ossfuzz: moving towards the ideal integration

- Start with the basic code from the ossfuzz project.
- Rewrite fuzz corpora to be binary files full of Type-Length-Value
  data, and write a glue layer in the fuzzing function to convert
  corpora into CURL options.
- Have supporting functions to generate corpora from existing tests
- Integrate with Makefile.am

19 files changed, 767 insertions, 162 deletions

diff --git a/.travis.yml b/.travis.yml
index c5505075a..cd8876e86 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -60,6 +60,10 @@ matrix:
           compiler: gcc
           dist: trusty
           env: T=distcheck
+        - os: linux
+          compiler: clang
+          dist: trusty
+          env: T=fuzzer
 
 install:
   - pip install --user cpp-coveralls
@@ -138,6 +142,16 @@ script:
              cmake .. && \
              make)
         fi
+    - |
+        if [ "$T" = "fuzzer" ]; then
+          export CC=clang
+          export CFLAGS="-fsanitize=address"
+          ./configure --disable-shared --enable-debug --enable-maintainer-mode
+          make
+          cd tests/fuzz
+          make clean
+          make check
+        fi
 
 # whitelist branches to avoid testing feature branches twice (as branch and as pull request)
 branches:
diff --git a/Makefile.am b/Makefile.am
index ab8f11cbc..e517ba56e 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -210,6 +210,9 @@ test-am:
 
 endif
 
+fuzzer:
+	@(cd tests/fuzz; $(MAKE) all)
+
 examples:
 	@(cd docs/examples; $(MAKE) check)
 
diff --git a/configure.ac b/configure.ac
index 1bfb28b1b..04d92d8f4 100755
--- a/configure.ac
+++ b/configure.ac
@@ -1873,7 +1873,7 @@ if test -z "$ssl_backends" -o "x$OPT_GNUTLS" != xno; then
           dnl linker doesn't search through, we need to add it to
           dnl LD_LIBRARY_PATH to prevent further configure tests to fail
           dnl due to this
-          if test "x$cross_compiling" != "xyes"; then 
+          if test "x$cross_compiling" != "xyes"; then
             LD_LIBRARY_PATH="$LD_LIBRARY_PATH:$gtlslib"
             export LD_LIBRARY_PATH
             AC_MSG_NOTICE([Added $gtlslib to LD_LIBRARY_PATH])
diff --git a/tests/curl_test_data.py b/tests/curl_test_data.py
index bfe1287d8..21747407d 100755
--- a/tests/curl_test_data.py
+++ b/tests/curl_test_data.py
@@ -24,12 +24,15 @@
 from __future__ import (absolute_import, division, print_function,
                         unicode_literals)
 import os
-import xml.etree.ElementTree as ET
+import re
 import logging
 
 log = logging.getLogger(__name__)
 
 
+REPLY_DATA = re.compile("<reply>\s*<data>(.*?)</data>", re.MULTILINE | re.DOTALL)
+
+
 class TestData(object):
     def __init__(self, data_folder):
         self.data_folder = data_folder
@@ -39,15 +42,17 @@ class TestData(object):
         filename = os.path.join(self.data_folder,
                                 "test{0}".format(test_number))
 
-        # The user should handle the exception from failing to find the file.
-        tree = ET.parse(filename)
+        log.debug("Parsing file %s", filename)
+
+        with open(filename, "rb") as f:
+            contents = f.read().decode("utf-8")
 
-        # We need the <reply><data> text.
-        reply = tree.find("reply")
-        data = reply.find("data")
+        m = REPLY_DATA.search(contents)
+        if not m:
+            raise Exception("Couldn't find a <reply><data> section")
 
-        # Return the text contents of the data
-        return data.text
+        # Left-strip the data so we don't get a newline before our data.
+        return m.group(1).lstrip()
 
 
 if __name__ == '__main__':
diff --git a/tests/fuzz/CMakeLists.txt b/tests/fuzz/CMakeLists.txt
deleted file mode 100644
index aefedf26f..000000000
--- a/tests/fuzz/CMakeLists.txt
+++ /dev/null
@@ -1 +0,0 @@
-# FIXME, probably adapt from file in ../unit
diff --git a/tests/fuzz/Makefile.am b/tests/fuzz/Makefile.am
index 7a245dda5..270b9783e 100644
--- a/tests/fuzz/Makefile.am
+++ b/tests/fuzz/Makefile.am
@@ -30,18 +30,21 @@ AUTOMAKE_OPTIONS = foreign nostdinc
 # $(top_builddir)/lib is for libcurl's generated lib/curl_config.h file
 # $(top_srcdir)/lib for libcurl's lib/curl_setup.h and other "borrowed" files
 
