diff --git a/include/MacStd/CoreFoundation.hpp b/include/MacStd/CoreFoundation.hpp
index 0ae82d3..ffb830d 100644
--- a/include/MacStd/CoreFoundation.hpp
+++ b/include/MacStd/CoreFoundation.hpp
@@ -44,9 +44,54 @@ namespace macstd {
 	using cfdictionary = cfobject<CFDictionaryRef>;
 	using cferror = cfobject<CFErrorRef>;
 	using cfreadstream = cfobject<CFReadStreamRef>;
-	using cfstring = cfobject<CFStringRef>;
 	using cfurl = cfobject<CFURLRef>;
 
+	template <typename TR = std::char_traits<char>, typename A = std::allocator<char>>
+	void strcat(std::basic_string<char, TR, A>& str, CFStringRef h, CFStringEncoding encoding = kCFStringEncodingUTF8)
+	{
+		auto ptr = CFStringGetCStringPtr(h, encoding);
+		if (ptr) {
+			str += ptr;
+			return;
+		}
+		char buf[0x200];
+		if (CFStringGetCString(h, buf, sizeof(buf)/sizeof(*buf), encoding)) {
+			str += buf;
+			return;
+		}
+		auto n = str.size();
+		auto m = CFStringGetMaximumSizeForEncoding(CFStringGetLength(h), encoding);
+		str.resize(n + m);
+		if (!CFStringGetCString(h, &str[n], m, encoding)) [[unlikely]]
+			throw std::runtime_error("CFStringGetCString failed");
+		str.resize(n + strlen(&str[n]));
+	}
+
+	template <typename TR = std::char_traits<char>, typename A = std::allocator<char>>
+	void strcpy(std::basic_string<char, TR, A>& str, CFStringRef h, CFStringEncoding encoding = kCFStringEncodingUTF8)
+	{
+		str.clear();
+		strcat(str, h, encoding);
+	}
+
+	///
+	/// Core Foundation string
+	///
+	class cfstring : public cfobject<CFStringRef>
+	{
+	public:
+		cfstring(CFStringRef h) : cfobject<CFStringRef>(h) {}
+
+		cfstring(const char *s) : cfobject<CFStringRef>(CFStringCreateWithCString(kCFAllocatorDefault, s, kCFStringEncodingUTF8))
+		{
+			if (!valid()) [[unlikely]]
+				throw std::bad_alloc();
+		}
+
+		template <typename TR, typename A>
+		cfstring(const std::basic_string<char, TR, A> &s) : cfstring(s.c_str()) {}
+	};
+
 	///
 	/// Core Foundation runtime error
 	///
@@ -126,18 +171,18 @@ namespace macstd {
 		///
 		static std::string message(CFErrorRef error)
 		{
-			macstd::cfstring description(CFErrorCopyDescription(error));
-			if (description.valid() && CFStringGetLength(description) > 0) {
-				auto str = CFStringGetCStringPtr(description, kCFStringEncodingUTF8);
-				if (str)
-					return str;
+			std::string msg;
+			cfstring cfstr(CFErrorCopyDescription(error));
+			if (cfstr.valid() && CFStringGetLength(cfstr) > 0) {
+				strcpy(msg, cfstr, kCFStringEncodingUTF8);
+			} else {
+				msg = "Core Foundation error ";
+				msg += std::to_string(CFErrorGetCode(error));
 			}
-			std::string msg("Core Foundation error " + std::to_string(CFErrorGetCode(error)));
-			macstd::cfstring domain(CFErrorGetDomain(error));
+			cfstring domain(CFErrorGetDomain(error));
 			if (domain.valid() && CFStringGetLength(domain) > 0) {
-				auto str = CFStringGetCStringPtr(domain, kCFStringEncodingUTF8);
-				if (str)
-					msg += std::string(", domain ") + str;
+				msg += ", domain ";
+				strcat(msg, domain, kCFStringEncodingUTF8);
 			}
 			return msg;
 		}
diff --git a/include/MacStd/Security.hpp b/include/MacStd/Security.hpp
index 0c11d9c..1555411 100644
--- a/include/MacStd/Security.hpp
+++ b/include/MacStd/Security.hpp
@@ -62,14 +62,15 @@ namespace macstd
 				case errAuthorizationDenied: return "Authorization was denied";
 				case errAuthorizationInteractionNotAllowed: return "User interaction not allowed for authorization";
 			}
+			std::string msg;
 			cfstring cfstr(SecCopyErrorMessageString(num, NULL));
-			if (!cfstr.valid())
-				return "Security Framework error " + std::to_string(num);
-			auto ptr = CFStringGetCStringPtr(cfstr, kCFStringEncodingUTF8);
-			if (!ptr)
-				return "Security Framework error " + std::to_string(num);
-			std::string str(ptr);
-			return str;
+			if (cfstr.valid() && CFStringGetLength(cfstr) > 0) {
+				strcpy(msg, cfstr, kCFStringEncodingUTF8);
+			} else {
+				msg = "Security Framework error ";
+				msg += std::to_string(num);
+			}
+			return msg;
 		}
 	};