1 /* $NetBSD: auth.h,v 1.12 2016/03/11 01:55:00 christos Exp $ */ 2 /* $OpenBSD: auth.h,v 1.86 2015/12/04 16:41:28 markus Exp $ */ 3 4 /* 5 * Copyright (c) 2000 Markus Friedl. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 * 27 */ 28 29 #ifndef AUTH_H 30 #define AUTH_H 31 32 #include <signal.h> 33 34 #include <openssl/rsa.h> 35 36 #ifdef HAVE_LOGIN_CAP 37 #include <login_cap.h> 38 #endif 39 #ifdef BSD_AUTH 40 #include <bsd_auth.h> 41 #endif 42 #ifdef KRB5 43 #include <krb5.h> 44 #endif 45 46 struct ssh; 47 struct sshkey; 48 49 typedef struct Authctxt Authctxt; 50 typedef struct Authmethod Authmethod; 51 typedef struct KbdintDevice KbdintDevice; 52 53 struct Authctxt { 54 sig_atomic_t success; 55 int authenticated; /* authenticated and alarms cancelled */ 56 int postponed; /* authentication needs another step */ 57 int valid; /* user exists and is allowed to login */ 58 int attempt; 59 int failures; 60 int server_caused_failure; 61 int force_pwchange; 62 char *user; /* username sent by the client */ 63 char *service; 64 struct passwd *pw; /* set if 'valid' */ 65 char *style; 66 void *kbdintctxt; 67 char *info; /* Extra info for next auth_log */ 68 #ifdef BSD_AUTH 69 auth_session_t *as; 70 #endif 71 #ifdef KRB4 72 char *krb4_ticket_file; 73 #endif 74 char **auth_methods; /* modified from server config */ 75 u_int num_auth_methods; 76 #ifdef KRB5 77 krb5_context krb5_ctx; 78 krb5_auth_context krb5_auth_ctx; 79 krb5_ccache krb5_fwd_ccache; 80 krb5_principal krb5_user; 81 char *krb5_ticket_file; 82 #endif 83 void *methoddata; 84 85 struct sshkey **prev_userkeys; 86 u_int nprev_userkeys; 87 }; 88 /* 89 * Every authentication method has to handle authentication requests for 90 * non-existing users, or for users that are not allowed to login. In this 91 * case 'valid' is set to 0, but 'user' points to the username requested by 92 * the client. 93 */ 94 95 #ifdef USE_PAM 96 #include "auth-pam.h" 97 #endif 98 99 struct Authmethod { 100 const char *name; 101 int (*userauth)(Authctxt *authctxt); 102 int *enabled; 103 }; 104 105 /* 106 * Keyboard interactive device: 107 * init_ctx returns: non NULL upon success 108 * query returns: 0 - success, otherwise failure 109 * respond returns: 0 - success, 1 - need further interaction, 110 * otherwise - failure 111 */ 112 struct KbdintDevice 113 { 114 const char *name; 115 void* (*init_ctx)(Authctxt*); 116 int (*query)(void *ctx, char **name, char **infotxt, 117 u_int *numprompts, char ***prompts, u_int **echo_on); 118 int (*respond)(void *ctx, u_int numresp, char **responses); 119 void (*free_ctx)(void *ctx); 120 }; 121 122 void disable_forwarding(void); 123 int auth_rhosts(struct passwd *, const char *); 124 int 125 auth_rhosts2(struct passwd *, const char *, const char *, const char *); 126 127 int auth_rhosts_rsa(Authctxt *, char *, Key *); 128 int auth_password(Authctxt *, const char *); 129 int auth_rsa(Authctxt *, BIGNUM *); 130 int auth_rsa_challenge_dialog(Key *); 131 BIGNUM *auth_rsa_generate_challenge(Key *); 132 int auth_rsa_verify_response(Key *, BIGNUM *, u_char[]); 133 int auth_rsa_key_allowed(struct passwd *, BIGNUM *, Key **); 134 135 int auth_rhosts_rsa_key_allowed(struct passwd *, char *, char *, Key *); 136 int hostbased_key_allowed(struct passwd *, const char *, char *, Key *); 137 int user_key_allowed(struct passwd *, Key *, int); 138 void pubkey_auth_info(Authctxt *, const Key *, const char *, ...) 