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Damien Millerd4a8b7e1999-10-27 13:42:43 +10001/*
Damien Miller95def091999-11-25 00:26:21 +11002 *
3 * ssh.h
4 *
5 * Author: Tatu Ylonen <ylo@cs.hut.fi>
6 *
7 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
8 * All rights reserved
9 *
10 * Created: Fri Mar 17 17:09:37 1995 ylo
11 *
12 * Generic header file for ssh.
13 *
14 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100015
Damien Miller365199d1999-12-22 00:12:38 +110016/* RCSID("$Id: ssh.h,v 1.21 1999/12/21 13:12:39 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 Miller365199d1999-12-22 00:12:38 +110024#ifdef HAVE_SYS_SELECT_H
25# include <sys/select.h>
26#endif
Damien Millerd4a8b7e1999-10-27 13:42:43 +100027#include "rsa.h"
28#include "cipher.h"
29
Damien Miller5428f641999-11-25 11:54:57 +110030/*
31 * The default cipher used if IDEA is not supported by the remote host. It is
32 * recommended that this be one of the mandatory ciphers (DES, 3DES), though
33 * that is not required.
34 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100035#define SSH_FALLBACK_CIPHER SSH_CIPHER_3DES
36
37/* Cipher used for encrypting authentication files. */
38#define SSH_AUTHFILE_CIPHER SSH_CIPHER_3DES
39
40/* Default port number. */
41#define SSH_DEFAULT_PORT 22
42
43/* Maximum number of TCP/IP ports forwarded per direction. */
44#define SSH_MAX_FORWARDS_PER_DIRECTION 100
45
Damien Miller5428f641999-11-25 11:54:57 +110046/*
47 * Maximum number of RSA authentication identity files that can be specified
48 * in configuration files or on the command line.
49 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100050#define SSH_MAX_IDENTITY_FILES 100
51
Damien Miller5428f641999-11-25 11:54:57 +110052/*
53 * Major protocol version. Different version indicates major incompatiblity
54 * that prevents communication.
55 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100056#define PROTOCOL_MAJOR 1
57
Damien Miller5428f641999-11-25 11:54:57 +110058/*
59 * Minor protocol version. Different version indicates minor incompatibility
60 * that does not prevent interoperation.
61 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100062#define PROTOCOL_MINOR 5
63
Damien Miller5428f641999-11-25 11:54:57 +110064/*
65 * Name for the service. The port named by this service overrides the
66 * default port if present.
67 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100068#define SSH_SERVICE_NAME "ssh"
69
70#ifndef ETCDIR
71#define ETCDIR "/etc"
72#endif /* ETCDIR */
73
Damien Miller95def091999-11-25 00:26:21 +110074#ifndef PIDDIR
Damien Millerd4a8b7e1999-10-27 13:42:43 +100075#define PIDDIR "/var/run"
Damien Miller95def091999-11-25 00:26:21 +110076#endif /* PIDDIR */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100077
Damien Miller5428f641999-11-25 11:54:57 +110078/*
79 * System-wide file containing host keys of known hosts. This file should be
80 * world-readable.
81 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100082#define SSH_SYSTEM_HOSTFILE ETCDIR "/ssh_known_hosts"
83
Damien Miller5428f641999-11-25 11:54:57 +110084/*
85 * Of these, ssh_host_key must be readable only by root, whereas ssh_config
86 * should be world-readable.
87 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100088#define HOST_KEY_FILE ETCDIR "/ssh_host_key"
89#define SERVER_CONFIG_FILE ETCDIR "/sshd_config"
90#define HOST_CONFIG_FILE ETCDIR "/ssh_config"
91
Damien Miller356a0b01999-11-08 15:30:59 +110092#ifndef SSH_PROGRAM
Damien Miller95def091999-11-25 00:26:21 +110093#define SSH_PROGRAM "/usr/bin/ssh"
Damien Miller356a0b01999-11-08 15:30:59 +110094#endif /* SSH_PROGRAM */
95
96#ifndef LOGIN_PROGRAM
Damien Miller95def091999-11-25 00:26:21 +110097#define LOGIN_PROGRAM "/usr/bin/login"
Damien Miller356a0b01999-11-08 15:30:59 +110098#endif /* LOGIN_PROGRAM */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100099
Damien Millerc7b38ce1999-11-09 10:28:04 +1100100#ifndef ASKPASS_PROGRAM
Damien Miller95def091999-11-25 00:26:21 +1100101#define ASKPASS_PROGRAM "/usr/lib/ssh/ssh-askpass"
Damien Millerc7b38ce1999-11-09 10:28:04 +1100102#endif /* ASKPASS_PROGRAM */
103
Damien Miller5428f641999-11-25 11:54:57 +1100104/*
105 * The process id of the daemon listening for connections is saved here to
106 * make it easier to kill the correct daemon when necessary.
107 */
Damien Millera37010e1999-10-29 09:18:29 +1000108#define SSH_DAEMON_PID_FILE PIDDIR "/sshd.pid"
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000109
Damien Miller5428f641999-11-25 11:54:57 +1100110/*
111 * The directory in user\'s home directory in which the files reside. The
112 * directory should be world-readable (though not all files are).
