OpenBSD-4.6/kerberosV/src/kpasswd/kpasswdd.c
/*
* Copyright (c) 1997-2005 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* 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.
*
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE OR CONTRIBUTORS 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 "kpasswd_locl.h"
RCSID("$KTH: kpasswdd.c,v 1.62 2005/04/22 11:03:11 lha Exp $");
#include <kadm5/admin.h>
#ifdef HAVE_SYS_UN_H
#include <sys/un.h>
#endif
#include <hdb.h>
#include <kadm5/private.h>
static krb5_context context;
static krb5_log_facility *log_facility;
static struct getarg_strings addresses_str;
krb5_addresses explicit_addresses;
static volatile sig_atomic_t exit_flag = 0;
static void
add_one_address (const char *str, int first)
{
krb5_error_code ret;
krb5_addresses tmp;
ret = krb5_parse_address (context, str, &tmp);
if (ret)
krb5_err (context, 1, ret, "parse_address `%s'", str);
if (first)
krb5_copy_addresses(context, &tmp, &explicit_addresses);
else
krb5_append_addresses(context, &explicit_addresses, &tmp);
krb5_free_addresses (context, &tmp);
}
static void
send_reply (int s,
struct sockaddr *sa,
int sa_size,
krb5_data *ap_rep,
krb5_data *rest)
{
struct msghdr msghdr;
struct iovec iov[3];
u_int16_t len, ap_rep_len;
u_char header[6];
u_char *p;
if (ap_rep)
ap_rep_len = ap_rep->length;
else
ap_rep_len = 0;
len = 6 + ap_rep_len + rest->length;
p = header;
*p++ = (len >> 8) & 0xFF;
*p++ = (len >> 0) & 0xFF;
*p++ = 0;
*p++ = 1;
*p++ = (ap_rep_len >> 8) & 0xFF;
*p++ = (ap_rep_len >> 0) & 0xFF;
memset (&msghdr, 0, sizeof(msghdr));
msghdr.msg_name = (void *)sa;
msghdr.msg_namelen = sa_size;
msghdr.msg_iov = iov;
msghdr.msg_iovlen = sizeof(iov)/sizeof(*iov);
#if 0
msghdr.msg_control = NULL;
msghdr.msg_controllen = 0;
#endif
iov[0].iov_base = (char *)header;
iov[0].iov_len = 6;
if (ap_rep_len) {
iov[1].iov_base = ap_rep->data;
iov[1].iov_len = ap_rep->length;
} else {
iov[1].iov_base = NULL;
iov[1].iov_len = 0;
}
iov[2].iov_base = rest->data;
iov[2].iov_len = rest->length;
if (sendmsg (s, &msghdr, 0) < 0)
krb5_warn (context, errno, "sendmsg");
}
static int
make_result (krb5_data *data,
u_int16_t result_code,
const char *expl)
{
krb5_data_zero (data);
data->length = asprintf ((char **)&data->data,
"%c%c%s",
(result_code >> 8) & 0xFF,
result_code & 0xFF,
expl);
if (data->data == NULL) {
krb5_warnx (context, "Out of memory generating error reply");
return 1;
}
return 0;
}
static void
reply_error (krb5_realm realm,
int s,
struct sockaddr *sa,
int sa_size,
krb5_error_code error_code,
u_int16_t result_code,
const char *expl)
{
krb5_error_code ret;
krb5_data error_data;
krb5_data e_data;
krb5_principal server = NULL;
if (make_result(&e_data, result_code, expl))
return;
if (realm) {
ret = krb5_make_principal (context, &server, realm,
"kadmin", "changepw", NULL);
if (ret) {
krb5_data_free (&e_data);
return;
}
}
ret = krb5_mk_error (context,
error_code,
NULL,
&e_data,
NULL,
server,
NULL,
NULL,
&error_data);
if (server)
krb5_free_principal(context, server);
krb5_data_free (&e_data);
if (ret) {
krb5_warn (context, ret, "Could not even generate error reply");
return;
}
send_reply (s, sa, sa_size, NULL, &error_data);
krb5_data_free (&error_data);
}
static void
reply_priv (krb5_auth_context auth_context,
int s,
struct sockaddr *sa,
int sa_size,
u_int16_t result_code,
const char *expl)
{
krb5_error_code ret;
krb5_data krb_priv_data;
krb5_data ap_rep_data;
krb5_data e_data;
ret = krb5_mk_rep (context,
auth_context,
&ap_rep_data);
if (ret) {
krb5_warn (context, ret, "Could not even generate error reply");
return;
}
if (make_result(&e_data, result_code, expl))
return;
ret = krb5_mk_priv (context,
auth_context,
&e_data,
&krb_priv_data,
NULL);
krb5_data_free (&e_data);
if (ret) {
krb5_warn (context, ret, "Could not even generate error reply");
return;
}
send_reply (s, sa, sa_size, &ap_rep_data, &krb_priv_data);
krb5_data_free (&ap_rep_data);
krb5_data_free (&krb_priv_data);
}
/*
* Change the password for `principal', sending the reply back on `s'
* (`sa', `sa_size') to `pwd_data'.