139 __attribute__((__format__ (printf, 3, 4))); 140 void auth2_record_userkey(Authctxt *, struct sshkey *); 141 int auth2_userkey_already_used(Authctxt *, struct sshkey *); 142 143 #ifdef KRB4 144 #include <krb.h> 145 int auth_krb4(Authctxt *, KTEXT, char **, KTEXT); 146 int auth_krb4_password(Authctxt *, const char *); 147 void krb4_cleanup_proc(void *); 148 149 #ifdef AFS 150 #include <kafs.h> 151 int auth_krb4_tgt(Authctxt *, const char *); 152 int auth_afs_token(Authctxt *, const char *); 153 #endif /* AFS */ 154 155 #endif /* KRB4 */ 156 157 struct stat; 158 int auth_secure_path(const char *, struct stat *, const char *, uid_t, 159 char *, size_t); 160 161 #ifdef KRB5 162 int auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *); 163 int auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt); 164 int auth_krb5_password(Authctxt *authctxt, const char *password); 165 void krb5_cleanup_proc(Authctxt *authctxt); 166 #endif /* KRB5 */ 167 168 void do_authentication(Authctxt *); 169 void do_authentication2(Authctxt *); 170 171 void auth_info(Authctxt *authctxt, const char *, ...) 172 __attribute__((__format__ (printf, 2, 3))) 173 __attribute__((__nonnull__ (2))); 174 void auth_log(Authctxt *, int, int, const char *, const char *); 175 void auth_maxtries_exceeded(Authctxt *) __attribute__((noreturn)); 176 void userauth_finish(Authctxt *, int, const char *, const char *); 177 int auth_root_allowed(const char *); 178 179 char *auth2_read_banner(void); 180 int auth2_methods_valid(const char *, int); 181 int auth2_update_methods_lists(Authctxt *, const char *, const char *); 182 int auth2_setup_methods_lists(Authctxt *); 183 int auth2_method_allowed(Authctxt *, const char *, const char *); 184 185 void privsep_challenge_enable(void); 186 187 int auth2_challenge(Authctxt *, char *); 188 void auth2_challenge_stop(Authctxt *); 189 int bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **); 190 int bsdauth_respond(void *, u_int, char **); 191 192 int allowed_user(struct passwd *); 193 struct passwd * getpwnamallow(const char *user); 194 195 char *get_challenge(Authctxt *); 196 int verify_response(Authctxt *, const char *); 197 198 char *expand_authorized_keys(const char *, struct passwd *pw); 199 char *authorized_principals_file(struct passwd *); 200 201 FILE *auth_openkeyfile(const char *, struct passwd *, int); 202 FILE *auth_openprincipals(const char *, struct passwd *, int); 203 int auth_key_is_revoked(Key *); 204 205 HostStatus 206 check_key_in_hostfiles(struct passwd *, Key *, const char *, 207 const char *, const char *); 208 209 /* hostkey handling */ 210 Key *get_hostkey_by_index(int); 211 Key *get_hostkey_public_by_index(int, struct ssh *); 212 Key *get_hostkey_public_by_type(int, int, struct ssh *); 213 Key *get_hostkey_private_by_type(int, int, struct ssh *); 214 int get_hostkey_index(Key *, int, struct ssh *); 215 int ssh1_session_key(BIGNUM *); 216 int sshd_hostkey_sign(Key *, Key *, u_char **, size_t *, 217 const u_char *, size_t, const char *, u_int); 218 219 /* debug messages during authentication */ 220 void auth_debug_add(const char *fmt,...) __attribute__((format(printf, 1, 2))); 221 void auth_debug_send(void); 222 void auth_debug_reset(void); 223 224 struct passwd *fakepw(void); 225 226 #define AUTH_FAIL_MSG "Too many authentication failures for %.100s" 227 228 #define SKEY_PROMPT "\nS/Key Password: " 229 230 #if defined(KRB5) && !defined(HEIMDAL) 231 #include <krb5.h> 232 krb5_error_code ssh_krb5_cc_gen(krb5_context, krb5_ccache *); 233 #endif 234 #endif 235