1 /* $NetBSD: auth.h,v 1.26 2026/04/08 18:58:40 christos Exp $ */ 2 /* $OpenBSD: auth.h,v 1.109 2026/02/06 01:24:36 djm 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 #include <stdio.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 passwd; 46 struct ssh; 47 struct sshbuf; 48 struct sshkey; 49 struct sshkey_cert; 50 struct sshauthopt; 51 52 typedef struct Authctxt Authctxt; 53 typedef struct Authmethod Authmethod; 54 typedef struct KbdintDevice KbdintDevice; 55 56 struct Authctxt { 57 sig_atomic_t success; 58 int authenticated; /* authenticated and alarms cancelled */ 59 int postponed; /* authentication needs another step */ 60 int valid; /* user exists and is allowed to login */ 61 int attempt; 62 int failures; 63 int server_caused_failure; 64 int force_pwchange; 65 char *user; /* username sent by the client */ 66 char *service; 67 struct passwd *pw; /* set if 'valid' */ 68 char *style; 69 70 /* Method lists for multiple authentication */ 71 char **auth_methods; /* modified from server config */ 72 u_int num_auth_methods; 73 74 /* Authentication method-specific data */ 75 void *methoddata; 76 void *kbdintctxt; 77 #ifdef BSD_AUTH 78 auth_session_t *as; 79 #endif 80 #ifdef KRB5 81 krb5_context krb5_ctx; 82 krb5_auth_context krb5_auth_ctx; 83 krb5_ccache krb5_fwd_ccache; 84 krb5_principal krb5_user; 85 char *krb5_ticket_file; 86 #endif 87 88 /* Authentication keys already used; these will be refused henceforth */ 89 struct sshkey **prev_keys; 90 u_int nprev_keys; 91 92 /* Last used key and ancillary information from active auth method */ 93 struct sshkey *auth_method_key; 94 char *auth_method_info; 95 96 /* Information exposed to session */ 97 struct sshbuf *session_info; /* Auth info for environment */ 98 }; 99 100 /* 101 * Every authentication method has to handle authentication requests for 102 * non-existing users, or for users that are not allowed to login. In this 103 * case 'valid' is set to 0, but 'user' points to the username requested by 104 * the client. 105 */ 106 107 #ifdef USE_PAM 108 #include "auth-pam.h" 109 #endif 110 111 struct authmethod_cfg { 112 const char *name; 113 const char *synonym; 114 int *enabled; 115 }; 116 117 struct Authmethod { 118 struct authmethod_cfg *cfg; 119 int (*userauth)(struct ssh *, const char *); 120 }; 121 122 /* 123 * Keyboard interactive device: 124 * init_ctx returns: non NULL upon success 125 * query returns: 0 - success, otherwise failure 126 * respond returns: 0 - success, 1 - need further interaction, 127 * otherwise - failure 128 */ 129 struct KbdintDevice 130 { 131 const char *name; 132 void* (*init_ctx)(Authctxt*); 133 int (*query)(void *ctx, char **name, char **infotxt, 134 u_int *numprompts, char ***prompts, u_int **echo_on); 135 int (*respond)(void *ctx, u_int numresp, char **responses); 136 void (*free_ctx)(void *ctx); 137 }; 138 139 int 140 auth_rhosts2(struct passwd *, const char *, const char *, const char *); 141 142 int auth_password(struct ssh *, const char *); 143 144 int hostbased_key_allowed(struct ssh *, struct passwd *, 145 const char *, char *, struct sshkey *); 146 int user_key_allowed(struct ssh *ssh, struct passwd *, struct sshkey *, 147 int, struct sshauthopt **); 148 int auth2_key_already_used(Authctxt *, const struct sshkey *); 149 150 /* 151 * Handling auth method-specific information for logging and prevention 152 * of key reuse during multiple authentication. 153 */ 154 void auth2_authctxt_reset_info(Authctxt *); 155 void auth2_record_key(Authctxt *, int, const struct sshkey *); 156 void auth2_record_info(Authctxt *authctxt, const char *, ...) 