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-rw-r--r--utils/libtokencap/Makefile94
-rw-r--r--utils/libtokencap/README.md69
-rw-r--r--utils/libtokencap/libtokencap.so.c794
3 files changed, 957 insertions, 0 deletions
diff --git a/utils/libtokencap/Makefile b/utils/libtokencap/Makefile
new file mode 100644
index 00000000..b81e1729
--- /dev/null
+++ b/utils/libtokencap/Makefile
@@ -0,0 +1,94 @@
+#
+# american fuzzy lop++ - libtokencap
+# --------------------------------
+#
+# Originally written by Michal Zalewski
+#
+# Copyright 2016 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+
+PREFIX      ?= /usr/local
+HELPER_PATH  = $(PREFIX)/lib/afl
+DOC_PATH    ?= $(PREFIX)/share/doc/afl
+MAN_PATH    ?= $(PREFIX)/share/man/man8
+
+VERSION     = $(shell grep '^\#define VERSION ' ../../config.h | cut -d '"' -f2)
+
+CFLAGS      ?= -O3 -funroll-loops -D_FORTIFY_SOURCE=2
+override CFLAGS += -I ../../include/ -Wall -g -Wno-pointer-sign
+
+
+UNAME_S =$(shell uname -s)# GNU make
+UNAME_S:sh=uname -s       # BSD make
+_UNIQ=_QINU_
+
+    _OS_DL = $(_UNIQ)$(UNAME_S)
+   __OS_DL =     $(_OS_DL:$(_UNIQ)Linux=$(_UNIQ))
+  ___OS_DL =    $(__OS_DL:$(_UNIQ)Darwin=$(_UNIQ))
+ ____OS_DL =   $(___OS_DL:$(_UNIQ)$(UNAME_S)=)
+_____OS_DL =  $(____OS_DL:$(_UNIQ)="-ldl")
+
+     _OS_TARGET = $(___OS_DL:$(_UNIQ)FreeBSD=$(_UNIQ))
+    __OS_TARGET =     $(_OS_TARGET:$(_UNIQ)OpenBSD=$(_UNIQ))
+   ___OS_TARGET =    $(__OS_TARGET:$(_UNIQ)NetBSD=$(_UNIQ))
+  ____OS_TARGET =   $(___OS_TARGET:$(_UNIQ)Haiku=$(_UNIQ))
+ _____OS_TARGET =  $(____OS_TARGET:$(_UNIQ)SunOS=$(_UNIQ))
+______OS_TARGET = $(_____OS_TARGET:$(_UNIQ)$(UNAME_S)=)
+
+TARGETS       =  $(______OS_TARGET:$(_UNIQ)=libtokencap.so)
+
+LDFLAGS     += $(_____OS_DL)
+
+#ifeq "$(shell uname)" "Linux"
+#  TARGETS = libtokencap.so
+#  LDFLAGS     += -ldl
+#endif
+#ifeq "$(shell uname)" "Darwin"
+#  TARGETS = libtokencap.so
+#  LDFLAGS     += -ldl
+#endif
+#ifeq "$(shell uname)" "FreeBSD"
+#  TARGETS = libtokencap.so
+#endif
+#ifeq "$(shell uname)" "OpenBSD"
+#  TARGETS = libtokencap.so
+#endif
+#ifeq "$(shell uname)" "NetBSD"
+#  TARGETS = libtokencap.so
+#endif
+#ifeq "$(shell uname)" "DragonFly"
+#  TARGETS = libtokencap.so
+#  LDFLAGS     += -ldl
+#endif
+all: $(TARGETS)
+
+libtokencap.so: libtokencap.so.c ../../config.h
+	$(CC) $(CFLAGS) $(CPPFLAGS) -shared -fPIC $< -o $@ $(LDFLAGS)
+	cp -f libtokencap.so ../../
+
+.NOTPARALLEL: clean
+
+debug:
+	@echo $(UNAME_S)$(_UNIQ) | hexdump -C
+	@echo from $(____OS_DL) : $(_UNIQ)$(UNAME_S) = -\> $(_____OS_DL)
+	@echo from $(_____OS_DL) : $(_UNIQ) = -ldl -\> $(______OS_DL)
+	@echo from $(____OS_DL) : $(_UNIQ)FreeBSD = $(_UNIQ) -\> $(_OS_TARGET)
+	@echo from $(_OS_TARGET) : $(_UNIQ)OpenBSD = $(_UNIQ) -\> $(__OS_TARGET)
+	@echo from $(__OS_TARGET) : $(_UNIQ)NetBSD = $(_UNIQ) -\> $(___OS_TARGET)
+	@echo from $(___OS_TARGET) : $(_UNIQ)$(_UNIQ) = -\> $(____OS_TARGET)
+	@echo from $(____OS_TARGET) : $(_UNIQ) = libtokencap.so -\> $(TARGETS)
+
+clean:
+	rm -f *.o *.so *~ a.out core core.[1-9][0-9]*
+	rm -fv ../../libtokencap.so
+
+install: all
+	install -m 755 -d $${DESTDIR}$(HELPER_PATH)
+	install -m 755 ../../libtokencap.so $${DESTDIR}$(HELPER_PATH)
