source: box/trunk/lib/crypto/CipherContext.h @ 3098

// --------------------------------------------------------------------------
//
// File
//              Name:    CipherContext.h
//              Purpose: Context for symmetric encryption / descryption
//              Created: 1/12/03
//
// --------------------------------------------------------------------------

#ifndef CIPHERCONTEXT__H
#define CIPHERCONTEXT__H

#ifdef BOX_LIB_CRYPTO_OPENSSL_HEADERS_INCLUDED_FALSE
        always include CipherContext.h first in any .cpp file
#endif
#define BOX_LIB_CRYPTO_OPENSSL_HEADERS_INCLUDED_TRUE
#include <openssl/evp.h>
class CipherDescription;

#define CIPHERCONTEXT_MAX_GENERATED_IV_LENGTH           32

// --------------------------------------------------------------------------
//
// Class
//              Name:    CipherContext
//              Purpose: Context for symmetric encryption / descryption
//              Created: 1/12/03
//
// --------------------------------------------------------------------------
class CipherContext
{
public:
        CipherContext();
        ~CipherContext();
private:
        CipherContext(const CipherContext &);   // no copying
        CipherContext &operator=(const CipherContext &);        // no assignment
protected:
        std::string LogError(const std::string& operation);
public:

        typedef enum
        {
                None = 0,
                Decrypt,
                Encrypt
        } CipherFunction;

        void Init(CipherContext::CipherFunction Function, const CipherDescription &rDescription);
        void Reset();
        
        void Begin();
        int Transform(void *pOutBuffer, int OutLength, const void *pInBuffer, int InLength);
        int Final(void *pOutBuffer, int OutLength);
        int InSizeForOutBufferSize(int OutLength);
        int MaxOutSizeForInBufferSize(int InLength);
        
        int TransformBlock(void *pOutBuffer, int OutLength, const void *pInBuffer, int InLength);

        bool IsInitialised() {return mInitialised;}
        
        int GetIVLength();
        void SetIV(const void *pIV);
        const void *SetRandomIV(int &rLengthOut);
        
        void UsePadding(bool Padding = true);
        const char* GetFunction() const
        {
                return (mFunction == Encrypt) ? "encrypt" : "decrypt";
        }

#ifdef HAVE_OLD_SSL
        void OldOpenSSLFinal(unsigned char *Buffer, int &rOutLengthOut);
#endif
        
private:
        EVP_CIPHER_CTX ctx;
        bool mInitialised;
        bool mWithinTransform;
        bool mPaddingOn;
        uint8_t mGeneratedIV[CIPHERCONTEXT_MAX_GENERATED_IV_LENGTH];
        CipherFunction mFunction;
        std::string mCipherName;
#ifdef HAVE_OLD_SSL
        CipherDescription *mpDescription;
#endif
};


#endif // CIPHERCONTEXT__H