Public Types | Public Member Functions | Protected Types | Protected Member Functions | Protected Attributes

EAX_Base Class Reference

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#include <eax.h>

Inheritance diagram for EAX_Base:
AuthenticatedSymmetricCipherBase AuthenticatedSymmetricCipher MessageAuthenticationCode StreamTransformation SimpleKeyingInterface HashTransformation Algorithm Algorithm Clonable Clonable EAX_Final< T_BlockCipher, T_IsEncryption >

List of all members.

Public Types

enum  IV_Requirement {
  UNIQUE_IV = 0, RANDOM_IV, UNPREDICTABLE_RANDOM_IV, INTERNALLY_GENERATED_IV,
  NOT_RESYNCHRONIZABLE
}

Public Member Functions

std::string AlgorithmName () const
 returns name of this algorithm, not universally implemented yet
size_t MinKeyLength () const
size_t MaxKeyLength () const
size_t DefaultKeyLength () const
size_t GetValidKeyLength (size_t n) const
bool IsValidKeyLength (size_t n) const
unsigned int OptimalDataAlignment () const
 returns how input should be aligned for optimal performance
IV_Requirement IVRequirement () const
unsigned int IVSize () const
unsigned int MinIVLength () const
unsigned int MaxIVLength () const
unsigned int DigestSize () const
lword MaxHeaderLength () const
 the maximum length of AAD that can be input before the encrypted data
lword MaxMessageLength () const
 the maximum length of encrypted data
bool IsRandomAccess () const
 returns whether this cipher supports random access
bool IsSelfInverting () const
 returns whether this transformation is self-inverting (e.g. xor with a keystream)
void UncheckedSetKey (const byte *, unsigned int, const ::NameValuePairs &)
void SetKey (const byte *userKey, size_t keylength, const NameValuePairs &params)
virtual void SetKey (const byte *key, size_t length, const NameValuePairs &params=g_nullNameValuePairs)
 set or reset the key of this object
void Restart ()
virtual void Restart ()
 discard the current state, and restart with a new message
void Resynchronize (const byte *iv, int length=-1)
virtual void Resynchronize (const byte *iv, int ivLength=-1)
 resynchronize with an IV. ivLength=-1 means use IVSize()
void Update (const byte *input, size_t length)
virtual void Update (const byte *input, size_t length)=0
 process more input
void ProcessData (byte *outString, const byte *inString, size_t length)
 encrypt or decrypt an array of bytes of specified length
void TruncatedFinal (byte *mac, size_t macSize)
virtual void TruncatedFinal (byte *digest, size_t digestSize)=0
 truncated version of Final()
virtual lword MaxFooterLength () const
 the maximum length of AAD that can be input after the encrypted data
virtual bool NeedsPrespecifiedDataLengths () const
 if this function returns true, SpecifyDataLengths() must be called before attempting to input data
void SpecifyDataLengths (lword headerLength, lword messageLength, lword footerLength=0)
 this function only needs to be called if NeedsPrespecifiedDataLengths() returns true
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)
 encrypt and generate MAC in one call. will truncate MAC if macSize < TagSize()
virtual bool DecryptAndVerify (byte *message, const byte *mac, size_t macLength, const byte *iv, int ivLength, const byte *header, size_t headerLength, const byte *ciphertext, size_t ciphertextLength)
 decrypt and verify MAC in one call, returning true iff MAC is valid. will assume MAC is truncated if macLength < TagSize()
virtual size_t MinKeyLength () const =0
 returns smallest valid key length in bytes */
virtual size_t MaxKeyLength () const =0
 returns largest valid key length in bytes */
virtual size_t DefaultKeyLength () const =0
 returns default (recommended) key length in bytes */
virtual size_t GetValidKeyLength (size_t n) const =0
 returns the smallest valid key length in bytes that is >= min(n, GetMaxKeyLength())
virtual bool IsValidKeyLength (size_t n) const
 returns whether n is a valid key length
void SetKeyWithRounds (const byte *key, size_t length, int rounds)
 calls SetKey() with an NameValuePairs object that just specifies "Rounds"
void SetKeyWithIV (const byte *key, size_t length, const byte *iv, size_t ivLength)
 calls SetKey() with an NameValuePairs object that just specifies "IV"
void SetKeyWithIV (const byte *key, size_t length, const byte *iv)
 calls SetKey() with an NameValuePairs object that just specifies "IV"
virtual IV_Requirement IVRequirement () const =0
 returns the minimal requirement for secure IVs
bool IsResynchronizable () const
 returns whether this object can be resynchronized (i.e. supports initialization vectors)
bool CanUseRandomIVs () const
 returns whether this object can use random IVs (in addition to ones returned by GetNextIV)
bool CanUsePredictableIVs () const
 returns whether this object can use random but possibly predictable IVs (in addition to ones returned by GetNextIV)
bool CanUseStructuredIVs () const
 returns whether this object can use structured IVs, for example a counter (in addition to ones returned by GetNextIV)
virtual unsigned int IVSize () const
unsigned int DefaultIVLength () const
 returns default length of IVs accepted by this object
virtual unsigned int MinIVLength () const
 returns minimal length of IVs accepted by this object
virtual unsigned int MaxIVLength () const
 returns maximal length of IVs accepted by this object
virtual void GetNextIV (RandomNumberGenerator &rng, byte *IV)
 get a secure IV for the next message
HashTransformation & Ref ()
 return a reference to this object, useful for passing a temporary object to a function that takes a non-const reference
StreamTransformation & Ref ()
 return a reference to this object, useful for passing a temporary object to a function that takes a non-const reference
virtual byte * CreateUpdateSpace (size_t &size)
 request space to write input into
virtual void Final (byte *digest)
 compute hash for current message, then restart for a new message
virtual unsigned int DigestSize () const =0
 size of the hash/digest/MAC returned by Final()
unsigned int TagSize () const
 same as DigestSize()
virtual unsigned int BlockSize () const
 block size of underlying compression function, or 0 if not block based
virtual unsigned int OptimalBlockSize () const
 input to Update() should have length a multiple of this for optimal speed
virtual unsigned int OptimalBlockSize () const
 returns the input block size that is most efficient for this cipher
virtual unsigned int OptimalDataAlignment () const
 returns how input should be aligned for optimal performance
virtual void CalculateDigest (byte *digest, const byte *input, size_t length)
 use this if your input is in one piece and you don't want to call Update() and Final() separately
virtual bool Verify (const byte *digest)
 verify that digest is a valid digest for the current message, then reinitialize the object
virtual bool VerifyDigest (const byte *digest, const byte *input, size_t length)
 use this if your input is in one piece and you don't want to call Update() and Verify() separately
virtual void CalculateTruncatedDigest (byte *digest, size_t digestSize, const byte *input, size_t length)
 truncated version of CalculateDigest()
virtual bool TruncatedVerify (const byte *digest, size_t digestLength)
 truncated version of Verify()
virtual bool VerifyTruncatedDigest (const byte *digest, size_t digestLength, const byte *input, size_t length)
 truncated version of VerifyDigest()
virtual Clonable * Clone () const
 this is not implemented by most classes yet
virtual unsigned int MandatoryBlockSize () const
 returns block size, if input must be processed in blocks, otherwise 1
virtual unsigned int GetOptimalBlockSizeUsed () const
 returns how much of the current block is used up
virtual void ProcessLastBlock (byte *outString, const byte *inString, size_t length)
 for ciphers where the last block of data is special, encrypt or decrypt the last block of data
virtual unsigned int MinLastBlockSize () const
 returns the minimum size of the last block, 0 indicating the last block is not special
void ProcessString (byte *inoutString, size_t length)
 same as ProcessData(inoutString, inoutString, length)
void ProcessString (byte *outString, const byte *inString, size_t length)
 same as ProcessData(outString, inString, length)
byte ProcessByte (byte input)
 implemented as {ProcessData(&input, &input, 1); return input;}
virtual void Seek (lword n)
 for random access ciphers, seek to an absolute position
virtual bool IsForwardTransformation () const =0
 returns whether this is an encryption object

