chachapoly.h

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// chachapoly.h - written and placed in the public domain by Jeffrey Walton
//                RFC 8439, Section 2.8, AEAD Construction, http://tools.ietf.org/html/rfc8439
 
 
#ifndef CRYPTOPP_CHACHA_POLY1305_H
#define CRYPTOPP_CHACHA_POLY1305_H
 
#include "cryptlib.h"
#include "authenc.h"
#include "chacha.h"
#include "poly1305.h"
 
NAMESPACE_BEGIN(CryptoPP)
 
 
 
 
class ChaCha20Poly1305_Base : public AuthenticatedSymmetricCipherBase
{
public:
        CRYPTOPP_STATIC_CONSTEXPR const char* StaticAlgorithmName()
                {return "ChaCha20/Poly1305";}
 
        virtual ~ChaCha20Poly1305_Base() {}
 
        // AuthenticatedSymmetricCipher
        std::string AlgorithmName() const
                {return std::string("ChaCha20/Poly1305");}
        std::string AlgorithmProvider() const
                {return GetSymmetricCipher().AlgorithmProvider();}
        size_t MinKeyLength() const
                {return 32;}
        size_t MaxKeyLength() const
                {return 32;}
        size_t DefaultKeyLength() const
                {return 32;}
        size_t GetValidKeyLength(size_t n) const
                {CRYPTOPP_UNUSED(n); return 32;}
        bool IsValidKeyLength(size_t n) const
                {return n==32;}
        unsigned int OptimalDataAlignment() const
                {return GetSymmetricCipher().OptimalDataAlignment();}
        IV_Requirement IVRequirement() const
                {return UNIQUE_IV;}
        unsigned int IVSize() const
                {return 12;}
        unsigned int MinIVLength() const
                {return 12;}
        unsigned int MaxIVLength() const
                {return 12;}
        unsigned int DigestSize() const
                {return 16;}
        lword MaxHeaderLength() const
                {return LWORD_MAX;}  // 2^64-1 bytes
        lword MaxMessageLength() const
                {return W64LIT(274877906880);}  // 2^38-1 blocks
        lword MaxFooterLength() const
                {return 0;}
 
        virtual void EncryptAndAuthenticate(byte *ciphertext, byte *mac, size_t macSize, const byte *iv, int ivLength, const byte *aad, size_t aadLength, const byte *message, size_t messageLength);
 
        virtual bool DecryptAndVerify(byte *message, const byte *mac, size_t macSize, const byte *iv, int ivLength, const byte *aad, size_t aadLength, const byte *ciphertext, size_t ciphertextLength);
 
protected:
        // AuthenticatedSymmetricCipherBase
        bool AuthenticationIsOnPlaintext() const {return false;}
        unsigned int AuthenticationBlockSize() const {return 1;}
        void SetKeyWithoutResync(const byte *userKey, size_t keylength, const NameValuePairs &params);
        void Resync(const byte *iv, size_t len);
        size_t AuthenticateBlocks(const byte *data, size_t len);
        void AuthenticateLastHeaderBlock();
        void AuthenticateLastConfidentialBlock();
        void AuthenticateLastFooterBlock(byte *mac, size_t macSize);
 
        // See comments in chachapoly.cpp
        void RekeyCipherAndMac(const byte *userKey, size_t userKeyLength, const NameValuePairs &params);
 
        virtual const MessageAuthenticationCode & GetMAC() const = 0;
        virtual MessageAuthenticationCode & AccessMAC() = 0;
 
private:
        SecByteBlock m_userKey;
};
 
template <bool T_IsEncryption>
class ChaCha20Poly1305_Final : public ChaCha20Poly1305_Base
{
public:
        virtual ~ChaCha20Poly1305_Final() {}
 
protected:
        const SymmetricCipher & GetSymmetricCipher()
                {return const_cast<ChaCha20Poly1305_Final *>(this)->AccessSymmetricCipher();}
        SymmetricCipher & AccessSymmetricCipher()
                {return m_cipher;}
        bool IsForwardTransformation() const
                {return T_IsEncryption;}
 
        const MessageAuthenticationCode & GetMAC() const
                {return const_cast<ChaCha20Poly1305_Final *>(this)->AccessMAC();}
        MessageAuthenticationCode & AccessMAC()
                {return m_mac;}
 
private:
        ChaChaTLS::Encryption m_cipher;
        Poly1305TLS m_mac;
};
 
