Helper class used to derive secret values based in the pseudorandom key generation described in RFC 8554 Appendix A. More...

#include <hss_lms_utils.h>

Public Member Functions
template<concepts::resizable_byte_buffer T = secure_vector<uint8_t>>
T	gen (HashFunction &hash, std::span< const uint8_t > seed) const
	Create a hash value using the preconfigured prefix and a `seed`.
void	gen (std::span< uint8_t > out, HashFunction &hash, std::span< const uint8_t > seed) const
	Create a hash value using the preconfigured prefix and a `seed`.
PseudorandomKeyGeneration &	operator= (const PseudorandomKeyGeneration &)=delete
PseudorandomKeyGeneration &	operator= (PseudorandomKeyGeneration &&)=delete
	PseudorandomKeyGeneration (const PseudorandomKeyGeneration &)=delete
	PseudorandomKeyGeneration (PseudorandomKeyGeneration &&)=delete
	PseudorandomKeyGeneration (std::span< const uint8_t > identifier)
	Create a PseudorandomKeyGeneration instance for a fixed `identifier`.
void	set_i (uint16_t i)
	Specify the value for the u16str(i) hash input field.
void	set_j (uint8_t j)
	Specify the value for the u8str(j) hash input field.
void	set_q (uint32_t q)
	Specify the value for the u32str(q) hash input field.
	~PseudorandomKeyGeneration ()=default

Detailed Description

Helper class used to derive secret values based in the pseudorandom key generation described in RFC 8554 Appendix A.

This generation computes the following:

Result = Hash( identifier || u32str(q) || u16str(i) || u8str(j) || SEED )

This Key Generation procedure is also used for the seed derivation function of SECRET_METHOD 2 defined in https://github.com/cisco/hash-sigs,

Definition at line 28 of file hss_lms_utils.h.

Constructor & Destructor Documentation

◆ PseudorandomKeyGeneration() [1/3]

Botan::PseudorandomKeyGeneration::PseudorandomKeyGeneration ( std::span< const uint8_t > identifier )

explicit

Create a PseudorandomKeyGeneration instance for a fixed identifier.

Definition at line 16 of file hss_lms_utils.cpp.

                                                                                      :
      m_input_buffer(identifier.size() + 7),
      m_q(std::span(m_input_buffer).last<7>().first<4>()),
      m_i(std::span(m_input_buffer).last<3>().first<2>()),
      m_j(std::span(m_input_buffer).last<1>()) {
   copy_mem(std::span(m_input_buffer).first(identifier.size()), identifier);
}

References Botan::copy_mem().

Referenced by operator=(), operator=(), PseudorandomKeyGeneration(), and PseudorandomKeyGeneration().

◆ PseudorandomKeyGeneration() [2/3]

Botan::PseudorandomKeyGeneration::PseudorandomKeyGeneration ( const PseudorandomKeyGeneration & )

delete

References PseudorandomKeyGeneration().

◆ PseudorandomKeyGeneration() [3/3]

Botan::PseudorandomKeyGeneration::PseudorandomKeyGeneration ( PseudorandomKeyGeneration && )

delete

References PseudorandomKeyGeneration().

◆ ~PseudorandomKeyGeneration()

Botan::PseudorandomKeyGeneration::~PseudorandomKeyGeneration ( )

default

Member Function Documentation

◆ gen() [1/2]

template<concepts::resizable_byte_buffer T = secure_vector<uint8_t>>

T Botan::PseudorandomKeyGeneration::gen	(	HashFunction &	hash,
		std::span< const uint8_t >	seed ) const

inline

Create a hash value using the preconfigured prefix and a seed.

Definition at line 62 of file hss_lms_utils.h.

                                                                   {
         T output(hash.output_length());
         gen(output, hash, seed);
         return output;
      }

References gen(), and Botan::Buffered_Computation::output_length().

Referenced by gen(), and Botan::LMOTS_Private_Key::LMOTS_Private_Key().

◆ gen() [2/2]

void Botan::PseudorandomKeyGeneration::gen	(	std::span< uint8_t >	out,
		HashFunction &	hash,
		std::span< const uint8_t >	seed ) const

Create a hash value using the preconfigured prefix and a seed.

Definition at line 24 of file hss_lms_utils.cpp.

                                                                                                               {
   hash.update(m_input_buffer);
   hash.update(seed);
   hash.final(out);
}

References Botan::Buffered_Computation::final(), and Botan::Buffered_Computation::update().