-AM_CPPFLAGS = -I$(top_srcdir)/include        \
-              -I$(top_builddir)/lib          \
-              -I$(top_srcdir)/lib            \
-              -I$(top_srcdir)/tests/fuzz
+AM_CFLAGS = -I$(top_srcdir)/include        \
+            -I$(top_builddir)/lib          \
+            -I$(top_srcdir)/lib            \
+            -I$(top_srcdir)/tests/fuzz
 
-EXTRA_DIST = Makefile.inc CMakeLists.txt
+LIBS = -lpthread -lstdc++ -lm
 
-LIBS = -lpthread -lFuzzer -lstdc++ -lm
-LDFLAGS = -L/usr/lib/llvm-5.0/lib
+# Run e.g. "make all LIB_FUZZING_ENGINE=/path/to/libFuzzer.a"
+# to link the fuzzer(s) against a real fuzzing engine.
+#
+# OSS-Fuzz will define its own value for LIB_FUZZING_ENGINE.
+LIB_FUZZING_ENGINE ?= libstandaloneengine.a
 
 LDADD = $(top_builddir)/lib/libcurl.la      \
-        @LDFLAGS@ @LIBCURL_LIBS@
+        $(LIB_FUZZING_ENGINE) @LDFLAGS@ @LIBCURL_LIBS@
 
 # Makefile.inc provides neat definitions
 include Makefile.inc
@@ -50,4 +53,4 @@ checksrc:
 	@PERL@ $(top_srcdir)/lib/checksrc.pl $(srcdir)/*.c
 
 noinst_PROGRAMS = $(FUZZPROGS)
-
+noinst_LIBRARIES = $(FUZZLIBS)
\ No newline at end of file
diff --git a/tests/fuzz/Makefile.inc b/tests/fuzz/Makefile.inc
index fb6cdb11a..4d475374b 100644
--- a/tests/fuzz/Makefile.inc
+++ b/tests/fuzz/Makefile.inc
@@ -1,19 +1,15 @@
-FUZZPROGS = http11 ftp imap pop3 httpupload http2
+FUZZPROGS = curl_fuzzer
+FUZZLIBS = libstandaloneengine.a
 
-http11_SOURCES = curl_fuzzer.c
-http11_CPPFLAGS = $(AM_CPPFLAGS)
+curl_fuzzer_SOURCES = curl_fuzzer.c
+curl_fuzzer_CFLAGS = $(AM_CFLAGS)
 
-ftp_SOURCES = curl_fuzzer.c
-ftp_CPPFLAGS = -DFUZZER_FTP $(AM_CPPFLAGS)
+libstandaloneengine_a_SOURCES = standalone_fuzz_target_runner.c
+libstandaloneengine_a_CFLAGS = $(AM_CFLAGS)
 
-imap_SOURCES = curl_fuzzer.c
-imap_CPPFLAGS = -DFUZZER_IMAP $(AM_CPPFLAGS)
+# Some more targets.
+zip:
+	zip -q -r curl_fuzzer_seed_corpus.zip curl_fuzz_data
 
-pop3_SOURCES = curl_fuzzer.c
-pop3_CPPFLAGS = -DFUZZER_POP3 $(AM_CPPFLAGS)
-
-httpupload_SOURCES = curl_fuzzer.c
-httpupload_CPPFLAGS = -DFUZZER_HTTP_UPLOAD $(AM_CPPFLAGS)
-
-http2_SOURCES = curl_fuzzer.c
-http2_CPPFLAGS = -DFUZZER_HTTP2 $(AM_CPPFLAGS)
+check: all
+	./curl_fuzzer curl_fuzz_data/*
\ No newline at end of file
diff --git a/tests/fuzz/README b/tests/fuzz/README
index 459bda46b..cdb69fe82 100644
--- a/tests/fuzz/README
+++ b/tests/fuzz/README
@@ -2,13 +2,18 @@ Fuzz tests
 ==========
 
 The goal is to add tests for *ALL* protocols supported in libcurl.
-We will need some additional patches in the future, to increase coverage.
 
 Building the fuzz target
 ========================
+From the CURL root directory:
 
-CC=clang-5.0 CFLAGS="-fsanitize=address -fsanitize-address-use-after-scope -fsanitize-coverage=trace-pc-guard,trace-cmp" ./configure --disable-shared --enable-debug --enable-maintainer-mode
+export CC=clang-5.0
+export CFLAGS="-fsanitize=address -fsanitize-address-use-after-scope -fsanitize-coverage=trace-pc-guard,trace-cmp"
+./configure --disable-shared --enable-debug --enable-maintainer-mode
 make -sj
 
 cd tests/fuzz
-make
+
+(optional) export LIB_FUZZING_ENGINE=<path to libFuzzer.a>
+
+make check
diff --git a/tests/fuzz/corpora/ftp/long1.txt b/tests/fuzz/corpora/ftp/long1.txt
deleted file mode 100644
index 47a536e38..000000000
--- a/tests/fuzz/corpora/ftp/long1.txt
+++ /dev/null
@@ -1,8 +0,0 @@
-200 OK
-200 OK
-215 UNIX Type: L8
-200 OK
-200 OK
-200 OK
-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
-220 OK
diff --git a/tests/fuzz/corpora/http1_1/200_ok.txt b/tests/fuzz/corpora/http1_1/200_ok.txt
deleted file mode 100644
index ca7ef0b23..000000000
--- a/tests/fuzz/corpora/http1_1/200_ok.txt
+++ /dev/null
@@ -1,13 +0,0 @@
-HTTP/1.1 200 OK

