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AuthenticatedSymmetricCipherBase Class Referenceabstract

Base class for authenticated encryption modes of operation. More...

#include <authenc.h>

Inheritance diagram for AuthenticatedSymmetricCipherBase:
AuthenticatedSymmetricCipher MessageAuthenticationCode StreamTransformation SimpleKeyingInterface HashTransformation Algorithm Algorithm Clonable Clonable CCM_Base ChaCha20Poly1305_Base EAX_Base GCM_Base XChaCha20Poly1305_Base CCM_Final< T_BlockCipher, T_DefaultDigestSize, T_IsEncryption > ChaCha20Poly1305_Final< T_IsEncryption > EAX_Final< T_BlockCipher, T_IsEncryption > GCM_Final< T_BlockCipher, T_TablesOption, T_IsEncryption > XChaCha20Poly1305_Final< T_IsEncryption >

Public Member Functions

bool IsRandomAccess () const
 Determines whether the cipher supports random access.
 
bool IsSelfInverting () const
 Determines whether the cipher is self-inverting.
 
void SetKey (const byte *userKey, size_t keylength, const NameValuePairs &params)
 Sets or reset the key of this object.
 
void Restart ()
 Restart the hash.
 
void Resynchronize (const byte *iv, int length=-1)
 Resynchronize with an IV.
 
void Update (const byte *input, size_t length)
 Updates a hash with additional input.
 
void ProcessData (byte *outString, const byte *inString, size_t length)
 Encrypt or decrypt an array of bytes.
 
void TruncatedFinal (byte *mac, size_t macSize)
 Computes the hash of the current message.
 
- Public Member Functions inherited from AuthenticatedSymmetricCipher
virtual lword MaxHeaderLength () const =0
 Provides the maximum length of AAD that can be input.
 
virtual lword MaxMessageLength () const =0
 Provides the maximum length of encrypted data.
 
virtual lword MaxFooterLength () const
 Provides the maximum length of AAD.
 
virtual bool NeedsPrespecifiedDataLengths () const
 Determines if data lengths must be specified prior to inputting data.
 
void SpecifyDataLengths (lword headerLength, lword messageLength, lword footerLength=0)
 Prescribes the data lengths.
 
virtual void EncryptAndAuthenticate (byte *ciphertext, byte *mac, size_t macSize, const byte *iv, int ivLength, const byte *header, size_t headerLength, const byte *message, size_t messageLength)
 Encrypts and calculates a MAC in one call.
 
virtual bool DecryptAndVerify (byte *message, const byte *mac, size_t macSize, const byte *iv, int ivLength, const byte *header, size_t headerLength, const byte *ciphertext, size_t ciphertextLength)
 Decrypts and verifies a MAC in one call.
 
virtual std::string AlgorithmName () const
 Provides the name of this algorithm.
 
virtual std::string AlgorithmProvider () const
 Retrieve the provider of this algorithm.
 
- Public Member Functions inherited from SimpleKeyingInterface
virtual size_t MinKeyLength () const =0
 Returns smallest valid key length.
 
virtual size_t MaxKeyLength () const =0
 Returns largest valid key length.
 
virtual size_t DefaultKeyLength () const =0
 Returns default key length.
 
virtual size_t GetValidKeyLength (size_t keylength) const =0
 Returns a valid key length for the algorithm.
 
virtual bool IsValidKeyLength (size_t keylength) const
 Returns whether keylength is a valid key length.
 
void SetKeyWithRounds (const byte *key, size_t length, int rounds)
 Sets or reset the key of this object.
 
void SetKeyWithIV (const byte *key, size_t length, const byte *iv, size_t ivLength)
 Sets or reset the key of this object.
 
void SetKeyWithIV (const byte *key, size_t length, const byte *iv)
 Sets or reset the key of this object.
 
virtual IV_Requirement IVRequirement () const =0
 Minimal requirement for secure IVs.
 
bool IsResynchronizable () const
 Determines if the object can be resynchronized.
 
bool CanUseRandomIVs () const
 Determines if the object can use random IVs.
 
bool CanUsePredictableIVs () const
 Determines if the object can use random but possibly predictable IVs.
 
bool CanUseStructuredIVs () const
 Determines if the object can use structured IVs.
 
virtual unsigned int IVSize () const
 Returns length of the IV accepted by this object.
 
unsigned int DefaultIVLength () const
 Provides the default size of an IV.
 
virtual unsigned int MinIVLength () const
 Provides the minimum size of an IV.
 
virtual unsigned int MaxIVLength () const
 Provides the maximum size of an IV.
 
virtual void GetNextIV (RandomNumberGenerator &rng, byte *iv)
 Retrieves a secure IV for the next message.
 