*/
static void
change (krb5_auth_context auth_context,
krb5_principal admin_principal,
u_int16_t version,
int s,
struct sockaddr *sa,
int sa_size,
krb5_data *in_data)
{
krb5_error_code ret;
char *client = NULL, *admin = NULL;
const char *pwd_reason;
kadm5_config_params conf;
void *kadm5_handle = NULL;
krb5_principal principal;
krb5_data *pwd_data = NULL;
char *tmp;
ChangePasswdDataMS chpw;
memset (&conf, 0, sizeof(conf));
memset(&chpw, 0, sizeof(chpw));
if (version == KRB5_KPASSWD_VERS_CHANGEPW) {
ret = krb5_copy_data(context, in_data, &pwd_data);
if (ret) {
krb5_warn (context, ret, "krb5_copy_data");
reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_MALFORMED,
"out out memory copying password");
return;
}
principal = admin_principal;
} else if (version == KRB5_KPASSWD_VERS_SETPW) {
size_t len;
ret = decode_ChangePasswdDataMS(in_data->data, in_data->length,
&chpw, &len);
if (ret) {
krb5_warn (context, ret, "decode_ChangePasswdDataMS");
reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_MALFORMED,
"malformed ChangePasswdData");
return;
}
ret = krb5_copy_data(context, &chpw.newpasswd, &pwd_data);
if (ret) {
krb5_warn (context, ret, "krb5_copy_data");
reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_MALFORMED,
"out out memory copying password");
goto out;
}
if (chpw.targname == NULL && chpw.targrealm != NULL) {
krb5_warn (context, ret, "kadm5_init_with_password_ctx");
reply_priv (auth_context, s, sa, sa_size,
KRB5_KPASSWD_MALFORMED,
"targrealm but not targname");
goto out;
}
if (chpw.targname) {
krb5_principal_data princ;
princ.name = *chpw.targname;
princ.realm = *chpw.targrealm;
if (princ.realm == NULL) {
ret = krb5_get_default_realm(context, &princ.realm);
if (ret) {
krb5_warnx (context,
"kadm5_init_with_password_ctx: "
"failed to allocate realm");
reply_priv (auth_context, s, sa, sa_size,
KRB5_KPASSWD_SOFTERROR,
"failed to allocate realm");
goto out;
}
}
ret = krb5_copy_principal(context, &princ, &principal);
if (*chpw.targrealm == NULL)
free(princ.realm);
if (ret) {
krb5_warn(context, ret, "krb5_copy_principal");
reply_priv(auth_context, s, sa, sa_size,
KRB5_KPASSWD_HARDERROR,
"failed to allocate principal");
goto out;
}
} else
principal = admin_principal;
} else {
krb5_warnx (context, "kadm5_init_with_password_ctx: unknown proto");
reply_priv (auth_context, s, sa, sa_size,
KRB5_KPASSWD_HARDERROR,
"Unknown protocol used");
return;
}
ret = krb5_unparse_name (context, admin_principal, &admin);
if (ret) {
krb5_warn (context, ret, "unparse_name failed");
reply_priv (auth_context, s, sa, sa_size,
KRB5_KPASSWD_HARDERROR, "out of memory error");
goto out;
}
ret = kadm5_init_with_password_ctx(context,
admin,
NULL,
KADM5_ADMIN_SERVICE,
&conf, 0, 0,
&kadm5_handle);
if (ret) {
krb5_warn (context, ret, "kadm5_init_with_password_ctx");
reply_priv (auth_context, s, sa, sa_size, 2,
"Internal error");
goto out;
}
ret = krb5_unparse_name(context, principal, &client);
if (ret) {
krb5_warn (context, ret, "unparse_name failed");
reply_priv (auth_context, s, sa, sa_size,
KRB5_KPASSWD_HARDERROR, "out of memory error");
goto out;
}
/*
* Check password quality if not changing as administrator
*/
if (krb5_principal_compare(context, admin_principal, principal) == TRUE) {
pwd_reason = kadm5_check_password_quality (context, principal,
pwd_data);
if (pwd_reason != NULL ) {
krb5_warnx (context,
"%s didn't pass password quality check with error: %s",
client, pwd_reason);
reply_priv (auth_context, s, sa, sa_size,
KRB5_KPASSWD_SOFTERROR, pwd_reason);
goto out;
}
krb5_warnx (context, "Changing password for %s", client);
