Adding upstream version 2:4.20.0+dfsg.upstream/2%4.20.0+dfsg

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 263 insertions, 0 deletions

diff --git a/source4/rpc_server/drsuapi/writespn.c b/source4/rpc_server/drsuapi/writespn.c
new file mode 100644
index 0000000..ac91999
--- /dev/null
+++ b/source4/rpc_server/drsuapi/writespn.c
@@ -0,0 +1,263 @@
+/*
+   Unix SMB/CIFS implementation.
+
+   implement the DsWriteAccountSpn call
+
+   Copyright (C) Stefan Metzmacher 2009
+   Copyright (C) Andrew Tridgell   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 "rpc_server/dcerpc_server.h"
+#include "dsdb/samdb/samdb.h"
+#include "dsdb/common/util.h"
+#include "system/kerberos.h"
+#include "auth/kerberos/kerberos.h"
+#include "libcli/security/security.h"
+#include "libcli/security/session.h"
+#include "rpc_server/drsuapi/dcesrv_drsuapi.h"
+#include "librpc/gen_ndr/ndr_drsuapi.h"
+#include "auth/session.h"
+
+#undef DBGC_CLASS
+#define DBGC_CLASS            DBGC_DRS_REPL
+
+#undef strcasecmp
+
+/*
+  check that the SPN update should be allowed as an override
+  via sam_ctx_system
+
+  This is only called if the client is not a domain controller or
+  administrator
+ */
+static bool writespn_check_spn(struct drsuapi_bind_state *b_state,
+			       struct dcesrv_call_state *dce_call,
+			       struct ldb_dn *dn,
+			       const char *spn)
+{
+	/*
+	 * we only allow SPN updates if:
+	 *
+	 * 1) they are on the clients own account object
+	 * 2) they are of the form SERVICE/dnshostname
+	 */
+	struct auth_session_info *session_info =
+		dcesrv_call_session_info(dce_call);
+	struct dom_sid *user_sid, *sid;
+	TALLOC_CTX *tmp_ctx = talloc_new(dce_call);
+	struct ldb_result *res;
+	const char *attrs[] = { "objectSID", "dNSHostName", NULL };
+	int ret;
+	krb5_context krb_ctx;
+	krb5_error_code kerr;
+	krb5_principal principal;
+	krb5_data component;
+	const char *dns_name, *dnsHostName;
+
+	/* The service principal name shouldn't be NULL */
+	if (spn == NULL) {
+		talloc_free(tmp_ctx);
+		return false;
+	}
+
+	/*
+	  get the objectSid of the DN that is being modified, and
+	  check it matches the user_sid in their token
+	 */
+
+	ret = dsdb_search_dn(b_state->sam_ctx, tmp_ctx, &res, dn, attrs,
+			     DSDB_SEARCH_ONE_ONLY);
+	if (ret != LDB_SUCCESS) {
+		talloc_free(tmp_ctx);
+		return false;
+	}
+
+	user_sid = &session_info->security_token->sids[PRIMARY_USER_SID_INDEX];
+	sid = samdb_result_dom_sid(tmp_ctx, res->msgs[0], "objectSid");
+	if (sid == NULL) {
+		talloc_free(tmp_ctx);
+		return false;
+	}
+
+	dnsHostName = ldb_msg_find_attr_as_string(res->msgs[0], "dNSHostName",
+						  NULL);
+	if (dnsHostName == NULL) {
+		talloc_free(tmp_ctx);
+		return false;
+	}
+
+	if (!dom_sid_equal(sid, user_sid)) {
+		talloc_free(tmp_ctx);
+		return false;
+	}
+
+	kerr = smb_krb5_init_context_basic(tmp_ctx,
+					   dce_call->conn->dce_ctx->lp_ctx,
+					   &krb_ctx);
+	if (kerr != 0) {
+		talloc_free(tmp_ctx);
+		return false;
+	}
+
+	kerr = krb5_parse_name_flags(krb_ctx, spn, KRB5_PRINCIPAL_PARSE_NO_REALM,
+				     &principal);
+	if (kerr != 0) {
+		krb5_free_context(krb_ctx);
+		talloc_free(tmp_ctx);
+		return false;
+	}
+
+	if (krb5_princ_size(krb_ctx, principal) != 2) {
+		krb5_free_principal(krb_ctx, principal);
+		krb5_free_context(krb_ctx);
+		talloc_free(tmp_ctx);
+		return false;
+	}
+
+	kerr = smb_krb5_princ_component(krb_ctx, principal, 1, &component);
