pr feedback: feature tests

tests/features/S2N_LIBCRYPTO_SUPPORTS_ENGINE.c

@@ -30,10 +30,6 @@
  */
 #include <openssl/engine.h>
 
-#if defined(OPENSSL_NO_ENGINE)
-    #error "engine is not supported"
-#endif
-
 int s2n_noop_rand(unsigned char *buf, int num)
 {
     return 1;

tests/unit/s2n_random_test.c

@@ -899,8 +899,22 @@ int main(int argc, char **argv)
 
     /* Feature probe */
     {
-#if defined(S2N_LIBCRYPTO_SUPPORTS_ENGINE) && defined(OPENSSL_NO_ENGINE)
-        FAIL_MSG("Logic error with the Engine feature probe.")
+#if defined(OPENSSL_IS_AWSLC)
+        /* Negative test */
+    #if defined(S2N_LIBCRYPTO_SUPPORTS_ENGINE)
+        FAIL_MSG("Expected ENGINE feature probe to be disabled with AWS-LC");
+    #endif
+
+#else
+
+        /* Positive test
+         *
+         * We expect ENGINE APIs to be available if `OPENSSL_NO_ENGINE` is not
+         * defined.
+         */
+    #if !defined(OPENSSL_NO_ENGINE) && !defined(S2N_LIBCRYPTO_SUPPORTS_ENGINE)
+        FAIL_MSG("Expected ENGINE feature probe to be enabled");
+    #endif
 #endif
     };
 
@@ -916,6 +930,10 @@ int main(int argc, char **argv)
 #if !defined(S2N_LIBCRYPTO_SUPPORTS_ENGINE)
         EXPECT_FALSE(s2n_supports_custom_rand());
 #endif
+
+#if defined(OPENSSL_NO_ENGINE)
+        EXPECT_FALSE(s2n_supports_custom_rand());
+#endif
     };
 
     /* For each test case, creates a child process that runs the test case.

utils/s2n_random.c

@@ -553,6 +553,8 @@ bool s2n_supports_custom_rand()
 {
 #if !defined(S2N_LIBCRYPTO_SUPPORTS_ENGINE)
     return false;
+#elif defined(OPENSSL_NO_ENGINE)
+    return false;
 #else
     return !s2n_libcrypto_is_boringssl() && !s2n_libcrypto_is_libressl() && !s2n_libcrypto_is_awslc() && !s2n_is_in_fips_mode();
 #endif