Botan  2.9.0
Crypto and TLS for C++11
Public Member Functions | Protected Member Functions | List of all members
Botan::GHASH Class Referencefinal

#include <ghash.h>

Inheritance diagram for Botan::GHASH:
Botan::SymmetricAlgorithm

Public Member Functions

void add_final_block (secure_vector< uint8_t > &x, size_t ad_len, size_t pt_len)
 
void clear () override
 
secure_vector< uint8_t > final ()
 
void ghash_update (secure_vector< uint8_t > &x, const uint8_t input[], size_t input_len)
 
Key_Length_Specification key_spec () const override
 
size_t maximum_keylength () const
 
size_t minimum_keylength () const
 
std::string name () const override
 
secure_vector< uint8_t > nonce_hash (const uint8_t nonce[], size_t len)
 
std::string provider () const
 
void reset ()
 
void set_associated_data (const uint8_t ad[], size_t ad_len)
 
void set_key (const SymmetricKey &key)
 
template<typename Alloc >
void set_key (const std::vector< uint8_t, Alloc > &key)
 
void set_key (const uint8_t key[], size_t length)
 
void start (const uint8_t nonce[], size_t len)
 
void update (const uint8_t in[], size_t len)
 
void update_associated_data (const uint8_t ad[], size_t len)
 
bool valid_keylength (size_t length) const
 

Protected Member Functions

void verify_key_set (bool cond) const
 

Detailed Description

GCM's GHASH This is not intended for general use, but is exposed to allow shared code between GCM and GMAC

Definition at line 20 of file ghash.h.

Member Function Documentation

◆ add_final_block()

void Botan::GHASH::add_final_block ( secure_vector< uint8_t > &  x,
size_t  ad_len,
size_t  pt_len 
)

Definition at line 221 of file ghash.cpp.

References ghash_update(), and hash.

Referenced by final(), and nonce_hash().

223  {
224  /*
225  * stack buffer is fine here since the text len is public
226  * and the length of the AD is probably not sensitive either.
227  */
228  uint8_t final_block[GCM_BS];
229  store_be<uint64_t>(final_block, 8*ad_len, 8*text_len);
230  ghash_update(hash, final_block, GCM_BS);
231  }
void ghash_update(secure_vector< uint8_t > &x, const uint8_t input[], size_t input_len)
Definition: ghash.cpp:112
MechanismType hash

◆ clear()

void Botan::GHASH::clear ( )
overridevirtual

Reset the state.

Implements Botan::SymmetricAlgorithm.

Definition at line 256 of file ghash.cpp.

References reset(), and Botan::zap().

257  {
258  zap(m_H);
259  zap(m_HM);
260  reset();
261  }
void reset()
Definition: ghash.cpp:263
void zap(std::vector< T, Alloc > &vec)
Definition: secmem.h:170

◆ final()

secure_vector< uint8_t > Botan::GHASH::final ( )

Definition at line 233 of file ghash.cpp.

References add_final_block().

234  {
235  add_final_block(m_ghash, m_ad_len, m_text_len);
236 
237  secure_vector<uint8_t> mac;
238  mac.swap(m_ghash);
239 
240  mac ^= m_nonce;
241  m_text_len = 0;
242  return mac;
243  }
void add_final_block(secure_vector< uint8_t > &x, size_t ad_len, size_t pt_len)
Definition: ghash.cpp:221

◆ ghash_update()

void Botan::GHASH::ghash_update ( secure_vector< uint8_t > &  x,
const uint8_t  input[],
size_t  input_len 
)

Definition at line 112 of file ghash.cpp.

References Botan::copy_mem(), and Botan::SymmetricAlgorithm::verify_key_set().

Referenced by add_final_block(), nonce_hash(), set_associated_data(), update(), and update_associated_data().

