digestpp::hasher< HashProvider, Mixin > Class Template Reference

Main class template implementing the public API for hashing. More...

#include <hasher.hpp>

Inheritance diagram for digestpp::hasher< HashProvider, Mixin >:

Public Member Functions
template<typename H = HashProvider, typename std::enable_if< std::is_default_constructible< H >::value >::type * = nullptr>
	hasher ()
	Default constructor.
template<typename H = HashProvider, typename std::enable_if<!detail::is_xof< H >::value >::type * = nullptr>
	hasher (size_t hashsize)
	Constructor with hash size parameter.
template<typename T , typename std::enable_if< detail::is_byte< T >::value >::type * = nullptr>
hasher &	absorb (const T *data, size_t len)
	Absorbs bytes from a C-style pointer to character buffer.
template<typename T , size_t N, typename std::enable_if< detail::is_byte< T >::value >::type * = nullptr>
hasher &	absorb (const std::array< T, N > &arr)
	Absorbs bytes from a C++ style array to character buffer.
template<typename T , typename std::enable_if< detail::is_byte< T >::value &&!std::is_same< T, std::string::value_type >::value >::type * = nullptr>
hasher &	absorb (const std::basic_string< T > &str)
	Absorbs bytes from std::basic_string.
hasher &	absorb (const std::string &str)
	Absorbs bytes from std::string.
template<typename T , typename std::enable_if< detail::is_byte< T >::value >::type * = nullptr>
hasher &	absorb (std::basic_istream< T > &istr)
	Absorbs bytes from std::istream.
template<typename IT >
hasher &	absorb (IT begin, IT end)
	Absorbs bytes from an iterator sequence.
template<typename T , typename H = HashProvider, typename std::enable_if< detail::is_byte< T >::value &&detail::is_xof< H >::value >::type * = nullptr>
void	squeeze (T *buf, size_t len)
	Squeeze bytes into user-provided preallocated buffer.
template<typename T , size_t N, typename H = HashProvider, typename std::enable_if< detail::is_byte< T >::value &&detail::is_xof< H >::value >::type * = nullptr>
void	squeeze (T(&arr)[N])
	Squeeze bytes into user-provided preallocated buffer.
template<typename T , size_t N, typename H = HashProvider, typename std::enable_if< detail::is_byte< T >::value &&detail::is_xof< H >::value >::type * = nullptr>
void	squeeze (std::array< T, N > &arr)
	Squeeze bytes into user-provided preallocated buffer.
template<typename OI , typename H = HashProvider, typename std::enable_if< detail::is_xof< H >::value >::type * = nullptr>
void	squeeze (size_t len, OI it)
	Squeeze bytes into an output iterator.
template<typename H = HashProvider, typename std::enable_if< detail::is_xof< H >::value >::type * = nullptr>
std::string	hexsqueeze (size_t len)
	Squeeze bytes and return them as a hex string.
template<typename T , typename H = HashProvider, typename std::enable_if< detail::is_byte< T >::value &&!detail::is_xof< H >::value >::type * = nullptr>
void	digest (T *buf, size_t len) const
	Output binary digest into user-provided preallocated buffer.
template<typename OI , typename H = HashProvider, typename std::enable_if<!detail::is_xof< H >::value >::type * = nullptr>
void	digest (OI it) const
	Write binary digest into an output iterator.
template<typename H = HashProvider, typename std::enable_if<!detail::is_xof< H >::value >::type * = nullptr>
std::string	hexdigest () const
	Return hex digest of absorbed data.
void	reset (bool resetParameters=false)
	Reset the hasher state to start new digest computation.

Detailed Description

template<class HashProvider, template< class > class Mixin = mixin::null_mixin>
class digestpp::hasher< HashProvider, Mixin >

Main class template implementing the public API for hashing.

Individual hash functions are defined by typedefs. See digestpp namespace description for description of supported hash functions with usage examples.

Parameters

HashProvider	A class implementing the algorithm via traditional init/update/final interface.
Mixin	A class template which can be used to inject additional functions to the public API of the hasher.

