random: Add optional continuous repetition test to entropy store based rngs

FIPS-140 requires that all random number generators implement continuous self
tests in which each extracted block of data is compared against the last block
for repetition.  The ansi_cprng implements such a test, but it would be nice if
the hw rng's did the same thing.  Obviously its not something thats always
needed, but it seems like it would be a nice feature to have on occasion. I've
written the below patch which allows individual entropy stores to be flagged as
desiring a continuous test to be run on them as is extracted.  By default this
option is off, but is enabled in the event that fips mode is selected during
bootup.

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

1 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/fips.h b/include/linux/fips.h
new file mode 100644
index 000000000000..f8fb07b0b6b8
--- /dev/null
+++ b/include/linux/fips.h
@@ -0,0 +1,10 @@
+#ifndef _FIPS_H
+#define _FIPS_H
+
+#ifdef CONFIG_CRYPTO_FIPS
+extern int fips_enabled;
+#else
+#define fips_enabled 0
+#endif
+
+#endif