Botan  1.10.9
Public Types | Public Member Functions | List of all members
Botan::Twofish Class Reference

#include <twofish.h>

Inheritance diagram for Botan::Twofish:
Botan::Block_Cipher_Fixed_Params< 16, 16, 32, 8 > Botan::BlockCipher Botan::SymmetricAlgorithm Botan::Algorithm

Public Types

enum  
 

Public Member Functions

size_t block_size () const
 
void clear ()
 
BlockCipherclone () const
 
void decrypt (const byte in[], byte out[]) const
 
void decrypt (byte block[]) const
 
void decrypt_n (const byte in[], byte out[], size_t blocks) const
 
void encrypt (const byte in[], byte out[]) const
 
void encrypt (byte block[]) 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 SymmetricKey &key)
 
void set_key (const byte key[], size_t length)
 
 Twofish ()
 
bool valid_keylength (size_t length) const
 

Detailed Description

Twofish, an AES finalist

Definition at line 18 of file twofish.h.

Member Enumeration Documentation

anonymous enum
inherited

Constructor & Destructor Documentation

Botan::Twofish::Twofish ( )
inline

Definition at line 28 of file twofish.h.

28 : SB(1024), RK(40) {}

Member Function Documentation

size_t Botan::Block_Cipher_Fixed_Params< BS, KMIN, KMAX, KMOD >::block_size ( ) const
inlinevirtualinherited
Returns
block size of this algorithm

Implements Botan::BlockCipher.

Definition at line 108 of file block_cipher.h.

108 { return BS; }
void Botan::Twofish::clear ( )
virtual

Zeroize internal state

Implements Botan::Algorithm.

Definition at line 236 of file twofish.cpp.

References Botan::zeroise().

237  {
238  zeroise(SB);
239  zeroise(RK);
240  }
void zeroise(MemoryRegion< T > &vec)
Definition: secmem.h:415
BlockCipher* Botan::Twofish::clone ( ) const
inlinevirtual

Get a new object representing the same algorithm as *this

Implements Botan::BlockCipher.

Definition at line 26 of file twofish.h.

26 { return new Twofish; }
void Botan::BlockCipher::decrypt ( const byte  in[],
byte  out[] 
) const
inlineinherited

Decrypt a block.

Parameters
inThe ciphertext block to be decypted as a byte array. Must be of length block_size().
outThe byte array designated to hold the decrypted block. Must be of length block_size().

Definition at line 57 of file block_cipher.h.

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

58  { decrypt_n(in, out, 1); }
virtual void decrypt_n(const byte in[], byte out[], size_t blocks) const =0
void Botan::BlockCipher::decrypt ( byte  block[]) const
inlineinherited

Decrypt a block.

Parameters
blockthe 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.

74 { decrypt_n(block, block, 1); }
virtual void decrypt_n(const byte in[], byte out[], size_t blocks) const =0
void Botan::Twofish::decrypt_n ( const byte  in[],
byte  out[],
size_t  blocks 
) const
virtual

Decrypt one or more blocks

Parameters
inthe input buffer (multiple of block_size())
outthe output buffer (same size as in)
blocksthe number of blocks to process

Implements Botan::BlockCipher.

Definition at line 71 of file twofish.cpp.

References Botan::Block_Cipher_Fixed_Params< 16, 16, 32, 8 >::BLOCK_SIZE, Botan::get_byte(), Botan::load_le< u32bit >(), Botan::rotate_left(), Botan::rotate_right(), and Botan::store_le().

