+/* $OpenBSD: auth-passwd.c,v 1.43 2007/09/21 08:15:29 djm Exp $ */
/*
-
-auth-passwd.c
-
-Author: Tatu Ylonen <ylo@cs.hut.fi>
-
-Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, 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 <ylo@cs.hut.fi>
+ * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, 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 <sys/types.h>
-RCSID("$Id$");
+#include <pwd.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdarg.h>
#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 <shadow.h>
-#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 <dugsong@UMICH.EDU> */
- 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
andersk / openssh.git / blobdiff