ssh.h revision 76226
1/* 2 * Author: Tatu Ylonen <ylo@cs.hut.fi> 3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 4 * All rights reserved 5 * 6 * Generic header file for ssh. 7 * 8 * As far as I am concerned, the code I have written for this software 9 * can be used freely for any purpose. Any derived versions of this 10 * software must be clearly marked as such, and if the derived work is 11 * incompatible with the protocol description in the RFC file, it must be 12 * called by a name other than "ssh" or "Secure Shell". 13 */ 14 15/* RCSID("$OpenBSD: ssh.h,v 1.54 2000/10/11 20:27:24 markus Exp $"); */ 16/* $FreeBSD: head/crypto/openssh/ssh.h 76226 2001-05-03 00:26:47Z green $ */ 17 18#ifndef SSH_H 19#define SSH_H 20 21#include "rsa.h" 22#include "cipher.h" 23 24/* Cipher used for encrypting authentication files. */ 25#define SSH_AUTHFILE_CIPHER SSH_CIPHER_3DES 26 27/* Default port number. */ 28#define SSH_DEFAULT_PORT 22 29 30/* Maximum number of TCP/IP ports forwarded per direction. */ 31#define SSH_MAX_FORWARDS_PER_DIRECTION 100 32 33/* 34 * Maximum number of RSA authentication identity files that can be specified 35 * in configuration files or on the command line. 36 */ 37#define SSH_MAX_IDENTITY_FILES 100 38 39/* 40 * Major protocol version. Different version indicates major incompatiblity 41 * that prevents communication. 42 * 43 * Minor protocol version. Different version indicates minor incompatibility 44 * that does not prevent interoperation. 45 */ 46#define PROTOCOL_MAJOR_1 1 47#define PROTOCOL_MINOR_1 5 48 49/* We support both SSH1 and SSH2 */ 50#define PROTOCOL_MAJOR_2 2 51#define PROTOCOL_MINOR_2 0 52 53/* 54 * Name for the service. The port named by this service overrides the 55 * default port if present. 56 */ 57#define SSH_SERVICE_NAME "ssh" 58 59#define ETCDIR "/etc/ssh" 60#define PIDDIR "/var/run" 61 62/* 63 * System-wide file containing host keys of known hosts. This file should be 64 * world-readable. 65 */ 66#define SSH_SYSTEM_HOSTFILE ETCDIR "/ssh_known_hosts" 67#define SSH_SYSTEM_HOSTFILE2 ETCDIR "/ssh_known_hosts2" 68 69/* 70 * Of these, ssh_host_key must be readable only by root, whereas ssh_config 71 * should be world-readable. 72 */ 73#define HOST_KEY_FILE ETCDIR "/ssh_host_key" 74#define SERVER_CONFIG_FILE ETCDIR "/sshd_config" 75#define HOST_CONFIG_FILE ETCDIR "/ssh_config" 76#define HOST_DSA_KEY_FILE ETCDIR "/ssh_host_dsa_key" 77#define DH_PRIMES ETCDIR "/primes" 78 79#define SSH_PROGRAM "/usr/bin/ssh" 80 81/* 82 * The process id of the daemon listening for connections is saved here to 83 * make it easier to kill the correct daemon when necessary. 84 */ 85#define SSH_DAEMON_PID_FILE PIDDIR "/sshd.pid" 86 87/* 88 * The directory in user\'s home directory in which the files reside. The 89 * directory should be world-readable (though not all files are). 90 */ 91#define SSH_USER_DIR ".ssh" 92 93/* 94 * Per-user file containing host keys of known hosts. This file need not be 95 * readable by anyone except the user him/herself, though this does not 96 * contain anything particularly secret. 97 */ 98#define SSH_USER_HOSTFILE "~/.ssh/known_hosts" 99#define SSH_USER_HOSTFILE2 "~/.ssh/known_hosts2" 100 101/* 102 * Name of the default file containing client-side authentication key. This 103 * file should only be readable by the user him/herself. 