/* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland * All rights reserved * * Generic header file for ssh. * * As far as I am concerned, the code I have written for this software * can be used freely for any purpose. Any derived versions of this * software must be clearly marked as such, and if the derived work is * incompatible with the protocol description in the RFC file, it must be * called by a name other than "ssh" or "Secure Shell". */ /* RCSID("$OpenBSD: ssh.h,v 1.60 2001/01/19 15:55:11 markus Exp $"); */ #ifndef SSH_H #define SSH_H #include "rsa.h" #include "cipher.h" /* Cipher used for encrypting authentication files. */ #define SSH_AUTHFILE_CIPHER SSH_CIPHER_3DES /* Default port number. */ #define SSH_DEFAULT_PORT 22 /* Maximum number of TCP/IP ports forwarded per direction. */ #define SSH_MAX_FORWARDS_PER_DIRECTION 100 /* * Maximum number of RSA authentication identity files that can be specified * in configuration files or on the command line. */ #define SSH_MAX_IDENTITY_FILES 100 /* * Major protocol version. Different version indicates major incompatiblity * that prevents communication. * * Minor protocol version. Different version indicates minor incompatibility * that does not prevent interoperation. */ #define PROTOCOL_MAJOR_1 1 #define PROTOCOL_MINOR_1 5 /* We support both SSH1 and SSH2 */ #define PROTOCOL_MAJOR_2 2 #define PROTOCOL_MINOR_2 0 /* * Name for the service. The port named by this service overrides the * default port if present. */ #define SSH_SERVICE_NAME "ssh" /* * Name of the environment variable containing the pathname of the * authentication socket. */ #define SSH_AGENTPID_ENV_NAME "SSH_AGENT_PID" /* * Name of the environment variable containing the pathname of the * authentication socket. */ #define SSH_AUTHSOCKET_ENV_NAME "SSH_AUTH_SOCK" /* * Environment variable for overwriting the default location of askpass */ #define SSH_ASKPASS_ENV "SSH_ASKPASS" /* * Force host key length and server key length to differ by at least this * many bits. This is to make double encryption with rsaref work. */ #define SSH_KEY_BITS_RESERVED 128 /* * Length of the session key in bytes. (Specified as 256 bits in the * protocol.) */ #define SSH_SESSION_KEY_LENGTH 32 /* Name of Kerberos service for SSH to use. */ #define KRB4_SERVICE_NAME "rcmd" /*------------ definitions for login.c -------------*/ /* * Returns the time when the user last logged in. Returns 0 if the * information is not available. This must be called before record_login. * The host from which the user logged in is stored in buf. */ u_long get_last_login_time(uid_t uid, const char *logname, char *buf, u_int bufsize); /* * Records that the user has logged in. This does many things normally done * by login(1). */ void record_login(pid_t pid, const char *ttyname, const char *user, uid_t uid, const char *host, struct sockaddr *addr); /* * Records that the user has logged out. This does many thigs normally done * by login(1) or init. */ void record_logout(pid_t pid, const char *ttyname); /*------------ definitions for sshconnect.c ----------*/ /* * Opens a TCP/IP connection to the remote server on the given host. If port * is 0, the default port will be used. If anonymous is zero, a privileged * port will be allocated to make the connection. This requires super-user * privileges if anonymous is false. Connection_attempts specifies the * maximum number of tries, one per second. This returns true on success, * and zero on failure. If the connection is successful, this calls * packet_set_connection for the connection. */ int ssh_connect(const char *host, struct sockaddr_storage * hostaddr, u_short port, int connection_attempts, int anonymous, uid_t original_real_uid, const char *proxy_command); /* * Starts a dialog with the server, and authenticates the current user on the * server. This does not need any extra privileges. The basic connection to * the server must already have been established before this is called. If * login fails, this function prints an error and never returns. This * initializes the random state, and leaves it initialized (it will also have * references from the packet module). */ void ssh_login(int host_key_valid, RSA * host_key, const char *host, struct sockaddr * hostaddr, uid_t original_real_uid); /*------------ Definitions for various authentication methods. -------*/ /* * Tries to authenticate the user using the .rhosts file. Returns true if * authentication succeeds. If ignore_rhosts is non-zero, this will not * consider .rhosts and .shosts (/etc/hosts.equiv will still be used). */ int auth_rhosts(struct passwd * pw, const char *client_user); /* * Tries to authenticate the user using the .rhosts file and the host using * its host key. Returns true if authentication succeeds. */ int auth_rhosts_rsa(struct passwd * pw, const char *client_user, RSA* client_host_key); /* * Tries to authenticate the user using password. Returns true if * authentication succeeds. */ int auth_password(struct passwd * pw, const char *password); /* * Performs the RSA authentication dialog with the client. This returns 0 if * the client could not be authenticated, and 1 if authentication was * successful. This may exit if there is a serious protocol violation. */ int auth_rsa(struct passwd * pw, BIGNUM * client_n); /* * Parses an RSA key (number of bits, e, n) from a string. Moves the pointer * over the