crypto/openssh/auth.h

   1 /* $OpenBSD: auth.h,v 1.78 2014/07/03 11:16:55 djm Exp $ */
   2
   3 /*
   4  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  *
  26  */
  27
  28 #ifndef AUTH_H
  29 #define AUTH_H
  30
  31 #include <signal.h>
  32
  33 #include <openssl/rsa.h>
  34
  35 #ifdef HAVE_LOGIN_CAP
  36 #include <login_cap.h>
  37 #endif
  38 #ifdef BSD_AUTH
  39 #include <bsd_auth.h>
  40 #endif
  41 #ifdef KRB5
  42 #include <krb5.h>
  43 #endif
  44
  45 typedef struct Authctxt Authctxt;
  46 typedef struct Authmethod Authmethod;
  47 typedef struct KbdintDevice KbdintDevice;
  48
  49 struct Authctxt {
  50         sig_atomic_t     success;
  51         int              authenticated; /* authenticated and alarms cancelled */
  52         int              postponed;     /* authentication needs another step */
  53         int              valid;         /* user exists and is allowed to login */
  54         int              attempt;
  55         int              failures;
  56         int              server_caused_failure;
  57         int              force_pwchange;
  58         char            *user;          /* username sent by the client */
  59         char            *service;
  60         struct passwd   *pw;            /* set if 'valid' */
  61         char            *style;
  62         void            *kbdintctxt;
  63         char            *info;          /* Extra info for next auth_log */
  64 #ifdef BSD_AUTH
  65         auth_session_t  *as;
  66 #endif
  67         char            **auth_methods; /* modified from server config */
  68         u_int            num_auth_methods;
  69 #ifdef KRB5
  70         krb5_context     krb5_ctx;
  71         krb5_ccache      krb5_fwd_ccache;
  72         krb5_principal   krb5_user;
  73         char            *krb5_ticket_file;
  74         char            *krb5_ccname;
  75 #endif
  76         Buffer          *loginmsg;
  77         void            *methoddata;
  78 };
  79 /*
  80  * Every authentication method has to handle authentication requests for
  81  * non-existing users, or for users that are not allowed to login. In this
  82  * case 'valid' is set to 0, but 'user' points to the username requested by
  83  * the client.
  84  */
  85
  86 struct Authmethod {
  87         char    *name;
  88         int     (*userauth)(Authctxt *authctxt);
  89         int     *enabled;
  90 };
  91
  92 /*
  93  * Keyboard interactive device:
  94  * init_ctx     returns: non NULL upon success
  95  * query        returns: 0 - success, otherwise failure
  96  * respond      returns: 0 - success, 1 - need further interaction,
  97  *              otherwise - failure
  98  */
  99 struct KbdintDevice
 100 {
 101         const char *name;
 102         void*   (*init_ctx)(Authctxt*);
 103         int     (*query)(void *ctx, char **name, char **infotxt,
 104                     u_int *numprompts, char ***prompts, u_int **echo_on);
 105         int     (*respond)(void *ctx, u_int numresp, char **responses);
 106         void    (*free_ctx)(void *ctx);
 107 };
 108
 109 int      auth_rhosts(struct passwd *, const char *);
 110 int
 111 auth_rhosts2(struct passwd *, const char *, const char *, const char *);
 112
 113 int      auth_rhosts_rsa(Authctxt *, char *, Key *);
 114 int      auth_password(Authctxt *, const char *);
 115 int      auth_rsa(Authctxt *, BIGNUM *);
 116 int      auth_rsa_challenge_dialog(Key *);
 117 BIGNUM  *auth_rsa_generate_challenge(Key *);
 118 int      auth_rsa_verify_response(Key *, BIGNUM *, u_char[]);
 119 int      auth_rsa_key_allowed(struct passwd *, BIGNUM *, Key **);
 120
 121 int      auth_rhosts_rsa_key_allowed(struct passwd *, char *, char *, Key *);
 122 int      hostbased_key_allowed(struct passwd *, const char *, char *, Key *);
 123 int      user_key_allowed(struct passwd *, Key *);
 124 void     pubkey_auth_info(Authctxt *, const Key *, const char *, ...)
