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 1.22 2001/03/20 18:57:04 markus Exp $"); 40 RCSID("$FreeBSD$"); 41 42 #include "packet.h" 43 #include "xmalloc.h" 44 #include "log.h" 45 #include "servconf.h" 46 #include "auth.h" 47 48 49 extern ServerOptions options; 50 51 /* 52 * Tries to authenticate the user using password. Returns true if 53 * authentication succeeds. 54 */ 55 int 56 auth_password(Authctxt *authctxt, const char *password) 57 { 58 struct passwd * pw = authctxt->pw; 59 char *encrypted_password; 60 61 /* deny if no user. */ 62 if (pw == NULL) 63 return 0; 64 if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES) 65 return 0; 66 if (*password == '\0' && options.permit_empty_passwd == 0) 67 return 0; 68 #ifdef BSD_AUTH 69 if (auth_userokay(pw->pw_name, authctxt->style, "auth-ssh", 70 (char *)password) == 0) 71 return 0; 72 else 73 return 1; 74 #endif 75 #ifdef KRB5 76 if (options.kerberos_authentication == 1) { 77 if (auth_krb5_password(pw, password)) 78 return 1; 79 /* Fall back to ordinary passwd authentication. */ 80 } 81 82 #endif /* KRB5 */ 83 #ifdef KRB4 84 if (options.kerberos_authentication == 1) { 85 int ret = auth_krb4_password(pw, password); 86 if (ret == 1 || ret == 0) 87 return ret; 88 /* Fall back to ordinary passwd authentication. */ 89 } 90 #endif 91 92 /* Check for users with no password. */ 93 if (strcmp(password, "") == 0 && strcmp(pw->pw_passwd, "") == 0) 94 return 1; 95 /* Encrypt the candidate password using the proper salt. */ 96 encrypted_password = crypt(password, 97 (pw->pw_passwd[0] && pw->pw_passwd[1]) ? pw->pw_passwd : "xx"); 98 99 /* Authentication is accepted if the encrypted passwords are identical. */ 100 return (strcmp(encrypted_password, pw->pw_passwd) == 0); 101 } 102