Botan::LMS_Signature Class Reference

Container for LMS Signature data. More...

#include <lms.h>

Public Member Functions
StrongSpan< const LMS_AuthenticationPath >	auth_path () const
	The authentication path bytes given by the signature.
const LMOTS_Signature &	lmots_sig () const
	The LMOTS signature object containing the parsed LMOTS signature bytes contained in the LMS signature.
LMS_Algorithm_Type	lms_type () const
	The LMS algorithm type given by the signature.
LMS_Tree_Node_Idx	q () const
	The index of the signing leaf given by the signature.

Static Public Member Functions
static LMS_Signature	from_bytes_or_throw (BufferSlicer &slicer)
	Parse the bytes of a lms signature into a LMS Signature object.
static size_t	size (const LMS_Params &lms_params, const LMOTS_Params &lmots_params)

Detailed Description

Container for LMS Signature data.

Contains a method for secure signature parsing.

Definition at line 293 of file lms.h.

Member Function Documentation

auth_path()

StrongSpan< const LMS_AuthenticationPath > Botan::LMS_Signature::auth_path ( ) const

inline

The authentication path bytes given by the signature.

('path[0] || ... || path[h-1]' in RFC 8554 5.4)

Definition at line 325 of file lms.h.

{ return m_auth_path; }

Referenced by from_bytes_or_throw().

from_bytes_or_throw()

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

static

Parse the bytes of a lms signature into a LMS Signature object.

Parameters

slicer

A BufferSlicer object at the position of the LMS_Signature to parse

Returns

LMS_Signature object

Exceptions

Decoding_Error

If parsing the signature fails.

Definition at line 317 of file lms.cpp.

                                                                     {
   size_t total_remaining_bytes = slicer.remaining();
   // Alg. 6a 1. (next 4 bytes are checked in LMOTS_Signature::from_bytes_or_throw)
   if(total_remaining_bytes < sizeof(LMS_Tree_Node_Idx)) {
      throw Decoding_Error("Too few signature bytes while parsing LMS signature.");
   }
   // Alg. 6a 2.a.
   auto q = load_be<LMS_Tree_Node_Idx>(slicer.take<sizeof(LMS_Tree_Node_Idx)>());
 
   // Alg. 6a 2.b.-e.
   auto lmots_sig = LMOTS_Signature::from_bytes_or_throw(slicer);
   LMOTS_Params lmots_params = LMOTS_Params::create_or_throw(lmots_sig.algorithm_type());
 
   if(slicer.remaining() < sizeof(LMS_Algorithm_Type)) {
      throw Decoding_Error("Too few signature bytes while parsing LMS signature.");
   }
   // Alg. 6a 2.f.
   auto lms_type = load_be<LMS_Algorithm_Type>(slicer.take<sizeof(LMS_Algorithm_Type)>());
   // Alg. 6a 2.h.
   LMS_Params lms_params = LMS_Params::create_or_throw(lms_type);
   // Alg. 6a 2.i. (signature is not exactly [...] bytes long)
   if(total_remaining_bytes < size(lms_params, lmots_params)) {
      throw Decoding_Error("Too few signature bytes while parsing LMS signature.");
   }
 
   // Alg. 6a 2.j.
   auto auth_path = slicer.copy<LMS_AuthenticationPath>(lms_params.m() * lms_params.h());
 
   return LMS_Signature(q, std::move(lmots_sig), lms_type, std::move(auth_path));
}

References Botan::LMOTS_Signature::algorithm_type(), auth_path(), Botan::BufferSlicer::copy(), Botan::LMOTS_Params::create_or_throw(), Botan::LMS_Params::create_or_throw(), Botan::LMOTS_Signature::from_bytes_or_throw(), Botan::LMS_Params::h(), lmots_sig(), lms_type(), Botan::load_be(), Botan::LMS_Params::m(), q(), Botan::BufferSlicer::remaining(), size(), and Botan::BufferSlicer::take().

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

lmots_sig()

const LMOTS_Signature & Botan::LMS_Signature::lmots_sig ( ) const

inline

The LMOTS signature object containing the parsed LMOTS signature bytes contained in the LMS signature.

Definition at line 313 of file lms.h.

{ return m_lmots_sig; }

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

lms_type()

LMS_Algorithm_Type Botan::LMS_Signature::lms_type ( ) const

inline

The LMS algorithm type given by the signature.

Definition at line 318 of file lms.h.

{ return m_lms_type; }

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

q()

LMS_Tree_Node_Idx Botan::LMS_Signature::q ( ) const

inline

The index of the signing leaf given by the signature.

Definition at line 307 of file lms.h.

{ return m_q; }

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

size()

size_t Botan::LMS_Signature::size ( const LMS_Params & lms_params, const LMOTS_Params & lmots_params )

static

Returns

size_t The expected size of the signature.

Definition at line 419 of file lms.cpp.

                                                                                         {
   return sizeof(uint32_t) + LMOTS_Signature::size(lmots_params) + sizeof(uint32_t) + lms_params.h() * lms_params.m();
}

References Botan::LMS_Params::h(), Botan::LMS_Params::m(), and Botan::LMOTS_Signature::size().

Referenced by from_bytes_or_throw(), Botan::HSS_LMS_PrivateKeyInternal::sign(), Botan::LMS_PrivateKey::sign_and_get_pk(), and Botan::HSS_Signature::size().

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

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