[thirdparty/pdns.git] / pdns / dnscrypt.hh

/*
 * This file is part of PowerDNS or dnsdist.
 * Copyright -- PowerDNS.COM B.V. and its contributors
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * In addition, for the avoidance of any doubt, permission is granted to
 * link this program with OpenSSL and to (re)distribute the binaries
 * produced as the result of such linking.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#pragma once
#include "config.h"

#ifndef HAVE_DNSCRYPT

class DNSCryptQuery
{
};

#else

#include <memory>
#include <string>
#include <vector>
#include <arpa/inet.h>

#include <sodium.h>

#include "dnsname.hh"

#define DNSCRYPT_PROVIDER_PUBLIC_KEY_SIZE (crypto_sign_ed25519_PUBLICKEYBYTES)
#define DNSCRYPT_PROVIDER_PRIVATE_KEY_SIZE (crypto_sign_ed25519_SECRETKEYBYTES)
#define DNSCRYPT_SIGNATURE_SIZE (crypto_sign_ed25519_BYTES)

#define DNSCRYPT_PUBLIC_KEY_SIZE (crypto_box_curve25519xsalsa20poly1305_PUBLICKEYBYTES)
#define DNSCRYPT_PRIVATE_KEY_SIZE (crypto_box_curve25519xsalsa20poly1305_SECRETKEYBYTES)
#define DNSCRYPT_NONCE_SIZE (crypto_box_curve25519xsalsa20poly1305_NONCEBYTES)
#define DNSCRYPT_BEFORENM_SIZE (crypto_box_curve25519xsalsa20poly1305_BEFORENMBYTES)
#define DNSCRYPT_MAC_SIZE (crypto_box_curve25519xsalsa20poly1305_MACBYTES)

#ifdef HAVE_CRYPTO_BOX_CURVE25519XCHACHA20POLY1305_EASY
static_assert(crypto_box_curve25519xsalsa20poly1305_PUBLICKEYBYTES == crypto_box_curve25519xchacha20poly1305_PUBLICKEYBYTES, "DNSCrypt public key size should be the same for all exchange versions");
static_assert(crypto_box_curve25519xsalsa20poly1305_SECRETKEYBYTES == crypto_box_curve25519xchacha20poly1305_SECRETKEYBYTES, "DNSCrypt private key size should be the same for all exchange versions");
static_assert(crypto_box_curve25519xchacha20poly1305_NONCEBYTES == crypto_box_curve25519xsalsa20poly1305_NONCEBYTES, "DNSCrypt nonce size should be the same for all exchange versions");
static_assert(crypto_box_curve25519xsalsa20poly1305_MACBYTES == crypto_box_curve25519xchacha20poly1305_MACBYTES, "DNSCrypt MAC size should be the same for all exchange versions");
static_assert(crypto_box_curve25519xchacha20poly1305_BEFORENMBYTES == crypto_box_curve25519xsalsa20poly1305_BEFORENMBYTES, "DNSCrypt BEFORENM size should be the same for all exchange versions");
#endif /* HAVE_CRYPTO_BOX_CURVE25519XCHACHA20POLY1305_EASY */

#define DNSCRYPT_CERT_MAGIC_SIZE (4)
#define DNSCRYPT_CERT_MAGIC_VALUE { 0x44, 0x4e, 0x53, 0x43 }
#define DNSCRYPT_CERT_PROTOCOL_MINOR_VERSION_VALUE { 0x00, 0x00 }
#define DNSCRYPT_CLIENT_MAGIC_SIZE (8)
#define DNSCRYPT_RESOLVER_MAGIC { 0x72, 0x36, 0x66, 0x6e, 0x76, 0x57, 0x6a, 0x38 }
#define DNSCRYPT_RESOLVER_MAGIC_SIZE (8)
#define DNSCRYPT_PADDED_BLOCK_SIZE (64)
#define DNSCRYPT_MAX_TCP_PADDING_SIZE (256)
#define DNSCRYPT_MAX_RESPONSE_PADDING_SIZE (256)
#define DNSCRYPT_MAX_RESPONSE_PADDING_AND_MAC_SIZE (DNSCRYPT_MAX_RESPONSE_PADDING_SIZE + DNSCRYPT_MAC_SIZE)

