auth.h

   1 /* $OpenBSD: auth.h,v 1.55 2006/07/23 01:11:05 stevesk 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 <sys/types.h>
  32
  33 #include <signal.h>
  34 #include <pwd.h>
  35 #include <signal.h>
  36
  37 #include "buffer.h"
  38 #include <openssl/rsa.h>
  39
  40 #ifdef HAVE_LOGIN_CAP
  41 #include <login_cap.h>
  42 #endif
  43 #ifdef BSD_AUTH
  44 #include <bsd_auth.h>
  45 #endif
  46 #ifdef KRB5
  47 #include <krb5.h>
  48 #endif
  49
  50 #include "key.h"
  51 #include "hostfile.h"
  52
  53 typedef struct Authctxt Authctxt;
  54 typedef struct Authmethod Authmethod;
  55 typedef struct KbdintDevice KbdintDevice;
  56
  57 struct Authctxt {
  58         sig_atomic_t     success;
  59         int              postponed;     /* authentication needs another step */
  60         int              valid;         /* user exists and is allowed to login */
  61         int              attempt;
  62         int              failures;
  63         int              force_pwchange;
  64         char            *user;          /* username sent by the client */
  65         char            *service;
  66         struct passwd   *pw;            /* set if 'valid' */
  67         char            *style;
  68         void            *kbdintctxt;
  69 #ifdef BSD_AUTH
  70         auth_session_t  *as;
  71 #endif
  72 #ifdef KRB5
  73         krb5_context     krb5_ctx;
  74         krb5_ccache      krb5_fwd_ccache;
  75         krb5_principal   krb5_user;
  76         char            *krb5_ticket_file;
  77         char            *krb5_ccname;
  78 #endif
  79         Buffer          *loginmsg;
  80         void            *methoddata;
  81 };
  82 /*
  83  * Every authentication method has to handle authentication requests for
  84  * non-existing users, or for users that are not allowed to login. In this
  85  * case 'valid' is set to 0, but 'user' points to the username requested by
  86  * the client.
  87  */
  88
  89 struct Authmethod {
  90         char    *name;
  91         int     (*userauth)(Authctxt *authctxt);
  92         int     *enabled;
  93 };
  94
  95 /*
  96  * Keyboard interactive device:
  97  * init_ctx     returns: non NULL upon success
  98  * query        returns: 0 - success, otherwise failure
  99  * respond      returns: 0 - success, 1 - need further interaction,
 100  *              otherwise - failure
 101  */
 102 struct KbdintDevice
 103 {
 104         const char *name;
 105         void*   (*init_ctx)(Authctxt*);
 106         int     (*query)(void *ctx, char **name, char **infotxt,
 107                     u_int *numprompts, char ***prompts, u_int **echo_on);
 108         int     (*respond)(void *ctx, u_int numresp, char **responses);
 109         void    (*free_ctx)(void *ctx);
 110 };
 111
 112 int      auth_rhosts(struct passwd *, const char *);
 113 int
 114 auth_rhosts2(struct passwd *, const char *, const char *, const char *);
 115
 116 int      auth_rhosts_rsa(Authctxt *, char *, Key *);
 117 int      auth_password(Authctxt *, const char *);
 118 int      auth_rsa(Authctxt *, BIGNUM *);
 119 int      auth_rsa_challenge_dialog(Key *);
 120 BIGNUM  *auth_rsa_generate_challenge(Key *);
 121 int      auth_rsa_verify_response(Key *, BIGNUM *, u_char[]);
 122 int      auth_rsa_key_allowed(struct passwd *, BIGNUM *, Key **);
 123
 124 int      auth_rhosts_rsa_key_allowed(struct passwd *, char *, char *, Key *);
 125 int      hostbased_key_allowed(struct passwd *, const char *, char *, Key *);
 126 int      user_key_allowed(struct passwd *, Key *);
 127
 128 #ifdef KRB5
 129 int     auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *);
 130 int     auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt);
 131 int     auth_krb5_password(Authctxt *authctxt, const char *password);
 132 void    krb5_cleanup_proc(Authctxt *authctxt);
 133 #endif /* KRB5 */
 134
 135 #if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
 136 #include <shadow.h>
 137 int auth_shadow_acctexpired(struct spwd *);
 138 int auth_shadow_pwexpired(Authctxt *);
 139 #endif
 140
 141 #include "auth-pam.h"
 142 #include "audit.h"
 143 void remove_kbdint_device(const char *);
 144
 145 void disable_forwarding(void);
 146
 147 void    do_authentication(Authctxt *);
 148 void    do_authentication2(Authctxt *);
 149
 150 void    auth_log(Authctxt *, int, char *, char *);
 151 void    userauth_finish(Authctxt *, int, char *);
 152 void    userauth_send_banner(const char *);
 153 int     auth_root_allowed(char *);
 154
 155 char    *auth2_read_banner(void);
 156
 157 void    privsep_challenge_enable(void);
 158
 159 int     auth2_challenge(Authctxt *, char *);
 160 void    auth2_challenge_stop(Authctxt *);
 161 int     bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **);
 162 int     bsdauth_respond(void *, u_int, char **);
 163 int     skey_query(void *, char **, char **, u_int *, char ***, u_int **);
 164 int     skey_respond(void *, u_int, char **);
 165
 166 int     allowed_user(struct passwd *);
 167 struct passwd * getpwnamallow(const char *user);
 168
 169 char    *get_challenge(Authctxt *);
 170 int     verify_response(Authctxt *, const char *);
 171 void    abandon_challenge_response(Authctxt *);
 172
 173 char    *authorized_keys_file(struct passwd *);
 174 char    *authorized_keys_file2(struct passwd *);
 175
 176 int
 177 secure_filename(FILE *, const char *, struct passwd *, char *, size_t);
 178
 179 HostStatus
 180 check_key_in_hostfiles(struct passwd *, Key *, const char *,
 181     const char *, const char *);
 182
 183 /* hostkey handling */
 184 Key     *get_hostkey_by_index(int);
 185 Key     *get_hostkey_by_type(int);
 186 int      get_hostkey_index(Key *);
 187 int      ssh1_session_key(BIGNUM *);
 188
 189 /* debug messages during authentication */
 190 void     auth_debug_add(const char *fmt,...) __attribute__((format(printf, 1, 2)));
 191 void     auth_debug_send(void);
 192 void     auth_debug_reset(void);
 193
 194 struct passwd *fakepw(void);
 195
 196 int      sys_auth_passwd(Authctxt *, const char *);
 197
 198 #define AUTH_FAIL_MSG "Too many authentication failures for %.100s"
 199
 200 #define SKEY_PROMPT "\nS/Key Password: "
 201
 202 #if defined(KRB5) && !defined(HEIMDAL)
 203 #include <krb5.h>
 204 krb5_error_code ssh_krb5_cc_gen(krb5_context, krb5_ccache *);
 205 #endif
 206 #endif