Botan::Lion Class Reference

#include <lion.h>

Inheritance diagram for Botan::Lion:

Public Member Functions
size_t	block_size () const
void	clear ()
BlockCipher *	clone () const
void	decrypt (byte block[]) const
void	decrypt (const byte in[], byte out[]) const
void	decrypt_n (const byte in[], byte out[], size_t blocks) const
void	encrypt (byte block[]) const
void	encrypt (const byte in[], byte out[]) const
void	encrypt_n (const byte in[], byte out[], size_t blocks) const
Key_Length_Specification	key_spec () const
	Lion (HashFunction *hash, StreamCipher *cipher, size_t block_size)
size_t	maximum_keylength () const
size_t	minimum_keylength () const
std::string	name () const
size_t	parallel_bytes () const
virtual size_t	parallelism () const
void	set_key (const byte key[], size_t length)
void	set_key (const SymmetricKey &key)
bool	valid_keylength (size_t length) const
	~Lion ()

Detailed Description

Lion is a block cipher construction designed by Ross Anderson and Eli Biham, described in "Two Practical and Provably Secure Block Ciphers: BEAR and LION". It has a variable block size and is designed to encrypt very large blocks (up to a megabyte)

http://www.cl.cam.ac.uk/~rja14/Papers/bear-lion.pdf

Definition at line 25 of file lion.h.

Constructor & Destructor Documentation

Lion()

Botan::Lion::Lion	(	HashFunction *	hash,
		StreamCipher *	cipher,
		size_t	block_size )

Parameters

hash	the hash to use internally
cipher	the stream cipher to use internally
block_size	the size of the block to use

Definition at line 111 of file lion.cpp.

                                                                       :
   BLOCK_SIZE(std::max<size_t>(2*hash_in->output_length() + 1, block_len)),
   LEFT_SIZE(hash_in->output_length()),
   RIGHT_SIZE(BLOCK_SIZE - LEFT_SIZE),
   hash(hash_in),
   cipher(sc_in)
   {
   if(2*LEFT_SIZE + 1 > BLOCK_SIZE)
      throw Invalid_Argument(name() + ": Chosen block size is too small");
 
   if(!cipher->valid_keylength(LEFT_SIZE))
      throw Invalid_Argument(name() + ": This stream/hash combo is invalid");
 
   key1.resize(LEFT_SIZE);
   key2.resize(LEFT_SIZE);
   }

References name().

Referenced by clone(), and Botan::Core_Engine::find_block_cipher().

~Lion()

Botan::Lion::~Lion ( )

inline

Definition at line 51 of file lion.h.

{ delete hash; delete cipher; }

Member Function Documentation

block_size()

size_t Botan::Lion::block_size ( ) const

inlinevirtual

Returns

block size of this algorithm

Implements Botan::BlockCipher.

Definition at line 31 of file lion.h.

{ return BLOCK_SIZE; }

clear()

void Botan::Lion::clear ( )

virtual

Zeroize internal state

Implements Botan::Algorithm.

Definition at line 100 of file lion.cpp.

   {
   hash->clear();
   cipher->clear();
   zeroise(key1);
   zeroise(key2);
   }

References Botan::zeroise().

clone()

BlockCipher * Botan::Lion::clone ( ) const

virtual

Get a new object representing the same algorithm as *this

Implements Botan::BlockCipher.

Definition at line 92 of file lion.cpp.

   {
   return new Lion(hash->clone(), cipher->clone(), BLOCK_SIZE);
   }

References Lion().

decrypt() [1/2]

void Botan::BlockCipher::decrypt ( byte block[] ) const

inlineinherited

Decrypt a block.

Parameters

block

the ciphertext block to be decrypted Must be of length block_size(). Will hold the result when the function has finished.

Definition at line 74 of file block_cipher.h.

{ decrypt_n(block, block, 1); }

References decrypt_n().

decrypt() [2/2]

void Botan::BlockCipher::decrypt ( const byte in[], byte out[] ) const

inlineinherited

Decrypt a block.

