/*
*
* Copyright (c) 2001 Gert Doering. All rights reserved.
* Copyright (c) 2003,2004,2005,2006 Darren Tucker. 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"
#include "xmalloc.h"
#include "buffer.h"
#include "key.h"
#include "hostfile.h"
#include "auth.h"
#include "ssh.h"
#include "log.h"
#ifdef _AIX
#include <errno.h>
#if defined(HAVE_NETDB_H)
# include <netdb.h>
#endif
#include <uinfo.h>
#include <stdarg.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#ifdef WITH_AIXAUTHENTICATE
# include <login.h>
# include <userpw.h>
# if defined(HAVE_SYS_AUDIT_H) && defined(AIX_LOGINFAILED_4ARG)
# include <sys/audit.h>
# endif
# include <usersec.h>
#endif
#include "port-aix.h"
static char *lastlogin_msg = NULL;
# ifdef HAVE_SETAUTHDB
static char old_registry[REGISTRY_SIZE] = "";
# endif
/*
* AIX has a "usrinfo" area where logname and other stuff is stored -
* a few applications actually use this and die if it's not set
*
* NOTE: TTY= should be set, but since no one uses it and it's hard to
* acquire due to privsep code. We will just drop support.
*/
void
aix_usrinfo(struct passwd *pw)
{
u_int i;
size_t len;
char *cp;
len = sizeof("LOGNAME= NAME= ") + (2 * strlen(pw->pw_name));
cp = xmalloc(len);
i = snprintf(cp, len, "LOGNAME=%s%cNAME=%s%c", pw->pw_name, '\0',
pw->pw_name, '\0');
if (usrinfo(SETUINFO, cp, i) == -1)
fatal("Couldn't set usrinfo: %s", strerror(errno));
debug3("AIX/UsrInfo: set len %d", i);
xfree(cp);
}
# ifdef WITH_AIXAUTHENTICATE
/*
* Remove embedded newlines in string (if any).
* Used before logging messages returned by AIX authentication functions
* so the message is logged on one line.
*/
void
aix_remove_embedded_newlines(char *p)
{
if (p == NULL)
return;
for (; *p; p++) {
if (*p == '\n')
*p = ' ';
}
/* Remove trailing whitespace */
if (*--p == ' ')
*p = '\0';
}
/*
* Test specifically for the case where SYSTEM == NONE and AUTH1 contains
* anything other than NONE or SYSTEM, which indicates that the admin has
* configured the account for purely AUTH1-type authentication.
*
* Since authenticate() doesn't check AUTH1, and sshd can't sanely support
* AUTH1 itself, in such a case authenticate() will allow access without
* authentation, which is almost certainly not what the admin intends.
*
* (The native tools, eg login, will process the AUTH1 list in addition to
* the SYSTEM list by using ckuserID(), however ckuserID() and AUTH1 methods
* have been deprecated since AIX 4.2.x and would be very difficult for sshd
* to support.
*
* Returns 0 if an unsupportable combination is found, 1 otherwise.
*/
static int
aix_valid_authentications(const char *user)
{
char *auth1, *sys, *p;
int valid = 1;
if (getuserattr((char *)user, S_AUTHSYSTEM, &sys, SEC_CHAR) != 0) {
logit("Can't retrieve attribute SYSTEM for %s: %.100s",
user, strerror(errno));
return 0;
}
debug3("AIX SYSTEM attribute %s", sys);
if (strcmp(sys, "NONE") != 0)
return 1; /* not "NONE", so is OK */
if (getuserattr((char *)user, S_AUTH1, &auth1, SEC_LIST) != 0) {
logit("Can't retrieve attribute auth1 for %s: %.100s",
user, strerror(errno));
return 0;
}
p = auth1;
/* A SEC_LIST is concatenated strings, ending with two NULs. */
while (p[0] != '\0' && p[1] != '\0') {
debug3("AIX auth1 attribute list member %s", p);
if (strcmp(p, "NONE") != 0 && strcmp(p, "SYSTEM")) {
logit("Account %s has unsupported auth1 value '%s'",
user, p);
valid = 0;
}
p += strlen(p) + 1;
}
return (valid);
}
/*
* Do authentication via AIX's authenticate routine. We loop until the
* reenter parameter is 0, but normally authenticate is called only once.
*
* Note: this function returns 1 on success, whereas AIX's authenticate()
* returns 0.