/* "The client must check for new certificates every hour", so let's use one hour TTL */
#define DNSCRYPT_CERTIFICATE_RESPONSE_TTL (3600)

static_assert(DNSCRYPT_CLIENT_MAGIC_SIZE <= DNSCRYPT_PUBLIC_KEY_SIZE, "DNSCrypt Client Nonce size should be smaller or equal to public key size.");

#define DNSCRYPT_CERT_ES_VERSION1_VALUE { 0x00, 0x01 }
#define DNSCRYPT_CERT_ES_VERSION2_VALUE { 0x00, 0x02 }

class DNSCryptContext;

struct DNSCryptCertSignedData
{
  unsigned char resolverPK[DNSCRYPT_PROVIDER_PUBLIC_KEY_SIZE];
  unsigned char clientMagic[DNSCRYPT_CLIENT_MAGIC_SIZE];
  uint32_t serial;
  uint32_t tsStart;
  uint32_t tsEnd;
};

class DNSCryptCert
{
public:
  uint32_t getSerial() const
  {
    return ntohl(signedData.serial);
  }
  uint32_t getTSStart() const
  {
    return signedData.tsStart;
  }
  uint32_t getTSEnd() const
  {
    return signedData.tsEnd;
  }
  bool isValid(time_t now) const
  {
    return ntohl(getTSStart()) <= static_cast<uint32_t>(now) && static_cast<uint32_t>(now) <= ntohl(getTSEnd());
  }
  unsigned char magic[DNSCRYPT_CERT_MAGIC_SIZE];
  unsigned char esVersion[2];
  unsigned char protocolMinorVersion[2];
  unsigned char signature[DNSCRYPT_SIGNATURE_SIZE];
  struct DNSCryptCertSignedData signedData;
};

static_assert((sizeof(DNSCryptCertSignedData) + DNSCRYPT_SIGNATURE_SIZE) == 116, "Dnscrypt cert signed data size + signature size should be 116!");
static_assert(sizeof(DNSCryptCert) == 124, "Dnscrypt cert size should be 124!");

struct DNSCryptQueryHeader
{
  unsigned char clientMagic[DNSCRYPT_CLIENT_MAGIC_SIZE];
  unsigned char clientPK[DNSCRYPT_PUBLIC_KEY_SIZE];
  unsigned char clientNonce[DNSCRYPT_NONCE_SIZE / 2];
};

static_assert(sizeof(DNSCryptQueryHeader) == 52, "Dnscrypt query header size should be 52!");

struct DNSCryptResponseHeader
{
  const unsigned char resolverMagic[DNSCRYPT_RESOLVER_MAGIC_SIZE] = DNSCRYPT_RESOLVER_MAGIC;
  unsigned char nonce[DNSCRYPT_NONCE_SIZE];
};

typedef enum {
  VERSION1,
  VERSION2
} DNSCryptExchangeVersion;

class DNSCryptPrivateKey
{
public:
  DNSCryptPrivateKey();
  ~DNSCryptPrivateKey();
  void loadFromFile(const std::string& keyFile);
  void saveToFile(const std::string& keyFile) const;

  unsigned char key[DNSCRYPT_PRIVATE_KEY_SIZE];
};

struct DNSCryptCertificatePair
{
  unsigned char publicKey[DNSCRYPT_PUBLIC_KEY_SIZE];
  DNSCryptCert cert;
  DNSCryptPrivateKey privateKey;
  bool active;
};

class DNSCryptQuery
{
public:
  DNSCryptQuery(const std::shared_ptr<DNSCryptContext>& ctx): d_ctx(ctx)
  {
  }
  ~DNSCryptQuery();

