crypto/openssh/servconf.h

   1 /* $OpenBSD: servconf.h,v 1.126 2017/10/02 19:33:20 djm Exp $ */
   2
   3 /*
   4  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   5  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   6  *                    All rights reserved
   7  * Definitions for server configuration data and for the functions reading it.
   8  *
   9  * As far as I am concerned, the code I have written for this software
  10  * can be used freely for any purpose.  Any derived versions of this
  11  * software must be clearly marked as such, and if the derived work is
  12  * incompatible with the protocol description in the RFC file, it must be
  13  * called by a name other than "ssh" or "Secure Shell".
  14  */
  15
  16 #ifndef SERVCONF_H
  17 #define SERVCONF_H
  18
  19 #define MAX_PORTS               256     /* Max # ports. */
  20
  21 #define MAX_ALLOW_USERS         256     /* Max # users on allow list. */
  22 #define MAX_DENY_USERS          256     /* Max # users on deny list. */
  23 #define MAX_ALLOW_GROUPS        256     /* Max # groups on allow list. */
  24 #define MAX_DENY_GROUPS         256     /* Max # groups on deny list. */
  25 #define MAX_SUBSYSTEMS          256     /* Max # subsystems. */
  26 #define MAX_HOSTKEYS            256     /* Max # hostkeys. */
  27 #define MAX_HOSTCERTS           256     /* Max # host certificates. */
  28 #define MAX_ACCEPT_ENV          256     /* Max # of env vars. */
  29 #define MAX_MATCH_GROUPS        256     /* Max # of groups for Match. */
  30 #define MAX_AUTHKEYS_FILES      256     /* Max # of authorized_keys files. */
  31 #define MAX_AUTH_METHODS        256     /* Max # of AuthenticationMethods. */
  32
  33 /* permit_root_login */
  34 #define PERMIT_NOT_SET          -1
  35 #define PERMIT_NO               0
  36 #define PERMIT_FORCED_ONLY      1
  37 #define PERMIT_NO_PASSWD        2
  38 #define PERMIT_YES              3
  39
  40 /* use_privsep */
  41 #define PRIVSEP_OFF             0
  42 #define PRIVSEP_ON              1
  43 #define PRIVSEP_NOSANDBOX       2
  44
  45 /* AllowTCPForwarding */
  46 #define FORWARD_DENY            0
  47 #define FORWARD_REMOTE          (1)
  48 #define FORWARD_LOCAL           (1<<1)
  49 #define FORWARD_ALLOW           (FORWARD_REMOTE|FORWARD_LOCAL)
  50
  51 /* PermitOpen */
  52 #define PERMITOPEN_ANY          0
  53 #define PERMITOPEN_NONE         -2
  54
  55 #define DEFAULT_AUTH_FAIL_MAX   6       /* Default for MaxAuthTries */
  56 #define DEFAULT_SESSIONS_MAX    10      /* Default for MaxSessions */
  57
  58 /* Magic name for internal sftp-server */
  59 #define INTERNAL_SFTP_NAME      "internal-sftp"
  60
  61 struct ssh;
  62 struct fwd_perm_list;
  63
  64 typedef struct {
  65         u_int   num_ports;
  66         u_int   ports_from_cmdline;
  67         int     ports[MAX_PORTS];       /* Port number to listen on. */
  68         u_int   num_queued_listens;
  69         char   **queued_listen_addrs;
  70         int    *queued_listen_ports;
  71         struct addrinfo *listen_addrs;  /* Addresses on which the server listens. */
  72         int     address_family;         /* Address family used by the server. */
  73         char   *host_key_files[MAX_HOSTKEYS];   /* Files containing host keys. */
  74         int     num_host_key_files;     /* Number of files for host keys. */
  75         char   *host_cert_files[MAX_HOSTCERTS]; /* Files containing host certs. */
  76         int     num_host_cert_files;     /* Number of files for host certs. */
  77         char   *host_key_agent;          /* ssh-agent socket for host keys. */
  78         char   *pid_file;       /* Where to put our pid */
  79         int     login_grace_time;       /* Disconnect if no auth in this time
  80                                          * (sec). */
  81         int     permit_root_login;      /* PERMIT_*, see above */
  82         int     ignore_rhosts;  /* Ignore .rhosts and .shosts. */
  83         int     ignore_user_known_hosts;        /* Ignore ~/.ssh/known_hosts
  84                                                  * for RhostsRsaAuth */
  85         int     print_motd;     /* If true, print /etc/motd. */
  86         int     print_lastlog;  /* If true, print lastlog */
  87         int     x11_forwarding; /* If true, permit inet (spoofing) X11 fwd. */
  88         int     x11_display_offset;     /* What DISPLAY number to start
  89                                          * searching at */
  90         int     x11_use_localhost;      /* If true, use localhost for fake X11 server. */
