standalone mutator

custom_mutators/aflpp/standalone/Makefile

@@ -0,0 +1,10 @@
+
+CFLAGS = -O3 -funroll-loops -fPIC
+
+all: aflpp-standalone
+
+aflpp-standalone:	aflpp-standalone.c
+	$(CC) $(CFLAGS) -I../../../include -I. -o aflpp-standalone aflpp-standalone.c ../../../src/afl-performance.c
+
+clean:
+	rm -f *.o *~ aflpp-standalone core

custom_mutators/aflpp/standalone/README.md

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+# AFL++ standalone mutator
+
+this is the AFL++ havoc mutator as a standalone mutator
+
+just type `make` to build.
+
+```
+aflpp-standalone inputfile outputfile
+```
+

custom_mutators/aflpp/standalone/aflpp-standalone.c

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+#include "afl-mutations.h"
+
+s8  interesting_8[] = {INTERESTING_8};
+s16 interesting_16[] = {INTERESTING_8, INTERESTING_16};
+s32 interesting_32[] = {INTERESTING_8, INTERESTING_16, INTERESTING_32};
+
+typedef struct my_mutator {
+
+  afl_state_t *afl;
+  u8          *buf;
+  u32          buf_size;
+
+} my_mutator_t;
+
+my_mutator_t *afl_custom_init(afl_state_t *afl, unsigned int seed) {
+
+  (void)seed;
+
+  my_mutator_t *data = calloc(1, sizeof(my_mutator_t));
+  if (!data) {
+
+    perror("afl_custom_init alloc");
+    return NULL;
+
+  }
+
+  if ((data->buf = malloc(1024*1024)) == NULL) {
+
+    perror("afl_custom_init alloc");
+    return NULL;
+
+  } else {
+
+    data->buf_size = 1024*1024;
+
+  }
+
+  /* fake AFL++ state */
+  data->afl = calloc(1, sizeof(afl_state_t));
+  data->afl->queue_cycle = 1;
+  data->afl->fsrv.dev_urandom_fd = open("/dev/urandom", O_RDONLY);
+  rand_set_seed(data->afl, getpid());
+
+  return data;
+
+}
+
+/* here we run the AFL++ mutator, which is the best! */
+
+size_t afl_custom_fuzz(my_mutator_t *data, uint8_t *buf, size_t buf_size,
+                       u8 **out_buf, uint8_t *add_buf, size_t add_buf_size,
+                       size_t max_size) {
+
+  if (max_size > data->buf_size) {
+
+    u8 *ptr = realloc(data->buf, max_size);
+
+    if (ptr) {
+
+      return 0;
+
+    } else {
+
+      data->buf = ptr;
+      data->buf_size = max_size;
+
+    }
+
+  }
+
+  u32 havoc_steps = 1 + rand_below(data->afl, 16);
+
+  /* set everything up, costly ... :( */
+  memcpy(data->buf, buf, buf_size);
+
+  /* the mutation */
+  u32 out_buf_len = afl_mutate(data->afl, data->buf, buf_size, havoc_steps,
+                               false, true, add_buf, add_buf_size, max_size);
+
+  /* return size of mutated data */
+  *out_buf = data->buf;
+  return out_buf_len;
+
+}
+
+int main(int argc, char *argv[]) {
+
+  if (argc > 1 && strncmp(argv[1], "-h", 2) == 0) {
+  
+    printf("Syntax: $0 [-v] [inputfile [outputfile [splicefile]]]\n\n", argv[0]);
+    printf("Reads a testcase from stdin when no input file (or '-') is specified,\n");
+    printf("mutates according to AFL++'s mutation engine, and write to stdout when '-' or\n");
+    printf("no output filename is given. As an optional third parameter you can give a file\n");
+    printf("for splicing. Maximum input and output length is 1MB.\n");
+    printf("The -v verbose option prints debug output to stderr\n");
+    return 0;
+  
+  }
+
+  FILE *in = stdin, *out = stdout, *splice = NULL;
+  unsigned char *inbuf = malloc(1024 * 1024), *outbuf, *splicebuf = NULL;
+  int verbose = 0, splicelen = 0;
+
+  if (argc > 1 && strcmp(argv[1], "-v") == 0) {
+    verbose = 1;
+    argc--;
+    argv++;
+    fprintf(stderr, "Verbose active\n");
+  }
+
+  my_mutator_t *data = afl_custom_init(NULL, 0);
+
+  if (argc > 1 && strcmp(argv[1], "-") != 0) {
+    if ((in = fopen(argv[1], "r")) == NULL) {
+      perror(argv[1]);
+      return -1;
+    }
+    if (verbose) fprintf(stderr, "Input: %s\n", argv[1]);
+  }
+
+  size_t inlen = fread(inbuf, 1, 1024*1024, in);
+  
+  if (!inlen) {
+    fprintf(stderr, "Error: empty file %s\n", argv[1] ? argv[1] : "stdin");
+    return -1;
+  }
+
+  if (argc > 2 && strcmp(argv[2], "-") != 0) {
+    if ((out = fopen(argv[2], "w")) == NULL) {
+      perror(argv[2]);
+      return -1;
+    }
+    if (verbose) fprintf(stderr, "Output: %s\n", argv[2]);
+  }
+
+  if (argc > 3) {
+    if ((splice = fopen(argv[3], "r")) == NULL) {
+      perror(argv[3]);
+      return -1;
+    }
+    if (verbose) fprintf(stderr, "Splice: %s\n", argv[3]);
+    splicebuf = malloc(1024*1024);
+    size_t splicelen = fread(splicebuf, 1, 1024*1024, splice);
+    if (!splicelen) {
+      fprintf(stderr, "Error: empty file %s\n", argv[3]);
+      return -1;
+    }
+    if (verbose) fprintf(stderr, "Mutation splice length: %zu\n", splicelen);
+  }
+
+  if (verbose) fprintf(stderr, "Mutation input length: %zu\n", inlen);
+  unsigned int outlen = afl_custom_fuzz(data, inbuf, inlen, &outbuf, splicebuf, splicelen, 1024*1024);
+
+  if (outlen == 0 || !outbuf) {
+    fprintf(stderr, "Error: no mutation data returned.\n");
+    return -1;
+  }
+
+  if (verbose) fprintf(stderr, "Mutation output length: %zu\n", outlen);
+
+  if (fwrite(outbuf, 1, outlen, out) != outlen) {
+    fprintf(stderr, "Warning: incomplete write.\n");
+    return -1;
+  }
+  
+  return 0;
+}