X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/caf3bc51964a9fa7b36aadbd11d35cecf665db21..HEAD:/auth-passwd.c diff --git a/auth-passwd.c b/auth-passwd.c index bebd6389..b1c6ce09 100644 --- a/auth-passwd.c +++ b/auth-passwd.c @@ -1,218 +1,214 @@ +/* $OpenBSD: auth-passwd.c,v 1.43 2007/09/21 08:15:29 djm Exp $ */ /* - -auth-passwd.c - -Author: Tatu Ylonen - -Copyright (c) 1995 Tatu Ylonen , Espoo, Finland - All rights reserved - -Created: Sat Mar 18 05:11:38 1995 ylo - -Password authentication. This file contains the functions to check whether -the password is valid for the user. - -*/ + * Author: Tatu Ylonen + * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland + * All rights reserved + * Password authentication. This file contains the functions to check whether + * the password is valid for the user. + * + * As far as I am concerned, the code I have written for this software + * can be used freely for any purpose. Any derived versions of this + * software must be clearly marked as such, and if the derived work is + * incompatible with the protocol description in the RFC file, it must be + * called by a name other than "ssh" or "Secure Shell". + * + * Copyright (c) 1999 Dug Song. All rights reserved. + * Copyright (c) 2000 Markus Friedl. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ #include "includes.h" -#ifndef HAVE_PAM +#include -RCSID("$Id$"); +#include +#include +#include +#include #include "packet.h" -#include "ssh.h" +#include "buffer.h" +#include "log.h" #include "servconf.h" -#include "xmalloc.h" -#include "config.h" +#include "key.h" +#include "hostfile.h" +#include "auth.h" +#include "auth-options.h" -#ifdef HAVE_SHADOW_H -#include -#endif +extern Buffer loginmsg; +extern ServerOptions options; -#ifdef HAVE_MD5_PASSWORDS -#include "md5crypt.h" +#ifdef HAVE_LOGIN_CAP +extern login_cap_t *lc; #endif -/* Don't need anything from here if we are using PAM */ -/* Tries to authenticate the user using password. Returns true if - authentication succeeds. */ +#define DAY (24L * 60 * 60) /* 1 day in seconds */ +#define TWO_WEEKS (2L * 7 * DAY) /* 2 weeks in seconds */ -int auth_password(struct passwd *pw, const char *password) +void +disable_forwarding(void) { - extern ServerOptions options; - char *encrypted_password; -#ifdef HAVE_SHADOW_H - struct spwd *spw; -#endif + no_port_forwarding_flag = 1; + no_agent_forwarding_flag = 1; + no_x11_forwarding_flag = 1; +} - if (pw->pw_uid == 0 && options.permit_root_login == 2) - { - /*packet_send_debug("Server does not permit root login with password.");*/ - return 0; - } - - if (*password == '\0' && options.permit_empty_passwd == 0) - { - /*packet_send_debug("Server does not permit empty password login.");*/ - return 0; - } - - /* deny if no user. */ - if (pw == NULL) - return 0; - -#ifdef SKEY - if (options.skey_authentication == 1) { - if (strncasecmp(password, "s/key", 5) == 0) { - char *skeyinfo = skey_keyinfo(pw->pw_name); - if(skeyinfo == NULL){ - debug("generating fake skeyinfo for %.100s.", pw->pw_name); - skeyinfo = skey_fake_keyinfo(pw->pw_name); - } - if(skeyinfo != NULL) - packet_send_debug(skeyinfo); - /* Try again. */ - return 0; - } - else if (skey_haskey(pw->pw_name) == 0 && - skey_passcheck(pw->pw_name, (char *)password) != -1) { - /* Authentication succeeded. */ - return 1; - } - /* Fall back to ordinary passwd authentication. */ - } +/* + * Tries to authenticate the user using password. Returns true if + * authentication succeeds. + */ +int +auth_password(Authctxt *authctxt, const char *password) +{ + struct passwd * pw = authctxt->pw; + int result, ok = authctxt->valid; +#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE) + static int expire_checked = 0; #endif -#if defined(KRB4) - /* Support for Kerberos