+	if (kerr) {
+		krb5_free_principal(krb_ctx, principal);
+		krb5_free_context(krb_ctx);
+		talloc_free(tmp_ctx);
+		return false;
+	}
+	dns_name = (const char *)component.data;
+
+	if (strcasecmp(dns_name, dnsHostName) != 0) {
+		krb5_free_principal(krb_ctx, principal);
+		krb5_free_context(krb_ctx);
+		talloc_free(tmp_ctx);
+		return false;
+	}
+
+	/* its a simple update on their own account - allow it with
+	 * permissions override */
+	krb5_free_principal(krb_ctx, principal);
+	krb5_free_context(krb_ctx);
+	talloc_free(tmp_ctx);
+
+	return true;
+}
+
+/*
+  drsuapi_DsWriteAccountSpn
+*/
+WERROR dcesrv_drsuapi_DsWriteAccountSpn(struct dcesrv_call_state *dce_call, TALLOC_CTX *mem_ctx,
+					struct drsuapi_DsWriteAccountSpn *r)
+{
+	struct drsuapi_bind_state *b_state;
+	struct dcesrv_handle *h;
+
+	*r->out.level_out = r->in.level;
+
+	DCESRV_PULL_HANDLE_WERR(h, r->in.bind_handle, DRSUAPI_BIND_HANDLE);
+	b_state = h->data;
+
+	r->out.res = talloc(mem_ctx, union drsuapi_DsWriteAccountSpnResult);
+	W_ERROR_HAVE_NO_MEMORY(r->out.res);
+
+	switch (r->in.level) {
+		case 1: {
+			struct drsuapi_DsWriteAccountSpnRequest1 *req;
+			struct ldb_message *msg;
+			uint32_t count;
+			unsigned int i;
+			int ret;
+			unsigned spn_count=0;
+			bool passed_checks = true;
+			struct ldb_context *sam_ctx;
+
+			req = &r->in.req->req1;
+			count = req->count;
+
+			msg = ldb_msg_new(mem_ctx);
+			if (msg == NULL) {
+				return WERR_NOT_ENOUGH_MEMORY;
+			}
+
+			msg->dn = ldb_dn_new(msg, b_state->sam_ctx,
+					     req->object_dn);
+			if ( ! ldb_dn_validate(msg->dn)) {
+				r->out.res->res1.status = WERR_OK;
+				return WERR_OK;
+			}
+
+			/* construct mods */
+			for (i = 0; i < count; i++) {
+				if (!writespn_check_spn(b_state,
+						       dce_call,
+						       msg->dn,
+						       req->spn_names[i].str)) {
+					passed_checks = false;
+				}
+				ret = ldb_msg_add_string(msg,
+							 "servicePrincipalName",
+							 req->spn_names[i].str);
+				if (ret != LDB_SUCCESS) {
+					return WERR_NOT_ENOUGH_MEMORY;
+				}
+				spn_count++;
+			}
+
+			if (msg->num_elements == 0) {
+				DEBUG(2,("No SPNs need changing on %s\n",
+					 ldb_dn_get_linearized(msg->dn)));
+				r->out.res->res1.status = WERR_OK;
+				return WERR_OK;
+			}
+
+			for (i=0;i<msg->num_elements;i++) {
+				switch (req->operation) {
+				case DRSUAPI_DS_SPN_OPERATION_ADD:
+					msg->elements[i].flags = LDB_FLAG_MOD_ADD;
+					break;
+				case DRSUAPI_DS_SPN_OPERATION_REPLACE:
+					msg->elements[i].flags = LDB_FLAG_MOD_REPLACE;
+					break;
+				case DRSUAPI_DS_SPN_OPERATION_DELETE:
+					msg->elements[i].flags = LDB_FLAG_MOD_DELETE;
+					break;
+				}
+			}
+
+			if (passed_checks && b_state->sam_ctx_system) {
+				sam_ctx = b_state->sam_ctx_system;
+			} else {
+				sam_ctx = b_state->sam_ctx;
+			}
+
+			/* Apply to database */
+			ret = dsdb_modify(sam_ctx, msg, DSDB_MODIFY_PERMISSIVE);
+			if (ret != LDB_SUCCESS) {
+				DEBUG(0,("Failed to modify SPNs on %s: %s\n",
+					 ldb_dn_get_linearized(msg->dn),
+					 ldb_errstring(b_state->sam_ctx)));
+				NDR_PRINT_IN_DEBUG(
+					drsuapi_DsWriteAccountSpn, r);
+				r->out.res->res1.status = WERR_ACCESS_DENIED;
+			} else {
+				DEBUG(2,("Modified %u SPNs on %s\n", spn_count,
+					 ldb_dn_get_linearized(msg->dn)));
+				r->out.res->res1.status = WERR_OK;
+			}
+
+			return WERR_OK;
+		}
+	}
+
+	return WERR_INVALID_LEVEL;
+}