-Content-Encoding: gzip

-Accept-Ranges: bytes

-Cache-Control: max-age=604800

-Content-Type: text/html

-Date: Mon, 08 May 2017 19:03:58 GMT

-Etag: "359670651+gzip"

-Expires: Mon, 15 May 2017 19:03:58 GMT

-Last-Modified: Fri, 09 Aug 2013 23:54:35 GMT

-Server: ECS (ewr/15BD)

-X-Cache: HIT

-Content-Length: 606

-

diff --git a/tests/fuzz/corpora/http1_1/404_nf.txt b/tests/fuzz/corpora/http1_1/404_nf.txt
deleted file mode 100644
index a28311a35..000000000
--- a/tests/fuzz/corpora/http1_1/404_nf.txt
+++ /dev/null
@@ -1,9 +0,0 @@
-HTTP/1.1 404 Not Found

-Cache-Control: max-age=604800

-Content-Type: text/html

-Date: Mon, 08 May 2017 19:04:08 GMT

-Expires: Mon, 15 May 2017 19:04:08 GMT

-Server: EOS (lax004/28A3)

-Vary: Accept-Encoding

-Content-Length: 1270

-

diff --git a/tests/fuzz/curl_fuzz_data/test1 b/tests/fuzz/curl_fuzz_data/test1
new file mode 100644
index 000000000..f7b734a9c
--- /dev/null
+++ b/tests/fuzz/curl_fuzz_data/test1
diff --git a/tests/fuzz/curl_fuzz_data/test2 b/tests/fuzz/curl_fuzz_data/test2
new file mode 100644
index 000000000..8b44d6719
--- /dev/null
+++ b/tests/fuzz/curl_fuzz_data/test2
diff --git a/tests/fuzz/curl_fuzz_data/test3 b/tests/fuzz/curl_fuzz_data/test3
new file mode 100644
index 000000000..81c6670aa
--- /dev/null
+++ b/tests/fuzz/curl_fuzz_data/test3
diff --git a/tests/fuzz/curl_fuzzer.c b/tests/fuzz/curl_fuzzer.c
index 2ccf1b36e..f4a4ec6f9 100644
--- a/tests/fuzz/curl_fuzzer.c
+++ b/tests/fuzz/curl_fuzzer.c
@@ -1,128 +1,340 @@
-/*
-# Copyright 2016 Google Inc.
-#
-# 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
-#
-#      https://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-#
-################################################################################
-*/
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 2017, Max Dymond, <cmeister2@gmail.com>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
 
-#include <errno.h>
-#include <fcntl.h>
-#include <netinet/in.h>
-#include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <sys/select.h>
-#include <sys/socket.h>
-#include <sys/stat.h>
-#include <sys/time.h>
-#include <sys/types.h>
 #include <unistd.h>
-
 #include <curl/curl.h>
+#include "curl_fuzzer.h"
+
+/**
+ * Fuzzing entry point. This function is passed a buffer containing a test
+ * case.  This test case should drive the CURL API into making a request.
+ */
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
+{
+  int rc = 0;
+  int tlv_rc;
+  FUZZ_DATA fuzz;
+  TLV tlv;
+
+  if(size < sizeof(TLV_RAW)) {
+    /* Not enough data */
+    goto EXIT_LABEL;
+  }
 
-static const void *cur_data;
-static int cur_size = -1;
-static int server_fd = -1;
-static int client_fd = -1;
-static int wrote = 0;
+  /* Try to initialize the fuzz data */
+  FTRY(fuzz_initialize_fuzz_data(&fuzz, data, size));
+
+  for(tlv_rc = fuzz_get_first_tlv(&fuzz, &tlv);
+      tlv_rc == 0;
+      tlv_rc = fuzz_get_next_tlv(&fuzz, &tlv)) {
+    /* Have the TLV in hand. Parse the TLV. */
+    fuzz_parse_tlv(&fuzz, &tlv);
+  }
+
+  if(tlv_rc != TLV_RC_NO_MORE_TLVS) {
+    /* A TLV call failed. Can't continue. */
+    goto EXIT_LABEL;
+  }
+
+  /* Do the CURL stuff! */
+  curl_easy_perform(fuzz.easy);
+
+EXIT_LABEL:
+
+  fuzz_terminate_fuzz_data(&fuzz);
+
+  /* This function must always return 0. Non-zero codes are reserved. */
+  return 0;
+}
+
+/**
+ * Utility function to convert 4 bytes to a u32 predictably.
+ */
+uint32_t to_u32(uint8_t b[4])
+{
+  uint32_t u;
+  u = (b[0] << 24) + (b[1] << 16) + (b[2] << 8) + b[3];
+  return u;
+}
 
