CVE-2022-37966 kdc: Assume trust objects support AES by default

As part of matching the behaviour of Windows, assume that trust objects
support AES256, but not RC4, if not specified otherwise.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15219
BUG: https://bugzilla.samba.org/show_bug.cgi?id=15237

Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
(cherry picked from commit 4bb50c868c8ed14372cb7d27e53cdaba265fc33d)

diff --git a/source4/kdc/db-glue.c b/source4/kdc/db-glue.c
index ccf3951463b32256943763ffeef725ef7bee2a35..8becada445711a22eb46ab3831bbaeb7b1b0de17 100644 (file)
--- a/source4/kdc/db-glue.c
+++ b/source4/kdc/db-glue.c
@@ -1472,9 +1472,10 @@ static krb5_error_code samba_kdc_trust_message2entry(krb5_context context,
        NTSTATUS status;
 
        if (dsdb_functional_level(kdc_db_ctx->samdb) >= DS_DOMAIN_FUNCTION_2008) {
+               /* If not told otherwise, Windows now assumes that trusts support AES. */
                supported_enctypes = ldb_msg_find_attr_as_uint(msg,
                                        "msDS-SupportedEncryptionTypes",
-                                       supported_enctypes);
+                                       ENC_HMAC_SHA1_96_AES256);
        }
 
        status = dsdb_trust_parse_tdo_info(mem_ctx, msg, &tdo);