104 */ 105#define SSH_CLIENT_IDENTITY ".ssh/identity" 106#define SSH_CLIENT_ID_DSA ".ssh/id_dsa" 107 108/* 109 * Configuration file in user\'s home directory. This file need not be 110 * readable by anyone but the user him/herself, but does not contain anything 111 * particularly secret. If the user\'s home directory resides on an NFS 112 * volume where root is mapped to nobody, this may need to be world-readable. 113 */ 114#define SSH_USER_CONFFILE ".ssh/config" 115 116/* 117 * File containing a list of those rsa keys that permit logging in as this 118 * user. This file need not be readable by anyone but the user him/herself, 119 * but does not contain anything particularly secret. If the user\'s home 120 * directory resides on an NFS volume where root is mapped to nobody, this 121 * may need to be world-readable. (This file is read by the daemon which is 122 * running as root.) 123 */ 124#define SSH_USER_PERMITTED_KEYS ".ssh/authorized_keys" 125#define SSH_USER_PERMITTED_KEYS2 ".ssh/authorized_keys2" 126 127/* 128 * Per-user and system-wide ssh "rc" files. These files are executed with 129 * /bin/sh before starting the shell or command if they exist. They will be 130 * passed "proto cookie" as arguments if X11 forwarding with spoofing is in 131 * use. xauth will be run if neither of these exists. 132 */ 133#define SSH_USER_RC ".ssh/rc" 134#define SSH_SYSTEM_RC ETCDIR "/sshrc" 135 136/* 137 * Ssh-only version of /etc/hosts.equiv. Additionally, the daemon may use 138 * ~/.rhosts and /etc/hosts.equiv if rhosts authentication is enabled. 139 */ 140#define SSH_HOSTS_EQUIV ETCDIR "/shosts.equiv" 141 142/* 143 * Name of the environment variable containing the pathname of the 144 * authentication socket. 145 */ 146#define SSH_AUTHSOCKET_ENV_NAME "SSH_AUTH_SOCK" 147 148/* 149 * Name of the environment variable containing the pathname of the 150 * authentication socket. 151 */ 152#define SSH_AGENTPID_ENV_NAME "SSH_AGENT_PID" 153 154/* 155 * Default path to ssh-askpass used by ssh-add, 156 * environment variable for overwriting the default location 157 */ 158#define SSH_ASKPASS_DEFAULT "/usr/X11R6/bin/ssh-askpass" 159#define SSH_ASKPASS_ENV "SSH_ASKPASS" 160 161/* 162 * Force host key length and server key length to differ by at least this 163 * many bits. This is to make double encryption with rsaref work. 164 */ 165#define SSH_KEY_BITS_RESERVED 128 166 167/* 168 * Length of the session key in bytes. (Specified as 256 bits in the 169 * protocol.) 170 */ 171#define SSH_SESSION_KEY_LENGTH 32 172 173/* Name of Kerberos service for SSH to use. */ 174#define KRB4_SERVICE_NAME "rcmd" 175 176/* 177 * Authentication methods. New types can be added, but old types should not 178 * be removed for compatibility. The maximum allowed value is 31. 179 */ 180#define SSH_AUTH_RHOSTS 1 181#define SSH_AUTH_RSA 2 182#define SSH_AUTH_PASSWORD 3 183#define SSH_AUTH_RHOSTS_RSA 4 184#define SSH_AUTH_TIS 5 185#define SSH_AUTH_KERBEROS 6 186#define SSH_PASS_KERBEROS_TGT 7 187 /* 8 to 15 are reserved */ 188#define SSH_PASS_AFS_TOKEN 21 189 190/* Protocol flags. These are bit masks. */ 191#define SSH_PROTOFLAG_SCREEN_NUMBER 1 /* X11 forwarding includes screen */ 192#define SSH_PROTOFLAG_HOST_IN_FWD_OPEN 2 /* forwarding opens contain host */ 193 194/* 195 * Definition of message types. New values can be added, but old values 196 * should not be removed or without careful consideration of the consequences 197 * for compatibility. The maximum value is 254; value 255 is reserved for 198 * future extension. 