-static void fail(const char *why) {
-  perror(why);
-  exit(1);
+/**
+ * Utility function to convert 2 bytes to a u16 predictably.
+ */
+uint16_t to_u16(uint8_t b[2])
+{
+  uint16_t u;
+  u = (b[0] << 8) + b[1];
+  return u;
 }
 
-static curl_socket_t open_sock(void *ctx, curlsocktype purpose,
-                               struct curl_sockaddr *address) {
-  if(cur_size == -1) {
-    fail("not fuzzing");
+/**
+ * Initialize the local fuzz data structure.
+ */
+int fuzz_initialize_fuzz_data(FUZZ_DATA *fuzz,
+                              const uint8_t *data,
+                              size_t data_len)
+{
+  int rc = 0;
+
+  /* Initialize the fuzz data. */
+  memset(fuzz, 0, sizeof(FUZZ_DATA));
+
+  /* Create an easy handle. This will have all of the settings configured on
+     it. */
+  fuzz->easy = curl_easy_init();
+  FCHECK(fuzz->easy != NULL);
+
+  /* Set some standard options on the CURL easy handle. We need to override the
+     socket function so that we create our own sockets to present to CURL. */
+  FTRY(curl_easy_setopt(fuzz->easy,
+                        CURLOPT_OPENSOCKETFUNCTION,
+                        fuzz_open_socket));
+  FTRY(curl_easy_setopt(fuzz->easy, CURLOPT_OPENSOCKETDATA, fuzz));
+
+  /* In case something tries to set a socket option, intercept this. */
+  FTRY(curl_easy_setopt(fuzz->easy,
+                        CURLOPT_SOCKOPTFUNCTION,
+                        fuzz_sockopt_callback));
+
+  /* Can enable verbose mode */
+  /* FTRY(curl_easy_setopt(fuzz->easy, CURLOPT_VERBOSE, 1L)); */
+
+  /* Set up the state parser */
+  fuzz->state.data = data;
+  fuzz->state.data_len = data_len;
+
+EXIT_LABEL:
+
+  return rc;
+}
+
+/**
+ * Terminate the fuzz data structure, including freeing any allocated memory.
+ */
+void fuzz_terminate_fuzz_data(FUZZ_DATA *fuzz)
+{
+  fuzz_free((void **)&fuzz->url);
+  fuzz_free((void **)&fuzz->username);
+  fuzz_free((void **)&fuzz->password);
+  fuzz_free((void **)&fuzz->postfields);
+
+  if(fuzz->easy != NULL) {
+    curl_easy_cleanup(fuzz->easy);
+    fuzz->easy = NULL;
   }
-  if(server_fd != -1 || client_fd != -1) {
-    fail("already connected");
+}
+
+/**
+ * If a pointer has been allocated, free that pointer.
+ */
+void fuzz_free(void **ptr)
+{
+  if(*ptr != NULL) {
+    free(*ptr);
+    *ptr = NULL;
   }
+}
+
+/**
+ * Function for providing a socket to CURL already primed with data.
+ */
+static curl_socket_t fuzz_open_socket(void *ptr,
+                                      curlsocktype purpose,
+                                      struct curl_sockaddr *address)
+{
+  FUZZ_DATA *fuzz = (FUZZ_DATA *)ptr;
   int fds[2];
+  curl_socket_t server_fd;
+  curl_socket_t client_fd;
+
+  /* Handle unused parameters */
+  (void)purpose;
+  (void)address;
+
   if(socketpair(AF_UNIX, SOCK_STREAM, 0, fds)) {
-    fail("socketpair");
+    /* Failed to create a pair of sockets. */
+    return CURL_SOCKET_BAD;
   }
+
   server_fd = fds[0];
   client_fd = fds[1];
-  if(write(server_fd, cur_data, cur_size) != cur_size) {
-    fail("write");
+
+  /* Try and write the response data to the server file descriptor so the
+     client can read it. */
+  if(write(server_fd,
+           fuzz->rsp1_data,
+           fuzz->rsp1_data_len) != (ssize_t)fuzz->rsp1_data_len) {
+    /* Failed to write the data. */
+    return CURL_SOCKET_BAD;
   }
+
   if(shutdown(server_fd, SHUT_WR)) {
-    fail("shutdown");
+    return CURL_SOCKET_BAD;
   }
+
   return client_fd;
 }
 