Protected Types

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

Protected Member Functions

bool AuthenticationIsOnPlaintext () const
unsigned int AuthenticationBlockSize () const
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 AuthenticateLastFooterBlock (byte *mac, size_t macSize)
SymmetricCipher & AccessSymmetricCipher ()
const CMAC_Base & GetMAC () const
virtual CMAC_Base & AccessMAC ()=0
virtual void UncheckedSetKey (const byte *key, unsigned int length, const NameValuePairs &params)=0
void AuthenticateData (const byte *data, size_t len)
const SymmetricCipher & GetSymmetricCipher () const
virtual void AuthenticateLastConfidentialBlock ()
const Algorithm & GetAlgorithm () const
const Algorithm & GetAlgorithm () const
virtual const Algorithm & GetAlgorithm () const =0
virtual void UncheckedSpecifyDataLengths (lword headerLength, lword messageLength, lword footerLength)
void ThrowIfInvalidKeyLength (size_t length)
void ThrowIfResynchronizable ()
void ThrowIfInvalidIV (const byte *iv)
size_t ThrowIfInvalidIVLength (int size)
const byte * GetIVAndThrowIfInvalid (const NameValuePairs &params, size_t &size)
void AssertValidKeyLength (size_t length) const
void ThrowIfInvalidTruncatedSize (size_t size) const

Protected Attributes

CTR_Mode_ExternalCipher::Encryption m_ctr
State m_state
unsigned int m_bufferedDataLength
lword m_totalHeaderLength
lword m_totalMessageLength
lword m_totalFooterLength
AlignedSecByteBlock m_buffer

Detailed Description

Definition at line 11 of file eax.h.

