Crypto++  5.6.4
Free C++ class library of cryptographic schemes
authenc.h
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1 // authenc.h - written and placed in the public domain by Wei Dai
2 
3 //! \file
4 //! \headerfile authenc.h
5 //! \brief Base classes for working with authenticated encryption modes of encryption
6 //! \since Crypto++ 5.6.0
7 
8 #ifndef CRYPTOPP_AUTHENC_H
9 #define CRYPTOPP_AUTHENC_H
10 
11 #include "cryptlib.h"
12 #include "secblock.h"
13 
14 NAMESPACE_BEGIN(CryptoPP)
15 
16 //! \class AuthenticatedSymmetricCipherBase
17 //! \brief Base implementation for one direction (encryption or decryption) of a stream cipher or block cipher mode with authentication
18 //! \since Crypto++ 5.6.0
19 class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE AuthenticatedSymmetricCipherBase : public AuthenticatedSymmetricCipher
20 {
21 public:
22  AuthenticatedSymmetricCipherBase() : m_state(State_Start), m_bufferedDataLength(0),
23  m_totalHeaderLength(0), m_totalMessageLength(0), m_totalFooterLength(0) {}
24 
25  bool IsRandomAccess() const {return false;}
26  bool IsSelfInverting() const {return true;}
27 
28  //! \brief Sets the key for this object without performing parameter validation
29  //! \param key a byte buffer used to key the cipher
30  //! \param length the length of the byte buffer
31  //! \param params additional parameters passed as NameValuePairs
32  //! \details key must be at least DEFAULT_KEYLENGTH in length.
33  void UncheckedSetKey(const byte * key, unsigned int length,const CryptoPP::NameValuePairs &params)
34  {CRYPTOPP_UNUSED(key), CRYPTOPP_UNUSED(length), CRYPTOPP_UNUSED(params); CRYPTOPP_ASSERT(false);}
35 
36  void SetKey(const byte *userKey, size_t keylength, const NameValuePairs &params);
37  void Restart() {if (m_state > State_KeySet) m_state = State_KeySet;}
38  void Resynchronize(const byte *iv, int length=-1);
39  void Update(const byte *input, size_t length);
40  void ProcessData(byte *outString, const byte *inString, size_t length);
41  void TruncatedFinal(byte *mac, size_t macSize);
42 
43 protected:
44  void AuthenticateData(const byte *data, size_t len);
45  const SymmetricCipher & GetSymmetricCipher() const {return const_cast<AuthenticatedSymmetricCipherBase *>(this)->AccessSymmetricCipher();};
46 
47  virtual SymmetricCipher & AccessSymmetricCipher() =0;
48  virtual bool AuthenticationIsOnPlaintext() const =0;
49  virtual unsigned int AuthenticationBlockSize() const =0;
50  virtual void SetKeyWithoutResync(const byte *userKey, size_t keylength, const NameValuePairs &params) =0;
51  virtual void Resync(const byte *iv, size_t len) =0;
52  virtual size_t AuthenticateBlocks(const byte *data, size_t len) =0;
53  virtual void AuthenticateLastHeaderBlock() =0;
54  virtual void AuthenticateLastConfidentialBlock() {}
55  virtual void AuthenticateLastFooterBlock(byte *mac, size_t macSize) =0;
56 
57  enum State {State_Start, State_KeySet, State_IVSet, State_AuthUntransformed, State_AuthTransformed, State_AuthFooter};
58  State m_state;
59  unsigned int m_bufferedDataLength;
60  lword m_totalHeaderLength, m_totalMessageLength, m_totalFooterLength;
61  AlignedSecByteBlock m_buffer;
62 };
63 
64 NAMESPACE_END
65 
66 #endif
Interface for one direction (encryption or decryption) of a stream cipher or block cipher mode with a...
Definition: cryptlib.h:1124
void UncheckedSetKey(const byte *key, unsigned int length, const ::NameValuePairs &params)
Sets the key for this object without performing parameter validation.
Definition: authenc.h:33
Abstract base classes that provide a uniform interface to this library.
bool IsRandomAccess() const
Determines whether the cipher supports random access.
Definition: authenc.h:25
void Restart()
Restart the hash.
Definition: authenc.h:37
Classes and functions for secure memory allocations.
Interface for one direction (encryption or decryption) of a stream cipher or cipher mode...
Definition: cryptlib.h:1106
Base implementation for one direction (encryption or decryption) of a stream cipher or block cipher m...
Definition: authenc.h:19
SecBlock using AllocatorWithCleanup typedef.
Definition: secblock.h:737
#define CRYPTOPP_ASSERT(exp)
Debugging and diagnostic assertion.
Definition: trap.h:62
bool IsSelfInverting() const
Determines whether the cipher is self-inverting.
Definition: authenc.h:26
Crypto++ library namespace.
Interface for retrieving values given their names.
Definition: cryptlib.h:282