evp_test: add a ctx dup operation to the KDF tests

Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
(Merged from #17572)

(cherry picked from commit c8adf19)
Reviewed-by: Hugo Landau <hlandau@openssl.org>

test/evp_test.c

@@ -2808,6 +2808,7 @@ static int kdf_test_run(EVP_TEST *t)
     KDF_DATA *expected = t->data;
     unsigned char *got = NULL;
     size_t got_len = expected->output_len;
+    EVP_KDF_CTX *ctx;
 
     if (!EVP_KDF_CTX_set_params(expected->ctx, expected->params)) {
         t->err = "KDF_CTRL_ERROR";
@@ -2817,6 +2818,10 @@ static int kdf_test_run(EVP_TEST *t)
         t->err = "INTERNAL_ERROR";
         goto err;
     }
+    if ((ctx = EVP_KDF_CTX_dup(expected->ctx)) != NULL) {
+        EVP_KDF_CTX_free(expected->ctx);
+        expected->ctx = ctx;
+    }
     if (EVP_KDF_derive(expected->ctx, got, got_len, NULL) <= 0) {
         t->err = "KDF_DERIVE_ERROR";
         goto err;