114  {
115  verify_key_set(m_HM.size());
116 
117  /*
118  This assumes if less than block size input then we're just on the
119  final block and should pad with zeros
120  */
121 
122  const size_t full_blocks = length / GCM_BS;
123  const size_t final_bytes = length - (full_blocks * GCM_BS);
124 
125  if(full_blocks > 0)
126  {
127  gcm_multiply(ghash, input, full_blocks);
128  }
129 
130  if(final_bytes)
131  {
132  secure_vector<uint8_t> last_block(GCM_BS);
133  copy_mem(last_block.data(), input + full_blocks * GCM_BS, final_bytes);
134  gcm_multiply(ghash, last_block.data(), 1);
135  }
136  }
void verify_key_set(bool cond) const
Definition: sym_algo.h:89
void copy_mem(T *out, const T *in, size_t n)
Definition: mem_ops.h:122

◆ key_spec()

Key_Length_Specification Botan::GHASH::key_spec ( ) const
inlineoverridevirtual
Returns
object describing limits on key size

Implements Botan::SymmetricAlgorithm.

Definition at line 41 of file ghash.h.

42  { return Key_Length_Specification(16); }

◆ maximum_keylength()

size_t Botan::SymmetricAlgorithm::maximum_keylength ( ) const
inlineinherited
Returns
minimum allowed key length

Definition at line 38 of file sym_algo.h.

39  {
40  return key_spec().maximum_keylength();
41  }
size_t maximum_keylength() const
Definition: key_spec.h:69
virtual Key_Length_Specification key_spec() const =0

◆ minimum_keylength()

size_t Botan::SymmetricAlgorithm::minimum_keylength ( ) const
inlineinherited
Returns
maximum allowed key length

Definition at line 46 of file sym_algo.h.

Referenced by botan_block_cipher_get_keyspec(), and botan_mac_get_keyspec().

47  {
48  return key_spec().minimum_keylength();
49  }
virtual Key_Length_Specification key_spec() const =0
size_t minimum_keylength() const
Definition: key_spec.h:61

◆ name()

std::string Botan::GHASH::name ( ) const
inlineoverridevirtual
Returns
the algorithm name

Implements Botan::SymmetricAlgorithm.

Definition at line 48 of file ghash.h.

48 { return "GHASH"; }

◆ nonce_hash()

secure_vector< uint8_t > Botan::GHASH::nonce_hash ( const uint8_t  nonce[],
size_t  len 
)

Definition at line 245 of file ghash.cpp.

References add_final_block(), BOTAN_ASSERT, and ghash_update().

246  {
247  BOTAN_ASSERT(m_ghash.size() == 0, "nonce_hash called during wrong time");
248  secure_vector<uint8_t> y0(GCM_BS);
249 
250  ghash_update(y0, nonce, nonce_len);
251  add_final_block(y0, 0, nonce_len);
252 
253  return y0;
254  }
void add_final_block(secure_vector< uint8_t > &x, size_t ad_len, size_t pt_len)
Definition: ghash.cpp:221
void ghash_update(secure_vector< uint8_t > &x, const uint8_t input[], size_t input_len)
Definition: ghash.cpp:112
#define BOTAN_ASSERT(expr, assertion_made)
Definition: assert.h:55

◆ provider()

std::string Botan::GHASH::provider ( ) const

Definition at line 29 of file ghash.cpp.

30  {
31 #if defined(BOTAN_HAS_GCM_CLMUL)
32  if(CPUID::has_clmul())
33  return "clmul";
34 #endif
35 
36 #if defined(BOTAN_HAS_GCM_CLMUL_SSSE3)
37  if(CPUID::has_ssse3())
38  return "ssse3";
39 #endif
40 
41 #if defined(BOTAN_HAS_GCM_PMULL)
42  if(CPUID::has_arm_pmull())
43  return "pmull";
44 #endif
45 
46  return "base";
47  }

◆ reset()

void Botan::GHASH::reset ( )

Definition at line 263 of file ghash.cpp.

References Botan::zeroise().

Referenced by clear().