struct ChaCha20Poly1305 : public AuthenticatedSymmetricCipherDocumentation
{
        typedef ChaCha20Poly1305_Final<true> Encryption;
        typedef ChaCha20Poly1305_Final<false> Decryption;
};
 
 
class XChaCha20Poly1305_Base : public AuthenticatedSymmetricCipherBase
{
public:
        CRYPTOPP_STATIC_CONSTEXPR const char* StaticAlgorithmName()
                {return "XChaCha20/Poly1305";}
 
        virtual ~XChaCha20Poly1305_Base() {}
 
        // AuthenticatedSymmetricCipher
        std::string AlgorithmName() const
                {return std::string("XChaCha20/Poly1305");}
        std::string AlgorithmProvider() const
                {return GetSymmetricCipher().AlgorithmProvider();}
        size_t MinKeyLength() const
                {return 32;}
        size_t MaxKeyLength() const
                {return 32;}
        size_t DefaultKeyLength() const
                {return 32;}
        size_t GetValidKeyLength(size_t n) const
                {CRYPTOPP_UNUSED(n); return 32;}
        bool IsValidKeyLength(size_t n) const
                {return n==32;}
        unsigned int OptimalDataAlignment() const
                {return GetSymmetricCipher().OptimalDataAlignment();}
        IV_Requirement IVRequirement() const
                {return UNIQUE_IV;}
        unsigned int IVSize() const
                {return 24;}
        unsigned int MinIVLength() const
                {return 24;}
        unsigned int MaxIVLength() const
                {return 24;}
        unsigned int DigestSize() const
                {return 16;}
        lword MaxHeaderLength() const
                {return LWORD_MAX;}  // 2^64-1 bytes
        lword MaxMessageLength() const
                {return W64LIT(274877906880);}  // 2^38-1 blocks
        lword MaxFooterLength() const
                {return 0;}
 
        virtual void EncryptAndAuthenticate(byte *ciphertext, byte *mac, size_t macSize, const byte *iv, int ivLength, const byte *aad, size_t aadLength, const byte *message, size_t messageLength);
 
        virtual bool DecryptAndVerify(byte *message, const byte *mac, size_t macSize, const byte *iv, int ivLength, const byte *aad, size_t aadLength, const byte *ciphertext, size_t ciphertextLength);
 
protected:
        // AuthenticatedSymmetricCipherBase
        bool AuthenticationIsOnPlaintext() const {return false;}
        unsigned int AuthenticationBlockSize() const {return 1;}
        void SetKeyWithoutResync(const byte *userKey, size_t keylength, const NameValuePairs &params);
        void Resync(const byte *iv, size_t len);
        size_t AuthenticateBlocks(const byte *data, size_t len);
        void AuthenticateLastHeaderBlock();
        void AuthenticateLastConfidentialBlock();
        void AuthenticateLastFooterBlock(byte *mac, size_t macSize);
 
        // See comments in chachapoly.cpp
        void RekeyCipherAndMac(const byte *userKey, size_t userKeyLength, const NameValuePairs &params);
 
        virtual const MessageAuthenticationCode & GetMAC() const = 0;
        virtual MessageAuthenticationCode & AccessMAC() = 0;
 
private:
        SecByteBlock m_userKey;
};
 
template <bool T_IsEncryption>
class XChaCha20Poly1305_Final : public XChaCha20Poly1305_Base
{
public:
        virtual ~XChaCha20Poly1305_Final() {}
 
protected:
        const SymmetricCipher & GetSymmetricCipher()
                {return const_cast<XChaCha20Poly1305_Final *>(this)->AccessSymmetricCipher();}
        SymmetricCipher & AccessSymmetricCipher()
                {return m_cipher;}
        bool IsForwardTransformation() const
                {return T_IsEncryption;}
 
        const MessageAuthenticationCode & GetMAC() const
                {return const_cast<XChaCha20Poly1305_Final *>(this)->AccessMAC();}
        MessageAuthenticationCode & AccessMAC()
                {return m_mac;}
 
private:
        XChaCha20::Encryption m_cipher;
        Poly1305TLS m_mac;
};
 
struct XChaCha20Poly1305 : public AuthenticatedSymmetricCipherDocumentation
{
        typedef XChaCha20Poly1305_Final<true> Encryption;
        typedef XChaCha20Poly1305_Final<false> Decryption;
};
 
NAMESPACE_END
 
#endif  // CRYPTOPP_CHACHA_POLY1305_H