+/* $OpenBSD: ssh.h,v 1.78 2006/08/03 03:34:42 deraadt Exp $ */
+
/*
- *
- * ssh.h
- *
* Author: Tatu Ylonen <ylo@cs.hut.fi>
- *
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, 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 <netinet/in.h> /* For struct sockaddr_in */
-#include <pwd.h> /* For struct pw */
-#include <stdarg.h> /* For va_list */
-#include <sys/socket.h> /* For struct sockaddr_storage */
-#include "fake-socket.h" /* For struct sockaddr_storage */
-#ifdef HAVE_SYS_SELECT_H
-# include <sys/select.h>
-#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
#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
*/
#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"
/*
*/
#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 <krb.h>
-/*
- * 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 <kafs.h>
-
-/* 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 <skey.h>
-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
andersk / openssh.git / blobdiff