Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 1 | /* $OpenBSD: auth-passwd.c,v 1.44 2014/07/15 15:54:14 millert Exp $ */ |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 2 | /* |
| 3 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
| 4 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| 5 | * All rights reserved |
| 6 | * Password authentication. This file contains the functions to check whether |
| 7 | * the password is valid for the user. |
| 8 | * |
| 9 | * As far as I am concerned, the code I have written for this software |
| 10 | * can be used freely for any purpose. Any derived versions of this |
| 11 | * software must be clearly marked as such, and if the derived work is |
| 12 | * incompatible with the protocol description in the RFC file, it must be |
| 13 | * called by a name other than "ssh" or "Secure Shell". |
| 14 | * |
| 15 | * Copyright (c) 1999 Dug Song. All rights reserved. |
| 16 | * Copyright (c) 2000 Markus Friedl. All rights reserved. |
| 17 | * |
| 18 | * Redistribution and use in source and binary forms, with or without |
| 19 | * modification, are permitted provided that the following conditions |
| 20 | * are met: |
| 21 | * 1. Redistributions of source code must retain the above copyright |
| 22 | * notice, this list of conditions and the following disclaimer. |
| 23 | * 2. Redistributions in binary form must reproduce the above copyright |
| 24 | * notice, this list of conditions and the following disclaimer in the |
| 25 | * documentation and/or other materials provided with the distribution. |
| 26 | * |
| 27 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 28 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 29 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 30 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 31 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 32 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 33 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 34 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 35 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 36 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 37 | */ |
| 38 | |
| 39 | #include "includes.h" |
| 40 | |
| 41 | #include <sys/types.h> |
| 42 | |
| 43 | #include <pwd.h> |
| 44 | #include <stdio.h> |
| 45 | #include <string.h> |
| 46 | #include <stdarg.h> |
| 47 | |
| 48 | #include "packet.h" |
| 49 | #include "buffer.h" |
| 50 | #include "log.h" |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 51 | #include "misc.h" |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 52 | #include "servconf.h" |
| 53 | #include "key.h" |
| 54 | #include "hostfile.h" |
| 55 | #include "auth.h" |
| 56 | #include "auth-options.h" |
| 57 | |
| 58 | extern Buffer loginmsg; |
| 59 | extern ServerOptions options; |
| 60 | |
| 61 | #ifdef HAVE_LOGIN_CAP |
| 62 | extern login_cap_t *lc; |
| 63 | #endif |
| 64 | |
| 65 | |
| 66 | #define DAY (24L * 60 * 60) /* 1 day in seconds */ |
| 67 | #define TWO_WEEKS (2L * 7 * DAY) /* 2 weeks in seconds */ |
| 68 | |
| 69 | void |
| 70 | disable_forwarding(void) |
| 71 | { |
| 72 | no_port_forwarding_flag = 1; |
| 73 | no_agent_forwarding_flag = 1; |
| 74 | no_x11_forwarding_flag = 1; |
| 75 | } |
| 76 | |
| 77 | /* |
| 78 | * Tries to authenticate the user using password. Returns true if |
| 79 | * authentication succeeds. |
| 80 | */ |
| 81 | int |
| 82 | auth_password(Authctxt *authctxt, const char *password) |
| 83 | { |
| 84 | struct passwd * pw = authctxt->pw; |
| 85 | int result, ok = authctxt->valid; |
| 86 | #if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE) |
| 87 | static int expire_checked = 0; |
| 88 | #endif |
| 89 | |
| 90 | #ifndef HAVE_CYGWIN |
| 91 | if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES) |
| 92 | ok = 0; |
| 93 | #endif |
| 94 | if (*password == '\0' && options.permit_empty_passwd == 0) |
| 95 | return 0; |
| 96 | |
| 97 | #ifdef KRB5 |
| 98 | if (options.kerberos_authentication == 1) { |
| 99 | int ret = auth_krb5_password(authctxt, password); |
| 100 | if (ret == 1 || ret == 0) |