  bool isValid() const
  {
    return d_valid;
  }

  const DNSName& getQName() const
  {
    return d_qname;
  }

  uint16_t getID() const
  {
    return d_id;
  }

  const unsigned char* getClientMagic() const
  {
    return d_header.clientMagic;
  }

  bool isEncrypted() const
  {
    return d_encrypted;
  }

  void setCertificatePair(const std::shared_ptr<DNSCryptCertificatePair>& pair)
  {
    d_pair = pair;
  }

  void parsePacket(char* packet, uint16_t packetSize, bool tcp, uint16_t* decryptedQueryLen, time_t now);
  void getDecrypted(bool tcp, char* packet, uint16_t packetSize, uint16_t* decryptedQueryLen);
  void getCertificateResponse(time_t now, std::vector<uint8_t>& response) const;
  int encryptResponse(char* response, uint16_t responseLen, uint16_t responseSize, bool tcp, uint16_t* encryptedResponseLen);

  static const size_t s_minUDPLength = 256;

private:
  DNSCryptExchangeVersion getVersion() const;
#ifdef HAVE_CRYPTO_BOX_EASY_AFTERNM
  int computeSharedKey();
#endif /* HAVE_CRYPTO_BOX_EASY_AFTERNM */
  void fillServerNonce(unsigned char* dest) const;
  uint16_t computePaddingSize(uint16_t unpaddedLen, size_t maxLen) const;
  bool parsePlaintextQuery(const char * packet, uint16_t packetSize);
  bool isEncryptedQuery(const char * packet, uint16_t packetSize, bool tcp, time_t now);

  DNSCryptQueryHeader d_header;
#ifdef HAVE_CRYPTO_BOX_EASY_AFTERNM
  unsigned char d_sharedKey[crypto_box_BEFORENMBYTES];
#endif /* HAVE_CRYPTO_BOX_EASY_AFTERNM */
  DNSName d_qname;
  std::shared_ptr<DNSCryptContext> d_ctx{nullptr};
  std::shared_ptr<DNSCryptCertificatePair> d_pair{nullptr};
  uint16_t d_id{0};
  uint16_t d_len{0};
  uint16_t d_paddedLen{0};
  bool d_encrypted{false};
  bool d_valid{false};

#ifdef HAVE_CRYPTO_BOX_EASY_AFTERNM
  bool d_sharedKeyComputed{false};
#endif /* HAVE_CRYPTO_BOX_EASY_AFTERNM */
};

class DNSCryptContext
{
public:
  static void generateProviderKeys(unsigned char publicKey[DNSCRYPT_PROVIDER_PUBLIC_KEY_SIZE], unsigned char privateKey[DNSCRYPT_PROVIDER_PRIVATE_KEY_SIZE]);
  static std::string getProviderFingerprint(unsigned char publicKey[DNSCRYPT_PROVIDER_PUBLIC_KEY_SIZE]);
  static void generateCertificate(uint32_t serial, time_t begin, time_t end, const DNSCryptExchangeVersion& version, const unsigned char providerPrivateKey[DNSCRYPT_PROVIDER_PRIVATE_KEY_SIZE], DNSCryptPrivateKey& privateKey, DNSCryptCert& cert);
  static void saveCertFromFile(const DNSCryptCert& cert, const std::string&filename);
  static std::string certificateDateToStr(uint32_t date);
  static void generateResolverKeyPair(DNSCryptPrivateKey& privK, unsigned char pubK[DNSCRYPT_PUBLIC_KEY_SIZE]);
  static void setExchangeVersion(const DNSCryptExchangeVersion& version,  unsigned char esVersion[sizeof(DNSCryptCert::esVersion)]);
  static DNSCryptExchangeVersion getExchangeVersion(const unsigned char esVersion[sizeof(DNSCryptCert::esVersion)]);
  static DNSCryptExchangeVersion getExchangeVersion(const DNSCryptCert& cert);