v4 authentication - Dug Song */ - if (options.kerberos_authentication) - { - AUTH_DAT adata; - KTEXT_ST tkt; - struct hostent *hp; - unsigned long faddr; - char localhost[MAXHOSTNAMELEN]; - char phost[INST_SZ]; - char realm[REALM_SZ]; - int r; - - /* Try Kerberos password authentication only for non-root - users and only if Kerberos is installed. */ - if (pw->pw_uid != 0 && krb_get_lrealm(realm, 1) == KSUCCESS) { - - /* Set up our ticket file. */ - if (!krb4_init(pw->pw_uid)) { - log("Couldn't initialize Kerberos ticket file for %s!", pw->pw_name); - goto kerberos_auth_failure; +#ifndef HAVE_CYGWIN + if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES) + ok = 0; +#endif + if (*password == '\0' && options.permit_empty_passwd == 0) + return 0; + +#ifdef KRB5 + if (options.kerberos_authentication == 1) { + int ret = auth_krb5_password(authctxt, password); + if (ret == 1 || ret == 0) + return ret && ok; + /* Fall back to ordinary passwd authentication. */ } - /* Try to get TGT using our password. */ - r = krb_get_pw_in_tkt((char *)pw->pw_name, "", realm, "krbtgt", realm, - DEFAULT_TKT_LIFE, (char *)password); - if (r != INTK_OK) { - packet_send_debug("Kerberos V4 password authentication for %s " - "failed: %s", pw->pw_name, krb_err_txt[r]); - goto kerberos_auth_failure; +#endif +#ifdef HAVE_CYGWIN + { + HANDLE hToken = cygwin_logon_user(pw, password); + + if (hToken == INVALID_HANDLE_VALUE) + return 0; + cygwin_set_impersonation_token(hToken); + return ok; } - /* Successful authentication. */ - chown(tkt_string(), pw->pw_uid, pw->pw_gid); - - /* Now that we have a TGT, try to get a local "rcmd" ticket to - ensure that we are not talking to a bogus Kerberos server. */ - (void) gethostname(localhost, sizeof(localhost)); - (void) strlcpy(phost, (char *)krb_get_phost(localhost), INST_SZ); - r = krb_mk_req(&tkt, KRB4_SERVICE_NAME, phost, realm, 33); - - if (r == KSUCCESS) { - if (!(hp = gethostbyname(localhost))) { - log("Couldn't get local host address!"); - goto kerberos_auth_failure; - } - memmove((void *)&faddr, (void *)hp->h_addr, sizeof(faddr)); - - /* Verify our "rcmd" ticket. */ - r = krb_rd_req(&tkt, KRB4_SERVICE_NAME, phost, faddr, &adata, ""); - if (r == RD_AP_UNDEC) { - /* Probably didn't have a srvtab on localhost. Allow login. */ - log("Kerberos V4 TGT for %s unverifiable, no srvtab installed? " - "krb_rd_req: %s", pw->pw_name, krb_err_txt[r]); - } - else if (r != KSUCCESS) { - log("Kerberos V4 %s ticket unverifiable: %s", - KRB4_SERVICE_NAME, krb_err_txt[r]); - goto kerberos_auth_failure; - } +#endif +#ifdef USE_PAM + if (options.use_pam) + return (sshpam_auth_passwd(authctxt, password) && ok); +#endif +#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE) + if (!expire_checked) { + expire_checked = 1; + if (auth_shadow_pwexpired(authctxt)) + authctxt->force_pwchange = 1; } - else if (r == KDC_PR_UNKNOWN) { - /* Allow login if no rcmd service exists, but log the error. */ - log("Kerberos V4 TGT for %s unverifiable: %s; %s.%s " - "not registered, or srvtab is wrong?", pw->pw_name, - krb_err_txt[r], KRB4_SERVICE_NAME, phost); +#endif + result = sys_auth_passwd(authctxt, password); + if (authctxt->force_pwchange) + disable_forwarding(); + return (result && ok); +} + +#ifdef BSD_AUTH +static void +warn_expiry(Authctxt *authctxt, auth_session_t *as) +{ + char buf[256]; + quad_t pwtimeleft, actimeleft, daysleft, pwwarntime, acwarntime; + + pwwarntime = acwarntime = TWO_WEEKS; + + pwtimeleft = auth_check_change(as); + actimeleft = auth_check_expire(as); +#ifdef HAVE_LOGIN_CAP + if (authctxt->valid) { + pwwarntime = login_getcaptime(lc, "password-warn", TWO_WEEKS, + TWO_WEEKS); + acwarntime = login_getcaptime(lc, "expire-warn", TWO_WEEKS, + TWO_WEEKS); + } +#endif + if (pwtimeleft != 0 && pwtimeleft < pwwarntime) { + daysleft = pwtimeleft / DAY + 1; + snprintf(buf, sizeof(buf), + "Your password will expire in %lld day%s.