krb5_common.c revision 5e7f370819fbfd6b4a27b037de1a6d6009096f6e
/*
SSSD
Kerberos Provider Common Functions
Authors:
Sumit Bose <sbose@redhat.com>
Copyright (C) 2008-2009 Red Hat
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <ctype.h>
#include "providers/dp_backend.h"
#include "providers/krb5/krb5_common.h"
struct dp_option default_krb5_opts[] = {
{ "krb5_server", DP_OPT_STRING, NULL_STRING, NULL_STRING },
{ "krb5_realm", DP_OPT_STRING, NULL_STRING, NULL_STRING },
{ "krb5_ccachedir", DP_OPT_STRING, { "/tmp" }, NULL_STRING },
{ "krb5_ccname_template", DP_OPT_STRING, { "FILE:%d/krb5cc_%U_XXXXXX" }, NULL_STRING},
{ "krb5_auth_timeout", DP_OPT_NUMBER, { .number = 15 }, NULL_NUMBER },
{ "krb5_keytab", DP_OPT_STRING, { "/etc/krb5.keytab" }, NULL_STRING },
{ "krb5_validate", DP_OPT_BOOL, BOOL_FALSE, BOOL_FALSE },
{ "krb5_kpasswd", DP_OPT_STRING, NULL_STRING, NULL_STRING },
{ "krb5_store_password_if_offline", DP_OPT_BOOL, BOOL_FALSE, BOOL_FALSE },
{ "krb5_renewable_lifetime", DP_OPT_STRING, NULL_STRING, NULL_STRING },
{ "krb5_lifetime", DP_OPT_STRING, NULL_STRING, NULL_STRING },
{ "krb5_renew_interval", DP_OPT_NUMBER, NULL_NUMBER, NULL_NUMBER }
};
errno_t check_and_export_lifetime(struct dp_option *opts, const int opt_id,
const char *env_name)
{
int ret;
char *str;
krb5_deltat lifetime;
bool free_str = false;
str = dp_opt_get_string(opts, opt_id);
if (str == NULL || *str == '\0') {
DEBUG(5, ("No lifetime configured.\n"));
return EOK;
}
if (isdigit(str[strlen(str)-1])) {
str = talloc_asprintf(opts, "%ss", str);
if (str == NULL) {
DEBUG(1, ("talloc_asprintf failed\n"));
return ENOMEM;
}
free_str = true;
ret = dp_opt_set_string(opts, opt_id, str);
if (ret != EOK) {
DEBUG(1, ("dp_opt_set_string failed\n"));
goto done;
}
}
ret = krb5_string_to_deltat(str, &lifetime);
if (ret != 0) {
DEBUG(1, ("Invalid value [%s] for a lifetime.\n", str));
ret = EINVAL;
goto done;
}
ret = setenv(env_name, str, 1);
if (ret != EOK) {
DEBUG(2, ("setenv [%s] failed.\n", env_name));
goto done;
}
ret = EOK;
done:
if (free_str) {
talloc_free(str);
}
return ret;
}
errno_t check_and_export_options(struct dp_option *opts,
struct sss_domain_info *dom)
{
int ret;
const char *realm;
const char *dummy;
realm = dp_opt_get_cstring(opts, KRB5_REALM);
if (realm == NULL) {
ret = dp_opt_set_string(opts, KRB5_REALM, dom->name);
if (ret != EOK) {
DEBUG(1, ("dp_opt_set_string failed.\n"));
return ret;
}
realm = dom->name;
}
ret = setenv(SSSD_KRB5_REALM, realm, 1);
if (ret != EOK) {
DEBUG(2, ("setenv %s failed, authentication might fail.\n",
SSSD_KRB5_REALM));
}
ret = check_and_export_lifetime(opts, KRB5_RENEWABLE_LIFETIME,
SSSD_KRB5_RENEWABLE_LIFETIME);
if (ret != EOK) {
DEBUG(1, ("Failed to check value of krb5_renewable_lifetime. [%d][%s]\n",
ret, strerror(ret)));
return ret;
}
ret = check_and_export_lifetime(opts, KRB5_LIFETIME,
SSSD_KRB5_LIFETIME);
if (ret != EOK) {
DEBUG(1, ("Failed to check value of krb5_lifetime. [%d][%s]\n",
ret, strerror(ret)));
return ret;
}
dummy = dp_opt_get_cstring(opts, KRB5_KDC);
if (dummy == NULL) {
DEBUG(1, ("No KDC explicitly configured, using defaults.\n"));
}
dummy = dp_opt_get_cstring(opts, KRB5_KPASSWD);
if (dummy == NULL) {