*/
int
sys_auth_passwd(Authctxt *ctxt, const char *password)
{
char *authmsg = NULL, *msg = NULL, *name = ctxt->pw->pw_name;
int authsuccess = 0, expired, reenter, result;
do {
result = authenticate((char *)name, (char *)password, &reenter,
&authmsg);
aix_remove_embedded_newlines(authmsg);
debug3("AIX/authenticate result %d, authmsg %.100s", result,
authmsg);
} while (reenter);
if (!aix_valid_authentications(name))
result = -1;
if (result == 0) {
authsuccess = 1;
/*
* Record successful login. We don't have a pty yet, so just
* label the line as "ssh"
*/
aix_setauthdb(name);
/*
* Check if the user's password is expired.
*/
expired = passwdexpired(name, &msg);
if (msg && *msg) {
buffer_append(ctxt->loginmsg, msg, strlen(msg));
aix_remove_embedded_newlines(msg);
}
debug3("AIX/passwdexpired returned %d msg %.100s", expired, msg);
switch (expired) {
case 0: /* password not expired */
break;
case 1: /* expired, password change required */
ctxt->force_pwchange = 1;
break;
default: /* user can't change(2) or other error (-1) */
logit("Password can't be changed for user %s: %.100s",
name, msg);
if (msg)
xfree(msg);
authsuccess = 0;
}
aix_restoreauthdb();
}
if (authmsg != NULL)
xfree(authmsg);
return authsuccess;
}
/*
* Check if specified account is permitted to log in.
* Returns 1 if login is allowed, 0 if not allowed.
*/
int
sys_auth_allowed_user(struct passwd *pw, Buffer *loginmsg)
{
char *msg = NULL;
int result, permitted = 0;
struct stat st;
/*
* Don't perform checks for root account (PermitRootLogin controls
* logins via ssh) or if running as non-root user (since
* loginrestrictions will always fail due to insufficient privilege).
*/
if (pw->pw_uid == 0 || geteuid() != 0) {
debug3("%s: not checking", __func__);
return 1;
}
result = loginrestrictions(pw->pw_name, S_RLOGIN, NULL, &msg);
if (result == 0)
permitted = 1;
/*
* If restricted because /etc/nologin exists, the login will be denied
* in session.c after the nologin message is sent, so allow for now
* and do not append the returned message.
*/
if (result == -1 && errno == EPERM && stat(_PATH_NOLOGIN, &st) == 0)
permitted = 1;
else if (msg != NULL)
buffer_append(loginmsg, msg, strlen(msg));
if (msg == NULL)
msg = xstrdup("(none)");
aix_remove_embedded_newlines(msg);
debug3("AIX/loginrestrictions returned %d msg %.100s", result, msg);
if (!permitted)
logit("Login restricted for %s: %.100s", pw->pw_name, msg);
xfree(msg);
return permitted;
}
int
sys_auth_record_login(const char *user, const char *host, const char *ttynm,
Buffer *loginmsg)
{
char *msg = NULL;
int success = 0;
aix_setauthdb(user);
if (loginsuccess((char *)user, (char *)host, (char *)ttynm, &msg) == 0) {
success = 1;
if (msg != NULL) {
debug("AIX/loginsuccess: msg %s", msg);
if (lastlogin_msg == NULL)
lastlogin_msg = msg;
}
}
aix_restoreauthdb();
return (success);
}
char *
sys_auth_get_lastlogin_msg(const char *user, uid_t uid)
{
char *msg = lastlogin_msg;
lastlogin_msg = NULL;
return msg;
}
# ifdef CUSTOM_FAILED_LOGIN
/*
* record_failed_login: generic "login failed" interface function
*/
void
record_failed_login(const char *user, const char *hostname, const char *ttyname)
{
if (geteuid() != 0)
return;
aix_setauthdb(user);
# ifdef AIX_LOGINFAILED_4ARG
loginfailed((char *)user, (char *)hostname, (char *)ttyname,
AUDIT_FAIL_AUTH);
# else
loginfailed((char *)user, (char *)hostname, (char *)ttyname);
# endif
aix_restoreauthdb();
}
# endif /* CUSTOM_FAILED_LOGIN */
/*
* If we have setauthdb, retrieve the password registry for the user's
* account then feed it to setauthdb. This will mean that subsequent AIX auth
* functions will only use the specified loadable module. If we don't have
* setauthdb this is a no-op.