113 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000114#define SSH_USER_DIR ".ssh"
115
Damien Miller5428f641999-11-25 11:54:57 +1100116/*
117 * Per-user file containing host keys of known hosts. This file need not be
118 * readable by anyone except the user him/herself, though this does not
119 * contain anything particularly secret.
120 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000121#define SSH_USER_HOSTFILE "~/.ssh/known_hosts"
122
Damien Miller5428f641999-11-25 11:54:57 +1100123/*
124 * Name of the default file containing client-side authentication key. This
125 * file should only be readable by the user him/herself.
126 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000127#define SSH_CLIENT_IDENTITY ".ssh/identity"
128
Damien Miller5428f641999-11-25 11:54:57 +1100129/*
130 * Configuration file in user\'s home directory. This file need not be
131 * readable by anyone but the user him/herself, but does not contain anything
132 * particularly secret. If the user\'s home directory resides on an NFS
133 * volume where root is mapped to nobody, this may need to be world-readable.
134 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000135#define SSH_USER_CONFFILE ".ssh/config"
136
Damien Miller5428f641999-11-25 11:54:57 +1100137/*
138 * File containing a list of those rsa keys that permit logging in as this
139 * user. This file need not be readable by anyone but the user him/herself,
140 * but does not contain anything particularly secret. If the user\'s home
141 * directory resides on an NFS volume where root is mapped to nobody, this
142 * may need to be world-readable. (This file is read by the daemon which is
143 * running as root.)
144 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000145#define SSH_USER_PERMITTED_KEYS ".ssh/authorized_keys"
146
Damien Miller5428f641999-11-25 11:54:57 +1100147/*
148 * Per-user and system-wide ssh "rc" files. These files are executed with
149 * /bin/sh before starting the shell or command if they exist. They will be
150 * passed "proto cookie" as arguments if X11 forwarding with spoofing is in
151 * use. xauth will be run if neither of these exists.
152 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000153#define SSH_USER_RC ".ssh/rc"
154#define SSH_SYSTEM_RC ETCDIR "/sshrc"
155
Damien Miller5428f641999-11-25 11:54:57 +1100156/*
157 * Ssh-only version of /etc/hosts.equiv. Additionally, the daemon may use
158 * ~/.rhosts and /etc/hosts.equiv if rhosts authentication is enabled.
159 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000160#define SSH_HOSTS_EQUIV ETCDIR "/shosts.equiv"
161
Damien Miller5428f641999-11-25 11:54:57 +1100162/*
163 * Name of the environment variable containing the pathname of the
164 * authentication socket.
165 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000166#define SSH_AUTHSOCKET_ENV_NAME "SSH_AUTH_SOCK"
167
Damien Miller5428f641999-11-25 11:54:57 +1100168/*
169 * Name of the environment variable containing the pathname of the
170 * authentication socket.
171 */
Damien Miller32265091999-11-12 11:33:04 +1100172#define SSH_AGENTPID_ENV_NAME "SSH_AGENT_PID"
Damien Miller5eeedae1999-10-29 10:21:15 +1000173
Damien Miller5428f641999-11-25 11:54:57 +1100174/*
Damien Milleraae6c611999-12-06 11:47:28 +1100175 * Default path to ssh-askpass used by ssh-add,
176 * environment variable for overwriting the default location
177 */
Damien Miller3bc14dd1999-12-07 14:54:53 +1100178#ifndef SSH_ASKPASS_DEFAULT
179# define SSH_ASKPASS_DEFAULT "/usr/X11R6/bin/ssh-askpass"
180#endif
Damien Milleraae6c611999-12-06 11:47:28 +1100181#define SSH_ASKPASS_ENV "SSH_ASKPASS"
182
183/*
Damien Miller5428f641999-11-25 11:54:57 +1100184 * Force host key length and server key length to differ by at least this
185 * many bits. This is to make double encryption with rsaref work.
186 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000187#define SSH_KEY_BITS_RESERVED 128
188
Damien Miller5428f641999-11-25 11:54:57 +1100189/*
190 * Length of the session key in bytes. (Specified as 256 bits in the
191 * protocol.)
192 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000193#define SSH_SESSION_KEY_LENGTH 32
194
195/* Name of Kerberos service for SSH to use. */
196#define KRB4_SERVICE_NAME "rcmd"
197
Damien Miller5428f641999-11-25 11:54:57 +1100198/*
199 * Authentication methods. New types can be added, but old types should not
200 * be removed for compatibility. The maximum allowed value is 31.
