Botan::XMSS_Hash Class Reference

#include <xmss_hash.h>

Public Member Functions
void	f (secure_vector< uint8_t > &result, const secure_vector< uint8_t > &key, const secure_vector< uint8_t > &data)
void	h (secure_vector< uint8_t > &result, const secure_vector< uint8_t > &key, const secure_vector< uint8_t > &data)
secure_vector< uint8_t >	h_msg (const secure_vector< uint8_t > &randomness, const secure_vector< uint8_t > &root, const secure_vector< uint8_t > &index_bytes, const secure_vector< uint8_t > &data)
secure_vector< uint8_t >	h_msg_final ()
void	h_msg_init (const secure_vector< uint8_t > &randomness, const secure_vector< uint8_t > &root, const secure_vector< uint8_t > &index_bytes)
void	h_msg_update (const uint8_t data[], size_t size)
size_t	output_length () const
secure_vector< uint8_t >	prf (const secure_vector< uint8_t > &key, const secure_vector< uint8_t > &data)
void	prf (secure_vector< uint8_t > &result, const secure_vector< uint8_t > &key, const secure_vector< uint8_t > &data)
	XMSS_Hash (const std::string &h_func_name)
	XMSS_Hash (const XMSS_Hash &hash)

Detailed Description

A collection of pseudorandom hash functions required for XMSS and WOTS computations.

Definition at line 21 of file xmss_hash.h.

Constructor & Destructor Documentation

XMSS_Hash() [1/2]

Botan::XMSS_Hash::XMSS_Hash

(

const std::string &

h_func_name

)

Definition at line 20 of file xmss_hash.cpp.

                                                 :
   m_hash(HashFunction::create(h_func_name)),
   m_hash_func_name(h_func_name)
   {
   if(!m_hash)
      throw Lookup_Error("XMSS cannot use hash " + h_func_name +
                         " because it is unavailable");
 
   m_output_length = m_hash->output_length();
   BOTAN_ASSERT(m_output_length > 0, "Hash output length of zero is invalid.");
 
   m_zero_padding.resize(m_output_length - 1);
   m_msg_hash.reset(m_hash->clone());
   }

XMSS_Hash() [2/2]

Botan::XMSS_Hash::XMSS_Hash

(

const XMSS_Hash &

hash

)

Definition at line 15 of file xmss_hash.cpp.

   : XMSS_Hash(hash.m_hash_func_name)
   {
   }

Member Function Documentation

f()

void Botan::XMSS_Hash::f ( secure_vector< uint8_t > &  result, const secure_vector< uint8_t > &  key, const secure_vector< uint8_t > &  data  )

inline

F is a keyed cryptographic hash function used by the WOTS+ algorithm.

Parameters

[out]	result	The hash calculated using key and data.
[in]	key	key of length n bytes.
[in]	data	string of arbitrary length.

Definition at line 71 of file xmss_hash.h.

         {
         m_hash->update(m_zero_padding);
         m_hash->update(m_id_f);
         m_hash->update(key);
         m_hash->update(data);
         m_hash->final(result);
         }

h()

void Botan::XMSS_Hash::h	(	secure_vector< uint8_t > &	result,
		const secure_vector< uint8_t > &	key,
		const secure_vector< uint8_t > &	data
	)

Cryptographic hash function h accepting n byte keys and 2n byte strings of data.

Parameters

[out]	result	The hash calculated using key and data.
[in]	key	key of length n bytes.
[in]	data	string of 2n bytes length.

Definition at line 36 of file xmss_hash.cpp.

   {
   m_hash->update(m_zero_padding);
   m_hash->update(m_id_h);
   m_hash->update(key);
   m_hash->update(data);
   m_hash->final(result);
   }

h_msg()

secure_vector< uint8_t > Botan::XMSS_Hash::h_msg	(	const secure_vector< uint8_t > &	randomness,
		const secure_vector< uint8_t > &	root,
		const secure_vector< uint8_t > &	index_bytes,
		const secure_vector< uint8_t > &	data
	)

Cryptographic hash function h accepting 3n byte keys and data strings of arbitrary length.

Parameters

randomness	n-byte value.
root	n-byte root node.
index_bytes	Index value padded with leading zeros.
data	string of arbitrary length.

Returns

hash value of n-bytes length.

Definition at line 70 of file xmss_hash.cpp.

   {
   h_msg_init(randomness, root, index_bytes);
   m_msg_hash->update(data);
   return m_msg_hash->final();
   }

References h_msg_init().

h_msg_final()

secure_vector< uint8_t > Botan::XMSS_Hash::h_msg_final

(

)

Finalizes buffered h_msg computation and retrieves the result.

Returns

Hash calculated using the prefix set by h_msg_init() and message blocks provided through calls to h_msg_update().

Definition at line 64 of file xmss_hash.cpp.

   {
   return m_msg_hash->final();
   }

Referenced by Botan::XMSS_Signature_Operation::sign().

h_msg_init()

void Botan::XMSS_Hash::h_msg_init	(	const secure_vector< uint8_t > &	randomness,
		const secure_vector< uint8_t > &	root,
		const secure_vector< uint8_t > &	index_bytes
	)

Initializes buffered h_msg computation with prefix data.

Parameters

randomness	random n-byte value.
root	n-byte root node.
index_bytes	Index value padded with leading zeros.

Definition at line 47 of file xmss_hash.cpp.

   {
   m_msg_hash->clear();
   m_msg_hash->update(m_zero_padding);
   m_msg_hash->update(m_id_hmsg);
   m_msg_hash->update(randomness);
   m_msg_hash->update(root);
   m_msg_hash->update(index_bytes);
   }

Referenced by h_msg().

h_msg_update()

void Botan::XMSS_Hash::h_msg_update	(	const uint8_t	data[],
		size_t	size
	)

Adds a message block to buffered h_msg computation.

Parameters

data	A message block
size	Length of the message block in bytes.

Definition at line 59 of file xmss_hash.cpp.

   {
   m_msg_hash->update(data, size);
   }

Referenced by Botan::XMSS_Signature_Operation::update().

output_length()

size_t Botan::XMSS_Hash::output_length ( ) const

inline

Definition at line 137 of file xmss_hash.h.

{ return m_output_length; }

prf() [1/2]

secure_vector< uint8_t > Botan::XMSS_Hash::prf ( const secure_vector< uint8_t > &  key, const secure_vector< uint8_t > &  data  )

inline

Pseudoranom function creating a hash out of a key and data using a cryptographic hash function.

Parameters

[in]	key	An n-byte key value.
[in]	data	A 32-byte XMSS_Address data value

Returns

result The hash calculated using key and data.

Definition at line 54 of file xmss_hash.h.

         {
         m_hash->update(m_zero_padding);
         m_hash->update(m_id_prf);
         m_hash->update(key);
         m_hash->update(data);
         return m_hash->final();
         }

prf() [2/2]

void Botan::XMSS_Hash::prf ( secure_vector< uint8_t > &  result, const secure_vector< uint8_t > &  key, const secure_vector< uint8_t > &  data  )

inline

Pseudoranom function creating a hash out of a key and data using a cryptographic hash function.

Parameters

[out]	result	The hash calculated using key and data.
[in]	key	An n-byte key value.
[in]	data	A 32-byte XMSS_Address data value

Definition at line 35 of file xmss_hash.h.

         {
         m_hash->update(m_zero_padding);
         m_hash->update(m_id_prf);
         m_hash->update(key);
         m_hash->update(data);
         m_hash->final(result);
         }

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

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