  91         char   *xauth_location; /* Location of xauth program */
  92         int     permit_tty;     /* If false, deny pty allocation */
  93         int     permit_user_rc; /* If false, deny ~/.ssh/rc execution */
  94         int     strict_modes;   /* If true, require string home dir modes. */
  95         int     tcp_keep_alive; /* If true, set SO_KEEPALIVE. */
  96         int     ip_qos_interactive;     /* IP ToS/DSCP/class for interactive */
  97         int     ip_qos_bulk;            /* IP ToS/DSCP/class for bulk traffic */
  98         char   *ciphers;        /* Supported SSH2 ciphers. */
  99         char   *macs;           /* Supported SSH2 macs. */
 100         char   *kex_algorithms; /* SSH2 kex methods in order of preference. */
 101         struct ForwardOptions fwd_opts; /* forwarding options */
 102         SyslogFacility log_facility;    /* Facility for system logging. */
 103         LogLevel log_level;     /* Level for system logging. */
 104         int     hostbased_authentication;       /* If true, permit ssh2 hostbased auth */
 105         int     hostbased_uses_name_from_packet_only; /* experimental */
 106         char   *hostbased_key_types;    /* Key types allowed for hostbased */
 107         char   *hostkeyalgorithms;      /* SSH2 server key types */
 108         int     pubkey_authentication;  /* If true, permit ssh2 pubkey authentication. */
 109         char   *pubkey_key_types;       /* Key types allowed for public key */
 110         int     kerberos_authentication;        /* If true, permit Kerberos
 111                                                  * authentication. */
 112         int     kerberos_or_local_passwd;       /* If true, permit kerberos
 113                                                  * and any other password
 114                                                  * authentication mechanism,
 115                                                  * such as SecurID or
 116                                                  * /etc/passwd */
 117         int     kerberos_ticket_cleanup;        /* If true, destroy ticket
 118                                                  * file on logout. */
 119         int     kerberos_get_afs_token;         /* If true, try to get AFS token if
 120                                                  * authenticated with Kerberos. */
 121         int     gss_authentication;     /* If true, permit GSSAPI authentication */
 122         int     gss_cleanup_creds;      /* If true, destroy cred cache on logout */
 123         int     gss_strict_acceptor;    /* If true, restrict the GSSAPI acceptor name */
 124         int     password_authentication;        /* If true, permit password
 125                                                  * authentication. */
 126         int     kbd_interactive_authentication; /* If true, permit */
 127         int     challenge_response_authentication;
 128         int     permit_empty_passwd;    /* If false, do not permit empty
 129                                          * passwords. */
 130         int     permit_user_env;        /* If true, read ~/.ssh/environment */
 131         int     compression;    /* If true, compression is allowed */
 132         int     allow_tcp_forwarding; /* One of FORWARD_* */
 133         int     allow_streamlocal_forwarding; /* One of FORWARD_* */
 134         int     allow_agent_forwarding;
 135         int     disable_forwarding;
 136         u_int num_allow_users;
 137         char   *allow_users[MAX_ALLOW_USERS];
 138         u_int num_deny_users;
 139         char   *deny_users[MAX_DENY_USERS];
 140         u_int num_allow_groups;
 141         char   *allow_groups[MAX_ALLOW_GROUPS];
 142         u_int num_deny_groups;
 143         char   *deny_groups[MAX_DENY_GROUPS];
 144
 145         u_int num_subsystems;
 146         char   *subsystem_name[MAX_SUBSYSTEMS];
 147         char   *subsystem_command[MAX_SUBSYSTEMS];
 148         char   *subsystem_args[MAX_SUBSYSTEMS];
 149
 150         u_int num_accept_env;
 151         char   *accept_env[MAX_ACCEPT_ENV];
 152
 153         int     max_startups_begin;
 154         int     max_startups_rate;
 155         int     max_startups;
 156         int     max_authtries;
 157         int     max_sessions;
 158         char   *banner;                 /* SSH-2 banner message */
 159         int     use_dns;
 160         int     client_alive_interval;  /*
 161                                          * poke the client this often to
 162                                          * see if it's still there
 163                                          */
