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

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

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

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

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

FSChaCha20Poly1305() [2/3]

FSChaCha20Poly1305::FSChaCha20Poly1305 ( FSChaCha20Poly1305 &&  )

delete

FSChaCha20Poly1305() [3/3]

FSChaCha20Poly1305::FSChaCha20Poly1305 ( 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.

Member Function Documentation

Decrypt() [1/2]

bool FSChaCha20Poly1305::Decrypt ( Span< const std::byte >  cipher, Span< const std::byte >  aad, 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.

Here is the call graph for this function:

Here is the caller graph for this function:

Decrypt() [2/2]

bool FSChaCha20Poly1305::Decrypt ( Span< const std::byte >  cipher, Span< const std::byte >  aad, Span< std::byte >  plain1, 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.

Encrypt() [1/2]

void FSChaCha20Poly1305::Encrypt ( Span< const std::byte >  plain, Span< const std::byte >  aad, 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.

Here is the call graph for this function:

Here is the caller graph for this function:

Encrypt() [2/2]

void FSChaCha20Poly1305::Encrypt ( Span< const std::byte >  plain1, Span< const std::byte >  plain2, Span< const std::byte >  aad, 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.

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.

Here is the call graph for this function:

operator=() [1/2]

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

delete

operator=() [2/2]

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

delete

Member Data Documentation

EXPANSION

constexpr auto FSChaCha20Poly1305::EXPANSION = AEADChaCha20Poly1305::EXPANSION

staticconstexpr

Expansion when encrypting.

Definition at line 105 of file chacha20poly1305.h.

KEYLEN

constexpr 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.

---

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

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