Fix "CORS Rejected - Invalid origin" issue when origin header is empty (#6988)

Signed-off-by: Ameziane H <ameziane.hamlat@consensys.net>

ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/JsonRpcHttpService.java

@@ -312,7 +312,8 @@ public class JsonRpcHttpService {
     router
         .route()
         .handler(
-            CorsHandler.create(buildCorsRegexFromConfig())
+            CorsHandler.create()
+                .addRelativeOrigin(buildCorsRegexFromConfig())
                 .allowedHeader("*")
                 .allowedHeader("content-type"));
     router
@@ -569,7 +570,7 @@ public class JsonRpcHttpService {
       return "";
     }
     if (config.getCorsAllowedDomains().contains("*")) {
-      return ".*://.*";
+      return ".*://.*|.*";
     } else {
       final StringJoiner stringJoiner = new StringJoiner("|");
       config.getCorsAllowedDomains().stream().filter(s -> !s.isEmpty()).forEach(stringJoiner::add);

ethereum/api/src/test/java/org/hyperledger/besu/ethereum/api/jsonrpc/JsonRpcHttpServiceCorsTest.java

@@ -166,6 +166,18 @@ public class JsonRpcHttpServiceCorsTest {
     }
   }
 
+  @Test
+  public void requestWithAnyOriginAndEmptyActualOriginShouldSucceed() throws Exception {
+    jsonRpcHttpService = createJsonRpcHttpServiceWithAllowedDomains("*");
+
+    final Request request =
+        new Request.Builder().url(jsonRpcHttpService.url()).header("Origin", "").build();
+
+    try (final Response response = client.newCall(request).execute()) {
+      assertThat(response.isSuccessful()).isTrue();
+    }
+  }
+
   @Test
   public void requestFromBrowserExtensionShouldSucceedWhenCorsIsStar() throws Exception {
     jsonRpcHttpService = createJsonRpcHttpServiceWithAllowedDomains("*");