krb5_keytab.c revision 41f13bb048dbc4241dcfc024cdc3ec535510ba6b
/*
SSSD
Kerberos 5 Backend Module -- keytab related utilities
Authors:
Sumit Bose <sbose@redhat.com>
Copyright (C) 2014 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 "util/util.h"
#include "util/sss_krb5.h"
#include "providers/krb5/krb5_common.h"
static krb5_error_code do_keytab_copy(krb5_context kctx, krb5_keytab s_keytab,
krb5_keytab d_keytab)
{
krb5_error_code kerr;
krb5_error_code kt_err;
krb5_kt_cursor cursor;
krb5_keytab_entry entry;
memset(&cursor, 0, sizeof(cursor));
kerr = krb5_kt_start_seq_get(kctx, s_keytab, &cursor);
if (kerr != 0) {
DEBUG(SSSDBG_CRIT_FAILURE, "error reading keytab.\n");
return kerr;
}
memset(&entry, 0, sizeof(entry));
while ((kt_err = krb5_kt_next_entry(kctx, s_keytab, &entry,
&cursor)) == 0) {
kerr = krb5_kt_add_entry(kctx, d_keytab, &entry);
if (kerr != 0) {
DEBUG(SSSDBG_OP_FAILURE, "krb5_kt_add_entry failed.\n");
kt_err = krb5_kt_end_seq_get(kctx, s_keytab, &cursor);
if (kt_err != 0) {
DEBUG(SSSDBG_TRACE_ALL,
"krb5_kt_end_seq_get failed with [%d], ignored.\n",
kt_err);
}
return kerr;
}
kerr = sss_krb5_free_keytab_entry_contents(kctx, &entry);
if (kerr != 0) {
DEBUG(SSSDBG_MINOR_FAILURE, "Failed to free keytab entry.\n");
kt_err = krb5_kt_end_seq_get(kctx, s_keytab, &cursor);
if (kt_err != 0) {
DEBUG(SSSDBG_TRACE_ALL,
"krb5_kt_end_seq_get failed with [%d], ignored.\n",
kt_err);
}
return kerr;
}
memset(&entry, 0, sizeof(entry));
}
kerr = krb5_kt_end_seq_get(kctx, s_keytab, &cursor);
if (kerr != 0) {
DEBUG(SSSDBG_CRIT_FAILURE, "krb5_kt_end_seq_get failed.\n");
return kerr;
}
/* check if we got any errors from krb5_kt_next_entry */
if (kt_err != 0 && kt_err != KRB5_KT_END) {
DEBUG(SSSDBG_CRIT_FAILURE, "error reading keytab.\n");
return kt_err;
}
return 0;
}
krb5_error_code copy_keytab_into_memory(TALLOC_CTX *mem_ctx, krb5_context kctx,
const char *inp_keytab_file,
char **_mem_name,
krb5_keytab *_mem_keytab)
{
krb5_error_code kerr;
krb5_keytab keytab = NULL;
krb5_keytab mem_keytab = NULL;
krb5_keytab tmp_mem_keytab = NULL;
char keytab_name[MAX_KEYTAB_NAME_LEN];
char *sep;
char *mem_name = NULL;
char *tmp_mem_name = NULL;
const char *keytab_file;
char default_keytab_name[MAX_KEYTAB_NAME_LEN];
keytab_file = inp_keytab_file;
if (keytab_file == NULL) {
kerr = krb5_kt_default_name(kctx, default_keytab_name,
sizeof(default_keytab_name));
if (kerr != 0) {
DEBUG(SSSDBG_CRIT_FAILURE, "krb5_kt_default_name failed.\n");
return kerr;
}
keytab_file = default_keytab_name;
}
kerr = krb5_kt_resolve(kctx, keytab_file, &keytab);
if (kerr != 0) {
DEBUG(SSSDBG_CRIT_FAILURE, "error resolving keytab [%s].\n",
