X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/74fc9186bd338b4b69bb19eea19c1f6dabb4b813..HEAD:/ssh.h diff --git a/ssh.h b/ssh.h index 213f73de..186cfff9 100644 --- a/ssh.h +++ b/ssh.h @@ -1,41 +1,16 @@ +/* $OpenBSD: ssh.h,v 1.78 2006/08/03 03:34:42 deraadt Exp $ */ + /* - * - * ssh.h - * * Author: Tatu Ylonen - * * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland * All rights reserved * - * Created: Fri Mar 17 17:09:37 1995 ylo - * - * Generic header file for ssh. - * - */ - -/* RCSID("$OpenBSD: ssh.h,v 1.47 2000/06/20 01:39:45 markus Exp $"); */ - -#ifndef SSH_H -#define SSH_H - -#include /* For struct sockaddr_in */ -#include /* For struct pw */ -#include /* For va_list */ -#include /* For struct sockaddr_storage */ -#include "fake-socket.h" /* For struct sockaddr_storage */ -#ifdef HAVE_SYS_SELECT_H -# include -#endif -#include "rsa.h" -#include "cipher.h" - -/* - * XXX - * The default cipher used if IDEA is not supported by the remote host. It is - * recommended that this be one of the mandatory ciphers (DES, 3DES), though - * that is not required. + * 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". */ -#define SSH_FALLBACK_CIPHER SSH_CIPHER_3DES /* Cipher used for encrypting authentication files. */ #define SSH_AUTHFILE_CIPHER SSH_CIPHER_3DES @@ -53,7 +28,14 @@ #define SSH_MAX_IDENTITY_FILES 100 /* - * Major protocol version. Different version indicates major incompatiblity + * Maximum length of lines in authorized_keys file. + * Current value permits 16kbit RSA and RSA1 keys and 8kbit DSA keys, with + * some room for options and comments. + */ +#define SSH_MAX_PUBKEY_BYTES 8192 + +/* + * Major protocol version. Different version indicates major incompatibility * that prevents communication. * * Minor protocol version. Different version indicates minor incompatibility @@ -72,136 +54,21 @@ */ #define SSH_SERVICE_NAME "ssh" -#if defined(USE_PAM) && !defined(SSHD_PAM_SERVICE) -# define SSHD_PAM_SERVICE "sshd" -#endif - -#ifndef ETCDIR -#define ETCDIR "/etc" -#endif /* ETCDIR */ - -#ifndef PIDDIR -#define PIDDIR "/var/run" -#endif /* PIDDIR */ - /* - * System-wide file containing host keys of known hosts. This file should be - * world-readable. + * Name of the environment variable containing the process ID of the + * authentication agent. */ -#define SSH_SYSTEM_HOSTFILE ETCDIR "/ssh_known_hosts" -#define SSH_SYSTEM_HOSTFILE2 ETCDIR "/ssh_known_hosts2" - -/* - * Of these, ssh_host_key must be readable only by root, whereas ssh_config - * should be world-readable. - */ -#define HOST_KEY_FILE ETCDIR "/ssh_host_key" -#define SERVER_CONFIG_FILE ETCDIR "/sshd_config" -#define HOST_CONFIG_FILE ETCDIR "/ssh_config" -#define HOST_DSA_KEY_FILE ETCDIR "/ssh_host_dsa_key" - -#ifndef SSH_PROGRAM -#define SSH_PROGRAM "/usr/bin/ssh" -#endif /* SSH_PROGRAM */ - -#ifndef LOGIN_PROGRAM -#define LOGIN_PROGRAM "/usr/bin/login" -#endif /* LOGIN_PROGRAM */ - -#ifndef ASKPASS_PROGRAM -#define ASKPASS_PROGRAM "/usr/lib/ssh/ssh-askpass" -#endif /* ASKPASS_PROGRAM */ - -/* - * The process id of the daemon listening for connections is saved here to - * make it easier to kill the correct daemon when necessary. - */ -#define SSH_DAEMON_PID_FILE PIDDIR "/sshd.pid" - -/* - * The directory in user\'s home directory in which the files reside. The - * directory should be world-readable (though not all files are). - */ -#define SSH_USER_DIR ".ssh" - -/* - * Relevant only when using builtin PRNG. - */ -#ifndef SSH_PRNG_SEED_FILE -# define SSH_PRNG_SEED_FILE SSH_USER_DIR"/prng_seed" -#endif /* SSH_PRNG_SEED_FILE */ -#ifndef SSH_PRNG_COMMAND_FILE -# define SSH_PRNG_COMMAND_FILE ETCDIR "/ssh_prng_cmds" -#endif /* SSH_PRNG_COMMAND_FILE */ - -/* - * Per-user file containing host keys of known hosts. This file need not be - * readable by anyone except