264  {
265  zeroise(m_H_ad);
266  m_ghash.clear();
267  m_nonce.clear();
268  m_text_len = m_ad_len = 0;
269  }
void zeroise(std::vector< T, Alloc > &vec)
Definition: secmem.h:160

◆ set_associated_data()

void Botan::GHASH::set_associated_data ( const uint8_t  ad[],
size_t  ad_len 
)

Definition at line 196 of file ghash.cpp.

References ghash_update(), and Botan::zeroise().

197  {
198  if(m_ghash.empty() == false)
199  throw Invalid_State("Too late to set AD in GHASH");
200 
201  zeroise(m_H_ad);
202 
203  ghash_update(m_H_ad, input, length);
204  m_ad_len = length;
205  }
void ghash_update(secure_vector< uint8_t > &x, const uint8_t input[], size_t input_len)
Definition: ghash.cpp:112
void zeroise(std::vector< T, Alloc > &vec)
Definition: secmem.h:160

◆ set_key() [1/3]

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

Set the symmetric key of this object.

Parameters
keythe SymmetricKey to be set.

Definition at line 65 of file sym_algo.h.

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

Referenced by Botan::aont_package(), Botan::aont_unpackage(), botan_block_cipher_set_key(), botan_cipher_set_key(), botan_mac_set_key(), Botan::FPE::fe1_decrypt(), and Botan::FPE::fe1_encrypt().

66  {
67  set_key(key.begin(), key.length());
68  }
void set_key(const SymmetricKey &key)
Definition: sym_algo.h:65

◆ set_key() [2/3]

template<typename Alloc >
void Botan::SymmetricAlgorithm::set_key ( const std::vector< uint8_t, Alloc > &  key)
inlineinherited

Definition at line 71 of file sym_algo.h.

72  {
73  set_key(key.data(), key.size());
74  }
void set_key(const SymmetricKey &key)
Definition: sym_algo.h:65

◆ set_key() [3/3]

void Botan::SymmetricAlgorithm::set_key ( const uint8_t  key[],
size_t  length 
)
inherited

Set the symmetric key of this object.

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

Definition at line 17 of file sym_algo.cpp.

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

18  {
19  if(!valid_keylength(length))
20  throw Invalid_Key_Length(name(), length);
21  key_schedule(key, length);
22  }
bool valid_keylength(size_t length) const
Definition: sym_algo.h:56
virtual std::string name() const =0

◆ start()

void Botan::GHASH::start ( const uint8_t  nonce[],
size_t  len 
)

Definition at line 189 of file ghash.cpp.

References BOTAN_ARG_CHECK.

190  {
191  BOTAN_ARG_CHECK(len == 16, "GHASH requires a 128-bit nonce");
192  m_nonce.assign(nonce, nonce + len);
193  m_ghash = m_H_ad;
194  }
#define BOTAN_ARG_CHECK(expr, msg)
Definition: assert.h:37

◆ update()

void Botan::GHASH::update ( const uint8_t  in[],
size_t  len 
)

Definition at line 214 of file ghash.cpp.

References ghash_update(), and Botan::SymmetricAlgorithm::verify_key_set().

215  {
216  verify_key_set(m_ghash.size() == GCM_BS);
217  m_text_len += length;
218  ghash_update(m_ghash, input, length);
219  }
void verify_key_set(bool cond) const
Definition: sym_algo.h:89
void ghash_update(secure_vector< uint8_t > &x, const uint8_t input[], size_t input_len)
Definition: ghash.cpp:112

◆ update_associated_data()

void Botan::GHASH::update_associated_data ( const uint8_t  ad[],
size_t  len 
)

Definition at line 207 of file ghash.cpp.

References ghash_update(), and Botan::SymmetricAlgorithm::verify_key_set().

