AEADChaCha20Poly1305 (crypto/chacha20poly1305.h)

Provides AEAD ChaCha20-Poly1305 encryption and forward-secure wrapper for secure messaging.

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// Distributed under the MIT software license, see the accompanying
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#ifndef BITCOIN_CRYPTO_CHACHA20POLY1305_H
#define BITCOIN_CRYPTO_CHACHA20POLY1305_H

#include <cstddef>
#include <cstdint>
#include <span>

#include <crypto/chacha20.h>
#include <crypto/poly1305.h>

/** The AEAD_CHACHA20_POLY1305 authenticated encryption algorithm from RFC8439 section 2.8. */
class AEADChaCha20Poly1305
{
    /** Internal stream cipher. */
    ChaCha20 m_chacha20;

public:
    /** Expected size of key argum

... (truncated -- full source via MCP)