See also

digestpp

Constructor & Destructor Documentation

hasher() [1/2]

template<class HashProvider , template< class > class Mixin = mixin::null_mixin>

template<typename H = HashProvider, typename std::enable_if< std::is_default_constructible< H >::value >::type * = nullptr>

digestpp::hasher< HashProvider, Mixin >::hasher ( )

inline

Default constructor.

Available if:

• HashProvider is a hash function with fixed output size, OR
• HashProvider is a hash function with sensible default output size, OR
• HashProvider is an extendable output function (XOF)

hasher() [2/2]

template<class HashProvider , template< class > class Mixin = mixin::null_mixin>

template<typename H = HashProvider, typename std::enable_if<!detail::is_xof< H >::value >::type * = nullptr>

digestpp::hasher< HashProvider, Mixin >::hasher ( size_t hashsize )

inline

Constructor with hash size parameter.

Supported output sizes for each algorithm are listed in the description of corresponding typedef.

Available if:

HashProvider supports multiple output sizes, AND

• HashProvider is not an extendable output function (XOF)

Parameters

[in]

hashsize

Desired output digest size (in bits).

Exceptions

std::runtime_error

if the requested output size is not supported by the algorithm.

Member Function Documentation

absorb() [1/6]

template<class HashProvider , template< class > class Mixin = mixin::null_mixin>

template<typename T , size_t N, typename std::enable_if< detail::is_byte< T >::value >::type * = nullptr>

hasher & digestpp::hasher< HashProvider, Mixin >::absorb ( const std::array< T, N > & arr )

inline

Absorbs bytes from a C++ style array to character buffer.

Parameters

[in]

arr

Array to data to absorb

Returns

Reference to *this

Example:

 // Calculate SHA-512/256 digest of a C array and output it in hex format
std::array<unsigned char, 32> c;
std::iota(c.data(), c.size(), 0);
cout << digestpp::sha512(256).absorb(c).hexdigest() << std::endl;

absorb() [2/6]

template<class HashProvider , template< class > class Mixin = mixin::null_mixin>

template<typename T , typename std::enable_if< detail::is_byte< T >::value &&!std::is_same< T, std::string::value_type >::value >::type * = nullptr>

hasher & digestpp::hasher< HashProvider, Mixin >::absorb ( const std::basic_string< T > & str )

inline

Absorbs bytes from std::basic_string.

Parameters

[in]

str

String to absorb

Returns

Reference to *this

absorb() [3/6]

template<class HashProvider , template< class > class Mixin = mixin::null_mixin>

hasher & digestpp::hasher< HashProvider, Mixin >::absorb ( const std::string & str )

inline

Absorbs bytes from std::string.

Parameters

[in]

str

String to absorb

Returns

Reference to *this

Example:

 // Calculate BLAKE2b-256 digest from an std::string and output it in hex format
std::string str = "The quick brown fox jumps over the lazy dog";
std::cout << digestpp::blake2b(256).absorb(str).hexdigest() << std::endl;

absorb() [4/6]

template<class HashProvider , template< class > class Mixin = mixin::null_mixin>

template<typename T , typename std::enable_if< detail::is_byte< T >::value >::type * = nullptr>

hasher & digestpp::hasher< HashProvider, Mixin >::absorb ( const T * data, size_t len )

inline

Absorbs bytes from a C-style pointer to character buffer.

Parameters

[in]	data	Pointer to data to absorb
[in]	len	Size of data to absorb (in bytes)

Returns

Reference to *this

Example:

 // Calculate SHA-512/256 digest of a C array and output it in hex format
unsigned char c[32];
std::iota(c, c + sizeof(c), 0);
cout << digestpp::sha512(256).absorb(c, sizeof(c)).hexdigest() << std::endl;

absorb() [5/6]

template<class HashProvider , template< class > class Mixin = mixin::null_mixin>

template<typename IT >

hasher & digestpp::hasher< HashProvider, Mixin >::absorb ( IT begin, IT end )

inline

Absorbs bytes from an iterator sequence.

