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-rw-r--r--source3/librpc/crypto/gse_krb5.c609
1 files changed, 609 insertions, 0 deletions
diff --git a/source3/librpc/crypto/gse_krb5.c b/source3/librpc/crypto/gse_krb5.c
new file mode 100644
index 0000000..f1e0e51
--- /dev/null
+++ b/source3/librpc/crypto/gse_krb5.c
@@ -0,0 +1,609 @@
+/*
+ * GSSAPI Security Extensions
+ * Krb5 helpers
+ * Copyright (C) Simo Sorce 2010.
+ *
+ * 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 "includes.h"
+#include "smb_krb5.h"
+#include "secrets.h"
+#include "librpc/gen_ndr/secrets.h"
+#include "gse_krb5.h"
+#include "lib/param/loadparm.h"
+#include "libads/kerberos_proto.h"
+#include "lib/util/string_wrappers.h"
+
+#ifdef HAVE_KRB5
+
+static krb5_error_code flush_keytab(krb5_context krbctx, krb5_keytab keytab)
+{
+ krb5_error_code ret;
+ krb5_kt_cursor kt_cursor;
+ krb5_keytab_entry kt_entry;
+
+ ZERO_STRUCT(kt_entry);
+
+ ret = krb5_kt_start_seq_get(krbctx, keytab, &kt_cursor);
+ if (ret != 0) {
+ return ret;
+ }
+
+ ret = krb5_kt_next_entry(krbctx, keytab, &kt_entry, &kt_cursor);
+ while (ret == 0) {
+
+ /* we need to close and reopen enumeration because we modify
+ * the keytab */
+ ret = krb5_kt_end_seq_get(krbctx, keytab, &kt_cursor);
+ if (ret != 0) {
+ DEBUG(1, (__location__ ": krb5_kt_end_seq_get() "
+ "failed (%s)\n", error_message(ret)));
+ goto out;
+ }
+
+ /* remove the entry */
+ ret = krb5_kt_remove_entry(krbctx, keytab, &kt_entry);
+ if (ret != 0) {
+ DEBUG(1, (__location__ ": krb5_kt_remove_entry() "
+ "failed (%s)\n", error_message(ret)));
+ goto out;
+ }
+ smb_krb5_kt_free_entry(krbctx, &kt_entry);
+ ZERO_STRUCT(kt_entry);
+
+ /* now reopen */
+ ret = krb5_kt_start_seq_get(krbctx, keytab, &kt_cursor);
+ if (ret != 0) {
+ DEBUG(1, (__location__ ": krb5_kt_start_seq() failed "
+ "(%s)\n", error_message(ret)));
+ goto out;
+ }
+
+ ret = krb5_kt_next_entry(krbctx, keytab,
+ &kt_entry, &kt_cursor);
+ }
+
+ if (ret != KRB5_KT_END && ret != ENOENT) {
+ DEBUG(1, (__location__ ": flushing keytab we got [%s]!\n",
+ error_message(ret)));
+ }
+
+ ret = krb5_kt_end_seq_get(krbctx, keytab, &kt_cursor);
+ if (ret != 0) {
+ DEBUG(1, (__location__ ": krb5_kt_end_seq_get() "
+ "failed (%s)\n", error_message(ret)));
+ goto out;
+ }
+ ret = 0;
+
+out:
+ return ret;
+}
+
+static krb5_error_code fill_keytab_from_password(krb5_context krbctx,
+ krb5_keytab keytab,
+ krb5_principal princ,
+ krb5_kvno vno,
+ struct secrets_domain_info1_password *pw)
+{
+ krb5_error_code ret;
+ krb5_enctype *enctypes;
+ uint16_t i;
+
+ ret = smb_krb5_get_allowed_etypes(krbctx, &enctypes);
+ if (ret) {
+ DEBUG(1, (__location__
+ ": Can't determine permitted enctypes!\n"));
+ return ret;
+ }
+
+ for (i = 0; i < pw->num_keys; i++) {
+ krb5_keytab_entry kt_entry;
+ krb5_keyblock *key = NULL;
+ unsigned int ei;
+ bool found_etype = false;
+
+ for (ei=0; enctypes[ei] != 0; ei++) {
+ if ((uint32_t)enctypes[ei] != pw->keys[i].keytype) {
+ continue;
+ }
+
+ found_etype = true;
+ break;
+ }
+
+ if (!found_etype) {
+ continue;
+ }
+
+ ZERO_STRUCT(kt_entry);