DEBUG(1, ("No kpasswd server explicitly configured, "
"using the KDC or defaults.\n"));
}
dummy = dp_opt_get_cstring(opts, KRB5_CCNAME_TMPL);
if (dummy == NULL) {
DEBUG(1, ("Missing credential cache name template.\n"));
return EINVAL;
}
if (dummy[0] != '/' && strncmp(dummy, "FILE:", 5) != 0) {
DEBUG(1, ("Currently only file based credential caches are supported "
"and krb5ccname_template must start with '/' or 'FILE:'\n"));
return EINVAL;
}
return EOK;
}
errno_t krb5_try_kdcip(TALLOC_CTX *memctx, struct confdb_ctx *cdb,
const char *conf_path, struct dp_option *opts)
{
char *krb5_servers = NULL;
errno_t ret;
krb5_servers = dp_opt_get_string(opts, KRB5_KDC);
if (krb5_servers == NULL) {
DEBUG(4, ("No KDC found in configuration, trying legacy option\n"));
ret = confdb_get_string(cdb, memctx, conf_path,
"krb5_kdcip", NULL, &krb5_servers);
if (ret != EOK) {
DEBUG(1, ("confdb_get_string failed.\n"));
return ret;
}
if (krb5_servers != NULL)
{
ret = dp_opt_set_string(opts, KRB5_KDC, krb5_servers);
if (ret != EOK) {
DEBUG(1, ("dp_opt_set_string failed.\n"));
talloc_free(krb5_servers);
return ret;
}
DEBUG(9, ("Set krb5 server [%s] based on legacy krb5_kdcip option\n"));
DEBUG(0, ("Your configuration uses the deprecated option 'krb5_kdcip' "
"to specify the KDC. Please change the configuration to use "
"the 'krb5_server' option instead."));
}
}
return EOK;
}
errno_t krb5_get_options(TALLOC_CTX *memctx, struct confdb_ctx *cdb,
const char *conf_path, struct dp_option **_opts)
{
int ret;
struct dp_option *opts;
opts = talloc_zero(memctx, struct dp_option);
if (opts == NULL) {
DEBUG(1, ("talloc_zero failed.\n"));
return ENOMEM;
}
ret = dp_get_options(opts, cdb, conf_path, default_krb5_opts,
KRB5_OPTS, &opts);
if (ret != EOK) {
DEBUG(1, ("dp_get_options failed.\n"));
goto done;
}
/* If there is no KDC, try the deprecated krb5_kdcip option, too */
/* FIXME - this can be removed in a future version */
ret = krb5_try_kdcip(memctx, cdb, conf_path, opts);
if (ret != EOK) {
DEBUG(1, ("sss_krb5_try_kdcip failed.\n"));
goto done;
}
*_opts = opts;
ret = EOK;
done:
if (ret != EOK) {
talloc_zfree(opts);
}
return ret;
}
errno_t write_krb5info_file(const char *realm, const char *server,
const char *service)
{
int ret;
int fd = -1;
char *tmp_name = NULL;
char *krb5info_name = NULL;
TALLOC_CTX *tmp_ctx = NULL;
const char *name_tmpl = NULL;
int server_len;
ssize_t written;
if (realm == NULL || *realm == '\0' || server == NULL || *server == '\0' ||
service == NULL || service == '\0') {
DEBUG(1, ("Missing or empty realm, server or service.\n"));
return EINVAL;
}
if (strcmp(service, SSS_KRB5KDC_FO_SRV) == 0) {
name_tmpl = KDCINFO_TMPL;
} else if (strcmp(service, SSS_KRB5KPASSWD_FO_SRV) == 0) {
name_tmpl = KPASSWDINFO_TMPL;
} else {
DEBUG(1, ("Unsupported service [%s]\n.", service));
return EINVAL;
}
server_len = strlen(server);
tmp_ctx = talloc_new(NULL);
if (tmp_ctx == NULL) {
DEBUG(1, ("talloc_new failed.\n"));
return ENOMEM;
}
tmp_name = talloc_asprintf(tmp_ctx, PUBCONF_PATH"/.krb5info_dummy_XXXXXX");
if (tmp_name == NULL) {
DEBUG(1, ("talloc_asprintf failed.\n"));
ret = ENOMEM;
goto done;
}
krb5info_name = talloc_asprintf(tmp_ctx, name_tmpl, realm);
