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Add fuzzer support features.

This commit is contained in:
Philip.Hazel 2016-10-31 17:19:00 +00:00
parent 24ab24fde0
commit 2aa482039a
4 changed files with 307 additions and 3 deletions
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5
ChangeLog
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@ -112,6 +112,11 @@ only when PCRE2_NO_START_OPTIMIZE was *not* set:
16. The "offset" modifier in pcre2test was not being ignored (as documented)
when the POSIX API was in use.
17. Added --enable-fuzz-support to "configure", causing an non-installed
library containing a test function that can be called by fuzzers to be
compiled. A non-installed binary to run the test function locally, called
pcre2fuzzcheck is also compiled.
Version 10.22 29-July-2016
--------------------------

19
Makefile.am
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@ -2,7 +2,6 @@
AUTOMAKE_OPTIONS = subdir-objects
ACLOCAL_AMFLAGS = -I m4
AM_CPPFLAGS = -I$(builddir)/src -I$(srcdir)/src
## Specify the documentation files that are distributed.
@ -473,7 +472,7 @@ libpcre2_posix_la_CFLAGS += $(GCOV_CFLAGS)
endif # WITH_GCOV
endif # WITH_PCRE2_8
## Build pcre2grep if the 8-bit library is enabled
## Build pcre2grep and optional fuzzer stuff if the 8-bit library is enabled
if WITH_PCRE2_8
bin_PROGRAMS += pcre2grep
@ -485,6 +484,22 @@ if WITH_GCOV
pcre2grep_CFLAGS += $(GCOV_CFLAGS)
pcre2grep_LDADD += $(GCOV_LIBS)
endif # WITH_GCOV
## If fuzzer support is enabled, build a non-distributed library containing the
## fuzzing function. Also build the standalone checking binary from the same
## source but using -DSTANDALONE.
if WITH_FUZZ_SUPPORT
noinst_LIBRARIES = .libs/libpcre2-fuzzsupport.a
_libs_libpcre2_fuzzsupport_a_SOURCES = src/pcre2_fuzzsupport.c
_libs_libpcre2_fuzzsupport_a_CFLAGS = $(AM_CFLAGS)
_libs_libpcre2_fuzzsupport_a_LIBADD =
noinst_PROGRAMS += pcre2fuzzcheck
pcre2fuzzcheck_SOURCES = src/pcre2_fuzzsupport.c
pcre2fuzzcheck_CFLAGS = -DSTANDALONE $(AM_CFLAGS)
pcre2fuzzcheck_LDADD = libpcre2-8.la
endif # WITH FUZZ_SUPPORT
endif # WITH_PCRE2_8
## -------- Testing ----------

15
configure.ac
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@ -295,7 +295,7 @@ AC_ARG_WITH(match-limit-recursion,
# Handle --enable-valgrind
AC_ARG_ENABLE(valgrind,
AS_HELP_STRING([--enable-valgrind],
[valgrind support]),
[enable valgrind support]),
, enable_valgrind=no)
# Enable code coverage reports using gcov
@ -304,6 +304,12 @@ AC_ARG_ENABLE(coverage,
[enable code coverage reports using gcov]),
, enable_coverage=no)
# Handle --enable-fuzz-support
AC_ARG_ENABLE(fuzz_support,
AS_HELP_STRING([--enable-fuzz-support],
[enable fuzzer support]),
, enable_fuzz_support=no)
# Set the default value for pcre2-8
if test "x$enable_pcre2_8" = "xunset"
then
@ -420,6 +426,12 @@ AM_CONDITIONAL(WITH_REBUILD_CHARTABLES, test "x$enable_rebuild_chartables" = "xy
AM_CONDITIONAL(WITH_JIT, test "x$enable_jit" = "xyes")
AM_CONDITIONAL(WITH_UNICODE, test "x$enable_unicode" = "xyes")
AM_CONDITIONAL(WITH_VALGRIND, test "x$enable_valgrind" = "xyes")
AM_CONDITIONAL(WITH_FUZZ_SUPPORT, test "x$enable_fuzz_support" = "xyes")
if test "$enable_fuzz_support" = "yes" -a "$enable_pcre2_8" = "no"; then
echo "** ERROR: Fuzzer support requires the 8-bit library"