  DNSCryptContext(const std::string& pName, const std::string& certFile, const std::string& keyFile);
  DNSCryptContext(const std::string& pName, const DNSCryptCert& certificate, const DNSCryptPrivateKey& pKey);

  void loadNewCertificate(const std::string& certFile, const std::string& keyFile, bool active=true);
  void addNewCertificate(const DNSCryptCert& newCert, const DNSCryptPrivateKey& newKey, bool active=true);
  void markActive(uint32_t serial);
  void markInactive(uint32_t serial);
  void removeInactiveCertificate(uint32_t serial);
  std::vector<std::shared_ptr<DNSCryptCertificatePair>> getCertificates() { return certs; };
  const DNSName& getProviderName() const { return providerName; }

  int encryptQuery(char* query, uint16_t queryLen, uint16_t querySize, const unsigned char clientPublicKey[DNSCRYPT_PUBLIC_KEY_SIZE], const DNSCryptPrivateKey& clientPrivateKey, const unsigned char clientNonce[DNSCRYPT_NONCE_SIZE / 2], bool tcp, uint16_t* encryptedResponseLen, const std::shared_ptr<DNSCryptCert>& cert) const;
  bool magicMatchesAPublicKey(DNSCryptQuery& query, time_t now);
  void getCertificateResponse(time_t now, const DNSName& qname, uint16_t qid, std::vector<uint8_t>& response);

private:
  static void computePublicKeyFromPrivate(const DNSCryptPrivateKey& privK, unsigned char pubK[DNSCRYPT_PUBLIC_KEY_SIZE]);
  static void loadCertFromFile(const std::string&filename, DNSCryptCert& dest);

  pthread_rwlock_t d_lock;
  std::vector<std::shared_ptr<DNSCryptCertificatePair>> certs;
  DNSName providerName;
};

bool generateDNSCryptCertificate(const std::string& providerPrivateKeyFile, uint32_t serial, time_t begin, time_t end, DNSCryptExchangeVersion version, DNSCryptCert& certOut, DNSCryptPrivateKey& keyOut);

