crypto/openssh/auth.h

   1 /* $OpenBSD: auth.h,v 1.88 2016/05/04 14:04:40 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 struct ssh;
  46 struct sshkey;
  47
  48 typedef struct Authctxt Authctxt;
  49 typedef struct Authmethod Authmethod;
  50 typedef struct KbdintDevice KbdintDevice;
  51
  52 struct Authctxt {
  53         sig_atomic_t     success;
  54         int              authenticated; /* authenticated and alarms cancelled */
  55         int              postponed;     /* authentication needs another step */
  56         int              valid;         /* user exists and is allowed to login */
  57         int              attempt;
  58         int              failures;
  59         int              server_caused_failure;
  60         int              force_pwchange;
  61         char            *user;          /* username sent by the client */
  62         char            *service;
  63         struct passwd   *pw;            /* set if 'valid' */
  64         char            *style;
  65         void            *kbdintctxt;
  66         char            *info;          /* Extra info for next auth_log */
  67 #ifdef BSD_AUTH
  68         auth_session_t  *as;
  69 #endif
  70         char            **auth_methods; /* modified from server config */
  71         u_int            num_auth_methods;
  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         struct sshkey   **prev_userkeys;
  83         u_int            nprev_userkeys;
  84 };
  85 /*
  86  * Every authentication method has to handle authentication requests for
  87  * non-existing users, or for users that are not allowed to login. In this
  88  * case 'valid' is set to 0, but 'user' points to the username requested by
  89  * the client.
  90  */
  91
  92 struct Authmethod {
  93         char    *name;
  94         int     (*userauth)(Authctxt *authctxt);
  95         int     *enabled;
  96 };
  97
  98 /*
  99  * Keyboard interactive device:
 100  * init_ctx     returns: non NULL upon success
 101  * query        returns: 0 - success, otherwise failure
 102  * respond      returns: 0 - success, 1 - need further interaction,
 103  *              otherwise - failure
 104  */
 105 struct KbdintDevice
 106 {
 107         const char *name;
 108         void*   (*init_ctx)(Authctxt*);
 109         int     (*query)(void *ctx, char **name, char **infotxt,
 110                     u_int *numprompts, char ***prompts, u_int **echo_on);
 111         int     (*respond)(void *ctx, u_int numresp, char **responses);
 112         void    (*free_ctx)(void *ctx);
 113 };
 114
 115 int      auth_rhosts(struct passwd *, const char *);
 116 int
 117 auth_rhosts2(struct passwd *, const char *, const char *, const char *);
 118
 119 int      auth_rhosts_rsa(Authctxt *, char *, Key *);
 120 int      auth_password(Authctxt *, const char *);
 121 int      auth_rsa(Authctxt *, BIGNUM *);
 122 int      auth_rsa_challenge_dialog(Key *);
 123 BIGNUM  *auth_rsa_generate_challenge(Key *);
 124 int      auth_rsa_verify_response(Key *, BIGNUM *, u_char[]);
 125 int      auth_rsa_key_allowed(struct passwd *, BIGNUM *, Key **);
 126
 127 int      auth_rhosts_rsa_key_allowed(struct passwd *, const char *,
 128     const char *, Key *);
 129 int      hostbased_key_allowed(struct passwd *, const char *, char *, Key *);
 130 int      user_key_allowed(struct passwd *, Key *, int);
 131 void     pubkey_auth_info(Authctxt *, const Key *, const char *, ...)