199 */ 200/* Message name */ /* msg code */ /* arguments */ 201#define SSH_MSG_NONE 0 /* no message */ 202#define SSH_MSG_DISCONNECT 1 /* cause (string) */ 203#define SSH_SMSG_PUBLIC_KEY 2 /* ck,msk,srvk,hostk */ 204#define SSH_CMSG_SESSION_KEY 3 /* key (BIGNUM) */ 205#define SSH_CMSG_USER 4 /* user (string) */ 206#define SSH_CMSG_AUTH_RHOSTS 5 /* user (string) */ 207#define SSH_CMSG_AUTH_RSA 6 /* modulus (BIGNUM) */ 208#define SSH_SMSG_AUTH_RSA_CHALLENGE 7 /* int (BIGNUM) */ 209#define SSH_CMSG_AUTH_RSA_RESPONSE 8 /* int (BIGNUM) */ 210#define SSH_CMSG_AUTH_PASSWORD 9 /* pass (string) */ 211#define SSH_CMSG_REQUEST_PTY 10 /* TERM, tty modes */ 212#define SSH_CMSG_WINDOW_SIZE 11 /* row,col,xpix,ypix */ 213#define SSH_CMSG_EXEC_SHELL 12 /* */ 214#define SSH_CMSG_EXEC_CMD 13 /* cmd (string) */ 215#define SSH_SMSG_SUCCESS 14 /* */ 216#define SSH_SMSG_FAILURE 15 /* */ 217#define SSH_CMSG_STDIN_DATA 16 /* data (string) */ 218#define SSH_SMSG_STDOUT_DATA 17 /* data (string) */ 219#define SSH_SMSG_STDERR_DATA 18 /* data (string) */ 220#define SSH_CMSG_EOF 19 /* */ 221#define SSH_SMSG_EXITSTATUS 20 /* status (int) */ 222#define SSH_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* channel (int) */ 223#define SSH_MSG_CHANNEL_OPEN_FAILURE 22 /* channel (int) */ 224#define SSH_MSG_CHANNEL_DATA 23 /* ch,data (int,str) */ 225#define SSH_MSG_CHANNEL_CLOSE 24 /* channel (int) */ 226#define SSH_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* channel (int) */ 227/* SSH_CMSG_X11_REQUEST_FORWARDING 26 OBSOLETE */ 228#define SSH_SMSG_X11_OPEN 27 /* channel (int) */ 229#define SSH_CMSG_PORT_FORWARD_REQUEST 28 /* p,host,hp (i,s,i) */ 230#define SSH_MSG_PORT_OPEN 29 /* ch,h,p (i,s,i) */ 231#define SSH_CMSG_AGENT_REQUEST_FORWARDING 30 /* */ 232#define SSH_SMSG_AGENT_OPEN 31 /* port (int) */ 233#define SSH_MSG_IGNORE 32 /* string */ 234#define SSH_CMSG_EXIT_CONFIRMATION 33 /* */ 235#define SSH_CMSG_X11_REQUEST_FORWARDING 34 /* proto,data (s,s) */ 236#define SSH_CMSG_AUTH_RHOSTS_RSA 35 /* user,mod (s,mpi) */ 237#define SSH_MSG_DEBUG 36 /* string */ 238#define SSH_CMSG_REQUEST_COMPRESSION 37 /* level 1-9 (int) */ 239#define SSH_CMSG_MAX_PACKET_SIZE 38 /* size 4k-1024k (int) */ 240#define SSH_CMSG_AUTH_TIS 39 /* we use this for s/key */ 241#define SSH_SMSG_AUTH_TIS_CHALLENGE 40 /* challenge (string) */ 242#define SSH_CMSG_AUTH_TIS_RESPONSE 41 /* response (string) */ 243#define SSH_CMSG_AUTH_KERBEROS 42 /* (KTEXT) */ 244#define SSH_SMSG_AUTH_KERBEROS_RESPONSE 43 /* (KTEXT) */ 245#define SSH_CMSG_HAVE_KERBEROS_TGT 44 246#define SSH_CMSG_HAVE_AFS_TOKEN 65 /* token (s) */ 247 248/* Kerberos IV tickets can't be forwarded. This is an AFS hack! */ 249#define SSH_CMSG_HAVE_KRB4_TGT SSH_CMSG_HAVE_KERBEROS_TGT /* credentials (s) */ 250 251/*------------ definitions for login.c -------------*/ 252 253/* 254 * Returns the time when the user last logged in. Returns 0 if the 255 * information is not available. This must be called before record_login. 