138a52bd3SEd Maste /* $OpenBSD: auth.h,v 1.106 2022/06/15 16:08:25 djm Exp $ */ 2af12a3e7SDag-Erling Smørgrav 3b66f2d16SKris Kennaway /* 4b66f2d16SKris Kennaway * Copyright (c) 2000 Markus Friedl. All rights reserved. 5b66f2d16SKris Kennaway * 6b66f2d16SKris Kennaway * Redistribution and use in source and binary forms, with or without 7b66f2d16SKris Kennaway * modification, are permitted provided that the following conditions 8b66f2d16SKris Kennaway * are met: 9b66f2d16SKris Kennaway * 1. Redistributions of source code must retain the above copyright 10b66f2d16SKris Kennaway * notice, this list of conditions and the following disclaimer. 11b66f2d16SKris Kennaway * 2. Redistributions in binary form must reproduce the above copyright 12b66f2d16SKris Kennaway * notice, this list of conditions and the following disclaimer in the 13b66f2d16SKris Kennaway * documentation and/or other materials provided with the distribution. 14b66f2d16SKris Kennaway * 15b66f2d16SKris Kennaway * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16b66f2d16SKris Kennaway * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17b66f2d16SKris Kennaway * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18b66f2d16SKris Kennaway * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19b66f2d16SKris Kennaway * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20b66f2d16SKris Kennaway * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21b66f2d16SKris Kennaway * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22b66f2d16SKris Kennaway * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23b66f2d16SKris Kennaway * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24b66f2d16SKris Kennaway * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 255b9b2fafSBrian Feldman * 26b66f2d16SKris Kennaway */ 27af12a3e7SDag-Erling Smørgrav 28a04a10f8SKris Kennaway #ifndef AUTH_H 29a04a10f8SKris Kennaway #define AUTH_H 30a04a10f8SKris Kennaway 31333ee039SDag-Erling Smørgrav #include <signal.h> 3238a52bd3SEd Maste #include <stdio.h> 33333ee039SDag-Erling Smørgrav 341e8db6e2SBrian Feldman #ifdef HAVE_LOGIN_CAP 351e8db6e2SBrian Feldman #include <login_cap.h> 361e8db6e2SBrian Feldman #endif 371e8db6e2SBrian Feldman #ifdef BSD_AUTH 381e8db6e2SBrian Feldman #include <bsd_auth.h> 391e8db6e2SBrian Feldman #endif 40af12a3e7SDag-Erling Smørgrav #ifdef KRB5 41af12a3e7SDag-Erling Smørgrav #include <krb5.h> 42af12a3e7SDag-Erling Smørgrav #endif 431e8db6e2SBrian Feldman 4447dd1d1bSDag-Erling Smørgrav struct passwd; 45bc5531deSDag-Erling Smørgrav struct ssh; 464f52dfbbSDag-Erling Smørgrav struct sshbuf; 4747dd1d1bSDag-Erling Smørgrav struct sshkey; 4838a52bd3SEd Maste struct sshkey_cert; 4947dd1d1bSDag-Erling Smørgrav struct sshauthopt; 50bc5531deSDag-Erling Smørgrav 515b9b2fafSBrian Feldman typedef struct Authctxt Authctxt; 5280628bacSDag-Erling Smørgrav typedef struct Authmethod Authmethod; 53af12a3e7SDag-Erling Smørgrav typedef struct KbdintDevice KbdintDevice; 54af12a3e7SDag-Erling Smørgrav 555b9b2fafSBrian Feldman struct Authctxt { 56333ee039SDag-Erling Smørgrav sig_atomic_t success; 57333ee039SDag-Erling Smørgrav int authenticated; /* authenticated and alarms cancelled */ 58cf2b5f3bSDag-Erling Smørgrav int postponed; /* authentication needs another step */ 59cf2b5f3bSDag-Erling Smørgrav int valid; /* user exists and is allowed to login */ 605b9b2fafSBrian Feldman int attempt; 611e8db6e2SBrian Feldman int failures; 62e146993eSDag-Erling Smørgrav int server_caused_failure; 631ec0d754SDag-Erling Smørgrav int force_pwchange; 64cf2b5f3bSDag-Erling Smørgrav char *user; /* username sent by the client */ 655b9b2fafSBrian Feldman char *service; 66cf2b5f3bSDag-Erling Smørgrav struct passwd *pw; /* set if 'valid' */ 671e8db6e2SBrian Feldman char *style; 