208  {
209  verify_key_set(m_ghash.size() == GCM_BS);
210  m_ad_len += length;
211  ghash_update(m_ghash, ad, length);
212  }
void verify_key_set(bool cond) const
Definition: sym_algo.h:89
void ghash_update(secure_vector< uint8_t > &x, const uint8_t input[], size_t input_len)
Definition: ghash.cpp:112

◆ valid_keylength()

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 56 of file sym_algo.h.

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

57  {
58  return key_spec().valid_keylength(length);
59  }
bool valid_keylength(size_t length) const
Definition: key_spec.h:51
virtual Key_Length_Specification key_spec() const =0

◆ verify_key_set()

void Botan::SymmetricAlgorithm::verify_key_set ( bool  cond) const
inlineprotectedinherited

Definition at line 89 of file sym_algo.h.

Referenced by Botan::Salsa20::cipher(), Botan::CTR_BE::cipher(), Botan::RC4::cipher(), Botan::SHAKE_128_Cipher::cipher(), Botan::ChaCha::cipher(), Botan::SHACAL2::decrypt_n(), Botan::Twofish::decrypt_n(), Botan::AES_128::decrypt_n(), Botan::KASUMI::decrypt_n(), Botan::Noekeon::decrypt_n(), Botan::CAST_256::decrypt_n(), Botan::SM4::decrypt_n(), Botan::DES::decrypt_n(), Botan::DESX::decrypt_n(), Botan::XTEA::decrypt_n(), Botan::Camellia_128::decrypt_n(), Botan::IDEA::decrypt_n(), Botan::CAST_128::decrypt_n(), Botan::MISTY1::decrypt_n(), Botan::SEED::decrypt_n(), Botan::Blowfish::decrypt_n(), Botan::Serpent::decrypt_n(), Botan::Threefish_512::decrypt_n(), Botan::Lion::decrypt_n(), Botan::ARIA_128::decrypt_n(), Botan::Camellia_192::decrypt_n(), Botan::TripleDES::decrypt_n(), Botan::ARIA_192::decrypt_n(), Botan::Camellia_256::decrypt_n(), Botan::GOST_28147_89::decrypt_n(), Botan::AES_192::decrypt_n(), Botan::ARIA_256::decrypt_n(), Botan::AES_256::decrypt_n(), Botan::SEED::encrypt_n(), Botan::CAST_256::encrypt_n(), Botan::SHACAL2::encrypt_n(), Botan::SM4::encrypt_n(), Botan::IDEA::encrypt_n(), Botan::KASUMI::encrypt_n(), Botan::AES_128::encrypt_n(), Botan::MISTY1::encrypt_n(), Botan::Noekeon::encrypt_n(), Botan::CAST_128::encrypt_n(), Botan::DES::encrypt_n(), Botan::Blowfish::encrypt_n(), Botan::Twofish::encrypt_n(), Botan::Camellia_128::encrypt_n(), Botan::XTEA::encrypt_n(), Botan::DESX::encrypt_n(), Botan::Threefish_512::encrypt_n(), Botan::Serpent::encrypt_n(), Botan::Lion::encrypt_n(), Botan::ARIA_128::encrypt_n(), Botan::Camellia_192::encrypt_n(), Botan::TripleDES::encrypt_n(), Botan::ARIA_192::encrypt_n(), Botan::Camellia_256::encrypt_n(), Botan::GOST_28147_89::encrypt_n(), Botan::AES_192::encrypt_n(), Botan::ARIA_256::encrypt_n(), Botan::AES_256::encrypt_n(), Botan::OCB_Encryption::finish(), Botan::OCB_Decryption::finish(), ghash_update(), Botan::CFB_Encryption::process(), Botan::CFB_Decryption::process(), Botan::Salsa20::seek(), Botan::CTR_BE::seek(), Botan::ChaCha::seek(), Botan::OCB_Mode::set_associated_data(), Botan::Salsa20::set_iv(), Botan::ChaCha::set_iv(), update(), update_associated_data(), and Botan::ChaCha::write_keystream().

90  {
91  if(cond == false)
92  throw_key_not_set_error();
93  }

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