From 0c194bc8046cb3ecb4e4d0577f36a1d3bde58d11 Mon Sep 17 00:00:00 2001
From: boris <wzn@moneybot.cc>
Date: Thu, 27 Dec 2018 22:42:05 +1300
Subject: bap

---
 csgo-loader/csgo-server/Security/FnvHash.hpp | 100 +++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)
 create mode 100644 csgo-loader/csgo-server/Security/FnvHash.hpp

(limited to 'csgo-loader/csgo-server/Security')

diff --git a/csgo-loader/csgo-server/Security/FnvHash.hpp b/csgo-loader/csgo-server/Security/FnvHash.hpp
new file mode 100644
index 0000000..35c9ad0
--- /dev/null
+++ b/csgo-loader/csgo-server/Security/FnvHash.hpp
@@ -0,0 +1,100 @@
+#pragma once
+#include <cstdint>
+#include <type_traits>
+
+// Credits: namazso
+// Implements FNV-1a hash algorithm
+namespace detail
+{
+	template <typename Type, Type OffsetBasis, Type Prime>
+	struct SizeDependantData
+	{
+		using type = Type;
+
+		constexpr static auto k_offset_basis = OffsetBasis;
+		constexpr static auto k_prime = Prime;
+	};
+
+	template <std::size_t Bits>
+	struct SizeSelector : std::false_type {};
+
+	template <>
+	struct SizeSelector<32> : SizeDependantData<std::uint32_t, 0x811c9dc5ul, 16777619ul> {};
+
+	template <>
+	struct SizeSelector<64> : SizeDependantData<std::uint64_t, 0xcbf29ce484222325ull, 1099511628211ull> {};
+
+	template <std::size_t Size>
+	class FnvHash
+	{
+	private:
+		using data_t = SizeSelector<Size>;
+
+	public:
+		using hash = typename data_t::type;
+
+	private:
+		constexpr static auto k_offset_basis = data_t::k_offset_basis;
+		constexpr static auto k_prime = data_t::k_prime;
+
+	public:
+		static __forceinline constexpr auto hash_init(
+		) -> hash
+		{
+			return k_offset_basis;
+		}
+
+		static __forceinline constexpr auto hash_byte(
+			hash current,
+			std::uint8_t byte
+		) -> hash
+		{
+			return (current ^ byte) * k_prime;
+		}
+
+		template <std::size_t N>
+		static __forceinline constexpr auto hash_constexpr(
+			const char(&str)[N],
+			const std::size_t size = N - 1 /* do not hash the null */
+		) -> hash
+		{
+			const auto prev_hash = size == 1 ? hash_init() : hash_constexpr(str, size - 1);
+			const auto cur_hash = hash_byte(prev_hash, str[size - 1]);
+			return cur_hash;
+		}
+
+		static auto __forceinline hash_runtime_data(
+			const void* data,
+			const std::size_t sz
+		) -> hash
+		{
+			const auto bytes = static_cast<const uint8_t*>(data);
+			const auto end = bytes + sz;
+			auto result = hash_init();
+			for(auto it = bytes; it < end; ++it)
+				result = hash_byte(result, *it);
+
+			return result;
+		}
+
+		static auto __forceinline hash_runtime(
+			const char* str
+		) -> hash
+		{
+			auto result = hash_init();
+			do
+				result = hash_byte(result, *str++);
+			while(*str != '\0');
+
+			return result;
+		}
+	};
+}
+
+using fnv32 = ::detail::FnvHash<32>;
+using fnv64 = ::detail::FnvHash<64>;
+using fnv = ::detail::FnvHash<sizeof(void*) * 8>;
+
+#define FNV(str) (std::integral_constant<fnv::hash, fnv::hash_constexpr(str)>::value)
+#define FNV32(str) (std::integral_constant<fnv32::hash, fnv32::hash_constexpr(str)>::value)
+#define FNV64(str) (std::integral_constant<fnv64::hash, fnv64::hash_constexpr(str)>::value)
\ No newline at end of file
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