Implemented a Key::Random() method

GCryptLib/include/GCrypt/Key.h

@@ -11,7 +11,12 @@ namespace Leonetienne::GCrypt {
   */
   class Key : public Block {
     public:
+      //! Will generate a key from a password
       static Key FromPassword(const std::string& password);
+
+      //! Will generate a random key from actual randomness (std::random_device)
+      static Key Random();
+
       Key();
       Key(const Key& k);
       Key(const Block& b);

GCryptLib/src/Key.cpp

@@ -1,6 +1,8 @@
 #include "GCrypt/Key.h"
 #include "GCrypt/GHash.h"
 #include "GCrypt/Util.h"
+#include <random>
+#include <cassert>
 
 namespace Leonetienne::GCrypt {
 
@@ -10,6 +12,24 @@ namespace Leonetienne::GCrypt {
     );
   }
 
+  Key Key::Random() {
+    // Create our truly-random rng
+    std::random_device rng;
+    constexpr std::size_t bitsPerCall = sizeof(std::random_device::result_type) * 8;
+
+    // Fetch BLOCK_SIZE bits
+    std::stringstream ss;
+    for (std::size_t i = 0; i < BLOCK_SIZE / bitsPerCall; i++) {
+      ss << std::bitset<bitsPerCall>(rng());
+    }
+
+    // Verify that we actually have the correct size
+    assert(ss.str().length() == BLOCK_SIZE);
+
+    // Return them as a key
+    return Key(Block(ss.str()));
+  }
+
   Key::Key() : Block() {
   }