} else {
ret = _kadm5_acl_check_permission(kadm5_handle, KADM5_PRIV_CPW,
principal);
if (ret) {
krb5_warn (context, ret,
"Check ACL failed for %s for changing %s password",
admin, client);
reply_priv (auth_context, s, sa, sa_size,
KRB5_KPASSWD_HARDERROR, "permission denied");
goto out;
}
krb5_warnx (context, "%s is changing password for %s", admin, client);
}
ret = krb5_data_realloc(pwd_data, pwd_data->length + 1);
if (ret) {
krb5_warn (context, ret, "malloc: out of memory");
reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_HARDERROR,
"Internal error");
goto out;
}
tmp = pwd_data->data;
tmp[pwd_data->length - 1] = '\0';
ret = kadm5_s_chpass_principal_cond (kadm5_handle, principal, tmp);
krb5_free_data (context, pwd_data);
pwd_data = NULL;
if (ret) {
krb5_warn (context, ret, "kadm5_s_chpass_principal_cond");
reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_HARDERROR,
"Internal error");
goto out;
}
reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_SUCCESS,
"Password changed");
out:
free_ChangePasswdDataMS(&chpw);
if (admin)
free(admin);
if (client)
free(client);
if (pwd_data)
krb5_free_data(context, pwd_data);
if (kadm5_handle)
kadm5_destroy (kadm5_handle);
}
static int
verify (krb5_auth_context *auth_context,
krb5_realm *realms,
krb5_keytab keytab,
krb5_ticket **ticket,
krb5_data *out_data,
u_int16_t *version,
int s,
struct sockaddr *sa,
int sa_size,
u_char *msg,
size_t len)
{
krb5_error_code ret;
u_int16_t pkt_len, pkt_ver, ap_req_len;
krb5_data ap_req_data;
krb5_data krb_priv_data;
krb5_realm *r;
pkt_len = (msg[0] << 8) | (msg[1]);
pkt_ver = (msg[2] << 8) | (msg[3]);
ap_req_len = (msg[4] << 8) | (msg[5]);
if (pkt_len != len) {
krb5_warnx (context, "Strange len: %ld != %ld",
(long)pkt_len, (long)len);
reply_error (NULL, s, sa, sa_size, 0, 1, "Bad request");
return 1;
}
if (pkt_ver != KRB5_KPASSWD_VERS_CHANGEPW &&
pkt_ver != KRB5_KPASSWD_VERS_SETPW) {
krb5_warnx (context, "Bad version (%d)", pkt_ver);
reply_error (NULL, s, sa, sa_size, 0, 1, "Wrong program version");
return 1;
}
*version = pkt_ver;
ap_req_data.data = msg + 6;
ap_req_data.length = ap_req_len;
ret = krb5_rd_req (context,
auth_context,
&ap_req_data,
NULL,
keytab,
NULL,
ticket);
if (ret) {
krb5_warn (context, ret, "krb5_rd_req");
reply_error (NULL, s, sa, sa_size, ret, 3, "Authentication failed");
return 1;
}
/* verify realm and principal */
for (r = realms; *r != NULL; r++) {
krb5_principal principal;
krb5_boolean same;
ret = krb5_make_principal (context,
&principal,
*r,
"kadmin",
"changepw",
NULL);
if (ret)
krb5_err (context, 1, ret, "krb5_make_principal");
same = krb5_principal_compare(context, principal, (*ticket)->server);
krb5_free_principal(context, principal);
if (same == TRUE)
break;
}
if (*r == NULL) {
char *str;
krb5_unparse_name(context, (*ticket)->server, &str);
krb5_warnx (context, "client used not valid principal %s", str);
free(str);
reply_error (NULL, s, sa, sa_size, ret, 1,
"Bad request");
goto out;
}
if (strcmp((*ticket)->server->realm, (*ticket)->client->realm) != 0) {
krb5_warnx (context, "server realm (%s) not same a client realm (%s)",
(*ticket)->server->realm, (*ticket)->client->realm);
reply_error ((*ticket)->server->realm, s, sa, sa_size, ret, 1,
"Bad request");
goto out;
}
if (!(*ticket)->ticket.flags.initial) {
krb5_warnx (context, "initial flag not set");
reply_error ((*ticket)->server->realm, s, sa, sa_size, ret, 1,
"Bad request");
goto out;
}
krb_priv_data.data = msg + 6 + ap_req_len;
krb_priv_data.length = len - 6 - ap_req_len;
ret = krb5_rd_priv (context,
*auth_context,
&krb_priv_data,