 125             __attribute__((__format__ (printf, 3, 4)));
 126
 127 struct stat;
 128 int      auth_secure_path(const char *, struct stat *, const char *, uid_t,
 129     char *, size_t);
 130
 131 #ifdef KRB5
 132 int     auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *);
 133 int     auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt);
 134 int     auth_krb5_password(Authctxt *authctxt, const char *password);
 135 void    krb5_cleanup_proc(Authctxt *authctxt);
 136 #endif /* KRB5 */
 137
 138 #if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
 139 #include <shadow.h>
 140 int auth_shadow_acctexpired(struct spwd *);
 141 int auth_shadow_pwexpired(Authctxt *);
 142 #endif
 143
 144 #include "auth-pam.h"
 145 #include "audit.h"
 146 void remove_kbdint_device(const char *);
 147
 148 void disable_forwarding(void);
 149
 150 void    do_authentication(Authctxt *);
 151 void    do_authentication2(Authctxt *);
 152
 153 void    auth_info(Authctxt *authctxt, const char *, ...)
 154             __attribute__((__format__ (printf, 2, 3)))
 155             __attribute__((__nonnull__ (2)));
 156 void    auth_log(Authctxt *, int, int, const char *, const char *);
 157 void    auth_maxtries_exceeded(Authctxt *) __attribute__((noreturn));
 158 void    userauth_finish(Authctxt *, int, const char *, const char *);
 159 int     auth_root_allowed(const char *);
 160
 161 void    userauth_send_banner(const char *);
 162
 163 char    *auth2_read_banner(void);
 164 int      auth2_methods_valid(const char *, int);
 165 int      auth2_update_methods_lists(Authctxt *, const char *, const char *);
 166 int      auth2_setup_methods_lists(Authctxt *);
 167 int      auth2_method_allowed(Authctxt *, const char *, const char *);
 168
 169 void    privsep_challenge_enable(void);
 170
 171 int     auth2_challenge(Authctxt *, char *);
 172 void    auth2_challenge_stop(Authctxt *);
 173 int     bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **);
 174 int     bsdauth_respond(void *, u_int, char **);
 175 int     skey_query(void *, char **, char **, u_int *, char ***, u_int **);
 176 int     skey_respond(void *, u_int, char **);
 177
 178 int     allowed_user(struct passwd *);
 179 struct passwd * getpwnamallow(const char *user);
 180
 181 char    *get_challenge(Authctxt *);
 182 int     verify_response(Authctxt *, const char *);
 183 void    abandon_challenge_response(Authctxt *);
 184
 185 char    *expand_authorized_keys(const char *, struct passwd *pw);
 186 char    *authorized_principals_file(struct passwd *);
 187
 188 FILE    *auth_openkeyfile(const char *, struct passwd *, int);
 189 FILE    *auth_openprincipals(const char *, struct passwd *, int);
 190 int      auth_key_is_revoked(Key *);
 191
 192 HostStatus
 193 check_key_in_hostfiles(struct passwd *, Key *, const char *,
 194     const char *, const char *);
 195
 196 /* hostkey handling */
 197 Key     *get_hostkey_by_index(int);
 198 Key     *get_hostkey_public_by_index(int);
 199 Key     *get_hostkey_public_by_type(int);
 200 Key     *get_hostkey_private_by_type(int);
 201 int      get_hostkey_index(Key *);
 202 int      ssh1_session_key(BIGNUM *);
 203 void     sshd_hostkey_sign(Key *, Key *, u_char **, u_int *, u_char *, u_int);
 204
 205 /* debug messages during authentication */
 206 void     auth_debug_add(const char *fmt,...) __attribute__((format(printf, 1, 2)));
 207 void     auth_debug_send(void);
 208 void     auth_debug_reset(void);
 209
 210 struct passwd *fakepw(void);
 211
 212 int      sys_auth_passwd(Authctxt *, const char *);
 213
 214 #define SKEY_PROMPT "\nS/Key Password: "
 215
 216 #if defined(KRB5) && !defined(HEIMDAL)
 217 #include <krb5.h>
 218 krb5_error_code ssh_krb5_cc_gen(krb5_context, krb5_ccache *);
 219 #endif
 220 #endif