Fixes for minor scan-build warnings

Author: lealem47

examples/client/client.c

@@ -2950,7 +2950,9 @@ THREAD_RETURN WOLFSSL_THREAD client_test(void* args)
 #endif /* HAVE_RPK */
                 break;
             case 268:
+#ifndef NO_CERTS
                 fileFormat = WOLFSSL_FILETYPE_ASN1;
+#endif
                 break;
             case 269:
 #if defined(WOLFSSL_SYS_CRYPTO_POLICY)

src/tls13.c

@@ -10558,6 +10558,7 @@ static int DoTls13CertificateVerify(WOLFSSL* ssl, byte* input,
         case TLS_ASYNC_DO:
         {
             sig = input + args->idx;
+            (void)sig;
         #ifdef WOLFSSL_DUAL_ALG_CERTS
             if (ssl->sigSpec != NULL &&
                 *ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_BOTH) {

tests/api.c

@@ -20118,7 +20118,7 @@ static int test_wolfSSL_PKCS7_certs(void)
         while (EXPECT_SUCCESS() && (sk_X509_INFO_num(info_sk) > 0)) {
             X509_INFO* info = NULL;
             ExpectNotNull(info = sk_X509_INFO_shift(info_sk));
-            if (info != NULL) {
+            if (EXPECT_SUCCESS() && info != NULL) {
                 ExpectIntGT(sk_X509_push(sk, info->x509), 0);
                 info->x509 = NULL;
             }

wolfcrypt/src/random.c

@@ -4207,8 +4207,9 @@ int wc_GenerateSeed(OS_Seed* os, byte* output, word32 sz)
         #ifdef FORCE_FAILURE_GETRANDOM
             /* don't fallback to /dev/urandom */
             return ret;
-        #else
-            /* reset error and fallback to using /dev/urandom */
+        #elif !defined(NO_FILESYSTEM)
+            /* reset error and fallback to using /dev/urandom if filesystem
+             * support is compiled in */
             ret = 0;
         #endif
         }

wolfcrypt/src/sp_int.c

@@ -8561,10 +8561,11 @@ int sp_rshb(const sp_int* a, int n, sp_int* r)
         }
         else {
             /* Move the bits down starting at least significant digit. */
-            for (j = 0; i < a->used - 1; i++, j++)
-                r->dp[j] = (a->dp[i] >> n) | (a->dp[i+1] << (SP_WORD_SIZE - n));
+            for (j = 0; j < (sp_size_t)(a->used - 1 - i); j++)
+                r->dp[j] = (a->dp[j+i] >> n) |
+                    (a->dp[j+i+1] << (SP_WORD_SIZE - n));
             /* Most significant digit has no higher digit to pull from. */
-            r->dp[j] = a->dp[i] >> n;
+            r->dp[j] = a->dp[j+i] >> n;
             /* Set the count of used digits. */
             r->used = (sp_size_t)(j + (r->dp[j] > 0));
         }