/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 *
 * (c) ZeroTier, Inc.
 * https://www.zerotier.com/
 */

#ifndef ZT_CERTIFICATEOFOWNERSHIP_HPP
#define ZT_CERTIFICATEOFOWNERSHIP_HPP

#include "Address.hpp"
#include "Buffer.hpp"
#include "Constants.hpp"
#include "Credential.hpp"
#include "ECC.hpp"
#include "Identity.hpp"
#include "InetAddress.hpp"
#include "MAC.hpp"

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

// Max things per CertificateOfOwnership
#define ZT_CERTIFICATEOFOWNERSHIP_MAX_THINGS 16

// Maximum size of a thing's value field in bytes
#define ZT_CERTIFICATEOFOWNERSHIP_MAX_THING_VALUE_SIZE 16

namespace ZeroTier {

class RuntimeEnvironment;

/**
 * Certificate indicating ownership of a network identifier
 */
class CertificateOfOwnership : public Credential {
  public:
	static inline Credential::Type credentialType()
	{
		return Credential::CREDENTIAL_TYPE_COO;
	}

	enum Thing { THING_NULL = 0, THING_MAC_ADDRESS = 1, THING_IPV4_ADDRESS = 2, THING_IPV6_ADDRESS = 3 };

	CertificateOfOwnership()
	{
		memset(reinterpret_cast<void*>(this), 0, sizeof(CertificateOfOwnership));
	}

	CertificateOfOwnership(const uint64_t nwid, const int64_t ts, const Address& issuedTo, const uint32_t id)
	{
		memset(reinterpret_cast<void*>(this), 0, sizeof(CertificateOfOwnership));
		_networkId = nwid;
		_ts = ts;
		_id = id;
		_issuedTo = issuedTo;
	}

	inline uint64_t networkId() const
	{
		return _networkId;
	}
	inline int64_t timestamp() const
	{
		return _ts;
	}
	inline uint32_t id() const
	{
		return _id;
	}
	inline unsigned int thingCount() const
	{
		return (unsigned int)_thingCount;
	}

	inline Thing thingType(const unsigned int i) const
	{
		return (Thing)_thingTypes[i];
	}
	inline const uint8_t* thingValue(const unsigned int i) const
	{
		return _thingValues[i];
	}

	inline const Address& issuedTo() const
	{
		return _issuedTo;
	}

	inline bool owns(const InetAddress& ip) const
	{
		if (ip.ss_family == AF_INET) {
			return this->_owns(THING_IPV4_ADDRESS, &(reinterpret_cast<const struct sockaddr_in*>(&ip)->sin_addr.s_addr), 4);
		}
		if (ip.ss_family == AF_INET6) {
			return this->_owns(THING_IPV6_ADDRESS, reinterpret_cast<const struct sockaddr_in6*>(&ip)->sin6_addr.s6_addr, 16);
		}
		return false;
	}

	inline bool owns(const MAC& mac) const
	{
		uint8_t tmp[6];
		mac.copyTo(tmp, 6);
		return this->_owns(THING_MAC_ADDRESS, tmp, 6);
	}

	inline void addThing(const InetAddress& ip)
	{
		if (_thingCount >= ZT_CERTIFICATEOFOWNERSHIP_MAX_THINGS) {
			return;
		}
		if (ip.ss_family == AF_INET) {
			_thingTypes[_thingCount] = THING_IPV4_ADDRESS;
			memcpy(_thingValues[_thingCount], &(reinterpret_cast<const struct sockaddr_in*>(&ip)->sin_addr.s_addr), 4);
			++_thingCount;
		}
		else if (ip.ss_family == AF_INET6) {
			_thingTypes[_thingCount] = THING_IPV6_ADDRESS;
			memcpy(_thingValues[_thingCount], reinterpret_cast<const struct sockaddr_in6*>(&ip)->sin6_addr.s6_addr, 16);
			++_thingCount;
		}
	}

	inline void addThing(const MAC& mac)
	{
		if (_thingCount >= ZT_CERTIFICATEOFOWNERSHIP_MAX_THINGS) {
			return;
		}
		_thingTypes[_thingCount] = THING_MAC_ADDRESS;
		mac.copyTo(_thingValues[_thingCount], 6);
		++_thingCount;
	}

	/**
	 * @param signer Signing identity, must have private key
	 * @return True if signature was successful
	 */
	inline bool sign(const Identity& signer)
	{
		if (signer.hasPrivate()) {
			Buffer<sizeof(CertificateOfOwnership) + 64> tmp;
			_signedBy = signer.address();
			this->serialize(tmp, true);
			_signature = signer.sign(tmp.data(), tmp.size());
			return true;
		}
		return false;
	}