| 101 | return ret && ok; |
| 102 | /* Fall back to ordinary passwd authentication. */ |
| 103 | } |
| 104 | #endif |
| 105 | #ifdef HAVE_CYGWIN |
| 106 | { |
| 107 | HANDLE hToken = cygwin_logon_user(pw, password); |
| 108 | |
| 109 | if (hToken == INVALID_HANDLE_VALUE) |
| 110 | return 0; |
| 111 | cygwin_set_impersonation_token(hToken); |
| 112 | return ok; |
| 113 | } |
| 114 | #endif |
| 115 | #ifdef USE_PAM |
| 116 | if (options.use_pam) |
| 117 | return (sshpam_auth_passwd(authctxt, password) && ok); |
| 118 | #endif |
| 119 | #if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE) |
| 120 | if (!expire_checked) { |
| 121 | expire_checked = 1; |
| 122 | if (auth_shadow_pwexpired(authctxt)) |
| 123 | authctxt->force_pwchange = 1; |
| 124 | } |
| 125 | #endif |
| 126 | result = sys_auth_passwd(authctxt, password); |
| 127 | if (authctxt->force_pwchange) |
| 128 | disable_forwarding(); |
| 129 | return (result && ok); |
| 130 | } |
| 131 | |
| 132 | #ifdef BSD_AUTH |
| 133 | static void |
| 134 | warn_expiry(Authctxt *authctxt, auth_session_t *as) |
| 135 | { |
| 136 | char buf[256]; |
| 137 | quad_t pwtimeleft, actimeleft, daysleft, pwwarntime, acwarntime; |
| 138 | |
| 139 | pwwarntime = acwarntime = TWO_WEEKS; |
| 140 | |
| 141 | pwtimeleft = auth_check_change(as); |
| 142 | actimeleft = auth_check_expire(as); |
| 143 | #ifdef HAVE_LOGIN_CAP |
| 144 | if (authctxt->valid) { |
| 145 | pwwarntime = login_getcaptime(lc, "password-warn", TWO_WEEKS, |
| 146 | TWO_WEEKS); |
| 147 | acwarntime = login_getcaptime(lc, "expire-warn", TWO_WEEKS, |
| 148 | TWO_WEEKS); |
| 149 | } |
| 150 | #endif |
| 151 | if (pwtimeleft != 0 && pwtimeleft < pwwarntime) { |
| 152 | daysleft = pwtimeleft / DAY + 1; |
| 153 | snprintf(buf, sizeof(buf), |
| 154 | "Your password will expire in %lld day%s.\n", |
| 155 | daysleft, daysleft == 1 ? "" : "s"); |
| 156 | buffer_append(&loginmsg, buf, strlen(buf)); |
| 157 | } |
| 158 | if (actimeleft != 0 && actimeleft < acwarntime) { |
| 159 | daysleft = actimeleft / DAY + 1; |
| 160 | snprintf(buf, sizeof(buf), |
| 161 | "Your account will expire in %lld day%s.\n", |
| 162 | daysleft, daysleft == 1 ? "" : "s"); |
| 163 | buffer_append(&loginmsg, buf, strlen(buf)); |
| 164 | } |
| 165 | } |
| 166 | |
| 167 | int |
| 168 | sys_auth_passwd(Authctxt *authctxt, const char *password) |
| 169 | { |
| 170 | struct passwd *pw = authctxt->pw; |
| 171 | auth_session_t *as; |
| 172 | static int expire_checked = 0; |
| 173 | |
| 174 | as = auth_usercheck(pw->pw_name, authctxt->style, "auth-ssh", |
| 175 | (char *)password); |
| 176 | if (as == NULL) |
| 177 | return (0); |
| 178 | if (auth_getstate(as) & AUTH_PWEXPIRED) { |
| 179 | auth_close(as); |
| 180 | disable_forwarding(); |
| 181 | authctxt->force_pwchange = 1; |
| 182 | return (1); |
| 183 | } else { |
| 184 | if (!expire_checked) { |
| 185 | expire_checked = 1; |
| 186 | warn_expiry(authctxt, as); |
| 187 | } |
| 188 | return (auth_close(as)); |
| 189 | } |
| 190 | } |
| 191 | #elif !defined(CUSTOM_SYS_AUTH_PASSWD) |
| 192 | int |
| 193 | sys_auth_passwd(Authctxt *authctxt, const char *password) |
| 194 | { |
| 195 | struct passwd *pw = authctxt->pw; |
| 196 | char *encrypted_password; |
| 197 | |
| 198 | /* Just use the supplied fake password if authctxt is invalid */ |
| 199 | char *pw_password = authctxt->valid ? shadow_pw(pw) : pw->pw_passwd; |
| 200 | |
| 201 | /* Check for users with no password. */ |
| 202 | if (strcmp(pw_password, "") == 0 && strcmp(password, "") == 0) |
| 203 | return (1); |
| 204 | |
| 205 | /* Encrypt the candidate password using the proper salt. */ |
| 206 | encrypted_password = xcrypt(password, |
| 207 | (pw_password[0] && pw_password[1]) ? pw_password : "xx"); |
| 208 | |
| 209 | /* |
| 210 | * Authentication is accepted if the encrypted passwords |
| 211 | * are identical. |
| 212 | */ |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 213 | return encrypted_password != NULL && |
| 214 | strcmp(encrypted_password, pw_password) == 0; |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 215 | } |
| 216 | #endif |