1 /* $OpenBSD: auth.h,v 1.69 2011/05/23 03:30:07 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 #include <bsd_auth.h> 36 #ifdef KRB5 37 #include <krb5.h> 38 #endif 39 40 typedef struct Authctxt Authctxt; 41 typedef struct Authmethod Authmethod; 42 typedef struct KbdintDevice KbdintDevice; 43 44 struct Authctxt { 45 sig_atomic_t success; 46 int authenticated; /* authenticated and alarms cancelled */ 47 int postponed; /* authentication needs another step */ 48 int valid; /* user exists and is allowed to login */ 49 int attempt; 50 int failures; 51 int server_caused_failure; 52 int force_pwchange; 53 char *user; /* username sent by the client */ 54 char *service; 55 struct passwd *pw; /* set if 'valid' */ 56 char *style; 57 void *kbdintctxt; 58 void *jpake_ctx; 59 auth_session_t *as; 60 #ifdef KRB5 61 krb5_context krb5_ctx; 62 krb5_ccache krb5_fwd_ccache; 63 krb5_principal krb5_user; 64 char *krb5_ticket_file; 65 #endif 66 void *methoddata; 67 }; 68 /* 69 * Every authentication method has to handle authentication requests for 70 * non-existing users, or for users that are not allowed to login. In this 71 * case 'valid' is set to 0, but 'user' points to the username requested by 72 * the client. 73 */ 74 75 struct Authmethod { 76 char *name; 77 int (*userauth)(Authctxt *authctxt); 78 int *enabled; 79 }; 80 81 /* 82 * Keyboard interactive device: 83 * init_ctx returns: non NULL upon success 84 * query returns: 0 - success, otherwise failure 85 * respond returns: 0 - success, 1 - need further interaction, 86 * otherwise - failure 87 */ 88 struct KbdintDevice 89 { 90 const char *name; 91 void* (*init_ctx)(Authctxt*); 92 int (*query)(void *ctx, char **name, char **infotxt, 93 u_int *numprompts, char ***prompts, u_int **echo_on); 94 int (*respond)(void *ctx, u_int numresp, char **responses); 95 void (*free_ctx)(void *ctx); 96 }; 97 98 int auth_rhosts(struct passwd *, const char *); 99 int 100 auth_rhosts2(struct passwd *, const char *, const char *, const char *); 101 102 int auth_rhosts_rsa(Authctxt *, char *, Key *); 103 int auth_password(Authctxt *, const char *); 104 int auth_rsa(Authctxt *, BIGNUM *); 105 int auth_rsa_challenge_dialog(Key *); 106 BIGNUM *auth_rsa_generate_challenge(Key *); 107 int auth_rsa_verify_response(Key *, BIGNUM *, u_char[]); 108 int auth_rsa_key_allowed(struct passwd *, BIGNUM *, Key **); 109 110 int auth_rhosts_rsa_key_allowed(struct passwd *, char *, char *, Key *); 111 int hostbased_key_allowed(struct passwd *, const char *, char *, Key *); 112 int user_key_allowed(struct passwd *, Key *); 113 114 #ifdef KRB5 115 int auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *); 116 int auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt); 117 int auth_krb5_password(Authctxt *authctxt, const char *password); 118 void krb5_cleanup_proc(Authctxt *authctxt); 119 #endif /* KRB5 */ 120 121 void do_authentication(Authctxt *); 122 void do_authentication2(Authctxt *); 123 124 void auth_log(Authctxt *, int, char *, char *); 125 void userauth_finish(Authctxt *, int, char *); 126 int auth_root_allowed(char *); 127 128 char *auth2_read_banner(void); 129 130 void privsep_challenge_enable(void); 131 132 int auth2_challenge(Authctxt *, char *); 133 void auth2_challenge_stop(Authctxt *); 134 int bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **); 135 int bsdauth_respond(void *, u_int, char **); 136 int skey_query(void *, char **, char **, u_int *, char ***, u_int **); 137 int skey_respond(void *, u_int, char **); 138 139 void auth2_jpake_get_pwdata(Authctxt *, BIGNUM **, char **, char **); 140 void auth2_jpake_stop(Authctxt *); 141 142 int allowed_user(struct passwd *); 143 struct passwd * getpwnamallow(const char *user); 144 145 char *get_challenge(Authctxt *); 146 int verify_response(Authctxt *, const char *); 147 148 char *expand_authorized_keys(const char *, struct passwd *pw); 149 char *authorized_principals_file(struct passwd *); 150 151 FILE *auth_openkeyfile(const char *, struct passwd *, int); 152 FILE *auth_openprincipals(const char *, struct passwd *, int); 153 int auth_key_is_revoked(Key *); 154 155 HostStatus 156 check_key_in_hostfiles(struct passwd *, Key *, const char *, 157 const char *, const char *); 158 159 /* hostkey handling */ 160 Key *get_hostkey_by_index(int); 161 Key *get_hostkey_public_by_type(int); 162 Key *get_hostkey_private_by_type(int); 163 int get_hostkey_index(Key *); 164 int ssh1_session_key(BIGNUM *); 165 166 /* debug messages during authentication */ 167 void auth_debug_add(const char *fmt,...) __attribute__((format(printf, 1, 2))); 168 void auth_debug_send(void); 169 void auth_debug_reset(void); 170 171 struct passwd *fakepw(void); 172 173 #define AUTH_FAIL_MSG "Too many authentication failures for %.100s" 174 175 #endif 176