684f52dfbbSDag-Erling Smørgrav 694f52dfbbSDag-Erling Smørgrav /* Method lists for multiple authentication */ 704f52dfbbSDag-Erling Smørgrav char **auth_methods; /* modified from server config */ 714f52dfbbSDag-Erling Smørgrav u_int num_auth_methods; 724f52dfbbSDag-Erling Smørgrav 734f52dfbbSDag-Erling Smørgrav /* Authentication method-specific data */ 744f52dfbbSDag-Erling Smørgrav void *methoddata; 75af12a3e7SDag-Erling Smørgrav void *kbdintctxt; 761e8db6e2SBrian Feldman #ifdef BSD_AUTH 771e8db6e2SBrian Feldman auth_session_t *as; 781e8db6e2SBrian Feldman #endif 79af12a3e7SDag-Erling Smørgrav #ifdef KRB5 80af12a3e7SDag-Erling Smørgrav krb5_context krb5_ctx; 81af12a3e7SDag-Erling Smørgrav krb5_ccache krb5_fwd_ccache; 82af12a3e7SDag-Erling Smørgrav krb5_principal krb5_user; 83af12a3e7SDag-Erling Smørgrav char *krb5_ticket_file; 845962c0e9SDag-Erling Smørgrav char *krb5_ccname; 85af12a3e7SDag-Erling Smørgrav #endif 864f52dfbbSDag-Erling Smørgrav struct sshbuf *loginmsg; 87bc5531deSDag-Erling Smørgrav 884f52dfbbSDag-Erling Smørgrav /* Authentication keys already used; these will be refused henceforth */ 894f52dfbbSDag-Erling Smørgrav struct sshkey **prev_keys; 904f52dfbbSDag-Erling Smørgrav u_int nprev_keys; 914f52dfbbSDag-Erling Smørgrav 92190cef3dSDag-Erling Smørgrav /* Last used key and ancillary information from active auth method */ 934f52dfbbSDag-Erling Smørgrav struct sshkey *auth_method_key; 944f52dfbbSDag-Erling Smørgrav char *auth_method_info; 954f52dfbbSDag-Erling Smørgrav 964f52dfbbSDag-Erling Smørgrav /* Information exposed to session */ 974f52dfbbSDag-Erling Smørgrav struct sshbuf *session_info; /* Auth info for environment */ 985b9b2fafSBrian Feldman }; 994f52dfbbSDag-Erling Smørgrav 100cf2b5f3bSDag-Erling Smørgrav /* 101cf2b5f3bSDag-Erling Smørgrav * Every authentication method has to handle authentication requests for 102cf2b5f3bSDag-Erling Smørgrav * non-existing users, or for users that are not allowed to login. In this 103cf2b5f3bSDag-Erling Smørgrav * case 'valid' is set to 0, but 'user' points to the username requested by 104cf2b5f3bSDag-Erling Smørgrav * the client. 105cf2b5f3bSDag-Erling Smørgrav */ 1065b9b2fafSBrian Feldman 10780628bacSDag-Erling Smørgrav struct Authmethod { 10880628bacSDag-Erling Smørgrav char *name; 1091323ec57SEd Maste char *synonym; 1101323ec57SEd Maste int (*userauth)(struct ssh *, const char *); 11180628bacSDag-Erling Smørgrav int *enabled; 11280628bacSDag-Erling Smørgrav }; 11380628bacSDag-Erling Smørgrav 1141e8db6e2SBrian Feldman /* 115af12a3e7SDag-Erling Smørgrav * Keyboard interactive device: 116af12a3e7SDag-Erling Smørgrav * init_ctx returns: non NULL upon success 117af12a3e7SDag-Erling Smørgrav * query returns: 0 - success, otherwise failure 118af12a3e7SDag-Erling Smørgrav * respond returns: 0 - success, 1 - need further interaction, 119af12a3e7SDag-Erling Smørgrav * otherwise - failure 1201e8db6e2SBrian Feldman */ 121af12a3e7SDag-Erling Smørgrav struct KbdintDevice 122af12a3e7SDag-Erling Smørgrav { 123af12a3e7SDag-Erling Smørgrav const char *name; 124af12a3e7SDag-Erling Smørgrav void* (*init_ctx)(Authctxt*); 125af12a3e7SDag-Erling Smørgrav int (*query)(void *ctx, char **name, char **infotxt, 126af12a3e7SDag-Erling Smørgrav u_int *numprompts, char ***prompts, u_int **echo_on); 127af12a3e7SDag-Erling Smørgrav int (*respond)(void *ctx, u_int numresp, char **responses); 128af12a3e7SDag-Erling Smørgrav void (*free_ctx)(void *ctx); 129af12a3e7SDag-Erling Smørgrav }; 1301e8db6e2SBrian Feldman 1311e8db6e2SBrian Feldman int 132af12a3e7SDag-Erling Smørgrav auth_rhosts2(struct passwd *, const char *, const char *, const char *); 1331e8db6e2SBrian Feldman 13447dd1d1bSDag-Erling Smørgrav int auth_password(struct ssh *, const char *); 13580628bacSDag-Erling Smørgrav 