Poly1305-TLS message authentication code. More...

#include <poly1305.h>

Inheritance diagram for Poly1305TLS:

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...

Public Member Functions inherited from MessageAuthenticationCodeFinal< Poly1305TLS_Base >
	MessageAuthenticationCodeFinal ()
	Construct a default MessageAuthenticationCodeFinal. More...

	MessageAuthenticationCodeFinal (const byte *key)
	Construct a BlockCipherFinal. More...

	MessageAuthenticationCodeFinal (const byte *key, size_t length)
	Construct a BlockCipherFinal. More...

Public Member Functions inherited from ClonableImpl< MessageAuthenticationCodeFinal< Poly1305TLS_Base >, MessageAuthenticationCodeImpl< Poly1305TLS_Base > >
Clonable *	Clone () const
	Create a copy of this object. More...

Public Member Functions inherited from AlgorithmImpl< SimpleKeyingInterfaceImpl< Poly1305TLS_Base, Poly1305TLS_Base >, Poly1305TLS_Base >
std::string	AlgorithmName () const
	The algorithm name. More...

Public Member Functions inherited from SimpleKeyingInterfaceImpl< Poly1305TLS_Base, Poly1305TLS_Base >
size_t	MinKeyLength () const
	The minimum key length used by the algorithm. More...

size_t	MaxKeyLength () const
	The maximum key length used by the algorithm. More...

size_t	DefaultKeyLength () const
	The default key length used by the algorithm. More...

size_t	GetValidKeyLength (size_t keylength) const
	Provides a valid key length for the algorithm. More...

SimpleKeyingInterface::IV_Requirement	IVRequirement () const
	The default IV requirements for the algorithm. More...

unsigned int	IVSize () const
	The initialization vector length for the algorithm. More...

Public Member Functions inherited from Poly1305TLS_Base
void	UncheckedSetKey (const byte *key, unsigned int length, const NameValuePairs &params)
	Sets the key for this object without performing parameter validation. More...

void	Update (const byte *input, size_t length)
	Updates a hash with additional input. More...

void	TruncatedFinal (byte *mac, size_t size)
	Computes the hash of the current message. More...

void	Restart ()
	Restart the hash. More...

unsigned int	BlockSize () const
	Provides the block size of the compression function. More...

unsigned int	DigestSize () const
	Provides the digest size of the hash. More...

Public Member Functions inherited from SimpleKeyingInterface
virtual size_t	MinKeyLength () const =0
	Returns smallest valid key length. More...

virtual size_t	MaxKeyLength () const =0
	Returns largest valid key length. More...

virtual size_t	DefaultKeyLength () const =0
	Returns default key length. More...

virtual size_t	GetValidKeyLength (size_t keylength) const =0
	Returns a valid key length for the algorithm. More...

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...

Public Member Functions inherited from HashTransformation
HashTransformation &	Ref ()
	Provides a reference to this object. More...

virtual void	Update (const byte *input, size_t length)=0
	Updates a hash with additional input. More...

virtual byte *	CreateUpdateSpace (size_t &size)
	Request space which can be written into by the caller. More...

virtual void	Final (byte *digest)
	Computes the hash of the current message. More...

virtual void	Restart ()
	Restart the hash. More...

virtual unsigned int	DigestSize () const =0
	Provides the digest size of the hash. More...

unsigned int	TagSize () const
	Provides the tag size of the hash. More...

virtual unsigned int	BlockSize () const
	Provides the block size of the compression function. More...

virtual unsigned int	OptimalBlockSize () const
	Provides the input block size most efficient for this hash. More...

virtual unsigned int	OptimalDataAlignment () const
	Provides input and output data alignment for optimal performance. More...

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. More...

virtual bool	Verify (const byte *digest)
	Verifies the hash of the current message. More...

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. More...

virtual void	TruncatedFinal (byte *digest, size_t digestSize)=0
	Computes the hash of the current message. More...

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. More...

virtual bool	TruncatedVerify (const byte *digest, size_t digestLength)
	Verifies the hash of the current message. More...

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. More...

Public Member Functions inherited from Algorithm
	Algorithm (bool checkSelfTestStatus=true)
	Interface for all crypto algorithms. More...

virtual std::string	AlgorithmName () const
	Provides the name of this algorithm. More...

virtual std::string	AlgorithmProvider () const
	Retrieve the provider of this algorithm. More...

virtual Clonable *	Clone () const
	Copies this object. More...

Static Public Member Functions inherited from AlgorithmImpl< SimpleKeyingInterfaceImpl< Poly1305TLS_Base, Poly1305TLS_Base >, Poly1305TLS_Base >
static std::string	StaticAlgorithmName ()
	The algorithm name. More...

Static Public Member Functions inherited from Poly1305TLS_Base
static std::string	StaticAlgorithmName ()

Static Public Member Functions inherited from FixedKeyLength< 32 >
static size_t	StaticGetValidKeyLength (size_t keylength)
	The default key length for the algorithm provided by a static function. More...

Static Public Attributes inherited from Poly1305TLS_Base
static const int	DIGESTSIZE =16

static const int	BLOCKSIZE =16

Static Public Attributes inherited from FixedKeyLength< 32 >
static const int	KEYLENGTH
	The default key length used by the algorithm provided as a constant. More...

static const int	MIN_KEYLENGTH
	The minimum key length used by the algorithm provided as a constant. More...

static const int	MAX_KEYLENGTH
	The maximum key length used by the algorithm provided as a constant. More...

static const int	DEFAULT_KEYLENGTH
	The default key length used by the algorithm provided as a constant. More...

static const int	IV_REQUIREMENT
	The default IV requirements for the algorithm provided as a constant. More...

static const int	IV_LENGTH
	The default IV length used by the algorithm provided as a constant. More...

Detailed Description

Poly1305-TLS message authentication code.

This is the IETF's variant of Bernstein's Poly1305 from RFC 8439. IETF Poly1305 is called Poly1305TLS in the Crypto++ library. It is _slightly_ different from the Bernstein implementation. Poly1305-TLS can be used for cipher suites TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256, TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256, and TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256.

The key is 32 bytes and a concatenation key = {r,s}, where r is additional key that gets clamped and s is the nonce. The key is clamped internally so there is no need to perform the operation before setting the key.

Each message must have a unique security context, which means the key must be changed after each message. It can be accomplished in one of two ways. First, you can create a new Poly1305 object with a new key each time its needed.

  SecByteBlock key(32);
  prng.GenerateBlock(key, key.size());

  Poly1305TLS poly1305(key, key.size());
  poly1305.Update(...);
  poly1305.Final(...);

Second, you can create a Poly1305 object, and use a new key for each message. The keys can be generated directly using a RandomNumberGenerator() derived class.

  SecByteBlock key(32);
  prng.GenerateBlock(key, key.size());

  // First message
  Poly1305TLS poly1305(key, key.size());
  poly1305.Update(...);
  poly1305.Final(...);

  // Second message
  prng.GenerateBlock(key, key.size());
  poly1305.SetKey(key, key.size());
  poly1305.Update(...);
  poly1305.Final(...);
  ...

Warning: Each message must have a unique security context. The Poly1305-TLS class does not enforce a fresh key or nonce for each message.

Since: Crypto++ 8.1

See also: MessageAuthenticationCode(), RFC 8439, ChaCha20 and Poly1305 for IETF Protocols

Definition at line 237 of file poly1305.h.

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

poly1305.h

Additional Inherited Members

Detailed Description