+	install -m 644 -T README.md $${DESTDIR}$(DOC_PATH)/README.tokencap.md
diff --git a/utils/libtokencap/README.md b/utils/libtokencap/README.md
new file mode 100644
index 00000000..a39ed3a5
--- /dev/null
+++ b/utils/libtokencap/README.md
@@ -0,0 +1,69 @@
+# strcmp() / memcmp() token capture library
+
+ NOTE: libtokencap is only recommended for binary-only targets or targets that
+ do not compile with afl-clang-fast/afl-clang-lto.
+ The afl-clang-fast AFL_LLVM_DICT2FILE feature is much better, afl-clang-lto
+ has that feature automatically integrated.
+
+  (See ../../README.md for the general instruction manual.)
+
+This companion library allows you to instrument `strcmp()`, `memcmp()`,
+and related functions to automatically extract syntax tokens passed to any of
+these libcalls. The resulting list of tokens may be then given as a starting
+dictionary to afl-fuzz (the -x option) to improve coverage on subsequent
+fuzzing runs.
+
+This may help improving coverage in some targets, and do precisely nothing in
+others. In some cases, it may even make things worse: if libtokencap picks up
+syntax tokens that are not used to process the input data, but that are a part
+of - say - parsing a config file... well, you're going to end up wasting a lot
+of CPU time on trying them out in the input stream. In other words, use this
+feature with care. Manually screening the resulting dictionary is almost
+always a necessity.
+
+As for the actual operation: the library stores tokens, without any deduping,
+by appending them to a file specified via AFL_TOKEN_FILE. If the variable is not
+set, the tool uses stderr (which is probably not what you want).
+
+Similarly to afl-tmin, the library is not "proprietary" and can be used with
+other fuzzers or testing tools without the need for any code tweaks. It does not
+require AFL-instrumented binaries to work.
+
+To use the library, you *need* to make sure that your fuzzing target is compiled
+with -fno-builtin and is linked dynamically. If you wish to automate the first
+part without mucking with CFLAGS in Makefiles, you can set AFL_NO_BUILTIN=1
+when using afl-gcc. This setting specifically adds the following flags:
+
+```
+  -fno-builtin-strcmp -fno-builtin-strncmp -fno-builtin-strcasecmp
+  -fno-builtin-strcasencmp -fno-builtin-memcmp -fno-builtin-strstr
+  -fno-builtin-strcasestr
+```
+
+The next step is simply loading this library via LD_PRELOAD. The optimal usage
+pattern is to allow afl-fuzz to fuzz normally for a while and build up a corpus,
+and then fire off the target binary, with libtokencap.so loaded, on every file
+found by AFL in that earlier run. This demonstrates the basic principle:
+
+```
+  export AFL_TOKEN_FILE=$PWD/temp_output.txt
+
+  for i in <out_dir>/queue/id*; do
+    LD_PRELOAD=/path/to/libtokencap.so \
+      /path/to/target/program [...params, including $i...]
+  done
+
+  sort -u temp_output.txt >afl_dictionary.txt
+```
+
+If you don't get any results, the target library is probably not using strcmp()
+and memcmp() to parse input; or you haven't compiled it with -fno-builtin; or
+the whole thing isn't dynamically linked, and LD_PRELOAD is having no effect.
