Botan  2.4.0
Crypto and TLS for C++11
Public Member Functions | Static Public Member Functions | Protected Member Functions | List of all members
Botan::TLS::TLS_CBC_HMAC_AEAD_Decryption Class Referencefinal

#include <tls_cbc.h>

Inheritance diagram for Botan::TLS::TLS_CBC_HMAC_AEAD_Decryption:
Botan::TLS::TLS_CBC_HMAC_AEAD_Mode Botan::AEAD_Mode Botan::Cipher_Mode

Public Member Functions

bool authenticated () const override
 
void clear () override final
 
size_t default_nonce_length () const override final
 
void finish (secure_vector< uint8_t > &final_block, size_t offset=0) override
 
Key_Length_Specification key_spec () const override final
 
size_t minimum_final_size () const override
 
std::string name () const override final
 
size_t output_length (size_t input_length) const override
 
size_t process (uint8_t buf[], size_t sz) override final
 
virtual std::string provider () const
 
void reset () override final
 
template<typename Alloc >
void set_ad (const std::vector< uint8_t, Alloc > &ad)
 
void set_associated_data (const uint8_t ad[], size_t ad_len) override
 
template<typename Alloc >
void set_associated_data_vec (const std::vector< uint8_t, Alloc > &ad)
 
template<typename Alloc >
void set_key (const std::vector< uint8_t, Alloc > &key)
 
void set_key (const SymmetricKey &key)
 
void set_key (const uint8_t key[], size_t length)
 
template<typename Alloc >
void start (const std::vector< uint8_t, Alloc > &nonce)
 
void start (const uint8_t nonce[], size_t nonce_len)
 
void start ()
 
size_t tag_size () const override final
 
 TLS_CBC_HMAC_AEAD_Decryption (const std::string &cipher_algo, const size_t cipher_keylen, const std::string &mac_algo, const size_t mac_keylen, bool use_explicit_iv, bool use_encrypt_then_mac)
 
void update (secure_vector< uint8_t > &buffer, size_t offset=0)
 
size_t update_granularity () const override final
 
bool valid_keylength (size_t length) const
 
bool valid_nonce_length (size_t nl) const override final
 

Static Public Member Functions

static std::vector< std::string > providers (const std::string &algo_spec)
 

Protected Member Functions

std::vector< uint8_t > & assoc_data ()
 
std::vector< uint8_t > assoc_data_with_len (uint16_t len)
 
size_t block_size () const
 
Cipher_Modecbc () const
 
secure_vector< uint8_t > & cbc_state ()
 
size_t cipher_keylen () const
 
size_t iv_size () const
 
MessageAuthenticationCodemac () const
 
size_t mac_keylen () const
 
secure_vector< uint8_t > & msg ()
 
bool use_encrypt_then_mac () const
 

Detailed Description

TLS_CBC_HMAC_AEAD Decryption

Definition at line 136 of file tls_cbc.h.

Constructor & Destructor Documentation

◆ TLS_CBC_HMAC_AEAD_Decryption()

Botan::TLS::TLS_CBC_HMAC_AEAD_Decryption::TLS_CBC_HMAC_AEAD_Decryption ( const std::string &  cipher_algo,
const size_t  cipher_keylen,
const std::string &  mac_algo,
const size_t  mac_keylen,
bool  use_explicit_iv,
bool  use_encrypt_then_mac 
)
inline

Definition at line 141 of file tls_cbc.h.

146  :
148  cipher_algo,
150  mac_algo,
151  mac_keylen,
152  use_explicit_iv,
154  {}
TLS_CBC_HMAC_AEAD_Mode(Cipher_Dir direction, const std::string &cipher_name, size_t cipher_keylen, const std::string &mac_name, size_t mac_keylen, bool use_explicit_iv, bool use_encrypt_then_mac)
Definition: tls_cbc.cpp:26

Member Function Documentation

◆ assoc_data()

std::vector<uint8_t>& Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::assoc_data ( )
inlineprotectedinherited

◆ assoc_data_with_len()

std::vector< uint8_t > Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::assoc_data_with_len ( uint16_t  len)
protectedinherited

Definition at line 121 of file tls_cbc.cpp.

References BOTAN_ASSERT, and Botan::get_byte().

Referenced by finish().

122  {
123  std::vector<uint8_t> ad = m_ad;
124  BOTAN_ASSERT(ad.size() == 13, "Expected AAD size");
125  ad[11] = get_byte(0, len);
126  ad[12] = get_byte(1, len);
127  return ad;
128  }
#define BOTAN_ASSERT(expr, assertion_made)
Definition: assert.h:29
uint8_t get_byte(size_t byte_num, T input)
Definition: loadstor.h:39

◆ authenticated()

bool Botan::AEAD_Mode::authenticated ( ) const
inlineoverridevirtualinherited
Returns
true iff this mode provides authentication as well as confidentiality.

Reimplemented from Botan::Cipher_Mode.

