1 /* 2 * Author: Tatu Ylonen <ylo@cs.hut.fi> 3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 4 * All rights reserved 5 * Password authentication. This file contains the functions to check whether 6 * the password is valid for the user. 7 * 8 * As far as I am concerned, the code I have written for this software 9 * can be used freely for any purpose. Any derived versions of this 10 * software must be clearly marked as such, and if the derived work is 11 * incompatible with the protocol description in the RFC file, it must be 12 * called by a name other than "ssh" or "Secure Shell". 13 * 14 * Copyright (c) 1999 Dug Song. All rights reserved. 15 * Copyright (c) 2000 Markus Friedl. All rights reserved. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions 19 * are met: 20 * 1. Redistributions of source code must retain the above copyright 21 * notice, this list of conditions and the following disclaimer. 22 * 2. Redistributions in binary form must reproduce the above copyright 23 * notice, this list of conditions and the following disclaimer in the 24 * documentation and/or other materials provided with the distribution. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 29 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 30 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 31 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 35 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 36 */ 37 38 #include "includes.h" 39 RCSID("$OpenBSD: auth-passwd.c,v 1.31 2004/01/30 09:48:57 markus Exp $"); 40 RCSID("$FreeBSD$"); 41 42 #include "packet.h" 43 #include "log.h" 44 #include "servconf.h" 45 #include "auth.h" 46 #include "auth-options.h" 47 48 extern ServerOptions options; 49 int sys_auth_passwd(Authctxt *, const char *); 50 51 void 52 disable_forwarding(void) 53 { 54 no_port_forwarding_flag = 1; 55 no_agent_forwarding_flag = 1; 56 no_x11_forwarding_flag = 1; 57 } 58 59 /* 60 * Tries to authenticate the user using password. Returns true if 61 * authentication succeeds. 62 */ 63 int 64 auth_password(Authctxt *authctxt, const char *password) 65 { 66 struct passwd * pw = authctxt->pw; 67 int ok = authctxt->valid; 68 static int expire_checked = 0; 69 70 #ifndef HAVE_CYGWIN 71 if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES) 72 ok = 0; 73 #endif 74 if (*password == '\0' && options.permit_empty_passwd == 0) 75 return 0; 76 77 #ifdef KRB5 78 if (options.kerberos_authentication == 1) { 79 int ret = auth_krb5_password(authctxt, password); 80 if (ret == 1 || ret == 0) 81 return ret && ok; 82 /* Fall back to ordinary passwd authentication. */ 83 } 84 #endif 85 #ifdef HAVE_CYGWIN 86 if (is_winnt) { 87 HANDLE hToken = cygwin_logon_user(pw, password); 88 89 if (hToken == INVALID_HANDLE_VALUE) 90 return 0; 91 cygwin_set_impersonation_token(hToken); 92 return ok; 93 } 94 #endif 95 #if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE) 96 if (!expire_checked) { 97 expire_checked = 1; 98 if (auth_shadow_pwexpired(authctxt)) { 99 disable_forwarding(); 100 authctxt->force_pwchange = 1; 101 } 102 } 103 #endif 104 105 return (sys_auth_passwd(authctxt, password) && ok); 106 } 107 108 #ifdef BSD_AUTH 109 int 110 sys_auth_passwd(Authctxt *authctxt, const char *password) 111 { 112 struct passwd *pw = authctxt->pw; 113 auth_session_t *as; 114 115 as = auth_usercheck(pw->pw_name, authctxt->style, "auth-ssh", 116 (char *)password); 117 if (auth_getstate(as) & AUTH_PWEXPIRED) { 118 auth_close(as); 119 disable_forwarding(); 120 authctxt->force_pwchange = 1; 121 return (1); 122 } else { 123 return (auth_close(as)); 124 } 125 } 126 #elif !defined(CUSTOM_SYS_AUTH_PASSWD) 127 int 128 sys_auth_passwd(Authctxt *authctxt, const char *password) 129 { 130 struct passwd *pw = authctxt->pw; 131 char *encrypted_password; 132 133 /* Just use the supplied fake password if authctxt is invalid */ 134 char *pw_password = authctxt->valid ? shadow_pw(pw) : pw->pw_passwd; 135 136 /* Check for users with no password. */ 137 if (strcmp(pw_password, "") == 0 && strcmp(password, "") == 0) 138 return (1); 139 140 /* Encrypt the candidate password using the proper salt. */ 141 encrypted_password = xcrypt(password, 142 (pw_password[0] && pw_password[1]) ? pw_password : "xx"); 143 144 /* 145 * Authentication is accepted if the encrypted passwords 146 * are identical. 147 */ 148 return (strcmp(encrypted_password, pw_password) == 0); 149 } 150 #endif 151