+
+Portability hints: There is probably no particularly portable and non-invasive
+way to distinguish between read-only and read-write memory mappings.
+The `__tokencap_load_mappings()` function is the only thing that would
+need to be changed for other OSes.
+
+Current supported OSes are: Linux, Darwin, FreeBSD (thanks to @devnexen)
+
diff --git a/utils/libtokencap/libtokencap.so.c b/utils/libtokencap/libtokencap.so.c
new file mode 100644
index 00000000..3629e804
--- /dev/null
+++ b/utils/libtokencap/libtokencap.so.c
@@ -0,0 +1,794 @@
+/*
+
+   american fuzzy lop++ - extract tokens passed to strcmp / memcmp
+   -------------------------------------------------------------
+
+   Originally written by Michal Zalewski
+
+   Copyright 2016 Google Inc. All rights reserved.
+   Copyright 2019-2020 AFLplusplus Project. All rights reserved.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at:
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+   This Linux-only companion library allows you to instrument strcmp(),
+   memcmp(), and related functions to automatically extract tokens.
+   See README.tokencap.md for more info.
+
+ */
+
+#ifndef _GNU_SOURCE
+  #define _GNU_SOURCE
+#endif
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdbool.h>
+
+#include "../types.h"
+#include "../config.h"
+
+#if !defined __linux__ && !defined __APPLE__ && !defined __FreeBSD__ &&      \
+    !defined __OpenBSD__ && !defined __NetBSD__ && !defined __DragonFly__ && \
+    !defined(__HAIKU__) && !defined(__sun)
+  #error "Sorry, this library is unsupported in this platform for now!"
+#endif /* !__linux__ && !__APPLE__ && ! __FreeBSD__ && ! __OpenBSD__ && \
+          !__NetBSD__*/
+
+#if defined __APPLE__
+  #include <mach/vm_map.h>
+  #include <mach/mach_init.h>
+#elif defined __FreeBSD__ || defined __OpenBSD__ || defined __NetBSD__
+  #include <sys/types.h>
+  #include <sys/sysctl.h>
+  #if !defined __NetBSD__
+    #include <sys/user.h>
+  #endif
+  #include <sys/mman.h>
+#elif defined __HAIKU__
+  #include <kernel/image.h>
+#elif defined __sun
+  /* For map addresses the old struct is enough */
+  #include <sys/procfs.h>
+  #include <limits.h>
+#endif
+
+#include <dlfcn.h>
+
+#ifdef RTLD_NEXT
+/* The libc functions are a magnitude faster than our replacements.
+   Use them when RTLD_NEXT is available. */
+int (*__libc_strcmp)(const char *str1, const char *str2);
+int (*__libc_strncmp)(const char *str1, const char *str2, size_t len);
+int (*__libc_strcasecmp)(const char *str1, const char *str2);
+int (*__libc_strncasecmp)(const char *str1, const char *str2, size_t len);
+int (*__libc_memcmp)(const void *mem1, const void *mem2, size_t len);
+int (*__libc_bcmp)(const void *mem1, const void *mem2, size_t len);
+char *(*__libc_strstr)(const char *haystack, const char *needle);
+char *(*__libc_strcasestr)(const char *haystack, const char *needle);
+void *(*__libc_memmem)(const void *haystack, size_t haystack_len,
+                       const void *needle, size_t needle_len);
+#endif
+
+/* Mapping data and such */
+
+#define MAX_MAPPINGS 1024
+
+static struct mapping { void *st, *en; } __tokencap_ro[MAX_MAPPINGS];
+
+static u32   __tokencap_ro_cnt;