#endif
Commit	Line	Data
12471842 PL	1	/*
	2	* This file is part of PowerDNS or dnsdist.
	3	* Copyright -- PowerDNS.COM B.V. and its contributors
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of version 2 of the GNU General Public License as
	7	* published by the Free Software Foundation.
	8	*
	9	* In addition, for the avoidance of any doubt, permission is granted to
	10	* link this program with OpenSSL and to (re)distribute the binaries
	11	* produced as the result of such linking.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
	21	*/
11e1e08b RG	22	#pragma once
	23	#include "config.h"
	24
77f6a2a0 RG	25	#ifndef HAVE_DNSCRYPT
	26
	27	class DNSCryptQuery
	28	{
	29	};
	30
	31	#else
11e1e08b RG	32
	33	#include <memory>
	34	#include <string>
	35	#include <vector>
43234e76 RG	36	#include <arpa/inet.h>
43234e76 RG	37
11e1e08b RG	38	#include <sodium.h>
	39
	40	#include "dnsname.hh"
	41
	42	#define DNSCRYPT_PROVIDER_PUBLIC_KEY_SIZE (crypto_sign_ed25519_PUBLICKEYBYTES)
	43	#define DNSCRYPT_PROVIDER_PRIVATE_KEY_SIZE (crypto_sign_ed25519_SECRETKEYBYTES)
43234e76 RG	44	#define DNSCRYPT_SIGNATURE_SIZE (crypto_sign_ed25519_BYTES)
43234e76 RG	45
11e1e08b RG	46	#define DNSCRYPT_PUBLIC_KEY_SIZE (crypto_box_curve25519xsalsa20poly1305_PUBLICKEYBYTES)
	47	#define DNSCRYPT_PRIVATE_KEY_SIZE (crypto_box_curve25519xsalsa20poly1305_SECRETKEYBYTES)
	48	#define DNSCRYPT_NONCE_SIZE (crypto_box_curve25519xsalsa20poly1305_NONCEBYTES)
	49	#define DNSCRYPT_BEFORENM_SIZE (crypto_box_curve25519xsalsa20poly1305_BEFORENMBYTES)
11e1e08b	50	#define DNSCRYPT_MAC_SIZE (crypto_box_curve25519xsalsa20poly1305_MACBYTES)
43234e76 RG	51
	52	#ifdef HAVE_CRYPTO_BOX_CURVE25519XCHACHA20POLY1305_EASY
	53	static_assert(crypto_box_curve25519xsalsa20poly1305_PUBLICKEYBYTES == crypto_box_curve25519xchacha20poly1305_PUBLICKEYBYTES, "DNSCrypt public key size should be the same for all exchange versions");
	54	static_assert(crypto_box_curve25519xsalsa20poly1305_SECRETKEYBYTES == crypto_box_curve25519xchacha20poly1305_SECRETKEYBYTES, "DNSCrypt private key size should be the same for all exchange versions");
	55	static_assert(crypto_box_curve25519xchacha20poly1305_NONCEBYTES == crypto_box_curve25519xsalsa20poly1305_NONCEBYTES, "DNSCrypt nonce size should be the same for all exchange versions");
	56	static_assert(crypto_box_curve25519xsalsa20poly1305_MACBYTES == crypto_box_curve25519xchacha20poly1305_MACBYTES, "DNSCrypt MAC size should be the same for all exchange versions");
	57	static_assert(crypto_box_curve25519xchacha20poly1305_BEFORENMBYTES == crypto_box_curve25519xsalsa20poly1305_BEFORENMBYTES, "DNSCrypt BEFORENM size should be the same for all exchange versions");
	58	#endif /* HAVE_CRYPTO_BOX_CURVE25519XCHACHA20POLY1305_EASY */
	59
11e1e08b RG	60	#define DNSCRYPT_CERT_MAGIC_SIZE (4)
11e1e08b RG	61	#define DNSCRYPT_CERT_MAGIC_VALUE { 0x44, 0x4e, 0x53, 0x43 }
11e1e08b RG	62	#define DNSCRYPT_CERT_PROTOCOL_MINOR_VERSION_VALUE { 0x00, 0x00 }
	63	#define DNSCRYPT_CLIENT_MAGIC_SIZE (8)
	64	#define DNSCRYPT_RESOLVER_MAGIC { 0x72, 0x36, 0x66, 0x6e, 0x76, 0x57, 0x6a, 0x38 }
