ChaCha20 Class Reference

Unrestricted ChaCha20 cipher. More...

#include <chacha20.h>

Collaboration diagram for ChaCha20:

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

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

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

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 89 of file chacha20.h.

Member Typedef Documentation

Nonce96

using ChaCha20::Nonce96 = ChaCha20Aligned::Nonce96

96-bit nonce type.

Definition at line 112 of file chacha20.h.

Constructor & Destructor Documentation

ChaCha20() [1/2]

ChaCha20::ChaCha20 ( )

deletenoexcept

For safety, disallow initialization without key.

ChaCha20() [2/2]

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

inlinenoexcept

Initialize a cipher with specified KEYLEN-byte key.

Definition at line 103 of file chacha20.h.

~ChaCha20()

ChaCha20::~ChaCha20

(

)

Destructor to clean up private memory.

Definition at line 353 of file chacha20.cpp.

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Member Function Documentation

Crypt()

void ChaCha20::Crypt ( Span< const std::byte >  in_bytes, 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 321 of file chacha20.cpp.

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Keystream()

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

noexcept

outputs the keystream to out.

Definition at line 298 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 118 of file chacha20.h.

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SetKey()

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

noexcept

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

Definition at line 357 of file chacha20.cpp.

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Member Data Documentation

KEYLEN

constexpr unsigned ChaCha20::KEYLEN = ChaCha20Aligned::KEYLEN

staticconstexpr

Expected key length in constructor and SetKey.

Definition at line 97 of file chacha20.h.

m_aligned

ChaCha20Aligned ChaCha20::m_aligned

private

Definition at line 91 of file chacha20.h.

m_buffer

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

private

Definition at line 92 of file chacha20.h.

m_bufleft

unsigned ChaCha20::m_bufleft {0}

private

Definition at line 93 of file chacha20.h.

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

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