ChaCha20 Class Reference

Unrestricted ChaCha20 cipher. More...

#include <chacha20.h>

Collaboration diagram for ChaCha20:

Public Types
using	Nonce96 = ChaCha20Aligned::Nonce96
	96-bit nonce type.

Public Member Functions
	ChaCha20 () noexcept=delete
	For safety, disallow initialization without key.
	ChaCha20 (std::span< const std::byte > key) noexcept
	Initialize a cipher with specified 32-byte key.
	~ChaCha20 ()
	Destructor to clean up private memory.
void	SetKey (std::span< const std::byte > key) noexcept
	Set 32-byte key, and seek to nonce 0 and block position 0.
void	Seek (Nonce96 nonce, uint32_t block_counter) noexcept
	Set the 96-bit nonce and 32-bit block counter.
void	Crypt (std::span< const std::byte > in_bytes, std::span< std::byte > out_bytes) noexcept
	en/deciphers the message <in_bytes> and write the result into <out_bytes>
void	Keystream (std::span< std::byte > out) noexcept
	outputs the keystream to out.

Static Public Attributes
static constexpr unsigned	KEYLEN = ChaCha20Aligned::KEYLEN
	Expected key length in constructor and SetKey.

Private Attributes
ChaCha20Aligned	m_aligned
std::array< std::byte, ChaCha20Aligned::BLOCKLEN >	m_buffer
unsigned	m_bufleft {0}

Detailed Description

Unrestricted ChaCha20 cipher.

Definition at line 75 of file chacha20.h.

Member Typedef Documentation

Nonce96

using ChaCha20::Nonce96 = ChaCha20Aligned::Nonce96

96-bit nonce type.

Definition at line 99 of file chacha20.h.

Constructor & Destructor Documentation

ChaCha20() [1/2]

ChaCha20::ChaCha20 ( )

deletenoexcept

For safety, disallow initialization without key.

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ChaCha20() [2/2]

ChaCha20::ChaCha20 ( std::span< const std::byte > key )

inlinenoexcept

Initialize a cipher with specified 32-byte key.

Definition at line 90 of file chacha20.h.

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~ChaCha20()

ChaCha20::~ChaCha20

(

)

Destructor to clean up private memory.

Definition at line 331 of file chacha20.cpp.

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Member Function Documentation

Crypt()

void ChaCha20::Crypt ( std::span< const std::byte > in_bytes, std::span< std::byte > out_bytes )

noexcept

en/deciphers the message <in_bytes> and write the result into <out_bytes>

The size of in_bytes and out_bytes must be equal.

Definition at line 302 of file chacha20.cpp.

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Keystream()

void ChaCha20::Keystream ( std::span< std::byte > out )

noexcept

outputs the keystream to out.

Definition at line 281 of file chacha20.cpp.

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Seek()

void ChaCha20::Seek ( Nonce96 nonce, uint32_t block_counter )

inlinenoexcept

Set the 96-bit nonce and 32-bit block counter.

See ChaCha20Aligned::Seek.

Definition at line 102 of file chacha20.h.

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SetKey()

void ChaCha20::SetKey ( std::span< const std::byte > key )

noexcept

Set 32-byte key, and seek to nonce 0 and block position 0.

Definition at line 336 of file chacha20.cpp.

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Member Data Documentation

KEYLEN

unsigned ChaCha20::KEYLEN = ChaCha20Aligned::KEYLEN

staticconstexpr

Expected key length in constructor and SetKey.

Definition at line 84 of file chacha20.h.

m_aligned

ChaCha20Aligned ChaCha20::m_aligned

private

Definition at line 78 of file chacha20.h.

m_buffer

std::array<std::byte, ChaCha20Aligned::BLOCKLEN> ChaCha20::m_buffer

private

Definition at line 79 of file chacha20.h.

m_bufleft

unsigned ChaCha20::m_bufleft {0}

private

Definition at line 80 of file chacha20.h.

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

• src/crypto/chacha20.h
• src/crypto/chacha20.cpp