201 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000202#define SSH_AUTH_RHOSTS 1
203#define SSH_AUTH_RSA 2
204#define SSH_AUTH_PASSWORD 3
205#define SSH_AUTH_RHOSTS_RSA 4
Damien Miller95def091999-11-25 00:26:21 +1100206#define SSH_AUTH_TIS 5
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000207#define SSH_AUTH_KERBEROS 6
208#define SSH_PASS_KERBEROS_TGT 7
Damien Miller5428f641999-11-25 11:54:57 +1100209 /* 8 to 15 are reserved */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000210#define SSH_PASS_AFS_TOKEN 21
211
212/* Protocol flags. These are bit masks. */
Damien Miller5428f641999-11-25 11:54:57 +1100213#define SSH_PROTOFLAG_SCREEN_NUMBER 1 /* X11 forwarding includes screen */
214#define SSH_PROTOFLAG_HOST_IN_FWD_OPEN 2 /* forwarding opens contain host */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000215
Damien Miller5428f641999-11-25 11:54:57 +1100216/*
217 * Definition of message types. New values can be added, but old values
218 * should not be removed or without careful consideration of the consequences
219 * for compatibility. The maximum value is 254; value 255 is reserved for
220 * future extension.
221 */
222/* Message name */ /* msg code */ /* arguments */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000223#define SSH_MSG_NONE 0 /* no message */
224#define SSH_MSG_DISCONNECT 1 /* cause (string) */
225#define SSH_SMSG_PUBLIC_KEY 2 /* ck,msk,srvk,hostk */
226#define SSH_CMSG_SESSION_KEY 3 /* key (BIGNUM) */
227#define SSH_CMSG_USER 4 /* user (string) */
228#define SSH_CMSG_AUTH_RHOSTS 5 /* user (string) */
229#define SSH_CMSG_AUTH_RSA 6 /* modulus (BIGNUM) */
230#define SSH_SMSG_AUTH_RSA_CHALLENGE 7 /* int (BIGNUM) */
231#define SSH_CMSG_AUTH_RSA_RESPONSE 8 /* int (BIGNUM) */
232#define SSH_CMSG_AUTH_PASSWORD 9 /* pass (string) */
233#define SSH_CMSG_REQUEST_PTY 10 /* TERM, tty modes */
234#define SSH_CMSG_WINDOW_SIZE 11 /* row,col,xpix,ypix */
235#define SSH_CMSG_EXEC_SHELL 12 /* */
236#define SSH_CMSG_EXEC_CMD 13 /* cmd (string) */
237#define SSH_SMSG_SUCCESS 14 /* */
238#define SSH_SMSG_FAILURE 15 /* */
239#define SSH_CMSG_STDIN_DATA 16 /* data (string) */
240#define SSH_SMSG_STDOUT_DATA 17 /* data (string) */
241#define SSH_SMSG_STDERR_DATA 18 /* data (string) */
242#define SSH_CMSG_EOF 19 /* */
243#define SSH_SMSG_EXITSTATUS 20 /* status (int) */
244#define SSH_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* channel (int) */
245#define SSH_MSG_CHANNEL_OPEN_FAILURE 22 /* channel (int) */
246#define SSH_MSG_CHANNEL_DATA 23 /* ch,data (int,str) */
247#define SSH_MSG_CHANNEL_CLOSE 24 /* channel (int) */
248#define SSH_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* channel (int) */
249/* SSH_CMSG_X11_REQUEST_FORWARDING 26 OBSOLETE */
250#define SSH_SMSG_X11_OPEN 27 /* channel (int) */
251#define SSH_CMSG_PORT_FORWARD_REQUEST 28 /* p,host,hp (i,s,i) */
252#define SSH_MSG_PORT_OPEN 29 /* ch,h,p (i,s,i) */
253#define SSH_CMSG_AGENT_REQUEST_FORWARDING 30 /* */
254#define SSH_SMSG_AGENT_OPEN 31 /* port (int) */
255#define SSH_MSG_IGNORE 32 /* string */
256#define SSH_CMSG_EXIT_CONFIRMATION 33 /* */
257#define SSH_CMSG_X11_REQUEST_FORWARDING 34 /* proto,data (s,s) */
258#define SSH_CMSG_AUTH_RHOSTS_RSA 35 /* user,mod (s,mpi) */
259#define SSH_MSG_DEBUG 36 /* string */
260#define SSH_CMSG_REQUEST_COMPRESSION 37 /* level 1-9 (int) */
261#define SSH_CMSG_MAX_PACKET_SIZE 38 /* size 4k-1024k (int) */
Damien Miller95def091999-11-25 00:26:21 +1100262#define SSH_CMSG_AUTH_TIS 39 /* we use this for s/key */
263#define SSH_SMSG_AUTH_TIS_CHALLENGE 40 /* challenge (string) */
264#define SSH_CMSG_AUTH_TIS_RESPONSE 41 /* response (string) */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000265#define SSH_CMSG_AUTH_KERBEROS 42 /* (KTEXT) */
266#define SSH_SMSG_AUTH_KERBEROS_RESPONSE 43 /* (KTEXT) */
267#define SSH_CMSG_HAVE_KERBEROS_TGT 44 /* credentials (s) */
268#define SSH_CMSG_HAVE_AFS_TOKEN 65 /* token (s) */
269
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000270/*------------ definitions for login.c -------------*/
271
Damien Miller5428f641999-11-25 11:54:57 +1100272/*
273 * Returns the time when the user last logged in. Returns 0 if the
274 * information is not available. This must be called before record_login.
