Use function name FIPS_drbg_health_check() for health check function.
authorDr. Stephen Henson <steve@openssl.org>
Thu, 22 Sep 2011 14:01:25 +0000 (14:01 +0000)
committerDr. Stephen Henson <steve@openssl.org>
Thu, 22 Sep 2011 14:01:25 +0000 (14:01 +0000)
Add explanatory comments to health check code.

CHANGES
fips/rand/fips_drbg_lib.c
fips/rand/fips_drbg_selftest.c
fips/rand/fips_rand.h

diff --git a/CHANGES b/CHANGES
index 85dabd2..cdd1dc1 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -5,8 +5,8 @@
  Changes between 1.0.1 and 1.1.0  [xx XXX xxxx]
 
   *) Use separate DRBG fields for internal and external flags. New function
-     FIPS_drbg_test() to perform on demand health checking. Add generation
-     tests to fips_test_suite with reduced health check interval to 
+     FIPS_drbg_health_check() to perform on demand health checking. Add
+     generation tests to fips_test_suite with reduced health check interval to 
      demonstrate periodic health checking. Add "nodh" option to
      fips_test_suite to skip very slow DH test.
      [Steve Henson]
index 9873742..b5aed01 100644 (file)
@@ -1,4 +1,3 @@
-/* fips/rand/fips_drbg_lib.c */
 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
  * project.
  */
@@ -95,11 +94,9 @@ int FIPS_drbg_init(DRBG_CTX *dctx, int type, unsigned int flags)
 
        if (!(dctx->xflags & DRBG_FLAG_TEST))
                {
-               DRBG_CTX tctx;
-               if (!fips_drbg_kat(&tctx, type, flags | DRBG_FLAG_TEST))
+               if (!FIPS_drbg_health_check(dctx))
                        {
                        FIPSerr(FIPS_F_FIPS_DRBG_INIT, FIPS_R_SELFTEST_FAILURE);
-                       dctx->status = DRBG_STATUS_ERROR;
                        return 0;
                        }
                }
@@ -308,7 +305,7 @@ static int drbg_reseed(DRBG_CTX *dctx,
         */
        if (hcheck && !(dctx->xflags & DRBG_FLAG_TEST))
                {
-               if (!FIPS_drbg_test(dctx))
+               if (!FIPS_drbg_health_check(dctx))
                        {
                        r = FIPS_R_SELFTEST_FAILURE;
                        goto end;
@@ -357,13 +354,11 @@ static int fips_drbg_check(DRBG_CTX *dctx)
        dctx->health_check_cnt++;
        if (dctx->health_check_cnt >= dctx->health_check_interval)
                {
-               if (!FIPS_drbg_test(dctx))
+               if (!FIPS_drbg_health_check(dctx))
                        {
                        FIPSerr(FIPS_F_FIPS_DRBG_CHECK, FIPS_R_SELFTEST_FAILURE);
-                       dctx->status = DRBG_STATUS_ERROR;
                        return 0;
                        }
-               dctx->health_check_cnt = 0;
                }
        return 1;
        }
index a73bbe6..abff9af 100644 (file)
@@ -206,6 +206,10 @@ static int fips_drbg_single_kat(DRBG_CTX *dctx, DRBG_SELFTEST_DATA *td,
 
        /* Initial test without PR */
 
+       /* Instantiate DRBG with test entropy, nonce and personalisation
+        * string.
+        */
+
        if (!FIPS_drbg_init(dctx, td->nid, td->flags))
                return 0;
        if (!FIPS_drbg_set_callbacks(dctx, test_entropy, 0, 0, test_nonce, 0))
@@ -231,6 +235,8 @@ static int fips_drbg_single_kat(DRBG_CTX *dctx, DRBG_SELFTEST_DATA *td,
                adinlen = td->adinlen / 2;
        else
                adinlen = td->adinlen;
+
+       /* Generate with no PR and verify output matches expected data */
        if (!FIPS_drbg_generate(dctx, randout, td->katlen, 0,
                                td->adin, adinlen))
                goto err;
@@ -240,19 +246,20 @@ static int fips_drbg_single_kat(DRBG_CTX *dctx, DRBG_SELFTEST_DATA *td,
                FIPSerr(FIPS_F_FIPS_DRBG_SINGLE_KAT, FIPS_R_NOPR_TEST1_FAILURE);
                goto err2;
                }
-
+       /* If abbreviated POST end of test */
        if (quick)
                {
                rv = 1;
                goto err;
                }
-
+       /* Reseed DRBG with test entropy and additional input */
        t.ent = td->entreseed;
        t.entlen = td->entreseedlen;
 
        if (!FIPS_drbg_reseed(dctx, td->adinreseed, td->adinreseedlen))
                goto err;
 
