Struct PacketCipher 

pub struct PacketCipher { /* private fields */ }

Packet encryptor with automatic nonce management and replay protection

Performance

• Uses counter-based nonces (no RNG syscalls)
• Caches cipher instance for reuse
• Pre-allocates output buffers with known capacity

Implementations

impl PacketCipher

pub fn new(key: DataChannelKey) -> Self

Create a new packet cipher

pub fn encrypt(&mut self, plaintext: &[u8]) -> Result<Vec<u8>>

Encrypt a packet

Returns: [8-byte packet_id | ciphertext | 16-byte tag]

pub fn encrypt_into( &mut self, plaintext: &[u8], output: &mut Vec<u8>, ) -> Result<usize>

Encrypt a packet into a pre-allocated buffer

Returns the total bytes written (header + ciphertext + tag). Buffer should be cleared before calling.

pub fn decrypt(&mut self, packet: &[u8]) -> Result<Vec<u8>>

Decrypt a packet with replay protection

pub fn tx_counter(&self) -> u64

Get current TX counter (for debugging/stats)