Parameters

[in]	begin	Begin iterator
[in]	end	End iterator

Returns

Reference to *this

Example:

 // Calculate SHA-512 digest of a vector and output it in hex format
std::vector<unsigned char> v(100);
std::iota(v.begin(), v.end(), 0);
std::cout << digestpp::sha512().absorb(v.begin(), v.end()).hexdigest() << std::endl;

absorb() [6/6]

template<class HashProvider , template< class > class Mixin = mixin::null_mixin>

template<typename T , typename std::enable_if< detail::is_byte< T >::value >::type * = nullptr>

hasher & digestpp::hasher< HashProvider, Mixin >::absorb ( std::basic_istream< T > & istr )

inline

Absorbs bytes from std::istream.

Parameters

[in]

istr

Stream to absorb

Returns

Reference to *this

Example:

 // Calculate SHA-256 digest of a file and output it in hex format
std::ifstream file("filename", std::ios_base::in|std::ios_base::binary);
std::cout << digestpp::sha256().absorb(file).hexdigest() << std::endl;

digest() [1/2]

template<class HashProvider , template< class > class Mixin = mixin::null_mixin>

template<typename OI , typename H = HashProvider, typename std::enable_if<!detail::is_xof< H >::value >::type * = nullptr>

void digestpp::hasher< HashProvider, Mixin >::digest ( OI it ) const

inline

Write binary digest into an output iterator.

This function does not change the state of the hasher and can be called multiple times, producing the same result. To reset the state and start new digest calculation, use reset function.

Available if:

HashProvider is a hash function (not XOF)

Parameters

[out]

it

Output iterator to a byte container.

Example:

 // Output binary SHA3-256 digest to a vector
vector<unsigned char> v;
digestpp::sha3(256).absorb("The quick brown fox jumps over the lazy dog").digest(back_inserter(v));

digest() [2/2]

template<class HashProvider , template< class > class Mixin = mixin::null_mixin>

template<typename T , typename H = HashProvider, typename std::enable_if< detail::is_byte< T >::value &&!detail::is_xof< H >::value >::type * = nullptr>

void digestpp::hasher< HashProvider, Mixin >::digest ( T * buf, size_t len ) const

inline

Output binary digest into user-provided preallocated buffer.

This function does not change the state of the hasher and can be called multiple times, producing the same result. To reset the state and start new digest calculation, use reset function.

Available if:

HashProvider is a hash function (not XOF)

Parameters

[out]	buf	Buffer to squeeze data to; must be of byte type (char, unsigned char or signed char)
[in]	len	Size of the buffer

Exceptions

std::runtime_error

if the buffer size is not enough to fit the calculated digest (fixed by the algorithm or specified in the hasher constructor).

Example:

 // Output binary digest to a raw C array
unsigned char buf[32];
digestpp::sha3(256).absorb("The quick brown fox jumps over the lazy dog").digest(buf, sizeof(buf));

hexdigest()

template<class HashProvider , template< class > class Mixin = mixin::null_mixin>

template<typename H = HashProvider, typename std::enable_if<!detail::is_xof< H >::value >::type * = nullptr>

std::string digestpp::hasher< HashProvider, Mixin >::hexdigest ( ) const

inline

Return hex digest of absorbed data.

This function does not change the state of the hasher and can be called multiple times, producing the same result. To reset the state and start new digest calculation, use reset function.

Available if:

HashProvider is a hash function (not XOF)

Returns

Calculated digest as a hexademical string

Example:

 // Calculate BLAKE2b digest from a double quoted string and output it in hex format
std::cout << digestpp::blake2b().absorb("The quick brown fox jumps over the lazy dog").hexdigest() << std::endl;

hexsqueeze()

template<class HashProvider , template< class > class Mixin = mixin::null_mixin>

template<typename H = HashProvider, typename std::enable_if< detail::is_xof< H >::value >::type * = nullptr>

std::string digestpp::hasher< HashProvider, Mixin >::hexsqueeze ( size_t len )

inline

Squeeze bytes and return them as a hex string.

After each invocation of this function the internal state of the hasher changes so that the next call will generate different (additional) output bytes. To reset the state and start new digest calculation, use reset function.

