Crypto++  5.6.4
Free C++ class library of cryptographic schemes
Public Types | Public Member Functions | List of all members
SimpleKeyingInterface Class Referenceabstract

Interface for algorithms that take byte strings as keys. More...

+ Inheritance diagram for SimpleKeyingInterface:

Public Types

enum  IV_Requirement {
  UNIQUE_IV = 0, RANDOM_IV, UNPREDICTABLE_RANDOM_IV, INTERNALLY_GENERATED_IV,
  NOT_RESYNCHRONIZABLE
}
 Secure IVs requirements as enumerated values. More...
 

Public Member Functions

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
 
virtual bool IsValidKeyLength (size_t keylength) const
 Returns whether keylength is a valid key length. More...
 
virtual void SetKey (const byte *key, size_t length, const NameValuePairs &params=g_nullNameValuePairs)
 Sets or reset the key of this object. More...
 
void SetKeyWithRounds (const byte *key, size_t length, int rounds)
 Sets or reset the key of this object. More...
 
void SetKeyWithIV (const byte *key, size_t length, const byte *iv, size_t ivLength)
 Sets or reset the key of this object. More...
 
void SetKeyWithIV (const byte *key, size_t length, const byte *iv)
 Sets or reset the key of this object. More...
 
virtual IV_Requirement IVRequirement () const =0
 Minimal requirement for secure IVs. More...
 
bool IsResynchronizable () const
 Determines if the object can be resynchronized. More...
 
bool CanUseRandomIVs () const
 Determines if the object can use random IVs. More...
 
bool CanUsePredictableIVs () const
 Determines if the object can use random but possibly predictable IVs. More...
 
bool CanUseStructuredIVs () const
 Determines if the object can use structured IVs. More...
 
virtual unsigned int IVSize () const
 Returns length of the IV accepted by this object. More...
 
unsigned int DefaultIVLength () const
 Provides the default size of an IV. More...
 
virtual unsigned int MinIVLength () const
 Provides the minimum size of an IV. More...
 
virtual unsigned int MaxIVLength () const
 Provides the maximum size of an IV. More...
 
virtual void Resynchronize (const byte *iv, int ivLength=-1)
 Resynchronize with an IV. More...
 
virtual void GetNextIV (RandomNumberGenerator &rng, byte *iv)
 Retrieves a secure IV for the next message. More...
 

Detailed Description

Interface for algorithms that take byte strings as keys.

See also
FixedKeyLength(), VariableKeyLength(), SameKeyLengthAs(), SimpleKeyingInterfaceImpl()

Definition at line 529 of file cryptlib.h.

Member Enumeration Documentation

Secure IVs requirements as enumerated values.

Provides secure IV requirements as a monotomically increasing enumerated values. Requirements can be compared using less than (<) and greater than (>). For example, UNIQUE_IV < RANDOM_IV and UNPREDICTABLE_RANDOM_IV > RANDOM_IV.

See also
IsResynchronizable(), CanUseRandomIVs(), CanUsePredictableIVs(), CanUseStructuredIVs()
Enumerator
UNIQUE_IV 

The IV must be unique.

RANDOM_IV 

The IV must be random and possibly predictable.

UNPREDICTABLE_RANDOM_IV 

The IV must be random and unpredictable.

INTERNALLY_GENERATED_IV 

The IV is set by the object.

NOT_RESYNCHRONIZABLE 

The object does not use an IV.

Definition at line 595 of file cryptlib.h.

Member Function Documentation

virtual size_t SimpleKeyingInterface::GetValidKeyLength ( size_t  n) const
pure virtual
virtual bool SimpleKeyingInterface::IsValidKeyLength ( size_t  keylength) const
inlinevirtual

Returns whether keylength is a valid key length.

Parameters
keylengththe requested keylength
Returns
true if keylength is valid, false otherwise

Internally the function calls GetValidKeyLength()

Reimplemented in CipherModeBase, GCM_Base, CCM_Base, and EAX_Base.

Definition at line 550 of file cryptlib.h.

void SimpleKeyingInterface::SetKey ( const byte *  key,
size_t  length,
const NameValuePairs params = g_nullNameValuePairs 
)
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 that cannot be passed directly through the constructor

Reimplemented in ECB_OneWay, and AuthenticatedSymmetricCipherBase.

Definition at line 97 of file cryptlib.cpp.

void SimpleKeyingInterface::SetKeyWithRounds ( const byte *  key,
size_t  length,
int  rounds 
)

Sets or reset the key of this object.

