Botan::XMSS_WOTS_Parameters Class Reference

#include <xmss_parameters.h>

Public Types
enum	ots_algorithm_t : uint32_t {   WOTSP_SHA2_256 = 0x00000001 , WOTSP_SHA2_512 = 0x00000002 , WOTSP_SHAKE_256 = 0x00000003 , WOTSP_SHAKE_512 = 0x00000004 ,   WOTSP_SHA2_192 = 0x00000005 , WOTSP_SHAKE_256_256 = 0x00000006 , WOTSP_SHAKE_256_192 = 0x00000007 }

Public Member Functions
void	append_checksum (secure_vector< uint8_t > &data) const
secure_vector< uint8_t >	base_w (const secure_vector< uint8_t > &msg, size_t out_size) const
secure_vector< uint8_t >	base_w (size_t value) const
size_t	element_size () const
size_t	estimated_strength () const
size_t	len () const
size_t	len_1 () const
size_t	len_2 () const
size_t	lg_w () const
const std::string &	name () const
ots_algorithm_t	oid () const
bool	operator== (const XMSS_WOTS_Parameters &p) const
size_t	wots_parameter () const
BOTAN_FUTURE_EXPLICIT	XMSS_WOTS_Parameters (ots_algorithm_t ots_spec)
	XMSS_WOTS_Parameters (std::string_view algo_name)

Static Public Member Functions
static ots_algorithm_t	xmss_wots_id_from_string (std::string_view param_set)

Detailed Description

Descibes a signature method for XMSS Winternitz One Time Signatures, as defined in: [1] XMSS: Extended Hash-Based Signatures, Request for Comments: 8391 Release: May 2018. https://datatracker.ietf.org/doc/rfc8391/ [2] Recommendation for Stateful Hash-Based Signature Schemes NIST Special Publication 800-208 Release: October 2020. https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-208.pdf

Definition at line 31 of file xmss_parameters.h.

Member Enumeration Documentation

ots_algorithm_t

enum Botan::XMSS_WOTS_Parameters::ots_algorithm_t : uint32_t

Enumerator
WOTSP_SHA2_256
WOTSP_SHA2_512
WOTSP_SHAKE_256
WOTSP_SHAKE_512
WOTSP_SHA2_192
WOTSP_SHAKE_256_256
WOTSP_SHAKE_256_192

Definition at line 33 of file xmss_parameters.h.

                           : uint32_t /* NOLINT(*-enum-size) */ {
         // from RFC 8391
         WOTSP_SHA2_256 = 0x00000001,
 
         // from RFC 8391 but not approved by NIST SP.800-208
         // (see footnote on page 16)
         WOTSP_SHA2_512 = 0x00000002,
         WOTSP_SHAKE_256 = 0x00000003,
         WOTSP_SHAKE_512 = 0x00000004,
 
         // from NIST SP.800-208
         WOTSP_SHA2_192 = 0x00000005,
         WOTSP_SHAKE_256_256 = 0x00000006,
         WOTSP_SHAKE_256_192 = 0x00000007,
      };

Constructor & Destructor Documentation

XMSS_WOTS_Parameters() [1/2]

Botan::XMSS_WOTS_Parameters::XMSS_WOTS_Parameters ( std::string_view algo_name )

explicit

Definition at line 51 of file xmss_wots_parameters.cpp.

                                                                   :
      XMSS_WOTS_Parameters(xmss_wots_id_from_string(param_set)) {}

References xmss_wots_id_from_string(), and XMSS_WOTS_Parameters().

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

XMSS_WOTS_Parameters() [2/2]

Botan::XMSS_WOTS_Parameters::XMSS_WOTS_Parameters

(

ots_algorithm_t

ots_spec

)

Definition at line 54 of file xmss_wots_parameters.cpp.

