Added utility function to convert byteArray to HEX string. Useful for printing fingerprint digests etc.

src/vmime/utility/stringUtils.hpp

@@ -29,6 +29,7 @@
 #include "vmime/base.hpp"
 
 #include <sstream>
+#include <iostream>
 
 
 namespace vmime {
@@ -52,6 +53,20 @@ public:
 		return string(reinterpret_cast <const char*>(data), count);
 	}
 
+	/** Makes a HEX string from byteArray.
+	  *
+	  * @param data byteArray containing data
+	  * @return a string object containing a hex copy of the specified data
+	  */
+	static const string makeHexStringFromBytes(const byteArray& data) {
+		std::stringstream ss;
+		for (const byte_t& b : data)
+		{
+			ss << std::hex << int(b);
+		}
+		return ss.str();
+	}
+
 	/** Casts a string to bytes.
 	  *
 	  * @param str string