Source code
Revision control
Copy as Markdown
Other Tools
/*
* FrodoKEM constants
*
* The Fellowship of the FrodoKEM:
* (C) 2023 Jack Lloyd
* 2023 René Meusel, Amos Treiber - Rohde & Schwarz Cybersecurity
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#ifndef BOTAN_FRODOKEM_CONSTANTS_H_
#define BOTAN_FRODOKEM_CONSTANTS_H_
#include <botan/frodo_mode.h>
#include <botan/internal/frodo_types.h>
#include <memory>
#include <string>
#include <vector>
namespace Botan {
class XOF;
class BOTAN_TEST_API FrodoKEMConstants final {
public:
FrodoKEMConstants(FrodoKEMMode mode);
~FrodoKEMConstants();
FrodoKEMConstants(const FrodoKEMConstants& other) : FrodoKEMConstants(other.m_mode) {}
FrodoKEMConstants(FrodoKEMConstants&& other) = default;
FrodoKEMConstants& operator=(const FrodoKEMConstants& other) = delete;
FrodoKEMConstants& operator=(FrodoKEMConstants&& other) = default;
FrodoKEMMode mode() const { return m_mode; }
size_t cdf_table_len() const { return m_cdf_table.size(); }
uint16_t cdf_table_at(size_t i) const { return m_cdf_table.at(i); }
size_t estimated_strength() const { return m_nist_strength; }
size_t n() const { return m_n; }
size_t b() const { return m_b; } // extracted bits
size_t d() const { return m_d; } // D = logq
size_t n_bar() const { return m_n_bar; }
size_t len_a_bytes() const { return m_len_a / 8; } // len of seed_a in bytes
size_t len_se_bytes() const { return m_len_se / 8; }
size_t len_sec_bytes() const { return m_nist_strength / 8; }
size_t len_salt_bytes() const { return m_len_salt / 8; }
size_t len_ct_bytes() const {
return (m_d * m_n * m_n_bar + m_d * m_n_bar * m_n_bar + m_len_salt) / 8;
} // Ciphertext length in bytes
size_t len_public_key_bytes() const { return (m_len_a + (m_d * m_n * m_n_bar)) / 8; }
size_t len_private_key_bytes() const {
return (m_nist_strength + m_len_a + (m_d * m_n * m_n_bar) + (m_n_bar * m_n * 16) + m_nist_strength) / 8;
}
size_t len_packed_b_bytes() const { return (m_d * m_n * m_n_bar) / 8; }
size_t len_packed_c_bytes() const { return (m_d * m_n_bar * m_n_bar) / 8; }
FrodoDomainSeparator encapsulation_domain_separator() const { return FrodoDomainSeparator({0x96}); }
FrodoDomainSeparator keygen_domain_separator() const { return FrodoDomainSeparator({0x5F}); }
// TODO: those aren't actually const. We worked around some constness
// issues when playing with the XOFs that are residing in this class.
XOF& SHAKE_XOF() const;
private:
FrodoKEMMode m_mode;
size_t m_nist_strength;
size_t m_len_salt;
size_t m_len_se;
size_t m_len_a;
size_t m_b;
size_t m_n;
size_t m_n_bar;
size_t m_d;
std::vector<uint16_t> m_cdf_table; // Distribution table T_chi
mutable std::unique_ptr<XOF> m_shake_xof;
std::string m_shake;
};
} // namespace Botan
#endif