-static int set_opt(void *ctx, curl_socket_t curlfd, curlsocktype purpose) {
+/**
+ * Callback function for setting socket options on the sockets created by
+ * fuzz_open_socket. In our testbed the sockets are "already connected".
+ */
+static int fuzz_sockopt_callback(void *ptr,
+                                 curl_socket_t curlfd,
+                                 curlsocktype purpose)
+{
+  (void)ptr;
+  (void)curlfd;
+  (void)purpose;
+
   return CURL_SOCKOPT_ALREADY_CONNECTED;
 }
 
-static size_t write_callback(char *ptr, size_t size, size_t n, void *ctx) {
-  return size * n;
+/**
+ * TLV access function - gets the first TLV from a data stream.
+ */
+int fuzz_get_first_tlv(FUZZ_DATA *fuzz,
+                       TLV *tlv)
+{
+  /* Reset the cursor. */
+  fuzz->state.data_pos = 0;
+  return fuzz_get_tlv_comn(fuzz, tlv);
 }
 
-static size_t read_callback(char *buf, size_t size, size_t n, void *ctx) {
-  if(wrote || size * n == 0) {
-    return 0;
+/**
+ * TLV access function - gets the next TLV from a data stream.
+*/
+int fuzz_get_next_tlv(FUZZ_DATA *fuzz,
+                      TLV *tlv)
+{
+  /* Advance the cursor by the full length of the previous TLV. */
+  fuzz->state.data_pos += sizeof(TLV_RAW) + tlv->length;
+
+  /* Work out if there's a TLV's worth of data to read */
+  if(fuzz->state.data_pos + sizeof(TLV_RAW) > fuzz->state.data_len) {
+    /* No more TLVs to parse */
+    return TLV_RC_NO_MORE_TLVS;
   }
-  wrote = 1;
-  buf[0] = 'a';
-  return 1;
+
+  return fuzz_get_tlv_comn(fuzz, tlv);
 }
 