275 * The host from which the user logged in is stored in buf.
276 */
Damien Miller95def091999-11-25 00:26:21 +1100277unsigned long
278get_last_login_time(uid_t uid, const char *logname,
279 char *buf, unsigned int bufsize);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000280
Damien Miller5428f641999-11-25 11:54:57 +1100281/*
282 * Records that the user has logged in. This does many things normally done
283 * by login(1).
284 */
Damien Miller95def091999-11-25 00:26:21 +1100285void
286record_login(int pid, const char *ttyname, const char *user, uid_t uid,
287 const char *host, struct sockaddr_in * addr);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000288
Damien Miller5428f641999-11-25 11:54:57 +1100289/*
290 * Records that the user has logged out. This does many thigs normally done
291 * by login(1) or init.
292 */
Damien Miller95def091999-11-25 00:26:21 +1100293void record_logout(int pid, const char *ttyname);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000294
295/*------------ definitions for sshconnect.c ----------*/
296
Damien Miller5428f641999-11-25 11:54:57 +1100297/*
298 * Opens a TCP/IP connection to the remote server on the given host. If port
299 * is 0, the default port will be used. If anonymous is zero, a privileged
300 * port will be allocated to make the connection. This requires super-user
301 * privileges if anonymous is false. Connection_attempts specifies the
302 * maximum number of tries, one per second. This returns true on success,
303 * and zero on failure. If the connection is successful, this calls
304 * packet_set_connection for the connection.
305 */
Damien Miller95def091999-11-25 00:26:21 +1100306int
307ssh_connect(const char *host, struct sockaddr_in * hostaddr,
Damien Milleraae6c611999-12-06 11:47:28 +1100308 u_short port, int connection_attempts,
Damien Miller95def091999-11-25 00:26:21 +1100309 int anonymous, uid_t original_real_uid,
310 const char *proxy_command);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000311
Damien Miller5428f641999-11-25 11:54:57 +1100312/*
313 * Starts a dialog with the server, and authenticates the current user on the
314 * server. This does not need any extra privileges. The basic connection to
315 * the server must already have been established before this is called. If
316 * login fails, this function prints an error and never returns. This
317 * initializes the random state, and leaves it initialized (it will also have
318 * references from the packet module).
319 */
Damien Miller5ce662a1999-11-11 17:57:39 +1100320
Damien Miller95def091999-11-25 00:26:21 +1100321void
322ssh_login(int host_key_valid, RSA * host_key, const char *host,
323 struct sockaddr_in * hostaddr, uid_t original_real_uid);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000324
325/*------------ Definitions for various authentication methods. -------*/
326
Damien Miller5428f641999-11-25 11:54:57 +1100327/*
328 * Tries to authenticate the user using the .rhosts file. Returns true if
329 * authentication succeeds. If ignore_rhosts is non-zero, this will not
330 * consider .rhosts and .shosts (/etc/hosts.equiv will still be used).
331 */
Damien Miller95def091999-11-25 00:26:21 +1100332int auth_rhosts(struct passwd * pw, const char *client_user);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000333
Damien Miller5428f641999-11-25 11:54:57 +1100334/*
335 * Tries to authenticate the user using the .rhosts file and the host using
336 * its host key. Returns true if authentication succeeds.
337 */
Damien Miller95def091999-11-25 00:26:21 +1100338int
339auth_rhosts_rsa(struct passwd * pw, const char *client_user,
340 BIGNUM * client_host_key_e, BIGNUM * client_host_key_n);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000341
Damien Miller5428f641999-11-25 11:54:57 +1100342/*
343 * Tries to authenticate the user using password. Returns true if
344 * authentication succeeds.
345 */
Damien Miller95def091999-11-25 00:26:21 +1100346int auth_password(struct passwd * pw, const char *password);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000347
Damien Miller5428f641999-11-25 11:54:57 +1100348/*
349 * Performs the RSA authentication dialog with the client. This returns 0 if
350 * the client could not be authenticated, and 1 if authentication was
351 * successful. This may exit if there is a serious protocol violation.
352 */
Damien Miller95def091999-11-25 00:26:21 +1100353int auth_rsa(struct passwd * pw, BIGNUM * client_n);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000354
Damien Miller5428f641999-11-25 11:54:57 +1100355/*
356 * Parses an RSA key (number of bits, e, n) from a string. Moves the pointer
357 * over the key. Skips any whitespace at the beginning and at end.
358 */
Damien Miller95def091999-11-25 00:26:21 +1100359int auth_rsa_read_key(char **cpp, unsigned int *bitsp, BIGNUM * e, BIGNUM * n);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000360
Damien Miller5428f641999-11-25 11:54:57 +1100361/*
362 * Returns the name of the machine at the other end of the socket. The
363 * returned string should be freed by the caller.
364 */
Damien Miller95def091999-11-25 00:26:21 +1100365char *get_remote_hostname(int socket);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000366
Damien Miller5428f641999-11-25 11:54:57 +1100367/*
368 * Return the canonical name of the host in the other side of the current
369 * connection (as returned by packet_get_connection). The host name is
370 * cached, so it is efficient to call this several times.
