/*

 * SLH-DSA - Stateless Hash-Based Digital Signature Standard - FIPS 205

 * Based on the creative commons (CC0 1.0) SPHINCS+ reference implementation by the

 * designers (https://github.com/sphincs/sphincsplus/)

 *

 * (C) 2023 Jack Lloyd

 *     2023 Fabian Albert, René Meusel, Rohde & Schwarz Cybersecurity

 *

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

 **/

#ifndef BOTAN_SPHINCS_PLUS_H_

#define BOTAN_SPHINCS_PLUS_H_

#include <botan/pk_keys.h>

#include <botan/sp_parameters.h>

#include <memory>

#include <vector>

namespace Botan {

class SphincsPlus_PublicKeyInternal;

class SphincsPlus_PrivateKeyInternal;

/**

 * @brief An SLH-DSA (or SPHINCS+ Round 3.1) public key.

 *

 * For more information see the documentation of SphincsPlus_PrivateKey.

 */

class BOTAN_PUBLIC_API(3, 1) SphincsPlus_PublicKey : public virtual Public_Key {

   public:

      SphincsPlus_PublicKey(std::span<const uint8_t> pub_key, Sphincs_Parameter_Set type, Sphincs_Hash_Type hash);

      SphincsPlus_PublicKey(std::span<const uint8_t> pub_key, Sphincs_Parameters params);

      SphincsPlus_PublicKey(const AlgorithmIdentifier& alg_id, std::span<const uint8_t> key_bits);

      ~SphincsPlus_PublicKey() override;

      SphincsPlus_PublicKey(const SphincsPlus_PublicKey& other) = default;

      SphincsPlus_PublicKey(SphincsPlus_PublicKey&& other) = default;

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

      SphincsPlus_PublicKey& operator=(SphincsPlus_PublicKey&& other) = default;

      size_t key_length() const override;

      std::string algo_name() const override;

      size_t estimated_strength() const override;

      AlgorithmIdentifier algorithm_identifier() const override;

      OID object_identifier() const override;

      bool check_key(RandomNumberGenerator& rng, bool strong) const override;

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

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

      std::unique_ptr<Private_Key> generate_another(RandomNumberGenerator& rng) const final;

      std::unique_ptr<PK_Ops::Verification> create_verification_op(std::string_view params,

                                                                   std::string_view provider) const override;

      std::unique_ptr<PK_Ops::Verification> create_x509_verification_op(const AlgorithmIdentifier& signature_algorithm,

                                                                        std::string_view provider) const override;

      bool supports_operation(PublicKeyOperation op) const override;

   protected:

      SphincsPlus_PublicKey() = default;

      std::shared_ptr<SphincsPlus_PublicKeyInternal> m_public;  // NOLINT(*non-private-member-variable*)

};

BOTAN_DIAGNOSTIC_PUSH

BOTAN_DIAGNOSTIC_IGNORE_INHERITED_VIA_DOMINANCE

/**

 * @brief An SLH-DSA private key.

 *

 * This class represents an SLH-DSA private key (or a SPHINCS+ Round 3.1 private key).

 * Supported are all parameter sets defined in FIPS 205, Section 11. Parameter

 * sets are specified using the Sphincs_Parameter_Set and

 * Sphincs_Hash_Type enums, for example SLH-DSA-SHA2-128s is defined as

 * Sphincs_Parameter_Set::SLHDSA128Small and Sphincs_Hash_Type::Sha256.

 *

 * For legacy usage of SPHINCS+ Round 3 (not recommended), the parameter sets

 * Sphincs128Small, ..., Sphincs256Fast are used.

 *

 * Note that the parameter sets denoted as 'small' optimize for signature size

 * at the expense of signing speed, whereas 'fast' trades larger signatures for

 * faster signing speeds.

 *

 * This implementation is based on the SPHINCS+

 * https://github.com/sphincs/sphincsplus/commit/06f42f47491085ac879a72b486ca8edb10891963

 * which implements SPHINCS+ Specification Round 3.1 (https://sphincs.org/data/sphincs+-r3.1-specification.pdf).

 * The used tweaked hashes are implemented according to the variant 'simple' ('robust' is not supported).

 */

class BOTAN_PUBLIC_API(3, 1) SphincsPlus_PrivateKey final : public virtual SphincsPlus_PublicKey,

                                                            public virtual Private_Key {

   public:

      SphincsPlus_PrivateKey(std::span<const uint8_t> private_key, Sphincs_Parameter_Set type, Sphincs_Hash_Type hash);

      SphincsPlus_PrivateKey(std::span<const uint8_t> private_key, Sphincs_Parameters params);

      SphincsPlus_PrivateKey(const AlgorithmIdentifier& alg_id, std::span<const uint8_t> key_bits);

      SphincsPlus_PrivateKey(RandomNumberGenerator& rng, Sphincs_Parameter_Set type, Sphincs_Hash_Type hash);

      SphincsPlus_PrivateKey(RandomNumberGenerator& rng, Sphincs_Parameters params);

      ~SphincsPlus_PrivateKey() override;

      SphincsPlus_PrivateKey(const SphincsPlus_PrivateKey& other) = default;

      SphincsPlus_PrivateKey(SphincsPlus_PrivateKey&& other) = default;

      SphincsPlus_PrivateKey& operator=(const SphincsPlus_PrivateKey& other) = delete;

      SphincsPlus_PrivateKey& operator=(SphincsPlus_PrivateKey&& other) = delete;

      secure_vector<uint8_t> private_key_bits() const override;

      secure_vector<uint8_t> raw_private_key_bits() const override;

      std::unique_ptr<Public_Key> public_key() const override;

      std::unique_ptr<PK_Ops::Signature> create_signature_op(RandomNumberGenerator& rng,

                                                             std::string_view params,

                                                             std::string_view provider) const override;

   private:

      std::shared_ptr<SphincsPlus_PrivateKeyInternal> m_private;

};

BOTAN_DIAGNOSTIC_POP

}  // namespace Botan

#endif