	65	#define DNSCRYPT_RESOLVER_MAGIC_SIZE (8)
	66	#define DNSCRYPT_PADDED_BLOCK_SIZE (64)
	67	#define DNSCRYPT_MAX_TCP_PADDING_SIZE (256)
	68	#define DNSCRYPT_MAX_RESPONSE_PADDING_SIZE (256)
	69	#define DNSCRYPT_MAX_RESPONSE_PADDING_AND_MAC_SIZE (DNSCRYPT_MAX_RESPONSE_PADDING_SIZE + DNSCRYPT_MAC_SIZE)
	70
	71	/* "The client must check for new certificates every hour", so let's use one hour TTL */
	72	#define DNSCRYPT_CERTIFICATE_RESPONSE_TTL (3600)
	73
43234e76 RG	74	static_assert(DNSCRYPT_CLIENT_MAGIC_SIZE <= DNSCRYPT_PUBLIC_KEY_SIZE, "DNSCrypt Client Nonce size should be smaller or equal to public key size.");
	75
	76	#define DNSCRYPT_CERT_ES_VERSION1_VALUE { 0x00, 0x01 }
	77	#define DNSCRYPT_CERT_ES_VERSION2_VALUE { 0x00, 0x02 }
11e1e08b	78
43234e76	79	class DNSCryptContext;
11e1e08b	80
43234e76	81	struct DNSCryptCertSignedData
11e1e08b RG	82	{
	83	unsigned char resolverPK[DNSCRYPT_PROVIDER_PUBLIC_KEY_SIZE];
	84	unsigned char clientMagic[DNSCRYPT_CLIENT_MAGIC_SIZE];
	85	uint32_t serial;
	86	uint32_t tsStart;
	87	uint32_t tsEnd;
	88	};
	89
43234e76	90	class DNSCryptCert
11e1e08b	91	{
43234e76 RG	92	public:
	93	uint32_t getSerial() const
	94	{
b7bd0317	95	return ntohl(signedData.serial);
43234e76 RG	96	}
	97	uint32_t getTSStart() const
	98	{
	99	return signedData.tsStart;
	100	}
	101	uint32_t getTSEnd() const
	102	{
	103	return signedData.tsEnd;
	104	}
	105	bool isValid(time_t now) const
	106	{
638a7c34	107	return ntohl(getTSStart()) <= static_cast<uint32_t>(now) && static_cast<uint32_t>(now) <= ntohl(getTSEnd());
43234e76	108	}
a683e8bd	109	unsigned char magic[DNSCRYPT_CERT_MAGIC_SIZE];
11e1e08b RG	110	unsigned char esVersion[2];
	111	unsigned char protocolMinorVersion[2];
	112	unsigned char signature[DNSCRYPT_SIGNATURE_SIZE];
43234e76	113	struct DNSCryptCertSignedData signedData;
11e1e08b RG	114	};
11e1e08b RG	115
43234e76 RG	116	static_assert((sizeof(DNSCryptCertSignedData) + DNSCRYPT_SIGNATURE_SIZE) == 116, "Dnscrypt cert signed data size + signature size should be 116!");
43234e76 RG	117	static_assert(sizeof(DNSCryptCert) == 124, "Dnscrypt cert size should be 124!");
11e1e08b	118
43234e76	119	struct DNSCryptQueryHeader
11e1e08b RG	120	{
	121	unsigned char clientMagic[DNSCRYPT_CLIENT_MAGIC_SIZE];
	122	unsigned char clientPK[DNSCRYPT_PUBLIC_KEY_SIZE];
	123	unsigned char clientNonce[DNSCRYPT_NONCE_SIZE / 2];
	124	};
	125
43234e76	126	static_assert(sizeof(DNSCryptQueryHeader) == 52, "Dnscrypt query header size should be 52!");
11e1e08b	127
43234e76	128	struct DNSCryptResponseHeader
8089cbe5 RG	129	{
	130	const unsigned char resolverMagic[DNSCRYPT_RESOLVER_MAGIC_SIZE] = DNSCRYPT_RESOLVER_MAGIC;
	131	unsigned char nonce[DNSCRYPT_NONCE_SIZE];
	132	};
	133
43234e76 RG	134	typedef enum {
	135	VERSION1,
	136	VERSION2
	137	} DNSCryptExchangeVersion;
	138
	139	class DNSCryptPrivateKey
8089cbe5 RG	140	{
8089cbe5 RG	141	public:
43234e76 RG	142	DNSCryptPrivateKey();
43234e76 RG	143	~DNSCryptPrivateKey();
8089cbe5 RG	144	void loadFromFile(const std::string& keyFile);