+static u8    __tokencap_ro_loaded;
+static int   __tokencap_out_file = -1;
+static pid_t __tokencap_pid = -1;
+
+/* Identify read-only regions in memory. Only parameters that fall into these
+   ranges are worth dumping when passed to strcmp() and so on. Read-write
+   regions are far more likely to contain user input instead. */
+
+static void __tokencap_load_mappings(void) {
+
+#if defined __linux__
+
+  u8    buf[MAX_LINE];
+  FILE *f = fopen("/proc/self/maps", "r");
+
+  __tokencap_ro_loaded = 1;
+
+  if (!f) return;
+
+  while (fgets(buf, MAX_LINE, f)) {
+
+    u8    rf, wf;
+    void *st, *en;
+
+    if (sscanf(buf, "%p-%p %c%c", &st, &en, &rf, &wf) != 4) continue;
+    if (wf == 'w' || rf != 'r') continue;
+
+    __tokencap_ro[__tokencap_ro_cnt].st = (void *)st;
+    __tokencap_ro[__tokencap_ro_cnt].en = (void *)en;
+
+    if (++__tokencap_ro_cnt == MAX_MAPPINGS) break;
+
+  }
+
+  fclose(f);
+
+#elif defined __APPLE__
+
+  struct vm_region_submap_info_64 region;
+  mach_msg_type_number_t          cnt = VM_REGION_SUBMAP_INFO_COUNT_64;
+  vm_address_t                    base = 0;
+  vm_size_t                       size = 0;
+  natural_t                       depth = 0;
+
+  __tokencap_ro_loaded = 1;
+
+  while (1) {
+
+    if (vm_region_recurse_64(mach_task_self(), &base, &size, &depth,
+                             (vm_region_info_64_t)&region,
+                             &cnt) != KERN_SUCCESS)
+      break;
+
+    if (region.is_submap) {
+
+      depth++;
+
+    } else {
+
+      /* We only care of main map addresses and the read only kinds */
+      if ((region.protection & VM_PROT_READ) &&
+          !(region.protection & VM_PROT_WRITE)) {
+
+        __tokencap_ro[__tokencap_ro_cnt].st = (void *)base;
+        __tokencap_ro[__tokencap_ro_cnt].en = (void *)(base + size);
+
+        if (++__tokencap_ro_cnt == MAX_MAPPINGS) break;
+
+      }
+
+      base += size;
+      size = 0;
+
+    }
+
+  }
+
+#elif defined __FreeBSD__ || defined __OpenBSD__ || defined __NetBSD__
+
+  #if defined   __FreeBSD__
+  int    mib[] = {CTL_KERN, KERN_PROC, KERN_PROC_VMMAP, __tokencap_pid};
+  #elif defined __OpenBSD__
+  int mib[] = {CTL_KERN, KERN_PROC_VMMAP, __tokencap_pid};
+  #elif defined __NetBSD__
+  int mib[] = {CTL_VM, VM_PROC, VM_PROC_MAP, __tokencap_pid,
+               sizeof(struct kinfo_vmentry)};
+  #endif
+  char * buf, *low, *high;
+  size_t miblen = sizeof(mib) / sizeof(mib[0]);
+  size_t len;
+
+  if (sysctl(mib, miblen, NULL, &len, NULL, 0) == -1) return;
+
+  #if defined __FreeBSD__ || defined __NetBSD__
+  len = len * 4 / 3;
+  #elif defined                      __OpenBSD__
+  len -= len % sizeof(struct kinfo_vmentry);
+  #endif
+
+  buf = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0);
+  if (buf == MAP_FAILED) return;
+
+  if (sysctl(mib, miblen, buf, &len, NULL, 0) == -1) {
+
+    munmap(buf, len);
+    return;
+
+  }
+
+  low = buf;
+  high = low + len;
+
+  __tokencap_ro_loaded = 1;
+
+  while (low < high) {
+
+    struct kinfo_vmentry *region = (struct kinfo_vmentry *)low;
+
+  #if defined __FreeBSD__ || defined __NetBSD__
+
+    #if defined   __FreeBSD__
