Botan::LMOTS_Signature Class Reference

Representation of a LM-OTS signature. More...

#include <lm_ots.h>

Public Member Functions
LMOTS_Algorithm_Type	algorithm_type () const
	Returns the LM-OTS algorithm type.
std::span< const uint8_t >	C () const
	The n-byte randomizer of the signature.
StrongSpan< const LMOTS_Node >	y (uint16_t chain_idx) const
	Returns the part of the signature for chain_idx.

Static Public Member Functions
static LMOTS_Signature	from_bytes_or_throw (BufferSlicer &slicer)
	Parse a LM-OTS signature.
static size_t	size (const LMOTS_Params &params)
	The expected size of the signature.

Detailed Description

Representation of a LM-OTS signature.

Definition at line 178 of file lm_ots.h.

Member Function Documentation

algorithm_type()

LMOTS_Algorithm_Type Botan::LMOTS_Signature::algorithm_type ( ) const

inline

Returns the LM-OTS algorithm type.

Definition at line 192 of file lm_ots.h.

{ return m_algorithm_type; }

Referenced by from_bytes_or_throw(), Botan::LMS_Signature::from_bytes_or_throw(), Botan::lmots_compute_pubkey_from_sig(), and Botan::LMS_PublicKey::verify_signature().

C()

std::span< const uint8_t > Botan::LMOTS_Signature::C ( ) const

inline

The n-byte randomizer of the signature.

Definition at line 197 of file lm_ots.h.

{ return m_C; }

Referenced by from_bytes_or_throw(), and Botan::lmots_compute_pubkey_from_sig().

from_bytes_or_throw()

LMOTS_Signature Botan::LMOTS_Signature::from_bytes_or_throw ( BufferSlicer & slicer )

static

Parse a LM-OTS signature.

Parameters

slicer

The private key bytes to parse.

Returns

The LM-OTS signature.

Exceptions

Decoding_Error

If parsing the signature fails.

Definition at line 235 of file lm_ots.cpp.

                                                                         {
   size_t total_remaining_bytes = slicer.remaining();
   // Alg. 6a. 1. (last 4 bytes) / Alg. 4b. 1.
   if(total_remaining_bytes < sizeof(LMOTS_Algorithm_Type)) {
      throw Decoding_Error("Too few signature bytes while parsing LMOTS signature.");
   }
   // Alg. 6a. 2.b. / Alg. 4b. 2.a.
   auto algorithm_type = load_be<LMOTS_Algorithm_Type>(slicer.take<sizeof(LMOTS_Algorithm_Type)>());
 
   // Alg. 6a. 2.d. / Alg. 4b. 2.c.
   LMOTS_Params params = LMOTS_Params::create_or_throw(algorithm_type);
 
   if(total_remaining_bytes < size(params)) {
      throw Decoding_Error("Too few signature bytes while parsing LMOTS signature.");
   }
 
   // Alg. 4b. 2.d.
   auto C = slicer.copy_as_vector(params.n());
   // Alg. 4b. 2.e.
   auto m_y_buffer = slicer.copy_as_vector(params.p() * params.n());
 
   return LMOTS_Signature(algorithm_type, std::move(C), std::move(m_y_buffer));
}

References algorithm_type(), C(), Botan::BufferSlicer::copy_as_vector(), Botan::LMOTS_Params::create_or_throw(), Botan::load_be(), Botan::LMOTS_Params::n(), Botan::LMOTS_Params::p(), Botan::BufferSlicer::remaining(), size(), and Botan::BufferSlicer::take().

Referenced by Botan::LMS_Signature::from_bytes_or_throw().

size()

static size_t Botan::LMOTS_Signature::size ( const LMOTS_Params & params )

inlinestatic

The expected size of the signature.

Definition at line 207 of file lm_ots.h.

{ return 4 + params.n() * (params.p() + 1); }

References Botan::LMOTS_Params::n(), and Botan::LMOTS_Params::p().

Referenced by from_bytes_or_throw(), Botan::LMOTS_Private_Key::sign(), Botan::LMS_PrivateKey::sign_and_get_pk(), and Botan::LMS_Signature::size().

y()

StrongSpan< const LMOTS_Node > Botan::LMOTS_Signature::y ( uint16_t chain_idx ) const

inline

Returns the part of the signature for chain_idx.

Definition at line 202 of file lm_ots.h.

{ return m_y.at(chain_idx); }

Referenced by Botan::lmots_compute_pubkey_from_sig().

---

The documentation for this class was generated from the following files:

• src/lib/pubkey/hss_lms/lm_ots.h
• src/lib/pubkey/hss_lms/lm_ots.cpp