JUCE/modules/juce_cryptography/encryption/juce_BlowFish.h

/*
  ==============================================================================

   This file is part of the JUCE library.
   Copyright (c) 2015 - ROLI Ltd.

   Permission is granted to use this software under the terms of either:
   a) the GPL v2 (or any later version)
   b) the Affero GPL v3

   Details of these licenses can be found at: www.gnu.org/licenses

   JUCE 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.

   ------------------------------------------------------------------------------

   To release a closed-source product which uses JUCE, commercial licenses are
   available: visit www.juce.com for more information.

  ==============================================================================
*/

#ifndef JUCE_BLOWFISH_H_INCLUDED
#define JUCE_BLOWFISH_H_INCLUDED


//==============================================================================
/**
    BlowFish encryption class.

*/
class JUCE_API  BlowFish
{
public:
    //==============================================================================
    /** Creates an object that can encode/decode based on the specified key.

        The key data can be up to 72 bytes long.
    */
    BlowFish (const void* keyData, int keyBytes);

    /** Creates a copy of another blowfish object. */
    BlowFish (const BlowFish&);

    /** Copies another blowfish object. */
    BlowFish& operator= (const BlowFish&) noexcept;

    /** Destructor. */
    ~BlowFish() noexcept;

    //==============================================================================
    /** Encrypts a pair of 32-bit integers. */
    void encrypt (uint32& data1, uint32& data2) const noexcept;

    /** Decrypts a pair of 32-bit integers. */
    void decrypt (uint32& data1, uint32& data2) const noexcept;

    //==============================================================================
    /** Encrypts a memory block */
    void encrypt (MemoryBlock& data) const;

    /** Decrypts a memory block */
    void decrypt (MemoryBlock& data) const;

    //==============================================================================
    /** Encrypts data in-place

        @param buffer       The message that should be encrypted. See bufferSize on size
                            requirements!
        @param sizeOfMsg    The size of the message that should be encrypted in bytes
        @param bufferSize   The size of the buffer in bytes. To accomadate the encypted
                            data, the buffer must be larger than the message: the size of
                            the buffer needs to be equal or greater than the size of the
                            message in bytes rounded to the next integer which is divisable
                            by eight. If the message size in bytes is already divisable by eight
                            then you need to add eight bytes to the buffer size. If in doubt
                            simply use bufferSize = sizeOfMsg + 8.

        @returns            The size of the decrypted data in bytes or -1 if the decryption failed.
     */
    int encrypt (void* buffer, size_t sizeOfMsg, size_t bufferSize) const noexcept;

    /** Decrypts data in-place

        @param buffer  The encrypted data that should be decrypted
        @param bytes   The size of the encrypted data in bytes

        @returns       The size of the decrypted data in bytes or -1 if the decryption failed.
    */
    int decrypt (void* buffer, size_t bytes) const noexcept;

private:
    //==============================================================================
    static int pad   (void*, size_t, size_t) noexcept;
    static int unpad (const void*, size_t) noexcept;

    bool apply (void*, size_t, void (BlowFish::*op) (uint32&, uint32&) const noexcept) const;

    //==============================================================================
    uint32 p[18];
    HeapBlock<uint32> s[4];

    uint32 F (uint32) const noexcept;

    JUCE_LEAK_DETECTOR (BlowFish)
};


#endif   // JUCE_BLOWFISH_H_INCLUDED