371 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000372const char *get_canonical_hostname(void);
373
Damien Miller5428f641999-11-25 11:54:57 +1100374/*
375 * Returns the remote IP address as an ascii string. The value need not be
376 * freed by the caller.
377 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000378const char *get_remote_ipaddr(void);
379
380/* Returns the port number of the peer of the socket. */
Damien Miller95def091999-11-25 00:26:21 +1100381int get_peer_port(int sock);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000382
383/* Returns the port number of the remote host. */
Damien Miller95def091999-11-25 00:26:21 +1100384int get_remote_port(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000385
Damien Miller5428f641999-11-25 11:54:57 +1100386/*
387 * Tries to match the host name (which must be in all lowercase) against the
388 * comma-separated sequence of subpatterns (each possibly preceded by ! to
389 * indicate negation). Returns true if there is a positive match; zero
390 * otherwise.
391 */
Damien Miller95def091999-11-25 00:26:21 +1100392int match_hostname(const char *host, const char *pattern, unsigned int len);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000393
Damien Miller5428f641999-11-25 11:54:57 +1100394/*
395 * Checks whether the given host is already in the list of our known hosts.
396 * Returns HOST_OK if the host is known and has the specified key, HOST_NEW
397 * if the host is not known, and HOST_CHANGED if the host is known but used
398 * to have a different host key. The host must be in all lowercase.
399 */
Damien Miller95def091999-11-25 00:26:21 +1100400typedef enum {
401 HOST_OK, HOST_NEW, HOST_CHANGED
402} HostStatus;
403HostStatus
404check_host_in_hostfile(const char *filename, const char *host,
405 BIGNUM * e, BIGNUM * n, BIGNUM * ke, BIGNUM * kn);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000406
Damien Miller5428f641999-11-25 11:54:57 +1100407/*
408 * Appends an entry to the host file. Returns false if the entry could not
409 * be appended.
410 */
Damien Miller95def091999-11-25 00:26:21 +1100411int
412add_host_to_hostfile(const char *filename, const char *host,
413 BIGNUM * e, BIGNUM * n);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000414
Damien Miller5428f641999-11-25 11:54:57 +1100415/*
416 * Performs the RSA authentication challenge-response dialog with the client,
417 * and returns true (non-zero) if the client gave the correct answer to our
418 * challenge; returns zero if the client gives a wrong answer.
419 */
Damien Miller95def091999-11-25 00:26:21 +1100420int auth_rsa_challenge_dialog(BIGNUM * e, BIGNUM * n);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000421
Damien Miller5428f641999-11-25 11:54:57 +1100422/*
423 * Reads a passphrase from /dev/tty with echo turned off. Returns the
424 * passphrase (allocated with xmalloc). Exits if EOF is encountered. If
425 * from_stdin is true, the passphrase will be read from stdin instead.
426 */
Damien Miller95def091999-11-25 00:26:21 +1100427char *read_passphrase(const char *prompt, int from_stdin);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000428
Damien Miller5428f641999-11-25 11:54:57 +1100429/*
430 * Saves the authentication (private) key in a file, encrypting it with
431 * passphrase. The identification of the file (lowest 64 bits of n) will
432 * precede the key to provide identification of the key without needing a
433 * passphrase.
434 */
Damien Miller95def091999-11-25 00:26:21 +1100435int
436save_private_key(const char *filename, const char *passphrase,
437 RSA * private_key, const char *comment);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000438
Damien Miller5428f641999-11-25 11:54:57 +1100439/*
440 * Loads the public part of the key file (public key and comment). Returns 0
441 * if an error occurred; zero if the public key was successfully read. The
442 * comment of the key is returned in comment_return if it is non-NULL; the
443 * caller must free the value with xfree.
444 */
Damien Miller95def091999-11-25 00:26:21 +1100445int
446load_public_key(const char *filename, RSA * pub,
447 char **comment_return);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000448
Damien Miller5428f641999-11-25 11:54:57 +1100449/*
450 * Loads the private key from the file. Returns 0 if an error is encountered
451 * (file does not exist or is not readable, or passphrase is bad). This
452 * initializes the private key. The comment of the key is returned in
453 * comment_return if it is non-NULL; the caller must free the value with
454 * xfree.