- Public Member Functions inherited from HashTransformation
HashTransformationRef ()
 Provides a reference to this object.
 
virtual byteCreateUpdateSpace (size_t &size)
 Request space which can be written into by the caller.
 
virtual void Final (byte *digest)
 Computes the hash of the current message.
 
virtual unsigned int DigestSize () const =0
 
unsigned int TagSize () const
 
virtual unsigned int BlockSize () const
 Provides the block size of the compression function.
 
virtual unsigned int OptimalBlockSize () const
 Provides the input block size most efficient for this hash.
 
virtual unsigned int OptimalDataAlignment () const
 Provides input and output data alignment for optimal performance.
 
virtual void CalculateDigest (byte *digest, const byte *input, size_t length)
 Updates the hash with additional input and computes the hash of the current message.
 
virtual bool Verify (const byte *digest)
 Verifies the hash of the current message.
 
virtual bool VerifyDigest (const byte *digest, const byte *input, size_t length)
 Updates the hash with additional input and verifies the hash of the current message.
 
virtual void CalculateTruncatedDigest (byte *digest, size_t digestSize, const byte *input, size_t length)
 Updates the hash with additional input and computes the hash of the current message.
 
virtual bool TruncatedVerify (const byte *digest, size_t digestLength)
 Verifies the hash of the current message.
 
virtual bool VerifyTruncatedDigest (const byte *digest, size_t digestLength, const byte *input, size_t length)
 Updates the hash with additional input and verifies the hash of the current message.
 
- Public Member Functions inherited from Algorithm
 Algorithm (bool checkSelfTestStatus=true)
 Interface for all crypto algorithms.
 
- Public Member Functions inherited from Clonable
virtual ClonableClone () const
 Copies this object.
 
- Public Member Functions inherited from StreamTransformation
StreamTransformationRef ()
 Provides a reference to this object.
 
virtual unsigned int MandatoryBlockSize () const
 Provides the mandatory block size of the cipher.
 
virtual unsigned int OptimalBlockSize () const
 Provides the input block size most efficient for this cipher.
 
virtual unsigned int GetOptimalBlockSizeUsed () const
 Provides the number of bytes used in the current block when processing at optimal block size.
 
virtual unsigned int OptimalDataAlignment () const
 Provides input and output data alignment for optimal performance.
 
virtual size_t ProcessLastBlock (byte *outString, size_t outLength, const byte *inString, size_t inLength)
 Encrypt or decrypt the last block of data.
 
virtual unsigned int MinLastBlockSize () const
 Provides the size of the last block.
 
virtual bool IsLastBlockSpecial () const
 Determines if the last block receives special processing.
 
void ProcessString (byte *inoutString, size_t length)
 Encrypt or decrypt a string of bytes.
 
void ProcessString (byte *outString, const byte *inString, size_t length)
 Encrypt or decrypt a string of bytes.
 
byte ProcessByte (byte input)
 Encrypt or decrypt a byte.
 
virtual void Seek (lword pos)
 Seek to an absolute position.
 
virtual bool IsForwardTransformation () const =0
 Determines if the cipher is being operated in its forward direction.
 

Protected Types

enum  State {
  State_Start , State_KeySet , State_IVSet , State_AuthUntransformed ,
  State_AuthTransformed , State_AuthFooter
}
 

Protected Member Functions

void UncheckedSetKey (const byte *key, unsigned int length, const CryptoPP::NameValuePairs &params)
 
void AuthenticateData (const byte *data, size_t len)
 
const SymmetricCipherGetSymmetricCipher () const
 
virtual SymmetricCipherAccessSymmetricCipher ()=0
 
virtual bool AuthenticationIsOnPlaintext () const =0
 
virtual unsigned int AuthenticationBlockSize () const =0
 
virtual void SetKeyWithoutResync (const byte *userKey, size_t keylength, const NameValuePairs &params)=0
 
virtual void Resync (const byte *iv, size_t len)=0
 
virtual size_t AuthenticateBlocks (const byte *data, size_t len)=0
 
virtual void AuthenticateLastHeaderBlock ()=0
 
virtual void AuthenticateLastConfidentialBlock ()
 
virtual void AuthenticateLastFooterBlock (byte *mac, size_t macSize)=0
 
- Protected Member Functions inherited from AuthenticatedSymmetricCipher
const AlgorithmGetAlgorithm () const
 Returns the base class Algorithm.
 
virtual void UncheckedSpecifyDataLengths (lword headerLength, lword messageLength, lword footerLength)
 
- Protected Member Functions inherited from MessageAuthenticationCode
const AlgorithmGetAlgorithm () const
 Returns the base class Algorithm.
 
