1 /* $OpenBSD: auth.h,v 1.88 2016/05/04 14:04:40 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 <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 struct ssh; 46 struct sshkey; 47 48 typedef struct Authctxt Authctxt; 49 typedef struct Authmethod Authmethod; 50 typedef struct KbdintDevice KbdintDevice; 51 52 struct Authctxt { 53 sig_atomic_t success; 54 int authenticated; /* authenticated and alarms cancelled */ 55 int postponed; /* authentication needs another step */ 56 int valid; /* user exists and is allowed to login */ 57 int attempt; 58 int failures; 59 int server_caused_failure; 60 int force_pwchange; 61 char *user; /* username sent by the client */ 62 char *service; 63 struct passwd *pw; /* set if 'valid' */ 64 char *style; 65 void *kbdintctxt; 66 char *info; /* Extra info for next auth_log */ 67 #ifdef BSD_AUTH 68 auth_session_t *as; 69 #endif 70 char **auth_methods; /* modified from server config */ 71 u_int num_auth_methods; 72 #ifdef KRB5 73 krb5_context krb5_ctx; 74 krb5_ccache krb5_fwd_ccache; 75 krb5_principal krb5_user; 76 char *krb5_ticket_file; 77 char *krb5_ccname; 78 #endif 79 Buffer *loginmsg; 80 void *methoddata; 81 82 struct sshkey **prev_userkeys; 83 u_int nprev_userkeys; 84 }; 85 /* 86 * Every authentication method has to handle authentication requests for 87 * non-existing users, or for users that are not allowed to login. In this 88 * case 'valid' is set to 0, but 'user' points to the username requested by 89 * the client. 90 */ 91 92 struct Authmethod { 93 char *name; 94 int (*userauth)(Authctxt *authctxt); 95 int *enabled; 96 }; 97 98 /* 99 * Keyboard interactive device: 100 * init_ctx returns: non NULL upon success 101 * query returns: 0 - success, otherwise failure 102 * respond returns: 0 - success, 1 - need further interaction, 103 * otherwise - failure 104 */ 105 struct KbdintDevice 106 { 107 const char *name; 108 void* (*init_ctx)(Authctxt*); 109 int (*query)(void *ctx, char **name, char **infotxt, 110 u_int *numprompts, char ***prompts, u_int **echo_on); 111 int (*respond)(void *ctx, u_int numresp, char **responses); 112 void (*free_ctx)(void *ctx); 113 }; 114 115 int auth_rhosts(struct passwd *, const char *); 116 int 117 auth_rhosts2(struct passwd *, const char *, const char *, const char *); 118 119 int auth_rhosts_rsa(Authctxt *, char *, Key *); 120 int auth_password(Authctxt *, const char *); 121 int auth_rsa(Authctxt *, BIGNUM *); 122 int auth_rsa_challenge_dialog(Key *); 123 BIGNUM *auth_rsa_generate_challenge(Key *); 124 int auth_rsa_verify_response(Key *, BIGNUM *, u_char[]); 125 int auth_rsa_key_allowed(struct passwd *, BIGNUM *, Key **); 126 127 int auth_rhosts_rsa_key_allowed(struct passwd *, const char *, 128 const char *, Key *); 129 int hostbased_key_allowed(struct passwd *, const char *, char *, Key *); 130 int user_key_allowed(struct passwd *, Key *, int); 131 void pubkey_auth_info(Authctxt *, const Key *, const char *, ...) 132 __attribute__((__format__ (printf, 3, 4))); 133 void auth2_record_userkey(Authctxt *, struct sshkey *); 134 int auth2_userkey_already_used(Authctxt *, struct sshkey *); 135 136 struct stat; 137 int auth_secure_path(const char *, struct stat *, const char *, uid_t, 138 char *, size_t); 139 140 #ifdef KRB5 141 int auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *); 142 int auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt); 143 int auth_krb5_password(Authctxt *authctxt, const char *password); 144 void krb5_cleanup_proc(Authctxt *authctxt); 145 #endif /* KRB5 */ 146 147 #if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE) 148 #include <shadow.h> 149 int auth_shadow_acctexpired(struct spwd *); 150 int auth_shadow_pwexpired(Authctxt *); 151 #endif 152 153 #include "auth-pam.h" 154 #include "audit.h" 155 void remove_kbdint_device(const char *); 156 157 void disable_forwarding(void); 158 159 void do_authentication(Authctxt *); 160 void do_authentication2(Authctxt *); 161 162 void auth_info(Authctxt *authctxt, const char *, ...) 163 __attribute__((__format__ (printf, 2, 3))) 164 __attribute__((__nonnull__ (2))); 165 void auth_log(Authctxt *, int, int, const char *, const char *); 166 void auth_maxtries_exceeded(Authctxt *) __attribute__((noreturn)); 167 void userauth_finish(Authctxt *, int, const char *, const char *); 168 int auth_root_allowed(const char *); 169 170 void userauth_send_banner(const char *); 171 172 char *auth2_read_banner(void); 173 int auth2_methods_valid(const char *, int); 174 int auth2_update_methods_lists(Authctxt *, const char *, const char *); 175 int auth2_setup_methods_lists(Authctxt *); 176 int auth2_method_allowed(Authctxt *, const char *, const char *); 177 178 void privsep_challenge_enable(void); 179 180 int auth2_challenge(Authctxt *, char *); 181 void auth2_challenge_stop(Authctxt *); 182 int bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **); 183 int bsdauth_respond(void *, u_int, char **); 184 int skey_query(void *, char **, char **, u_int *, char ***, u_int **); 185 int skey_respond(void *, u_int, char **); 186 187 int allowed_user(struct passwd *); 188 struct passwd * getpwnamallow(const char *user); 189 190 char *get_challenge(Authctxt *); 191 int verify_response(Authctxt *, const char *); 192 void abandon_challenge_response(Authctxt *); 193 194 char *expand_authorized_keys(const char *, struct passwd *pw); 195 char *authorized_principals_file(struct passwd *); 196 197 FILE *auth_openkeyfile(const char *, struct passwd *, int); 198 FILE *auth_openprincipals(const char *, struct passwd *, int); 199 int auth_key_is_revoked(Key *); 200 201 const char *auth_get_canonical_hostname(struct ssh *, int); 202 203 HostStatus 204 check_key_in_hostfiles(struct passwd *, Key *, const char *, 205 const char *, const char *); 206 207 /* hostkey handling */ 208 Key *get_hostkey_by_index(int); 209 Key *get_hostkey_public_by_index(int, struct ssh *); 210 Key *get_hostkey_public_by_type(int, int, struct ssh *); 211 Key *get_hostkey_private_by_type(int, int, struct ssh *); 212 int get_hostkey_index(Key *, int, struct ssh *); 213 int ssh1_session_key(BIGNUM *); 214 int sshd_hostkey_sign(Key *, Key *, u_char **, size_t *, 215 const u_char *, size_t, const char *, u_int); 216 217 /* debug messages during authentication */ 218 void auth_debug_add(const char *fmt,...) __attribute__((format(printf, 1, 2))); 219 void auth_debug_send(void); 220 void auth_debug_reset(void); 221 222 struct passwd *fakepw(void); 223 224 int sys_auth_passwd(Authctxt *, const char *); 225 226 #define SKEY_PROMPT "\nS/Key Password: " 227 228 #if defined(KRB5) && !defined(HEIMDAL) 229 #include <krb5.h> 230 krb5_error_code ssh_krb5_cc_gen(krb5_context, krb5_ccache *); 231 #endif 232 #endif 233