/* $NetBSD: auth.h,v 1.19.2.1 2023/12/25 12:31:02 martin Exp $ */ /* $OpenBSD: auth.h,v 1.106 2022/06/15 16:08:25 djm Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * */ #ifndef AUTH_H #define AUTH_H #include #include #include #ifdef HAVE_LOGIN_CAP #include #endif #ifdef BSD_AUTH #include #endif #ifdef KRB5 #include #endif struct passwd; struct ssh; struct sshbuf; struct sshkey; struct sshkey_cert; struct sshauthopt; typedef struct Authctxt Authctxt; typedef struct Authmethod Authmethod; typedef struct KbdintDevice KbdintDevice; struct Authctxt { sig_atomic_t success; int authenticated; /* authenticated and alarms cancelled */ int postponed; /* authentication needs another step */ int valid; /* user exists and is allowed to login */ int attempt; int failures; int server_caused_failure; int force_pwchange; char *user; /* username sent by the client */ char *service; struct passwd *pw; /* set if 'valid' */ char *style; /* Method lists for multiple authentication */ char **auth_methods; /* modified from server config */ u_int num_auth_methods; /* Authentication method-specific data */ void *methoddata; void *kbdintctxt; #ifdef BSD_AUTH auth_session_t *as; #endif #ifdef KRB5 krb5_context krb5_ctx; krb5_auth_context krb5_auth_ctx; krb5_ccache krb5_fwd_ccache; krb5_principal krb5_user; char *krb5_ticket_file; #endif /* Authentication keys already used; these will be refused henceforth */ struct sshkey **prev_keys; u_int nprev_keys; /* Last used key and ancillary information from active auth method */ struct sshkey *auth_method_key; char *auth_method_info; /* Information exposed to session */ struct sshbuf *session_info; /* Auth info for environment */ }; /* * Every authentication method has to handle authentication requests for * non-existing users, or for users that are not allowed to login. In this * case 'valid' is set to 0, but 'user' points to the username requested by * the client. */ #ifdef USE_PAM #include "auth-pam.h" #endif struct Authmethod { const char *name; const char *synonym; int (*userauth)(struct ssh *, const char *); int *enabled; }; /* * Keyboard interactive device: * init_ctx returns: non NULL upon success * query returns: 0 - success, otherwise failure * respond returns: 0 - success, 1 - need further interaction, * otherwise - failure */ struct KbdintDevice { const char *name; void* (*init_ctx)(Authctxt*); int (*query)(void *ctx, char **name, char **infotxt, u_int *numprompts, char ***prompts, u_int **echo_on); int (*respond)(void *ctx, u_int numresp, char **responses); void (*free_ctx)(void *ctx); }; int auth_rhosts2(struct passwd *, const char *, const char *, const char *); int auth_password(struct ssh *, const char *); int hostbased_key_allowed(struct ssh *, struct passwd *, const char *, char *, struct sshkey *); int user_key_allowed(struct ssh *ssh, struct passwd *, struct sshkey *, int, struct sshauthopt **); int auth2_key_already_used(Authctxt *, const struct sshkey *); /* * Handling auth method-specific information for logging and prevention * of key reuse during multiple authentication. */ void auth2_authctxt_reset_info(Authctxt *); void auth2_record_key(Authctxt *, int, const struct sshkey *); void auth2_record_info(Authctxt *authctxt, const char *, ...) __attribute__((__format__ (printf, 2, 3))) __attribute__((__nonnull__ (2))); void auth2_update_session_info(Authctxt *, const char *, const char *); #ifdef KRB5 int auth_krb5(struct ssh *, krb5_data *auth, char **client, krb5_data *); int auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt); int auth_krb5_password(Authctxt *authctxt, const char *password); void krb5_cleanup_proc(Authctxt *authctxt); #endif /* KRB5 */ void do_authentication2(struct ssh *); void auth_log(struct ssh *, int, int, const char *, const char *); void auth_maxtries_exceeded(struct ssh *) __attribute__((noreturn)); void userauth_finish(struct ssh *, int, const char *, const char *); int auth_root_allowed(struct ssh *, const char *); char *auth2_read_banner(void); int auth2_methods_valid(const char *, int); int auth2_update_methods_lists(Authctxt *, const char *, const char *); int auth2_setup_methods_lists(Authctxt *); int auth2_method_allowed(Authctxt *, const char *, const char *); void privsep_challenge_enable(void); int auth2_challenge(struct ssh *, char *); void auth2_challenge_stop(struct ssh *); int bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **); int bsdauth_respond(void *, u_int, char **); int allowed_user(struct ssh *, struct passwd *); struct passwd * getpwnamallow(struct ssh *, const char *user); char *expand_authorized_keys(const char *, struct passwd *pw); char *authorized_principals_file(struct passwd *); int auth_key_is_revoked(struct sshkey *); const char *auth_get_canonical_hostname(struct ssh *, int); HostStatus check_key_in_hostfiles(struct passwd *, struct sshkey *, const char *, const char *, const char *); /* hostkey handling */ struct sshkey *get_hostkey_by_index(int); struct sshkey *get_hostkey_public_by_index(int, struct ssh *); struct sshkey *get_hostkey_public_by_type(int, int, struct ssh *); struct sshkey *get_hostkey_private_by_type(int, int, struct ssh *); int get_hostkey_index(struct sshkey *, int, struct ssh *); int sshd_hostkey_sign(struct ssh *, struct sshkey *, struct sshkey *, u_char **, size_t *, const u_char *, size_t, const char *); /* Key / cert options linkage to auth layer */ const struct sshauthopt *auth_options(struct ssh *); int auth_activate_options(struct ssh *, struct sshauthopt *); void auth_restrict_session(struct ssh *); void auth_log_authopts(const char *, const struct sshauthopt *, int); /* debug messages during authentication */ void auth_debug_add(const char *fmt,...) __attribute__((format(printf, 1, 2))); void auth_debug_send(struct ssh *); void auth_debug_reset(void); void disable_forwarding(void); struct passwd *fakepw(void); /* auth2-pubkeyfile.c */ int auth_authorise_keyopts(struct passwd *, struct sshauthopt *, int, const char *, const char *, const char *); int auth_check_principals_line(char *, const struct sshkey_cert *, const char *, struct sshauthopt **); int auth_process_principals(FILE *, const char *, const struct sshkey_cert *, struct sshauthopt **); int auth_check_authkey_line(struct passwd *, struct sshkey *, char *, const char *, const char *, const char *, struct sshauthopt **); int auth_check_authkeys_file(struct passwd *, FILE *, char *, struct sshkey *, const char *, const char *, struct sshauthopt **); FILE *auth_openkeyfile(const char *, struct passwd *, int); FILE *auth_openprincipals(const char *, struct passwd *, int); #endif