- Protected Member Functions inherited from SimpleKeyingInterface
virtual void UncheckedSetKey (const byte *key, unsigned int length, const NameValuePairs &params)=0
 Sets the key for this object without performing parameter validation.
 
void ThrowIfInvalidKeyLength (size_t length)
 Validates the key length.
 
void ThrowIfResynchronizable ()
 Validates the object.
 
void ThrowIfInvalidIV (const byte *iv)
 Validates the IV.
 
size_t ThrowIfInvalidIVLength (int length)
 Validates the IV length.
 
const byteGetIVAndThrowIfInvalid (const NameValuePairs &params, size_t &size)
 Retrieves and validates the IV.
 
void AssertValidKeyLength (size_t length) const
 Validates the key length.
 
- Protected Member Functions inherited from HashTransformation
void ThrowIfInvalidTruncatedSize (size_t size) const
 Validates a truncated digest size.
 

Protected Attributes

AlignedSecByteBlock m_buffer
 
lword m_totalHeaderLength
 
lword m_totalMessageLength
 
lword m_totalFooterLength
 
unsigned int m_bufferedDataLength
 
State m_state
 

Additional Inherited Members

- Public Types inherited from SimpleKeyingInterface
enum  IV_Requirement {
  UNIQUE_IV = 0 , RANDOM_IV , UNPREDICTABLE_RANDOM_IV , INTERNALLY_GENERATED_IV ,
  NOT_RESYNCHRONIZABLE
}
 Secure IVs requirements as enumerated values. More...
 

Detailed Description

Base class for authenticated encryption modes of operation.

AuthenticatedSymmetricCipherBase() serves as a base implementation for one direction (encryption or decryption) of a stream cipher or block cipher mode with authentication.

Crypto++ provides four authenticated encryption modes of operation - CCM, EAX, GCM and OCB mode. All modes derive from AuthenticatedSymmetricCipherBase() and the motivation for the API, like calling AAD a "header", can be found in Bellare, Rogaway and Wagner's The EAX Mode of Operation. The EAX paper suggested a basic API to help standardize AEAD schemes in software and promote adoption of the modes.

See also
Authenticated Encryption on the Crypto++ wiki.
Since
Crypto++ 5.6.0

Definition at line 40 of file authenc.h.

Member Enumeration Documentation

◆ State

enum AuthenticatedSymmetricCipherBase::State
protected

Definition at line 77 of file authenc.h.

Constructor & Destructor Documentation

◆ AuthenticatedSymmetricCipherBase()

AuthenticatedSymmetricCipherBase::AuthenticatedSymmetricCipherBase ( )
inline

Definition at line 43 of file authenc.h.

Member Function Documentation

◆ AuthenticateData()

void AuthenticatedSymmetricCipherBase::AuthenticateData ( const byte data,
size_t  len 
)
protected

Definition at line 11 of file authenc.cpp.

◆ AuthenticateLastConfidentialBlock()

virtual void AuthenticatedSymmetricCipherBase::AuthenticateLastConfidentialBlock ( )
inlineprotectedvirtual

Definition at line 72 of file authenc.h.

◆ GetSymmetricCipher()

const SymmetricCipher & AuthenticatedSymmetricCipherBase::GetSymmetricCipher ( ) const
inlineprotected

Definition at line 62 of file authenc.h.

◆ IsRandomAccess()

bool AuthenticatedSymmetricCipherBase::IsRandomAccess ( ) const
inlinevirtual

Determines whether the cipher supports random access.

Returns
true if the cipher supports random access, false otherwise

Implements StreamTransformation.

Definition at line 47 of file authenc.h.

◆ IsSelfInverting()

bool AuthenticatedSymmetricCipherBase::IsSelfInverting ( ) const
inlinevirtual

Determines whether the cipher is self-inverting.