+    size_t                size = region->kve_structsize;
+
+    if (size == 0) break;
+    #elif defined __NetBSD__
+    size_t size = sizeof(*region);
+    #endif
+
+    /* We go through the whole mapping of the process and track read-only
+     * addresses */
+    if ((region->kve_protection & KVME_PROT_READ) &&
+        !(region->kve_protection & KVME_PROT_WRITE)) {
+
+  #elif defined __OpenBSD__
+
+    size_t size = sizeof(*region);
+
+    /* We go through the whole mapping of the process and track read-only
+     * addresses */
+    if ((region->kve_protection & KVE_PROT_READ) &&
+        !(region->kve_protection & KVE_PROT_WRITE)) {
+
+  #endif
+      __tokencap_ro[__tokencap_ro_cnt].st = (void *)region->kve_start;
+      __tokencap_ro[__tokencap_ro_cnt].en = (void *)region->kve_end;
+
+      if (++__tokencap_ro_cnt == MAX_MAPPINGS) break;
+
+    }
+
+    low += size;
+
+  }
+
+  munmap(buf, len);
+#elif defined __HAIKU__
+  image_info ii;
+  int32_t    group = 0;
+
+  __tokencap_ro_loaded = 1;
+
+  while (get_next_image_info(0, &group, &ii) == B_OK) {
+
+    __tokencap_ro[__tokencap_ro_cnt].st = ii.text;
+    __tokencap_ro[__tokencap_ro_cnt].en = ((char *)ii.text) + ii.text_size;
+
+    if (++__tokencap_ro_cnt == MAX_MAPPINGS) break;
+
+  }
+
+#elif defined __sun
+  prmap_t *c, *map;
+  char     path[PATH_MAX];
+  ssize_t  r;
+  size_t   hint;
+  int      fd;
+
+  snprintf(path, sizeof(path), "/proc/%ld/map", getpid());
+  fd = open(path, O_RDONLY);
+  hint = (1 << 20);
+  map = malloc(hint);
+
+  __tokencap_ro_loaded = 1;
+
+  for (; (r = pread(fd, map, hint, 0)) == hint;) {
+
+    hint <<= 1;
+    map = realloc(map, hint);
+
+  }
+
+  for (c = map; r > 0; c++, r -= sizeof(prmap_t)) {
+
+    __tokencap_ro[__tokencap_ro_cnt].st = (void *)c->pr_vaddr;
+    __tokencap_ro[__tokencap_ro_cnt].en = (void *)(c->pr_vaddr + c->pr_size);
+
+    if (++__tokencap_ro_cnt == MAX_MAPPINGS) break;
+
+  }
+
+  free(map);
+  close(fd);
+#endif
+
+}
+
+/* Check an address against the list of read-only mappings. */
+
+static u8 __tokencap_is_ro(const void *ptr) {
+
+  u32 i;
+
+  if (!__tokencap_ro_loaded) __tokencap_load_mappings();
+
+  for (i = 0; i < __tokencap_ro_cnt; i++)
+    if (ptr >= __tokencap_ro[i].st && ptr <= __tokencap_ro[i].en) return 1;
+
+  return 0;
+
+}
+
+/* Dump an interesting token to output file, quoting and escaping it
+   properly. */
+
+static void __tokencap_dump(const u8 *ptr, size_t len, u8 is_text) {
+
+  u8  buf[MAX_AUTO_EXTRA * 4 + 1];
+  u32 i;
+  u32 pos = 0;
+
+  if (len < MIN_AUTO_EXTRA || len > MAX_AUTO_EXTRA || __tokencap_out_file == -1)
+    return;
+
+  for (i = 0; i < len; i++) {
+
+    if (is_text && !ptr[i]) break;
+
+    switch (ptr[i]) {
+
+      case 0 ... 31:
+      case 127 ... 255:
+      case '\"':
+      case '\\':
+
+        sprintf(buf + pos, "\\x%02x", ptr[i]);
+        pos += 4;
+        break;
+
+      default:
+        buf[pos++] = ptr[i];
+
+    }
+
+  }
+
+  buf[pos] = 0;
+
+  int wrt_ok = (1 == write(__tokencap_out_file, "\"", 1));
+  wrt_ok &= (pos == write(__tokencap_out_file, buf, pos));
+  wrt_ok &= (2 == write(__tokencap_out_file, "\"\n", 2));
+
+}
+
