Annotation of src/usr.bin/ssh/auth.h, Revision 1.99
1.99 ! djm 1: /* $OpenBSD: auth.h,v 1.98 2019/01/19 21:41:18 djm Exp $ */
1.29 stevesk 2:
1.5 deraadt 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.
1.7 djm 25: *
1.5 deraadt 26: */
1.29 stevesk 27:
1.1 markus 28: #ifndef AUTH_H
29: #define AUTH_H
30:
1.57 deraadt 31: #include <signal.h>
1.54 stevesk 32:
1.10 markus 33: #include <openssl/rsa.h>
34:
1.13 markus 35: #include <bsd_auth.h>
1.21 dugsong 36: #ifdef KRB5
37: #include <krb5.h>
38: #endif
1.13 markus 39:
1.95 djm 40: struct passwd;
1.80 markus 41: struct ssh;
1.95 djm 42: struct sshbuf;
1.79 djm 43: struct sshkey;
1.95 djm 44: struct sshauthopt;
1.79 djm 45:
1.6 markus 46: typedef struct Authctxt Authctxt;
1.39 markus 47: typedef struct Authmethod Authmethod;
1.16 markus 48: typedef struct KbdintDevice KbdintDevice;
49:
1.6 markus 50: struct Authctxt {
1.53 djm 51: sig_atomic_t success;
1.58 markus 52: int authenticated; /* authenticated and alarms cancelled */
1.42 markus 53: int postponed; /* authentication needs another step */
54: int valid; /* user exists and is allowed to login */
1.21 dugsong 55: int attempt;
56: int failures;
1.84 djm 57: int server_caused_failure;
1.49 markus 58: int force_pwchange;
1.42 markus 59: char *user; /* username sent by the client */
1.21 dugsong 60: char *service;
1.42 markus 61: struct passwd *pw; /* set if 'valid' */
1.21 dugsong 62: char *style;
1.92 djm 63:
64: /* Method lists for multiple authentication */
65: char **auth_methods; /* modified from server config */
66: u_int num_auth_methods;
67:
68: /* Authentication method-specific data */
69: void *methoddata;
1.21 dugsong 70: void *kbdintctxt;
71: auth_session_t *as;
72: #ifdef KRB5
73: krb5_context krb5_ctx;
74: krb5_ccache krb5_fwd_ccache;
75: krb5_principal krb5_user;
76: char *krb5_ticket_file;
1.13 markus 77: #endif
1.79 djm 78:
1.92 djm 79: /* Authentication keys already used; these will be refused henceforth */
80: struct sshkey **prev_keys;
81: u_int nprev_keys;
82:
1.96 djm 83: /* Last used key and ancillary information from active auth method */
1.92 djm 84: struct sshkey *auth_method_key;
85: char *auth_method_info;
86:
87: /* Information exposed to session */
88: struct sshbuf *session_info; /* Auth info for environment */
1.6 markus 89: };
1.92 djm 90:
1.42 markus 91: /*
92: * Every authentication method has to handle authentication requests for
93: * non-existing users, or for users that are not allowed to login. In this
94: * case 'valid' is set to 0, but 'user' points to the username requested by
95: * the client.
96: */
1.10 markus 97:
1.39 markus 98: struct Authmethod {
99: char *name;
1.91 markus 100: int (*userauth)(struct ssh *);
1.39 markus 101: int *enabled;
102: };
103:
1.10 markus 104: /*
1.16 markus 105: * Keyboard interactive device:
1.25 deraadt 106: * init_ctx returns: non NULL upon success
107: * query returns: 0 - success, otherwise failure
1.16 markus 108: * respond returns: 0 - success, 1 - need further interaction,
109: * otherwise - failure
110: */
111: struct KbdintDevice
112: {
113: const char *name;
1.27 millert 114: void* (*init_ctx)(Authctxt*);
1.28 millert 115: int (*query)(void *ctx, char **name, char **infotxt,
116: u_int *numprompts, char ***prompts, u_int **echo_on);
1.27 millert 117: int (*respond)(void *ctx, u_int numresp, char **responses);
118: void (*free_ctx)(void *ctx);
1.16 markus 119: };
120:
1.15 markus 121: int
1.20 itojun 122: auth_rhosts2(struct passwd *, const char *, const char *, const char *);
1.10 markus 123:
1.95 djm 124: int auth_password(struct ssh *, const char *);
1.35 markus 125:
1.99 ! djm 126: int hostbased_key_allowed(struct ssh *, struct passwd *,
! 127: const char *, char *, struct sshkey *);
1.95 djm 128: int user_key_allowed(struct ssh *, struct passwd *, struct sshkey *, int,
129: struct sshauthopt **);
1.92 djm 130: int auth2_key_already_used(Authctxt *, const struct sshkey *);
131:
132: /*
133: * Handling auth method-specific information for logging and prevention
134: * of key reuse during multiple authentication.