Definition at line 25 of file aead.h.

25 { return true; }

◆ block_size()

size_t Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::block_size ( ) const
inlineprotectedinherited

◆ cbc()

Cipher_Mode& Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::cbc ( ) const
inlineprotectedinherited

◆ cbc_state()

secure_vector<uint8_t>& Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::cbc_state ( )
inlineprotectedinherited

◆ cipher_keylen()

size_t Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::cipher_keylen ( ) const
inlineprotectedinherited

Definition at line 56 of file tls_cbc.h.

56 { return m_cipher_keylen; }

◆ clear()

void Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::clear ( )
finaloverridevirtualinherited

Zeroise all state See also reset_msg()

Implements Botan::Cipher_Mode.

Definition at line 53 of file tls_cbc.cpp.

References Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::cbc(), Botan::SymmetricAlgorithm::clear(), Botan::Cipher_Mode::clear(), Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::mac(), and Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::reset().

54  {
55  cbc().clear();
56  mac().clear();
57  reset();
58  }
virtual void clear()=0
Cipher_Mode & cbc() const
Definition: tls_cbc.h:63
MessageAuthenticationCode & mac() const
Definition: tls_cbc.h:65
virtual void clear()=0
void reset() override final
Definition: tls_cbc.cpp:60

◆ default_nonce_length()

size_t Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::default_nonce_length ( ) const
inlinefinaloverridevirtualinherited
Returns
default AEAD nonce size (a commonly supported value among AEAD modes, and large enough that random collisions are unlikely)

Reimplemented from Botan::AEAD_Mode.

Definition at line 41 of file tls_cbc.h.

41 { return m_iv_size; }

◆ finish()

void Botan::TLS::TLS_CBC_HMAC_AEAD_Decryption::finish ( secure_vector< uint8_t > &  final_block,
size_t  offset = 0 
)
overridevirtual

Complete processing of a message.

Parameters
final_blockin/out parameter which must be at least minimum_final_size() bytes, and will be set to any final output
offsetan offset into final_block to begin processing

Implements Botan::Cipher_Mode.

Definition at line 351 of file tls_cbc.cpp.

References Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::assoc_data_with_len(), Botan::TLS::Alert::BAD_RECORD_MAC, Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::block_size(), Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::cbc_state(), Botan::TLS::check_tls_cbc_padding(), Botan::constant_time_compare(), Botan::Buffered_Computation::final(), Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::iv_size(), Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::mac(), Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::msg(), Botan::CT::poison(), Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::tag_size(), Botan::CT::unpoison(), Botan::Buffered_Computation::update(), Botan::Cipher_Mode::update(), and Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::use_encrypt_then_mac().

