1 /* $OpenBSD: auth.h,v 1.49 2004/01/30 09:48:57 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 "key.h" 32 #include "hostfile.h" 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 int success; 51 int postponed; /* authentication needs another step */ 52 int valid; /* user exists and is allowed to login */ 53 int attempt; 54 int failures; 55 int force_pwchange; 56 char *user; /* username sent by the client */ 57 char *service; 58 struct passwd *pw; /* set if 'valid' */ 59 char *style; 60 void *kbdintctxt; 61 #ifdef BSD_AUTH 62 auth_session_t *as; 63 #endif 64 #ifdef KRB5 65 krb5_context krb5_ctx; 66 krb5_ccache krb5_fwd_ccache; 67 krb5_principal krb5_user; 68 char *krb5_ticket_file; 69 #endif 70 void *methoddata; 71 }; 72 /* 73 * Every authentication method has to handle authentication requests for 74 * non-existing users, or for users that are not allowed to login. In this 75 * case 'valid' is set to 0, but 'user' points to the username requested by 76 * the client. 77 */ 78 79 struct Authmethod { 80 char *name; 81 int (*userauth)(Authctxt *authctxt); 82 int *enabled; 83 }; 84 85 /* 86 * Keyboard interactive device: 87 * init_ctx returns: non NULL upon success 88 * query returns: 0 - success, otherwise failure 89 * respond returns: 0 - success, 1 - need further interaction, 90 * otherwise - failure 91 */ 92 struct KbdintDevice 93 { 94 const char *name; 95 void* (*init_ctx)(Authctxt*); 96 int (*query)(void *ctx, char **name, char **infotxt, 97 u_int *numprompts, char ***prompts, u_int **echo_on); 98 int (*respond)(void *ctx, u_int numresp, char **responses); 99 void (*free_ctx)(void *ctx); 100 }; 101 102 int auth_rhosts(struct passwd *, const char *); 103 int 104 auth_rhosts2(struct passwd *, const char *, const char *, const char *); 105 106 int auth_rhosts_rsa(Authctxt *, char *, Key *); 107 int auth_password(Authctxt *, const char *); 108 int auth_rsa(Authctxt *, BIGNUM *); 109 int auth_rsa_challenge_dialog(Key *); 110 BIGNUM *auth_rsa_generate_challenge(Key *); 111 int auth_rsa_verify_response(Key *, BIGNUM *, u_char[]); 112 int auth_rsa_key_allowed(struct passwd *, BIGNUM *, Key **); 113 114 int auth_rhosts_rsa_key_allowed(struct passwd *, char *, char *, Key *); 115 int hostbased_key_allowed(struct passwd *, const char *, char *, Key *); 116 int user_key_allowed(struct passwd *, Key *); 117 118 #ifdef KRB5 119 int auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *); 120 int auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt); 121 int auth_krb5_password(Authctxt *authctxt, const char *password); 122 void krb5_cleanup_proc(Authctxt *authctxt); 123 #endif /* KRB5 */ 124 125 void do_authentication(Authctxt *); 126 void do_authentication2(Authctxt *); 127 128 void auth_log(Authctxt *, int, char *, char *); 129 void userauth_finish(Authctxt *, int, char *); 130 int auth_root_allowed(char *); 131 132 char *auth2_read_banner(void); 133 134 void privsep_challenge_enable(void); 135 136 int auth2_challenge(Authctxt *, char *); 137 void auth2_challenge_stop(Authctxt *); 138 int bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **); 139 int bsdauth_respond(void *, u_int, char **); 140 int skey_query(void *, char **, char **, u_int *, char ***, u_int **); 141 int skey_respond(void *, u_int, char **); 142 143 int allowed_user(struct passwd *); 144 struct passwd * getpwnamallow(const char *user); 145 146 char *get_challenge(Authctxt *); 147 int verify_response(Authctxt *, const char *); 148 149 char *expand_filename(const char *, struct passwd *); 150 char *authorized_keys_file(struct passwd *); 151 char *authorized_keys_file2(struct passwd *); 152 153 int 154 secure_filename(FILE *, const char *, struct passwd *, char *, size_t); 155 156 HostStatus 157 check_key_in_hostfiles(struct passwd *, Key *, const char *, 158 const char *, const char *); 159 160 /* hostkey handling */ 161 Key *get_hostkey_by_index(int); 162 Key *get_hostkey_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_MAX 6 174 #define AUTH_FAIL_LOG (AUTH_FAIL_MAX/2) 175 #define AUTH_FAIL_MSG "Too many authentication failures for %.100s" 176 177 #define SKEY_PROMPT "\nS/Key Password: " 178 #endif 179