                                                              : m_oid(oid) {
   switch(oid) {
      case WOTSP_SHA2_256:
         m_element_size = 32;
         m_w = 16;
         m_len = 67;
         m_name = "WOTSP-SHA2_256";
         m_hash_name = "SHA-256";
         m_strength = 256;
         break;
      case WOTSP_SHA2_512:
         m_element_size = 64;
         m_w = 16;
         m_len = 131;
         m_name = "WOTSP-SHA2_512";
         m_hash_name = "SHA-512";
         m_strength = 512;
         break;
      case WOTSP_SHAKE_256:
         m_element_size = 32;
         m_w = 16;
         m_len = 67;
         m_name = "WOTSP-SHAKE_256";
         m_hash_name = "SHAKE-128(256)";
         m_strength = 256;
         break;
      case WOTSP_SHAKE_512:
         m_element_size = 64;
         m_w = 16;
         m_len = 131;
         m_name = "WOTSP-SHAKE_512";
         m_hash_name = "SHAKE-256(512)";
         m_strength = 512;
         break;
      case WOTSP_SHA2_192:
         m_element_size = 24;
         m_w = 16;
         m_len = 51;
         m_name = "WOTSP-SHA2_192";
         m_hash_name = "Truncated(SHA-256,192)";
         m_strength = 192;
         break;
      case WOTSP_SHAKE_256_256:
         m_element_size = 32;
         m_w = 16;
         m_len = 67;
         m_name = "WOTSP-SHAKE_256_256";
         m_hash_name = "SHAKE-256(256)";
         m_strength = 256;
         break;
      case WOTSP_SHAKE_256_192:
         m_element_size = 24;
         m_w = 16;
         m_len = 51;
         m_name = "WOTSP-SHAKE_256_192";
         m_hash_name = "SHAKE-256(192)";
         m_strength = 192;
         break;
      default:
         throw Not_Implemented("Algorithm id does not match any known XMSS WOTS algorithm id.");
   }
 
   m_lg_w = (m_w == 16) ? 4 : 2;
   m_len_1 = static_cast<size_t>(std::ceil((8 * element_size()) / m_lg_w));
   m_len_2 = static_cast<size_t>(floor(log2(m_len_1 * (wots_parameter() - 1)) / m_lg_w) + 1);
   BOTAN_ASSERT(m_len == m_len_1 + m_len_2,
                "Invalid XMSS WOTS parameter "
                "\"len\" detected.");
}

References BOTAN_ASSERT, element_size(), oid(), wots_parameter(), WOTSP_SHA2_192, WOTSP_SHA2_256, WOTSP_SHA2_512, WOTSP_SHAKE_256, WOTSP_SHAKE_256_192, WOTSP_SHAKE_256_256, and WOTSP_SHAKE_512.

Member Function Documentation

append_checksum()

void Botan::XMSS_WOTS_Parameters::append_checksum

(

secure_vector< uint8_t > &

data

)

const

Definition at line 152 of file xmss_wots_parameters.cpp.

                                                                             {
   size_t csum = 0;
 
   for(uint8_t b : data) {
      csum += wots_parameter() - 1 - b;
   }
 
   secure_vector<uint8_t> csum_bytes = base_w(csum);
   std::move(csum_bytes.begin(), csum_bytes.end(), std::back_inserter(data));
}

References base_w(), and wots_parameter().

base_w() [1/2]

secure_vector< uint8_t > Botan::XMSS_WOTS_Parameters::base_w	(	const secure_vector< uint8_t > &	msg,
		size_t	out_size ) const

Algorithm 1: convert input string to base.

Parameters

msg	Input string (referred to as X in [1]).
out_size	size of message in base w.

Returns

Input string converted to the given base.

Definition at line 124 of file xmss_wots_parameters.cpp.

                                                                                                            {
   secure_vector<uint8_t> result;
   result.reserve(out_size);
 
   size_t in = 0;
   size_t total = 0;
   size_t bits = 0;
 
   for(size_t i = 0; i < out_size; i++) {
      if(bits == 0) {
         total = msg[in];
         in++;
         bits += 8;
      }
      bits -= m_lg_w;
      result.push_back(static_cast<uint8_t>((total >> bits) & (m_w - 1)));
   }
   return result;
}

Referenced by append_checksum(), and base_w().

base_w() [2/2]

secure_vector< uint8_t > Botan::XMSS_WOTS_Parameters::base_w

(

size_t

value

)

const

Definition at line 144 of file xmss_wots_parameters.cpp.