13619261079SEd Maste int hostbased_key_allowed(struct ssh *, struct passwd *, 13719261079SEd Maste const char *, char *, struct sshkey *); 13838a52bd3SEd Maste int user_key_allowed(struct ssh *ssh, struct passwd *, struct sshkey *, 13938a52bd3SEd Maste int, struct sshauthopt **); 1404f52dfbbSDag-Erling Smørgrav int auth2_key_already_used(Authctxt *, const struct sshkey *); 1411e8db6e2SBrian Feldman 1424f52dfbbSDag-Erling Smørgrav /* 1434f52dfbbSDag-Erling Smørgrav * Handling auth method-specific information for logging and prevention 1444f52dfbbSDag-Erling Smørgrav * of key reuse during multiple authentication. 1454f52dfbbSDag-Erling Smørgrav */ 1464f52dfbbSDag-Erling Smørgrav void auth2_authctxt_reset_info(Authctxt *); 1474f52dfbbSDag-Erling Smørgrav void auth2_record_key(Authctxt *, int, const struct sshkey *); 1484f52dfbbSDag-Erling Smørgrav void auth2_record_info(Authctxt *authctxt, const char *, ...) 1494f52dfbbSDag-Erling Smørgrav __attribute__((__format__ (printf, 2, 3))) 1504f52dfbbSDag-Erling Smørgrav __attribute__((__nonnull__ (2))); 1514f52dfbbSDag-Erling Smørgrav void auth2_update_session_info(Authctxt *, const char *, const char *); 1526888a9beSDag-Erling Smørgrav 153af12a3e7SDag-Erling Smørgrav #ifdef KRB5 154f388f5efSDag-Erling Smørgrav int auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *); 155af12a3e7SDag-Erling Smørgrav int auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt); 156af12a3e7SDag-Erling Smørgrav int auth_krb5_password(Authctxt *authctxt, const char *password); 1571ec0d754SDag-Erling Smørgrav void krb5_cleanup_proc(Authctxt *authctxt); 158af12a3e7SDag-Erling Smørgrav #endif /* KRB5 */ 159af12a3e7SDag-Erling Smørgrav 1601ec0d754SDag-Erling Smørgrav #if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE) 1611ec0d754SDag-Erling Smørgrav #include <shadow.h> 1621ec0d754SDag-Erling Smørgrav int auth_shadow_acctexpired(struct spwd *); 1631ec0d754SDag-Erling Smørgrav int auth_shadow_pwexpired(Authctxt *); 1641ec0d754SDag-Erling Smørgrav #endif 1651ec0d754SDag-Erling Smørgrav 166989dd127SDag-Erling Smørgrav #include "auth-pam.h" 167aa49c926SDag-Erling Smørgrav #include "audit.h" 168aa49c926SDag-Erling Smørgrav void remove_kbdint_device(const char *); 169aa49c926SDag-Erling Smørgrav 17019261079SEd Maste void do_authentication2(struct ssh *); 171a04a10f8SKris Kennaway 17219261079SEd Maste void auth_log(struct ssh *, int, int, const char *, const char *); 17319261079SEd Maste void auth_maxtries_exceeded(struct ssh *) __attribute__((noreturn)); 1744f52dfbbSDag-Erling Smørgrav void userauth_finish(struct ssh *, int, const char *, const char *); 17547dd1d1bSDag-Erling Smørgrav int auth_root_allowed(struct ssh *, const char *); 1766888a9beSDag-Erling Smørgrav 17780628bacSDag-Erling Smørgrav char *auth2_read_banner(void); 1786888a9beSDag-Erling Smørgrav int auth2_methods_valid(const char *, int); 179e4a9863fSDag-Erling Smørgrav int auth2_update_methods_lists(Authctxt *, const char *, const char *); 1806888a9beSDag-Erling Smørgrav int auth2_setup_methods_lists(Authctxt *); 181e4a9863fSDag-Erling Smørgrav int auth2_method_allowed(Authctxt *, const char *, const char *); 18280628bacSDag-Erling Smørgrav 18380628bacSDag-Erling Smørgrav void privsep_challenge_enable(void); 18480628bacSDag-Erling Smørgrav 1854f52dfbbSDag-Erling Smørgrav int auth2_challenge(struct ssh *, char *); 1864f52dfbbSDag-Erling Smørgrav void auth2_challenge_stop(struct ssh *); 18780628bacSDag-Erling Smørgrav int bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **); 18880628bacSDag-Erling Smørgrav int bsdauth_respond(void *, u_int, char **); 189a04a10f8SKris Kennaway 19019261079SEd Maste int allowed_user(struct ssh *, struct passwd *); 19119261079SEd Maste struct passwd * getpwnamallow(struct ssh *, const