the user him/herself, though this does not - * contain anything particularly secret. - */ -#define SSH_USER_HOSTFILE "~/.ssh/known_hosts" -#define SSH_USER_HOSTFILE2 "~/.ssh/known_hosts2" - -/* - * Name of the default file containing client-side authentication key. This - * file should only be readable by the user him/herself. - */ -#define SSH_CLIENT_IDENTITY ".ssh/identity" -#define SSH_CLIENT_ID_DSA ".ssh/id_dsa" - -/* - * Configuration file in user\'s home directory. This file need not be - * readable by anyone but the user him/herself, but does not contain anything - * particularly secret. If the user\'s home directory resides on an NFS - * volume where root is mapped to nobody, this may need to be world-readable. - */ -#define SSH_USER_CONFFILE ".ssh/config" - -/* - * File containing a list of those rsa keys that permit logging in as this - * user. This file need not be readable by anyone but the user him/herself, - * but does not contain anything particularly secret. If the user\'s home - * directory resides on an NFS volume where root is mapped to nobody, this - * may need to be world-readable. (This file is read by the daemon which is - * running as root.) - */ -#define SSH_USER_PERMITTED_KEYS ".ssh/authorized_keys" -#define SSH_USER_PERMITTED_KEYS2 ".ssh/authorized_keys2" - -/* - * Per-user and system-wide ssh "rc" files. These files are executed with - * /bin/sh before starting the shell or command if they exist. They will be - * passed "proto cookie" as arguments if X11 forwarding with spoofing is in - * use. xauth will be run if neither of these exists. - */ -#define SSH_USER_RC ".ssh/rc" -#define SSH_SYSTEM_RC ETCDIR "/sshrc" - -/* - * Ssh-only version of /etc/hosts.equiv. Additionally, the daemon may use - * ~/.rhosts and /etc/hosts.equiv if rhosts authentication is enabled. - */ -#define SSH_HOSTS_EQUIV ETCDIR "/shosts.equiv" - -/* - * Name of the environment variable containing the pathname of the - * authentication socket. - */ -#define SSH_AUTHSOCKET_ENV_NAME "SSH_AUTH_SOCK" +#define SSH_AGENTPID_ENV_NAME "SSH_AGENT_PID" /* * Name of the environment variable containing the pathname of the * authentication socket. */ -#define SSH_AGENTPID_ENV_NAME "SSH_AGENT_PID" +#define SSH_AUTHSOCKET_ENV_NAME "SSH_AUTH_SOCK" /* - * Default path to ssh-askpass used by ssh-add, - * environment variable for overwriting the default location + * Environment variable for overwriting the default location of askpass */ -#ifndef SSH_ASKPASS_DEFAULT -# define SSH_ASKPASS_DEFAULT "/usr/X11R6/bin/ssh-askpass" -#endif #define SSH_ASKPASS_ENV "SSH_ASKPASS" /* @@ -216,342 +83,20 @@ */ #define SSH_SESSION_KEY_LENGTH 32 -/* Name of Kerberos service for SSH to use. */ -#define KRB4_SERVICE_NAME "rcmd" - -/* - * Authentication methods. New types can be added, but old types should not - * be removed for compatibility. The maximum allowed value is 31. - */ -#define SSH_AUTH_RHOSTS 1 -#define SSH_AUTH_RSA 2 -#define SSH_AUTH_PASSWORD 3 -#define SSH_AUTH_RHOSTS_RSA 4 -#define SSH_AUTH_TIS 5 -#define SSH_AUTH_KERBEROS 6 -#define SSH_PASS_KERBEROS_TGT 7 - /* 8 to 15 are reserved */ -#define SSH_PASS_AFS_TOKEN 21 - -/* Protocol flags. These are bit masks. */ -#define SSH_PROTOFLAG_SCREEN_NUMBER 1 /* X11 forwarding includes screen */ -#define SSH_PROTOFLAG_HOST_IN_FWD_OPEN 2 /* forwarding opens contain host */ +/* Used to identify ``EscapeChar none'' */ +#define SSH_ESCAPECHAR_NONE -2 /* - * Definition of message types. New values can be added, but old values - * should not be removed or without careful consideration of the consequences - * for compatibility. The maximum value is 254; value 255 is reserved for - * future extension. + * unprivileged user when UsePrivilegeSeparation=yes; + * sshd will change its privileges to this user and its + * primary