exit 1
fi
# Checks for typedefs, structures, and compiler characteristics.
@ -966,6 +978,7 @@ $PACKAGE-$VERSION configuration summary:
Link pcre2test with libreadline .... : ${enable_pcre2test_libreadline}
Valgrind support ................... : ${enable_valgrind}
Code coverage ...................... : ${enable_coverage}
Fuzzer support ..................... : ${enable_fuzz_support}
EOF

271
src/pcre2_fuzzsupport.c Normal file
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@ -0,0 +1,271 @@
/***************************************************************************
Fuzzer driver for PCRE2. Given an arbitrary string of bytes and a length, it
tries to compile and match it, deriving options from the string itself. If
STANDALONE is defined, a main program that calls the driver with the contents
of specified files is compiled, and commentary on what is happening is output.
If an argument starts with '=' the rest of it it is taken as a literal string
rather than a file name. This allows easy testing of short strings.
Written by Philip Hazel, October 2016
***************************************************************************/
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define PCRE2_CODE_UNIT_WIDTH 8
#include "pcre2.h"
#define ALLOWED_COMPILE_OPTIONS \
(PCRE2_ANCHORED|PCRE2_ALLOW_EMPTY_CLASS|PCRE2_ALT_BSUX|PCRE2_ALT_CIRCUMFLEX| \
PCRE2_ALT_VERBNAMES|PCRE2_AUTO_CALLOUT|PCRE2_CASELESS|PCRE2_DOLLAR_ENDONLY| \
PCRE2_DOTALL|PCRE2_DUPNAMES|PCRE2_EXTENDED|PCRE2_FIRSTLINE| \
PCRE2_MATCH_UNSET_BACKREF|PCRE2_MULTILINE|PCRE2_NEVER_BACKSLASH_C| \
PCRE2_NO_AUTO_CAPTURE| \
PCRE2_NO_AUTO_POSSESS|PCRE2_NO_DOTSTAR_ANCHOR|PCRE2_NO_START_OPTIMIZE| \
PCRE2_UCP|PCRE2_UNGREEDY|PCRE2_USE_OFFSET_LIMIT| \
PCRE2_UTF)
#define ALLOWED_MATCH_OPTIONS \
(PCRE2_ANCHORED|PCRE2_NOTBOL|PCRE2_NOTEOL|PCRE2_NOTEMPTY| \
PCRE2_NOTEMPTY_ATSTART|PCRE2_PARTIAL_HARD| \
PCRE2_PARTIAL_SOFT|PCRE2_NO_JIT)
/* Putting in this apparently unnecessary prototype prevents gcc from giving a
"no previous prototype" warning when compiling at high warning level. */
int LLVMFuzzerTestOneInput(const unsigned char *, size_t);
/* Here's the driving function. */
int LLVMFuzzerTestOneInput(const unsigned char *data, size_t size)
{
uint32_t compile_options;
uint32_t match_options;
pcre2_match_data *match_data = NULL;
int r1, r2;
int i;
if (size < 1) return 0;
/* Figure out some options to use. Initialize the random number to ensure
repeatability. Ensure that we get a 32-bit unsigned random number for testing
options. (RAND_MAX is required to be at least 32767, but is commonly
2147483647, which excludes the top bit.) */
srand((unsigned int)(data[size/2]));
r1 = rand();
r2 = rand();
/* Ensure that all undefined option bits are zero (waste of time trying them)
and also that PCRE2_NO_UTF_CHECK is unset, as there is no guarantee that the
input is UTF-8. Also unset PCRE2_NEVER_UTF and PCRE2_NEVER_UCP as there is no
