seckey.h

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// seckey.h - written and placed in the public domain by Wei Dai


#ifndef CRYPTOPP_SECKEY_H
#define CRYPTOPP_SECKEY_H

#include "config.h"
#include "cryptlib.h"
#include "misc.h"
#include "simple.h"

#if CRYPTOPP_MSC_VERSION
# pragma warning(push)
# pragma warning(disable: 4189)
#endif

// Issue 340
#if CRYPTOPP_GCC_DIAGNOSTIC_AVAILABLE
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wconversion"
# pragma GCC diagnostic ignored "-Wsign-conversion"
#endif

NAMESPACE_BEGIN(CryptoPP)

inline CipherDir ReverseCipherDir(CipherDir dir)
{
        return (dir == ENCRYPTION) ? DECRYPTION : ENCRYPTION;
}

template <unsigned int N>
class FixedBlockSize
{
public:
        CRYPTOPP_CONSTANT(BLOCKSIZE = N)
};

// ************** rounds ***************

template <unsigned int R>
class FixedRounds
{
public:
        CRYPTOPP_CONSTANT(ROUNDS = R)
};

template <unsigned int D, unsigned int N=1, unsigned int M=INT_MAX>             // use INT_MAX here because enums are treated as signed ints
class VariableRounds
{
public:
        CRYPTOPP_CONSTANT(DEFAULT_ROUNDS = D)
        CRYPTOPP_CONSTANT(MIN_ROUNDS = N)
        CRYPTOPP_CONSTANT(MAX_ROUNDS = M)
        CRYPTOPP_STATIC_CONSTEXPR unsigned int StaticGetDefaultRounds(size_t keylength)
        {
                return CRYPTOPP_UNUSED(keylength), static_cast<unsigned int>(DEFAULT_ROUNDS);
        }

protected:
        inline void ThrowIfInvalidRounds(int rounds, const Algorithm *alg)
        {
                if (M == INT_MAX) // Coverity and result_independent_of_operands
                {
                        if (rounds < MIN_ROUNDS)
                                throw InvalidRounds(alg ? alg->AlgorithmName() : std::string("VariableRounds"), rounds);
                }
                else
                {
                        if (rounds < MIN_ROUNDS || rounds > MAX_ROUNDS)
                                throw InvalidRounds(alg ? alg->AlgorithmName() : std::string("VariableRounds"), rounds);
                }
        }

        inline unsigned int GetRoundsAndThrowIfInvalid(const NameValuePairs &param, const Algorithm *alg)
        {
                int rounds = param.GetIntValueWithDefault("Rounds", DEFAULT_ROUNDS);
                ThrowIfInvalidRounds(rounds, alg);
                return (unsigned int)rounds;
        }
};

// ************** key length ***************

template <unsigned int N, unsigned int IV_REQ = SimpleKeyingInterface::NOT_RESYNCHRONIZABLE, unsigned int IV_L = 0>
class FixedKeyLength
{
public:
        CRYPTOPP_CONSTANT(KEYLENGTH=N)
        CRYPTOPP_CONSTANT(MIN_KEYLENGTH=N)
        CRYPTOPP_CONSTANT(MAX_KEYLENGTH=N)
        CRYPTOPP_CONSTANT(DEFAULT_KEYLENGTH=N)
        CRYPTOPP_CONSTANT(IV_REQUIREMENT = IV_REQ)
        CRYPTOPP_CONSTANT(IV_LENGTH = IV_L)
        CRYPTOPP_STATIC_CONSTEXPR size_t CRYPTOPP_API StaticGetValidKeyLength(size_t keylength)
        {
                return CRYPTOPP_UNUSED(keylength), static_cast<size_t>(KEYLENGTH);
        }
};

template <unsigned int D, unsigned int N, unsigned int M, unsigned int Q = 1, unsigned int IV_REQ = SimpleKeyingInterface::NOT_RESYNCHRONIZABLE, unsigned int IV_L = 0>
class VariableKeyLength
{
        // Make these private to avoid Doxygen documenting them in all derived classes
        CRYPTOPP_COMPILE_ASSERT(Q > 0);
        CRYPTOPP_COMPILE_ASSERT(N % Q == 0);
        CRYPTOPP_COMPILE_ASSERT(M % Q == 0);
        CRYPTOPP_COMPILE_ASSERT(N < M);
        CRYPTOPP_COMPILE_ASSERT(D >= N);
        CRYPTOPP_COMPILE_ASSERT(M >= D);

