1 /* $OpenBSD: auth.h,v 1.77 2014/01/29 06:18:35 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 userauth_finish(Authctxt *, int, const char *, const char *); 158 int auth_root_allowed(const char *); 159 160 void userauth_send_banner(const char *); 161 162 char *auth2_read_banner(void); 163 int auth2_methods_valid(const char *, int); 164 int auth2_update_methods_lists(Authctxt *, const char *, const char *); 165 int auth2_setup_methods_lists(Authctxt *); 166 int auth2_method_allowed(Authctxt *, const char *, const char *); 167 168 void privsep_challenge_enable(void); 169 170 int auth2_challenge(Authctxt *, char *); 171 void auth2_challenge_stop(Authctxt *); 172 int bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **); 173 int bsdauth_respond(void *, u_int, char **); 174 int skey_query(void *, char **, char **, u_int *, char ***, u_int **); 175 int skey_respond(void *, u_int, char **); 176 177 int allowed_user(struct passwd *); 178 struct passwd * getpwnamallow(const char *user); 179 180 char *get_challenge(Authctxt *); 181 int verify_response(Authctxt *, const char *); 182 void abandon_challenge_response(Authctxt *); 183 184 char *expand_authorized_keys(const char *, struct passwd *pw); 185 char *authorized_principals_file(struct passwd *); 186 187 FILE *auth_openkeyfile(const char *, struct passwd *, int); 188 FILE *auth_openprincipals(const char *, struct passwd *, int); 189 int auth_key_is_revoked(Key *); 190 191 HostStatus 192 check_key_in_hostfiles(struct passwd *, Key *, const char *, 193 const char *, const char *); 194 195 /* hostkey handling */ 196 Key *get_hostkey_by_index(int); 197 Key *get_hostkey_public_by_index(int); 198 Key *get_hostkey_public_by_type(int); 199 Key *get_hostkey_private_by_type(int); 200 int get_hostkey_index(Key *); 201 int ssh1_session_key(BIGNUM *); 202 void sshd_hostkey_sign(Key *, Key *, u_char **, u_int *, u_char *, u_int); 203 204 /* debug messages during authentication */ 205 void auth_debug_add(const char *fmt,...) __attribute__((format(printf, 1, 2))); 206 void auth_debug_send(void); 207 void auth_debug_reset(void); 208 209 struct passwd *fakepw(void); 210 211 int sys_auth_passwd(Authctxt *, const char *); 212 213 #define AUTH_FAIL_MSG "Too many authentication failures for %.100s" 214 215 #define SKEY_PROMPT "\nS/Key Password: " 216 217 #if defined(KRB5) && !defined(HEIMDAL) 218 #include <krb5.h> 219 krb5_error_code ssh_krb5_cc_gen(krb5_context, krb5_ccache *); 220 #endif 221 #endif 222