AEADChaCha20Poly1305 Class Reference

The AEAD_CHACHA20_POLY1305 authenticated encryption algorithm from RFC8439 section 2.8. More...

#include <chacha20poly1305.h>

Collaboration diagram for AEADChaCha20Poly1305:

Public Types
using	Nonce96 = ChaCha20::Nonce96
	96-bit nonce type. More...

Public Member Functions
	AEADChaCha20Poly1305 (Span< const std::byte > key) noexcept
	Initialize an AEAD instance with a specified 32-byte key. More...
void	SetKey (Span< const std::byte > key) noexcept
	Switch to another 32-byte key. More...
void	Encrypt (Span< const std::byte > plain, Span< const std::byte > aad, Nonce96 nonce, Span< std::byte > cipher) noexcept
	Encrypt a message with a specified 96-bit nonce and aad. More...
void	Encrypt (Span< const std::byte > plain1, Span< const std::byte > plain2, Span< const std::byte > aad, Nonce96 nonce, Span< std::byte > cipher) noexcept
	Encrypt a message (given split into plain1 + plain2) with a specified 96-bit nonce and aad. More...
bool	Decrypt (Span< const std::byte > cipher, Span< const std::byte > aad, Nonce96 nonce, Span< std::byte > plain) noexcept
	Decrypt a message with a specified 96-bit nonce and aad. More...
bool	Decrypt (Span< const std::byte > cipher, Span< const std::byte > aad, Nonce96 nonce, Span< std::byte > plain1, Span< std::byte > plain2) noexcept
	Decrypt a message with a specified 96-bit nonce and aad and split the result. More...
void	Keystream (Nonce96 nonce, Span< std::byte > keystream) noexcept
	Get a number of keystream bytes from the underlying stream cipher. More...

Static Public Attributes
static constexpr unsigned	KEYLEN = 32
	Expected size of key argument in constructor. More...
static constexpr unsigned	EXPANSION = Poly1305::TAGLEN
	Expansion when encrypting. More...

Private Attributes
ChaCha20	m_chacha20
	Internal stream cipher. More...

Detailed Description

The AEAD_CHACHA20_POLY1305 authenticated encryption algorithm from RFC8439 section 2.8.

Definition at line 16 of file chacha20poly1305.h.

Member Typedef Documentation

Nonce96

using AEADChaCha20Poly1305::Nonce96 = ChaCha20::Nonce96

96-bit nonce type.

Definition at line 35 of file chacha20poly1305.h.

Constructor & Destructor Documentation

AEADChaCha20Poly1305()

AEADChaCha20Poly1305::AEADChaCha20Poly1305 ( Span< const std::byte >  key )

noexcept

Initialize an AEAD instance with a specified 32-byte key.

Definition at line 16 of file chacha20poly1305.cpp.

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Member Function Documentation

Decrypt() [1/2]

bool AEADChaCha20Poly1305::Decrypt ( Span< const std::byte >  cipher, Span< const std::byte >  aad, Nonce96  nonce, Span< std::byte >  plain  )

inlinenoexcept

Decrypt a message with a specified 96-bit nonce and aad.

Returns true if valid.

Requires cipher.size() = plain.size() + EXPANSION.

Definition at line 56 of file chacha20poly1305.h.

Decrypt() [2/2]

bool AEADChaCha20Poly1305::Decrypt ( Span< const std::byte >  cipher, Span< const std::byte >  aad, Nonce96  nonce, Span< std::byte >  plain1, Span< std::byte >  plain2  )

noexcept

Decrypt a message with a specified 96-bit nonce and aad and split the result.

Returns true if valid.

Requires cipher.size() = plain1.size() + plain2.size() + EXPANSION.

Definition at line 83 of file chacha20poly1305.cpp.

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Encrypt() [1/2]

void AEADChaCha20Poly1305::Encrypt ( Span< const std::byte >  plain, Span< const std::byte >  aad, Nonce96  nonce, Span< std::byte >  cipher  )

inlinenoexcept

Encrypt a message with a specified 96-bit nonce and aad.

Requires cipher.size() = plain.size() + EXPANSION.

Definition at line 41 of file chacha20poly1305.h.

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Encrypt() [2/2]

void AEADChaCha20Poly1305::Encrypt ( Span< const std::byte >  plain1, Span< const std::byte >  plain2, Span< const std::byte >  aad, Nonce96  nonce, Span< std::byte >  cipher  )

noexcept

Encrypt a message (given split into plain1 + plain2) with a specified 96-bit nonce and aad.

Requires cipher.size() = plain1.size() + plain2.size() + EXPANSION.

Definition at line 69 of file chacha20poly1305.cpp.

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Keystream()

void AEADChaCha20Poly1305::Keystream ( Nonce96  nonce, Span< std::byte >  keystream  )

noexcept

Get a number of keystream bytes from the underlying stream cipher.

This is equivalent to Encrypt() with plain set to that many zero bytes, and dropping the last EXPANSION bytes off the result.

Definition at line 99 of file chacha20poly1305.cpp.

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SetKey()

void AEADChaCha20Poly1305::SetKey ( Span< const std::byte >  key )

noexcept

Switch to another 32-byte key.

Definition at line 21 of file chacha20poly1305.cpp.

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Member Data Documentation

EXPANSION

constexpr unsigned AEADChaCha20Poly1305::EXPANSION = Poly1305::TAGLEN

staticconstexpr

Expansion when encrypting.

Definition at line 26 of file chacha20poly1305.h.

KEYLEN

constexpr unsigned AEADChaCha20Poly1305::KEYLEN = 32

staticconstexpr

Expected size of key argument in constructor.

Definition at line 23 of file chacha20poly1305.h.

m_chacha20

ChaCha20 AEADChaCha20Poly1305::m_chacha20

private

Internal stream cipher.

Definition at line 19 of file chacha20poly1305.h.

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

• src/crypto/chacha20poly1305.h
• src/crypto/chacha20poly1305.cpp