455 */
Damien Miller95def091999-11-25 00:26:21 +1100456int
457load_private_key(const char *filename, const char *passphrase,
458 RSA * private_key, char **comment_return);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000459
Damien Miller6d7b2cd1999-11-12 15:19:27 +1100460/*------------ Definitions for logging. -----------------------*/
461
462/* Supported syslog facilities and levels. */
Damien Miller95def091999-11-25 00:26:21 +1100463typedef enum {
464 SYSLOG_FACILITY_DAEMON,
465 SYSLOG_FACILITY_USER,
466 SYSLOG_FACILITY_AUTH,
467 SYSLOG_FACILITY_LOCAL0,
468 SYSLOG_FACILITY_LOCAL1,
469 SYSLOG_FACILITY_LOCAL2,
470 SYSLOG_FACILITY_LOCAL3,
471 SYSLOG_FACILITY_LOCAL4,
472 SYSLOG_FACILITY_LOCAL5,
473 SYSLOG_FACILITY_LOCAL6,
474 SYSLOG_FACILITY_LOCAL7
475} SyslogFacility;
Damien Miller6d7b2cd1999-11-12 15:19:27 +1100476
Damien Miller95def091999-11-25 00:26:21 +1100477typedef enum {
478 SYSLOG_LEVEL_QUIET,
479 SYSLOG_LEVEL_FATAL,
480 SYSLOG_LEVEL_ERROR,
481 SYSLOG_LEVEL_INFO,
482 SYSLOG_LEVEL_VERBOSE,
483 SYSLOG_LEVEL_DEBUG
484} LogLevel;
Damien Miller6d7b2cd1999-11-12 15:19:27 +1100485/* Initializes logging. */
Damien Miller95def091999-11-25 00:26:21 +1100486void log_init(char *av0, LogLevel level, SyslogFacility facility, int on_stderr);
Damien Miller6d7b2cd1999-11-12 15:19:27 +1100487
488/* Logging implementation, depending on server or client */
Damien Miller95def091999-11-25 00:26:21 +1100489void do_log(LogLevel level, const char *fmt, va_list args);
Damien Miller6d7b2cd1999-11-12 15:19:27 +1100490
Damien Miller6162d121999-11-21 13:23:52 +1100491/* name to facility/level */
492SyslogFacility log_facility_number(char *name);
493LogLevel log_level_number(char *name);
494
Damien Miller6d7b2cd1999-11-12 15:19:27 +1100495/* Output a message to syslog or stderr */
Damien Miller95def091999-11-25 00:26:21 +1100496void fatal(const char *fmt,...) __attribute__((format(printf, 1, 2)));
497void error(const char *fmt,...) __attribute__((format(printf, 1, 2)));
498void log(const char *fmt,...) __attribute__((format(printf, 1, 2)));
499void verbose(const char *fmt,...) __attribute__((format(printf, 1, 2)));
500void debug(const char *fmt,...) __attribute__((format(printf, 1, 2)));
Damien Miller6d7b2cd1999-11-12 15:19:27 +1100501
502/* same as fatal() but w/o logging */
Damien Miller95def091999-11-25 00:26:21 +1100503void fatal_cleanup(void);
Damien Miller6d7b2cd1999-11-12 15:19:27 +1100504
Damien Miller5428f641999-11-25 11:54:57 +1100505/*
506 * Registers a cleanup function to be called by fatal()/fatal_cleanup()
507 * before exiting. It is permissible to call fatal_remove_cleanup for the
508 * function itself from the function.
509 */
Damien Miller95def091999-11-25 00:26:21 +1100510void fatal_add_cleanup(void (*proc) (void *context), void *context);
Damien Miller6d7b2cd1999-11-12 15:19:27 +1100511
512/* Removes a cleanup function to be called at fatal(). */
Damien Miller95def091999-11-25 00:26:21 +1100513void fatal_remove_cleanup(void (*proc) (void *context), void *context);
Damien Miller6d7b2cd1999-11-12 15:19:27 +1100514
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000515/*---------------- definitions for channels ------------------*/
516
517/* Sets specific protocol options. */
Damien Miller95def091999-11-25 00:26:21 +1100518void channel_set_options(int hostname_in_open);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000519
Damien Miller5428f641999-11-25 11:54:57 +1100520/*
521 * Allocate a new channel object and set its type and socket. Remote_name
522 * must have been allocated with xmalloc; this will free it when the channel
523 * is freed.
524 */
Damien Miller95def091999-11-25 00:26:21 +1100525int channel_allocate(int type, int sock, char *remote_name);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000526
527/* Free the channel and close its socket. */
Damien Miller95def091999-11-25 00:26:21 +1100528void channel_free(int channel);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000529
530/* Add any bits relevant to channels in select bitmasks. */
Damien Miller95def091999-11-25 00:26:21 +1100531void channel_prepare_select(fd_set * readset, fd_set * writeset);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000532
Damien Miller5428f641999-11-25 11:54:57 +1100533/*
534 * After select, perform any appropriate operations for channels which have
535 * events pending.
536 */
Damien Miller95def091999-11-25 00:26:21 +1100537void channel_after_select(fd_set * readset, fd_set * writeset);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000538
539/* If there is data to send to the connection, send some of it now. */
Damien Miller95def091999-11-25 00:26:21 +1100540void channel_output_poll(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000541
Damien Miller5428f641999-11-25 11:54:57 +1100542/*
543 * This is called when a packet of type CHANNEL_DATA has just been received.
544 * The message type has already been consumed, but channel number and data is
545 * still there.