+       /* Generate with no PR and verify output matches expected data */
        if (!FIPS_drbg_generate(dctx, randout, td->kat2len, 0,
                                td->adin2, td->adin2len))
                goto err;
@@ -266,6 +273,10 @@ static int fips_drbg_single_kat(DRBG_CTX *dctx, DRBG_SELFTEST_DATA *td,
        FIPS_drbg_uninstantiate(dctx);
 
        /* Now test with PR */
+
+       /* Instantiate DRBG with test entropy, nonce and personalisation
+        * string.
+        */
        if (!FIPS_drbg_init(dctx, td->nid, td->flags))
                return 0;
        if (!FIPS_drbg_set_callbacks(dctx, test_entropy, 0, 0, test_nonce, 0))
@@ -283,6 +294,10 @@ static int fips_drbg_single_kat(DRBG_CTX *dctx, DRBG_SELFTEST_DATA *td,
        if (!FIPS_drbg_instantiate(dctx, td->pers_pr, td->perslen_pr))
                goto err;
 
+       /* Now generate with PR: we need to supply entropy as this will
+        * perform a reseed operation. Check output matches expected value.
+        */
+
        t.ent = td->entpr_pr;
        t.entlen = td->entprlen_pr;
 
@@ -304,6 +319,10 @@ static int fips_drbg_single_kat(DRBG_CTX *dctx, DRBG_SELFTEST_DATA *td,
                goto err2;
                }
 
+       /* Now generate again with PR: supply new entropy again.
+        * Check output matches expected value.
+        */
+
        t.ent = td->entg_pr;
        t.entlen = td->entglen_pr;
 
@@ -316,7 +335,7 @@ static int fips_drbg_single_kat(DRBG_CTX *dctx, DRBG_SELFTEST_DATA *td,
                FIPSerr(FIPS_F_FIPS_DRBG_SINGLE_KAT, FIPS_R_PR_TEST2_FAILURE);
                goto err2;
                }
-
+       /* All OK, test complete */
        rv = 1;
 
        err:
@@ -363,11 +382,13 @@ static int do_drbg_instantiate(DRBG_CTX *dctx, DRBG_SELFTEST_DATA *td,
        return 1;
        }
 
-/* This is the "health check" function required by SP800-90. Induce several
- * failure modes and check an error condition is set.
+/* This function performd extensive error checking as required by SP800-90.
+ * Induce several failure modes and check an error condition is set.
+ * This function along with fips_drbg_single_kat peforms the health checking
+ * operation.
  */
 
-static int fips_drbg_health_check(DRBG_CTX *dctx, DRBG_SELFTEST_DATA *td)
+static int fips_drbg_error_check(DRBG_CTX *dctx, DRBG_SELFTEST_DATA *td)
        {
        unsigned char randout[1024];
        TEST_ENT t;
@@ -773,13 +794,13 @@ int fips_drbg_kat(DRBG_CTX *dctx, int nid, unsigned int flags)
                        {
                        if (!fips_drbg_single_kat(dctx, td, 0))
                                return 0;
-                       return fips_drbg_health_check(dctx, td);
+                       return fips_drbg_error_check(dctx, td);
                        }
                }
        return 0;
        }
 
-int FIPS_drbg_test(DRBG_CTX *dctx)
+int FIPS_drbg_health_check(DRBG_CTX *dctx)
        {
        int rv;
        DRBG_CTX *tctx = NULL;
@@ -794,6 +815,10 @@ int FIPS_drbg_test(DRBG_CTX *dctx)
                fips_post_success(FIPS_TEST_DRBG, dctx->type, &dctx->xflags);
        else
                fips_post_failed(FIPS_TEST_DRBG, dctx->type, &dctx->xflags);
+       if (!rv)
+               dctx->status = DRBG_STATUS_ERROR;
+       else
+               dctx->health_check_cnt = 0;
        return rv;
        }
 
@@ -843,7 +868,7 @@ int FIPS_selftest_drbg_all(void)
                        rv = 0;
                        continue;
                        }
-               if (!fips_drbg_health_check(dctx, td))
+               if (!fips_drbg_error_check(dctx, td))
                        {
                        fips_post_failed(FIPS_TEST_DRBG, td->nid, &td->flags);
                        rv = 0;
index dc33cf1..ef9b822 100644 (file)
@@ -115,7 +115,7 @@ int FIPS_drbg_get_strength(DRBG_CTX *dctx);
 void FIPS_drbg_set_check_interval(DRBG_CTX *dctx, int interval);
 void FIPS_drbg_set_reseed_interval(DRBG_CTX *dctx, int interval);
 
-int FIPS_drbg_test(DRBG_CTX *dctx);
+int FIPS_drbg_health_check(DRBG_CTX *dctx);
 
 DRBG_CTX *FIPS_get_default_drbg(void);
 const RAND_METHOD *FIPS_drbg_method(void);