	145	void saveToFile(const std::string& keyFile) const;
	146
	147	unsigned char key[DNSCRYPT_PRIVATE_KEY_SIZE];
	148	};
	149
43234e76 RG	150	struct DNSCryptCertificatePair
	151	{
	152	unsigned char publicKey[DNSCRYPT_PUBLIC_KEY_SIZE];
	153	DNSCryptCert cert;
	154	DNSCryptPrivateKey privateKey;
	155	bool active;
	156	};
	157
	158	class DNSCryptQuery
11e1e08b RG	159	{
11e1e08b RG	160	public:
f3b1a1ef	161	DNSCryptQuery(const std::shared_ptr<DNSCryptContext>& ctx): d_ctx(ctx)
43234e76 RG	162	{
	163	}
	164	~DNSCryptQuery();
	165
	166	bool isValid() const
	167	{
	168	return d_valid;
	169	}
	170
	171	const DNSName& getQName() const
8089cbe5	172	{
43234e76	173	return d_qname;
8089cbe5	174	}
43234e76 RG	175
	176	uint16_t getID() const
	177	{
	178	return d_id;
	179	}
	180
	181	const unsigned char* getClientMagic() const
	182	{
	183	return d_header.clientMagic;
	184	}
	185
	186	bool isEncrypted() const
	187	{
	188	return d_encrypted;
	189	}
	190
f3b1a1ef	191	void setCertificatePair(const std::shared_ptr<DNSCryptCertificatePair>& pair)
43234e76 RG	192	{
	193	d_pair = pair;
	194	}
	195
	196	void parsePacket(char* packet, uint16_t packetSize, bool tcp, uint16_t* decryptedQueryLen, time_t now);
	197	void getDecrypted(bool tcp, char* packet, uint16_t packetSize, uint16_t* decryptedQueryLen);
	198	void getCertificateResponse(time_t now, std::vector<uint8_t>& response) const;
	199	int encryptResponse(char* response, uint16_t responseLen, uint16_t responseSize, bool tcp, uint16_t* encryptedResponseLen);
	200
	201	static const size_t s_minUDPLength = 256;
	202
	203	private:
	204	DNSCryptExchangeVersion getVersion() const;
00ffb1c2	205	#ifdef HAVE_CRYPTO_BOX_EASY_AFTERNM
43234e76	206	int computeSharedKey();
00ffb1c2	207	#endif /* HAVE_CRYPTO_BOX_EASY_AFTERNM */
43234e76 RG	208	void fillServerNonce(unsigned char* dest) const;
	209	uint16_t computePaddingSize(uint16_t unpaddedLen, size_t maxLen) const;
	210	bool parsePlaintextQuery(const char * packet, uint16_t packetSize);
	211	bool isEncryptedQuery(const char * packet, uint16_t packetSize, bool tcp, time_t now);
8089cbe5	212
43234e76	213	DNSCryptQueryHeader d_header;
00ffb1c2	214	#ifdef HAVE_CRYPTO_BOX_EASY_AFTERNM
43234e76	215	unsigned char d_sharedKey[crypto_box_BEFORENMBYTES];
00ffb1c2	216	#endif /* HAVE_CRYPTO_BOX_EASY_AFTERNM */
43234e76 RG	217	DNSName d_qname;
	218	std::shared_ptr<DNSCryptContext> d_ctx{nullptr};
	219	std::shared_ptr<DNSCryptCertificatePair> d_pair{nullptr};
	220	uint16_t d_id{0};
	221	uint16_t d_len{0};
f3b1a1ef	222	uint16_t d_paddedLen{0};
43234e76 RG	223	bool d_encrypted{false};
	224	bool d_valid{false};
	225
00ffb1c2	226	#ifdef HAVE_CRYPTO_BOX_EASY_AFTERNM
43234e76	227	bool d_sharedKeyComputed{false};
00ffb1c2	228	#endif /* HAVE_CRYPTO_BOX_EASY_AFTERNM */
11e1e08b RG	229	};
11e1e08b RG	230
43234e76	231	class DNSCryptContext
11e1e08b RG	232	{
	233	public:
	234	static void generateProviderKeys(unsigned char publicKey[DNSCRYPT_PROVIDER_PUBLIC_KEY_SIZE], unsigned char privateKey[DNSCRYPT_PROVIDER_PRIVATE_KEY_SIZE]);
