1 /* $NetBSD: auth-passwd.c,v 1.2 2009/06/07 22:38:46 christos Exp $ */ 2 /* $OpenBSD: auth-passwd.c,v 1.43 2007/09/21 08:15:29 djm Exp $ */ 3 /* 4 * Author: Tatu Ylonen <ylo@cs.hut.fi> 5 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 6 * All rights reserved 7 * Password authentication. This file contains the functions to check whether 8 * the password is valid for the user. 9 * 10 * As far as I am concerned, the code I have written for this software 11 * can be used freely for any purpose. Any derived versions of this 12 * software must be clearly marked as such, and if the derived work is 13 * incompatible with the protocol description in the RFC file, it must be 14 * called by a name other than "ssh" or "Secure Shell". 15 * 16 * Copyright (c) 1999 Dug Song. All rights reserved. 17 * Copyright (c) 2000 Markus Friedl. All rights reserved. 18 * 19 * Redistribution and use in source and binary forms, with or without 20 * modification, are permitted provided that the following conditions 21 * are met: 22 * 1. Redistributions of source code must retain the above copyright 23 * notice, this list of conditions and the following disclaimer. 24 * 2. Redistributions in binary form must reproduce the above copyright 25 * notice, this list of conditions and the following disclaimer in the 26 * documentation and/or other materials provided with the distribution. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 29 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 30 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 31 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 32 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 33 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 37 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 #include "includes.h" 41 __RCSID("$NetBSD: auth-passwd.c,v 1.2 2009/06/07 22:38:46 christos Exp $"); 42 #include <sys/types.h> 43 44 #include <login_cap.h> 45 #include <pwd.h> 46 #include <stdio.h> 47 #include <string.h> 48 #include <stdarg.h> 49 #include <unistd.h> 50 51 #include "packet.h" 52 #include "buffer.h" 53 #include "log.h" 54 #include "servconf.h" 55 #include "key.h" 56 #include "hostfile.h" 57 #include "auth.h" 58 #include "auth-options.h" 59 60 extern Buffer loginmsg; 61 extern ServerOptions options; 62 int sys_auth_passwd(Authctxt *, const char *); 63 64 #ifdef HAVE_LOGIN_CAP 65 extern login_cap_t *lc; 66 #endif 67 68 #define DAY (24L * 60 * 60) /* 1 day in seconds */ 69 #define TWO_WEEKS (2L * 7 * DAY) /* 2 weeks in seconds */ 70 71 #if defined(BSD_AUTH) || defined(USE_PAM) 72 void 73 disable_forwarding(void) 74 { 75 no_port_forwarding_flag = 1; 76 no_agent_forwarding_flag = 1; 77 no_x11_forwarding_flag = 1; 78 } 79 #endif 80 81 /* 82 * Tries to authenticate the user using password. Returns true if 83 * authentication succeeds. 84 */ 85 int 86 auth_password(Authctxt *authctxt, const char *password) 87 { 88 struct passwd * pw = authctxt->pw; 89 int ok = authctxt->valid; 90 91 if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES) 92 ok = 0; 93 if (*password == '\0' && options.permit_empty_passwd == 0) 94 return 0; 95 #ifdef USE_PAM 96 if (options.use_pam) 97 return (sshpam_auth_passwd(authctxt, password) && ok); 98 #endif 99 #ifdef KRB5 100 if (options.kerberos_authentication == 1) { 101 int ret = auth_krb5_password(authctxt, password); 102 if (ret == 1 || ret == 0) 103 return ret && ok; 104 /* Fall back to ordinary passwd authentication. */ 105 } 106 #endif 107 return (sys_auth_passwd(authctxt, password) && ok); 108 } 109 110 #ifdef BSD_AUTH 111 static void 112 warn_expiry(Authctxt *authctxt, auth_session_t *as) 113 { 114 char buf[256]; 115 quad_t pwtimeleft, actimeleft, daysleft, pwwarntime, acwarntime; 116 117 pwwarntime = acwarntime = TWO_WEEKS; 118 119 pwtimeleft = auth_check_change(as); 120 actimeleft = auth_check_expire(as); 121 #ifdef HAVE_LOGIN_CAP 122 if (authctxt->valid) { 123 pwwarntime = login_getcaptime(lc, "password-warn", TWO_WEEKS, 124 TWO_WEEKS); 125 acwarntime = login_getcaptime(lc, "expire-warn", TWO_WEEKS, 126 TWO_WEEKS); 127 } 128 #endif 129 if (pwtimeleft != 0 && pwtimeleft < pwwarntime) { 130 daysleft = pwtimeleft / DAY + 1; 131 snprintf(buf, sizeof(buf), 132 "Your password will expire in %lld day%s.\n", 133 daysleft, daysleft == 1 ? "" : "s"); 134 buffer_append(&loginmsg, buf, strlen(buf)); 135 } 136 if (actimeleft != 0 && actimeleft < acwarntime) { 137 daysleft = actimeleft / DAY + 1; 138 snprintf(buf, sizeof(buf), 139 "Your account will expire in %lld day%s.\n", 140 daysleft, daysleft == 1 ? "" : "s"); 141 buffer_append(&loginmsg, buf, strlen(buf)); 142 } 143 } 144 145 int 146 sys_auth_passwd(Authctxt *authctxt, const char *password) 147 { 148 struct passwd *pw = authctxt->pw; 149 auth_session_t *as; 150 static int expire_checked = 0; 151 152 as = auth_usercheck(pw->pw_name, authctxt->style, "auth-ssh", 153 (char *)password); 154 if (as == NULL) 155 return (0); 156 if (auth_getstate(as) & AUTH_PWEXPIRED) { 157 auth_close(as); 158 disable_forwarding(); 159 authctxt->force_pwchange = 1; 160 return (1); 161 } else { 162 if (!expire_checked) { 163 expire_checked = 1; 164 warn_expiry(authctxt, as); 165 } 166 return (auth_close(as)); 167 } 168 } 169 #else 170 int 171 sys_auth_passwd(Authctxt *authctxt, const char *password) 172 { 173 struct passwd *pw = authctxt->pw; 174 char *encrypted_password; 175 176 /* Check for users with no password. */ 177 if (strcmp(password, "") == 0 && strcmp(pw->pw_passwd, "") == 0) 178 return (1); 179 180 /* Encrypt the candidate password using the proper salt. */ 181 encrypted_password = crypt(password, 182 (pw->pw_passwd[0] && pw->pw_passwd[1]) ? 183 pw->pw_passwd : "xx"); 184 185 /* 186 * Authentication is accepted if the encrypted passwords 187 * are identical. 188 */ 189 return (strcmp(encrypted_password, pw->pw_passwd) == 0); 190 } 191 #endif 192