Add periodic DRBG health checks as required by SP800-90.
authorDr. Stephen Henson <steve@openssl.org>
Wed, 20 Apr 2011 17:06:38 +0000 (17:06 +0000)
committerDr. Stephen Henson <steve@openssl.org>
Wed, 20 Apr 2011 17:06:38 +0000 (17:06 +0000)
crypto/fips_err.h
fips/fips.h
fips/rand/fips_drbg_lib.c
fips/rand/fips_rand.h
fips/rand/fips_rand_lcl.h

index 8c7a68c..0c2aa44 100644 (file)
@@ -82,6 +82,7 @@ static ERR_STRING_DATA FIPS_str_functs[]=
 {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"},
index f9c3dde..155cbbc 100644 (file)
@@ -244,6 +244,7 @@ void ERR_load_FIPS_strings(void);
 #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
index 10d549b..6d983aa 100644 (file)
@@ -71,6 +71,9 @@ int FIPS_drbg_init(DRBG_CTX *dctx, int type, unsigned int flags)
        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 @@ int FIPS_drbg_reseed(DRBG_CTX *dctx,
        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 FIPS_drbg_generate(DRBG_CTX *dctx, unsigned char *out, size_t outlen,
        {
        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 @@ int FIPS_drbg_get_strength(DRBG_CTX *dctx)
        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)
index 6186c00..44a3c4f 100644 (file)
@@ -108,6 +108,7 @@ void *FIPS_drbg_get_app_data(DRBG_CTX *ctx);
 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);
index 94f58ea..eeed0ec 100644 (file)
@@ -105,6 +105,8 @@ struct drbg_ctr_ctx_st
  */
 #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 @@ struct drbg_ctx_st
        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;