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Diffstat (limited to 'auth.h')
| -rw-r--r-- | auth.h | 240 |
1 files changed, 240 insertions, 0 deletions
@@ -0,0 +1,240 @@ +/* $OpenBSD: auth.h,v 1.100 2019/09/06 05:23:55 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 <signal.h> + +#ifdef HAVE_LOGIN_CAP +#include <login_cap.h> +#endif +#ifdef BSD_AUTH +#include <bsd_auth.h> +#endif +#ifdef KRB5 +#include <krb5.h> +#endif + +struct passwd; +struct ssh; +struct sshbuf; +struct sshkey; +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_ccache krb5_fwd_ccache; + krb5_principal krb5_user; + char *krb5_ticket_file; + char *krb5_ccname; +#endif + struct sshbuf *loginmsg; + + /* 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 { + char *name; + int (*userauth)(struct ssh *); + 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 *, 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(Authctxt *authctxt, 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 */ + +#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE) +#include <shadow.h> +int auth_shadow_acctexpired(struct spwd *); +int auth_shadow_pwexpired(Authctxt *); +#endif + +#include "auth-pam.h" +#include "audit.h" +void remove_kbdint_device(const char *); + +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 *); + +FILE *auth_openkeyfile(const char *, struct passwd *, int); +FILE *auth_openprincipals(const char *, struct passwd *, int); +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 *); +int auth_authorise_keyopts(struct ssh *, struct passwd *pw, + struct sshauthopt *, int, const char *); +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); + +#define SSH_SUBPROCESS_STDOUT_DISCARD (1) /* Discard stdout */ +#define SSH_SUBPROCESS_STDOUT_CAPTURE (1<<1) /* Redirect stdout */ +#define SSH_SUBPROCESS_STDERR_DISCARD (1<<2) /* Discard stderr */ +pid_t subprocess(const char *, struct passwd *, + const char *, int, char **, FILE **, u_int flags); + +int sys_auth_passwd(struct ssh *, const char *); + +#if defined(KRB5) && !defined(HEIMDAL) +krb5_error_code ssh_krb5_cc_gen(krb5_context, krb5_ccache *); +#endif + +#endif /* AUTH_H */ |