Returns
true if the cipher is self-inverting, false otherwise

IsSelfInverting determines whether this transformation is self-inverting (e.g. xor with a keystream).

Implements StreamTransformation.

Definition at line 48 of file authenc.h.

◆ ProcessData()

void AuthenticatedSymmetricCipherBase::ProcessData ( byte outString,
const byte inString,
size_t  length 
)
virtual

Encrypt or decrypt an array of bytes.

Parameters
outStringthe output byte buffer
inStringthe input byte buffer
lengththe size of the input and output byte buffers, in bytes

ProcessData is called with a string of bytes whose size depends on MandatoryBlockSize. Either inString == outString, or they must not overlap.

See also
ProcessData, ProcessLastBlock, MandatoryBlockSize, MinLastBlockSize, BlockPaddingSchemeDef, IsLastBlockSpecial

Implements StreamTransformation.

Definition at line 109 of file authenc.cpp.

◆ Restart()

void AuthenticatedSymmetricCipherBase::Restart ( )
inlinevirtual

Restart the hash.

Discards the current state, and restart for a new message

Reimplemented from HashTransformation.

Definition at line 51 of file authenc.h.

◆ Resynchronize()

void AuthenticatedSymmetricCipherBase::Resynchronize ( const byte iv,
int  ivLength = -1 
)
virtual

Resynchronize with an IV.

Parameters
ivthe initialization vector
ivLengththe size of the initialization vector, in bytes

Resynchronize() resynchronizes with an IV provided by the caller. ivLength=-1 means use IVSize().

Exceptions
NotImplemented()if the object does not support resynchronization

Reimplemented from SimpleKeyingInterface.

Definition at line 67 of file authenc.cpp.

◆ SetKey()

void AuthenticatedSymmetricCipherBase::SetKey ( const byte key,
size_t  length,
const NameValuePairs params 
)
virtual

Sets or reset the key of this object.

Parameters
keythe key to use when keying the object
lengththe size of the key, in bytes
paramsadditional initialization parameters to configure this object

Reimplemented from SimpleKeyingInterface.

Definition at line 53 of file authenc.cpp.

◆ TruncatedFinal()

void AuthenticatedSymmetricCipherBase::TruncatedFinal ( byte digest,
size_t  digestSize 
)
virtual

Computes the hash of the current message.

Parameters
digesta pointer to the buffer to receive the hash
digestSizethe size of the truncated digest, in bytes

TruncatedFinal() calls Final() and then copies digestSize bytes to digest. The hash is restarted the hash for the next message.

Precondition
COUNTOF(digest) <= DigestSize() or COUNTOF(digest) <= HASH::DIGESTSIZE ensures the output byte buffer is a valid size.

Implements HashTransformation.

Definition at line 141 of file authenc.cpp.

◆ UncheckedSetKey()

void AuthenticatedSymmetricCipherBase::UncheckedSetKey ( const byte key,
unsigned int  length,
const CryptoPP::NameValuePairs &  params 
)
inlineprotected

Definition at line 58 of file authenc.h.

◆ Update()

void AuthenticatedSymmetricCipherBase::Update ( const byte input,
size_t  length 
)
virtual

Updates a hash with additional input.

Parameters
inputthe additional input as a buffer
lengththe size of the buffer, in bytes

Implements HashTransformation.

Definition at line 80 of file authenc.cpp.

Member Data Documentation

◆ m_buffer

AlignedSecByteBlock AuthenticatedSymmetricCipherBase::m_buffer
protected

Definition at line 79 of file authenc.h.

◆ m_bufferedDataLength

unsigned int AuthenticatedSymmetricCipherBase::m_bufferedDataLength
protected

Definition at line 81 of file authenc.h.

◆ m_state

State AuthenticatedSymmetricCipherBase::m_state
protected

Definition at line 82 of file authenc.h.

◆ m_totalFooterLength

lword AuthenticatedSymmetricCipherBase::m_totalFooterLength
protected

Definition at line 80 of file authenc.h.

◆ m_totalHeaderLength

lword AuthenticatedSymmetricCipherBase::m_totalHeaderLength
protected

Definition at line 80 of file authenc.h.

◆ m_totalMessageLength

lword AuthenticatedSymmetricCipherBase::m_totalMessageLength
protected

Definition at line 80 of file authenc.h.


The documentation for this class was generated from the following files: