Rework searching for openssl

The installation path for openssl may vary depending on the way
used for its installation and the macOS version.

This commit attempts to find the correct path for openssl to use.

Makefile

@@ -92,18 +92,25 @@ ifeq ($(TEST_ASYNC),1)
 endif
 
 ifeq ($(USE_SSL),1)
-  ifeq ($(uname_S),Linux)
-    ifdef OPENSSL_PREFIX
-      CFLAGS+=-I$(OPENSSL_PREFIX)/include
-      SSL_LDFLAGS+=-L$(OPENSSL_PREFIX)/lib -lssl -lcrypto
-    else
-      SSL_LDFLAGS=-lssl -lcrypto
+  ifndef OPENSSL_PREFIX
+    ifeq ($(uname_S),Darwin)
+      SEARCH_PATH1=/opt/homebrew/opt/openssl
+      SEARCH_PATH2=/usr/local/opt/openssl
+
+      ifneq ($(wildcard $(SEARCH_PATH1)),)
+        OPENSSL_PREFIX=$(SEARCH_PATH1)
+      else ifneq($(wildcard $(SEARCH_PATH2)),)
+        OPENSSL_PREFIX=$(SEARCH_PATH2)
+      endif
     endif
-  else
-    OPENSSL_PREFIX?=/usr/local/opt/openssl
-    CFLAGS+=-I$(OPENSSL_PREFIX)/include
-    SSL_LDFLAGS+=-L$(OPENSSL_PREFIX)/lib -lssl -lcrypto
   endif
+
+  ifdef OPENSSL_PREFIX
+    CFLAGS+=-I$(OPENSSL_PREFIX)/include
+    SSL_LDFLAGS+=-L$(OPENSSL_PREFIX)/lib
+  endif
+
+  SSL_LDFLAGS+=-lssl -lcrypto
 endif
 
 ifeq ($(uname_S),FreeBSD)