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>

3 files changed, 48 insertions, 0 deletions

diff --git a/crypto/api.c b/crypto/api.c
index 0444d242e985..cd232d4dfc41 100644
--- a/crypto/api.c
+++ b/crypto/api.c
@@ -493,5 +493,19 @@ int crypto_has_alg(const char *name, u32 type, u32 mask)
 }
 EXPORT_SYMBOL_GPL(crypto_has_alg);
 
+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);
+
 MODULE_DESCRIPTION("Cryptographic core API");
 MODULE_LICENSE("GPL");
diff --git a/crypto/internal.h b/crypto/internal.h
index fc93743c5d3e..b7fcd3024875 100644
--- a/crypto/internal.h
+++ b/crypto/internal.h
@@ -26,6 +26,8 @@
 #include <linux/rwsem.h>
 #include <linux/slab.h>
 
+extern int fips_enabled;
+
 /* Crypto notification events. */
 enum {
 	CRYPTO_MSG_ALG_REQUEST,
diff --git a/crypto/proc.c b/crypto/proc.c
index 1d616adead0d..29601dcfd0d3 100644
--- a/crypto/proc.c
+++ b/crypto/proc.c
@@ -19,8 +19,37 @@
 #include <linux/rwsem.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
+#include <linux/sysctl.h>
 #include "internal.h"
 
+static struct ctl_table crypto_sysctl_table[] = {
+	{
+		.ctl_name       = CTL_UNNUMBERED,
+		.procname       = "fips_enabled",
+		.data           = &fips_enabled,
+		.maxlen         = sizeof(int),
+		.mode           = 0444,
+		.proc_handler   = &proc_dointvec
+	},
+	{
+		.ctl_name = 0,
+	},
+};
+
+static struct ctl_table crypto_dir_table[] = {
+	{
+		.ctl_name       = CTL_UNNUMBERED,
+		.procname       = "crypto",
+		.mode           = 0555,
+		.child          = crypto_sysctl_table
+	},
+	{
+		.ctl_name = 0,
+	},
+};
+
+static struct ctl_table_header *crypto_sysctls;
+
 static void *c_start(struct seq_file *m, loff_t *pos)
 {
 	down_read(&crypto_alg_sem);
@@ -106,9 +135,12 @@ static const struct file_operations proc_crypto_ops = {
 void __init crypto_init_proc(void)
 {
 	proc_create("crypto", 0, NULL, &proc_crypto_ops);
+	crypto_sysctls = register_sysctl_table(crypto_dir_table);
 }
 
 void __exit crypto_exit_proc(void)
 {
 	remove_proc_entry("crypto", NULL);
+	if (crypto_sysctls)
+		unregister_sysctl_table(crypto_sysctls);
 }