-int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
-  cur_data = Data;
-  cur_size = Size;
-  wrote = 0;
-  CURL *curl = curl_easy_init();
-  curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_callback);
-  curl_easy_setopt(curl, CURLOPT_READFUNCTION, read_callback);
-  curl_easy_setopt(curl, CURLOPT_OPENSOCKETFUNCTION, open_sock);
-  curl_easy_setopt(curl, CURLOPT_SOCKOPTFUNCTION, set_opt);
-#if defined(FUZZER_FTP)
-  curl_easy_setopt(curl, CURLOPT_URL, "ftp://user@localhost/file.txt");
-#elif defined(FUZZER_IMAP)
-  curl_easy_setopt(curl, CURLOPT_USERNAME, "user");
-  curl_easy_setopt(curl, CURLOPT_PASSWORD, "secret");
-  curl_easy_setopt(curl, CURLOPT_URL, "imap://localhost");
-#elif defined(FUZZER_POP3)
-  curl_easy_setopt(curl, CURLOPT_USERNAME, "user");
-  curl_easy_setopt(curl, CURLOPT_PASSWORD, "secret");
-  curl_easy_setopt(curl, CURLOPT_URL, "pop3://localhost");
-#elif defined(FUZZER_HTTP_UPLOAD)
-  curl_easy_setopt(curl, CURLOPT_URL, "http://localhost/");
-  curl_easy_setopt(curl, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);
-  curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
-#elif defined(FUZZER_HTTP2)
-  curl_easy_setopt(curl, CURLOPT_URL, "http://localhost/");
-  /* use non-TLS HTTP/2 without HTTP/1.1 Upgrade: */
-  curl_easy_setopt(curl, CURLOPT_HTTP_VERSION,
-                   CURL_HTTP_VERSION_2_PRIOR_KNOWLEDGE);
-#else
-  curl_easy_setopt(curl, CURLOPT_URL, "http://localhost/");
-  curl_easy_setopt(curl, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);
-#endif
-  curl_easy_perform(curl);
-  curl_easy_cleanup(curl);
-  close(server_fd);
-  close(client_fd);
-  server_fd = -1;
-  client_fd = -1;
-  cur_data = NULL;
-  cur_size = -1;
-  return 0;
+/**
+ * Common TLV function for accessing TLVs in a data stream.
+ */
+int fuzz_get_tlv_comn(FUZZ_DATA *fuzz,
+                      TLV *tlv)
+{
+  int rc = 0;
+  size_t data_offset;
+  TLV_RAW *raw;
+
+  /* Start by casting the data stream to a TLV. */
+  raw = (TLV_RAW *)&fuzz->state.data[fuzz->state.data_pos];
+  data_offset = fuzz->state.data_pos + sizeof(TLV_RAW);
+
+  /* Set the TLV values. */
+  tlv->type = to_u16(raw->raw_type);
+  tlv->length = to_u32(raw->raw_length);
+  tlv->value = &fuzz->state.data[data_offset];
+
+  /* Sanity check that the TLV length is ok. */
+  if(data_offset + tlv->length > fuzz->state.data_len) {
+    rc = TLV_RC_SIZE_ERROR;
+  }
+
+  return rc;
+}
+
+/**
+ * Do different actions on the CURL handle for different received TLVs.
+ */
+int fuzz_parse_tlv(FUZZ_DATA *fuzz, TLV *tlv)
+{
+  int rc;
+
+  switch(tlv->type) {
+    case TLV_TYPE_URL:
+      FCHECK(fuzz->url == NULL);
+      fuzz->url = fuzz_tlv_to_string(tlv);
+      FTRY(curl_easy_setopt(fuzz->easy, CURLOPT_URL, fuzz->url));
+      break;
+
+    case TLV_TYPE_RESPONSE1:
+      /* The pointers in the TLV will always be valid as long as the fuzz data
+         is in scope, which is the entirety of this file. */
+      fuzz->rsp1_data = tlv->value;
+      fuzz->rsp1_data_len = tlv->length;
+      break;
+
+    case TLV_TYPE_USERNAME:
+      FCHECK(fuzz->username == NULL);
+      fuzz->username = fuzz_tlv_to_string(tlv);
+      FTRY(curl_easy_setopt(fuzz->easy, CURLOPT_USERNAME, fuzz->username));
+      break;
+
+    case TLV_TYPE_PASSWORD:
+      FCHECK(fuzz->password == NULL);
+      fuzz->password = fuzz_tlv_to_string(tlv);
+      FTRY(curl_easy_setopt(fuzz->easy, CURLOPT_PASSWORD, fuzz->password));
+      break;
+
+    case TLV_TYPE_POSTFIELDS:
+      FCHECK(fuzz->postfields == NULL);
+      fuzz->postfields = fuzz_tlv_to_string(tlv);
+      FTRY(curl_easy_setopt(fuzz->easy, CURLOPT_POSTFIELDS, fuzz->postfields));
+      break;
+
+    default:
+      /* The fuzzer generates lots of unknown TLVs, so don't do anything if
+         the TLV isn't known. */
+      break;
+  }
+
+  rc = 0;
+
+EXIT_LABEL:
+
+  return rc;
+}
+
+/**
+ * Converts a TLV data and length into an allocated string.
+ */
+char *fuzz_tlv_to_string(TLV *tlv)
+{
+  char *tlvstr;
+
+  /* Allocate enough space, plus a null terminator */
+  tlvstr = malloc(tlv->length + 1);
+
+  if(tlvstr != NULL) {
+    memcpy(tlvstr, tlv->value, tlv->length);
+    tlvstr[tlv->length] = 0;
+  }
+
+  return tlvstr;
 }
diff --git a/tests/fuzz/curl_fuzzer.h b/tests/fuzz/curl_fuzzer.h
new file mode 100644
index 000000000..a0c9d596a
--- /dev/null
+++ b/tests/fuzz/curl_fuzzer.h
@@ -0,0 +1,148 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 2017, Max Dymond, <cmeister2@gmail.com>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#include <curl/curl.h>
+
+/**
+ * TLV types.
+ */
+#define TLV_TYPE_URL                    1
+#define TLV_TYPE_RESPONSE1              2
+#define TLV_TYPE_USERNAME               3
+#define TLV_TYPE_PASSWORD               4
+#define TLV_TYPE_POSTFIELDS             5
+
+/**
+ * TLV function return codes.
+ */
+#define TLV_RC_NO_ERROR                 0
+#define TLV_RC_NO_MORE_TLVS             1
+#define TLV_RC_SIZE_ERROR               2