	/**
	 * @param RR Runtime environment to allow identity lookup for signedBy
	 * @param tPtr Thread pointer to be handed through to any callbacks called as a result of this call
	 * @return 0 == OK, 1 == waiting for WHOIS, -1 == BAD signature
	 */
	int verify(const RuntimeEnvironment* RR, void* tPtr) const;

	template <unsigned int C> inline void serialize(Buffer<C>& b, const bool forSign = false) const
	{
		if (forSign) {
			b.append((uint64_t)0x7f7f7f7f7f7f7f7fULL);
		}

		b.append(_networkId);
		b.append(_ts);
		b.append(_flags);
		b.append(_id);
		b.append((uint16_t)_thingCount);
		for (unsigned int i = 0, j = _thingCount; i < j; ++i) {
			b.append((uint8_t)_thingTypes[i]);
			b.append(_thingValues[i], ZT_CERTIFICATEOFOWNERSHIP_MAX_THING_VALUE_SIZE);
		}

		_issuedTo.appendTo(b);
		_signedBy.appendTo(b);
		if (! forSign) {
			b.append((uint8_t)1);						// 1 == Ed25519
			b.append((uint16_t)ZT_ECC_SIGNATURE_LEN);	// length of signature
			b.append(_signature.data, ZT_ECC_SIGNATURE_LEN);
		}

		b.append((uint16_t)0);	 // length of additional fields, currently 0

		if (forSign) {
			b.append((uint64_t)0x7f7f7f7f7f7f7f7fULL);
		}
	}

	template <unsigned int C> inline unsigned int deserialize(const Buffer<C>& b, unsigned int startAt = 0)
	{
		unsigned int p = startAt;

		*this = CertificateOfOwnership();

		_networkId = b.template at<uint64_t>(p);
		p += 8;
		_ts = b.template at<uint64_t>(p);
		p += 8;
		_flags = b.template at<uint64_t>(p);
		p += 8;
		_id = b.template at<uint32_t>(p);
		p += 4;
		_thingCount = b.template at<uint16_t>(p);
		p += 2;
		for (unsigned int i = 0, j = _thingCount; i < j; ++i) {
			if (i < ZT_CERTIFICATEOFOWNERSHIP_MAX_THINGS) {
				_thingTypes[i] = (uint8_t)b[p++];
				memcpy(_thingValues[i], b.field(p, ZT_CERTIFICATEOFOWNERSHIP_MAX_THING_VALUE_SIZE), ZT_CERTIFICATEOFOWNERSHIP_MAX_THING_VALUE_SIZE);
				p += ZT_CERTIFICATEOFOWNERSHIP_MAX_THING_VALUE_SIZE;
			}
		}

		_issuedTo.setTo(b.field(p, ZT_ADDRESS_LENGTH), ZT_ADDRESS_LENGTH);
		p += ZT_ADDRESS_LENGTH;
		_signedBy.setTo(b.field(p, ZT_ADDRESS_LENGTH), ZT_ADDRESS_LENGTH);
		p += ZT_ADDRESS_LENGTH;
		if (b[p++] == 1) {
			if (b.template at<uint16_t>(p) != ZT_ECC_SIGNATURE_LEN) {
				throw ZT_EXCEPTION_INVALID_SERIALIZED_DATA_INVALID_CRYPTOGRAPHIC_TOKEN;
			}
			p += 2;
			memcpy(_signature.data, b.field(p, ZT_ECC_SIGNATURE_LEN), ZT_ECC_SIGNATURE_LEN);
			p += ZT_ECC_SIGNATURE_LEN;
		}
		else {
			p += 2 + b.template at<uint16_t>(p);
		}

		p += 2 + b.template at<uint16_t>(p);
		if (p > b.size()) {
			throw ZT_EXCEPTION_INVALID_SERIALIZED_DATA_OVERFLOW;
		}

		return (p - startAt);
	}

	// Provides natural sort order by ID
	inline bool operator<(const CertificateOfOwnership& coo) const
	{
		return (_id < coo._id);
	}

	inline bool operator==(const CertificateOfOwnership& coo) const
	{
		return (memcmp(this, &coo, sizeof(CertificateOfOwnership)) == 0);
	}
	inline bool operator!=(const CertificateOfOwnership& coo) const
	{
		return (memcmp(this, &coo, sizeof(CertificateOfOwnership)) != 0);
	}

  private:
	bool _owns(const Thing& t, const void* v, unsigned int l) const;

	uint64_t _networkId;
	int64_t _ts;
	uint64_t _flags;
	uint32_t _id;
	uint16_t _thingCount;
	uint8_t _thingTypes[ZT_CERTIFICATEOFOWNERSHIP_MAX_THINGS];
	uint8_t _thingValues[ZT_CERTIFICATEOFOWNERSHIP_MAX_THINGS][ZT_CERTIFICATEOFOWNERSHIP_MAX_THING_VALUE_SIZE];
	Address _issuedTo;
	Address _signedBy;
	ECC::Signature _signature;
};

}	// namespace ZeroTier

#endif