546 */
Damien Miller95def091999-11-25 00:26:21 +1100547void channel_input_data(int payload_len);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000548
549/* Returns true if no channel has too much buffered data. */
Damien Miller95def091999-11-25 00:26:21 +1100550int channel_not_very_much_buffered_data(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000551
552/* This is called after receiving CHANNEL_CLOSE. */
Damien Miller95def091999-11-25 00:26:21 +1100553void channel_input_close(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000554
555/* This is called after receiving CHANNEL_CLOSE_CONFIRMATION. */
Damien Miller95def091999-11-25 00:26:21 +1100556void channel_input_close_confirmation(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000557
558/* This is called after receiving CHANNEL_OPEN_CONFIRMATION. */
Damien Miller95def091999-11-25 00:26:21 +1100559void channel_input_open_confirmation(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000560
561/* This is called after receiving CHANNEL_OPEN_FAILURE from the other side. */
Damien Miller95def091999-11-25 00:26:21 +1100562void channel_input_open_failure(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000563
564/* This closes any sockets that are listening for connections; this removes
565 any unix domain sockets. */
Damien Miller95def091999-11-25 00:26:21 +1100566void channel_stop_listening(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000567
Damien Miller5428f641999-11-25 11:54:57 +1100568/*
569 * Closes the sockets of all channels. This is used to close extra file
570 * descriptors after a fork.
571 */
Damien Miller95def091999-11-25 00:26:21 +1100572void channel_close_all(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000573
574/* Returns the maximum file descriptor number used by the channels. */
Damien Miller95def091999-11-25 00:26:21 +1100575int channel_max_fd(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000576
577/* Returns true if there is still an open channel over the connection. */
Damien Miller95def091999-11-25 00:26:21 +1100578int channel_still_open(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000579
Damien Miller5428f641999-11-25 11:54:57 +1100580/*
581 * Returns a string containing a list of all open channels. The list is
582 * suitable for displaying to the user. It uses crlf instead of newlines.
583 * The caller should free the string with xfree.
584 */
Damien Miller95def091999-11-25 00:26:21 +1100585char *channel_open_message(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000586
Damien Miller5428f641999-11-25 11:54:57 +1100587/*
588 * Initiate forwarding of connections to local port "port" through the secure
589 * channel to host:port from remote side. This never returns if there was an
590 * error.
591 */
Damien Miller95def091999-11-25 00:26:21 +1100592void
Damien Milleraae6c611999-12-06 11:47:28 +1100593channel_request_local_forwarding(u_short port, const char *host,
Damien Millera34a28b1999-12-14 10:47:15 +1100594 u_short remote_port, int gateway_ports);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000595
Damien Miller5428f641999-11-25 11:54:57 +1100596/*
597 * Initiate forwarding of connections to port "port" on remote host through
598 * the secure channel to host:port from local side. This never returns if
599 * there was an error. This registers that open requests for that port are
600 * permitted.
601 */
Damien Miller95def091999-11-25 00:26:21 +1100602void
Damien Milleraae6c611999-12-06 11:47:28 +1100603channel_request_remote_forwarding(u_short port, const char *host,
604 u_short remote_port);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000605
Damien Miller5428f641999-11-25 11:54:57 +1100606/*
607 * Permits opening to any host/port in SSH_MSG_PORT_OPEN. This is usually
608 * called by the server, because the user could connect to any port anyway,
609 * and the server has no way to know but to trust the client anyway.
610 */
Damien Miller95def091999-11-25 00:26:21 +1100611void channel_permit_all_opens(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000612
Damien Miller5428f641999-11-25 11:54:57 +1100613/*
614 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
615 * listening for the port, and sends back a success reply (or disconnect
616 * message if there was an error). This never returns if there was an error.
617 */
Damien Miller95def091999-11-25 00:26:21 +1100618void channel_input_port_forward_request(int is_root);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000619
Damien Miller5428f641999-11-25 11:54:57 +1100620/*
621 * This is called after receiving PORT_OPEN message. This attempts to
622 * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION
623 * or CHANNEL_OPEN_FAILURE.
624 */
Damien Miller95def091999-11-25 00:26:21 +1100625void channel_input_port_open(int payload_len);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000626
Damien Miller5428f641999-11-25 11:54:57 +1100627/*
628 * Creates a port for X11 connections, and starts listening for it. Returns
629 * the display name, or NULL if an error was encountered.
630 */
Damien Miller95def091999-11-25 00:26:21 +1100631char *x11_create_display(int screen);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000632
Damien Miller5428f641999-11-25 11:54:57 +1100633/*
634 * Creates an internet domain socket for listening for X11 connections.
635 * Returns a suitable value for the DISPLAY variable, or NULL if an error
636 * occurs.
637 */
Damien Millera34a28b1999-12-14 10:47:15 +1100638char *x11_create_display_inet(int screen, int x11_display_offset);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000639
Damien Miller5428f641999-11-25 11:54:57 +1100640/*
641 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
642 * the remote channel number. We should do whatever we want, and respond
643 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
644 */
Damien Miller95def091999-11-25 00:26:21 +1100645void x11_input_open(int payload_len);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000646
Damien Miller5428f641999-11-25 11:54:57 +1100647/*
648 * Requests forwarding of X11 connections. This should be called on the
649 * client only.