Parameters
keythe key to use when keying the object
lengththe size of the key, in bytes
roundsthe number of rounds to apply the transformation function, if applicable

SetKeyWithRounds() calls SetKey() with a NameValuePairs object that only specifies rounds. rounds is an integer parameter, and -1 means use the default number of rounds.

Definition at line 103 of file cryptlib.cpp.

void SimpleKeyingInterface::SetKeyWithIV ( const byte *  key,
size_t  length,
const byte *  iv,
size_t  ivLength 
)

Sets or reset the key of this object.

Parameters
keythe key to use when keying the object
lengththe size of the key, in bytes
ivthe intiialization vector to use when keying the object
ivLengththe size of the iv, in bytes

SetKeyWithIV() calls SetKey() with a NameValuePairs that only specifies IV. The IV is a byte buffer with size ivLength. ivLength is an integer parameter, and -1 means use IVSize().

Definition at line 108 of file cryptlib.cpp.

void SimpleKeyingInterface::SetKeyWithIV ( const byte *  key,
size_t  length,
const byte *  iv 
)
inline

Sets or reset the key of this object.

Parameters
keythe key to use when keying the object
lengththe size of the key, in bytes
ivthe intiialization vector to use when keying the object

SetKeyWithIV() calls SetKey() with a NameValuePairs() object that only specifies iv. iv is a byte buffer, and it must have a size IVSize().

Definition at line 587 of file cryptlib.h.

virtual IV_Requirement SimpleKeyingInterface::IVRequirement ( ) const
pure virtual
bool SimpleKeyingInterface::IsResynchronizable ( ) const
inline

Determines if the object can be resynchronized.

Returns
true if the object can be resynchronized (i.e. supports initialization vectors), false otherwise
Note
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 616 of file cryptlib.h.

bool SimpleKeyingInterface::CanUseRandomIVs ( ) const
inline

Determines if the object can use random IVs.

Returns
true if the object can use random IVs (in addition to ones returned by GetNextIV), false otherwise

Definition at line 620 of file cryptlib.h.

bool SimpleKeyingInterface::CanUsePredictableIVs ( ) const
inline

Determines if the object can use random but possibly predictable IVs.

Returns
true if the object can use random but possibly predictable IVs (in addition to ones returned by GetNextIV), false otherwise

Definition at line 625 of file cryptlib.h.

bool SimpleKeyingInterface::CanUseStructuredIVs ( ) const
inline

Determines if the object can use structured IVs.

Returns
true if the object can use structured IVs, false otherwise

CanUseStructuredIVs() indicates whether the object can use structured IVs; for example a counter (in addition to ones returned by GetNextIV).

Definition at line 631 of file cryptlib.h.

virtual unsigned int SimpleKeyingInterface::IVSize ( ) const
inlinevirtual
unsigned int SimpleKeyingInterface::DefaultIVLength ( ) const
inline

Provides the default size of an IV.

Returns
default length of IVs accepted by this object, in bytes

Definition at line 642 of file cryptlib.h.

virtual unsigned int SimpleKeyingInterface::MinIVLength ( ) const
inlinevirtual

Provides the minimum size of an IV.

Returns
minimal length of IVs accepted by this object, in bytes
Exceptions
NotImplemented()if the object does not support resynchronization

Reimplemented in GCM_Base, CCM_Base, EAX_Base, and VMAC_Base.

Definition at line 647 of file cryptlib.h.

virtual unsigned int SimpleKeyingInterface::MaxIVLength ( ) const
inlinevirtual

Provides the maximum size of an IV.

Returns
maximal length of IVs accepted by this object, in bytes
Exceptions
NotImplemented()if the object does not support resynchronization

Reimplemented in GCM_Base, CCM_Base, and EAX_Base.

Definition at line 652 of file cryptlib.h.

virtual void SimpleKeyingInterface::Resynchronize ( const byte *  iv,
int  ivLength = -1 
)
inlinevirtual

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 in AdditiveCipherTemplate< AbstractPolicyHolder< AdditiveCipherAbstractPolicy, CTR_ModePolicy > >, BlockOrientedCipherModeBase, AuthenticatedSymmetricCipherBase, and VMAC_Base.

Definition at line 659 of file cryptlib.h.

void SimpleKeyingInterface::GetNextIV ( RandomNumberGenerator rng,
byte *  iv 
)
virtual

Retrieves a secure IV for the next message.

Parameters
rnga RandomNumberGenerator to produce keying material
iva block of bytes to receive the IV

The IV must be at least IVSize() in length.

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.

Internally, the base class implementation calls RandomNumberGenerator's GenerateBlock()

Note
This method is not implemented on decryption objects.

Reimplemented in VMAC_Base.

Definition at line 173 of file cryptlib.cpp.


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