	235	static std::string getProviderFingerprint(unsigned char publicKey[DNSCRYPT_PROVIDER_PUBLIC_KEY_SIZE]);
43234e76 RG	236	static void generateCertificate(uint32_t serial, time_t begin, time_t end, const DNSCryptExchangeVersion& version, const unsigned char providerPrivateKey[DNSCRYPT_PROVIDER_PRIVATE_KEY_SIZE], DNSCryptPrivateKey& privateKey, DNSCryptCert& cert);
43234e76 RG	237	static void saveCertFromFile(const DNSCryptCert& cert, const std::string&filename);
11e1e08b	238	static std::string certificateDateToStr(uint32_t date);
43234e76 RG	239	static void generateResolverKeyPair(DNSCryptPrivateKey& privK, unsigned char pubK[DNSCRYPT_PUBLIC_KEY_SIZE]);
	240	static void setExchangeVersion(const DNSCryptExchangeVersion& version, unsigned char esVersion[sizeof(DNSCryptCert::esVersion)]);
	241	static DNSCryptExchangeVersion getExchangeVersion(const unsigned char esVersion[sizeof(DNSCryptCert::esVersion)]);
	242	static DNSCryptExchangeVersion getExchangeVersion(const DNSCryptCert& cert);
11e1e08b	243
43234e76 RG	244	DNSCryptContext(const std::string& pName, const std::string& certFile, const std::string& keyFile);
43234e76 RG	245	DNSCryptContext(const std::string& pName, const DNSCryptCert& certificate, const DNSCryptPrivateKey& pKey);
11e1e08b	246
43234e76 RG	247	void loadNewCertificate(const std::string& certFile, const std::string& keyFile, bool active=true);
	248	void addNewCertificate(const DNSCryptCert& newCert, const DNSCryptPrivateKey& newKey, bool active=true);
	249	void markActive(uint32_t serial);
	250	void markInactive(uint32_t serial);
	251	void removeInactiveCertificate(uint32_t serial);
	252	std::vector<std::shared_ptr<DNSCryptCertificatePair>> getCertificates() { return certs; };
	253	const DNSName& getProviderName() const { return providerName; }
11e1e08b	254
f3b1a1ef	255	int encryptQuery(char* query, uint16_t queryLen, uint16_t querySize, const unsigned char clientPublicKey[DNSCRYPT_PUBLIC_KEY_SIZE], const DNSCryptPrivateKey& clientPrivateKey, const unsigned char clientNonce[DNSCRYPT_NONCE_SIZE / 2], bool tcp, uint16_t* encryptedResponseLen, const std::shared_ptr<DNSCryptCert>& cert) const;
43234e76 RG	256	bool magicMatchesAPublicKey(DNSCryptQuery& query, time_t now);
43234e76 RG	257	void getCertificateResponse(time_t now, const DNSName& qname, uint16_t qid, std::vector<uint8_t>& response);
11e1e08b RG	258
11e1e08b RG	259	private:
43234e76 RG	260	static void computePublicKeyFromPrivate(const DNSCryptPrivateKey& privK, unsigned char pubK[DNSCRYPT_PUBLIC_KEY_SIZE]);
43234e76 RG	261	static void loadCertFromFile(const std::string&filename, DNSCryptCert& dest);
11e1e08b	262
43234e76 RG	263	pthread_rwlock_t d_lock;
	264	std::vector<std::shared_ptr<DNSCryptCertificatePair>> certs;
	265	DNSName providerName;
11e1e08b RG	266	};
11e1e08b RG	267
43234e76	268	bool generateDNSCryptCertificate(const std::string& providerPrivateKeyFile, uint32_t serial, time_t begin, time_t end, DNSCryptExchangeVersion version, DNSCryptCert& certOut, DNSCryptPrivateKey& keyOut);
6bb38cd6	269
11e1e08b	270	#endif