reason to disallow UTF and UCP. Force PCRE2_NEVER_BACKSLASH_C to be set because
\C in random patterns is highly likely to cause a crash. */
compile_options =
((uint32_t)((r1 << 16) | (r2 & 0xffff)) & ALLOWED_COMPILE_OPTIONS) |
PCRE2_NEVER_BACKSLASH_C;
match_options =
((uint32_t)((r1 << 16) | (r2 & 0xffff)) & ALLOWED_MATCH_OPTIONS);
/* Do the compile with and without the options, and after a successful compile,
likewise do the match with and without the options. */
for (i = 0; i < 2; i++)
{
int errorcode;
PCRE2_SIZE erroroffset;
pcre2_code *code;
#ifdef STANDALONE
printf("Compile with options %.8x", compile_options);
printf("%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n",
((compile_options & PCRE2_ALT_BSUX) != 0)? ",alt_bsux" : "",
((compile_options & PCRE2_ALT_CIRCUMFLEX) != 0)? ",alt_circumflex" : "",
((compile_options & PCRE2_ALT_VERBNAMES) != 0)? ",alt_verbnames" : "",
((compile_options & PCRE2_ALLOW_EMPTY_CLASS) != 0)? ",allow_empty_class" : "",
((compile_options & PCRE2_ANCHORED) != 0)? ",anchored" : "",
((compile_options & PCRE2_AUTO_CALLOUT) != 0)? ",auto_callout" : "",
((compile_options & PCRE2_CASELESS) != 0)? ",caseless" : "",
((compile_options & PCRE2_DOLLAR_ENDONLY) != 0)? ",dollar_endonly" : "",
((compile_options & PCRE2_DOTALL) != 0)? ",dotall" : "",
((compile_options & PCRE2_DUPNAMES) != 0)? ",dupnames" : "",
((compile_options & PCRE2_EXTENDED) != 0)? ",extended" : "",
((compile_options & PCRE2_FIRSTLINE) != 0)? ",firstline" : "",
((compile_options & PCRE2_MATCH_UNSET_BACKREF) != 0)? ",match_unset_backref" : "",
((compile_options & PCRE2_MULTILINE) != 0)? ",multiline" : "",
((compile_options & PCRE2_NEVER_BACKSLASH_C) != 0)? ",never_backslash_c" : "",
((compile_options & PCRE2_NEVER_UCP) != 0)? ",never_ucp" : "",
((compile_options & PCRE2_NEVER_UTF) != 0)? ",never_utf" : "",
((compile_options & PCRE2_NO_AUTO_CAPTURE) != 0)? ",no_auto_capture" : "",
((compile_options & PCRE2_NO_AUTO_POSSESS) != 0)? ",no_auto_possess" : "",
((compile_options & PCRE2_NO_DOTSTAR_ANCHOR) != 0)? ",no_dotstar_anchor" : "",
((compile_options & PCRE2_NO_UTF_CHECK) != 0)? ",no_utf_check" : "",
((compile_options & PCRE2_NO_START_OPTIMIZE) != 0)? ",no_start_optimize" : "",
((compile_options & PCRE2_UCP) != 0)? ",ucp" : "",
((compile_options & PCRE2_UNGREEDY) != 0)? ",ungreedy" : "",
((compile_options & PCRE2_USE_OFFSET_LIMIT) != 0)? ",use_offset_limit" : "",
((compile_options & PCRE2_UTF) != 0)? ",utf" : "");
#endif
code = pcre2_compile((PCRE2_SPTR)data, (PCRE2_SIZE)size, compile_options,
&errorcode, &erroroffset, NULL);
if (code != NULL)
{
int j;
uint32_t save_match_options = match_options;
/* Create a match data block only when we first need it. */
if (match_data == NULL)
{
match_data = pcre2_match_data_create(32, NULL);
if (match_data == NULL)
{
#ifdef STANDALONE
printf("** Failed to create match data block\n");
#endif
return 0;
}
}
/* Match twice, with and without options */