                                                                      {
   value <<= (8 - ((m_len_2 * m_lg_w) % 8));
   size_t len_2_bytes = static_cast<size_t>(std::ceil(static_cast<float>(m_len_2 * m_lg_w) / 8.0));
   secure_vector<uint8_t> result;
   xmss_concat(result, value, len_2_bytes);
   return base_w(result, m_len_2);
}

References base_w(), and Botan::xmss_concat().

element_size()

size_t Botan::XMSS_WOTS_Parameters::element_size ( ) const

inline

Retrieves the uniform length of a message, and the size of each node. This correlates to XMSS parameter "n" defined in [1].

Returns

element length in bytes.

Definition at line 81 of file xmss_parameters.h.

{ return m_element_size; }

Referenced by XMSS_WOTS_Parameters().

estimated_strength()

size_t Botan::XMSS_WOTS_Parameters::estimated_strength ( ) const

inline

Definition at line 101 of file xmss_parameters.h.

{ return m_strength; }

len()

size_t Botan::XMSS_WOTS_Parameters::len ( ) const

inline

Definition at line 91 of file xmss_parameters.h.

{ return m_len; }

len_1()

size_t Botan::XMSS_WOTS_Parameters::len_1 ( ) const

inline

Definition at line 93 of file xmss_parameters.h.

{ return m_len_1; }

len_2()

size_t Botan::XMSS_WOTS_Parameters::len_2 ( ) const

inline

Definition at line 95 of file xmss_parameters.h.

{ return m_len_2; }

lg_w()

size_t Botan::XMSS_WOTS_Parameters::lg_w ( ) const

inline

Definition at line 97 of file xmss_parameters.h.

{ return m_lg_w; }

name()

const std::string & Botan::XMSS_WOTS_Parameters::name ( ) const

inline

Returns

XMSS WOTS registry name for the chosen parameter set.

Definition at line 72 of file xmss_parameters.h.

{ return m_name; }

oid()

ots_algorithm_t Botan::XMSS_WOTS_Parameters::oid ( ) const

inline

Definition at line 99 of file xmss_parameters.h.

{ return m_oid; }

Referenced by XMSS_WOTS_Parameters().

operator==()

bool Botan::XMSS_WOTS_Parameters::operator== ( const XMSS_WOTS_Parameters & p ) const

inline

Definition at line 103 of file xmss_parameters.h.

{ return m_oid == p.m_oid; }

References XMSS_WOTS_Parameters().

wots_parameter()

size_t Botan::XMSS_WOTS_Parameters::wots_parameter ( ) const

inline

The Winternitz parameter.

Returns

numeric base used for internal representation of data.

Definition at line 89 of file xmss_parameters.h.

{ return m_w; }

Referenced by append_checksum(), and XMSS_WOTS_Parameters().

xmss_wots_id_from_string()

XMSS_WOTS_Parameters::ots_algorithm_t Botan::XMSS_WOTS_Parameters::xmss_wots_id_from_string ( std::string_view param_set )

static

Definition at line 25 of file xmss_wots_parameters.cpp.

                                                                                                           {
   if(param_set == "WOTSP-SHA2_256") {
      return WOTSP_SHA2_256;
   }
   if(param_set == "WOTSP-SHA2_512") {
      return WOTSP_SHA2_512;
   }
   if(param_set == "WOTSP-SHAKE_256") {
      return WOTSP_SHAKE_256;
   }
   if(param_set == "WOTSP-SHAKE_512") {
      return WOTSP_SHAKE_512;
   }
   if(param_set == "WOTSP-SHA2_192") {
      return WOTSP_SHA2_192;
   }
   if(param_set == "WOTSP-SHAKE_256_256") {
      return WOTSP_SHAKE_256_256;
   }
   if(param_set == "WOTSP-SHAKE_256_192") {
      return WOTSP_SHAKE_256_192;
   }
 
   throw Lookup_Error(fmt("Unknown XMSS-WOTS algorithm param '{}'", param_set));
}

References Botan::fmt(), WOTSP_SHA2_192, WOTSP_SHA2_256, WOTSP_SHA2_512, WOTSP_SHAKE_256, WOTSP_SHAKE_256_192, WOTSP_SHAKE_256_256, and WOTSP_SHAKE_512.

Referenced by XMSS_WOTS_Parameters().

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

• src/lib/pubkey/xmss/xmss_parameters.h
• src/lib/pubkey/xmss/xmss_wots_parameters.cpp