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

#include <lion.h>

Inheritance diagram for Botan::Lion:
Botan::BlockCipher Botan::SymmetricAlgorithm Botan::Algorithm

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
 
 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 SymmetricKey &key)
 
void set_key (const byte key[], size_t length)
 
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

Botan::Lion::Lion ( HashFunction hash,
StreamCipher cipher,
size_t  block_size 
)
Parameters
hashthe hash to use internally
cipherthe stream cipher to use internally
block_sizethe size of the block to use

Definition at line 111 of file lion.cpp.

References name(), Botan::MemoryRegion< T >::resize(), and Botan::SymmetricAlgorithm::valid_keylength().

Referenced by clone().

111  :
112  BLOCK_SIZE(std::max<size_t>(2*hash_in->output_length() + 1, block_len)),
113  LEFT_SIZE(hash_in->output_length()),
114  RIGHT_SIZE(BLOCK_SIZE - LEFT_SIZE),
115  hash(hash_in),
116  cipher(sc_in)
117  {
118  if(2*LEFT_SIZE + 1 > BLOCK_SIZE)
119  throw Invalid_Argument(name() + ": Chosen block size is too small");
120 
121  if(!cipher->valid_keylength(LEFT_SIZE))
122  throw Invalid_Argument(name() + ": This stream/hash combo is invalid");
123 
124  key1.resize(LEFT_SIZE);
125  key2.resize(LEFT_SIZE);
126  }
void resize(size_t n)
Definition: secmem.h:211
std::invalid_argument Invalid_Argument
Definition: exceptn.h:20
bool valid_keylength(size_t length) const
Definition: sym_algo.h:51
std::string name() const
Definition: lion.cpp:82
Botan::Lion::~Lion ( )
inline

Definition at line 51 of file lion.h.

51 { delete hash; delete cipher; }

Member Function Documentation

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.

31 { return BLOCK_SIZE; }
void Botan::Lion::clear ( )
virtual

Zeroize internal state

Implements Botan::Algorithm.

Definition at line 100 of file lion.cpp.

References Botan::Algorithm::clear(), and Botan::zeroise().

101  {
102  hash->clear();
103  cipher->clear();
104  zeroise(key1);
105  zeroise(key2);
106  }
virtual void clear()=0
void zeroise(MemoryRegion< T > &vec)
Definition: secmem.h:415
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.

References Botan::HashFunction::clone(), Botan::StreamCipher::clone(), and Lion().

93  {
94  return new Lion(hash->clone(), cipher->clone(), BLOCK_SIZE);
95  }
virtual HashFunction * clone() const =0
virtual StreamCipher * clone() const =0
Lion(HashFunction *hash, StreamCipher *cipher, size_t block_size)
Definition: lion.cpp:111
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::Lion::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 44 of file lion.cpp.

References Botan::StreamCipher::cipher(), Botan::StreamCipher::cipher1(), Botan::Buffered_Computation::final(), Botan::SymmetricAlgorithm::set_key(), Botan::Buffered_Computation::update(), and Botan::xor_buf().

45  {
46  SecureVector<byte> buffer_vec(LEFT_SIZE);
47  byte* buffer = &buffer_vec[0];
48 
49  for(size_t i = 0; i != blocks; ++i)
50  {
51  xor_buf(buffer, in, &key2[0], LEFT_SIZE);
52  cipher->set_key(buffer, LEFT_SIZE);
53  cipher->cipher(in + LEFT_SIZE, out + LEFT_SIZE, RIGHT_SIZE);
54 
55  hash->update(out + LEFT_SIZE, RIGHT_SIZE);
56  hash->final(buffer);
57  xor_buf(out, in, buffer, LEFT_SIZE);
58 
59  xor_buf(buffer, out, &key1[0], LEFT_SIZE);
60  cipher->set_key(buffer, LEFT_SIZE);
61  cipher->cipher1(out + LEFT_SIZE, RIGHT_SIZE);
62 
63  in += BLOCK_SIZE;
64  out += BLOCK_SIZE;
65  }
66  }
void cipher1(byte buf[], size_t len)
Definition: stream_cipher.h:34
unsigned char byte
Definition: types.h:22
void set_key(const SymmetricKey &key)
Definition: sym_algo.h:60
void update(const byte in[], size_t length)
Definition: buf_comp.h:33
virtual void cipher(const byte in[], byte out[], size_t len)=0
void final(byte out[])
Definition: buf_comp.h:80
void xor_buf(byte out[], const byte in[], size_t length)
Definition: xor_buf.h:21
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::Lion::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 17 of file lion.cpp.

References Botan::StreamCipher::cipher(), Botan::StreamCipher::cipher1(), Botan::Buffered_Computation::final(), Botan::SymmetricAlgorithm::set_key(), Botan::Buffered_Computation::update(), and Botan::xor_buf().

18  {
19  SecureVector<byte> buffer_vec(LEFT_SIZE);
20  byte* buffer = &buffer_vec[0];
21 
22  for(size_t i = 0; i != blocks; ++i)
23  {
24  xor_buf(buffer, in, &key1[0], LEFT_SIZE);
25  cipher->set_key(buffer, LEFT_SIZE);
26  cipher->cipher(in + LEFT_SIZE, out + LEFT_SIZE, RIGHT_SIZE);
27 
28  hash->update(out + LEFT_SIZE, RIGHT_SIZE);
29  hash->final(buffer);
30  xor_buf(out, in, buffer, LEFT_SIZE);
31 
32  xor_buf(buffer, out, &key2[0], LEFT_SIZE);
33  cipher->set_key(buffer, LEFT_SIZE);
34  cipher->cipher1(out + LEFT_SIZE, RIGHT_SIZE);
35 
36  in += BLOCK_SIZE;
37  out += BLOCK_SIZE;
38  }
39  }
void cipher1(byte buf[], size_t len)
Definition: stream_cipher.h:34
unsigned char byte
Definition: types.h:22
void set_key(const SymmetricKey &key)
Definition: sym_algo.h:60
void update(const byte in[], size_t length)
Definition: buf_comp.h:33
virtual void cipher(const byte in[], byte out[], size_t len)=0
void final(byte out[])
Definition: buf_comp.h:80
void xor_buf(byte out[], const byte in[], size_t length)
Definition: xor_buf.h:21
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.

34  {
35  return Key_Length_Specification(2, 2*hash->output_length(), 2);
36  }
virtual size_t output_length() const =0
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::Lion::name ( ) const
virtual
Returns
name of this algorithm

Implements Botan::Algorithm.

Definition at line 82 of file lion.cpp.

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

Referenced by Lion().

83  {
84  return "Lion(" + hash->name() + "," +
85  cipher->name() + "," +
86  to_string(BLOCK_SIZE) + ")";
87  }
virtual std::string name() const =0
std::string to_string(u64bit n, size_t min_len)
Definition: parsing.cpp:42
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(), 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: