1 /* $OpenBSD: auth-passwd.c,v 1.47 2018/07/09 21:26:02 markus 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 "sshbuf.h" 49 #include "ssherr.h" 50 #include "log.h" 51 #include "misc.h" 52 #include "servconf.h" 53 #include "sshkey.h" 54 #include "hostfile.h" 55 #include "auth.h" 56 #include "auth-options.h" 57 58 extern struct sshbuf *loginmsg; 59 extern ServerOptions options; 60 int sys_auth_passwd(struct ssh *, const char *); 61 62 extern login_cap_t *lc; 63 64 #define DAY (24L * 60 * 60) /* 1 day in seconds */ 65 #define TWO_WEEKS (2L * 7 * DAY) /* 2 weeks in seconds */ 66 67 #define MAX_PASSWORD_LEN 1024 68 69 /* 70 * Tries to authenticate the user using password. Returns true if 71 * authentication succeeds. 72 */ 73 int 74 auth_password(struct ssh *ssh, const char *password) 75 { 76 Authctxt *authctxt = ssh->authctxt; 77 struct passwd *pw = authctxt->pw; 78 int ok = authctxt->valid; 79 80 if (strlen(password) > MAX_PASSWORD_LEN) 81 return 0; 82 83 if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES) 84 ok = 0; 85 if (*password == '\0' && options.permit_empty_passwd == 0) 86 return 0; 87 #ifdef KRB5 88 if (options.kerberos_authentication == 1) { 89 int ret = auth_krb5_password(authctxt, password); 90 if (ret == 1 || ret == 0) 91 return ret && ok; 92 /* Fall back to ordinary passwd authentication. */ 93 } 94 #endif 95 return (sys_auth_passwd(ssh, password) && ok); 96 } 97 98 static void 99 warn_expiry(Authctxt *authctxt, auth_session_t *as) 100 { 101 int r; 102 quad_t pwtimeleft, actimeleft, daysleft, pwwarntime, acwarntime; 103 104 pwwarntime = acwarntime = TWO_WEEKS; 105 106 pwtimeleft = auth_check_change(as); 107 actimeleft = auth_check_expire(as); 108 if (authctxt->valid) { 109 pwwarntime = login_getcaptime(lc, "password-warn", TWO_WEEKS, 110 TWO_WEEKS); 111 acwarntime = login_getcaptime(lc, "expire-warn", TWO_WEEKS, 112 TWO_WEEKS); 113 } 114 if (pwtimeleft != 0 && pwtimeleft < pwwarntime) { 115 daysleft = pwtimeleft / DAY + 1; 116 if ((r = sshbuf_putf(loginmsg, 117 "Your password will expire in %lld day%s.\n", 118 daysleft, daysleft == 1 ? "" : "s")) != 0) 119 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 120 } 121 if (actimeleft != 0 && actimeleft < acwarntime) { 122 daysleft = actimeleft / DAY + 1; 123 if ((r = sshbuf_putf(loginmsg, 124 "Your account will expire in %lld day%s.\n", 125 daysleft, daysleft == 1 ? "" : "s")) != 0) 126 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 127 } 128 } 129 130 int 131 sys_auth_passwd(struct ssh *ssh, const char *password) 132 { 133 Authctxt *authctxt = ssh->authctxt; 134 auth_session_t *as; 135 static int expire_checked = 0; 136 137 as = auth_usercheck(authctxt->pw->pw_name, authctxt->style, "auth-ssh", 138 (char *)password); 139 if (as == NULL) 140 return (0); 141 if (auth_getstate(as) & AUTH_PWEXPIRED) { 142 auth_close(as); 143 auth_restrict_session(ssh); 144 authctxt->force_pwchange = 1; 145 return (1); 146 } else { 147 if (!expire_checked) { 148 expire_checked = 1; 149 warn_expiry(authctxt, as); 150 } 151 return (auth_close(as)); 152 } 153 } 154