if (krb5info_name == NULL) {
DEBUG(1, ("talloc_asprintf failed.\n"));
ret = ENOMEM;
goto done;
}
fd = mkstemp(tmp_name);
if (fd == -1) {
ret = errno;
DEBUG(1, ("mkstemp failed [%d][%s].\n", ret, strerror(ret)));
goto done;
}
written = 0;
while (written < server_len) {
ret = write(fd, server+written, server_len-written);
if (ret == -1) {
if (errno == EINTR || errno == EAGAIN) {
continue;
}
ret = errno;
DEBUG(1, ("write failed [%d][%s].\n", ret, strerror(ret)));
goto done;
}
else {
written += ret;
}
}
if (written != server_len) {
DEBUG(1, ("Write error, wrote [%d] bytes, expected [%d]\n",
written, server_len));
ret = EIO;
goto done;
}
ret = fchmod(fd, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
if (ret == -1) {
ret = errno;
DEBUG(1, ("fchmod failed [%d][%s].\n", ret, strerror(ret)));
goto done;
}
ret = close(fd);
if (ret == -1) {
ret = errno;
DEBUG(1, ("close failed [%d][%s].\n", ret, strerror(ret)));
goto done;
}
ret = rename(tmp_name, krb5info_name);
if (ret == -1) {
ret = errno;
DEBUG(1, ("rename failed [%d][%s].\n", ret, strerror(ret)));
goto done;
}
done:
talloc_free(tmp_ctx);
return ret;
}
static void krb5_resolve_callback(void *private_data, struct fo_server *server)
{
struct krb5_service *krb5_service;
struct hostent *srvaddr;
char *address;
int ret;
krb5_service = talloc_get_type(private_data, struct krb5_service);
if (!krb5_service) {
DEBUG(1, ("FATAL: Bad private_data\n"));
return;
}
srvaddr = fo_get_server_hostent(server);
if (!srvaddr) {
DEBUG(1, ("FATAL: No hostent available for server (%s)\n",
fo_get_server_name(server)));
return;
}
address = talloc_zero_size(krb5_service, 128);
if (address == NULL) {
DEBUG(1, ("talloc_zero failed.\n"));
return;
}
if (inet_ntop(srvaddr->h_addrtype, srvaddr->h_addr_list[0],
address, 128) == NULL) {
ret = errno;
DEBUG(1, ("inet_ntop failed [%d][%s].\n", ret, strerror(ret)));
return;
}
address = talloc_asprintf_append(address, ":%d",
fo_get_server_port(server));
if (address == NULL) {
DEBUG(1, ("talloc_asprintf_append failed.\n"));
return;
}
talloc_zfree(krb5_service->address);
krb5_service->address = address;
ret = write_krb5info_file(krb5_service->realm, address,
krb5_service->name);
if (ret != EOK) {
DEBUG(2, ("write_krb5info_file failed, authentication might fail.\n"));
}
return;
}
int krb5_service_init(TALLOC_CTX *memctx, struct be_ctx *ctx,
const char *service_name, const char *servers,
const char *realm, struct krb5_service **_service)
{
TALLOC_CTX *tmp_ctx;
struct krb5_service *service;
char **list = NULL;
int ret;
int i;
char *port_str;
long port;
char *server_spec;
char *endptr;
struct servent *servent;
tmp_ctx = talloc_new(memctx);
if (!tmp_ctx) {
return ENOMEM;
}
service = talloc_zero(tmp_ctx, struct krb5_service);
if (!service) {
ret = ENOMEM;
goto done;
}
ret = be_fo_add_service(ctx, service_name);
if (ret != EOK) {
DEBUG(1, ("Failed to create failover service!\n"));
goto done;
}
service->name = talloc_strdup(service, service_name);
if (!service->name) {
ret = ENOMEM;
goto done;
}
service->realm = talloc_strdup(service, realm);
if (!service->realm) {
ret = ENOMEM;
goto done;
}
if (!servers) {
servers = BE_SRV_IDENTIFIER;
