Adding upstream version 2:4.17.12+dfsg.upstream/2%4.17.12+dfsgupstream

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

1 files changed, 284 insertions, 0 deletions

diff --git a/source4/dsdb/common/rodc_helper.c b/source4/dsdb/common/rodc_helper.c
new file mode 100644
index 0000000..e81ecef
--- /dev/null
+++ b/source4/dsdb/common/rodc_helper.c
@@ -0,0 +1,284 @@
+/*
+   Unix SMB/CIFS implementation.
+
+   common sid helper functions
+
+   Copyright (C) Catalyst.NET Ltd 2017
+
+   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 "librpc/gen_ndr/ndr_security.h"
+#include "source4/dsdb/samdb/samdb.h"
+#include "libcli/security/security.h"
+
+/*
+  see if any SIDs in list1 are in list2
+ */
+bool sid_list_match(uint32_t num_sids1,
+		    const struct dom_sid *list1,
+		    uint32_t num_sids2,
+		    const struct dom_sid *list2)
+{
+	unsigned int i, j;
+	/* do we ever have enough SIDs here to worry about O(n^2) ? */
+	for (i=0; i < num_sids1; i++) {
+		for (j=0; j < num_sids2; j++) {
+			if (dom_sid_equal(&list1[i], &list2[j])) {
+				return true;
+			}
+		}
+	}
+	return false;
+}
+
+/*
+ * Return an array of SIDs from a ldb_message given an attribute name assumes
+ * the SIDs are in NDR form (with primary_sid applied on the start).
+ */
+static WERROR samdb_result_sid_array_ndr(struct ldb_context *sam_ctx,
+					 struct ldb_message *msg,
+					 TALLOC_CTX *mem_ctx,
+					 const char *attr,
+					 uint32_t *num_sids,
+					 struct dom_sid **sids,
+					 const struct dom_sid *primary_sid)
+{
+	struct ldb_message_element *el;
+	unsigned int i;
+
+	el = ldb_msg_find_element(msg, attr);
+	if (!el) {
+		*sids = NULL;
+		return WERR_OK;
+	}
+
+	/* Make array long enough for NULL and additional SID */
+	(*sids) = talloc_array(mem_ctx, struct dom_sid,
+			       el->num_values + 1);
+	W_ERROR_HAVE_NO_MEMORY(*sids);
+
+	(*sids)[0] = *primary_sid;
+
+	for (i = 0; i<el->num_values; i++) {
+		enum ndr_err_code ndr_err;
+		struct dom_sid sid = { 0, };
+
+		ndr_err = ndr_pull_struct_blob_all_noalloc(&el->values[i], &sid,
+					       (ndr_pull_flags_fn_t)ndr_pull_dom_sid);
+		if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+			return WERR_INTERNAL_DB_CORRUPTION;
+		}
+		/* Primary SID is already in position zero. */
+		(*sids)[i+1] = sid;
+	}
+
+	*num_sids = i+1;
+
+	return WERR_OK;
+}
+
+/*
+  return an array of SIDs from a ldb_message given an attribute name
+  assumes the SIDs are in extended DN format
+ */
+WERROR samdb_result_sid_array_dn(struct ldb_context *sam_ctx,
+				 struct ldb_message *msg,
+				 TALLOC_CTX *mem_ctx,
+				 const char *attr,
+				 uint32_t *num_sids,
+				 struct dom_sid **sids)
+{
+	struct ldb_message_element *el;
+	unsigned int i;
+
+	el = ldb_msg_find_element(msg, attr);
+	if (!el) {
+		*sids = NULL;
+		return WERR_OK;
+	}
+
+	(*sids) = talloc_array(mem_ctx, struct dom_sid, el->num_values + 1);
+	W_ERROR_HAVE_NO_MEMORY(*sids);
+
+	for (i=0; i<el->num_values; i++) {
+		struct ldb_dn *dn = ldb_dn_from_ldb_val(mem_ctx, sam_ctx, &el->values[i]);
+		NTSTATUS status;
+		struct dom_sid sid = { 0, };
+
+		status = dsdb_get_extended_dn_sid(dn, &sid, "SID");
+		if (!NT_STATUS_IS_OK(status)) {
+			return WERR_INTERNAL_DB_CORRUPTION;
+		}
+		(*sids)[i] = sid;
+	}
+	*num_sids = i;
+
+	return WERR_OK;
+}
+
+WERROR samdb_confirm_rodc_allowed_to_repl_to_sid_list(struct ldb_context *sam_ctx,
+						      const struct dom_sid *rodc_machine_account_sid,
+						      struct ldb_message *rodc_msg,
+						      struct ldb_message *obj_msg,
+						      uint32_t num_token_sids,
+						      struct dom_sid *token_sids)
+{
+	uint32_t num_never_reveal_sids, num_reveal_sids;
+	struct dom_sid *never_reveal_sids, *reveal_sids;
+	TALLOC_CTX *frame = talloc_stackframe();
+	WERROR werr;
+	uint32_t rodc_uac;
+	
+	/*
+	 * We are not allowed to get anyone elses krbtgt secrets (and
+	 * in callers that don't shortcut before this, the RODC should
+	 * not deal with any krbtgt)
+	 */