for (j = 0; j < 2; j++)
{
#ifdef STANDALONE
printf("Match with options %.8x", match_options);
printf("%s%s%s%s%s%s%s%s\n",
((match_options & PCRE2_ANCHORED) != 0)? ",anchored" : "",
((match_options & PCRE2_NO_UTF_CHECK) != 0)? ",no_utf_check" : "",
((match_options & PCRE2_NOTBOL) != 0)? ",notbol" : "",
((match_options & PCRE2_NOTEMPTY) != 0)? ",notempty" : "",
((match_options & PCRE2_NOTEMPTY_ATSTART) != 0)? ",notempty_atstart" : "",
((match_options & PCRE2_NOTEOL) != 0)? ",noteol" : "",
((match_options & PCRE2_PARTIAL_HARD) != 0)? ",partial_hard" : "",
((match_options & PCRE2_PARTIAL_SOFT) != 0)? ",partial_soft" : "");
#endif
errorcode = pcre2_match(code, (PCRE2_SPTR)data, (PCRE2_SIZE)size, 0,
match_options, match_data, NULL);
#ifdef STANDALONE
if (errorcode >= 0) printf("Match returned %d\n", errorcode); else
{
unsigned char buffer[256];
pcre2_get_error_message(errorcode, buffer, 256);
printf("Match failed: error %d: %s\n", errorcode, buffer);
}
#endif
match_options = 0; /* For second time */
}
match_options = save_match_options; /* Reset for the second compile */
pcre2_code_free(code);
}
#ifdef STANDALONE
else
{
unsigned char buffer[256];
pcre2_get_error_message(errorcode, buffer, 256);
printf("Compile failed: error %d at offset %lu: %s\n", errorcode,
erroroffset, buffer);
}
#endif
compile_options = PCRE2_NEVER_BACKSLASH_C; /* For second time */
}
if (match_data != NULL) pcre2_match_data_free(match_data);
return 0;
}
/* Optional main program. */
#ifdef STANDALONE
int main(int argc, char **argv)
{
int i;
if (argc < 2)
{
printf("** No arguments given\n");
return 0;
}
for (i = 1; i < argc; i++)
{
size_t filelen;
size_t readsize;
unsigned char *buffer;
FILE *f;
/* Handle a literal string. Copy to an exact size buffer so that checks for
overrunning work. */
if (argv[i][0] == '=')
{
readsize = strlen(argv[i]) - 1;
printf("------ <Literal> ------\n");
printf("Length = %lu\n", readsize);
printf("%.*s\n", (int)readsize, argv[i]+1);
buffer = (unsigned char *)malloc(readsize);
if (buffer == NULL)
printf("** Failed to allocate %lu bytes of memory\n", readsize);
else
{
memcpy(buffer, argv[i]+1, readsize);
LLVMFuzzerTestOneInput(buffer, readsize);
free(buffer);
}
continue;
}
/* Handle a string given in a file */
f = fopen(argv[i], "rb");
if (f == NULL)
{
printf("** Failed to open %s: %s\n", argv[i], strerror(errno));
continue;
}
printf("------ %s ------\n", argv[i]);
fseek(f, 0, SEEK_END);
filelen = ftell(f);
fseek(f, 0, SEEK_SET);
buffer = (unsigned char *)malloc(filelen);
if (buffer == NULL)
{
printf("** Failed to allocate %lu bytes of memory\n", filelen);
fclose(f);
continue;
}
readsize = fread(buffer, 1, filelen, f);
fclose(f);
if (readsize != filelen)
printf("** File size is %lu but fread() returned %lu\n", filelen, readsize);
else
{
printf("Length = %lu\n", filelen);
LLVMFuzzerTestOneInput(buffer, filelen);
}
free(buffer);
}
return 0;
}
#endif /* STANDALONE */
/* End */