[PATCH 2/3] crypto: jitter - don't limit ->health_failure check to FIPS mode

Nicolai Stange
2021-11-30T14:10:40Z

The jitterentropy's Repetition Count Test (RCT) as well as the Adaptive
Proportion Test (APT) are run unconditionally on any collected samples.
However, their result, i.e. ->health_failure, will only get checked if
fips_enabled is set, c.f. the jent_health_failure() wrapper.

I would argue that a RCT or APT failure indicates that something's
seriously off and that this should always be reported as an error,
independently of whether FIPS mode is enabled or not: it should be up to
callers whether or not and how to handle jitterentropy failures.

Make jent_health_failure() to unconditionally return ->health_failure,
independent of whether fips_enabled is set.

Note that fips_enabled isn't accessed from the jitterentropy code anymore
now. Remove the linux/fips.h include as well as the jent_fips_enabled()
wrapper.

Signed-off-by: Nicolai Stange <nstange@suse.de>
---
crypto/jitterentropy-kcapi.c | 6 ------
crypto/jitterentropy.c | 4 ----
crypto/jitterentropy.h | 1 -
3 files changed, 11 deletions(-)

diff --git a/crypto/jitterentropy-kcapi.c b/crypto/jitterentropy-kcapi.c
index e8a4165a1874..2d115bec15ae 100644
--- a/crypto/jitterentropy-kcapi.c
+++ b/crypto/jitterentropy-kcapi.c
@@ -40,7 +40,6 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
-#include <linux/fips.h>
#include <linux/time.h>
#include <crypto/internal/rng.h>

@@ -60,11 +59,6 @@ void jent_zfree(void *ptr)
kfree_sensitive(ptr);
}

-int jent_fips_enabled(void)
-{
- return fips_enabled;
-}
-
void jent_panic(char *s)
{
panic("%s", s);
diff --git a/crypto/jitterentropy.c b/crypto/jitterentropy.c
index 788d90749715..24e087c3f526 100644
--- a/crypto/jitterentropy.c
+++ b/crypto/jitterentropy.c
@@ -298,10 +298,6 @@ static int jent_stuck(struct rand_data *ec, __u64 current_delta)
*/
static int jent_health_failure(struct rand_data *ec)
{
- /* Test is only enabled in FIPS mode */
- if (!jent_fips_enabled())
- return 0;
-
return ec->health_failure;
}

diff --git a/crypto/jitterentropy.h b/crypto/jitterentropy.h
index c83fff32d130..b7397b617ef0 100644
--- a/crypto/jitterentropy.h
+++ b/crypto/jitterentropy.h
@@ -2,7 +2,6 @@

extern void *jent_zalloc(unsigned int len);
extern void jent_zfree(void *ptr);
-extern int jent_fips_enabled(void);
extern void jent_panic(char *s);
extern void jent_memcpy(void *dest, const void *src, unsigned int n);
extern void jent_get_nstime(__u64 *out);
--
2.26.2