+	if (samdb_result_dn(sam_ctx, frame,
+			    obj_msg, "msDS-KrbTgtLinkBL", NULL)) {
+		TALLOC_FREE(frame);
+		DBG_INFO("Denied attempt to replicate to/act as a RODC krbtgt trust account %s using RODC: %s\n",
+			 ldb_dn_get_linearized(obj_msg->dn),
+			 ldb_dn_get_linearized(rodc_msg->dn));
+		return WERR_DS_DRA_SECRETS_DENIED;
+	}
+
+	if (ldb_msg_find_attr_as_uint(obj_msg,
+				      "userAccountControl", 0) &
+	    UF_INTERDOMAIN_TRUST_ACCOUNT) {
+		DBG_INFO("Denied attempt to replicate to/act as a inter-domain trust account %s using RODC: %s\n",
+			 ldb_dn_get_linearized(obj_msg->dn),
+			 ldb_dn_get_linearized(rodc_msg->dn));
+		TALLOC_FREE(frame);
+		return WERR_DS_DRA_SECRETS_DENIED;
+	}
+
+	/* Be very sure the RODC is really an RODC */
+	rodc_uac = ldb_msg_find_attr_as_uint(rodc_msg,
+					     "userAccountControl",
+					     0);
+	if ((rodc_uac & UF_PARTIAL_SECRETS_ACCOUNT)
+	    != UF_PARTIAL_SECRETS_ACCOUNT) {
+		DBG_ERR("Attempt to use an RODC account that is not an RODC: %s\n",
+			ldb_dn_get_linearized(rodc_msg->dn));
+		TALLOC_FREE(frame);
+		return WERR_DOMAIN_CONTROLLER_NOT_FOUND;
+	}
+
+	werr = samdb_result_sid_array_dn(sam_ctx, rodc_msg,
+					 frame, "msDS-NeverRevealGroup",
+					 &num_never_reveal_sids,
+					 &never_reveal_sids);
+	if (!W_ERROR_IS_OK(werr)) {
+		DBG_ERR("Failed to parse msDS-NeverRevealGroup on %s: %s\n",
+			ldb_dn_get_linearized(rodc_msg->dn),
+			win_errstr(werr));
+		TALLOC_FREE(frame);
+		return WERR_DS_DRA_SECRETS_DENIED;
+	}
+
+	werr = samdb_result_sid_array_dn(sam_ctx, rodc_msg,
+					 frame, "msDS-RevealOnDemandGroup",
+					 &num_reveal_sids,
+					 &reveal_sids);
+	if (!W_ERROR_IS_OK(werr)) {
+		DBG_ERR("Failed to parse msDS-RevealOnDemandGroup on %s: %s\n",
+			ldb_dn_get_linearized(rodc_msg->dn),
+			win_errstr(werr));
+		TALLOC_FREE(frame);
+		return WERR_DS_DRA_SECRETS_DENIED;
+	}
+
+	/* The RODC can replicate and print tickets for itself. */
+	if (dom_sid_equal(&token_sids[0], rodc_machine_account_sid)) {
+		TALLOC_FREE(frame);
+		return WERR_OK;
+	}
+
+	if (never_reveal_sids &&
+	    sid_list_match(num_token_sids,
+			   token_sids,
+			   num_never_reveal_sids,
+			   never_reveal_sids)) {
+		TALLOC_FREE(frame);
+		return WERR_DS_DRA_SECRETS_DENIED;
+	}
+
+	if (reveal_sids &&
+	    sid_list_match(num_token_sids,
+			   token_sids,
+			   num_reveal_sids,
+			   reveal_sids)) {
+		TALLOC_FREE(frame);
+		return WERR_OK;
+	}
+
+	TALLOC_FREE(frame);
+	return WERR_DS_DRA_SECRETS_DENIED;
+
+}
+
+/*
+ * This is a wrapper for the above that pulls in the tokenGroups
+ * rather than relying on the caller providing those
+ */
+WERROR samdb_confirm_rodc_allowed_to_repl_to(struct ldb_context *sam_ctx,
+					     struct dom_sid *rodc_machine_account_sid,
+					     struct ldb_message *rodc_msg,
+					     struct ldb_message *obj_msg)
+{
+	TALLOC_CTX *frame = talloc_stackframe();
+	WERROR werr;
+	uint32_t num_token_sids;
+	struct dom_sid *token_sids;
+	const struct dom_sid *object_sid = NULL;
+
+	object_sid = samdb_result_dom_sid(frame,
+					  obj_msg,
+					  "objectSid");
+	if (object_sid == NULL) {
+		return WERR_DS_DRA_BAD_DN;
+	}
+	
+	/*
+	 * The SID list needs to include itself as well as the tokenGroups.
+	 *
+	 * TODO determine if sIDHistory is required for this check
+	 */
+	werr = samdb_result_sid_array_ndr(sam_ctx,
+					  obj_msg,
+					  frame, "tokenGroups",
+					  &num_token_sids,
+					  &token_sids,
+					  object_sid);
+	if (!W_ERROR_IS_OK(werr) || token_sids==NULL) {
+		DBG_ERR("Failed to get tokenGroups on %s to confirm access via RODC %s: %s\n",
+			ldb_dn_get_linearized(obj_msg->dn),
+			ldb_dn_get_linearized(rodc_msg->dn),
+			win_errstr(werr));
+		return WERR_DS_DRA_SECRETS_DENIED;
+	}
+
+	werr = samdb_confirm_rodc_allowed_to_repl_to_sid_list(sam_ctx,
+							      rodc_machine_account_sid,
+							      rodc_msg,
+							      obj_msg,
+							      num_token_sids,
+							      token_sids);
+	TALLOC_FREE(frame);
+	return werr;
+}