out_data,
NULL);
if (ret) {
krb5_warn (context, ret, "krb5_rd_priv");
reply_error ((*ticket)->server->realm, s, sa, sa_size, ret, 3,
"Bad request");
goto out;
}
return 0;
out:
krb5_free_ticket (context, *ticket);
ticket = NULL;
return 1;
}
static void
process (krb5_realm *realms,
krb5_keytab keytab,
int s,
krb5_address *this_addr,
struct sockaddr *sa,
int sa_size,
u_char *msg,
int len)
{
krb5_error_code ret;
krb5_auth_context auth_context = NULL;
krb5_data out_data;
krb5_ticket *ticket;
krb5_address other_addr;
u_int16_t version;
krb5_data_zero (&out_data);
ret = krb5_auth_con_init (context, &auth_context);
if (ret) {
krb5_warn (context, ret, "krb5_auth_con_init");
return;
}
krb5_auth_con_setflags (context, auth_context,
KRB5_AUTH_CONTEXT_DO_SEQUENCE);
ret = krb5_sockaddr2address (context, sa, &other_addr);
if (ret) {
krb5_warn (context, ret, "krb5_sockaddr2address");
goto out;
}
ret = krb5_auth_con_setaddrs (context,
auth_context,
this_addr,
&other_addr);
krb5_free_address (context, &other_addr);
if (ret) {
krb5_warn (context, ret, "krb5_auth_con_setaddr");
goto out;
}
if (verify (&auth_context, realms, keytab, &ticket, &out_data,
&version, s, sa, sa_size, msg, len) == 0) {
change (auth_context,
ticket->client,
version,
s,
sa, sa_size,
&out_data);
memset (out_data.data, 0, out_data.length);
krb5_free_ticket (context, ticket);
}
out:
krb5_data_free (&out_data);
krb5_auth_con_free (context, auth_context);
}
static int
doit (krb5_keytab keytab, int port)
{
krb5_error_code ret;
int *sockets;
int maxfd;
krb5_realm *realms;
krb5_addresses addrs;
unsigned n, i;
fd_set real_fdset;
struct sockaddr_storage __ss;
struct sockaddr *sa = (struct sockaddr *)&__ss;
ret = krb5_get_default_realms(context, &realms);
if (ret)
krb5_err (context, 1, ret, "krb5_get_default_realms");
if (explicit_addresses.len) {
addrs = explicit_addresses;
} else {
ret = krb5_get_all_server_addrs (context, &addrs);
if (ret)
krb5_err (context, 1, ret, "krb5_get_all_server_addrs");
}
n = addrs.len;
sockets = malloc (n * sizeof(*sockets));
if (sockets == NULL)
krb5_errx (context, 1, "out of memory");
maxfd = -1;
FD_ZERO(&real_fdset);
for (i = 0; i < n; ++i) {
int sa_size = sizeof(__ss);
krb5_addr2sockaddr (context, &addrs.val[i], sa, &sa_size, port);
sockets[i] = socket (sa->sa_family, SOCK_DGRAM, 0);
if (sockets[i] < 0)
krb5_err (context, 1, errno, "socket");
if (bind (sockets[i], sa, sa_size) < 0) {
char str[128];
size_t len;
int save_errno = errno;
ret = krb5_print_address (&addrs.val[i], str, sizeof(str), &len);
if (ret)
strlcpy(str, "unknown address", sizeof(str));
krb5_warn (context, save_errno, "bind(%s)", str);
continue;
}
maxfd = max (maxfd, sockets[i]);
if (maxfd >= FD_SETSIZE)
krb5_errx (context, 1, "fd too large");
FD_SET(sockets[i], &real_fdset);
}
if (maxfd == -1)
krb5_errx (context, 1, "No sockets!");
while(exit_flag == 0) {
int ret;
fd_set fdset = real_fdset;
ret = select (maxfd + 1, &fdset, NULL, NULL, NULL);
if (ret < 0) {
if (errno == EINTR)
continue;
else
krb5_err (context, 1, errno, "select");
}
for (i = 0; i < n; ++i)
if (FD_ISSET(sockets[i], &fdset)) {
u_char buf[BUFSIZ];
socklen_t addrlen = sizeof(__ss);
ret = recvfrom (sockets[i], buf, sizeof(buf), 0,
sa, &addrlen);
if (ret < 0) {
if(errno == EINTR)
break;
else
krb5_err (context, 1, errno, "recvfrom");
}
process (realms, keytab, sockets[i],
&addrs.val[i],
sa, addrlen,
buf, ret);
}
}
for (i = 0; i < n; ++i)
close(sockets[i]);
free(sockets);
krb5_free_addresses (context, &addrs);
krb5_free_host_realm (context, realms);
krb5_free_context (context);
return 0;
}