group. */ -/* Message name */ /* msg code */ /* arguments */ -#define SSH_MSG_NONE 0 /* no message */ -#define SSH_MSG_DISCONNECT 1 /* cause (string) */ -#define SSH_SMSG_PUBLIC_KEY 2 /* ck,msk,srvk,hostk */ -#define SSH_CMSG_SESSION_KEY 3 /* key (BIGNUM) */ -#define SSH_CMSG_USER 4 /* user (string) */ -#define SSH_CMSG_AUTH_RHOSTS 5 /* user (string) */ -#define SSH_CMSG_AUTH_RSA 6 /* modulus (BIGNUM) */ -#define SSH_SMSG_AUTH_RSA_CHALLENGE 7 /* int (BIGNUM) */ -#define SSH_CMSG_AUTH_RSA_RESPONSE 8 /* int (BIGNUM) */ -#define SSH_CMSG_AUTH_PASSWORD 9 /* pass (string) */ -#define SSH_CMSG_REQUEST_PTY 10 /* TERM, tty modes */ -#define SSH_CMSG_WINDOW_SIZE 11 /* row,col,xpix,ypix */ -#define SSH_CMSG_EXEC_SHELL 12 /* */ -#define SSH_CMSG_EXEC_CMD 13 /* cmd (string) */ -#define SSH_SMSG_SUCCESS 14 /* */ -#define SSH_SMSG_FAILURE 15 /* */ -#define SSH_CMSG_STDIN_DATA 16 /* data (string) */ -#define SSH_SMSG_STDOUT_DATA 17 /* data (string) */ -#define SSH_SMSG_STDERR_DATA 18 /* data (string) */ -#define SSH_CMSG_EOF 19 /* */ -#define SSH_SMSG_EXITSTATUS 20 /* status (int) */ -#define SSH_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* channel (int) */ -#define SSH_MSG_CHANNEL_OPEN_FAILURE 22 /* channel (int) */ -#define SSH_MSG_CHANNEL_DATA 23 /* ch,data (int,str) */ -#define SSH_MSG_CHANNEL_CLOSE 24 /* channel (int) */ -#define SSH_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* channel (int) */ -/* SSH_CMSG_X11_REQUEST_FORWARDING 26 OBSOLETE */ -#define SSH_SMSG_X11_OPEN 27 /* channel (int) */ -#define SSH_CMSG_PORT_FORWARD_REQUEST 28 /* p,host,hp (i,s,i) */ -#define SSH_MSG_PORT_OPEN 29 /* ch,h,p (i,s,i) */ -#define SSH_CMSG_AGENT_REQUEST_FORWARDING 30 /* */ -#define SSH_SMSG_AGENT_OPEN 31 /* port (int) */ -#define SSH_MSG_IGNORE 32 /* string */ -#define SSH_CMSG_EXIT_CONFIRMATION 33 /* */ -#define SSH_CMSG_X11_REQUEST_FORWARDING 34 /* proto,data (s,s) */ -#define SSH_CMSG_AUTH_RHOSTS_RSA 35 /* user,mod (s,mpi) */ -#define SSH_MSG_DEBUG 36 /* string */ -#define SSH_CMSG_REQUEST_COMPRESSION 37 /* level 1-9 (int) */ -#define SSH_CMSG_MAX_PACKET_SIZE 38 /* size 4k-1024k (int) */ -#define SSH_CMSG_AUTH_TIS 39 /* we use this for s/key */ -#define SSH_SMSG_AUTH_TIS_CHALLENGE 40 /* challenge (string) */ -#define SSH_CMSG_AUTH_TIS_RESPONSE 41 /* response (string) */ -#define SSH_CMSG_AUTH_KERBEROS 42 /* (KTEXT) */ -#define SSH_SMSG_AUTH_KERBEROS_RESPONSE 43 /* (KTEXT) */ -#define SSH_CMSG_HAVE_KERBEROS_TGT 44 /* credentials (s) */ -#define SSH_CMSG_HAVE_AFS_TOKEN 65 /* token (s) */ - -/*------------ 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. - */ -unsigned long -get_last_login_time(uid_t uid, const char *logname, - char *buf, unsigned 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, unsigned 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(const 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_DEBUG -} 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))); - -/* 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); - -/* 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); - -/* 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, unsigned char *buf, size_t buflen); -int radix_to_creds(const char *buf, CREDENTIALS * creds); -#endif /* AFS */ - -#endif /* KRB4 */ - -#ifdef SKEY -#include -char *skey_fake_keyinfo(char *username); -int auth_skey_password(struct passwd * pw, const char *password); -#endif /* SKEY */ - -/* AF_UNSPEC or AF_INET or AF_INET6 */ -extern int IPv4or6; +#ifndef SSH_PRIVSEP_USER +#define SSH_PRIVSEP_USER "sshd" +#endif -#ifdef USE_PAM -#include "auth-pam.h" -#endif /* USE_PAM */ +/* Minimum modulus size (n) for RSA keys. */ +#define SSH_RSA_MINIMUM_MODULUS_SIZE 768 -#endif /* SSH_H */ +/* Listen backlog for sshd, ssh-agent and forwarding sockets */ +#define SSH_LISTEN_BACKLOG 128