+ kt_entry.principal = princ;
+ kt_entry.vno = vno;
+
+ key = KRB5_KT_KEY(&kt_entry);
+ KRB5_KEY_TYPE(key) = pw->keys[i].keytype;
+ KRB5_KEY_DATA(key) = pw->keys[i].value.data;
+ KRB5_KEY_LENGTH(key) = pw->keys[i].value.length;
+
+ ret = krb5_kt_add_entry(krbctx, keytab, &kt_entry);
+ if (ret) {
+ DEBUG(1, (__location__ ": Failed to add entry to "
+ "keytab for enctype %d (error: %s)\n",
+ (unsigned)pw->keys[i].keytype,
+ error_message(ret)));
+ goto out;
+ }
+ }
+
+ ret = 0;
+
+out:
+ krb5_free_enctypes(krbctx, enctypes);
+ return ret;
+}
+
+#define SRV_MEM_KEYTAB_NAME "MEMORY:cifs_srv_keytab"
+#define CLEARTEXT_PRIV_ENCTYPE -99
+
+static krb5_error_code fill_mem_keytab_from_secrets(krb5_context krbctx,
+ krb5_keytab *keytab)
+{
+ TALLOC_CTX *frame = talloc_stackframe();
+ krb5_error_code ret, ret2;
+ const char *domain = lp_workgroup();
+ struct secrets_domain_info1 *info = NULL;
+ const char *realm = NULL;
+ const DATA_BLOB *ct = NULL;
+ krb5_kt_cursor kt_cursor;
+ krb5_keytab_entry kt_entry;
+ krb5_principal princ = NULL;
+ krb5_kvno kvno = 0; /* FIXME: fetch current vno from KDC ? */
+ NTSTATUS status;
+
+ if (!secrets_init()) {
+ DEBUG(1, (__location__ ": secrets_init failed\n"));
+ TALLOC_FREE(frame);
+ return KRB5_CONFIG_CANTOPEN;
+ }
+
+ status = secrets_fetch_or_upgrade_domain_info(domain,
+ frame,
+ &info);
+ if (!NT_STATUS_IS_OK(status)) {
+ DBG_WARNING("secrets_fetch_or_upgrade_domain_info(%s) - %s\n",
+ domain, nt_errstr(status));
+ TALLOC_FREE(frame);
+ return KRB5_LIBOS_CANTREADPWD;
+ }
+ ct = &info->password->cleartext_blob;
+
+ if (info->domain_info.dns_domain.string != NULL) {
+ realm = strupper_talloc(frame,
+ info->domain_info.dns_domain.string);
+ if (realm == NULL) {
+ TALLOC_FREE(frame);
+ return ENOMEM;
+ }
+ }
+
+ ZERO_STRUCT(kt_entry);
+ ZERO_STRUCT(kt_cursor);
+
+ /* check if the keytab already has any entry */
+ ret = krb5_kt_start_seq_get(krbctx, *keytab, &kt_cursor);
+ if (ret != 0) {
+ goto out;
+ }
+
+ /* check if we have our special enctype used to hold
+ * the clear text password. If so, check it out so that
+ * we can verify if the keytab needs to be upgraded */
+ while ((ret = krb5_kt_next_entry(krbctx, *keytab,
+ &kt_entry, &kt_cursor)) == 0) {
+ if (smb_krb5_kt_get_enctype_from_entry(&kt_entry) ==
+ CLEARTEXT_PRIV_ENCTYPE) {
+ break;
+ }
+ smb_krb5_kt_free_entry(krbctx, &kt_entry);
+ ZERO_STRUCT(kt_entry);
+ }
+
+ ret2 = krb5_kt_end_seq_get(krbctx, *keytab, &kt_cursor);
+ if (ret2 != 0) {
+ ret = ret2;
+ DEBUG(1, (__location__ ": krb5_kt_end_seq_get() "
+ "failed (%s)\n", error_message(ret)));
+ goto out;
+ }
+
+ if (ret != 0 && ret != KRB5_KT_END && ret != ENOENT ) {
+ /* Error parsing keytab */
+ DEBUG(1, (__location__ ": Failed to parse memory "
+ "keytab!\n"));
+ goto out;
+ }
+
+ if (ret == 0) {
+ /* found private entry,
+ * check if keytab is up to date */
+
+ if ((ct->length == KRB5_KEY_LENGTH(KRB5_KT_KEY(&kt_entry))) &&
+ (mem_equal_const_time(KRB5_KEY_DATA(KRB5_KT_KEY(&kt_entry)),
+ ct->data, ct->length))) {
+ /* keytab is already up to date, return */