public:
        CRYPTOPP_CONSTANT(MIN_KEYLENGTH=N)
        CRYPTOPP_CONSTANT(MAX_KEYLENGTH=M)
        CRYPTOPP_CONSTANT(DEFAULT_KEYLENGTH=D)
        CRYPTOPP_CONSTANT(KEYLENGTH_MULTIPLE=Q)
        CRYPTOPP_CONSTANT(IV_REQUIREMENT=IV_REQ)
        CRYPTOPP_CONSTANT(IV_LENGTH=IV_L)
        CRYPTOPP_STATIC_CONSTEXPR size_t CRYPTOPP_API StaticGetValidKeyLength(size_t keylength)
        {
                return (keylength <= N) ? N :
                        (keylength >= M) ? M :
                        (keylength+Q-1) - (keylength+Q-1)%Q;
        }
};

template <class T, unsigned int IV_REQ = SimpleKeyingInterface::NOT_RESYNCHRONIZABLE, unsigned int IV_L = 0>
class SameKeyLengthAs
{
public:
        CRYPTOPP_CONSTANT(MIN_KEYLENGTH=T::MIN_KEYLENGTH)
        CRYPTOPP_CONSTANT(MAX_KEYLENGTH=T::MAX_KEYLENGTH)
        CRYPTOPP_CONSTANT(DEFAULT_KEYLENGTH=T::DEFAULT_KEYLENGTH)
        CRYPTOPP_CONSTANT(IV_REQUIREMENT=IV_REQ)
        CRYPTOPP_CONSTANT(IV_LENGTH=IV_L)
        CRYPTOPP_STATIC_CONSTEXPR size_t CRYPTOPP_API StaticGetValidKeyLength(size_t keylength)
                {return T::StaticGetValidKeyLength(keylength);}
};

// ************** implementation helper for SimpleKeyingInterface ***************

template <class BASE, class INFO = BASE>
class CRYPTOPP_NO_VTABLE SimpleKeyingInterfaceImpl : public BASE
{
public:
        size_t MinKeyLength() const
                {return INFO::MIN_KEYLENGTH;}

        size_t MaxKeyLength() const
                {return (size_t)INFO::MAX_KEYLENGTH;}

        size_t DefaultKeyLength() const
                {return INFO::DEFAULT_KEYLENGTH;}

        size_t GetValidKeyLength(size_t keylength) const {return INFO::StaticGetValidKeyLength(keylength);}

        SimpleKeyingInterface::IV_Requirement IVRequirement() const
                {return (SimpleKeyingInterface::IV_Requirement)INFO::IV_REQUIREMENT;}

        unsigned int IVSize() const
                {return INFO::IV_LENGTH;}
};

template <class INFO, class BASE = BlockCipher>
class CRYPTOPP_NO_VTABLE BlockCipherImpl : public AlgorithmImpl<SimpleKeyingInterfaceImpl<TwoBases<BASE, INFO> > >
{
public:
        unsigned int BlockSize() const {return this->BLOCKSIZE;}
};

template <CipherDir DIR, class BASE>
class BlockCipherFinal : public ClonableImpl<BlockCipherFinal<DIR, BASE>, BASE>
{
public:
        BlockCipherFinal() {}

        BlockCipherFinal(const byte *key)
                {this->SetKey(key, this->DEFAULT_KEYLENGTH);}

        BlockCipherFinal(const byte *key, size_t length)
                {this->SetKey(key, length);}

        BlockCipherFinal(const byte *key, size_t length, unsigned int rounds)
                {this->SetKeyWithRounds(key, length, rounds);}

        bool IsForwardTransformation() const {return DIR == ENCRYPTION;}
};

template <class BASE, class INFO = BASE>
class MessageAuthenticationCodeImpl : public AlgorithmImpl<SimpleKeyingInterfaceImpl<BASE, INFO>, INFO>
{
};

template <class BASE>
class MessageAuthenticationCodeFinal : public ClonableImpl<MessageAuthenticationCodeFinal<BASE>, MessageAuthenticationCodeImpl<BASE> >
{
public:
        MessageAuthenticationCodeFinal() {}
        MessageAuthenticationCodeFinal(const byte *key)
                {this->SetKey(key, this->DEFAULT_KEYLENGTH);}
        MessageAuthenticationCodeFinal(const byte *key, size_t length)
                {this->SetKey(key, length);}
};

// ************** documentation ***************

struct BlockCipherDocumentation
{
        typedef BlockCipher Encryption;
        typedef BlockCipher Decryption;
};

struct SymmetricCipherDocumentation
{
        typedef SymmetricCipher Encryption;
        typedef SymmetricCipher Decryption;
};

struct AuthenticatedSymmetricCipherDocumentation
{
        typedef AuthenticatedSymmetricCipher Encryption;
        typedef AuthenticatedSymmetricCipher Decryption;
};

NAMESPACE_END

#if CRYPTOPP_MSC_VERSION
# pragma warning(pop)
#endif

// Issue 340
#if CRYPTOPP_GCC_DIAGNOSTIC_AVAILABLE
# pragma GCC diagnostic pop
#endif

#endif