generator: add ctr_inc() fun

generator.cpp

@@ -10,6 +10,7 @@
 #include <fmt/core.h>
 
 #include <algorithm>
+#include <atomic>
 #include <cassert>
 #include <chrono>
 #include <cmath>
@@ -216,6 +217,22 @@ auto Generator::generate_random_data(const unsigned int& n) -> std::string {
 	return r;
 }
 
+auto Generator::ctr_inc() -> void {
+	// increment the least-significant-byte-first ctr
+
+	std::atomic<uint8_t> i{0};
+	while (true) {
+		this->G.counter.at(i) = static_cast<std::byte>(
+			static_cast<uint8_t>(this->G.counter.at(i)) + 0x01);
+
+		if (this->G.counter.at(i) == static_cast<std::byte>(0x00) &&
+			++i < this->G.counter.size()) {
+			continue;
+		}
+		break;
+	}
+}
+
 
 } // namespace generator
 } // namespace fortuna

generator.h

@@ -66,6 +66,8 @@ private:
 
 	auto generate_blocks(unsigned int k_blocks) -> std::string;
 
+	auto ctr_inc() -> void;
+
 protected:
 	auto get_state() const -> Generator::G_state;