157 __attribute__((__format__ (printf, 2, 3))) 158 __attribute__((__nonnull__ (2))); 159 void auth2_update_session_info(Authctxt *, const char *, const char *); 160 161 #ifdef KRB5 162 int auth_krb5(struct ssh *, 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_authentication2(struct ssh *); 169 170 void auth_log(struct ssh *, int, int, const char *, const char *); 171 void auth_maxtries_exceeded(struct ssh *) __attribute__((noreturn)); 172 void userauth_finish(struct ssh *, int, const char *, const char *); 173 int auth_root_allowed(struct ssh *, const char *); 174 175 char *auth2_read_banner(void); 176 int auth2_methods_valid(const char *, int); 177 int auth2_update_methods_lists(Authctxt *, const char *, const char *); 178 int auth2_setup_methods_lists(Authctxt *); 179 int auth2_method_allowed(Authctxt *, const char *, const char *); 180 181 int auth2_challenge(struct ssh *, char *); 182 void auth2_challenge_stop(struct ssh *); 183 int bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **); 184 int bsdauth_respond(void *, u_int, char **); 185 186 int allowed_user(struct ssh *, struct passwd *); 187 struct passwd * getpwnamallow(struct ssh *, const char *user); 188 189 char *expand_authorized_keys(const char *, struct passwd *pw); 190 char *authorized_principals_file(struct passwd *); 191 192 int auth_key_is_revoked(struct sshkey *); 193 194 const char *auth_get_canonical_hostname(struct ssh *, int); 195 196 HostStatus 197 check_key_in_hostfiles(struct passwd *, struct sshkey *, const char *, 198 const char *, const char *); 199 200 /* hostkey handling */ 201 struct sshkey *get_hostkey_by_index(int); 202 struct sshkey *get_hostkey_public_by_index(int, struct ssh *); 203 struct sshkey *get_hostkey_public_by_type(int, int, struct ssh *); 204 struct sshkey *get_hostkey_private_by_type(int, int, struct ssh *); 205 int get_hostkey_index(struct sshkey *, int, struct ssh *); 206 int sshd_hostkey_sign(struct ssh *, struct sshkey *, struct sshkey *, 207 u_char **, size_t *, const u_char *, size_t, const char *); 208 209 /* Key / cert options linkage to auth layer */ 210 int auth_activate_options(struct ssh *, struct sshauthopt *); 211 void auth_restrict_session(struct ssh *); 212 void auth_log_authopts(const char *, const struct sshauthopt *, int); 213 214 /* debug messages during authentication */ 215 void auth_debug_add(const char *fmt,...) 216 __attribute__((format(printf, 1, 2))); 217 void auth_debug_send(struct ssh *); 218 void auth_debug_reset(void); 219 220 void disable_forwarding(void); 221 222 struct passwd *fakepw(void); 223 224 /* auth2-pubkeyfile.c */ 225 int auth_authorise_keyopts(struct passwd *, struct sshauthopt *, int, 226 const char *, const char *, const char *); 227 int auth_check_principals_line(char *, const struct sshkey_cert *, 228 const char *, struct sshauthopt **); 229 int auth_process_principals(FILE *, const char *, 230 const struct sshkey_cert *, struct sshauthopt **); 231 int auth_check_authkey_line(struct passwd *, struct sshkey *, 232 char *, const char *, const char *, const char *, struct sshauthopt **); 233 int auth_check_authkeys_file(struct passwd *, FILE *, char *, 234 struct sshkey *, const char *, const char *, struct sshauthopt **); 235 FILE *auth_openkeyfile(const char *, struct passwd *, int); 236 FILE *auth_openprincipals(const char *, struct passwd *, int); 237 238 #endif 239
Indexes created Wed Jul 29 00:25:28 UTC 2026