+/* Replacements for strcmp(), memcmp(), and so on. Note that these will be used
+   only if the target is compiled with -fno-builtins and linked dynamically. */
+
+#undef strcmp
+
+int strcmp(const char *str1, const char *str2) {
+
+  if (__tokencap_is_ro(str1)) __tokencap_dump(str1, strlen(str1), 1);
+  if (__tokencap_is_ro(str2)) __tokencap_dump(str2, strlen(str2), 1);
+
+#ifdef RTLD_NEXT
+  if (__libc_strcmp) return __libc_strcmp(str1, str2);
+#endif
+
+  while (1) {
+
+    const unsigned char c1 = *str1, c2 = *str2;
+
+    if (c1 != c2) return (c1 > c2) ? 1 : -1;
+    if (!c1) return 0;
+    str1++;
+    str2++;
+
+  }
+
+}
+
+#undef strncmp
+
+int strncmp(const char *str1, const char *str2, size_t len) {
+
+  if (__tokencap_is_ro(str1)) __tokencap_dump(str1, len, 1);
+  if (__tokencap_is_ro(str2)) __tokencap_dump(str2, len, 1);
+
+#ifdef RTLD_NEXT
+  if (__libc_strncmp) return __libc_strncmp(str1, str2, len);
+#endif
+
+  while (len--) {
+
+    unsigned char c1 = *str1, c2 = *str2;
+
+    if (c1 != c2) return (c1 > c2) ? 1 : -1;
+    if (!c1) return 0;
+    str1++;
+    str2++;
+
+  }
+
+  return 0;
+
+}
+
+#undef strcasecmp
+
+int strcasecmp(const char *str1, const char *str2) {
+
+  if (__tokencap_is_ro(str1)) __tokencap_dump(str1, strlen(str1), 1);
+  if (__tokencap_is_ro(str2)) __tokencap_dump(str2, strlen(str2), 1);
+
+#ifdef RTLD_NEXT
+  if (__libc_strcasecmp) return __libc_strcasecmp(str1, str2);
+#endif
+
+  while (1) {
+
+    const unsigned char c1 = tolower((int)*str1), c2 = tolower((int)*str2);
+
+    if (c1 != c2) return (c1 > c2) ? 1 : -1;
+    if (!c1) return 0;
+    str1++;
+    str2++;
+
+  }
+
+}
+
+#undef strncasecmp
+
+int strncasecmp(const char *str1, const char *str2, size_t len) {
+
+  if (__tokencap_is_ro(str1)) __tokencap_dump(str1, len, 1);
+  if (__tokencap_is_ro(str2)) __tokencap_dump(str2, len, 1);
+
+#ifdef RTLD_NEXT
+  if (__libc_strncasecmp) return __libc_strncasecmp(str1, str2, len);
+#endif
+
+  while (len--) {
+
+    const unsigned char c1 = tolower((int)*str1), c2 = tolower((int)*str2);
+
+    if (c1 != c2) return (c1 > c2) ? 1 : -1;
+    if (!c1) return 0;
+    str1++;
+    str2++;
+
+  }
+
+  return 0;
+
+}
+
+#undef memcmp
+
+int memcmp(const void *mem1, const void *mem2, size_t len) {
+
+  if (__tokencap_is_ro(mem1)) __tokencap_dump(mem1, len, 0);
+  if (__tokencap_is_ro(mem2)) __tokencap_dump(mem2, len, 0);
+
+#ifdef RTLD_NEXT
+  if (__libc_memcmp) return __libc_memcmp(mem1, mem2, len);
+#endif
+
+  const char *strmem1 = (const char *)mem1;
+  const char *strmem2 = (const char *)mem2;
+
+  while (len--) {
+
+    const unsigned char c1 = *strmem1, c2 = *strmem2;
+    if (c1 != c2) return (c1 > c2) ? 1 : -1;
+    strmem1++;
+    strmem2++;
+
+  }
+
+  return 0;
+
+}
+
+#undef bcmp
+
+int bcmp(const void *mem1, const void *mem2, size_t len) {
+
+  if (__tokencap_is_ro(mem1)) __tokencap_dump(mem1, len, 0);
+  if (__tokencap_is_ro(mem2)) __tokencap_dump(mem2, len, 0);
+
+#ifdef RTLD_NEXT
+  if (__libc_bcmp) return __libc_bcmp(mem1, mem2, len);
+#endif
+
+  const char *strmem1 = (const char *)mem1;
+  const char *strmem2 = (const char *)mem2;
+
+  while (len--) {
+
+    int diff = *strmem1 ^ *strmem2;
