plssvm::detail::sha256 Class Reference

A hashing struct used for sha256 hashing. More...

#include <sha256.hpp>

Public Member Functions
std::string	operator() (std::string input) const
	Calculate the sha256 hash for the input string. More...

Static Private Member Functions
template<typename T , std::enable_if_t< std::is_unsigned_v< T >, bool > = true>
static void	unpack (const T x, unsigned char *str)
	Unpack the bits of x into the str. More...
static void	pack32 (const unsigned char *str, std::uint32_t &x)
	Pack four byte of the str into the 32-bit unsigned integer x. More...
static std::uint32_t	rotr32 (std::uint32_t value, unsigned int count)
	Rotate the bits in value @ count times to the right. More...

Static Private Attributes
static constexpr std::uint32_t	DIGEST_SIZE = 256 / 8
	Number of bytes in the resulting digest.
static constexpr std::uint32_t	CHUNK_SIZE = 512 / 8
	NUmber of bytes processed in one round (chunk).
static constexpr std::array< std::uint32_t, 64 >	k_
	Array of the sha256 round constants. More...

Detailed Description

A hashing struct used for sha256 hashing.

Based on: https://en.wikipedia.org/wiki/SHA-2#Pseudocode

Member Function Documentation

operator()()

std::string plssvm::detail::sha256::operator()

(

std::string

input

)

const

Calculate the sha256 hash for the input string.

Parameters

[in]

input

the string to hash

Returns

the sha256 hash of input ([[nodiscard]])

unpack()

template<typename T , std::enable_if_t< std::is_unsigned_v< T >, bool > = true>

static void plssvm::detail::sha256::unpack ( const T  x, unsigned char *  str  )

inlinestaticprivate

Unpack the bits of x into the str.

Template Parameters

T	the unsigned type and, therefore, number of bits, to unpack

Parameters

[in]	x	the integer representing the bits to unpack
[out]	str	the string to unpack the bits to

pack32()

static void plssvm::detail::sha256::pack32 ( const unsigned char *  str, std::uint32_t &  x  )

staticprivate

Pack four byte of the str into the 32-bit unsigned integer x.

Parameters

[in]	str	the string to pack
[out]	x	the 32-bit unsigned integer to pack the bytes to

rotr32()

static std::uint32_t plssvm::detail::sha256::rotr32 ( std::uint32_t  value, unsigned int  count  )

staticprivate

Rotate the bits in value @ count times to the right.

Based on: https://en.wikipedia.org/wiki/Circular_shift

Parameters

[in]	value	the 32-bit integer to rotate
[in]	count	the number of bits to rotate

Returns

the rotated 32-bit integer ([[nodiscard]])

Member Data Documentation

k_

constexpr std::array<std::uint32_t, 64> plssvm::detail::sha256::k_

staticconstexprprivate

Initial value:

{
        
        0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
        0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
        0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
        0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
        0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
        0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
        0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
        0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
        
    }

Array of the sha256 round constants.

First 32 bits of the fractional parts of the cube roots of the first 64 primes 2..311.

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

• include/plssvm/detail/sha256.hpp