Add integrity hash support and SRP tuning options

include/auth/integrity.hpp

@@ -0,0 +1,35 @@
+#pragma once
+
+#include <array>
+#include <cstdint>
+#include <string>
+#include <vector>
+
+namespace wowee {
+namespace auth {
+
+// Computes the LOGON_PROOF "CRC hash" / integrity hash for the legacy WoW login protocol.
+//
+// Algorithm (per WoWDev/gtker docs):
+//   checksum = HMAC_SHA1(checksumSalt, concatenated_file_bytes)
+//   crc_hash = SHA1(clientPublicKey || checksum)
+//
+// clientPublicKey is the 32-byte A as sent on the wire.
+//
+// Returns false if any file is missing/unreadable.
+bool computeIntegrityHashWin32(const std::array<uint8_t, 16>& checksumSalt,
+                               const std::vector<uint8_t>& clientPublicKeyA,
+                               const std::string& miscDir,
+                               std::array<uint8_t, 20>& outHash,
+                               std::string& outError);
+
+// Same as computeIntegrityHashWin32, but allows selecting the EXE filename used in the file set.
+bool computeIntegrityHashWin32WithExe(const std::array<uint8_t, 16>& checksumSalt,
+                                      const std::vector<uint8_t>& clientPublicKeyA,
+                                      const std::string& miscDir,
+                                      const std::string& exeName,
+                                      std::array<uint8_t, 20>& outHash,
+                                      std::string& outError);
+
+} // namespace auth
+} // namespace wowee