+    if (diff != 0) return 1;
+    strmem1++;
+    strmem2++;
+
+  }
+
+  return 0;
+
+}
+
+#undef strstr
+
+char *strstr(const char *haystack, const char *needle) {
+
+  if (__tokencap_is_ro(haystack))
+    __tokencap_dump(haystack, strlen(haystack), 1);
+
+  if (__tokencap_is_ro(needle)) __tokencap_dump(needle, strlen(needle), 1);
+
+#ifdef RTLD_NEXT
+  if (__libc_strstr) return __libc_strstr(haystack, needle);
+#endif
+
+  do {
+
+    const char *n = needle;
+    const char *h = haystack;
+
+    while (*n && *h && *n == *h)
+      n++, h++;
+
+    if (!*n) return (char *)haystack;
+
+  } while (*(haystack++));
+
+  return 0;
+
+}
+
+#undef strcasestr
+
+char *strcasestr(const char *haystack, const char *needle) {
+
+  if (__tokencap_is_ro(haystack))
+    __tokencap_dump(haystack, strlen(haystack), 1);
+
+  if (__tokencap_is_ro(needle)) __tokencap_dump(needle, strlen(needle), 1);
+
+#ifdef RTLD_NEXT
+  if (__libc_strcasestr) return __libc_strcasestr(haystack, needle);
+#endif
+
+  do {
+
+    const char *n = needle;
+    const char *h = haystack;
+
+    while (*n && *h && tolower((int)*n) == tolower((int)*h))
+      n++, h++;
+
+    if (!*n) return (char *)haystack;
+
+  } while (*(haystack++));
+
+  return 0;
+
+}
+
+#undef memmem
+
+void *memmem(const void *haystack, size_t haystack_len, const void *needle,
+             size_t needle_len) {
+
+  if (__tokencap_is_ro(haystack)) __tokencap_dump(haystack, haystack_len, 1);
+
+  if (__tokencap_is_ro(needle)) __tokencap_dump(needle, needle_len, 1);
+
+#ifdef RTLD_NEXT
+  if (__libc_memmem)
+    return __libc_memmem(haystack, haystack_len, needle, needle_len);
+#endif
+
+  const char *n = (const char *)needle;
+  const char *h = (const char *)haystack;
+  if (haystack_len < needle_len) return 0;
+  if (needle_len == 0) return (void *)haystack;
+  if (needle_len == 1) return memchr(haystack, *n, haystack_len);
+
+  const char *end = h + (haystack_len - needle_len);
+
+  do {
+
+    if (*h == *n) {
+
+      if (memcmp(h, n, needle_len) == 0) return (void *)h;
+
+    }
+
+  } while (h++ <= end);
+
+  return 0;
+
+}
+
+/* Common libraries wrappers (from honggfuzz) */
+
+/*
+ * Apache's httpd wrappers
+ */
+int ap_cstr_casecmp(const char *s1, const char *s2) {
+
+  return strcasecmp(s1, s2);
+
+}
+
+int ap_cstr_casecmpn(const char *s1, const char *s2, size_t n) {
+
+  return strncasecmp(s1, s2, n);
+
+}
+
+const char *ap_strcasestr(const char *s1, const char *s2) {
+
+  return strcasestr(s1, s2);
+
+}
+
+int apr_cstr_casecmp(const char *s1, const char *s2) {
+
+  return strcasecmp(s1, s2);
+
+}
+
+int apr_cstr_casecmpn(const char *s1, const char *s2, size_t n) {
+
+  return strncasecmp(s1, s2, n);
+
+}
+
+/*
+ * *SSL wrappers
+ */
+int CRYPTO_memcmp(const void *m1, const void *m2, size_t len) {
+
+  return memcmp(m1, m2, len);
+
+}
+
+int OPENSSL_memcmp(const void *m1, const void *m2, size_t len) {
+
+  return memcmp(m1, m2, len);
+
+}
+
+int OPENSSL_strcasecmp(const char *s1, const char *s2) {
+
+  return strcasecmp(s1, s2);
+
+}
+
+int OPENSSL_strncasecmp(const char *s1, const char *s2, size_t len) {
+
+  return strncasecmp(s1, s2, len);
+
+}
+
