esphome::noise::NoiseResponderHandshake Class Reference

Sans-IO responder side of a Noise_NNpsk0_25519_ChaChaPoly_SHA256 handshake. More...

#include <noise_handshake.h>

Public Types
enum class	Action : uint8_t { ACTION_READ , ACTION_WRITE , ACTION_SPLIT , ACTION_FAILED }

Public Member Functions
	NoiseResponderHandshake ()=default
	~NoiseResponderHandshake ()
	NoiseResponderHandshake (const NoiseResponderHandshake &)=delete
NoiseResponderHandshake &	operator= (const NoiseResponderHandshake &)=delete
int	init (const psk_t &psk, const uint8_t *prologue, size_t prologue_len)
	Create and start the handshake with the given PSK and prologue.
Action	action () const
	ACTION_FAILED is the catch-all: returned before init(), after split() has released the state, and when noise-c reports a failed handshake.
int	read_message (uint8_t *data, size_t len)
	Process one received handshake message.
int	write_message (uint8_t *out, size_t capacity, size_t &out_len)
	Produce the next handshake message into out; out_len receives its size and is zero on error.
int	split (NoiseCipherState *&send_cipher, NoiseCipherState *&recv_cipher)
	Hand out the transport ciphers and free the handshake state.

Protected Member Functions
int	fail_init_ (int err)
	Release a half-initialized state so a failed init() leaves the object as if init() was never called.

Protected Attributes
NoiseHandshakeState *	handshake_ {nullptr}

Detailed Description

Sans-IO responder side of a Noise_NNpsk0_25519_ChaChaPoly_SHA256 handshake.

Owns only the noise-c handshake state; the caller moves the raw handshake messages (no framing) over its own transport, driven by action(): read_message() while READ, write_message() while WRITE, then split() to take ownership of the transport ciphers. All methods return a noise-c error code, 0 on success. Called outside their action() step (before init(), after split()) the message methods return a noise-c error rather than crashing; the library checks its state argument.

Methods are deliberately small separate functions so callers on tight stacks (RP2040 core0 scratch bank) never pay for more than one branch; the curve25519 step alone needs ~2KB of stack.

Definition at line 27 of file noise_handshake.h.

Member Enumeration Documentation

Action

enum class esphome::noise::NoiseResponderHandshake::Action : uint8_t

strong

Enumerator
ACTION_READ
ACTION_WRITE
ACTION_SPLIT
ACTION_FAILED

Definition at line 31 of file noise_handshake.h.

Constructor & Destructor Documentation

NoiseResponderHandshake() [1/2]

esphome::noise::NoiseResponderHandshake::NoiseResponderHandshake ( )

default

~NoiseResponderHandshake()

esphome::noise::NoiseResponderHandshake::~NoiseResponderHandshake

(

)

Definition at line 16 of file noise_handshake.cpp.

NoiseResponderHandshake() [2/2]

esphome::noise::NoiseResponderHandshake::NoiseResponderHandshake ( const NoiseResponderHandshake & )

delete

Member Function Documentation

action()

NoiseResponderHandshake::Action esphome::noise::NoiseResponderHandshake::action ( ) const

nodiscard

ACTION_FAILED is the catch-all: returned before init(), after split() has released the state, and when noise-c reports a failed handshake.

Definition at line 73 of file noise_handshake.cpp.

fail_init_()

int esphome::noise::NoiseResponderHandshake::fail_init_ ( int err )

protected

Release a half-initialized state so a failed init() leaves the object as if init() was never called.

Definition at line 67 of file noise_handshake.cpp.

init()

int esphome::noise::NoiseResponderHandshake::init ( const psk_t & psk, const uint8_t * prologue, size_t prologue_len )

nodiscard

Create and start the handshake with the given PSK and prologue.

A repeated call frees the previous handshake state and starts over.

Definition at line 23 of file noise_handshake.cpp.

operator=()

NoiseResponderHandshake & esphome::noise::NoiseResponderHandshake::operator= ( const NoiseResponderHandshake & )

delete

read_message()

int esphome::noise::NoiseResponderHandshake::read_message ( uint8_t * data, size_t len )

nodiscard

Process one received handshake message.

The buffer is consumed in place: noise-c decrypts into it and zeroes it before returning.

Definition at line 94 of file noise_handshake.cpp.

split()

int esphome::noise::NoiseResponderHandshake::split ( NoiseCipherState *& send_cipher, NoiseCipherState *& recv_cipher )

nodiscard

Hand out the transport ciphers and free the handshake state.

The caller owns both cipher states and must free them with noise_cipherstate_free(); both are set to nullptr on error.

Definition at line 112 of file noise_handshake.cpp.

write_message()

int esphome::noise::NoiseResponderHandshake::write_message ( uint8_t * out, size_t capacity, size_t & out_len )

nodiscard

Produce the next handshake message into out; out_len receives its size and is zero on error.

Definition at line 101 of file noise_handshake.cpp.

Field Documentation

handshake_

NoiseHandshakeState* esphome::noise::NoiseResponderHandshake::handshake_ {nullptr}

protected

Definition at line 59 of file noise_handshake.h.

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

• esphome/components/noise/noise_handshake.h
• esphome/components/noise/noise_handshake.cpp