\n", + daysleft, daysleft == 1 ? "" : "s"); + buffer_append(&loginmsg, buf, strlen(buf)); } - else { - /* TGT is bad, forget it. Possibly spoofed! */ - packet_send_debug("WARNING: Kerberos V4 TGT possibly spoofed for" - "%s: %s", pw->pw_name, krb_err_txt[r]); - goto kerberos_auth_failure; + if (actimeleft != 0 && actimeleft < acwarntime) { + daysleft = actimeleft / DAY + 1; + snprintf(buf, sizeof(buf), + "Your account will expire in %lld day%s.\n", + daysleft, daysleft == 1 ? "" : "s"); + buffer_append(&loginmsg, buf, strlen(buf)); } - - /* Authentication succeeded. */ - return 1; - - kerberos_auth_failure: - krb4_cleanup_proc(NULL); - - if (!options.kerberos_or_local_passwd) - return 0; - } - else { - /* Logging in as root or no local Kerberos realm. */ - packet_send_debug("Unable to authenticate to Kerberos."); - } - /* Fall back to ordinary passwd authentication. */ - } -#endif /* KRB4 */ - - /* Check for users with no password. */ - if (strcmp(password, "") == 0 && strcmp(pw->pw_passwd, "") == 0) - { - packet_send_debug("Login permitted without a password because the account has no password."); - return 1; /* The user has no password and an empty password was tried. */ - } - -#ifdef HAVE_SHADOW_H - spw = getspnam(pw->pw_name); - if (spw == NULL) - return(0); - - if ((spw->sp_namp == NULL) || (strcmp(pw->pw_name, spw->sp_namp) != 0)) - fatal("Shadow lookup returned garbage."); - - if (strlen(spw->sp_pwdp) < 3) - return(0); - - /* Encrypt the candidate password using the proper salt. */ -#ifdef HAVE_MD5_PASSWORDS - if (is_md5_salt(spw->sp_pwdp)) - encrypted_password = md5_crypt(password, spw->sp_pwdp); - else - encrypted_password = crypt(password, spw->sp_pwdp); -#else /* HAVE_MD5_PASSWORDS */ - encrypted_password = crypt(password, spw->sp_pwdp); -#endif /* HAVE_MD5_PASSWORDS */ - - /* Authentication is accepted if the encrypted passwords are identical. */ - return (strcmp(encrypted_password, spw->sp_pwdp) == 0); -#else /* !HAVE_SHADOW_H */ - - /* Encrypt the candidate password using the proper salt. */ - encrypted_password = crypt(password, - (pw->pw_passwd[0] && pw->pw_passwd[1]) ? - pw->pw_passwd : "xx"); - /* Authentication is accepted if the encrypted passwords are identical. */ - return (strcmp(encrypted_password, pw->pw_passwd) == 0); -#endif /* !HAVE_SHADOW_H */ } -#endif /* !HAVE_PAM */ +int +sys_auth_passwd(Authctxt *authctxt, const char *password) +{ + struct passwd *pw = authctxt->pw; + auth_session_t *as; + static int expire_checked = 0; + + as = auth_usercheck(pw->pw_name, authctxt->style, "auth-ssh", + (char *)password); + if (as == NULL) + return (0); + if (auth_getstate(as) & AUTH_PWEXPIRED) { + auth_close(as); + disable_forwarding(); + authctxt->force_pwchange = 1; + return (1); + } else { + if (!expire_checked) { + expire_checked = 1; + warn_expiry(authctxt, as); + } + return (auth_close(as)); + } +} +#elif !defined(CUSTOM_SYS_AUTH_PASSWD) +int +sys_auth_passwd(Authctxt *authctxt, const char *password) +{ + struct passwd *pw = authctxt->pw; + char *encrypted_password; + + /* Just use the supplied fake password if authctxt is invalid */ + char *pw_password = authctxt->valid ? shadow_pw(pw) : pw->pw_passwd; + + /* Check for users with no password. */ + if (strcmp(pw_password, "") == 0 && strcmp(password, "") == 0) + return (1); + + /* Encrypt the candidate password using the proper salt. */ + encrypted_password = xcrypt(password, + (pw_password[0] && pw_password[1]) ? pw_password : "xx"); + + /* + * Authentication is accepted if the encrypted passwords + * are identical. + */ + return (strcmp(encrypted_password, pw_password) == 0); +} +#endif