samba-mirror/lib/fuzzing/fuzz_sddl_conditional_ace.c

/*
  Fuzz sddl conditional ace decoding and encoding
  Copyright (C) Catalyst IT 2023

  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 "replace.h"
#include "libcli/security/security.h"
#include "lib/util/attr.h"
#include "librpc/gen_ndr/ndr_security.h"
#include "libcli/security/conditional_ace.h"
#include "librpc/gen_ndr/conditional_ace.h"
#include "fuzzing/fuzzing.h"


#define MAX_LENGTH (1024 * 1024 - 1)
static char sddl_string[MAX_LENGTH + 1] = {0};


int LLVMFuzzerInitialize(int *argc, char ***argv)
{
	return 0;
}


int LLVMFuzzerTestOneInput(const uint8_t *input, size_t len)
{
	TALLOC_CTX *mem_ctx = NULL;
	bool ok;
	struct ace_condition_script *s1 = NULL;
	struct ace_condition_script *s2 = NULL;
	const char *message = NULL;
	size_t message_offset;
	const char *resddl = NULL;
	DATA_BLOB e1, e2, e3;
	size_t length;

	if (len > MAX_LENGTH) {
		return 0;
	}

	memcpy(sddl_string, input, len);
	sddl_string[len] = '\0';

	mem_ctx = talloc_new(NULL);

	s1 = ace_conditions_compile_sddl(mem_ctx,
					 ACE_CONDITION_FLAG_ALLOW_DEVICE,
					 sddl_string,
					 &message,
					 &message_offset,
					 &length);
	if (s1 == NULL) {
		/* could assert message is non-empty */
		TALLOC_FREE(mem_ctx);
		return 0;
	}

	ok = conditional_ace_encode_binary(mem_ctx, s1, &e1);
	if (! ok) {
		abort();
	}

	s2 = parse_conditional_ace(mem_ctx, e1);
	if (s2 == NULL) {
		abort();
	}

	ok = conditional_ace_encode_binary(mem_ctx, s2, &e2);
	if (! ok) {
		abort();
	}
	if (data_blob_cmp(&e1, &e2) != 0) {
		abort();
	}

	/*
	 * We know now the SDDL representation compiles to a valid structure
	 * that survives a round trip through serialisation.
	 *
	 * A remaining question is whether it can be re-rendered as SDDL that
	 * compiles to the same blob.
	 */
	resddl = sddl_from_conditional_ace(mem_ctx, s2);
	if (resddl == NULL) {
		abort();
	}

	s2 = ace_conditions_compile_sddl(mem_ctx,
					 ACE_CONDITION_FLAG_ALLOW_DEVICE,
					 resddl,
					 &message,
					 &message_offset,
					 &length);
	if (s2 == NULL) {
		abort();
	}

	ok = conditional_ace_encode_binary(mem_ctx, s2, &e3);
	if (! ok) {
		abort();
	}
	if (data_blob_cmp(&e1, &e3) != 0) {
		abort();
	}

	TALLOC_FREE(mem_ctx);
	return 0;
}