Botan::XMSS_Common_Ops Class Reference

#include <xmss_common_ops.h>

Inheritance diagram for Botan::XMSS_Common_Ops:

Public Member Functions
	XMSS_Common_Ops (XMSS_Parameters::xmss_algorithm_t oid)

Protected Member Functions
void	create_l_tree (secure_vector< uint8_t > &result, wots_keysig_t pk, XMSS_Address &adrs, const secure_vector< uint8_t > &seed, XMSS_Hash &hash)
void	create_l_tree (secure_vector< uint8_t > &result, wots_keysig_t pk, XMSS_Address &adrs, const secure_vector< uint8_t > &seed)
void	randomize_tree_hash (secure_vector< uint8_t > &result, const secure_vector< uint8_t > &left, const secure_vector< uint8_t > &right, XMSS_Address &adrs, const secure_vector< uint8_t > &seed, XMSS_Hash &hash)
void	randomize_tree_hash (secure_vector< uint8_t > &result, const secure_vector< uint8_t > &left, const secure_vector< uint8_t > &right, XMSS_Address &adrs, const secure_vector< uint8_t > &seed)

Protected Attributes
XMSS_Hash	m_hash
XMSS_Parameters	m_xmss_params

Detailed Description

Operations shared by XMSS signature generation and verification operations.

Definition at line 26 of file xmss_common_ops.h.

Constructor & Destructor Documentation

Botan::XMSS_Common_Ops::XMSS_Common_Ops ( XMSS_Parameters::xmss_algorithm_t  oid )

inline

Definition at line 29 of file xmss_common_ops.h.

         : m_xmss_params(oid), m_hash(m_xmss_params.hash_function_name()) {}

Member Function Documentation

void Botan::XMSS_Common_Ops::create_l_tree ( secure_vector< uint8_t > &  result, wots_keysig_t  pk, XMSS_Address &  adrs, const secure_vector< uint8_t > &  seed, XMSS_Hash &  hash  )

protected

Algorithm 8: "ltree" Create an L-tree used to compute the leaves of the binary hash tree. Takes a WOTS+ public key and compresses it to a single n-byte value.

This overload is used in multithreaded scenarios, where it is required to provide seperate instances of XMSS_Hash to each thread.

Parameters

[out]	result	Public key compressed to a single n-byte value pk[0].
[in]	pk	Winternitz One Time Signatures+ public key.
[in]	adrs	Address encoding the address of the L-Tree
[in]	seed	The seed generated during the public key generation.
[in]	hash	Instance of XMSS_Hash, that may only be used by the thead executing create_l_tree.

Definition at line 46 of file xmss_common_ops.cpp.

References Botan::XMSS_Address::get_tree_height(), Botan::XMSS_Parameters::len(), m_xmss_params, randomize_tree_hash(), Botan::XMSS_Address::set_tree_height(), and Botan::XMSS_Address::set_tree_index().

Referenced by create_l_tree().

   {
   size_t l = m_xmss_params.len();
   adrs.set_tree_height(0);

   while(l > 1)
      {
      for(size_t i = 0; i < l >> 1; i++)
         {
         adrs.set_tree_index(static_cast<uint32_t>(i));
         randomize_tree_hash(pk[i], pk[2 * i], pk[2 * i + 1], adrs, seed, hash);
         }
      if(l & 0x01)
         {
         pk[l >> 1] = pk[l - 1];
         }
      l = (l >> 1) + (l & 0x01);
      adrs.set_tree_height(adrs.get_tree_height() + 1);
      }
   result = pk[0];
   }

void Botan::XMSS_Common_Ops::create_l_tree ( secure_vector< uint8_t > &  result, wots_keysig_t  pk, XMSS_Address &  adrs, const secure_vector< uint8_t > &  seed  )

inlineprotected

Algorithm 8: "ltree" Create an L-tree used to compute the leaves of the binary hash tree. Takes a WOTS+ public key and compresses it to a single n-byte value.

Parameters

[out]	result	Public key compressed to a single n-byte value pk[0].
[in]	pk	Winternitz One Time Signatures+ public key.
[in]	adrs	Address encoding the address of the L-Tree
[in]	seed	The seed generated during the public key generation.

Definition at line 112 of file xmss_common_ops.h.

