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/* $OpenBSD: auth.h,v 1.108 2024/05/17 06:42:04 jsg 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 <signal.h>
#include <stdio.h>
#include <bsd_auth.h>
#ifdef KRB5
#include <krb5.h>
#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;
auth_session_t *as;
#ifdef KRB5
krb5_context krb5_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.
*/
struct authmethod_cfg {
const char *name;
const char *synonym;
int *enabled;
};
struct Authmethod {
struct authmethod_cfg *cfg;
int (*userauth)(struct ssh *, const char *);
};
/*
* 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_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 */
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);
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
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