Member Function Documentation

void SimpleKeyingInterface::SetKey ( const byte *  key,
size_t  length,
const NameValuePairs &  params = g_nullNameValuePairs 
) [virtual, inherited]

set or reset the key of this object

Parameters:
params is used to specify Rounds, BlockSize, etc.

Definition at line 60 of file cryptlib.cpp.

Referenced by SimpleKeyingInterface::SetKeyWithIV(), and SimpleKeyingInterface::SetKeyWithRounds().

void AuthenticatedSymmetricCipherBase::ProcessData ( byte *  outString,
const byte *  inString,
size_t  length 
) [virtual, inherited]

encrypt or decrypt an array of bytes of specified length

Note:
either inString == outString, or they don't overlap

Implements StreamTransformation.

Definition at line 104 of file authenc.cpp.

References AuthenticatedSymmetricCipher::AlgorithmName(), StreamTransformation::IsForwardTransformation(), AuthenticatedSymmetricCipher::MaxMessageLength(), and StreamTransformation::ProcessData().

virtual bool AuthenticatedSymmetricCipher::NeedsPrespecifiedDataLengths (  )  const [inline, virtual, inherited]

if this function returns true, SpecifyDataLengths() must be called before attempting to input data

This is the case for some schemes, such as CCM.

Reimplemented in CCM_Base.

Definition at line 646 of file cryptlib.h.

bool SimpleKeyingInterface::IsResynchronizable (  )  const [inline, inherited]

returns whether this object can be resynchronized (i.e. supports initialization vectors)

If this function returns true, and no IV is passed to SetKey() and CanUseStructuredIVs()==true, an IV of all 0's will be assumed.

Definition at line 386 of file cryptlib.h.

void SimpleKeyingInterface::GetNextIV ( RandomNumberGenerator &  rng,
byte *  IV 
) [virtual, inherited]

get a secure IV for the next message

This method should be called after you finish encrypting one message and are ready to start the next one. After calling it, you must call SetKey() or Resynchronize() before using this object again. This method is not implemented on decryption objects.

Definition at line 136 of file cryptlib.cpp.

References RandomNumberGenerator::GenerateBlock().

virtual void HashTransformation::Final ( byte *  digest  )  [inline, virtual, inherited]

compute hash for current message, then restart for a new message

Precondition:
size of digest == DigestSize().

Definition at line 545 of file cryptlib.h.

Referenced by PKCS5_PBKDF2_HMAC< T >::DeriveKey(), and HMAC_Base::TruncatedFinal().

virtual unsigned int StreamTransformation::OptimalBlockSize (  )  const [inline, virtual, inherited]

returns the input block size that is most efficient for this cipher

Note:
optimal input length is n * OptimalBlockSize() - GetOptimalBlockSizeUsed() for any n > 0

Reimplemented in ECB_OneWay.

Definition at line 481 of file cryptlib.h.

virtual bool HashTransformation::Verify ( const byte *  digest  )  [inline, virtual, inherited]

verify that digest is a valid digest for the current message, then reinitialize the object

Default implementation is to call Final() and do a bitwise comparison between its output and digest.

Definition at line 575 of file cryptlib.h.

void StreamTransformation::ProcessLastBlock ( byte *  outString,
const byte *  inString,
size_t  length 
) [virtual, inherited]

for ciphers where the last block of data is special, encrypt or decrypt the last block of data

For now the only use of this function is for CBC-CTS mode.

Reimplemented in CBC_CTS_Encryption, and CBC_CTS_Decryption.

Definition at line 194 of file cryptlib.cpp.

References Algorithm::AlgorithmName(), StreamTransformation::MandatoryBlockSize(), StreamTransformation::MinLastBlockSize(), and StreamTransformation::ProcessData().

The documentation for this class was generated from the following files:
Generated on Mon Aug 9 2010 15:57:21 for Crypto++ by  doxygen 1.7.1