72  {
73  for(size_t i = 0; i != blocks; ++i)
74  {
75  u32bit A = load_le<u32bit>(in, 0) ^ RK[4];
76  u32bit B = load_le<u32bit>(in, 1) ^ RK[5];
77  u32bit C = load_le<u32bit>(in, 2) ^ RK[6];
78  u32bit D = load_le<u32bit>(in, 3) ^ RK[7];
79 
80  for(size_t j = 0; j != 16; j += 2)
81  {
82  u32bit X, Y;
83 
84  X = SB[ get_byte(3, A)] ^ SB[256+get_byte(2, A)] ^
85  SB[512+get_byte(1, A)] ^ SB[768+get_byte(0, A)];
86  Y = SB[ get_byte(0, B)] ^ SB[256+get_byte(3, B)] ^
87  SB[512+get_byte(2, B)] ^ SB[768+get_byte(1, B)];
88  X += Y;
89  Y += X + RK[39 - 2*j];
90  X += RK[38 - 2*j];
91 
92  C = rotate_left(C, 1) ^ X;
93  D = rotate_right(D ^ Y, 1);
94 
95  X = SB[ get_byte(3, C)] ^ SB[256+get_byte(2, C)] ^
96  SB[512+get_byte(1, C)] ^ SB[768+get_byte(0, C)];
97  Y = SB[ get_byte(0, D)] ^ SB[256+get_byte(3, D)] ^
98  SB[512+get_byte(2, D)] ^ SB[768+get_byte(1, D)];
99  X += Y;
100  Y += X + RK[37 - 2*j];
101  X += RK[36 - 2*j];
102 
103  A = rotate_left(A, 1) ^ X;
104  B = rotate_right(B ^ Y, 1);
105  }
106 
107  C ^= RK[0];
108  D ^= RK[1];
109  A ^= RK[2];
110  B ^= RK[3];
111 
112  store_le(out, C, D, A, B);
113 
114  in += BLOCK_SIZE;
115  out += BLOCK_SIZE;
116  }
117  }
void store_le(u16bit in, byte out[2])
Definition: loadstor.h:427
T rotate_left(T input, size_t rot)
Definition: rotate.h:21
byte get_byte(size_t byte_num, T input)
Definition: get_byte.h:21
T rotate_right(T input, size_t rot)
Definition: rotate.h:34
u32bit load_le< u32bit >(const byte in[], size_t off)
Definition: loadstor.h:183
unsigned int u32bit
Definition: types.h:32
void Botan::BlockCipher::encrypt ( const byte  in[],
byte  out[] 
) const
inlineinherited

Encrypt a block.

Parameters
inThe plaintext block to be encrypted as a byte array. Must be of length block_size().
outThe byte array designated to hold the encrypted block. Must be of length block_size().

Definition at line 47 of file block_cipher.h.

Referenced by Botan::aont_package(), Botan::aont_unpackage(), Botan::OFB::cipher(), Botan::DESX::encrypt_n(), Botan::CFB_Encryption::set_iv(), Botan::OFB::set_iv(), Botan::XTS_Encryption::set_iv(), Botan::CFB_Decryption::set_iv(), and Botan::XTS_Decryption::set_iv().

48  { encrypt_n(in, out, 1); }
virtual void encrypt_n(const byte in[], byte out[], size_t blocks) const =0
void Botan::BlockCipher::encrypt ( byte  block[]) const
inlineinherited

Encrypt a block.

Parameters
blockthe 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.

66 { encrypt_n(block, block, 1); }
virtual void encrypt_n(const byte in[], byte out[], size_t blocks) const =0
void Botan::Twofish::encrypt_n ( const byte  in[],
byte  out[],
size_t  blocks 
) const
virtual

Encrypt one or more blocks

Parameters
inthe input buffer (multiple of block_size())
outthe output buffer (same size as in)
blocksthe number of blocks to process

Implements Botan::BlockCipher.

Definition at line 20 of file twofish.cpp.

References Botan::Block_Cipher_Fixed_Params< 16, 16, 32, 8 >::BLOCK_SIZE, Botan::get_byte(), Botan::load_le< u32bit >(), Botan::rotate_left(), Botan::rotate_right(), and Botan::store_le().

