auth.h

   1 /* $OpenBSD: auth.h,v 1.58 2006/08/18 09:15:20 markus 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              force_pwchange;
  57         char            *user;          /* username sent by the client */
  58         char            *service;
  59         struct passwd   *pw;            /* set if 'valid' */
  60         char            *style;
  61         void            *kbdintctxt;
  62 #ifdef BSD_AUTH
  63         auth_session_t  *as;
  64 #endif
  65 #ifdef KRB5
  66         krb5_context     krb5_ctx;
  67         krb5_ccache      krb5_fwd_ccache;
  68         krb5_principal   krb5_user;
  69         char            *krb5_ticket_file;
  70         char            *krb5_ccname;
  71 #endif
  72         Buffer          *loginmsg;
  73         void            *methoddata;
  74 };
  75 /*
  76  * Every authentication method has to handle authentication requests for
  77  * non-existing users, or for users that are not allowed to login. In this
  78  * case 'valid' is set to 0, but 'user' points to the username requested by
  79  * the client.
  80  */
  81
  82 struct Authmethod {
  83         char    *name;
  84         int     (*userauth)(Authctxt *authctxt);
  85         int     *enabled;
  86 };
  87
  88 /*
  89  * Keyboard interactive device:
  90  * init_ctx     returns: non NULL upon success
  91  * query        returns: 0 - success, otherwise failure
  92  * respond      returns: 0 - success, 1 - need further interaction,
  93  *              otherwise - failure
  94  */
  95 struct KbdintDevice
  96 {
  97         const char *name;
  98         void*   (*init_ctx)(Authctxt*);
  99         int     (*query)(void *ctx, char **name, char **infotxt,
 100                     u_int *numprompts, char ***prompts, u_int **echo_on);
 101         int     (*respond)(void *ctx, u_int numresp, char **responses);
 102         void    (*free_ctx)(void *ctx);
 103 };
 104
 105 int      auth_rhosts(struct passwd *, const char *);
 106 int
 107 auth_rhosts2(struct passwd *, const char *, const char *, const char *);
 108
 109 int      auth_rhosts_rsa(Authctxt *, char *, Key *);
 110 int      auth_password(Authctxt *, const char *);
 111 int      auth_rsa(Authctxt *, BIGNUM *);
 112 int      auth_rsa_challenge_dialog(Key *);
 113 BIGNUM  *auth_rsa_generate_challenge(Key *);
 114 int      auth_rsa_verify_response(Key *, BIGNUM *, u_char[]);
 115 int      auth_rsa_key_allowed(struct passwd *, BIGNUM *, Key **);
 116
 117 int      auth_rhosts_rsa_key_allowed(struct passwd *, char *, char *, Key *);
 118 int      hostbased_key_allowed(struct passwd *, const char *, char *, Key *);
 119 int      user_key_allowed(struct passwd *, Key *);
 120
 121 #ifdef KRB5
 122 int     auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *);
 123 int     auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt);
 124 int     auth_krb5_password(Authctxt *authctxt, const char *password);
 125 void    krb5_cleanup_proc(Authctxt *authctxt);
 126 #endif /* KRB5 */
 127
 128 #if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
 129 #include <shadow.h>
 130 int auth_shadow_acctexpired(struct spwd *);
 131 int auth_shadow_pwexpired(Authctxt *);
 132 #endif
 133
 134 #include "auth-pam.h"
 135 #include "audit.h"
 136 void remove_kbdint_device(const char *);
 137
 138 void disable_forwarding(void);
 139
 140 void    do_authentication(Authctxt *);
 141 void    do_authentication2(Authctxt *);
 142
 143 void    auth_log(Authctxt *, int, char *, char *);
 144 void    userauth_finish(Authctxt *, int, char *);
 145 void    userauth_send_banner(const char *);
 146 int     auth_root_allowed(char *);
 147
 148 char    *auth2_read_banner(void);
 149
 150 void    privsep_challenge_enable(void);
 151
 152 int     auth2_challenge(Authctxt *, char *);
 153 void    auth2_challenge_stop(Authctxt *);
 154 int     bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **);
 155 int     bsdauth_respond(void *, u_int, char **);
 156 int     skey_query(void *, char **, char **, u_int *, char ***, u_int **);
 157 int     skey_respond(void *, u_int, char **);
 158
 159 int     allowed_user(struct passwd *);
 160 struct passwd * getpwnamallow(const char *user);
 161
 162 char    *get_challenge(Authctxt *);
 163 int     verify_response(Authctxt *, const char *);
 164 void    abandon_challenge_response(Authctxt *);
 165
 166 char    *authorized_keys_file(struct passwd *);
 167 char    *authorized_keys_file2(struct passwd *);
 168
 169 int
 170 secure_filename(FILE *, const char *, struct passwd *, char *, size_t);
 171
 172 HostStatus
 173 check_key_in_hostfiles(struct passwd *, Key *, const char *,
 174     const char *, const char *);
 175
 176 /* hostkey handling */
 177 Key     *get_hostkey_by_index(int);
 178 Key     *get_hostkey_by_type(int);
 179 int      get_hostkey_index(Key *);
 180 int      ssh1_session_key(BIGNUM *);
 181
 182 /* debug messages during authentication */
 183 void     auth_debug_add(const char *fmt,...) __attribute__((format(printf, 1, 2)));
 184 void     auth_debug_send(void);
 185 void     auth_debug_reset(void);
 186
 187 struct passwd *fakepw(void);
 188
 189 int      sys_auth_passwd(Authctxt *, const char *);
 190
 191 #define AUTH_FAIL_MSG "Too many authentication failures for %.100s"
 192
 193 #define SKEY_PROMPT "\nS/Key Password: "
 194
 195 #if defined(KRB5) && !defined(HEIMDAL)
 196 #include <krb5.h>
 197 krb5_error_code ssh_krb5_cc_gen(krb5_context, krb5_ccache *);
 198 #endif
 199 #endif