+
+/**
+ * Byte stream representation of the TLV header. Casting the byte stream
+ * to a TLV_RAW allows us to examine the type and length.
+ */
+typedef struct tlv_raw
+{
+  /* Type of the TLV - 16 bits. */
+  uint8_t raw_type[2];
+
+  /* Length of the TLV data - 32 bits. */
+  uint8_t raw_length[4];
+
+} TLV_RAW;
+
+typedef struct tlv
+{
+  /* Type of the TLV */
+  uint16_t type;
+
+  /* Length of the TLV data */
+  uint32_t length;
+
+  /* Pointer to data if length > 0. */
+  const uint8_t *value;
+
+} TLV;
+
+/**
+ * Internal state when parsing a TLV data stream.
+ */
+typedef struct fuzz_parse_state
+{
+  /* Data stream */
+  const uint8_t *data;
+  size_t data_len;
+
+  /* Current position of our "cursor" in processing the data stream. */
+  size_t data_pos;
+
+} FUZZ_PARSE_STATE;
+
+/**
+ * Data local to a fuzzing run.
+ */
+typedef struct fuzz_data
+{
+  /* CURL easy object */
+  CURL *easy;
+
+  /* Parser state */
+  FUZZ_PARSE_STATE state;
+
+  /* Current URL. */
+  char *url;
+
+  /* Response data and length */
+  const uint8_t *rsp1_data;
+  size_t rsp1_data_len;
+
+  /* Username and password */
+  char *username;
+  char *password;
+
+  /* Postfields */
+  char *postfields;
+
+} FUZZ_DATA;
+
+/* Function prototypes */
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size);
+uint32_t to_u32(uint8_t b[4]);
+uint16_t to_u16(uint8_t b[2]);
+int fuzz_initialize_fuzz_data(FUZZ_DATA *fuzz,
+                              const uint8_t *data,
+                              size_t data_len);
+void fuzz_terminate_fuzz_data(FUZZ_DATA *fuzz);
+void fuzz_free(void **ptr);
+static curl_socket_t fuzz_open_socket(void *ptr,
+                                      curlsocktype purpose,
+                                      struct curl_sockaddr *address);
+static int fuzz_sockopt_callback(void *ptr,
+                                 curl_socket_t curlfd,
+                                 curlsocktype purpose);
+int fuzz_get_first_tlv(FUZZ_DATA *fuzz, TLV *tlv);
+int fuzz_get_next_tlv(FUZZ_DATA *fuzz, TLV *tlv);
+int fuzz_get_tlv_comn(FUZZ_DATA *fuzz, TLV *tlv);
+int fuzz_parse_tlv(FUZZ_DATA *fuzz, TLV *tlv);
+char *fuzz_tlv_to_string(TLV *tlv);
+
+/* Macros */
+#define FTRY(FUNC)                                                             \
+        {                                                                      \
+          int _func_rc = (FUNC);                                               \
+          if (_func_rc)                                                        \
+          {                                                                    \
+            rc = _func_rc;                                                     \
+            goto EXIT_LABEL;                                                   \
+          }                                                                    \
+        }
+
+#define FCHECK(COND)                                                           \
+        {                                                                      \
+          if (!(COND))                                                         \
+          {                                                                    \
+            rc = 1;                                                            \
+            goto EXIT_LABEL;                                                   \
+          }                                                                    \
+        }
diff --git a/tests/fuzz/generate_corpus.py b/tests/fuzz/generate_corpus.py
new file mode 100755
index 000000000..0bb2eda3c
--- /dev/null
+++ b/tests/fuzz/generate_corpus.py
@@ -0,0 +1,138 @@
+#!/usr/bin/env python
+#
+# Simple script which generates corpus files.
+
+import argparse
+import logging
+import struct
+import sys
+sys.path.append("..")
+import curl_test_data
+log = logging.getLogger(__name__)
+
+
+def generate_corpus(options):
+    td = curl_test_data.TestData("../data")
+
+    with open(options.output, "wb") as f:
+        enc = TLVEncoder(f)
+
+        # Write the URL to the file.
+        enc.write_string(enc.TYPE_URL, options.url)
+
+        # Write the first response to the file.
+        if options.rsp1:
+            enc.write_bytes(enc.TYPE_RSP1, options.rsp1.encode("utf-8"))
+
+        elif options.rsp1file:
+            with open(options.rsp1file, "rb") as g:
+                enc.write_bytes(enc.TYPE_RSP1, g.read())
+
+        elif options.rsp1test:
+            wstring = td.get_test_data(options.rsp1test)
+            enc.write_bytes(enc.TYPE_RSP1, wstring.encode("utf-8"))
+
+        # Write other options to file.
+        enc.maybe_write_string(enc.TYPE_USERNAME, options.username)
+        enc.maybe_write_string(enc.TYPE_PASSWORD, options.password)
+        enc.maybe_write_string(enc.TYPE_POSTFIELDS, options.postfields)
+
+    return ScriptRC.SUCCESS
+
+
+class TLVEncoder(object):
+    TYPE_URL = 1
+    TYPE_RSP1 = 2
+    TYPE_USERNAME = 3
+    TYPE_PASSWORD = 4