135: */
136: void auth2_authctxt_reset_info(Authctxt *);
137: void auth2_record_key(Authctxt *, int, const struct sshkey *);
138: void auth2_record_info(Authctxt *authctxt, const char *, ...)
139: __attribute__((__format__ (printf, 2, 3)))
140: __attribute__((__nonnull__ (2)));
141: void auth2_update_session_info(Authctxt *, const char *, const char *);
1.21 dugsong 142:
143: #ifdef KRB5
1.40 itojun 144: int auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *);
1.21 dugsong 145: int auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt);
146: int auth_krb5_password(Authctxt *authctxt, const char *password);
1.47 markus 147: void krb5_cleanup_proc(Authctxt *authctxt);
1.21 dugsong 148: #endif /* KRB5 */
1.6 markus 149:
1.97 djm 150: void do_authentication2(struct ssh *);
1.2 markus 151:
1.98 djm 152: void auth_log(struct ssh *, int, int, const char *, const char *);
153: void auth_maxtries_exceeded(struct ssh *) __attribute__((noreturn));
1.91 markus 154: void userauth_finish(struct ssh *, int, const char *, const char *);
1.95 djm 155: int auth_root_allowed(struct ssh *, const char *);
1.36 djm 156:
157: char *auth2_read_banner(void);
1.71 djm 158: int auth2_methods_valid(const char *, int);
1.73 markus 159: int auth2_update_methods_lists(Authctxt *, const char *, const char *);
1.71 djm 160: int auth2_setup_methods_lists(Authctxt *);
1.73 markus 161: int auth2_method_allowed(Authctxt *, const char *, const char *);
1.6 markus 162:
1.34 provos 163: void privsep_challenge_enable(void);
164:
1.91 markus 165: int auth2_challenge(struct ssh *, char *);
166: void auth2_challenge_stop(struct ssh *);
1.35 markus 167: int bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **);
168: int bsdauth_respond(void *, u_int, char **);
1.1 markus 169:
1.98 djm 170: int allowed_user(struct ssh *, struct passwd *);
171: struct passwd * getpwnamallow(struct ssh *, const char *user);
1.9 markus 172:
1.69 djm 173: char *expand_authorized_keys(const char *, struct passwd *pw);
1.66 djm 174: char *authorized_principals_file(struct passwd *);
1.17 markus 175:
1.61 dtucker 176: FILE *auth_openkeyfile(const char *, struct passwd *, int);
1.66 djm 177: FILE *auth_openprincipals(const char *, struct passwd *, int);
1.90 markus 178: int auth_key_is_revoked(struct sshkey *);
1.87 djm 179:
180: const char *auth_get_canonical_hostname(struct ssh *, int);
1.18 markus 181:
182: HostStatus
1.90 markus 183: check_key_in_hostfiles(struct passwd *, struct sshkey *, const char *,
1.20 itojun 184: const char *, const char *);
1.35 markus 185:
186: /* hostkey handling */
1.90 markus 187: struct sshkey *get_hostkey_by_index(int);
188: struct sshkey *get_hostkey_public_by_index(int, struct ssh *);
189: struct sshkey *get_hostkey_public_by_type(int, int, struct ssh *);
190: struct sshkey *get_hostkey_private_by_type(int, int, struct ssh *);
191: int get_hostkey_index(struct sshkey *, int, struct ssh *);
1.99 ! djm 192: int sshd_hostkey_sign(struct ssh *, struct sshkey *, struct sshkey *,
! 193: u_char **, size_t *, const u_char *, size_t, const char *);
1.37 markus 194:
1.95 djm 195: /* Key / cert options linkage to auth layer */
196: const struct sshauthopt *auth_options(struct ssh *);
197: int auth_activate_options(struct ssh *, struct sshauthopt *);
198: void auth_restrict_session(struct ssh *);
199: int auth_authorise_keyopts(struct ssh *, struct passwd *pw,
200: struct sshauthopt *, int, const char *);
201: void auth_log_authopts(const char *, const struct sshauthopt *, int);
202:
1.37 markus 203: /* debug messages during authentication */
1.95 djm 204: void auth_debug_add(const char *fmt,...)
205: __attribute__((format(printf, 1, 2)));
1.98 djm 206: void auth_debug_send(struct ssh *);
1.37 markus 207: void auth_debug_reset(void);
1.45 markus 208:
209: struct passwd *fakepw(void);
1.94 markus 210:
211: #define SSH_SUBPROCESS_STDOUT_DISCARD (1) /* Discard stdout */
212: #define SSH_SUBPROCESS_STDOUT_CAPTURE (1<<1) /* Redirect stdout */
213: #define SSH_SUBPROCESS_STDERR_DISCARD (1<<2) /* Discard stderr */
214: pid_t subprocess(const char *, struct passwd *,
215: const char *, int, char **, FILE **, u_int flags);
1.3 markus 216:
1.1 markus 217: #endif