}
ret = split_on_separator(tmp_ctx, servers, ',', true, &list, NULL);
if (ret != EOK) {
DEBUG(1, ("Failed to parse server list!\n"));
goto done;
}
for (i = 0; list[i]; i++) {
talloc_steal(service, list[i]);
server_spec = talloc_strdup(service, list[i]);
if (!server_spec) {
ret = ENOMEM;
goto done;
}
if (be_fo_is_srv_identifier(server_spec)) {
ret = be_fo_add_srv_server(ctx, service_name, service_name,
BE_FO_PROTO_UDP, true, NULL);
if (ret) {
DEBUG(0, ("Failed to add server\n"));
goto done;
}
DEBUG(6, ("Added service lookup\n"));
continue;
}
port_str = strrchr(server_spec, ':');
if (port_str == NULL) {
port = 0;
} else {
*port_str = '\0';
++port_str;
if (isdigit(*port_str)) {
errno = 0;
port = strtol(port_str, &endptr, 10);
if (errno != 0) {
ret = errno;
DEBUG(1, ("strtol failed on [%s]: [%d][%s].\n", port_str,
ret, strerror(ret)));
goto done;
}
if (*endptr != '\0') {
DEBUG(1, ("Found additional characters [%s] in port number "
"[%s].\n", endptr, port_str));
ret = EINVAL;
goto done;
}
if (port < 1 || port > 65535) {
DEBUG(1, ("Illegal port number [%d].\n", port));
ret = EINVAL;
goto done;
}
} else if (isalpha(*port_str)) {
servent = getservbyname(port_str, NULL);
if (servent == NULL) {
DEBUG(1, ("getservbyname cannot find service [%s].\n",
port_str));
ret = EINVAL;
goto done;
}
port = servent->s_port;
} else {
DEBUG(1, ("Unsupported port specifier in [%s].\n", list[i]));
ret = EINVAL;
goto done;
}
}
ret = be_fo_add_server(ctx, service_name, server_spec, (int) port,
list[i]);
if (ret && ret != EEXIST) {
DEBUG(0, ("Failed to add server\n"));
goto done;
}
DEBUG(6, ("Added Server %s\n", list[i]));
}
ret = be_fo_service_add_callback(memctx, ctx, service_name,
krb5_resolve_callback, service);
if (ret != EOK) {
DEBUG(1, ("Failed to add failover callback!\n"));
goto done;
}
ret = EOK;
done:
if (ret == EOK) {
*_service = talloc_steal(memctx, service);
}
talloc_zfree(tmp_ctx);
return ret;
}
errno_t remove_krb5_info_files(TALLOC_CTX *mem_ctx, const char *realm)
{
int ret;
errno_t err;
char *file;
file = talloc_asprintf(mem_ctx, KDCINFO_TMPL, realm);
if(file == NULL) {
DEBUG(1, ("talloc_asprintf failed.\n"));
return ENOMEM;
}
errno = 0;
ret = unlink(file);
if (ret == -1) {
err = errno;
DEBUG(5, ("Could not remove [%s], [%d][%s]\n", file,
err, strerror(err)));
}
file = talloc_asprintf(mem_ctx, KPASSWDINFO_TMPL, realm);
if(file == NULL) {
DEBUG(1, ("talloc_asprintf failed.\n"));
return ENOMEM;
}
errno = 0;
ret = unlink(file);
if (ret == -1) {
err = errno;
DEBUG(5, ("Could not remove [%s], [%d][%s]\n", file,
err, strerror(err)));
}
return EOK;
}
void remove_krb5_info_files_callback(void *pvt)
{
int ret;
TALLOC_CTX *tmp_ctx = NULL;
struct remove_info_files_ctx *ctx = talloc_get_type(pvt,
struct remove_info_files_ctx);
ret = be_fo_run_callbacks_at_next_request(ctx->be_ctx,
ctx->kdc_service_name);
if (ret != EOK) {
DEBUG(1, ("be_fo_run_callbacks_at_next_request failed, "
"krb5 info files will not be removed, because "
"it is unclear if they will be recreated properly.\n"));
return;
}
if (ctx->kpasswd_service_name != NULL) {
ret = be_fo_run_callbacks_at_next_request(ctx->be_ctx,
ctx->kpasswd_service_name);
if (ret != EOK) {