Parameters

in	The ciphertext block to be decypted as a byte array. Must be of length block_size().
out	The byte array designated to hold the decrypted block. Must be of length block_size().

Definition at line 57 of file block_cipher.h.

         { decrypt_n(in, out, 1); }

References decrypt_n().

decrypt_n()

void Botan::Lion::decrypt_n ( const byte in[], byte out[], size_t blocks ) const

virtual

Decrypt one or more blocks

Parameters

in	the input buffer (multiple of block_size())
out	the output buffer (same size as in)
blocks	the number of blocks to process

Implements Botan::BlockCipher.

Definition at line 44 of file lion.cpp.

   {
   SecureVector<byte> buffer_vec(LEFT_SIZE);
   byte* buffer = &buffer_vec[0];
 
   for(size_t i = 0; i != blocks; ++i)
      {
      xor_buf(buffer, in, &key2[0], LEFT_SIZE);
      cipher->set_key(buffer, LEFT_SIZE);
      cipher->cipher(in + LEFT_SIZE, out + LEFT_SIZE, RIGHT_SIZE);
 
      hash->update(out + LEFT_SIZE, RIGHT_SIZE);
      hash->final(buffer);
      xor_buf(out, in, buffer, LEFT_SIZE);
 
      xor_buf(buffer, out, &key1[0], LEFT_SIZE);
      cipher->set_key(buffer, LEFT_SIZE);
      cipher->cipher1(out + LEFT_SIZE, RIGHT_SIZE);
 
      in += BLOCK_SIZE;
      out += BLOCK_SIZE;
      }
   }

References Botan::xor_buf().

encrypt() [1/2]

void Botan::BlockCipher::encrypt ( byte block[] ) const

inlineinherited

Encrypt a block.

Parameters

block

the plaintext block to be encrypted Must be of length block_size(). Will hold the result when the function has finished.

Definition at line 66 of file block_cipher.h.

{ encrypt_n(block, block, 1); }

References encrypt_n().

encrypt() [2/2]

void Botan::BlockCipher::encrypt ( const byte in[], byte out[] ) const

inlineinherited

Encrypt a block.

Parameters

in	The plaintext block to be encrypted as a byte array. Must be of length block_size().
out	The byte array designated to hold the encrypted block. Must be of length block_size().

Definition at line 47 of file block_cipher.h.

         { encrypt_n(in, out, 1); }

References encrypt_n().

Referenced by Botan::aont_package(), and Botan::aont_unpackage().

encrypt_n()

void Botan::Lion::encrypt_n ( const byte in[], byte out[], size_t blocks ) const

virtual

Encrypt one or more blocks

Parameters

in	the input buffer (multiple of block_size())
out	the output buffer (same size as in)
blocks	the number of blocks to process

Implements Botan::BlockCipher.

Definition at line 17 of file lion.cpp.

   {
   SecureVector<byte> buffer_vec(LEFT_SIZE);
   byte* buffer = &buffer_vec[0];
 
   for(size_t i = 0; i != blocks; ++i)
      {
      xor_buf(buffer, in, &key1[0], LEFT_SIZE);
      cipher->set_key(buffer, LEFT_SIZE);
      cipher->cipher(in + LEFT_SIZE, out + LEFT_SIZE, RIGHT_SIZE);
 
      hash->update(out + LEFT_SIZE, RIGHT_SIZE);
      hash->final(buffer);
      xor_buf(out, in, buffer, LEFT_SIZE);
 
      xor_buf(buffer, out, &key2[0], LEFT_SIZE);
      cipher->set_key(buffer, LEFT_SIZE);
      cipher->cipher1(out + LEFT_SIZE, RIGHT_SIZE);
 
      in += BLOCK_SIZE;
      out += BLOCK_SIZE;
      }
   }

References Botan::xor_buf().

key_spec()

Key_Length_Specification Botan::Lion::key_spec ( ) const

inlinevirtual

Returns

object describing limits on key size

Implements Botan::SymmetricAlgorithm.

