Everywhere: Hoist the Libraries folder to the top-level

Author: https://github.com/trflynn89
Commit: 93712b24bf
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2256
Reviewed-by: https://github.com/sideshowbarker

Libraries/LibCrypto/Cipher/Cipher.h

@@ -0,0 +1,124 @@
+/*
+ * Copyright (c) 2020, Ali Mohammad Pur <mpfard@serenityos.org>
+ * Copyright (c) 2022, the SerenityOS developers.
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Optional.h>
+#include <AK/Span.h>
+#include <AK/Types.h>
+
+namespace Crypto::Cipher {
+
+enum class Intent {
+    Encryption,
+    Decryption,
+};
+
+enum class PaddingMode {
+    CMS,     // RFC 1423
+    RFC5246, // very similar to CMS, but filled with |length - 1|, instead of |length|
+    Null,
+    ZeroLength,
+    // FIXME: We do not implement these yet
+    Bit,
+    Random,
+    Space,
+};
+
+bool padding_always_needs_extra_block(PaddingMode);
+
+template<typename B, typename T>
+class Cipher;
+
+struct CipherBlock {
+public:
+    explicit CipherBlock(PaddingMode mode)
+        : m_padding_mode(mode)
+    {
+    }
+
+    virtual ReadonlyBytes bytes() const = 0;
+
+    virtual void overwrite(ReadonlyBytes) = 0;
+    virtual void overwrite(u8 const* data, size_t size) { overwrite({ data, size }); }
+
+    virtual void apply_initialization_vector(ReadonlyBytes ivec) = 0;
+
+    PaddingMode padding_mode() const { return m_padding_mode; }
+    void set_padding_mode(PaddingMode mode) { m_padding_mode = mode; }
+
+    template<typename T>
+    void put(size_t offset, T value)
+    {
+        VERIFY(offset + sizeof(T) <= bytes().size());
+        auto* ptr = bytes().offset_pointer(offset);
+        auto index { 0 };
+
+        VERIFY(sizeof(T) <= 4);
+
+        if constexpr (sizeof(T) > 3)
+            ptr[index++] = (u8)(value >> 24);
+
+        if constexpr (sizeof(T) > 2)
+            ptr[index++] = (u8)(value >> 16);
+
+        if constexpr (sizeof(T) > 1)
+            ptr[index++] = (u8)(value >> 8);
+
+        ptr[index] = (u8)value;
+    }
+
+protected:
+    virtual ~CipherBlock() = default;
+
+private:
+    virtual Bytes bytes() = 0;
+    PaddingMode m_padding_mode;
+};
+
+struct CipherKey {
+    virtual ReadonlyBytes bytes() const = 0;
+    static bool is_valid_key_size(size_t) { return false; }
+
+    virtual ~CipherKey() = default;
+
+protected:
+    virtual void expand_encrypt_key(ReadonlyBytes user_key, size_t bits) = 0;
+    virtual void expand_decrypt_key(ReadonlyBytes user_key, size_t bits) = 0;
+    size_t bits { 0 };
+};
+
+template<typename KeyT = CipherKey, typename BlockT = CipherBlock>
+class Cipher {
+public:
+    using KeyType = KeyT;
+    using BlockType = BlockT;
+
+    explicit Cipher(PaddingMode mode)
+        : m_padding_mode(mode)
+    {
+    }
+
+    virtual KeyType const& key() const = 0;
+    virtual KeyType& key() = 0;
+
+    constexpr static size_t block_size() { return BlockType::block_size(); }
+
+    PaddingMode padding_mode() const { return m_padding_mode; }
+
+    virtual void encrypt_block(BlockType const& in, BlockType& out) = 0;
+    virtual void decrypt_block(BlockType const& in, BlockType& out) = 0;
+
+    virtual ByteString class_name() const = 0;
+
+protected:
+    virtual ~Cipher() = default;
+
+private:
+    PaddingMode m_padding_mode;
+};
+}