# gc-random.m4 serial 2
dnl Copyright (C) 2005-2007 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.

AC_DEFUN([gl_GC_RANDOM],
[
  # Devices with randomness.
  # FIXME: Are these the best defaults?

  AC_REQUIRE([AC_CANONICAL_HOST])dnl

  case "$host_os" in
    *openbsd*)
      NAME_OF_RANDOM_DEVICE="/dev/srandom"
      NAME_OF_PSEUDO_RANDOM_DEVICE="/dev/prandom"
      NAME_OF_NONCE_DEVICE="/dev/urandom"
      ;;

    *netbsd*)
      NAME_OF_RANDOM_DEVICE="/dev/srandom"
      NAME_OF_PSEUDO_RANDOM_DEVICE="/dev/urandom"
      NAME_OF_NONCE_DEVICE="/dev/urandom"
      ;;

    *solaris* | *irix* | *dec-osf* )
      NAME_OF_RANDOM_DEVICE="/dev/random"
      NAME_OF_PSEUDO_RANDOM_DEVICE="/dev/random"
      NAME_OF_NONCE_DEVICE="/dev/random"
      ;;

    *)
      NAME_OF_RANDOM_DEVICE="/dev/random"
      NAME_OF_PSEUDO_RANDOM_DEVICE="/dev/urandom"
      NAME_OF_NONCE_DEVICE="/dev/urandom"
      ;;
  esac

  AC_MSG_CHECKING([device with (strong) random data...])
  AC_ARG_ENABLE(random-device,
	AC_HELP_STRING([--enable-random-device],
		[device with (strong) randomness (for Nettle)]),
	NAME_OF_RANDOM_DEVICE=$enableval)
  AC_MSG_RESULT($NAME_OF_RANDOM_DEVICE)

  AC_MSG_CHECKING([device with pseudo random data...])
  AC_ARG_ENABLE(pseudo-random-device,
	AC_HELP_STRING([--enable-pseudo-random-device],
		[device with pseudo randomness (for Nettle)]),
	NAME_OF_PSEUDO_RANDOM_DEVICE=$enableval)
  AC_MSG_RESULT($NAME_OF_PSEUDO_RANDOM_DEVICE)

  AC_MSG_CHECKING([device with unpredictable data for nonces...])
  AC_ARG_ENABLE(nonce-device,
	AC_HELP_STRING([--enable-nonce-device],
		[device with unpredictable nonces (for Nettle)]),
	NAME_OF_NONCE_DEVICE=$enableval)
  AC_MSG_RESULT($NAME_OF_NONCE_DEVICE)

  if test "$cross_compiling" != yes; then
    if test "$NAME_OF_RANDOM_DEVICE" != "no"; then
      AC_CHECK_FILE($NAME_OF_RANDOM_DEVICE,,
        AC_MSG_WARN([[Device `$NAME_OF_RANDOM_DEVICE' does not exist, consider to use --enable-random-device]]))
    fi
    if test "$NAME_OF_PSEUDO_RANDOM_DEVICE" != "no"; then
      AC_CHECK_FILE($NAME_OF_PSEUDO_RANDOM_DEVICE,,
        AC_MSG_WARN([[Device `$NAME_OF_PSEUDO_RANDOM_DEVICE' does not exist, consider to use --enable-pseudo-random-device]]))
    fi
    if test "$NAME_OF_NONCE_DEVICE" != "no"; then
      AC_CHECK_FILE($NAME_OF_NONCE_DEVICE,,
        AC_MSG_WARN([[Device `$NAME_OF_NONCE_DEVICE' does not exist, consider to use --enable-nonce-device]]))
    fi
  else
    AC_MSG_NOTICE([[Cross compiling, assuming random devices exists on the target host...]])  
  fi

  # FIXME?: Open+read 42 bytes+close twice and compare data.  Should differ.

  AC_DEFINE_UNQUOTED(NAME_OF_RANDOM_DEVICE, "$NAME_OF_RANDOM_DEVICE",
                   [defined to the name of the (strong) random device])
  AC_DEFINE_UNQUOTED(NAME_OF_PSEUDO_RANDOM_DEVICE,
			 "$NAME_OF_PSEUDO_RANDOM_DEVICE",
                   [defined to the name of the pseudo random device])
  AC_DEFINE_UNQUOTED(NAME_OF_NONCE_DEVICE, "$NAME_OF_NONCE_DEVICE",
                   [defined to the name of the unpredictable nonce device])
])