Add periodic DRBG health checks as required by SP800-90.
diff --git a/crypto/fips_err.h b/crypto/fips_err.h
index 8c7a68c..0c2aa44 100644
--- a/crypto/fips_err.h
+++ b/crypto/fips_err.h
@@ -82,6 +82,7 @@
{ERR_FUNC(FIPS_F_FIPS_CIPHERINIT), "FIPS_CIPHERINIT"},
{ERR_FUNC(FIPS_F_FIPS_DIGESTINIT), "FIPS_DIGESTINIT"},
{ERR_FUNC(FIPS_F_FIPS_DRBG_BYTES), "FIPS_DRBG_BYTES"},
+{ERR_FUNC(FIPS_F_FIPS_DRBG_CHECK), "FIPS_DRBG_CHECK"},
{ERR_FUNC(FIPS_F_FIPS_DRBG_CPRNG_TEST), "FIPS_DRBG_CPRNG_TEST"},
{ERR_FUNC(FIPS_F_FIPS_DRBG_GENERATE), "FIPS_drbg_generate"},
{ERR_FUNC(FIPS_F_FIPS_DRBG_HEALTH_CHECK), "FIPS_DRBG_HEALTH_CHECK"},
diff --git a/fips/fips.h b/fips/fips.h
index f9c3dde..155cbbc 100644
--- a/fips/fips.h
+++ b/fips/fips.h
@@ -244,6 +244,7 @@
#define FIPS_F_FIPS_CIPHERINIT 109
#define FIPS_F_FIPS_DIGESTINIT 110
#define FIPS_F_FIPS_DRBG_BYTES 111
+#define FIPS_F_FIPS_DRBG_CHECK 146
#define FIPS_F_FIPS_DRBG_CPRNG_TEST 112
#define FIPS_F_FIPS_DRBG_GENERATE 113
#define FIPS_F_FIPS_DRBG_HEALTH_CHECK 114
diff --git a/fips/rand/fips_drbg_lib.c b/fips/rand/fips_drbg_lib.c
index 10d549b..6d983aa 100644
--- a/fips/rand/fips_drbg_lib.c
+++ b/fips/rand/fips_drbg_lib.c
@@ -71,6 +71,9 @@
dctx->flags = flags;
dctx->type = type;
+ dctx->health_check_cnt = 0;
+ dctx->health_check_interval = DRBG_HEALTH_INTERVAL;
+
rv = fips_drbg_hash_init(dctx);
if (rv == -2)
@@ -277,6 +280,24 @@
return 0;
}
+static int fips_drbg_check(DRBG_CTX *dctx)
+ {
+ if (dctx->flags & DRBG_FLAG_TEST)
+ return 1;
+ dctx->health_check_cnt++;
+ if (dctx->health_check_cnt >= dctx->health_check_interval)
+ {
+ DRBG_CTX tctx;
+ if (!fips_drbg_kat(&tctx, dctx->type,
+ dctx->flags | DRBG_FLAG_TEST))
+ {
+ FIPSerr(FIPS_F_FIPS_DRBG_CHECK, FIPS_R_SELFTEST_FAILURE);
+ return 0;
+ }
+ dctx->health_check_cnt = 0;
+ }
+ return 1;
+ }
int FIPS_drbg_generate(DRBG_CTX *dctx, unsigned char *out, size_t outlen,
int strength, int prediction_resistance,
@@ -284,6 +305,9 @@
{
int r = 0;
+ if (!fips_drbg_check(dctx))
+ return 0;
+
if (dctx->status != DRBG_STATUS_READY
&& dctx->status != DRBG_STATUS_RESEED)
{
@@ -408,6 +432,11 @@
return dctx->strength;
}
+void FIPS_drbg_set_check_interval(DRBG_CTX *dctx, int interval)
+ {
+ dctx->health_check_interval = interval;
+ }
+
static int drbg_stick = 0;
void FIPS_drbg_stick(void)
diff --git a/fips/rand/fips_rand.h b/fips/rand/fips_rand.h
index 6186c00..44a3c4f 100644
--- a/fips/rand/fips_rand.h
+++ b/fips/rand/fips_rand.h
@@ -108,6 +108,7 @@
void FIPS_drbg_set_app_data(DRBG_CTX *ctx, void *app_data);
size_t FIPS_drbg_get_blocklength(DRBG_CTX *dctx);
int FIPS_drbg_get_strength(DRBG_CTX *dctx);
+void FIPS_drbg_set_check_interval(DRBG_CTX *dctx, int interval);
DRBG_CTX *FIPS_get_default_drbg(void);
const RAND_METHOD *FIPS_drbg_method(void);
diff --git a/fips/rand/fips_rand_lcl.h b/fips/rand/fips_rand_lcl.h
index 94f58ea..eeed0ec 100644
--- a/fips/rand/fips_rand_lcl.h
+++ b/fips/rand/fips_rand_lcl.h
@@ -105,6 +105,8 @@
*/
#define DRBG_MAX_BLOCK EVP_MAX_MD_SIZE
+#define DRBG_HEALTH_INTERVAL (1 << 24)
+
/* DRBG context structure */
struct drbg_ctx_st
@@ -114,6 +116,8 @@
int type;
/* Various flags */
unsigned int flags;
+ /* Used for periodic health checks */
+ int health_check_cnt, health_check_interval;
/* The following parameters are setup by mechanism drbg_init() call */
int strength;