+ smb_krb5_kt_free_entry(krbctx, &kt_entry);
+ goto out;
+ }
+
+ smb_krb5_kt_free_entry(krbctx, &kt_entry);
+ ZERO_STRUCT(kt_entry);
+
+
+ /* flush keytab, we need to regen it */
+ ret = flush_keytab(krbctx, *keytab);
+ if (ret) {
+ DEBUG(1, (__location__ ": Failed to flush "
+ "memory keytab!\n"));
+ goto out;
+ }
+ }
+
+ /* keytab is not up to date, fill it up */
+
+ ret = smb_krb5_make_principal(krbctx, &princ, realm,
+ info->account_name, NULL);
+ if (ret) {
+ DEBUG(1, (__location__ ": Failed to get host principal!\n"));
+ goto out;
+ }
+
+ ret = fill_keytab_from_password(krbctx, *keytab,
+ princ, kvno,
+ info->password);
+ if (ret) {
+ DBG_WARNING("fill_keytab_from_password() failed for "
+ "info->password.\n.");
+ goto out;
+ }
+
+ if (info->old_password != NULL) {
+ ret = fill_keytab_from_password(krbctx, *keytab,
+ princ, kvno - 1,
+ info->old_password);
+ if (ret) {
+ DBG_WARNING("fill_keytab_from_password() failed for "
+ "info->old_password.\n.");
+ goto out;
+ }
+ }
+
+ if (info->older_password != NULL) {
+ ret = fill_keytab_from_password(krbctx, *keytab,
+ princ, kvno - 2,
+ info->older_password);
+ if (ret) {
+ DBG_WARNING("fill_keytab_from_password() failed for "
+ "info->older_password.\n.");
+ goto out;
+ }
+ }
+
+ if (info->next_change != NULL) {
+ ret = fill_keytab_from_password(krbctx, *keytab,
+ princ, kvno - 3,
+ info->next_change->password);
+ if (ret) {
+ DBG_WARNING("fill_keytab_from_password() failed for "
+ "info->next_change->password.\n.");
+ goto out;
+ }
+ }
+
+ /* add our private enctype + cleartext password so that we can
+ * update the keytab if secrets change later on */
+ ZERO_STRUCT(kt_entry);
+ kt_entry.principal = princ;
+ kt_entry.vno = 0;
+
+ KRB5_KEY_TYPE(KRB5_KT_KEY(&kt_entry)) = CLEARTEXT_PRIV_ENCTYPE;
+ KRB5_KEY_LENGTH(KRB5_KT_KEY(&kt_entry)) = ct->length;
+ KRB5_KEY_DATA(KRB5_KT_KEY(&kt_entry)) = ct->data;
+
+ ret = krb5_kt_add_entry(krbctx, *keytab, &kt_entry);
+ if (ret) {
+ DEBUG(1, (__location__ ": Failed to add entry to "
+ "keytab for private enctype (%d) (error: %s)\n",
+ CLEARTEXT_PRIV_ENCTYPE, error_message(ret)));
+ goto out;
+ }
+
+ ret = 0;
+
+out:
+
+ if (princ) {
+ krb5_free_principal(krbctx, princ);
+ }
+
+ TALLOC_FREE(frame);
+ return ret;
+}
+
+static krb5_error_code fill_mem_keytab_from_system_keytab(krb5_context krbctx,
+ krb5_keytab *mkeytab)
+{
+ krb5_error_code ret = 0;
+ krb5_keytab keytab = NULL;
+ krb5_kt_cursor kt_cursor = { 0, };
+ krb5_keytab_entry kt_entry = { 0, };
+ char *valid_princ_formats[7] = { NULL, NULL, NULL,
+ NULL, NULL, NULL, NULL };
+ char *entry_princ_s = NULL;
+ fstring my_name, my_fqdn;
+ unsigned i;
+ int err;
+
+ /* Generate the list of principal names which we expect
+ * clients might want to use for authenticating to the file
+ * service. We allow name$,{host,cifs}/{name,fqdn,name.REALM}. */
+
+ fstrcpy(my_name, lp_netbios_name());
+
+ my_fqdn[0] = '\0';
+ name_to_fqdn(my_fqdn, lp_netbios_name());
+
+ err = asprintf(&valid_princ_formats[0],
+ "%s$@%s", my_name, lp_realm());
+ if (err == -1) {
+ ret = ENOMEM;
