Cosmetic rand/drbg changes.

Reviewed-by: NMatthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/8554)

(cherry picked from commit b3d113ed2993801ee643126118ccf6592ad18ef7)

crypto/rand/drbg_lib.c

@@ -188,8 +188,8 @@ static RAND_DRBG *rand_drbg_new(int secure,
                                 unsigned int flags,
                                 RAND_DRBG *parent)
 {
-    RAND_DRBG *drbg = secure ?
-        OPENSSL_secure_zalloc(sizeof(*drbg)) : OPENSSL_zalloc(sizeof(*drbg));
+    RAND_DRBG *drbg = secure ? OPENSSL_secure_zalloc(sizeof(*drbg))
+                             : OPENSSL_zalloc(sizeof(*drbg));
 
     if (drbg == NULL) {
         RANDerr(RAND_F_RAND_DRBG_NEW, ERR_R_MALLOC_FAILURE);

crypto/rand/rand_lib.c

@@ -137,7 +137,7 @@ size_t rand_drbg_get_entropy(RAND_DRBG *drbg,
     size_t entropy_available = 0;
     RAND_POOL *pool;
 
-    if (drbg->parent && drbg->strength > drbg->parent->strength) {
+    if (drbg->parent != NULL && drbg->strength > drbg->parent->strength) {
         /*
          * We currently don't support the algorithm from NIST SP 800-90C
          * 10.1.2 to use a weaker DRBG as source
@@ -155,7 +155,7 @@ size_t rand_drbg_get_entropy(RAND_DRBG *drbg,
             return 0;
     }
 
-    if (drbg->parent) {
+    if (drbg->parent != NULL) {
         size_t bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);
         unsigned char *buffer = rand_pool_add_begin(pool, bytes_needed);
 
@@ -235,7 +235,7 @@ size_t rand_drbg_get_nonce(RAND_DRBG *drbg,
     struct {
         void * instance;
         int count;
-    } data = { 0 };
+    } data = { NULL, 0 };
 
     pool = rand_pool_new(0, min_len, max_len);
     if (pool == NULL)
@@ -402,7 +402,7 @@ int RAND_poll(void)
     } else {
         /* fill random pool and seed the current legacy RNG */
         pool = rand_pool_new(RAND_DRBG_STRENGTH,
-                             RAND_DRBG_STRENGTH / 8,
+                             (RAND_DRBG_STRENGTH + 7) / 8,
                              RAND_POOL_MAX_LENGTH);
         if (pool == NULL)
             return 0;
@@ -689,7 +689,7 @@ unsigned char *rand_pool_add_begin(RAND_POOL *pool, size_t len)
 
     if (pool->buffer == NULL) {
         RANDerr(RAND_F_RAND_POOL_ADD_BEGIN, ERR_R_INTERNAL_ERROR);
-        return 0;
+        return NULL;
     }
 
     return pool->buffer + pool->len;