CVE-2022-38023 s4:rpc_server/netlogon: defer downgrade check until we found the accou...

We'll soon make it possible to use 'reject md5 servers:CLIENTACCOUNT$ = no',
which means we'll need use the account name from our SAM.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15240

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>

diff --git a/source4/rpc_server/netlogon/dcerpc_netlogon.c b/source4/rpc_server/netlogon/dcerpc_netlogon.c
index 51e8dd42cdcec92830211e48bde03c8fb150d300..bf545adc45a94d3cab648025fe5f6af56f2916a1 100644 (file)
--- a/source4/rpc_server/netlogon/dcerpc_netlogon.c
+++ b/source4/rpc_server/netlogon/dcerpc_netlogon.c
@@ -311,13 +311,6 @@ static NTSTATUS dcesrv_netr_ServerAuthenticate3_helper(
 
        negotiate_flags = *r->in.negotiate_flags & server_flags;
 
-       nt_status = dcesrv_netr_ServerAuthenticate3_check_downgrade(
-                       dce_call, r, pipe_state, negotiate_flags,
-                       NT_STATUS_OK);
-       if (!NT_STATUS_IS_OK(nt_status)) {
-               return nt_status;
-       }
-
        switch (r->in.secure_channel_type) {
        case SEC_CHAN_WKSTA:
        case SEC_CHAN_DNS_DOMAIN:
@@ -326,16 +319,22 @@ static NTSTATUS dcesrv_netr_ServerAuthenticate3_helper(
        case SEC_CHAN_RODC:
                break;
        case SEC_CHAN_NULL:
-               return NT_STATUS_INVALID_PARAMETER;
+               return dcesrv_netr_ServerAuthenticate3_check_downgrade(
+                               dce_call, r, pipe_state, negotiate_flags,
+                               NT_STATUS_INVALID_PARAMETER);
        default:
                DEBUG(1, ("Client asked for an invalid secure channel type: %d\n",
                          r->in.secure_channel_type));
-               return NT_STATUS_INVALID_PARAMETER;
+               return dcesrv_netr_ServerAuthenticate3_check_downgrade(
+                               dce_call, r, pipe_state, negotiate_flags,
+                               NT_STATUS_INVALID_PARAMETER);
        }
 
        sam_ctx = dcesrv_samdb_connect_as_system(mem_ctx, dce_call);
        if (sam_ctx == NULL) {
-               return NT_STATUS_INVALID_SYSTEM_SERVICE;
+               return dcesrv_netr_ServerAuthenticate3_check_downgrade(
+                               dce_call, r, pipe_state, negotiate_flags,
+                               NT_STATUS_INVALID_SYSTEM_SERVICE);
        }
 
        if (r->in.secure_channel_type == SEC_CHAN_DOMAIN ||
@@ -364,16 +363,22 @@ static NTSTATUS dcesrv_netr_ServerAuthenticate3_helper(
                encoded_name = ldb_binary_encode_string(mem_ctx,
                                                        r->in.account_name);
                if (encoded_name == NULL) {
-                       return NT_STATUS_NO_MEMORY;
+                       return dcesrv_netr_ServerAuthenticate3_check_downgrade(
+                               dce_call, r, pipe_state, negotiate_flags,
+                               NT_STATUS_NO_MEMORY);
                }
 
                len = strlen(encoded_name);
                if (len < 2) {
-                       return NT_STATUS_NO_TRUST_SAM_ACCOUNT;
+                       return dcesrv_netr_ServerAuthenticate3_check_downgrade(
+                               dce_call, r, pipe_state, negotiate_flags,
+                               NT_STATUS_NO_TRUST_SAM_ACCOUNT);
                }
 
                if (require_trailer && encoded_name[len - 1] != trailer) {
-                       return NT_STATUS_NO_TRUST_SAM_ACCOUNT;
+                       return dcesrv_netr_ServerAuthenticate3_check_downgrade(
+                               dce_call, r, pipe_state, negotiate_flags,
+                               NT_STATUS_NO_TRUST_SAM_ACCOUNT);
                }
                encoded_name[len - 1] = '\0';
 