+ goto out;
+ }
+ err = asprintf(&valid_princ_formats[1],
+ "host/%s@%s", my_name, lp_realm());
+ if (err == -1) {
+ ret = ENOMEM;
+ goto out;
+ }
+ err = asprintf(&valid_princ_formats[2],
+ "host/%s@%s", my_fqdn, lp_realm());
+ if (err == -1) {
+ ret = ENOMEM;
+ goto out;
+ }
+ err = asprintf(&valid_princ_formats[3],
+ "host/%s.%s@%s", my_name, lp_realm(), lp_realm());
+ if (err == -1) {
+ ret = ENOMEM;
+ goto out;
+ }
+ err = asprintf(&valid_princ_formats[4],
+ "cifs/%s@%s", my_name, lp_realm());
+ if (err == -1) {
+ ret = ENOMEM;
+ goto out;
+ }
+ err = asprintf(&valid_princ_formats[5],
+ "cifs/%s@%s", my_fqdn, lp_realm());
+ if (err == -1) {
+ ret = ENOMEM;
+ goto out;
+ }
+ err = asprintf(&valid_princ_formats[6],
+ "cifs/%s.%s@%s", my_name, lp_realm(), lp_realm());
+ if (err == -1) {
+ ret = ENOMEM;
+ goto out;
+ }
+
+ ret = smb_krb5_kt_open_relative(krbctx, NULL, false, &keytab);
+ if (ret) {
+ DEBUG(1, ("smb_krb5_kt_open 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,
+ * copy it to the memory keytab.
+ */
+
+ ret = krb5_kt_start_seq_get(krbctx, keytab, &kt_cursor);
+ if (ret) {
+ DEBUG(1, (__location__ ": krb5_kt_start_seq_get failed (%s)\n",
+ error_message(ret)));
+ /*
+ * krb5_kt_start_seq_get() may leaves bogus data
+ * in kt_cursor. And we want to use the all_zero()
+ * logic below.
+ *
+ * See bug #10490
+ */
+ ZERO_STRUCT(kt_cursor);
+ goto out;
+ }
+
+ while ((krb5_kt_next_entry(krbctx, keytab,
+ &kt_entry, &kt_cursor) == 0)) {
+ ret = smb_krb5_unparse_name(talloc_tos(), krbctx,
+ kt_entry.principal,
+ &entry_princ_s);
+ if (ret) {
+ DEBUG(1, (__location__ ": 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;
+ }
+
+ ret = krb5_kt_add_entry(krbctx, *mkeytab, &kt_entry);
+ if (ret) {
+ DEBUG(1, (__location__ ": smb_krb5_unparse_name "
+ "failed (%s)\n", error_message(ret)));
+ goto out;
+ }
+ }
+
+ /* Free the name we parsed. */
+ TALLOC_FREE(entry_princ_s);
+
+ /* Free the entry we just read. */
+ smb_krb5_kt_free_entry(krbctx, &kt_entry);
+ ZERO_STRUCT(kt_entry);
+ }
+ krb5_kt_end_seq_get(krbctx, keytab, &kt_cursor);
+
+ ZERO_STRUCT(kt_cursor);
+
+out:
+
+ for (i = 0; i < ARRAY_SIZE(valid_princ_formats); i++) {
+ SAFE_FREE(valid_princ_formats[i]);
+ }
+
+ TALLOC_FREE(entry_princ_s);
+
+ if (!all_zero((uint8_t *)&kt_entry, sizeof(kt_entry))) {
+ smb_krb5_kt_free_entry(krbctx, &kt_entry);
+ }
+
+ if (!all_zero((uint8_t *)&kt_cursor, sizeof(kt_cursor)) && keytab) {
+ krb5_kt_end_seq_get(krbctx, keytab, &kt_cursor);
+ }
+
+ if (keytab) {
+ krb5_kt_close(krbctx, keytab);
+ }
+
+ return ret;
+}
+
+static krb5_error_code fill_mem_keytab_from_dedicated_keytab(krb5_context krbctx,
+ krb5_keytab *mkeytab)
+{
+ krb5_error_code ret = 0;
+ krb5_keytab keytab = NULL;
+ krb5_kt_cursor kt_cursor;
+ krb5_keytab_entry kt_entry;
+
+ ret = smb_krb5_kt_open(krbctx, lp_dedicated_keytab_file(),
+ false, &keytab);
+ if (ret) {
+ DEBUG(1, ("smb_krb5_kt_open of %s failed (%s)\n",
+ lp_dedicated_keytab_file(),
+ error_message(ret)));
+ return ret;
+ }
+
+ /*
+ * Copy the dedicated keyab to our in-memory keytab.
