CVE-2020-1472(ZeroLogon): torture: ServerSetPassword2 confounder

Test that a confounder that encrypts to itself is rejected

Signed-off-by: Gary Lockyer <gary@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

diff --git a/source4/torture/rpc/netlogon.c b/source4/torture/rpc/netlogon.c
index 4f55887c5711f4f319d0d4a760aec858f3ef890b..6ac550c701215e28041287aec221f1fe86544a32 100644 (file)
--- a/source4/torture/rpc/netlogon.c
+++ b/source4/torture/rpc/netlogon.c
@@ -1431,6 +1431,83 @@ static bool test_SetPassword2_password_encrypts_to_zero(
 
        return true;
 }
+/*
+ * Check that an all zero confounder, that encrypts to all zeros is
+ * rejected.
+ *
+ * Note: The test does use sign and seal, it's purpose is to exercise
+ *       the detection code in dcesrv_netr_ServerPasswordSet2
+ */
+static bool test_SetPassword2_confounder(
+       struct torture_context *tctx,
+       struct dcerpc_pipe *p1,
+       struct cli_credentials *machine_credentials)
+{
+       struct netr_ServerPasswordSet2 r;
+       struct netlogon_creds_CredentialState *creds;
+       struct samr_CryptPassword password_buf;
+       struct netr_Authenticator credential, return_authenticator;
+       struct netr_CryptPassword new_password;
+       struct dcerpc_pipe *p = NULL;
+       struct dcerpc_binding_handle *b = NULL;
+
+       if (!test_ServerAuthenticate2_encrypts_to_zero(
+               tctx,
+               p1,
+               machine_credentials,
+               '\0',
+               &creds)) {
+
+               return false;
+       }
+
+       if (!test_SetupCredentialsPipe(
+               p1,
+               tctx,
+               machine_credentials,
+               creds,
+               DCERPC_SIGN | DCERPC_SEAL,
+               &p))
+       {
+               return false;
+       }
+       b = p->binding_handle;
+
+       r.in.server_name = talloc_asprintf(
+               tctx,
+               "\\\\%s", dcerpc_server_name(p));
+       r.in.account_name = talloc_asprintf(tctx, "%s$", TEST_MACHINE_NAME);
+       r.in.secure_channel_type =
+               cli_credentials_get_secure_channel_type(machine_credentials);
+       r.in.computer_name = TEST_MACHINE_NAME;
+       r.in.credential = &credential;
+       r.in.new_password = &new_password;
+       r.out.return_authenticator = &return_authenticator;
+
+       ZERO_STRUCT(password_buf);
+       password_buf.data[511] = 'A';
+       SIVAL(password_buf.data, 512, 2);
+
+       if (!(creds->negotiate_flags & NETLOGON_NEG_SUPPORTS_AES)) {
+               torture_fail(tctx, "NETLOGON_NEG_SUPPORTS_AES not set");
+       }
+       netlogon_creds_aes_encrypt(creds, password_buf.data, 516);
+
+       memcpy(new_password.data, password_buf.data, 512);
+       new_password.length = IVAL(password_buf.data, 512);
+
+       netlogon_creds_client_authenticator(creds, &credential);
+
+       torture_assert_ntstatus_ok(
+               tctx,
+               dcerpc_netr_ServerPasswordSet2_r(b, tctx, &r),
+               "ServerPasswordSet2 confounder check failed");
+       torture_assert_ntstatus_equal(
+               tctx, r.out.result, NT_STATUS_WRONG_PASSWORD, "");
+
+       return true;
+}
+
 
 static bool test_SetPassword2(struct torture_context *tctx,
                              struct dcerpc_pipe *p,
@@ -5598,6 +5675,10 @@ struct torture_suite *torture_rpc_netlogon_zerologon(TALLOC_CTX *mem_ctx)
                tcase,
                "test_SetPassword2_password_encrypts_to_zero",
                test_SetPassword2_password_encrypts_to_zero);
+       torture_rpc_tcase_add_test_creds(
+               tcase,
+               "test_SetPassword2_confounder",
+               test_SetPassword2_confounder);
 
        return suite;
 }