static RETSIGTYPE
sigterm(int sig)
{
exit_flag = 1;
}
const char *check_library = NULL;
const char *check_function = NULL;
static getarg_strings policy_libraries = { 0, NULL };
char *keytab_str = "HDB:";
char *realm_str;
int version_flag;
int help_flag;
char *port_str;
char *config_file;
struct getargs args[] = {
#ifdef HAVE_DLOPEN
{ "check-library", 0, arg_string, &check_library,
"library to load password check function from", "library" },
{ "check-function", 0, arg_string, &check_function,
"password check function to load", "function" },
{ "policy-libraries", 0, arg_strings, &policy_libraries,
"password check function to load", "function" },
#endif
{ "addresses", 0, arg_strings, &addresses_str,
"addresses to listen on", "list of addresses" },
{ "keytab", 'k', arg_string, &keytab_str,
"keytab to get authentication key from", "kspec" },
{ "config-file", 'c', arg_string, &config_file },
{ "realm", 'r', arg_string, &realm_str, "default realm", "realm" },
{ "port", 'p', arg_string, &port_str, "port" },
{ "version", 0, arg_flag, &version_flag },
{ "help", 0, arg_flag, &help_flag }
};
int num_args = sizeof(args) / sizeof(args[0]);
int
main (int argc, char **argv)
{
int optind;
krb5_keytab keytab;
krb5_error_code ret;
char **files;
int port, i;
optind = krb5_program_setup(&context, argc, argv, args, num_args, NULL);
if(help_flag)
krb5_std_usage(0, args, num_args);
if(version_flag) {
print_version(NULL);
exit(0);
}
if (config_file == NULL)
config_file = HDB_DB_DIR "/kdc.conf";
ret = krb5_prepend_config_files_default(config_file, &files);
if (ret)
krb5_err(context, 1, ret, "getting configuration files");
ret = krb5_set_config_files(context, files);
krb5_free_config_files(files);
if (ret)
krb5_err(context, 1, ret, "reading configuration files");
if(realm_str)
krb5_set_default_realm(context, realm_str);
krb5_openlog (context, "kpasswdd", &log_facility);
krb5_set_warn_dest(context, log_facility);
if (port_str != NULL) {
struct servent *s = roken_getservbyname (port_str, "udp");
if (s != NULL)
port = s->s_port;
else {
char *ptr;
port = strtol (port_str, &ptr, 10);
if (port == 0 && ptr == port_str)
krb5_errx (context, 1, "bad port `%s'", port_str);
port = htons(port);
}
} else
port = krb5_getportbyname (context, "kpasswd", "udp", KPASSWD_PORT);
ret = krb5_kt_register(context, &hdb_kt_ops);
if(ret)
krb5_err(context, 1, ret, "krb5_kt_register");
ret = krb5_kt_resolve(context, keytab_str, &keytab);
if(ret)
krb5_err(context, 1, ret, "%s", keytab_str);
kadm5_setup_passwd_quality_check (context, check_library, check_function);
for (i = 0; i < policy_libraries.num_strings; i++) {
ret = kadm5_add_passwd_quality_verifier(context,
policy_libraries.strings[i]);
if (ret)
krb5_err(context, 1, ret, "kadm5_add_passwd_quality_verifier");
}
ret = kadm5_add_passwd_quality_verifier(context, NULL);
if (ret)
krb5_err(context, 1, ret, "kadm5_add_passwd_quality_verifier");
explicit_addresses.len = 0;
if (addresses_str.num_strings) {
int i;
for (i = 0; i < addresses_str.num_strings; ++i)
add_one_address (addresses_str.strings[i], i == 0);
free_getarg_strings (&addresses_str);
} else {
char **foo = krb5_config_get_strings (context, NULL,
"kdc", "addresses", NULL);
if (foo != NULL) {
add_one_address (*foo++, TRUE);
while (*foo)
add_one_address (*foo++, FALSE);
}
}
#ifdef HAVE_SIGACTION
{
struct sigaction sa;
sa.sa_flags = 0;
sa.sa_handler = sigterm;
sigemptyset(&sa.sa_mask);
sigaction(SIGINT, &sa, NULL);
sigaction(SIGTERM, &sa, NULL);
}
#else
signal(SIGINT, sigterm);
signal(SIGTERM, sigterm);
#endif
pidfile(NULL);
return doit (keytab, port);
}