1 /* $OpenBSD: auth-passwd.c,v 1.45 2016/07/21 01:39:35 dtucker Exp $ */ 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 <sys/types.h> 40 41 #include <login_cap.h> 42 #include <pwd.h> 43 #include <stdio.h> 44 #include <string.h> 45 #include <stdarg.h> 46 47 #include "packet.h" 48 #include "buffer.h" 49 #include "log.h" 50 #include "misc.h" 51 #include "servconf.h" 52 #include "key.h" 53 #include "hostfile.h" 54 #include "auth.h" 55 #include "auth-options.h" 56 57 extern Buffer loginmsg; 58 extern ServerOptions options; 59 int sys_auth_passwd(Authctxt *, const char *); 60 61 extern login_cap_t *lc; 62 63 #define DAY (24L * 60 * 60) /* 1 day in seconds */ 64 #define TWO_WEEKS (2L * 7 * DAY) /* 2 weeks in seconds */ 65 66 #define MAX_PASSWORD_LEN 1024 67 68 static void 69 disable_forwarding(void) 70 { 71 no_port_forwarding_flag = 1; 72 no_agent_forwarding_flag = 1; 73 no_x11_forwarding_flag = 1; 74 } 75 76 /* 77 * Tries to authenticate the user using password. Returns true if 78 * authentication succeeds. 79 */ 80 int 81 auth_password(Authctxt *authctxt, const char *password) 82 { 83 struct passwd * pw = authctxt->pw; 84 int ok = authctxt->valid; 85 86 if (strlen(password) > MAX_PASSWORD_LEN) 87 return 0; 88 89 if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES) 90 ok = 0; 91 if (*password == '\0' && options.permit_empty_passwd == 0) 92 return 0; 93 #ifdef KRB5 94 if (options.kerberos_authentication == 1) { 95 int ret = auth_krb5_password(authctxt, password); 96 if (ret == 1 || ret == 0) 97 return ret && ok; 98 /* Fall back to ordinary passwd authentication. */ 99 } 100 #endif 101 return (sys_auth_passwd(authctxt, password) && ok); 102 } 103 104 static void 105 warn_expiry(Authctxt *authctxt, auth_session_t *as) 106 { 107 char buf[256]; 108 quad_t pwtimeleft, actimeleft, daysleft, pwwarntime, acwarntime; 109 110 pwwarntime = acwarntime = TWO_WEEKS; 111 112 pwtimeleft = auth_check_change(as); 113 actimeleft = auth_check_expire(as); 114 if (authctxt->valid) { 115 pwwarntime = login_getcaptime(lc, "password-warn", TWO_WEEKS, 116 TWO_WEEKS); 117 acwarntime = login_getcaptime(lc, "expire-warn", TWO_WEEKS, 118 TWO_WEEKS); 119 } 120 if (pwtimeleft != 0 && pwtimeleft < pwwarntime) { 121 daysleft = pwtimeleft / DAY + 1; 122 snprintf(buf, sizeof(buf), 123 "Your password will expire in %lld day%s.\n", 124 daysleft, daysleft == 1 ? "" : "s"); 125 buffer_append(&loginmsg, buf, strlen(buf)); 126 } 127 if (actimeleft != 0 && actimeleft < acwarntime) { 128 daysleft = actimeleft / DAY + 1; 129 snprintf(buf, sizeof(buf), 130 "Your account will expire in %lld day%s.\n", 131 daysleft, daysleft == 1 ? "" : "s"); 132 buffer_append(&loginmsg, buf, strlen(buf)); 133 } 134 } 135 136 int 137 sys_auth_passwd(Authctxt *authctxt, const char *password) 138 { 139 struct passwd *pw = authctxt->pw; 140 auth_session_t *as; 141 static int expire_checked = 0; 142 143 as = auth_usercheck(pw->pw_name, authctxt->style, "auth-ssh", 144 (char *)password); 145 if (as == NULL) 146 return (0); 147 if (auth_getstate(as) & AUTH_PWEXPIRED) { 148 auth_close(as); 149 disable_forwarding(); 150 authctxt->force_pwchange = 1; 151 return (1); 152 } else { 153 if (!expire_checked) { 154 expire_checked = 1; 155 warn_expiry(authctxt, as); 156 } 157 return (auth_close(as)); 158 } 159 } 160