CVE-2013-6401: Change hash function, randomize hashes

Thanks to Florian Weimer and Eric Sesterhenn for reporting, reviewing
and testing.

1 files changed, 48 insertions, 2 deletions

diff --git a/configure.ac b/configure.ac
index 24ba37d..113cb85 100644
--- a/configure.ac
+++ b/configure.ac
@@ -14,10 +14,11 @@ AM_CONDITIONAL([GCC], [test x$GCC = xyes])
 # Checks for libraries.
 
 # Checks for header files.
-AC_CHECK_HEADERS([locale.h])
+AC_CHECK_HEADERS([endian.h fcntl.h locale.h sched.h unistd.h sys/param.h sys/stat.h sys/time.h sys/types.h])
 
 # Checks for typedefs, structures, and compiler characteristics.
 AC_TYPE_INT32_T
+AC_TYPE_UINT32_T
 AC_TYPE_LONG_LONG_INT
 
 AC_C_INLINE
@@ -29,7 +30,31 @@ esac
 AC_SUBST([json_inline])
 
 # Checks for library functions.
-AC_CHECK_FUNCS([strtoll localeconv])
+AC_CHECK_FUNCS([close getpid gettimeofday localeconv open read sched_yield strtoll])
+
+AC_MSG_CHECKING([for gcc __sync builtins])
+have_sync_builtins=no
+AC_TRY_LINK(
+  [], [unsigned long val; __sync_bool_compare_and_swap(&val, 0, 1);],
+  [have_sync_builtins=yes],
+)
+if test "x$have_sync_builtins" = "xyes"; then
+  AC_DEFINE([HAVE_SYNC_BUILTINS], [1],
+    [Define to 1 if gcc's __sync builtins are available])
+fi
+AC_MSG_RESULT([$have_sync_builtins])
+
+AC_MSG_CHECKING([for gcc __atomic builtins])
+have_atomic_builtins=no
+AC_TRY_LINK(
+  [], [char l; unsigned long v; __atomic_test_and_set(&l, __ATOMIC_RELAXED); __atomic_store_n(&v, 1, __ATOMIC_ACQ_REL); __atomic_load_n(&v, __ATOMIC_ACQUIRE);],
+  [have_atomic_builtins=yes],
+)
+if test "x$have_atomic_builtins" = "xyes"; then
+  AC_DEFINE([HAVE_ATOMIC_BUILTINS], [1],
+    [Define to 1 if gcc's __atomic builtins are available])
+fi
+AC_MSG_RESULT([$have_atomic_builtins])
 
 case "$ac_cv_type_long_long_int$ac_cv_func_strtoll" in
      yesyes) json_have_long_long=1;;
@@ -43,6 +68,27 @@ case "$ac_cv_header_locale_h$ac_cv_func_localeconv" in
 esac
 AC_SUBST([json_have_localeconv])
 
+# Features
+AC_ARG_ENABLE([urandom],
+  [AS_HELP_STRING([--disable-urandom],
+    [Don't use /dev/urandom to seed the hash function])],
+  [use_urandom=$enableval], [use_urandom=yes])
+
+if test "x$use_urandom" = xyes; then
+AC_DEFINE([USE_URANDOM], [1],
+  [Define to 1 if /dev/urandom should be used for seeding the hash function])
+fi
+
+AC_ARG_ENABLE([windows-cryptoapi],
+  [AS_HELP_STRING([--disable-windows-cryptoapi],
+    [Don't use CryptGenRandom to seed the hash function])],
+  [use_windows_cryptoapi=$enableval], [use_windows_cryptoapi=yes])
+
+if test "x$use_windows_cryptoapi" = xyes; then
+AC_DEFINE([USE_WINDOWS_CRYPTOAPI], [1],
+  [Define to 1 if CryptGenRandom should be used for seeding the hash function])
+fi
+
 AC_CONFIG_FILES([
         jansson.pc
         Makefile