256 * The host from which the user logged in is stored in buf. 257 */ 258unsigned long 259get_last_login_time(uid_t uid, const char *logname, 260 char *buf, unsigned int bufsize); 261 262/* 263 * Records that the user has logged in. This does many things normally done 264 * by login(1). 265 */ 266void 267record_login(pid_t pid, const char *ttyname, const char *user, uid_t uid, 268 const char *host, struct sockaddr *addr); 269 270/* 271 * Records that the user has logged out. This does many thigs normally done 272 * by login(1) or init. 273 */ 274void record_logout(pid_t pid, const char *ttyname); 275 276/*------------ definitions for sshconnect.c ----------*/ 277 278/* 279 * Opens a TCP/IP connection to the remote server on the given host. If port 280 * is 0, the default port will be used. If anonymous is zero, a privileged 281 * port will be allocated to make the connection. This requires super-user 282 * privileges if anonymous is false. Connection_attempts specifies the 283 * maximum number of tries, one per second. This returns true on success, 284 * and zero on failure. If the connection is successful, this calls 285 * packet_set_connection for the connection. 286 */ 287int 288ssh_connect(const char *host, struct sockaddr_storage * hostaddr, 289 u_short port, int connection_attempts, 290 int anonymous, uid_t original_real_uid, 291 const char *proxy_command); 292 293/* 294 * Starts a dialog with the server, and authenticates the current user on the 295 * server. This does not need any extra privileges. The basic connection to 296 * the server must already have been established before this is called. If 297 * login fails, this function prints an error and never returns. This 298 * initializes the random state, and leaves it initialized (it will also have 299 * references from the packet module). 300 */ 301 302void 303ssh_login(int host_key_valid, RSA * host_key, const char *host, 304 struct sockaddr * hostaddr, uid_t original_real_uid); 305 306/*------------ Definitions for various authentication methods. -------*/ 307 308/* 309 * Tries to authenticate the user using the .rhosts file. Returns true if 310 * authentication succeeds. If ignore_rhosts is non-zero, this will not 311 * consider .rhosts and .shosts (/etc/hosts.equiv will still be used). 312 */ 313int auth_rhosts(struct passwd * pw, const char *client_user); 314 315/* 316 * Tries to authenticate the user using the .rhosts file and the host using 317 * its host key. Returns true if authentication succeeds. 318 */ 319int 320auth_rhosts_rsa(struct passwd * pw, const char *client_user, RSA* client_host_key); 321 322/* 323 * Tries to authenticate the user using password. Returns true if 324 * authentication succeeds. 325 */ 326int auth_password(struct passwd * pw, const char *password); 327 328/* 329 * Performs the RSA authentication dialog with the client. This returns 0 if 330 * the client could not be authenticated, and 1 if authentication was 331 * successful. This may exit if there is a serious protocol violation. 332 */ 333int auth_rsa(struct passwd * pw, BIGNUM * client_n); 334 335/* 336 * Parses an RSA key (number of bits, e, n) from a string. Moves the pointer 337 * over the key. Skips any whitespace at the beginning and at end. 338 */ 339int auth_rsa_read_key(char **cpp, unsigned int *bitsp, BIGNUM * e, BIGNUM * n); 340 341/* 342 * Returns the name of the machine at the other end of the socket. The 343 * returned string should be freed by the caller. 