fuzz/corpus2array.c

/*
 * Copyright (C) 2019-2021 Free Software Foundation, Inc.
 *
 * This file is part of LIBTASN1.
 *
 * The LIBTASN1 library is free software; you can redistribute it
 * and/or modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA
 */

/*
 Helper tool to convert a corpus from libtasn1_array2tree_fuzzer into a asn1_static_node C code.

 Example usage:
   $ cat libtasn1_array2tree_fuzzer.in/e04b8bc97fcf0d6386dfa44e32b1700e42e0eb64 | ./corpus2array
   const asn1_static_node tab[] = {
     { "999=999", CONST_UNIVERSAL|CONST_IMPLICIT|CONST_SET|CONST_ASSIGN|CONST_DOWN, "993\xff~\xff$y\xd9\x80" },
     { NULL, 0, NULL }
   };   cat leak-d69d42ff01f6c3acca35dee27538a99e6821fced | ./corpus2array
 */

#include <stdio.h>
#include <string.h>
#include <ctype.h>

struct fuzz_elem {
	unsigned int type;
	char name[20];
	char value[20];
};

static char *escape(unsigned char *s)
{
	static char out[19 * 6 + 1];
	char *p = out;

	while (*s) {
		if (*s > 127) {
			if (isxdigit(s[1])) {
				sprintf(p, "\\u%04x", *s++);
				p += 6;
			} else {
				sprintf(p, "\\x%02x", *s++);
				p += 4;
			}
		} else if (*s == '\n') {
			sprintf(p, "\\n");
			p += 2;
			s++;
		} else if (*s == '\t') {
			sprintf(p, "\\t");
			p += 2;
			s++;
		} else
			*p++ = *s++;
	}
	*p = 0;

	return out;
}

static const char *typename[24] = {
  "CONST_UNIVERSAL",
  "CONST_PRIVATE",
  "CONST_APPLICATION",
  "CONST_EXPLICIT",
  "CONST_IMPLICIT",
  "CONST_TAG",
  "CONST_OPTION",
  "CONST_DEFAULT",
  "CONST_TRUE",
  "CONST_FALSE",
  "CONST_LIST",
  "CONST_MIN_MAX",
  "CONST_1_PARAM",
  "CONST_SIZE",
  "CONST_DEFINED_BY",
  "CONST_GENERALIZED",
  "CONST_UTC",
  NULL, /* #define CONST_IMPORTS     (1<<25) */
  "CONST_NOT_USED",
  "CONST_SET",
  "CONST_ASSIGN",
  "CONST_DOWN",
  "CONST_RIGHT",
  NULL
};

int main(void)
{
	struct fuzz_elem e;

	printf("const asn1_static_node tab[] = {\n");

	while (fread(&e, sizeof(e), 1, stdin) == 1) {
		e.name[sizeof(e.name) - 1] = 0;
		e.value[sizeof(e.value) - 1] = 0;
		if (strcmp(e.name, "NULL"))
			printf("  { \"%s\"", escape((unsigned char *) e.name));
		else
			printf("  { NULL");

		if (e.type) {
			int add = 0;

			// we leave the lowest 8 bit out
			if ((e.type & 0xFF) == 17) {
				printf(", ASN1_ETYPE_TIME");
				add = 1;
			}

			for (int i = 8; i < 32 ; i++) {
				if ((e.type & (1U << i)) && typename[i - 8]) {
					printf(add ? "|%s" : ", %s", typename[i - 8]);
					add = 1;
				}
			}

			if (!add)
				printf(", %u", e.type);
		} else
			printf(", 0");

		if (strcmp(e.value, "NULL"))
			printf(", \"%s\" },\n", escape((unsigned char *) e.value));
		else
			printf(", NULL },");
	}

	printf("  { NULL, 0, NULL }\n");
	printf("};\n");

	return 0;
}