Core/Authserver: Authserver cleanup (PR#25093)

- Fix a handful of 1/256 bugs with most significant byte zero in BigNumber
- Get rid of (most of) the C-style arrays in authserver
- CryptoRandom as a unified source for cryptographic randomness
- Bring our other crypto APIs into 2020
- BigNumber usability improvements
- Authserver is now actually readable as a result of all of the above

(cherry picked from commit 210176fd915cf4ba16f428d3c1a249a71f4aa7a7)

1 files changed, 117 insertions, 0 deletions

diff --git a/src/common/Cryptography/CryptoGenerics.h b/src/common/Cryptography/CryptoGenerics.h
new file mode 100644
index 00000000000..affa11bf79d
--- /dev/null
+++ b/src/common/Cryptography/CryptoGenerics.h
@@ -0,0 +1,117 @@
+/*
+ * This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef TRINITY_CRYPTO_GENERICS_HPP
+#define TRINITY_CRYPTO_GENERICS_HPP
+
+#include "BigNumber.h"
+#include "CryptoRandom.h"
+#include "Define.h"
+#include "Errors.h"
+#include <iterator>
+#include <vector>
+
+namespace Trinity
+{
+namespace Impl
+{
+    struct CryptoGenericsImpl
+    {
+        template <typename Cipher>
+        static typename Cipher::IV GenerateRandomIV()
+        {
+            typename Cipher::IV iv;
+            Trinity::Crypto::GetRandomBytes(iv);
+            return iv;
+        }
+
+        template <typename Container>
+        static void AppendToBack(std::vector<uint8>& data, Container const& tail)
+        {
+            data.insert(data.end(), std::begin(tail), std::end(tail));
+        }
+
+        template <typename Container>
+        static void SplitFromBack(std::vector<uint8>& data, Container& tail)
+        {
+            ASSERT(data.size() >= std::size(tail));
+            for (size_t i = 1, N = std::size(tail); i <= N; ++i)
+            {
+                tail[N - i] = data.back();
+                data.pop_back();
+            }
+        }
+    };
+}
+}
+
+namespace Trinity
+{
+namespace Crypto
+{
+    template <typename Cipher>
+    void AEEncryptWithRandomIV(std::vector<uint8>& data, typename Cipher::Key const& key)
+    {
+        using IV = typename Cipher::IV;
+        using Tag = typename Cipher::Tag;
+        // select random IV
+        IV iv = Trinity::Impl::CryptoGenericsImpl::GenerateRandomIV<Cipher>();
+        Tag tag;
+
+        // encrypt data
+        Cipher cipher(true);
+        cipher.Init(key);
+        bool success = cipher.Process(iv, data.data(), data.size(), tag);
+        ASSERT(success);
+
+        // append trailing IV and tag
+        Trinity::Impl::CryptoGenericsImpl::AppendToBack(data, iv);
+        Trinity::Impl::CryptoGenericsImpl::AppendToBack(data, tag);
+    }
+
+    template <typename Cipher>
+    void AEEncryptWithRandomIV(std::vector<uint8>& data, BigNumber const& key)
+    {
+        AEEncryptWithRandomIV<Cipher>(data, key.ToByteArray<Cipher::KEY_SIZE_BYTES>());
+    }
+
+    template <typename Cipher>
+    bool AEDecrypt(std::vector<uint8>& data, typename Cipher::Key const& key)
+    {
+        using IV = typename Cipher::IV;
+        using Tag = typename Cipher::Tag;
+        // extract trailing IV and tag
+        IV iv;
+        Tag tag;
+        Trinity::Impl::CryptoGenericsImpl::SplitFromBack(data, tag);
+        Trinity::Impl::CryptoGenericsImpl::SplitFromBack(data, iv);
+
+        // decrypt data
+        Cipher cipher(false);
+        cipher.Init(key);
+        return cipher.Process(iv, data.data(), data.size(), tag);
+    }
+
+    template <typename Cipher>
+    bool AEDecrypt(std::vector<uint8>& data, BigNumber const& key)
+    {
+        return AEDecrypt<Cipher>(data, key.ToByteArray<Cipher::KEY_SIZE_BYTES>());
+    }
+}
+}
+
+#endif