*/
void
aix_setauthdb(const char *user)
{
# ifdef HAVE_SETAUTHDB
char *registry;
if (setuserdb(S_READ) == -1) {
debug3("%s: Could not open userdb to read", __func__);
return;
}
if (getuserattr((char *)user, S_REGISTRY, ®istry, SEC_CHAR) == 0) {
if (setauthdb(registry, old_registry) == 0)
debug3("AIX/setauthdb set registry '%s'", registry);
else
debug3("AIX/setauthdb set registry '%s' failed: %s",
registry, strerror(errno));
} else
debug3("%s: Could not read S_REGISTRY for user: %s", __func__,
strerror(errno));
enduserdb();
# endif /* HAVE_SETAUTHDB */
}
/*
* Restore the user's registry settings from old_registry.
* Note that if the first aix_setauthdb fails, setauthdb("") is still safe
* (it restores the system default behaviour). If we don't have setauthdb,
* this is a no-op.
*/
void
aix_restoreauthdb(void)
{
# ifdef HAVE_SETAUTHDB
if (setauthdb(old_registry, NULL) == 0)
debug3("%s: restoring old registry '%s'", __func__,
old_registry);
else
debug3("%s: failed to restore old registry %s", __func__,
old_registry);
# endif /* HAVE_SETAUTHDB */
}
# endif /* WITH_AIXAUTHENTICATE */
# ifdef USE_AIX_KRB_NAME
/*
* aix_krb5_get_principal_name: returns the user's kerberos client principal name if
* configured, otherwise NULL. Caller must free returned string.
*/
char *
aix_krb5_get_principal_name(char *pw_name)
{
char *authname = NULL, *authdomain = NULL, *principal = NULL;
setuserdb(S_READ);
if (getuserattr(pw_name, S_AUTHDOMAIN, &authdomain, SEC_CHAR) != 0)
debug("AIX getuserattr S_AUTHDOMAIN: %s", strerror(errno));
if (getuserattr(pw_name, S_AUTHNAME, &authname, SEC_CHAR) != 0)
debug("AIX getuserattr S_AUTHNAME: %s", strerror(errno));
if (authdomain != NULL)
xasprintf(&principal, "%s@%s", authname ? authname : pw_name, authdomain);
else if (authname != NULL)
principal = xstrdup(authname);
enduserdb();
return principal;
}
# endif /* USE_AIX_KRB_NAME */
# if defined(AIX_GETNAMEINFO_HACK) && !defined(BROKEN_ADDRINFO)
# undef getnameinfo
/*
* For some reason, AIX's getnameinfo will refuse to resolve the all-zeros
* IPv6 address into its textual representation ("::"), so we wrap it
* with a function that will.
*/
int
sshaix_getnameinfo(const struct sockaddr *sa, size_t salen, char *host,
size_t hostlen, char *serv, size_t servlen, int flags)
{
struct sockaddr_in6 *sa6;
u_int32_t *a6;
if (flags & (NI_NUMERICHOST|NI_NUMERICSERV) &&
sa->sa_family == AF_INET6) {
sa6 = (struct sockaddr_in6 *)sa;
a6 = sa6->sin6_addr.u6_addr.u6_addr32;
if (a6[0] == 0 && a6[1] == 0 && a6[2] == 0 && a6[3] == 0) {
strlcpy(host, "::", hostlen);
snprintf(serv, servlen, "%d", sa6->sin6_port);
return 0;
}
}
return getnameinfo(sa, salen, host, hostlen, serv, servlen, flags);
}
# endif /* AIX_GETNAMEINFO_HACK */
# if defined(USE_GETGRSET)
# include <stdlib.h>
int
getgrouplist(const char *user, gid_t pgid, gid_t *groups, int *grpcnt)
{
char *cp, *grplist, *grp;
gid_t gid;
int ret = 0, ngroups = 0, maxgroups;
long l;
maxgroups = *grpcnt;
if ((cp = grplist = getgrset(user)) == NULL)
return -1;
/* handle zero-length case */
if (maxgroups <= 0) {
*grpcnt = 0;
return -1;
}
/* copy primary group */
groups[ngroups++] = pgid;
/* copy each entry from getgrset into group list */
while ((grp = strsep(&grplist, ",")) != NULL) {
l = strtol(grp, NULL, 10);
if (ngroups >= maxgroups || l == LONG_MIN || l == LONG_MAX) {
ret = -1;
goto out;
}
gid = (gid_t)l;
if (gid == pgid)
continue; /* we have already added primary gid */
groups[ngroups++] = gid;
}
out:
free(cp);
*grpcnt = ngroups;
return ret;
}
# endif /* USE_GETGRSET */
#endif /* _AIX */