21  {
22  for(size_t i = 0; i != blocks; ++i)
23  {
24  u32bit A = load_le<u32bit>(in, 0) ^ RK[0];
25  u32bit B = load_le<u32bit>(in, 1) ^ RK[1];
26  u32bit C = load_le<u32bit>(in, 2) ^ RK[2];
27  u32bit D = load_le<u32bit>(in, 3) ^ RK[3];
28 
29  for(size_t j = 0; j != 16; j += 2)
30  {
31  u32bit X, Y;
32 
33  X = SB[ get_byte(3, A)] ^ SB[256+get_byte(2, A)] ^
34  SB[512+get_byte(1, A)] ^ SB[768+get_byte(0, A)];
35  Y = SB[ get_byte(0, B)] ^ SB[256+get_byte(3, B)] ^
36  SB[512+get_byte(2, B)] ^ SB[768+get_byte(1, B)];
37  X += Y;
38  Y += X + RK[2*j + 9];
39  X += RK[2*j + 8];
40 
41  C = rotate_right(C ^ X, 1);
42  D = rotate_left(D, 1) ^ Y;
43 
44  X = SB[ get_byte(3, C)] ^ SB[256+get_byte(2, C)] ^
45  SB[512+get_byte(1, C)] ^ SB[768+get_byte(0, C)];
46  Y = SB[ get_byte(0, D)] ^ SB[256+get_byte(3, D)] ^
47  SB[512+get_byte(2, D)] ^ SB[768+get_byte(1, D)];
48  X += Y;
49  Y += X + RK[2*j + 11];
50  X += RK[2*j + 10];
51 
52  A = rotate_right(A ^ X, 1);
53  B = rotate_left(B, 1) ^ Y;
54  }
55 
56  C ^= RK[4];
57  D ^= RK[5];
58  A ^= RK[6];
59  B ^= RK[7];
60 
61  store_le(out, C, D, A, B);
62 
63  in += BLOCK_SIZE;
64  out += BLOCK_SIZE;
65  }
66  }
void store_le(u16bit in, byte out[2])
Definition: loadstor.h:427
T rotate_left(T input, size_t rot)
Definition: rotate.h:21
byte get_byte(size_t byte_num, T input)
Definition: get_byte.h:21
T rotate_right(T input, size_t rot)
Definition: rotate.h:34
u32bit load_le< u32bit >(const byte in[], size_t off)
Definition: loadstor.h:183
unsigned int u32bit
Definition: types.h:32
Key_Length_Specification Botan::Block_Cipher_Fixed_Params< BS, KMIN, KMAX, KMOD >::key_spec ( ) const
inlinevirtualinherited
Returns
object describing limits on key size

Implements Botan::SymmetricAlgorithm.

Definition at line 110 of file block_cipher.h.

111  {
112  return Key_Length_Specification(KMIN, KMAX, KMOD);
113  }
size_t Botan::SymmetricAlgorithm::maximum_keylength ( ) const
inlineinherited
Returns
minimum allowed key length

Definition at line 33 of file sym_algo.h.

34  {
35  return key_spec().maximum_keylength();
36  }
size_t maximum_keylength() const
Definition: key_spec.h:69
virtual Key_Length_Specification key_spec() const =0
size_t Botan::SymmetricAlgorithm::minimum_keylength ( ) const
inlineinherited
Returns
maxmium allowed key length

Definition at line 41 of file sym_algo.h.

42  {
43  return key_spec().minimum_keylength();
44  }
size_t minimum_keylength() const
Definition: key_spec.h:61
virtual Key_Length_Specification key_spec() const =0
std::string Botan::Twofish::name ( ) const
inlinevirtual
Returns
name of this algorithm

Implements Botan::Algorithm.

Definition at line 25 of file twofish.h.

25 { return "Twofish"; }
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.

References block_size.

36  {
37  return parallelism() * block_size() * BOTAN_BLOCK_CIPHER_PAR_MULT;
38  }
virtual size_t parallelism() const
Definition: block_cipher.h:30
virtual size_t block_size() const =0
virtual size_t Botan::BlockCipher::parallelism ( ) const
inlinevirtualinherited
Returns
native parallelism of this cipher in blocks

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

Definition at line 30 of file block_cipher.h.

30 { return 1; }
void Botan::SymmetricAlgorithm::set_key ( const SymmetricKey key)
inlineinherited
void Botan::SymmetricAlgorithm::set_key ( const byte  key[],
size_t  length 
)
inlineinherited

Set the symmetric key of this object.

Parameters
keythe to be set as a byte array.
lengthin bytes of key param

Definition at line 68 of file sym_algo.h.

69  {
70  if(!valid_keylength(length))
71  throw Invalid_Key_Length(name(), length);
72  key_schedule(key, length);
73  }
bool valid_keylength(size_t length) const
Definition: sym_algo.h:51
virtual std::string name() const =0
bool Botan::SymmetricAlgorithm::valid_keylength ( size_t  length) const
inlineinherited

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

Parameters
lengththe key length to be checked.
Returns
true if the key length is valid.

Definition at line 51 of file sym_algo.h.

Referenced by Botan::aont_package(), Botan::aont_unpackage(), Botan::HMAC_RNG::HMAC_RNG(), Botan::Lion::Lion(), Botan::Randpool::Randpool(), and Botan::EAX_Base::valid_keylength().

52  {
53  return key_spec().valid_keylength(length);
54  }
bool valid_keylength(size_t length) const
Definition: key_spec.h:51
virtual Key_Length_Specification key_spec() const =0

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