+int32_t memcmpct(const void *s1, const void *s2, size_t len) {
+
+  return memcmp(s1, s2, len);
+
+}
+
+/*
+ * libXML wrappers
+ */
+int xmlStrncmp(const char *s1, const char *s2, int len) {
+
+  if (len <= 0) { return 0; }
+  if (s1 == s2) { return 0; }
+  if (s1 == NULL) { return -1; }
+  if (s2 == NULL) { return 1; }
+  return strncmp(s1, s2, (size_t)len);
+
+}
+
+int xmlStrcmp(const char *s1, const char *s2) {
+
+  if (s1 == s2) { return 0; }
+  if (s1 == NULL) { return -1; }
+  if (s2 == NULL) { return 1; }
+  return strcmp(s1, s2);
+
+}
+
+int xmlStrEqual(const char *s1, const char *s2) {
+
+  if (s1 == s2) { return 1; }
+  if (s1 == NULL) { return 0; }
+  if (s2 == NULL) { return 0; }
+  if (strcmp(s1, s2) == 0) { return 1; }
+  return 0;
+
+}
+
+int xmlStrcasecmp(const char *s1, const char *s2) {
+
+  if (s1 == s2) { return 0; }
+  if (s1 == NULL) { return -1; }
+  if (s2 == NULL) { return 1; }
+  return strcasecmp(s1, s2);
+
+}
+
+int xmlStrncasecmp(const char *s1, const char *s2, int len) {
+
+  if (len <= 0) { return 0; }
+  if (s1 == s2) { return 0; }
+  if (s1 == NULL) { return -1; }
+  if (s2 == NULL) { return 1; }
+  return strncasecmp(s1, s2, (size_t)len);
+
+}
+
+const char *xmlStrstr(const char *haystack, const char *needle) {
+
+  if (haystack == NULL) { return NULL; }
+  if (needle == NULL) { return NULL; }
+  return strstr(haystack, needle);
+
+}
+
+const char *xmlStrcasestr(const char *haystack, const char *needle) {
+
+  if (haystack == NULL) { return NULL; }
+  if (needle == NULL) { return NULL; }
+  return strcasestr(haystack, needle);
+
+}
+
+/*
+ * Samba wrappers
+ */
+int memcmp_const_time(const void *s1, const void *s2, size_t n) {
+
+  return memcmp(s1, s2, n);
+
+}
+
+bool strcsequal(const void *s1, const void *s2) {
+
+  if (s1 == s2) { return true; }
+  if (!s1 || !s2) { return false; }
+  return (strcmp(s1, s2) == 0);
+
+}
+
+/* bcmp/memcmp BSD flavors, similar to CRYPTO_memcmp */
+
+int timingsafe_bcmp(const void *mem1, const void *mem2, size_t len) {
+
+  return bcmp(mem1, mem2, len);
+
+}
+
+int timingsafe_memcmp(const void *mem1, const void *mem2, size_t len) {
+
+  return memcmp(mem1, mem2, len);
+
+}
+
+/* Init code to open the output file (or default to stderr). */
+
+__attribute__((constructor)) void __tokencap_init(void) {
+
+  u8 *fn = getenv("AFL_TOKEN_FILE");
+  if (fn) __tokencap_out_file = open(fn, O_RDWR | O_CREAT | O_APPEND, 0655);
+  if (__tokencap_out_file == -1) __tokencap_out_file = STDERR_FILENO;
+  __tokencap_pid = getpid();
+
+#ifdef RTLD_NEXT
+  __libc_strcmp = dlsym(RTLD_NEXT, "strcmp");
+  __libc_strncmp = dlsym(RTLD_NEXT, "strncmp");
+  __libc_strcasecmp = dlsym(RTLD_NEXT, "strcasecmp");
+  __libc_strncasecmp = dlsym(RTLD_NEXT, "strncasecmp");
+  __libc_memcmp = dlsym(RTLD_NEXT, "memcmp");
+  __libc_bcmp = dlsym(RTLD_NEXT, "bcmp");
+  __libc_strstr = dlsym(RTLD_NEXT, "strstr");
+  __libc_strcasestr = dlsym(RTLD_NEXT, "strcasestr");
+  __libc_memmem = dlsym(RTLD_NEXT, "memmem");
+#endif
+
+}
+
+/* closing as best as we can the tokens file */
+__attribute__((destructor)) void __tokencap_shutdown(void) {
+
+  if (__tokencap_out_file != STDERR_FILENO) close(__tokencap_out_file);
+
+}
+