 164         int     client_alive_count_max; /*
 165                                          * If the client is unresponsive
 166                                          * for this many intervals above,
 167                                          * disconnect the session
 168                                          */
 169
 170         u_int num_authkeys_files;       /* Files containing public keys */
 171         char   *authorized_keys_files[MAX_AUTHKEYS_FILES];
 172
 173         char   *adm_forced_command;
 174
 175         int     use_pam;                /* Enable auth via PAM */
 176
 177         int     permit_tun;
 178
 179         char   **permitted_opens;
 180         u_int   num_permitted_opens; /* May also be one of PERMITOPEN_* */
 181
 182         char   *chroot_directory;
 183         char   *revoked_keys_file;
 184         char   *trusted_user_ca_keys;
 185         char   *authorized_keys_command;
 186         char   *authorized_keys_command_user;
 187         char   *authorized_principals_file;
 188         char   *authorized_principals_command;
 189         char   *authorized_principals_command_user;
 190
 191         int64_t rekey_limit;
 192         int     rekey_interval;
 193
 194         char   *version_addendum;       /* Appended to SSH banner */
 195
 196         u_int   num_auth_methods;
 197         char   *auth_methods[MAX_AUTH_METHODS];
 198
 199         int     fingerprint_hash;
 200         int     expose_userauth_info;
 201 }       ServerOptions;
 202
 203 /* Information about the incoming connection as used by Match */
 204 struct connection_info {
 205         const char *user;
 206         const char *host;       /* possibly resolved hostname */
 207         const char *address;    /* remote address */
 208         const char *laddress;   /* local address */
 209         int lport;              /* local port */
 210 };
 211
 212
 213 /*
 214  * These are string config options that must be copied between the
 215  * Match sub-config and the main config, and must be sent from the
 216  * privsep slave to the privsep master. We use a macro to ensure all
 217  * the options are copied and the copies are done in the correct order.
 218  *
 219  * NB. an option must appear in servconf.c:copy_set_server_options() or
 220  * COPY_MATCH_STRING_OPTS here but never both.
 221  */
 222 #define COPY_MATCH_STRING_OPTS() do { \
 223                 M_CP_STROPT(banner); \
 224                 M_CP_STROPT(trusted_user_ca_keys); \
 225                 M_CP_STROPT(revoked_keys_file); \
 226                 M_CP_STROPT(authorized_keys_command); \
 227                 M_CP_STROPT(authorized_keys_command_user); \
 228                 M_CP_STROPT(authorized_principals_file); \
 229                 M_CP_STROPT(authorized_principals_command); \
 230                 M_CP_STROPT(authorized_principals_command_user); \
 231                 M_CP_STROPT(hostbased_key_types); \
 232                 M_CP_STROPT(pubkey_key_types); \
 233                 M_CP_STRARRAYOPT(authorized_keys_files, num_authkeys_files); \
 234                 M_CP_STRARRAYOPT(allow_users, num_allow_users); \
 235                 M_CP_STRARRAYOPT(deny_users, num_deny_users); \
 236                 M_CP_STRARRAYOPT(allow_groups, num_allow_groups); \
 237                 M_CP_STRARRAYOPT(deny_groups, num_deny_groups); \
 238                 M_CP_STRARRAYOPT(accept_env, num_accept_env); \
 239                 M_CP_STRARRAYOPT(auth_methods, num_auth_methods); \
 240                 M_CP_STRARRAYOPT_ALLOC(permitted_opens, num_permitted_opens); \
 241         } while (0)
 242
 243 struct connection_info *get_connection_info(int, int);
 244 void     initialize_server_options(ServerOptions *);
 245 void     fill_default_server_options(ServerOptions *);
 246 int      process_server_config_line(ServerOptions *, char *, const char *, int,
 247              int *, struct connection_info *);
 248 void     process_permitopen(struct ssh *ssh, ServerOptions *options);
 249 void     load_server_config(const char *, Buffer *);
 250 void     parse_server_config(ServerOptions *, const char *, Buffer *,
 251              struct connection_info *);
 252 void     parse_server_match_config(ServerOptions *, struct connection_info *);
 253 int      parse_server_match_testspec(struct connection_info *, char *);
 254 int      server_match_spec_complete(struct connection_info *);
 255 void     copy_set_server_options(ServerOptions *, ServerOptions *, int);
 256 void     dump_config(ServerOptions *);
 257 char    *derelativise_path(const char *);
 258
 259 #endif                          /* SERVCONF_H */