@@ -391,30 +396,42 @@ static NTSTATUS dcesrv_netr_ServerAuthenticate3_helper(
                                  "but there's no tdo for [%s] => [%s] \n",
                                  log_escape(mem_ctx, r->in.account_name),
                                  encoded_name));
-                       return NT_STATUS_NO_TRUST_SAM_ACCOUNT;
+                       return dcesrv_netr_ServerAuthenticate3_check_downgrade(
+                               dce_call, r, pipe_state, negotiate_flags,
+                               NT_STATUS_NO_TRUST_SAM_ACCOUNT);
                }
                if (!NT_STATUS_IS_OK(nt_status)) {
-                       return nt_status;
+                       return dcesrv_netr_ServerAuthenticate3_check_downgrade(
+                               dce_call, r, pipe_state, negotiate_flags,
+                               nt_status);
                }
 
                nt_status = dsdb_trust_get_incoming_passwords(tdo_msg, mem_ctx,
                                                              &curNtHash,
                                                              &prevNtHash);
                if (NT_STATUS_EQUAL(nt_status, NT_STATUS_ACCOUNT_DISABLED)) {
-                       return NT_STATUS_NO_TRUST_SAM_ACCOUNT;
+                       return dcesrv_netr_ServerAuthenticate3_check_downgrade(
+                               dce_call, r, pipe_state, negotiate_flags,
+                               NT_STATUS_NO_TRUST_SAM_ACCOUNT);
                }
                if (!NT_STATUS_IS_OK(nt_status)) {
-                       return nt_status;
+                       return dcesrv_netr_ServerAuthenticate3_check_downgrade(
+                               dce_call, r, pipe_state, negotiate_flags,
+                               nt_status);
                }
 
                flatname = ldb_msg_find_attr_as_string(tdo_msg, "flatName", NULL);
                if (flatname == NULL) {
-                       return NT_STATUS_NO_TRUST_SAM_ACCOUNT;
+                       return dcesrv_netr_ServerAuthenticate3_check_downgrade(
+                               dce_call, r, pipe_state, negotiate_flags,
+                               NT_STATUS_NO_TRUST_SAM_ACCOUNT);
                }
 
                *trust_account_for_search = talloc_asprintf(mem_ctx, "%s$", flatname);
                if (*trust_account_for_search == NULL) {
-                       return NT_STATUS_NO_MEMORY;
+                       return dcesrv_netr_ServerAuthenticate3_check_downgrade(
+                               dce_call, r, pipe_state, negotiate_flags,
+                               NT_STATUS_NO_MEMORY);
                }
        } else {
                *trust_account_for_search = r->in.account_name;
@@ -429,14 +446,18 @@ static NTSTATUS dcesrv_netr_ServerAuthenticate3_helper(
        if (num_records == 0) {
                DEBUG(3,("Couldn't find user [%s] in samdb.\n",
                         log_escape(mem_ctx, r->in.account_name)));
-               return NT_STATUS_NO_TRUST_SAM_ACCOUNT;
+               return dcesrv_netr_ServerAuthenticate3_check_downgrade(
+                               dce_call, r, pipe_state, negotiate_flags,
+                               NT_STATUS_NO_TRUST_SAM_ACCOUNT);
        }
 
        if (num_records > 1) {
                DEBUG(0,("Found %d records matching user [%s]\n",
                         num_records,
                         log_escape(mem_ctx, r->in.account_name)));
-               return NT_STATUS_INTERNAL_DB_CORRUPTION;
+               return dcesrv_netr_ServerAuthenticate3_check_downgrade(
+                               dce_call, r, pipe_state, negotiate_flags,
+                               NT_STATUS_INTERNAL_DB_CORRUPTION);
        }
 
        *trust_account_in_db = ldb_msg_find_attr_as_string(msgs[0],
@@ -445,9 +466,18 @@ static NTSTATUS dcesrv_netr_ServerAuthenticate3_helper(
        if (*trust_account_in_db == NULL) {
                DEBUG(0,("No samAccountName returned in record matching user [%s]\n",
                         r->in.account_name));
-               return NT_STATUS_INTERNAL_DB_CORRUPTION;
+               return dcesrv_netr_ServerAuthenticate3_check_downgrade(
+                               dce_call, r, pipe_state, negotiate_flags,
+                               NT_STATUS_INTERNAL_DB_CORRUPTION);
        }
-       
+
+       nt_status = dcesrv_netr_ServerAuthenticate3_check_downgrade(
+                       dce_call, r, pipe_state, negotiate_flags,
+                       NT_STATUS_OK);
+       if (!NT_STATUS_IS_OK(nt_status)) {
+               return nt_status;
+       }
+
        user_account_control = ldb_msg_find_attr_as_uint(msgs[0], "userAccountControl", 0);
 
        if (user_account_control & UF_ACCOUNTDISABLE) {