Renamed class Hasher to GHash

GCryptLib/src/GHash.cpp

@@ -0,0 +1,57 @@
+#include "GCrypt/GHash.h"
+#include "GCrypt/Util.h"
+#include "GCrypt/InitializationVector.h"
+
+namespace Leonetienne::GCrypt {
+
+  GHash::GHash() :
+    // Initialize our cipher with a static, but randomly distributed key.
+    cipher(
+        StringToBitblock("CfRtNdMTP4Y5CWRd"),
+        GCipher::DIRECTION::ENCIPHER
+    ) {
+      block = InitializationVector(StringToBitblock("3J7IipfQTDJbO8jtasz9PgWui6faPaEMOuVuAqyhB1S2CRcLw5caawewgDUEG1WN"));
+
+      return;
+  }
+
+  void GHash::DigestBlock(const Block& data) {
+    // Encipher the current block, and xor it on the current hashsum
+    block ^= cipher.Digest(data);
+    return;
+  }
+
+  const Block& GHash::GetHashsum() const {
+    return block;
+  }
+
+  Block GHash::CalculateHashsum(const Flexblock& data) {
+    // Split input into blocks
+    std::vector<Block> blocks;
+
+    for (std::size_t i = 0; i < data.size(); i += BLOCK_SIZE) {
+      blocks.push_back(Block(
+        PadStringToLength(data.substr(i, BLOCK_SIZE), BLOCK_SIZE, '0', false))
+      );
+    }
+
+    // Add an additional block, containing the length of the input
+    std::stringstream ss;
+    ss << data.length();
+    const Block lengthBlock = StringToBitblock(ss.str());
+    blocks.push_back(lengthBlock);
+
+    // Create hasher instance
+    GHash hasher;
+
+    // Digest all blocks
+    for (Block& block : blocks) {
+      hasher.DigestBlock(block);
+    }
+
+    // Return the total hashsum
+    return hasher.GetHashsum();
+  }
+
+}
+