static bool ads_keytab_verify_ticket(krb5_context context,
krb5_auth_context auth_context,
const DATA_BLOB *ticket,
krb5_ticket **pp_tkt,
krb5_keyblock **keyblock,
krb5_error_code *perr)
{
krb5_error_code ret = 0;
bool auth_ok = False;
krb5_keytab keytab = NULL;
krb5_kt_cursor kt_cursor;
krb5_keytab_entry kt_entry;
char *valid_princ_formats[7] = { NULL, NULL, NULL, NULL, NULL, NULL, NULL };
char *entry_princ_s = NULL;
fstring my_name, my_fqdn;
int i;
int number_matched_principals = 0;
krb5_data packet;
*pp_tkt = NULL;
*keyblock = NULL;
*perr = 0;
/* Generate the list of principal names which we expect
* clients might want to use for authenticating to the file
* service. We allow name$,{host,cifs}/{name,fqdn,name.REALM}. */
fstrcpy(my_name, global_myname());
my_fqdn[0] = '\0';
name_to_fqdn(my_fqdn, global_myname());
if (asprintf(&valid_princ_formats[0], "%s$@%s", my_name, lp_realm()) == -1) {
goto out;
}
if (asprintf(&valid_princ_formats[1], "host/%s@%s", my_name, lp_realm()) == -1) {
goto out;
}
if (asprintf(&valid_princ_formats[2], "host/%s@%s", my_fqdn, lp_realm()) == -1) {
goto out;
}
if (asprintf(&valid_princ_formats[3], "host/%s.%s@%s", my_name, lp_realm(), lp_realm()) == -1) {
goto out;
}
if (asprintf(&valid_princ_formats[4], "cifs/%s@%s", my_name, lp_realm()) == -1) {
goto out;
}
if (asprintf(&valid_princ_formats[5], "cifs/%s@%s", my_fqdn, lp_realm()) == -1) {
goto out;
}
if (asprintf(&valid_princ_formats[6], "cifs/%s.%s@%s", my_name, lp_realm(), lp_realm()) == -1) {
goto out;
}
ZERO_STRUCT(kt_entry);
ZERO_STRUCT(kt_cursor);
ret = smb_krb5_open_keytab(context, NULL, False, &keytab);
if (ret) {
DEBUG(1, ("ads_keytab_verify_ticket: smb_krb5_open_keytab failed (%s)\n", error_message(ret)));
goto out;
}
/* Iterate through the keytab. For each key, if the principal
* name case-insensitively matches one of the allowed formats,
* try verifying the ticket using that principal. */
ret = krb5_kt_start_seq_get(context, keytab, &kt_cursor);
if (ret) {
DEBUG(1, ("ads_keytab_verify_ticket: krb5_kt_start_seq_get failed (%s)\n", error_message(ret)));
goto out;
}
while (!auth_ok && (krb5_kt_next_entry(context, keytab, &kt_entry, &kt_cursor) == 0)) {
ret = smb_krb5_unparse_name(context, kt_entry.principal, &entry_princ_s);
if (ret) {
DEBUG(1, ("ads_keytab_verify_ticket: smb_krb5_unparse_name failed (%s)\n",
error_message(ret)));
goto out;
}
for (i = 0; i < ARRAY_SIZE(valid_princ_formats); i++) {
if (!strequal(entry_princ_s, valid_princ_formats[i])) {
continue;
}
number_matched_principals++;
packet.length = ticket->length;
packet.data = (char *)ticket->data;
*pp_tkt = NULL;
ret = krb5_rd_req_return_keyblock_from_keytab(context, &auth_context, &packet,
kt_entry.principal, keytab,
NULL, pp_tkt, keyblock);
if (ret) {
DEBUG(10,("ads_keytab_verify_ticket: "
"krb5_rd_req_return_keyblock_from_keytab(%s) failed: %s\n",
entry_princ_s, error_message(ret)));
/* workaround for MIT:
* as krb5_ktfile_get_entry will explicitly