Available if:

HashProvider is an extendable output function (XOF)

Parameters

[in]

len

Size of data to squeeze (in bytes)

Returns

Calculated digest as a hexademical string

Example:

 // Generate 64-byte digest using customizable cSHAKE-256 algorithm and print it in hex format
digestpp::cshake256 xof;
xof.set_customization("My Customization");
std::cout << xof.absorb("The quick brown fox jumps over the lazy dog").hexsqueeze(64) << std::endl;

reset()

template<class HashProvider , template< class > class Mixin = mixin::null_mixin>

void digestpp::hasher< HashProvider, Mixin >::reset ( bool resetParameters = false )

inline

Reset the hasher state to start new digest computation.

Parameters

[in]

resetParameters

if true, also clear optional parameters (personalization, salt, etc)

squeeze() [1/4]

template<class HashProvider , template< class > class Mixin = mixin::null_mixin>

template<typename OI , typename H = HashProvider, typename std::enable_if< detail::is_xof< H >::value >::type * = nullptr>

void digestpp::hasher< HashProvider, Mixin >::squeeze ( size_t len, OI it )

inline

Squeeze bytes into an output iterator.

After each invocation of this function the internal state of the hasher changes so that the next call will generate different (additional) output bytes. To reset the state and start new digest calculation, use reset function.

Available if:

HashProvider is an extendable output function (XOF)

Parameters

[in]	len	Size of data to squeeze (in bytes)
[out]	it	output iterator to a byte container

Example:

 // Generate long output using SHAKE-256 extendable output function using multiple calls to squeeze()
std::vector<unsigned char> v;
digestpp::shake256 xof;
xof.absorb("The quick brown fox jumps over the lazy dog");
xof.squeeze(1000, back_inserter(v));
xof.squeeze(1000, back_inserter(v));
xof.squeeze(1000, back_inserter(v));
std::cout << "Squeezed " << v.size() << " bytes." << std::endl;

squeeze() [2/4]

template<class HashProvider , template< class > class Mixin = mixin::null_mixin>

template<typename T , size_t N, typename H = HashProvider, typename std::enable_if< detail::is_byte< T >::value &&detail::is_xof< H >::value >::type * = nullptr>

void digestpp::hasher< HashProvider, Mixin >::squeeze ( std::array< T, N > & arr )

inline

Squeeze bytes into user-provided preallocated buffer.

After each invocation of this function the internal state of the hasher changes so that the next call will generate different (additional) output bytes. To reset the state and start new digest calculation, use reset function.

Available if:

HashProvider is an extendable output function (XOF)

Parameters

[out]

arr

Buffer to squeeze data to; must be of byte type (char, unsigned char or signed char)

squeeze() [3/4]

template<class HashProvider , template< class > class Mixin = mixin::null_mixin>

template<typename T , typename H = HashProvider, typename std::enable_if< detail::is_byte< T >::value &&detail::is_xof< H >::value >::type * = nullptr>

void digestpp::hasher< HashProvider, Mixin >::squeeze ( T * buf, size_t len )

inline

Squeeze bytes into user-provided preallocated buffer.

After each invocation of this function the internal state of the hasher changes so that the next call will generate different (additional) output bytes. To reset the state and start new digest calculation, use reset function.

Available if:

HashProvider is an extendable output function (XOF)

Parameters

[out]	buf	Buffer to squeeze data to; must be of byte type (char, unsigned char or signed char)
[in]	len	Size of data to squeeze (in bytes)

squeeze() [4/4]

template<class HashProvider , template< class > class Mixin = mixin::null_mixin>

template<typename T , size_t N, typename H = HashProvider, typename std::enable_if< detail::is_byte< T >::value &&detail::is_xof< H >::value >::type * = nullptr>

void digestpp::hasher< HashProvider, Mixin >::squeeze ( T(&) arr[N] )

inline

Squeeze bytes into user-provided preallocated buffer.

After each invocation of this function the internal state of the hasher changes so that the next call will generate different (additional) output bytes. To reset the state and start new digest calculation, use reset function.

Available if:

HashProvider is an extendable output function (XOF)

Parameters

[out]

arr

Buffer to squeeze data to; must be of byte type (char, unsigned char or signed char)

---

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

• hasher.hpp