Definition at line 33 of file lion.h.

         {
         return Key_Length_Specification(2, 2*hash->output_length(), 2);
         }

maximum_keylength()

size_t Botan::SymmetricAlgorithm::maximum_keylength ( ) const

inlineinherited

Returns

minimum allowed key length

Definition at line 33 of file sym_algo.h.

         {
         return key_spec().maximum_keylength();
         }

References key_spec().

minimum_keylength()

size_t Botan::SymmetricAlgorithm::minimum_keylength ( ) const

inlineinherited

Returns

maxmium allowed key length

Definition at line 41 of file sym_algo.h.

         {
         return key_spec().minimum_keylength();
         }

References key_spec().

name()

std::string Botan::Lion::name ( ) const

virtual

Returns

name of this algorithm

Implements Botan::Algorithm.

Definition at line 82 of file lion.cpp.

   {
   return "Lion(" + hash->name() + "," +
                    cipher->name() + "," +
                    to_string(BLOCK_SIZE) + ")";
   }

References Botan::to_string().

Referenced by Lion().

parallel_bytes()

size_t Botan::BlockCipher::parallel_bytes ( ) const

inlineinherited

Returns

prefererred parallelism of this cipher in bytes

Definition at line 35 of file block_cipher.h.

         {
         return parallelism() * block_size() * BOTAN_BLOCK_CIPHER_PAR_MULT;
         }

References block_size(), and parallelism().

parallelism()

virtual size_t Botan::BlockCipher::parallelism ( ) const

inlinevirtualinherited

Returns

native parallelism of this cipher in blocks

Reimplemented in Botan::AES_128_NI, Botan::AES_192_NI, Botan::AES_256_NI, Botan::IDEA_SSE2, Botan::Noekeon_SIMD, Botan::Serpent_SIMD, and Botan::XTEA_SIMD.

Definition at line 30 of file block_cipher.h.

{ return 1; }

Referenced by parallel_bytes().

set_key() [1/2]

void Botan::SymmetricAlgorithm::set_key ( const byte key[], size_t length )

inlineinherited

Set the symmetric key of this object.

Parameters

key	the to be set as a byte array.
length	in bytes of key param

Definition at line 68 of file sym_algo.h.

         {
         if(!valid_keylength(length))
            throw Invalid_Key_Length(name(), length);
         key_schedule(key, length);
         }

References Botan::Algorithm::name(), and valid_keylength().

set_key() [2/2]

void Botan::SymmetricAlgorithm::set_key ( const SymmetricKey & key )

inlineinherited

Set the symmetric key of this object.

Parameters

key	the SymmetricKey to be set.

Definition at line 60 of file sym_algo.h.

         { set_key(key.begin(), key.length()); }

References Botan::OctetString::begin(), Botan::OctetString::length(), and set_key().

Referenced by Botan::aont_package(), Botan::aont_unpackage(), Botan::MAC_Filter::MAC_Filter(), Botan::MAC_Filter::MAC_Filter(), Botan::EAX_Base::set_key(), set_key(), Botan::Record_Reader::set_keys(), Botan::Record_Writer::set_keys(), Botan::StreamCipher_Filter::StreamCipher_Filter(), and Botan::StreamCipher_Filter::StreamCipher_Filter().

valid_keylength()

bool Botan::SymmetricAlgorithm::valid_keylength ( size_t length ) const

inlineinherited

Check whether a given key length is valid for this algorithm.

Parameters

length

the key length to be checked.

Returns

true if the key length is valid.

Definition at line 51 of file sym_algo.h.

         {
         return key_spec().valid_keylength(length);
         }

References key_spec().

Referenced by Botan::aont_package(), Botan::aont_unpackage(), set_key(), and Botan::EAX_Base::valid_keylength().

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

• src/block/lion/lion.h
• src/block/lion/lion.cpp