References create_l_tree(), and m_hash.

         {
         create_l_tree(result, pk, adrs, seed, m_hash);
         }

void Botan::XMSS_Common_Ops::randomize_tree_hash ( secure_vector< uint8_t > &  result, const secure_vector< uint8_t > &  left, const secure_vector< uint8_t > &  right, XMSS_Address &  adrs, const secure_vector< uint8_t > &  seed, XMSS_Hash &  hash  )

protected

Algorithm 7: "RAND_HASH"

Generates a randomized hash.

This overload is used in multithreaded scenarios, where it is required to provide seperate instances of XMSS_Hash to each thread.

Parameters

[out]	result	The resulting randomized hash.
[in]	left	Left half of the hash function input.
[in]	right	Right half of the hash function input.
[in]	adrs	Adress of the hash function call.
[in]	seed	The seed for G.
[in]	hash	Instance of XMSS_Hash, that may only by the thead executing generate_public_key.

Definition at line 14 of file xmss_common_ops.cpp.

References BOTAN_ASSERT, Botan::XMSS_Address::bytes(), Botan::XMSS_Parameters::element_size(), Botan::XMSS_Hash::h(), Botan::XMSS_Address::Key_Mode, m_xmss_params, Botan::XMSS_Address::Mask_LSB_Mode, Botan::XMSS_Address::Mask_MSB_Mode, Botan::XMSS_Hash::prf(), and Botan::XMSS_Address::set_key_mask_mode().

Referenced by create_l_tree(), randomize_tree_hash(), and Botan::XMSS_PrivateKey::tree_hash().

   {
   adrs.set_key_mask_mode(XMSS_Address::Key_Mask::Key_Mode);
   secure_vector<uint8_t> key { hash.prf(seed, adrs.bytes()) };

   adrs.set_key_mask_mode(XMSS_Address::Key_Mask::Mask_MSB_Mode);
   secure_vector<uint8_t> bitmask_l { hash.prf(seed, adrs.bytes()) };

   adrs.set_key_mask_mode(XMSS_Address::Key_Mask::Mask_LSB_Mode);
   secure_vector<uint8_t> bitmask_r { hash.prf(seed, adrs.bytes()) };

   BOTAN_ASSERT(bitmask_l.size() == left.size() &&
                bitmask_r.size() == right.size(),
                "Bitmask size doesn't match node size.");

   secure_vector<uint8_t> concat_xor(m_xmss_params.element_size() * 2);
   for(size_t i = 0; i < left.size(); i++)
      {
      concat_xor[i] = left[i] ^ bitmask_l[i];
      concat_xor[i + left.size()] = right[i] ^ bitmask_r[i];
      }

   hash.h(result, key, concat_xor);
   }

void Botan::XMSS_Common_Ops::randomize_tree_hash ( secure_vector< uint8_t > &  result, const secure_vector< uint8_t > &  left, const secure_vector< uint8_t > &  right, XMSS_Address &  adrs, const secure_vector< uint8_t > &  seed  )

inlineprotected

Algorithm 7: "RAND_HASH"

Generates a randomized hash.

Parameters

[out]	result	The resulting randomized hash.
[in]	left	Left half of the hash function input.
[in]	right	Right half of the hash function input.
[in]	adrs	Adress of the hash function call.
[in]	seed	The seed for G.

Definition at line 69 of file xmss_common_ops.h.

References m_hash, and randomize_tree_hash().

         {
         randomize_tree_hash(result, left, right, adrs, seed, m_hash);
         }

Member Data Documentation

XMSS_Hash Botan::XMSS_Common_Ops::m_hash

protected

Definition at line 122 of file xmss_common_ops.h.

Referenced by create_l_tree(), randomize_tree_hash(), Botan::XMSS_Signature_Operation::sign(), Botan::XMSS_PrivateKey::tree_hash(), and Botan::XMSS_Signature_Operation::update().

XMSS_Parameters Botan::XMSS_Common_Ops::m_xmss_params

protected

Definition at line 121 of file xmss_common_ops.h.

Referenced by create_l_tree(), randomize_tree_hash(), and Botan::XMSS_Signature_Operation::signature_length().

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

• src/lib/pubkey/xmss/xmss_common_ops.h
• src/lib/pubkey/xmss/xmss_common_ops.cpp