FSChaCha20Poly1305 Class Reference

Forward-secure wrapper around AEADChaCha20Poly1305. More...

#include <chacha20poly1305.h>

Collaboration diagram for FSChaCha20Poly1305:

Public Member Functions
	FSChaCha20Poly1305 (const FSChaCha20Poly1305 &)=delete
	FSChaCha20Poly1305 (FSChaCha20Poly1305 &&)=delete
FSChaCha20Poly1305 &	operator= (const FSChaCha20Poly1305 &)=delete
FSChaCha20Poly1305 &	operator= (FSChaCha20Poly1305 &&)=delete
	FSChaCha20Poly1305 (std::span< const std::byte > key, uint32_t rekey_interval) noexcept
	Construct an FSChaCha20Poly1305 cipher that rekeys every rekey_interval operations.
void	Encrypt (std::span< const std::byte > plain, std::span< const std::byte > aad, std::span< std::byte > cipher) noexcept
	Encrypt a message with a specified aad.
void	Encrypt (std::span< const std::byte > plain1, std::span< const std::byte > plain2, std::span< const std::byte > aad, std::span< std::byte > cipher) noexcept
	Encrypt a message (given split into plain1 + plain2) with a specified aad.
bool	Decrypt (std::span< const std::byte > cipher, std::span< const std::byte > aad, std::span< std::byte > plain) noexcept
	Decrypt a message with a specified aad.
bool	Decrypt (std::span< const std::byte > cipher, std::span< const std::byte > aad, std::span< std::byte > plain1, std::span< std::byte > plain2) noexcept
	Decrypt a message with a specified aad and split the result.

Static Public Attributes
static constexpr auto	KEYLEN = AEADChaCha20Poly1305::KEYLEN
	Length of keys expected by the constructor.
static constexpr auto	EXPANSION = AEADChaCha20Poly1305::EXPANSION
	Expansion when encrypting.

Private Member Functions
void	NextPacket () noexcept
	Update counters (and if necessary, key) to transition to the next message.

Private Attributes
AEADChaCha20Poly1305	m_aead
	Internal AEAD.
const uint32_t	m_rekey_interval
	Every how many iterations this cipher rekeys.
uint32_t	m_packet_counter {0}
	The number of encryptions/decryptions since the last rekey.
uint64_t	m_rekey_counter {0}
	The number of rekeys performed so far.

Detailed Description

Forward-secure wrapper around AEADChaCha20Poly1305.

This implements an AEAD which automatically increments the nonce on every encryption or decryption, and cycles keys after a predetermined number of encryptions or decryptions.

See BIP324 for details.

Definition at line 82 of file chacha20poly1305.h.

Constructor & Destructor Documentation

FSChaCha20Poly1305() [1/3]

FSChaCha20Poly1305::FSChaCha20Poly1305 ( const FSChaCha20Poly1305 & )

delete

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FSChaCha20Poly1305() [2/3]

FSChaCha20Poly1305::FSChaCha20Poly1305 ( FSChaCha20Poly1305 && )

delete

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FSChaCha20Poly1305() [3/3]

FSChaCha20Poly1305::FSChaCha20Poly1305 ( std::span< const std::byte > key, uint32_t rekey_interval )

inlinenoexcept

Construct an FSChaCha20Poly1305 cipher that rekeys every rekey_interval operations.

Definition at line 114 of file chacha20poly1305.h.

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Member Function Documentation

Decrypt() [1/2]

bool FSChaCha20Poly1305::Decrypt ( std::span< const std::byte > cipher, std::span< const std::byte > aad, std::span< std::byte > plain )

inlinenoexcept

Decrypt a message with a specified aad.

Returns true if valid.

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

Definition at line 136 of file chacha20poly1305.h.

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Decrypt() [2/2]

bool FSChaCha20Poly1305::Decrypt ( std::span< const std::byte > cipher, std::span< const std::byte > aad, std::span< std::byte > plain1, std::span< std::byte > plain2 )

noexcept

Decrypt a message with a specified aad and split the result.

Returns true if valid.

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

Definition at line 130 of file chacha20poly1305.cpp.

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Encrypt() [1/2]

void FSChaCha20Poly1305::Encrypt ( std::span< const std::byte > plain, std::span< const std::byte > aad, std::span< std::byte > cipher )

inlinenoexcept

Encrypt a message with a specified aad.

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

Definition at line 121 of file chacha20poly1305.h.

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Encrypt() [2/2]

void FSChaCha20Poly1305::Encrypt ( std::span< const std::byte > plain1, std::span< const std::byte > plain2, std::span< const std::byte > aad, std::span< std::byte > cipher )

noexcept

Encrypt a message (given split into plain1 + plain2) with a specified aad.

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

Definition at line 124 of file chacha20poly1305.cpp.

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NextPacket()

void FSChaCha20Poly1305::NextPacket ( )

privatenoexcept

Update counters (and if necessary, key) to transition to the next message.

Definition at line 106 of file chacha20poly1305.cpp.

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operator=() [1/2]

FSChaCha20Poly1305 & FSChaCha20Poly1305::operator= ( const FSChaCha20Poly1305 & )

delete

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operator=() [2/2]

FSChaCha20Poly1305 & FSChaCha20Poly1305::operator= ( FSChaCha20Poly1305 && )

delete

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Member Data Documentation

EXPANSION

auto FSChaCha20Poly1305::EXPANSION = AEADChaCha20Poly1305::EXPANSION

staticconstexpr

Expansion when encrypting.

Definition at line 105 of file chacha20poly1305.h.

KEYLEN

auto FSChaCha20Poly1305::KEYLEN = AEADChaCha20Poly1305::KEYLEN

staticconstexpr

Length of keys expected by the constructor.

Definition at line 102 of file chacha20poly1305.h.

m_aead

AEADChaCha20Poly1305 FSChaCha20Poly1305::m_aead

private

Internal AEAD.

Definition at line 86 of file chacha20poly1305.h.

m_packet_counter

uint32_t FSChaCha20Poly1305::m_packet_counter {0}

private

The number of encryptions/decryptions since the last rekey.

Definition at line 92 of file chacha20poly1305.h.

m_rekey_counter

uint64_t FSChaCha20Poly1305::m_rekey_counter {0}

private

The number of rekeys performed so far.

Definition at line 95 of file chacha20poly1305.h.

m_rekey_interval

const uint32_t FSChaCha20Poly1305::m_rekey_interval

private

Every how many iterations this cipher rekeys.

Definition at line 89 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