650 */
Damien Miller95def091999-11-25 00:26:21 +1100651void x11_request_forwarding(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000652
Damien Miller5428f641999-11-25 11:54:57 +1100653/*
654 * Requests forwarding for X11 connections, with authentication spoofing.
655 * This should be called in the client only.
656 */
Damien Miller95def091999-11-25 00:26:21 +1100657void x11_request_forwarding_with_spoofing(const char *proto, const char *data);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000658
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000659/* Sends a message to the server to request authentication fd forwarding. */
Damien Miller95def091999-11-25 00:26:21 +1100660void auth_request_forwarding(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000661
Damien Miller5428f641999-11-25 11:54:57 +1100662/*
663 * Returns the name of the forwarded authentication socket. Returns NULL if
664 * there is no forwarded authentication socket. The returned value points to
665 * a static buffer.
666 */
Damien Miller95def091999-11-25 00:26:21 +1100667char *auth_get_socket_name(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000668
Damien Miller5428f641999-11-25 11:54:57 +1100669/*
670 * This if called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
671 * This starts forwarding authentication requests.
672 */
Damien Miller95def091999-11-25 00:26:21 +1100673void auth_input_request_forwarding(struct passwd * pw);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000674
675/* This is called to process an SSH_SMSG_AGENT_OPEN message. */
Damien Miller95def091999-11-25 00:26:21 +1100676void auth_input_open_request(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000677
Damien Miller5428f641999-11-25 11:54:57 +1100678/*
679 * Returns true if the given string matches the pattern (which may contain ?
680 * and * as wildcards), and zero if it does not match.
681 */
Damien Miller95def091999-11-25 00:26:21 +1100682int match_pattern(const char *s, const char *pattern);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000683
Damien Miller5428f641999-11-25 11:54:57 +1100684/*
685 * Expands tildes in the file name. Returns data allocated by xmalloc.
686 * Warning: this calls getpw*.
687 */
Damien Miller95def091999-11-25 00:26:21 +1100688char *tilde_expand_filename(const char *filename, uid_t my_uid);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000689
Damien Miller5428f641999-11-25 11:54:57 +1100690/*
691 * Performs the interactive session. This handles data transmission between
692 * the client and the program. Note that the notion of stdin, stdout, and
693 * stderr in this function is sort of reversed: this function writes to stdin
694 * (of the child program), and reads from stdout and stderr (of the child
695 * program).
696 */
Damien Miller95def091999-11-25 00:26:21 +1100697void server_loop(int pid, int fdin, int fdout, int fderr);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000698
699/* Client side main loop for the interactive session. */
Damien Miller95def091999-11-25 00:26:21 +1100700int client_loop(int have_pty, int escape_char);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000701
702/* Linked list of custom environment strings (see auth-rsa.c). */
703struct envstring {
Damien Miller95def091999-11-25 00:26:21 +1100704 struct envstring *next;
705 char *s;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000706};
Damien Miller037a0dc1999-12-07 15:38:31 +1100707
708/*
709 * Ensure all of data on socket comes through. f==read || f==write
710 */
711int atomicio(int (*f)(), int fd, void *s, size_t n);
712
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000713#ifdef KRB4
714#include <krb.h>
Damien Miller5428f641999-11-25 11:54:57 +1100715/*
716 * Performs Kerberos v4 mutual authentication with the client. This returns 0
717 * if the client could not be authenticated, and 1 if authentication was
718 * successful. This may exit if there is a serious protocol violation.
719 */
Damien Miller95def091999-11-25 00:26:21 +1100720int auth_krb4(const char *server_user, KTEXT auth, char **client);
721int krb4_init(uid_t uid);
722void krb4_cleanup_proc(void *ignore);
Damien Milleraae6c611999-12-06 11:47:28 +1100723int auth_krb4_password(struct passwd * pw, const char *password);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000724
725#ifdef AFS
726#include <kafs.h>
727
728/* Accept passed Kerberos v4 ticket-granting ticket and AFS tokens. */
Damien Miller95def091999-11-25 00:26:21 +1100729int auth_kerberos_tgt(struct passwd * pw, const char *string);
730int auth_afs_token(struct passwd * pw, const char *token_string);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000731
Damien Miller95def091999-11-25 00:26:21 +1100732int creds_to_radix(CREDENTIALS * creds, unsigned char *buf);
733int radix_to_creds(const char *buf, CREDENTIALS * creds);
734#endif /* AFS */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000735
Damien Miller95def091999-11-25 00:26:21 +1100736#endif /* KRB4 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000737
738#ifdef SKEY
739#include <skey.h>
Damien Miller95def091999-11-25 00:26:21 +1100740char *skey_fake_keyinfo(char *username);
Damien Milleraae6c611999-12-06 11:47:28 +1100741int auth_skey_password(struct passwd * pw, const char *password);
Damien Miller95def091999-11-25 00:26:21 +1100742#endif /* SKEY */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000743
Damien Miller95def091999-11-25 00:26:21 +1100744#endif /* SSH_H */