/*

* ECDSA

* (C) 2007 Falko Strenzke, FlexSecure GmbH

*          Manuel Hartl, FlexSecure GmbH

* (C) 2008-2010 Jack Lloyd

*

* Botan is released under the Simplified BSD License (see license.txt)

*/

#ifndef BOTAN_ECC_PUBLIC_KEY_BASE_H_

#define BOTAN_ECC_PUBLIC_KEY_BASE_H_

#include <botan/ec_group.h>

#include <botan/pk_keys.h>

namespace Botan {

/**

* This class represents abstract ECC public keys. When encoding a key

* via an encoder that can be accessed via the corresponding member

* functions, the key will decide upon its internally stored encoding

* information whether to encode itself with or without domain

* parameters, or using the domain parameter oid. Furthermore, a public

* key without domain parameters can be decoded. In that case, it

* cannot be used for verification until its domain parameters are set

* by calling the corresponding member function.

*/

class BOTAN_PUBLIC_API(2,0) EC_PublicKey : public virtual Public_Key

   {

   public:

      EC_PublicKey(const EC_PublicKey& other) = default;

      EC_PublicKey& operator=(const EC_PublicKey& other) = default;

      virtual ~EC_PublicKey() = default;

      /**

      * Get the public point of this key.

      * @throw Invalid_State is thrown if the

      * domain parameters of this point are not set

      * @result the public point of this key

      */

      const PointGFp& public_point() const { return m_public_key; }

      AlgorithmIdentifier algorithm_identifier() const override;

      std::vector<uint8_t> public_key_bits() const override;

      bool check_key(RandomNumberGenerator& rng,

                     bool strong) const override;

      /**

      * Get the domain parameters of this key.

      * @throw Invalid_State is thrown if the

      * domain parameters of this point are not set

      * @result the domain parameters of this key

      */

      const EC_Group& domain() const { return m_domain_params; }

      /**

      * Set the domain parameter encoding to be used when encoding this key.

      * @param enc the encoding to use

      */

      void set_parameter_encoding(EC_Group_Encoding enc);

      /**

      * Set the point encoding method to be used when encoding this key.

      * @param enc the encoding to use

      */

      void set_point_encoding(PointGFp::Compression_Type enc);

      /**

      * Return the DER encoding of this keys domain in whatever format

      * is preset for this particular key

      */

      std::vector<uint8_t> DER_domain() const

         { return domain().DER_encode(domain_format()); }

      /**

      * Get the domain parameter encoding to be used when encoding this key.

      * @result the encoding to use

      */

      EC_Group_Encoding domain_format() const

         { return m_domain_encoding; }

      /**

      * Get the point encoding method to be used when encoding this key.

      * @result the encoding to use

      */

      PointGFp::Compression_Type point_encoding() const

         { return m_point_encoding; }

      size_t key_length() const override;

      size_t estimated_strength() const override;

   protected:

      /**

      * Create a public key.

      * @param dom_par EC domain parameters

      * @param pub_point public point on the curve

      */

      EC_PublicKey(const EC_Group& dom_par,

                   const PointGFp& pub_point);

      /**

      * Load a public key.

      * @param alg_id the X.509 algorithm identifier

      * @param key_bits DER encoded public key bits

      */

      EC_PublicKey(const AlgorithmIdentifier& alg_id,

                   const std::vector<uint8_t>& key_bits);

      EC_PublicKey() : m_domain_params{}, m_public_key{}, m_domain_encoding(EC_Group_Encoding::Explicit)

      {}

      EC_Group m_domain_params;

      PointGFp m_public_key;

      EC_Group_Encoding m_domain_encoding;

      PointGFp::Compression_Type m_point_encoding = PointGFp::UNCOMPRESSED;

   };

/**

* This abstract class represents ECC private keys

*/

class BOTAN_PUBLIC_API(2,0) EC_PrivateKey : public virtual EC_PublicKey,

                                public virtual Private_Key

   {

   public:

      secure_vector<uint8_t> private_key_bits() const override;

      /**

      * Get the private key value of this key object.

      * @result the private key value of this key object

      */

      const BigInt& private_value() const;

      EC_PrivateKey(const EC_PrivateKey& other) = default;

      EC_PrivateKey& operator=(const EC_PrivateKey& other) = default;

      ~EC_PrivateKey() = default;

   protected:

      /*

      * If x=0, creates a new private key in the domain

      * using the given rng. If with_modular_inverse is set,

      * the public key will be calculated by multiplying

      * the base point with the modular inverse of

      * x (as in ECGDSA and ECKCDSA), otherwise by

      * multiplying directly with x (as in ECDSA).

      */

      EC_PrivateKey(RandomNumberGenerator& rng,

                    const EC_Group& domain,

                    const BigInt& x,

                    bool with_modular_inverse=false);

      /*

      * Creates a new private key object from the

      * ECPrivateKey structure given in key_bits.

      * If with_modular_inverse is set,

      * the public key will be calculated by multiplying

      * the base point with the modular inverse of

      * x (as in ECGDSA and ECKCDSA), otherwise by

      * multiplying directly with x (as in ECDSA).

      */

      EC_PrivateKey(const AlgorithmIdentifier& alg_id,

                    const secure_vector<uint8_t>& key_bits,

                    bool with_modular_inverse=false);

      EC_PrivateKey() = default;

      BigInt m_private_key;

   };

}

#endif