char *user); 1921e8db6e2SBrian Feldman 193e146993eSDag-Erling Smørgrav char *expand_authorized_keys(const char *, struct passwd *pw); 194e2f6069cSDag-Erling Smørgrav char *authorized_principals_file(struct passwd *); 195af12a3e7SDag-Erling Smørgrav 1964f52dfbbSDag-Erling Smørgrav int auth_key_is_revoked(struct sshkey *); 197af12a3e7SDag-Erling Smørgrav 198076ad2f8SDag-Erling Smørgrav const char *auth_get_canonical_hostname(struct ssh *, int); 199076ad2f8SDag-Erling Smørgrav 200af12a3e7SDag-Erling Smørgrav HostStatus 2014f52dfbbSDag-Erling Smørgrav check_key_in_hostfiles(struct passwd *, struct sshkey *, const char *, 202af12a3e7SDag-Erling Smørgrav const char *, const char *); 203af12a3e7SDag-Erling Smørgrav 20480628bacSDag-Erling Smørgrav /* hostkey handling */ 2054f52dfbbSDag-Erling Smørgrav struct sshkey *get_hostkey_by_index(int); 2064f52dfbbSDag-Erling Smørgrav struct sshkey *get_hostkey_public_by_index(int, struct ssh *); 2074f52dfbbSDag-Erling Smørgrav struct sshkey *get_hostkey_public_by_type(int, int, struct ssh *); 2084f52dfbbSDag-Erling Smørgrav struct sshkey *get_hostkey_private_by_type(int, int, struct ssh *); 2094f52dfbbSDag-Erling Smørgrav int get_hostkey_index(struct sshkey *, int, struct ssh *); 21019261079SEd Maste int sshd_hostkey_sign(struct ssh *, struct sshkey *, struct sshkey *, 21119261079SEd Maste u_char **, size_t *, const u_char *, size_t, const char *); 21280628bacSDag-Erling Smørgrav 21347dd1d1bSDag-Erling Smørgrav /* Key / cert options linkage to auth layer */ 21447dd1d1bSDag-Erling Smørgrav const struct sshauthopt *auth_options(struct ssh *); 21547dd1d1bSDag-Erling Smørgrav int auth_activate_options(struct ssh *, struct sshauthopt *); 21647dd1d1bSDag-Erling Smørgrav void auth_restrict_session(struct ssh *); 21747dd1d1bSDag-Erling Smørgrav void auth_log_authopts(const char *, const struct sshauthopt *, int); 21847dd1d1bSDag-Erling Smørgrav 21980628bacSDag-Erling Smørgrav /* debug messages during authentication */ 22047dd1d1bSDag-Erling Smørgrav void auth_debug_add(const char *fmt,...) 22147dd1d1bSDag-Erling Smørgrav __attribute__((format(printf, 1, 2))); 22219261079SEd Maste void auth_debug_send(struct ssh *); 22380628bacSDag-Erling Smørgrav void auth_debug_reset(void); 22480628bacSDag-Erling Smørgrav 225cf2b5f3bSDag-Erling Smørgrav struct passwd *fakepw(void); 226cf2b5f3bSDag-Erling Smørgrav 22738a52bd3SEd Maste /* auth2-pubkeyfile.c */ 22838a52bd3SEd Maste int auth_authorise_keyopts(struct passwd *, struct sshauthopt *, int, 22938a52bd3SEd Maste const char *, const char *, const char *); 23038a52bd3SEd Maste int auth_check_principals_line(char *, const struct sshkey_cert *, 23138a52bd3SEd Maste const char *, struct sshauthopt **); 23238a52bd3SEd Maste int auth_process_principals(FILE *, const char *, 23338a52bd3SEd Maste const struct sshkey_cert *, struct sshauthopt **); 23438a52bd3SEd Maste int auth_check_authkey_line(struct passwd *, struct sshkey *, 23538a52bd3SEd Maste char *, const char *, const char *, const char *, struct sshauthopt **); 23638a52bd3SEd Maste int auth_check_authkeys_file(struct passwd *, FILE *, char *, 23738a52bd3SEd Maste struct sshkey *, const char *, const char *, struct sshauthopt **); 23838a52bd3SEd Maste FILE *auth_openkeyfile(const char *, struct passwd *, int); 23938a52bd3SEd Maste FILE *auth_openprincipals(const char *, struct passwd *, int); 24038a52bd3SEd Maste 24147dd1d1bSDag-Erling Smørgrav int sys_auth_passwd(struct ssh *, const char *); 242aa49c926SDag-Erling Smørgrav 243d4ecd108SDag-Erling Smørgrav #if defined(KRB5) && !defined(HEIMDAL) 244d4ecd108SDag-Erling Smørgrav krb5_error_code ssh_krb5_cc_gen(krb5_context, krb5_ccache *); 245d4ecd108SDag-Erling Smørgrav #endif 24619261079SEd Maste 24719261079SEd Maste #endif /* AUTH_H */ 248