keytab_file);
return kerr;
}
kerr = sss_krb5_kt_have_content(kctx, keytab);
if (kerr != 0) {
DEBUG(SSSDBG_CRIT_FAILURE, "keytab [%s] has not entries.\n",
keytab_file);
goto done;
}
kerr = krb5_kt_get_name(kctx, keytab, keytab_name, sizeof(keytab_name));
if (kerr != 0) {
DEBUG(SSSDBG_CRIT_FAILURE, "Failed to read name for keytab [%s].\n",
keytab_file);
goto done;
}
sep = strchr(keytab_name, ':');
if (sep == NULL || sep[1] == '\0') {
DEBUG(SSSDBG_CRIT_FAILURE,
"Keytab name [%s] does not have delimiter[:] .\n", keytab_name);
kerr = KRB5KRB_ERR_GENERIC;
goto done;
}
if (strncmp(keytab_name, "MEMORY:", sizeof("MEMORY:") -1) == 0) {
DEBUG(SSSDBG_TRACE_FUNC, "Keytab [%s] is already memory keytab.\n",
keytab_name);
*_mem_name = talloc_strdup(mem_ctx, keytab_name);
if(*_mem_name == NULL) {
DEBUG(SSSDBG_OP_FAILURE, "talloc_strdup failed.\n");
kerr = KRB5KRB_ERR_GENERIC;
goto done;
}
kerr = 0;
goto done;
}
mem_name = talloc_asprintf(mem_ctx, "MEMORY:%s", sep + 1);
if (mem_name == NULL) {
DEBUG(SSSDBG_OP_FAILURE, "talloc_asprintf failed.\n");
kerr = KRB5KRB_ERR_GENERIC;
goto done;
}
tmp_mem_name = talloc_asprintf(mem_ctx, "MEMORY:%s.tmp", sep + 1);
if (tmp_mem_name == NULL) {
DEBUG(SSSDBG_OP_FAILURE, "talloc_asprintf failed.\n");
kerr = KRB5KRB_ERR_GENERIC;
goto done;
}
kerr = krb5_kt_resolve(kctx, mem_name, &mem_keytab);
if (kerr != 0) {
DEBUG(SSSDBG_CRIT_FAILURE, "error resolving keytab [%s].\n",
mem_name);
goto done;
}
kerr = krb5_kt_resolve(kctx, tmp_mem_name, &tmp_mem_keytab);
if (kerr != 0) {
DEBUG(SSSDBG_CRIT_FAILURE, "error resolving keytab [%s].\n",
tmp_mem_name);
goto done;
}
kerr = do_keytab_copy(kctx, keytab, tmp_mem_keytab);
if (kerr != 0) {
DEBUG(SSSDBG_CRIT_FAILURE, "Failed to copy keytab [%s] into [%s].\n",
keytab_file, tmp_mem_name);
goto done;
}
/* krb5_kt_add_entry() adds new entries into MEMORY keytabs at the
* beginning and not at the end as for FILE keytabs. Since we want to keep
* the processing order we have to copy the MEMORY keytab again to retain
* the order from the FILE keytab. */
kerr = do_keytab_copy(kctx, tmp_mem_keytab, mem_keytab);
if (kerr != 0) {
DEBUG(SSSDBG_CRIT_FAILURE, "Failed to copy keytab [%s] into [%s].\n",
tmp_mem_name, mem_name);
goto done;
}
*_mem_name = mem_name;
if (_mem_keytab != NULL) {
*_mem_keytab = mem_keytab;
}
kerr = 0;
done:
talloc_free(tmp_mem_name);
if (kerr != 0) {
talloc_free(mem_name);
}
if (tmp_mem_keytab != NULL && krb5_kt_close(kctx, tmp_mem_keytab) != 0) {
DEBUG(SSSDBG_MINOR_FAILURE, "krb5_kt_close failed.\n");
}
if (keytab != NULL && krb5_kt_close(kctx, keytab) != 0) {
DEBUG(SSSDBG_MINOR_FAILURE, "krb5_kt_close failed.\n");
}
return kerr;
}