+ */
+
+ ret = krb5_kt_start_seq_get(krbctx, keytab, &kt_cursor);
+ if (ret) {
+ DEBUG(1, (__location__ ": krb5_kt_start_seq_get on %s "
+ "failed (%s)\n",
+ lp_dedicated_keytab_file(),
+ error_message(ret)));
+ goto out;
+ }
+
+ while ((krb5_kt_next_entry(krbctx, keytab,
+ &kt_entry, &kt_cursor) == 0)) {
+
+ ret = krb5_kt_add_entry(krbctx, *mkeytab, &kt_entry);
+
+ /* Free the entry we just read. */
+ smb_krb5_kt_free_entry(krbctx, &kt_entry);
+
+ if (ret) {
+ DEBUG(1, (__location__ ": smb_krb5_unparse_name "
+ "failed (%s)\n", error_message(ret)));
+ break;
+ }
+ }
+ krb5_kt_end_seq_get(krbctx, keytab, &kt_cursor);
+
+out:
+
+ krb5_kt_close(krbctx, keytab);
+
+ return ret;
+}
+
+krb5_error_code gse_krb5_get_server_keytab(krb5_context krbctx,
+ krb5_keytab *keytab)
+{
+ krb5_error_code ret = 0;
+ krb5_error_code ret1 = 0;
+ krb5_error_code ret2 = 0;
+
+ *keytab = NULL;
+
+ /* create memory keytab */
+ ret = krb5_kt_resolve(krbctx, SRV_MEM_KEYTAB_NAME, keytab);
+ if (ret) {
+ DEBUG(1, (__location__ ": Failed to get memory "
+ "keytab!\n"));
+ return ret;
+ }
+
+ switch (lp_kerberos_method()) {
+ default:
+ case KERBEROS_VERIFY_SECRETS:
+ ret = fill_mem_keytab_from_secrets(krbctx, keytab);
+ break;
+ case KERBEROS_VERIFY_SYSTEM_KEYTAB:
+ ret = fill_mem_keytab_from_system_keytab(krbctx, keytab);
+ break;
+ case KERBEROS_VERIFY_DEDICATED_KEYTAB:
+ /* just use whatever keytab is configured */
+ ret = fill_mem_keytab_from_dedicated_keytab(krbctx, keytab);
+ break;
+ case KERBEROS_VERIFY_SECRETS_AND_KEYTAB:
+ ret1 = fill_mem_keytab_from_secrets(krbctx, keytab);
+ if (ret1) {
+ DEBUG(3, (__location__ ": Warning! Unable to set mem "
+ "keytab from secrets!\n"));
+ }
+ /* Now append system keytab keys too */
+ ret2 = fill_mem_keytab_from_system_keytab(krbctx, keytab);
+ if (ret2) {
+ DEBUG(3, (__location__ ": Warning! Unable to set mem "
+ "keytab from system keytab!\n"));
+ }
+ if (ret1 == 0 || ret2 == 0) {
+ ret = 0;
+ } else {
+ ret = ret1;
+ }
+ break;
+ }
+
+ if (ret) {
+ krb5_kt_close(krbctx, *keytab);
+ *keytab = NULL;
+ DEBUG(1,("%s: Error! Unable to set mem keytab - %d\n",
+ __location__, ret));
+ }
+
+ return ret;
+}
+
+#endif /* HAVE_KRB5 */
generated by cgit v1.2.3 (git 2.39.1) at 2024-10-30 13:18:20 +0000