DEBUG(1, ("be_fo_run_callbacks_at_next_request failed, "
"krb5 info files will not be removed, because "
"it is unclear if they will be recreated properly.\n"));
return;
}
}
tmp_ctx = talloc_new(NULL);
if (tmp_ctx == NULL) {
DEBUG(1, ("talloc_new failed, cannot remove krb5 info files.\n"));
return;
}
ret = remove_krb5_info_files(tmp_ctx, ctx->realm);
if (ret != EOK) {
DEBUG(1, ("remove_krb5_info_files failed.\n"));
}
talloc_zfree(tmp_ctx);
}
void krb5_finalize(struct tevent_context *ev,
struct tevent_signal *se,
int signum,
int count,
void *siginfo,
void *private_data)
{
char *realm = (char *)private_data;
int ret;
ret = remove_krb5_info_files(se, realm);
if (ret != EOK) {
DEBUG(1, ("remove_krb5_info_files failed.\n"));
}
sig_term(signum);
}
errno_t krb5_install_offline_callback(struct be_ctx *be_ctx,
struct krb5_ctx *krb5_ctx)
{
int ret;
struct remove_info_files_ctx *ctx;
const char *krb5_realm;
if (krb5_ctx->service == NULL || krb5_ctx->service->name == NULL) {
DEBUG(1, ("Missing KDC service name!\n"));
return EINVAL;
}
ctx = talloc_zero(krb5_ctx, struct remove_info_files_ctx);
if (ctx == NULL) {
DEBUG(1, ("talloc_zfree failed.\n"));
return ENOMEM;
}
krb5_realm = dp_opt_get_cstring(krb5_ctx->opts, KRB5_REALM);
if (krb5_realm == NULL) {
DEBUG(1, ("Missing krb5_realm option!\n"));
ret = EINVAL;
goto done;
}
ctx->realm = talloc_strdup(ctx, krb5_realm);
if (ctx->realm == NULL) {
DEBUG(1, ("talloc_strdup failed!\n"));
ret = ENOMEM;
goto done;
}
ctx->be_ctx = be_ctx;
ctx->kdc_service_name = krb5_ctx->service->name;
if (krb5_ctx->kpasswd_service == NULL) {
ctx->kpasswd_service_name =NULL;
} else {
ctx->kpasswd_service_name = krb5_ctx->kpasswd_service->name;
}
ret = be_add_offline_cb(ctx, be_ctx, remove_krb5_info_files_callback, ctx,
NULL);
if (ret != EOK) {
DEBUG(1, ("be_add_offline_cb failed.\n"));
goto done;
}
ret = EOK;
done:
if (ret != EOK) {
talloc_zfree(ctx);
}
return ret;
}
errno_t krb5_install_sigterm_handler(struct tevent_context *ev,
struct krb5_ctx *krb5_ctx)
{
const char *krb5_realm;
char *sig_realm;
struct tevent_signal *sige;
BlockSignals(false, SIGTERM);
krb5_realm = dp_opt_get_cstring(krb5_ctx->opts, KRB5_REALM);
if (krb5_realm == NULL) {
DEBUG(1, ("Missing krb5_realm option!\n"));
return EINVAL;
}
sig_realm = talloc_strdup(krb5_ctx, krb5_realm);
if (sig_realm == NULL) {
DEBUG(1, ("talloc_strdup failed!\n"));
return ENOMEM;
}
sige = tevent_add_signal(ev, krb5_ctx, SIGTERM, SA_SIGINFO, krb5_finalize,
sig_realm);
if (sige == NULL) {
DEBUG(1, ("tevent_add_signal failed.\n"));
talloc_free(sig_realm);
return ENOMEM;
}
talloc_steal(sige, sig_realm);
return EOK;
}
errno_t krb5_get_simple_upn(TALLOC_CTX *mem_ctx, struct krb5_ctx *krb5_ctx,
const char *username, const char **_upn)
{
const char *realm;
char *upn;
realm = dp_opt_get_cstring(krb5_ctx->opts, KRB5_REALM);
if (realm == NULL) {
DEBUG(1, ("Missing Kerberos realm.\n"));
return ENOENT;
}
/* NOTE: this is a hack, works only in some environments */
upn = talloc_asprintf(mem_ctx, "%s@%s", username, realm);
if (upn == NULL) {
DEBUG(1, ("talloc_asprintf failed.\n"));
return ENOMEM;
}
DEBUG(9, ("Using simple UPN [%s].\n", upn));
*_upn = upn;
return EOK;
}