344 */ 345char *get_remote_hostname(int socket); 346 347/* 348 * Return the canonical name of the host in the other side of the current 349 * connection (as returned by packet_get_connection). The host name is 350 * cached, so it is efficient to call this several times. 351 */ 352const char *get_canonical_hostname(void); 353 354/* 355 * Returns the local IP address as an ascii string. 356 */ 357const char *get_ipaddr(int socket); 358 359/* 360 * Returns the remote IP address as an ascii string. The value need not be 361 * freed by the caller. 362 */ 363const char *get_remote_ipaddr(void); 364 365/* Returns the port number of the peer of the socket. */ 366int get_peer_port(int sock); 367 368/* Returns the port number of the remote/local host. */ 369int get_remote_port(void); 370int get_local_port(void); 371 372 373/* 374 * Performs the RSA authentication challenge-response dialog with the client, 375 * and returns true (non-zero) if the client gave the correct answer to our 376 * challenge; returns zero if the client gives a wrong answer. 377 */ 378int auth_rsa_challenge_dialog(RSA *pk); 379 380/* 381 * Reads a passphrase from /dev/tty with echo turned off. Returns the 382 * passphrase (allocated with xmalloc). Exits if EOF is encountered. If 383 * from_stdin is true, the passphrase will be read from stdin instead. 384 */ 385char *read_passphrase(char *prompt, int from_stdin); 386 387 388/*------------ Definitions for logging. -----------------------*/ 389 390/* Supported syslog facilities and levels. */ 391typedef enum { 392 SYSLOG_FACILITY_DAEMON, 393 SYSLOG_FACILITY_USER, 394 SYSLOG_FACILITY_AUTH, 395 SYSLOG_FACILITY_LOCAL0, 396 SYSLOG_FACILITY_LOCAL1, 397 SYSLOG_FACILITY_LOCAL2, 398 SYSLOG_FACILITY_LOCAL3, 399 SYSLOG_FACILITY_LOCAL4, 400 SYSLOG_FACILITY_LOCAL5, 401 SYSLOG_FACILITY_LOCAL6, 402 SYSLOG_FACILITY_LOCAL7 403} SyslogFacility; 404 405typedef enum { 406 SYSLOG_LEVEL_QUIET, 407 SYSLOG_LEVEL_FATAL, 408 SYSLOG_LEVEL_ERROR, 409 SYSLOG_LEVEL_INFO, 410 SYSLOG_LEVEL_VERBOSE, 411 SYSLOG_LEVEL_DEBUG1, 412 SYSLOG_LEVEL_DEBUG2, 413 SYSLOG_LEVEL_DEBUG3 414} LogLevel; 415/* Initializes logging. */ 416void log_init(char *av0, LogLevel level, SyslogFacility facility, int on_stderr); 417 418/* Logging implementation, depending on server or client */ 419void do_log(LogLevel level, const char *fmt, va_list args); 420 421/* name to facility/level */ 422SyslogFacility log_facility_number(char *name); 423LogLevel log_level_number(char *name); 424 425/* Output a message to syslog or stderr */ 426void fatal(const char *fmt,...) __attribute__((format(printf, 1, 2))); 427void error(const char *fmt,...) __attribute__((format(printf, 1, 2))); 428void log(const char *fmt,...) __attribute__((format(printf, 1, 2))); 429void verbose(const char *fmt,...) __attribute__((format(printf, 1, 2))); 430void debug(const char *fmt,...) __attribute__((format(printf, 1, 2))); 431void debug2(const char *fmt,...) __attribute__((format(printf, 1, 2))); 432void debug3(const char *fmt,...) __attribute__((format(printf, 1, 2))); 433 434/* same as fatal() but w/o logging */ 435void fatal_cleanup(void); 436 437/* 438 * Registers a cleanup function to be called by fatal()/fatal_cleanup() 439 * before exiting. It is permissible to call fatal_remove_cleanup for the 440 * function itself from the function. 