key. Skips any whitespace at the beginning and at end. */ int auth_rsa_read_key(char **cpp, u_int *bitsp, BIGNUM * e, BIGNUM * n); /* * Returns the name of the machine at the other end of the socket. The * returned string should be freed by the caller. */ char *get_remote_hostname(int socket); /* * Return the canonical name of the host in the other side of the current * connection (as returned by packet_get_connection). The host name is * cached, so it is efficient to call this several times. */ const char *get_canonical_hostname(void); /* * Returns the remote IP address as an ascii string. The value need not be * freed by the caller. */ const char *get_remote_ipaddr(void); /* Returns the port number of the peer of the socket. */ int get_peer_port(int sock); /* Returns the port number of the remote/local host. */ int get_remote_port(void); int get_local_port(void); /* * Performs the RSA authentication challenge-response dialog with the client, * and returns true (non-zero) if the client gave the correct answer to our * challenge; returns zero if the client gives a wrong answer. */ int auth_rsa_challenge_dialog(RSA *pk); /* * Reads a passphrase from /dev/tty with echo turned off. Returns the * passphrase (allocated with xmalloc). Exits if EOF is encountered. If * from_stdin is true, the passphrase will be read from stdin instead. */ char *read_passphrase(char *prompt, int from_stdin); /*------------ Definitions for logging. -----------------------*/ /* Supported syslog facilities and levels. */ typedef enum { SYSLOG_FACILITY_DAEMON, SYSLOG_FACILITY_USER, SYSLOG_FACILITY_AUTH, SYSLOG_FACILITY_LOCAL0, SYSLOG_FACILITY_LOCAL1, SYSLOG_FACILITY_LOCAL2, SYSLOG_FACILITY_LOCAL3, SYSLOG_FACILITY_LOCAL4, SYSLOG_FACILITY_LOCAL5, SYSLOG_FACILITY_LOCAL6, SYSLOG_FACILITY_LOCAL7 } SyslogFacility; typedef enum { SYSLOG_LEVEL_QUIET, SYSLOG_LEVEL_FATAL, SYSLOG_LEVEL_ERROR, SYSLOG_LEVEL_INFO, SYSLOG_LEVEL_VERBOSE, SYSLOG_LEVEL_DEBUG1, SYSLOG_LEVEL_DEBUG2, SYSLOG_LEVEL_DEBUG3 } LogLevel; /* Initializes logging. */ void log_init(char *av0, LogLevel level, SyslogFacility facility, int on_stderr); /* Logging implementation, depending on server or client */ void do_log(LogLevel level, const char *fmt, va_list args); /* name to facility/level */ SyslogFacility log_facility_number(char *name); LogLevel log_level_number(char *name); /* Output a message to syslog or stderr */ void fatal(const char *fmt,...) __attribute__((format(printf, 1, 2))); void error(const char *fmt,...) __attribute__((format(printf, 1, 2))); void log(const char *fmt,...) __attribute__((format(printf, 1, 2))); void verbose(const char *fmt,...) __attribute__((format(printf, 1, 2))); void debug(const char *fmt,...) __attribute__((format(printf, 1, 2))); void debug2(const char *fmt,...) __attribute__((format(printf, 1, 2))); void debug3(const char *fmt,...) __attribute__((format(printf, 1, 2))); /* same as fatal() but w/o logging */ void fatal_cleanup(void); /* * Registers a cleanup function to be called by fatal()/fatal_cleanup() * before exiting. It is permissible to call fatal_remove_cleanup for the * function itself from the function. */ void fatal_add_cleanup(void (*proc) (void *context), void *context); /* Removes a cleanup function to be called at fatal(). */ void fatal_remove_cleanup(void (*proc) (void *context), void *context); /* ---- misc */ /* * Expands tildes in the file name. Returns data allocated by xmalloc. * Warning: this calls getpw*. */ char *tilde_expand_filename(const char *filename, uid_t my_uid); /* remove newline at end of string */ char *chop(char *s); /* return next token in configuration line */ char *strdelim(char **s); /* set filedescriptor to non-blocking */ void set_nonblock(int fd); /* * Performs the interactive session. This handles data transmission between * the client and the program. Note that the notion of stdin, stdout, and * stderr in this function is sort of reversed: this function writes to stdin * (of the child program), and reads from stdout and stderr (of the child * program). */ void server_loop(pid_t pid, int fdin, int fdout, int fderr); void server_loop2(void); /* Client side main loop for the interactive session. */ int client_loop(int have_pty, int escape_char, int id); /* Linked list of custom environment strings (see auth-rsa.c). */ struct envstring { struct envstring *next; char *s; }; /* * Ensure all of data on socket comes through. f==read || f==write */ ssize_t atomicio(ssize_t (*f)(), int fd, void *s, size_t n); #ifdef KRB4 #include /* * Performs Kerberos v4 mutual authentication with the client. This returns 0 * if the client could not be authenticated, and 1 if authentication was * successful. This may exit if there is a serious protocol violation. */ int auth_krb4(const char *server_user, KTEXT auth, char **client); int krb4_init(uid_t uid); void krb4_cleanup_proc(void *ignore); int auth_krb4_password(struct passwd * pw, const char *password); #ifdef AFS #include /* Accept passed Kerberos v4 ticket-granting ticket and AFS tokens. */ int auth_kerberos_tgt(struct passwd * pw, const char *string); int auth_afs_token(struct passwd * pw, const char *token_string); int creds_to_radix(CREDENTIALS * creds, u_char *buf, size_t buflen); int radix_to_creds(const char *buf, CREDENTIALS * creds); #endif /* AFS */ #endif /* KRB4 */ /* AF_UNSPEC or AF_INET or AF_INET6 */ extern int IPv4or6; #endif /* SSH_H */