Cipher.h

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/*
* Copyright 2010-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
*  http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file is distributed
* on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied. See the License for the specific language governing
* permissions and limitations under the License.
*/

#pragma once

#include <aws/core/Core_EXPORTS.h>
#include <aws/core/utils/Array.h>
#include <aws/core/utils/memory/stl/AWSStreamFwd.h>

namespace Aws
{
    namespace Utils
    {
        namespace Crypto
        {
            static const size_t SYMMETRIC_KEY_LENGTH = 32;
            static const size_t MIN_IV_LENGTH = 12;

            class AWS_CORE_API SymmetricCipher
            {
            public:
                SymmetricCipher(const CryptoBuffer& key, size_t ivSize, bool ivGenerationInCtrMode = false) :
                        m_key(key), m_initializationVector(GenerateIV(ivSize, ivGenerationInCtrMode)), m_failure(false) { Validate(); }

                SymmetricCipher(const CryptoBuffer& key, const CryptoBuffer& initializationVector, const CryptoBuffer& tag = CryptoBuffer(0)) :
                        m_key(key), m_initializationVector(initializationVector), m_tag(tag), m_failure(false) { Validate(); }

                SymmetricCipher(CryptoBuffer&& key, CryptoBuffer&& initializationVector, CryptoBuffer&& tag = CryptoBuffer(0)) :
                        m_key(std::move(key)), m_initializationVector(std::move(initializationVector)), m_tag(std::move(tag)), m_failure(false) { Validate(); }

                SymmetricCipher(const SymmetricCipher& other) = delete;
                SymmetricCipher& operator=(const SymmetricCipher& other) = delete;

                SymmetricCipher(SymmetricCipher&& toMove) :
                        m_key(std::move(toMove.m_key)),
                        m_initializationVector(std::move(toMove.m_initializationVector)),
                        m_tag(std::move(toMove.m_tag)),
                        m_failure(toMove.m_failure)
                {
                    Validate();
                }

                SymmetricCipher& operator=(SymmetricCipher&& toMove)
                {
                    m_key = std::move(toMove.m_key);
                    m_initializationVector = std::move(toMove.m_initializationVector);
                    m_tag = std::move(toMove.m_tag);
                    m_failure = toMove.m_failure;

                    Validate();

                    return *this;
                }

                virtual ~SymmetricCipher() = default;

                operator bool() const { return Good(); }

                virtual CryptoBuffer EncryptBuffer( const CryptoBuffer& unEncryptedData) = 0;

                virtual CryptoBuffer FinalizeEncryption () = 0;

                virtual CryptoBuffer DecryptBuffer(const CryptoBuffer& encryptedData) = 0;

                virtual CryptoBuffer FinalizeDecryption () = 0;

                virtual void Reset() = 0;

                inline const CryptoBuffer& GetIV() const { return m_initializationVector; }

                inline const CryptoBuffer& GetTag() const { return m_tag; }

                inline bool Fail() const { return m_failure; }
                inline bool Good() const { return !Fail(); }

                static CryptoBuffer GenerateIV(size_t ivLengthBytes, bool ctrMode = false);

                static CryptoBuffer GenerateKey(size_t keyLengthBytes = SYMMETRIC_KEY_LENGTH);

            protected:
                CryptoBuffer m_key;
                CryptoBuffer m_initializationVector;
                CryptoBuffer m_tag;
                bool m_failure;

            private:
                void Validate();
            };

            class SymmetricCipherFactory
            {
            public:
                virtual ~SymmetricCipherFactory() {}

                virtual std::shared_ptr<SymmetricCipher> CreateImplementation(const CryptoBuffer& key) const = 0;
                virtual std::shared_ptr<SymmetricCipher> CreateImplementation(const CryptoBuffer& key, const CryptoBuffer& iv, const CryptoBuffer& tag = CryptoBuffer(0)) const = 0;
                virtual std::shared_ptr<SymmetricCipher> CreateImplementation(CryptoBuffer&& key, CryptoBuffer&& iv, CryptoBuffer&& tag = CryptoBuffer(0)) const = 0;

                virtual void InitStaticState() {}

                virtual void CleanupStaticState() {}
            };
        }
    }
}