Source code
Revision control
Copy as Markdown
Other Tools
/**
* Abstraction for a combined KEM public and private key.
*
* (C) 2024 Jack Lloyd
* 2024 Fabian Albert, René Meusel - Rohde & Schwarz Cybersecurity
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#ifndef BOTAN_HYBRID_KEM_H_
#define BOTAN_HYBRID_KEM_H_
#include <botan/pk_algs.h>
#include <botan/pk_keys.h>
#include <botan/pubkey.h>
#include <memory>
#include <vector>
namespace Botan {
/**
* @brief Abstraction for a combined KEM public key.
*
* Two or more KEM public keys are combined into a single KEM public key. Derived classes
* must implement the abstract methods to provide the encryption operation, e.g. by
* specifying how encryption results are combined to the ciphertext and how a KEM combiner
* is applied to derive the shared secret using the individual shared secrets, ciphertexts,
* and other context information.
*/
class BOTAN_TEST_API Hybrid_PublicKey : public virtual Public_Key {
public:
/**
* @brief Constructor for a list of multiple KEM public keys.
*
* To use KEX algorithms use the KEX_to_KEM_Adapter_PublicKey.
* @param public_keys List of public keys to combine
*/
explicit Hybrid_PublicKey(std::vector<std::unique_ptr<Public_Key>> public_keys);
Hybrid_PublicKey(Hybrid_PublicKey&&) = default;
Hybrid_PublicKey(const Hybrid_PublicKey&) = delete;
Hybrid_PublicKey& operator=(Hybrid_PublicKey&&) = default;
Hybrid_PublicKey& operator=(const Hybrid_PublicKey&) = delete;
~Hybrid_PublicKey() override = default;
size_t estimated_strength() const override { return m_estimated_strength; }
size_t key_length() const override { return m_key_length; }
bool check_key(RandomNumberGenerator& rng, bool strong) const override;
std::vector<uint8_t> raw_public_key_bits() const override;
/**
* @brief Return the public key bits of this hybrid key as the concatenated
* bytes of the individual public keys (without encoding).
*
* @return the public key bytes
*/
std::vector<uint8_t> public_key_bits() const override { return raw_public_key_bits(); }
bool supports_operation(PublicKeyOperation op) const override;
/// @returns the public keys combined in this hybrid key
const std::vector<std::unique_ptr<Public_Key>>& public_keys() const { return m_pks; }
protected:
// Default constructor used for virtual inheritance to prevent, that the derived class
// calls the constructor twice.
Hybrid_PublicKey() = default;
/**
* @brief Helper function for generate_another. Generate a new private key for each
* public key in this hybrid key.
*/
std::vector<std::unique_ptr<Private_Key>> generate_other_sks_from_pks(RandomNumberGenerator& rng) const;
private:
std::vector<std::unique_ptr<Public_Key>> m_pks;
size_t m_key_length;
size_t m_estimated_strength;
};
BOTAN_DIAGNOSTIC_PUSH
BOTAN_DIAGNOSTIC_IGNORE_INHERITED_VIA_DOMINANCE
/**
* @brief Abstraction for a combined KEM private key.
*
* Two or more KEM private keys are combined into a single KEM private key. Derived classes
* must implement the abstract methods to provide the decryption operation, e.g. by
* specifying how a KEM combiner is applied to derive the shared secret using the
* individual shared secrets, ciphertexts, and other context information.
*/
class BOTAN_TEST_API Hybrid_PrivateKey : virtual public Private_Key {
public:
Hybrid_PrivateKey(const Hybrid_PrivateKey&) = delete;
Hybrid_PrivateKey& operator=(const Hybrid_PrivateKey&) = delete;
Hybrid_PrivateKey(Hybrid_PrivateKey&&) = default;
Hybrid_PrivateKey& operator=(Hybrid_PrivateKey&&) = default;
~Hybrid_PrivateKey() override = default;
/**
* @brief Constructor for a list of multiple KEM private keys.
*
* To use KEX algorithms use the KEX_to_KEM_Adapter_PrivateKey.
* @param private_keys List of private keys to combine
*/
Hybrid_PrivateKey(std::vector<std::unique_ptr<Private_Key>> private_keys);
/// Disabled by default
secure_vector<uint8_t> private_key_bits() const override;
/// @returns the private keys combined in this hybrid key
const std::vector<std::unique_ptr<Private_Key>>& private_keys() const { return m_sks; }
bool check_key(RandomNumberGenerator& rng, bool strong) const override;
protected:
static std::vector<std::unique_ptr<Public_Key>> extract_public_keys(
const std::vector<std::unique_ptr<Private_Key>>& private_keys);
private:
std::vector<std::unique_ptr<Private_Key>> m_sks;
};
BOTAN_DIAGNOSTIC_POP
} // namespace Botan
#endif