ptth/bare_minimum_crypto/cpp/signing_key.h

#pragma once

#include <optional>
#include <stdint.h>
#include <string>
#include <vector>

#include "expiring_signature.h"
#include "time_helpers.h"

namespace BareMinimumCrypto {
	using namespace std;
	
	struct SigningKeyFile {
		vector <uint8_t> salt;
		Instant time_created;
		vector <uint8_t> pubkey;
		
		vector <uint8_t> to_msgpack () const;
		static optional <SigningKeyFile> try_from_msgpack (const vector <uint8_t> & msg);
	};
	
	struct SigningKey {
		vector <uint8_t> pk;
		vector <uint8_t> sk;
		
		SigningKey ();
		
		// This doesn't fsync, so it's possible to lose the key due to a power outage
		// or filesystem nonsense right after this function returns.
		// It also doesn't do the rename trick. The caller may do that.
		
		static optional <SigningKey> generate_to_file (const string & file_path, const string & passphrase);
		
		static optional <SigningKey> load_from_file (const string & file_path, const string & passphrase);
		
		static optional <SigningKeyFile> check_file (const string & file_path);
		
		vector <uint8_t> pubkey () const;
		vector <uint8_t> pub_to_msgpack () const;
		
		optional <ExpiringSignature> sign (
			const vector <uint8_t> & payload,
			TimeRange tr
		) const;
		
		optional <ExpiringSignature> sign_key (const SigningKey & k, Instant now) const;
		optional <ExpiringSignature> sign_data (const vector <uint8_t> & v, Instant now) const;
	};
}