 132             __attribute__((__format__ (printf, 3, 4)));
 133 void     auth2_record_userkey(Authctxt *, struct sshkey *);
 134 int      auth2_userkey_already_used(Authctxt *, struct sshkey *);
 135
 136 struct stat;
 137 int      auth_secure_path(const char *, struct stat *, const char *, uid_t,
 138     char *, size_t);
 139
 140 #ifdef KRB5
 141 int     auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *);
 142 int     auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt);
 143 int     auth_krb5_password(Authctxt *authctxt, const char *password);
 144 void    krb5_cleanup_proc(Authctxt *authctxt);
 145 #endif /* KRB5 */
 146
 147 #if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
 148 #include <shadow.h>
 149 int auth_shadow_acctexpired(struct spwd *);
 150 int auth_shadow_pwexpired(Authctxt *);
 151 #endif
 152
 153 #include "auth-pam.h"
 154 #include "audit.h"
 155 void remove_kbdint_device(const char *);
 156
 157 void disable_forwarding(void);
 158
 159 void    do_authentication(Authctxt *);
 160 void    do_authentication2(Authctxt *);
 161
 162 void    auth_info(Authctxt *authctxt, const char *, ...)
 163             __attribute__((__format__ (printf, 2, 3)))
 164             __attribute__((__nonnull__ (2)));
 165 void    auth_log(Authctxt *, int, int, const char *, const char *);
 166 void    auth_maxtries_exceeded(Authctxt *) __attribute__((noreturn));
 167 void    userauth_finish(Authctxt *, int, const char *, const char *);
 168 int     auth_root_allowed(const char *);
 169
 170 void    userauth_send_banner(const char *);
 171
 172 char    *auth2_read_banner(void);
 173 int      auth2_methods_valid(const char *, int);
 174 int      auth2_update_methods_lists(Authctxt *, const char *, const char *);
 175 int      auth2_setup_methods_lists(Authctxt *);
 176 int      auth2_method_allowed(Authctxt *, const char *, const char *);
 177
 178 void    privsep_challenge_enable(void);
 179
 180 int     auth2_challenge(Authctxt *, char *);
 181 void    auth2_challenge_stop(Authctxt *);
 182 int     bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **);
 183 int     bsdauth_respond(void *, u_int, char **);
 184 int     skey_query(void *, char **, char **, u_int *, char ***, u_int **);
 185 int     skey_respond(void *, u_int, char **);
 186
 187 int     allowed_user(struct passwd *);
 188 struct passwd * getpwnamallow(const char *user);
 189
 190 char    *get_challenge(Authctxt *);
 191 int     verify_response(Authctxt *, const char *);
 192 void    abandon_challenge_response(Authctxt *);
 193
 194 char    *expand_authorized_keys(const char *, struct passwd *pw);
 195 char    *authorized_principals_file(struct passwd *);
 196
 197 FILE    *auth_openkeyfile(const char *, struct passwd *, int);
 198 FILE    *auth_openprincipals(const char *, struct passwd *, int);
 199 int      auth_key_is_revoked(Key *);
 200
 201 const char      *auth_get_canonical_hostname(struct ssh *, int);
 202
 203 HostStatus
 204 check_key_in_hostfiles(struct passwd *, Key *, const char *,
 205     const char *, const char *);
 206
 207 /* hostkey handling */
 208 Key     *get_hostkey_by_index(int);
 209 Key     *get_hostkey_public_by_index(int, struct ssh *);
 210 Key     *get_hostkey_public_by_type(int, int, struct ssh *);
 211 Key     *get_hostkey_private_by_type(int, int, struct ssh *);
 212 int      get_hostkey_index(Key *, int, struct ssh *);
 213 int      ssh1_session_key(BIGNUM *);
 214 int      sshd_hostkey_sign(Key *, Key *, u_char **, size_t *,
 215              const u_char *, size_t, const char *, u_int);
 216
 217 /* debug messages during authentication */
 218 void     auth_debug_add(const char *fmt,...) __attribute__((format(printf, 1, 2)));
 219 void     auth_debug_send(void);
 220 void     auth_debug_reset(void);
 221
 222 struct passwd *fakepw(void);
 223
 224 int      sys_auth_passwd(Authctxt *, const char *);
 225
 226 #define SKEY_PROMPT "\nS/Key Password: "
 227
 228 #if defined(KRB5) && !defined(HEIMDAL)
 229 #include <krb5.h>
 230 krb5_error_code ssh_krb5_cc_gen(krb5_context, krb5_ccache *);
 231 #endif
 232 #endif