crypto: api - Add fips_enable flag

Add the ability to turn FIPS-compliant mode on or off at boot

In order to be FIPS compliant, several check may need to be preformed that may
be construed as unusefull in a non-compliant mode.  This patch allows us to set
a kernel flag incating that we are running in a fips-compliant mode from boot
up.  It also exports that mode information to user space via a sysctl
(/proc/sys/crypto/fips_enabled).

Tested successfully by me.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/fips.c

@@ -0,0 +1,27 @@
+/*
+ * FIPS 200 support.
+ *
+ * Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+
+#include "internal.h"
+
+int fips_enabled;
+EXPORT_SYMBOL_GPL(fips_enabled);
+
+/* Process kernel command-line parameter at boot time. fips=0 or fips=1 */
+static int fips_enable(char *str)
+{
+	fips_enabled = !!simple_strtol(str, NULL, 0);
+	printk(KERN_INFO "fips mode: %s\n",
+		fips_enabled ? "enabled" : "disabled");
+	return 1;
+}
+
+__setup("fips=", fips_enable);