Botan::XTEA Class Reference

#include <xtea.h>

Inheritance diagram for Botan::XTEA:

Public Types
enum

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
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
	XTEA ()

Protected Member Functions
const SecureVector< u32bit > &	get_EK () const

Detailed Description

XTEA

Definition at line 18 of file xtea.h.

Member Enumeration Documentation

anonymous enum

anonymous enum

inherited

Definition at line 107 of file block_cipher.h.

{ BLOCK_SIZE = BS };

Constructor & Destructor Documentation

XTEA()

Botan::XTEA::XTEA ( )

inline

Definition at line 28 of file xtea.h.

: EK(64) {}

Referenced by clone().

Member Function Documentation

block_size()

size_t Botan::Block_Cipher_Fixed_Params< BS, KMIN, 0, 1 >::block_size ( ) const

inlinevirtualinherited

Returns

block size of this algorithm

Implements Botan::BlockCipher.

Definition at line 108 of file block_cipher.h.

{ return BS; }

clear()

void Botan::XTEA::clear ( )

inlinevirtual

Zeroize internal state

Implements Botan::Algorithm.

Definition at line 24 of file xtea.h.

{ zeroise(EK); }

References Botan::zeroise().

clone()

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

inlinevirtual

Get a new object representing the same algorithm as *this

Implements Botan::BlockCipher.

Reimplemented in Botan::XTEA_SIMD.

Definition at line 26 of file xtea.h.

{ return new XTEA; }

References XTEA().

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); }

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); }

decrypt_n()

void Botan::XTEA::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.

Reimplemented in Botan::XTEA_SIMD.

Definition at line 93 of file xtea.cpp.

   {
   while(blocks >= 4)
      {
      xtea_decrypt_4(in, out, &(this->EK[0]));
      in += 4 * BLOCK_SIZE;
      out += 4 * BLOCK_SIZE;
      blocks -= 4;
      }
 
   for(size_t i = 0; i != blocks; ++i)
      {
      u32bit L = load_be<u32bit>(in, 0);
      u32bit R = load_be<u32bit>(in, 1);
 
      for(size_t j = 0; j != 32; ++j)
         {
         R -= (((L << 4) ^ (L >> 5)) + L) ^ EK[63 - 2*j];
         L -= (((R << 4) ^ (R >> 5)) + R) ^ EK[62 - 2*j];
         }
 
      store_be(out, L, R);
 
      in += BLOCK_SIZE;
      out += BLOCK_SIZE;
      }
   }

References Botan::Block_Cipher_Fixed_Params< 8, 16 >::BLOCK_SIZE, Botan::load_be(), and Botan::store_be().

Referenced by Botan::XTEA_SIMD::decrypt_n().

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); }

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); }

encrypt_n()

void Botan::XTEA::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.

Reimplemented in Botan::XTEA_SIMD.

Definition at line 62 of file xtea.cpp.

   {
   while(blocks >= 4)
      {
      xtea_encrypt_4(in, out, &(this->EK[0]));
      in += 4 * BLOCK_SIZE;
      out += 4 * BLOCK_SIZE;
      blocks -= 4;
      }
 
   for(size_t i = 0; i != blocks; ++i)
      {
      u32bit L = load_be<u32bit>(in, 0);
      u32bit R = load_be<u32bit>(in, 1);
 
      for(size_t j = 0; j != 32; ++j)
         {
         L += (((R << 4) ^ (R >> 5)) + R) ^ EK[2*j];
         R += (((L << 4) ^ (L >> 5)) + L) ^ EK[2*j+1];
         }
 
      store_be(out, L, R);
 
      in += BLOCK_SIZE;
      out += BLOCK_SIZE;
      }
   }

References Botan::Block_Cipher_Fixed_Params< 8, 16 >::BLOCK_SIZE, Botan::load_be(), and Botan::store_be().

Referenced by Botan::XTEA_SIMD::encrypt_n().

get_EK()

const SecureVector< u32bit > & Botan::XTEA::get_EK ( ) const

inlineprotected

Returns

const reference to the key schedule

Definition at line 33 of file xtea.h.

{ return EK; }

Referenced by Botan::XTEA_SIMD::decrypt_n(), and Botan::XTEA_SIMD::encrypt_n().

key_spec()

Key_Length_Specification Botan::Block_Cipher_Fixed_Params< BS, KMIN, 0, 1 >::key_spec ( ) const

inlinevirtualinherited

Returns

object describing limits on key size

Implements Botan::SymmetricAlgorithm.

Definition at line 110 of file block_cipher.h.

         {
         return Key_Length_Specification(KMIN, KMAX, KMOD);
         }

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();
         }

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();
         }

name()

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

inlinevirtual

Returns

name of this algorithm

Implements Botan::Algorithm.

Definition at line 25 of file xtea.h.

{ return "XTEA"; }

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;
         }

parallelism()

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

inlinevirtualinherited

Returns

native parallelism of this cipher in blocks

Definition at line 30 of file block_cipher.h.

{ return 1; }

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);
         }

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()); }

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);
         }

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

• src/block/xtea/xtea.h
• src/block/xtea/xtea.cpp