oss-fuzz/projects/zlib/example_small_fuzzer.c

119 lines
2.9 KiB
C

#include <stdio.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include <assert.h>
#include <stdlib.h>
#include <inttypes.h>
#include "zlib.h"
#define CHECK_ERR(err, msg) { \
if (err != Z_OK) { \
fprintf(stderr, "%s error: %d\n", msg, err); \
exit(1); \
} \
}
static const uint8_t *data;
static size_t dataLen;
static alloc_func zalloc = NULL;
static free_func zfree = NULL;
/* ===========================================================================
* Test deflate() with small buffers
*/
void test_deflate(unsigned char *compr, size_t comprLen) {
z_stream c_stream; /* compression stream */
int err;
unsigned long len = dataLen;
c_stream.zalloc = zalloc;
c_stream.zfree = zfree;
c_stream.opaque = (void *)0;
err = deflateInit(&c_stream, Z_DEFAULT_COMPRESSION);
CHECK_ERR(err, "deflateInit");
c_stream.next_in = (Bytef *)data;
c_stream.next_out = compr;
while (c_stream.total_in != len && c_stream.total_out < comprLen) {
c_stream.avail_in = c_stream.avail_out = 1; /* force small buffers */
err = deflate(&c_stream, Z_NO_FLUSH);
CHECK_ERR(err, "deflate small 1");
}
/* Finish the stream, still forcing small buffers: */
for (;;) {
c_stream.avail_out = 1;
err = deflate(&c_stream, Z_FINISH);
if (err == Z_STREAM_END)
break;
CHECK_ERR(err, "deflate small 2");
}
err = deflateEnd(&c_stream);
CHECK_ERR(err, "deflateEnd");
}
/* ===========================================================================
* Test inflate() with small buffers
*/
void test_inflate(unsigned char *compr, size_t comprLen, unsigned char *uncompr,
size_t uncomprLen) {
int err;
z_stream d_stream; /* decompression stream */
d_stream.zalloc = zalloc;
d_stream.zfree = zfree;
d_stream.opaque = (void *)0;
d_stream.next_in = compr;
d_stream.avail_in = 0;
d_stream.next_out = uncompr;
err = inflateInit(&d_stream);
CHECK_ERR(err, "inflateInit");
while (d_stream.total_out < uncomprLen && d_stream.total_in < comprLen) {
d_stream.avail_in = d_stream.avail_out = 1; /* force small buffers */
err = inflate(&d_stream, Z_NO_FLUSH);
if (err == Z_STREAM_END)
break;
CHECK_ERR(err, "inflate");
}
err = inflateEnd(&d_stream);
CHECK_ERR(err, "inflateEnd");
if (memcmp(uncompr, data, dataLen)) {
fprintf(stderr, "bad inflate\n");
exit(1);
}
}
int LLVMFuzzerTestOneInput(const uint8_t *d, size_t size) {
size_t comprLen = compressBound(size);
size_t uncomprLen = size;
uint8_t *compr, *uncompr;
/* Discard inputs larger than 1Mb. */
static size_t kMaxSize = 1024 * 1024;
if (size < 1 || size > kMaxSize)
return 0;
data = d;
dataLen = size;
compr = (uint8_t *)calloc(1, comprLen);
uncompr = (uint8_t *)calloc(1, uncomprLen);
test_deflate(compr, comprLen);
test_inflate(compr, comprLen, uncompr, uncomprLen);
free(compr);
free(uncompr);
/* This function must return 0. */
return 0;
}