441 */ 442void fatal_add_cleanup(void (*proc) (void *context), void *context); 443 444/* Removes a cleanup function to be called at fatal(). */ 445void fatal_remove_cleanup(void (*proc) (void *context), void *context); 446 447/* ---- misc */ 448 449/* 450 * Expands tildes in the file name. Returns data allocated by xmalloc. 451 * Warning: this calls getpw*. 452 */ 453char *tilde_expand_filename(const char *filename, uid_t my_uid); 454 455/* remove newline at end of string */ 456char *chop(char *s); 457 458/* return next token in configuration line */ 459char *strdelim(char **s); 460 461/* set filedescriptor to non-blocking */ 462void set_nonblock(int fd); 463 464/* 465 * Performs the interactive session. This handles data transmission between 466 * the client and the program. Note that the notion of stdin, stdout, and 467 * stderr in this function is sort of reversed: this function writes to stdin 468 * (of the child program), and reads from stdout and stderr (of the child 469 * program). 470 */ 471void server_loop(pid_t pid, int fdin, int fdout, int fderr); 472void server_loop2(void); 473 474/* Client side main loop for the interactive session. */ 475int client_loop(int have_pty, int escape_char, int id); 476 477/* Linked list of custom environment strings (see auth-rsa.c). */ 478struct envstring { 479 struct envstring *next; 480 char *s; 481}; 482 483/* 484 * Ensure all of data on socket comes through. f==read || f==write 485 */ 486ssize_t atomicio(ssize_t (*f)(), int fd, void *s, size_t n); 487 488#ifdef KRB5 489#include <krb5.h> 490int auth_krb5(); /* XXX Doplnit prototypy */ 491int auth_krb5_tgt(); 492int krb5_init(); 493void krb5_cleanup_proc(void *ignore); 494int auth_krb5_password(struct passwd *pw, const char *password); 495#endif /* KRB5 */ 496 497#ifdef KRB4 498#include <krb.h> 499/* 500 * Performs Kerberos v4 mutual authentication with the client. This returns 0 501 * if the client could not be authenticated, and 1 if authentication was 502 * successful. This may exit if there is a serious protocol violation. 503 */ 504int auth_krb4(const char *server_user, KTEXT auth, char **client); 505int krb4_init(uid_t uid); 506void krb4_cleanup_proc(void *ignore); 507int auth_krb4_password(struct passwd * pw, const char *password); 508 509#ifdef AFS 510#include <kafs.h> 511 512/* Accept passed Kerberos v4 ticket-granting ticket and AFS tokens. */ 513int auth_krb4_tgt(struct passwd * pw, const char *string); 514int auth_afs_token(struct passwd * pw, const char *token_string); 515 516int creds_to_radix(CREDENTIALS * creds, unsigned char *buf, size_t buflen); 517int radix_to_creds(const char *buf, CREDENTIALS * creds); 518#endif /* AFS */ 519 520#endif /* KRB4 */ 521 522#ifdef SKEY 523#include <opie.h> 524char *skey_fake_keyinfo(char *username); 525int auth_skey_password(struct passwd * pw, const char *password); 526#endif /* SKEY */ 527 528/* AF_UNSPEC or AF_INET or AF_INET6 */ 529extern int IPv4or6; 530 531#ifdef USE_PAM 532#include "auth-pam.h" 533#endif /* USE_PAM */ 534 535#endif /* SSH_H */ 536