Split off gc-random from gc, and only warn on missing devices.

[gnulib.git] / m4 / gc-random.m4

diff --git a/m4/gc-random.m4 b/m4/gc-random.m4
new file mode 100644 (file)
index 0000000..02cef21
--- /dev/null
+++ b/m4/gc-random.m4
@@ -0,0 +1,81 @@
+# gc-random.m4 serial 1
+dnl Copyright (C) 2005, 2006 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?
+
+  case "${target}" in
+    *-openbsd*)
+      NAME_OF_RANDOM_DEVICE="/dev/srandom"
+      NAME_OF_PSEUDO_RANDOM_DEVICE="/dev/prandom"
+      NAME_OF_NONCE_DEVICE="/dev/urandom"
+      ;;
+
+    *-netbsd*)
+      NAME_OF_RANDOM_DEVICE="/dev/srandom"
+      NAME_OF_PSEUDO_RANDOM_DEVICE="/dev/urandom"
+      NAME_OF_NONCE_DEVICE="/dev/urandom"
+      ;;
+
+    *-solaris* | *-irix* | *-dec-osf* )
+      NAME_OF_RANDOM_DEVICE="/dev/random"
+      NAME_OF_PSEUDO_RANDOM_DEVICE="/dev/random"
+      NAME_OF_NONCE_DEVICE="/dev/random"
+      ;;
+
+    *)
+      NAME_OF_RANDOM_DEVICE="/dev/random"
+      NAME_OF_PSEUDO_RANDOM_DEVICE="/dev/urandom"
+      NAME_OF_NONCE_DEVICE="/dev/urandom"
+      ;;
+  esac
+
+  AC_MSG_CHECKING([device with (strong) random data...])
+  AC_ARG_ENABLE(random-device,
+       AC_HELP_STRING([--enable-random-device],
+               [device with (strong) randomness (for Nettle)]),
+       test "$enableval" != "no" && 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)]),
+       test "$enableval" != "no" && NAME_OF_PSEUDO_RANDOM_DEVICE=$enableval)
+  AC_MSG_RESULT($NAME_OF_PSEUDO_RANDOM_DEVICE)
+
+  AC_MSG_CHECKING([device with unpredictable data for nonces...])
+  AC_ARG_ENABLE(nonce-device,
+       AC_HELP_STRING([--enable-nonce-device],
+               [device with unpredictable nonces (for Nettle)]),
+       test "$enableval" != "no" && NAME_OF_NONCE_DEVICE=$enableval)
+  AC_MSG_RESULT($NAME_OF_NONCE_DEVICE)
+
+  if test "$cross_compiling" != yes; then
+    AC_CHECK_FILE($NAME_OF_RANDOM_DEVICE,,
+      AC_MSG_WARN([[device for (strong) random data `$NAME_OF_RANDOM_DEVICE' does not exist]]))
+    AC_CHECK_FILE($NAME_OF_PSEUDO_RANDOM_DEVICE,,
+      AC_MSG_WARN([[device for pseudo-random data `$NAME_OF_PSEUDO_RANDOM_DEVICE' does not exist]]))
+    AC_CHECK_FILE($NAME_OF_NONCE_DEVICE,,
+      AC_MSG_WARN([[device for unpredictable nonces `$NAME_OF_NONCE_DEVICE' does not exist]]))
+  else
+    AC_MSG_NOTICE([[Cross compiling, assuming random devices exists on the target host...]])  
+  fi
+
+  # FIXME?: Open+read 42 bytes+close twice and compare data.  Should differ.
+
+  AC_DEFINE_UNQUOTED(NAME_OF_RANDOM_DEVICE, "$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])
+
+  AC_DEFINE(GC_USE_RANDOM, 1, [Define if you want to support RNG through GC.])
+])