* close the krb5_keytab as soon as krb5_rd_req
* has successfully decrypted the ticket but the
* ticket is not valid yet (due to clockskew)
* there is no point in querying more keytab
* entries - Guenther */
if (ret == KRB5KRB_AP_ERR_TKT_NYV ||
ret == KRB5KRB_AP_ERR_TKT_EXPIRED ||
ret == KRB5KRB_AP_ERR_SKEW) {
break;
}
} else {
DEBUG(3,("ads_keytab_verify_ticket: "
"krb5_rd_req_return_keyblock_from_keytab succeeded for principal %s\n",
entry_princ_s));
auth_ok = True;
break;
}
}
/* Free the name we parsed. */
SAFE_FREE(entry_princ_s);
/* Free the entry we just read. */
smb_krb5_kt_free_entry(context, &kt_entry);
ZERO_STRUCT(kt_entry);
}
krb5_kt_end_seq_get(context, keytab, &kt_cursor);
ZERO_STRUCT(kt_cursor);
out:
for (i = 0; i < ARRAY_SIZE(valid_princ_formats); i++) {
SAFE_FREE(valid_princ_formats[i]);
}
if (!auth_ok) {
if (!number_matched_principals) {
DEBUG(3, ("ads_keytab_verify_ticket: no keytab principals matched expected file service name.\n"));
} else {
DEBUG(3, ("ads_keytab_verify_ticket: krb5_rd_req failed for all %d matched keytab principals\n",
number_matched_principals));
}
}
SAFE_FREE(entry_princ_s);
{
krb5_keytab_entry zero_kt_entry;
ZERO_STRUCT(zero_kt_entry);
if (memcmp(&zero_kt_entry, &kt_entry, sizeof(krb5_keytab_entry))) {
smb_krb5_kt_free_entry(context, &kt_entry);
}
}
{
krb5_kt_cursor zero_csr;
ZERO_STRUCT(zero_csr);
if ((memcmp(&kt_cursor, &zero_csr, sizeof(krb5_kt_cursor)) != 0) && keytab) {
krb5_kt_end_seq_get(context, keytab, &kt_cursor);
}
}
if (keytab) {
krb5_kt_close(context, keytab);
}
*perr = ret;
return auth_ok;
}
static krb5_error_code ads_keytab_verify_for_principal(krb5_context context,
krb5_auth_context auth_context,
const krb5_keytab_entry * kt_entry,
const DATA_BLOB * ticket,
const char * svc_principal,
krb5_ticket ** pp_tkt,
krb5_keyblock ** keyblock)
{
krb5_error_code ret = 0;
krb5_keytab keytab = NULL;
krb5_data packet;
char * entry_princ_s = NULL;
ret = krb5_kt_default(context, &keytab);
if (ret) {
DEBUG(1, ("ads_keytab_verify_for_principal: krb5_kt_default failed (%s)\n", error_message(ret)));
goto out;
}
ret = smb_krb5_unparse_name(context, kt_entry->principal, &entry_princ_s);
if (ret) {
DEBUG(1, ("ads_keytab_verify_for_principal: smb_krb5_unparse_name failed (%s)\n",
error_message(ret)));
goto out;
}
if (!strequal(entry_princ_s, svc_principal)) {
ret = KRB5KRB_AP_ERR_BADMATCH;
goto out;
}
packet.length = ticket->length;
packet.data = (char *)ticket->data;
*pp_tkt = NULL;
ret = krb5_rd_req_return_keyblock_from_keytab(context,
&auth_context, &packet,
kt_entry, keytab,
pp_tkt, keyblock);
if (ret) {
DEBUG(3,("ads_keytab_verify_for_principal: "
"failed for principal %s: %s\n",
entry_princ_s, error_message(ret)));
goto out;
}
DEBUG(3,("ads_keytab_verify_for_principal: succeeded for principal %s\n",
entry_princ_s));
out:
/* Free the name we parsed. */
SAFE_FREE(entry_princ_s);
if (keytab) {
krb5_kt_close(context, keytab);
keytab = NULL;
}
return ret;
}
