425/*---------------- definitions for channels ------------------*/
426
427/* Sets specific protocol options. */
428void channel_set_options(int hostname_in_open);
429
430/* Allocate a new channel object and set its type and socket. Remote_name
431 must have been allocated with xmalloc; this will free it when the channel
432 is freed. */
433int channel_allocate(int type, int sock, char *remote_name);
434
435/* Free the channel and close its socket. */
436void channel_free(int channel);
437
438/* Add any bits relevant to channels in select bitmasks. */
439void channel_prepare_select(fd_set *readset, fd_set *writeset);
440
441/* After select, perform any appropriate operations for channels which
442 have events pending. */
443void channel_after_select(fd_set *readset, fd_set *writeset);
444
445/* If there is data to send to the connection, send some of it now. */
446void channel_output_poll(void);
447
448/* This is called when a packet of type CHANNEL_DATA has just been received.
449 The message type has already been consumed, but channel number and data
450 is still there. */
451void channel_input_data(int payload_len);
452
453/* Returns true if no channel has too much buffered data. */
454int channel_not_very_much_buffered_data(void);
455
456/* This is called after receiving CHANNEL_CLOSE. */
457void channel_input_close(void);
458
459/* This is called after receiving CHANNEL_CLOSE_CONFIRMATION. */
460void channel_input_close_confirmation(void);
461
462/* This is called after receiving CHANNEL_OPEN_CONFIRMATION. */
463void channel_input_open_confirmation(void);
464
465/* This is called after receiving CHANNEL_OPEN_FAILURE from the other side. */
466void channel_input_open_failure(void);
467
468/* This closes any sockets that are listening for connections; this removes
469 any unix domain sockets. */
470void channel_stop_listening(void);
471
472/* Closes the sockets of all channels. This is used to close extra file
473 descriptors after a fork. */
474void channel_close_all(void);
475
476/* Returns the maximum file descriptor number used by the channels. */
477int channel_max_fd(void);
478
479/* Returns true if there is still an open channel over the connection. */
480int channel_still_open(void);
481
482/* Returns a string containing a list of all open channels. The list is
483 suitable for displaying to the user. It uses crlf instead of newlines.
484 The caller should free the string with xfree. */
485char *channel_open_message(void);
486
487/* Initiate forwarding of connections to local port "port" through the secure
488 channel to host:port from remote side. This never returns if there
489 was an error. */
490void channel_request_local_forwarding(int port, const char *host,
491 int remote_port);
492
493/* Initiate forwarding of connections to port "port" on remote host through
494 the secure channel to host:port from local side. This never returns
495 if there was an error. This registers that open requests for that
496 port are permitted. */
497void channel_request_remote_forwarding(int port, const char *host,
498 int remote_port);
499
500/* Permits opening to any host/port in SSH_MSG_PORT_OPEN. This is usually
501 called by the server, because the user could connect to any port anyway,
502 and the server has no way to know but to trust the client anyway. */
503void channel_permit_all_opens(void);
504
505/* This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
506 listening for the port, and sends back a success reply (or disconnect
507 message if there was an error). This never returns if there was an
508 error. */
509void channel_input_port_forward_request(int is_root);
510
511/* This is called after receiving PORT_OPEN message. This attempts to connect
512 to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION or
513 CHANNEL_OPEN_FAILURE. */
514void channel_input_port_open(int payload_len);
515
516/* Creates a port for X11 connections, and starts listening for it.
517 Returns the display name, or NULL if an error was encountered. */
518char *x11_create_display(int screen);
519
520/* Creates an internet domain socket for listening for X11 connections.
521 Returns a suitable value for the DISPLAY variable, or NULL if an error
522 occurs. */
523char *x11_create_display_inet(int screen);
524
525/* This is called when SSH_SMSG_X11_OPEN is received. The packet contains
526 the remote channel number. We should do whatever we want, and respond
527 with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE. */
528void x11_input_open(int payload_len);
529
530/* Requests forwarding of X11 connections. This should be called on the
531 client only. */
532void x11_request_forwarding(void);
533
534/* Requests forwarding for X11 connections, with authentication spoofing.
535 This should be called in the client only. */
536void x11_request_forwarding_with_spoofing(const char *proto, const char *data);
537
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000538/* Sends a message to the server to request authentication fd forwarding. */
539void auth_request_forwarding(void);
540
541/* Returns the name of the forwarded authentication socket. Returns NULL
542 if there is no forwarded authentication socket. The returned value points
543 to a static buffer. */
544char *auth_get_socket_name(void);
545
546/* This if called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
547 This starts forwarding authentication requests. */
548void auth_input_request_forwarding(struct passwd *pw);
549
550/* This is called to process an SSH_SMSG_AGENT_OPEN message. */
551void auth_input_open_request(void);
552
553/* Returns true if the given string matches the pattern (which may contain
554 ? and * as wildcards), and zero if it does not match. */
555int match_pattern(const char *s, const char *pattern);
556
557/* Expands tildes in the file name. Returns data allocated by xmalloc.
558 Warning: this calls getpw*. */
559char *tilde_expand_filename(const char *filename, uid_t my_uid);
560
561/* Performs the interactive session. This handles data transmission between
562 the client and the program. Note that the notion of stdin, stdout, and
563 stderr in this function is sort of reversed: this function writes to
564 stdin (of the child program), and reads from stdout and stderr (of the
565 child program). */
566void server_loop(int pid, int fdin, int fdout, int fderr);
567
568/* Client side main loop for the interactive session. */
569int client_loop(int have_pty, int escape_char);
570
571/* Linked list of custom environment strings (see auth-rsa.c). */
572struct envstring {
573 struct envstring *next;
574 char *s;
575};
576
577#ifdef KRB4
578#include <krb.h>
579
580/* Performs Kerberos v4 mutual authentication with the client. This returns
581 0 if the client could not be authenticated, and 1 if authentication was
582 successful. This may exit if there is a serious protocol violation. */
583int auth_krb4(const char *server_user, KTEXT auth, char **client);
Damien Miller5ce662a1999-11-11 17:57:39 +1100584int krb4_init(uid_t uid);
585void krb4_cleanup_proc(void *ignore);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000586
587#ifdef AFS
588#include <kafs.h>
589
590/* Accept passed Kerberos v4 ticket-granting ticket and AFS tokens. */
591int auth_kerberos_tgt(struct passwd *pw, const char *string);
Damien Millerfd7c9111999-11-08 16:15:55 +1100592int auth_afs_token(struct passwd *pw, const char *token_string);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000593
594int creds_to_radix(CREDENTIALS *creds, unsigned char *buf);
595int radix_to_creds(const char *buf, CREDENTIALS *creds);
596#endif /* AFS */
597
598#endif /* KRB4 */
599
600#ifdef SKEY
601#include <skey.h>
602char *skey_fake_keyinfo(char *username);
603#endif /* SKEY */
604
605#endif /* SSH_H */