+    TYPE_POSTFIELDS = 5
+
+    def __init__(self, output):
+        self.output = output
+
+    def write_string(self, tlv_type, wstring):
+        data = wstring.encode("utf-8")
+        self.write_tlv(tlv_type, len(data), data)
+
+    def write_bytes(self, tlv_type, bytedata):
+        self.write_tlv(tlv_type, len(bytedata), bytedata)
+
+    def maybe_write_string(self, tlv_type, wstring):
+        if wstring:
+            self.write_string(tlv_type, wstring)
+
+    def write_tlv(self, tlv_type, tlv_length, tlv_data=None):
+        log.debug("Writing TLV %d, length %d, data %r",
+                  tlv_type,
+                  tlv_length,
+                  tlv_data)
+
+        data = struct.pack("!H", tlv_type)
+        self.output.write(data)
+
+        data = struct.pack("!L", tlv_length)
+        self.output.write(data)
+
+        if tlv_data:
+            self.output.write(tlv_data)
+
+
+def get_options():
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--output", required=True)
+    parser.add_argument("--url", required=True)
+    parser.add_argument("--username")
+    parser.add_argument("--password")
+    parser.add_argument("--postfields")
+
+    rsp1 = parser.add_mutually_exclusive_group(required=True)
+    rsp1.add_argument("--rsp1")
+    rsp1.add_argument("--rsp1file")
+    rsp1.add_argument("--rsp1test", type=int)
+
+    return parser.parse_args()
+
+
+def setup_logging():
+    """
+    Set up logging from the command line options
+    """
+    root_logger = logging.getLogger()
+    formatter = logging.Formatter("%(asctime)s %(levelname)-5.5s %(message)s")
+    stdout_handler = logging.StreamHandler(sys.stdout)
+    stdout_handler.setFormatter(formatter)
+    stdout_handler.setLevel(logging.DEBUG)
+    root_logger.addHandler(stdout_handler)
+    root_logger.setLevel(logging.DEBUG)
+
+
+class ScriptRC(object):
+    """Enum for script return codes"""
+    SUCCESS = 0
+    FAILURE = 1
+    EXCEPTION = 2
+
+
+class ScriptException(Exception):
+    pass
+
+
+def main():
+    # Get the options from the user.
+    options = get_options()
+
+    setup_logging()
+
+    # Run main script.
+    try:
+        rc = generate_corpus(options)
+    except Exception as e:
+        log.exception(e)
+        rc = ScriptRC.EXCEPTION
+
+    log.info("Returning %d", rc)
+    return rc
+
+
+if __name__ == '__main__':
+    sys.exit(main())
diff --git a/tests/fuzz/standalone_fuzz_target_runner.c b/tests/fuzz/standalone_fuzz_target_runner.c
new file mode 100644
index 000000000..c131a2192
--- /dev/null
+++ b/tests/fuzz/standalone_fuzz_target_runner.c
@@ -0,0 +1,89 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 2017, Max Dymond, <cmeister2@gmail.com>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "standalone_fuzz_target_runner.h"
+
+/**
+ * Main procedure for standalone fuzzing engine.
+ *
+ * Reads filenames from the argument array. For each filename, read the file
+ * into memory and then call the fuzzing interface with the data.
+ */
+int main(int argc, char **argv)
+{
+  int ii;
+  FILE *infile;
+  uint8_t *buffer = NULL;
+  size_t buffer_len;
+
+  for(ii = 1; ii < argc; ii++) {
+    /* Try and open the file. */
+    infile = fopen(argv[ii], "rb");
+    if(infile) {
+      printf("[%s] Open succeeded! \n", argv[ii]);
+
+      /* Get the length of the file. */
+      fseek(infile, 0L, SEEK_END);
+      buffer_len = ftell(infile);
+
+      /* Reset the file indicator to the beginning of the file. */
+      fseek(infile, 0L, SEEK_SET);
+
+      /* Allocate a buffer for the file contents. */
+      buffer = (uint8_t *)calloc(buffer_len, sizeof(uint8_t));
+      if(buffer) {
+        /* Read all the text from the file into the buffer. */
+        fread(buffer, sizeof(uint8_t), buffer_len, infile);
+        printf("[%s] Read %zu bytes, calling fuzzer\n", argv[ii], buffer_len);
+
+        /* Call the fuzzer with the data. */
+        LLVMFuzzerTestOneInput(buffer, buffer_len);
+
+        printf("[%s] Fuzzing complete\n", argv[ii]);
+
+        /* Free the buffer as it's no longer needed. */
+        free(buffer);
+        buffer = NULL;
+      }
+      else
+      {
+        fprintf(stderr,
+                "[%s] Failed to allocate %zu bytes \n",
+                argv[ii],
+                buffer_len);
+      }
+
+      /* Close the file as it's no longer needed. */
+      fclose(infile);
+      infile = NULL;
+    }
+    else
+    {
+      /* Failed to open the file. Maybe wrong name or wrong permissions? */
+      fprintf(stderr, "[%s] Open failed. \n", argv[ii]);
+    }
+  }
+}
diff --git a/tests/fuzz/standalone_fuzz_target_runner.h b/tests/fuzz/standalone_fuzz_target_runner.h
new file mode 100644
index 000000000..37302618b
--- /dev/null
+++ b/tests/fuzz/standalone_fuzz_target_runner.h
@@ -0,0 +1,23 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 2017, Max Dymond, <cmeister2@gmail.com>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size);
\ No newline at end of file