352  {
353  update(buffer, offset);
354  buffer.resize(offset);
355 
356  const size_t record_len = msg().size();
357  uint8_t* record_contents = msg().data();
358 
359  // This early exit does not leak info because all the values compared are public
360  if(record_len < tag_size() ||
361  (record_len - (use_encrypt_then_mac() ? tag_size() : 0)) % block_size() != 0)
362  {
363  throw TLS_Exception(Alert::BAD_RECORD_MAC, "Message authentication failure");
364  }
365 
367  {
368  const size_t enc_size = record_len - tag_size();
369 
370  mac().update(assoc_data_with_len(iv_size() + enc_size));
371  if(iv_size() > 0)
372  {
373  mac().update(cbc_state());
374  }
375  mac().update(record_contents, enc_size);
376 
377  std::vector<uint8_t> mac_buf(tag_size());
378  mac().final(mac_buf.data());
379 
380  const size_t mac_offset = enc_size;
381 
382  const bool mac_ok = constant_time_compare(&record_contents[mac_offset], mac_buf.data(), tag_size());
383 
384  if(!mac_ok)
385  {
386  throw TLS_Exception(Alert::BAD_RECORD_MAC, "Message authentication failure");
387  }
388 
389  cbc_decrypt_record(record_contents, enc_size);
390 
391  // 0 if padding was invalid, otherwise 1 + padding_bytes
392  uint16_t pad_size = check_tls_cbc_padding(record_contents, enc_size);
393 
394  // No oracle here, whoever sent us this had the key since MAC check passed
395  if(pad_size == 0)
396  {
397  throw TLS_Exception(Alert::BAD_RECORD_MAC, "Message authentication failure");
398  }
399 
400  const uint8_t* plaintext_block = &record_contents[0];
401  const size_t plaintext_length = enc_size - pad_size;
402 
403  buffer.insert(buffer.end(), plaintext_block, plaintext_block + plaintext_length);
404  }
405  else
406  {
407  cbc_decrypt_record(record_contents, record_len);
408 
409  CT::poison(record_contents, record_len);
410 
411  // 0 if padding was invalid, otherwise 1 + padding_bytes
412  uint16_t pad_size = check_tls_cbc_padding(record_contents, record_len);
413 
414  /*
415  This mask is zero if there is not enough room in the packet to get a valid MAC.
416 
417  We have to accept empty packets, since otherwise we are not compatible
418  with how OpenSSL's countermeasure for fixing BEAST in TLS 1.0 CBC works
419  (sending empty records, instead of 1/(n-1) splitting)
420  */
421 
422  const uint16_t size_ok_mask = CT::is_lte<uint16_t>(static_cast<uint16_t>(tag_size() + pad_size), static_cast<uint16_t>(record_len + 1));
423  pad_size &= size_ok_mask;
424 
425  CT::unpoison(record_contents, record_len);
426 
427  /*
428  This is unpoisoned sooner than it should. The pad_size leaks to plaintext_length and
429  then to the timing channel in the MAC computation described in the Lucky 13 paper.
430  */
431  CT::unpoison(pad_size);
432 
433  const uint8_t* plaintext_block = &record_contents[0];
434  const uint16_t plaintext_length = static_cast<uint16_t>(record_len - tag_size() - pad_size);
435 
436  mac().update(assoc_data_with_len(plaintext_length));
437  mac().update(plaintext_block, plaintext_length);
438 
439  std::vector<uint8_t> mac_buf(tag_size());
440  mac().final(mac_buf.data());
441 
442  const size_t mac_offset = record_len - (tag_size() + pad_size);
443 
444  const bool mac_ok = constant_time_compare(&record_contents[mac_offset], mac_buf.data(), tag_size());
445 
446  const uint16_t ok_mask = size_ok_mask & CT::expand_mask<uint16_t>(mac_ok) & CT::expand_mask<uint16_t>(pad_size);
447 
448  CT::unpoison(ok_mask);
449 
450  if(ok_mask)
451  {
452  buffer.insert(buffer.end(), plaintext_block, plaintext_block + plaintext_length);
453  }
454  else
455  {
456  perform_additional_compressions(record_len, pad_size);
457  throw TLS_Exception(Alert::BAD_RECORD_MAC, "Message authentication failure");
458  }
459  }
460  }
void update(secure_vector< uint8_t > &buffer, size_t offset=0)
Definition: cipher_mode.h:87
bool constant_time_compare(const uint8_t x[], const uint8_t y[], size_t len)
Definition: mem_ops.cpp:44
void poison(const T *p, size_t n)
Definition: ct_utils.h:46
MessageAuthenticationCode & mac() const
Definition: tls_cbc.h:65
secure_vector< uint8_t > & cbc_state()
Definition: tls_cbc.h:71
void final(uint8_t out[])
Definition: buf_comp.h:89
size_t tag_size() const override final
Definition: tls_cbc.h:39
std::vector< uint8_t > assoc_data_with_len(uint16_t len)
Definition: tls_cbc.cpp:121
void update(const uint8_t in[], size_t length)
Definition: buf_comp.h:34
uint16_t check_tls_cbc_padding(const uint8_t record[], size_t record_len)
Definition: tls_cbc.cpp:223
void unpoison(const T *p, size_t n)
Definition: ct_utils.h:57
secure_vector< uint8_t > & msg()
Definition: tls_cbc.h:73

◆ iv_size()

size_t Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::iv_size ( ) const
inlineprotectedinherited

◆ key_spec()

Key_Length_Specification Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::key_spec ( ) const
finaloverridevirtualinherited
Returns
object describing limits on key size

Implements Botan::Cipher_Mode.

Definition at line 84 of file tls_cbc.cpp.

References Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::cbc(), Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::mac(), Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::name(), Botan::SymmetricAlgorithm::set_key(), Botan::Cipher_Mode::set_key(), and Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::valid_nonce_length().

85  {
86  return Key_Length_Specification(m_cipher_keylen + m_mac_keylen);
87  }

◆ mac()

MessageAuthenticationCode& Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::mac ( ) const
inlineprotectedinherited

Definition at line 65 of file tls_cbc.h.

References BOTAN_ASSERT_NONNULL.

Referenced by Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::clear(), Botan::TLS::TLS_CBC_HMAC_AEAD_Encryption::finish(), finish(), Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::key_spec(), and output_length().

66  {
67  BOTAN_ASSERT_NONNULL(m_mac);
68  return *m_mac;
69  }
#define BOTAN_ASSERT_NONNULL(ptr)
Definition: assert.h:81

◆ mac_keylen()

size_t Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::mac_keylen ( ) const
inlineprotectedinherited

Definition at line 57 of file tls_cbc.h.

57 { return m_mac_keylen; }

◆ minimum_final_size()

size_t Botan::TLS::TLS_CBC_HMAC_AEAD_Decryption::minimum_final_size ( ) const
inlineoverridevirtual
Returns
required minimium size to finalize() - may be any length larger than this.

Implements Botan::Cipher_Mode.

Definition at line 158 of file tls_cbc.h.

References BOTAN_TEST_API, and Botan::TLS::check_tls_cbc_padding().

158 { return tag_size(); }
size_t tag_size() const override final
Definition: tls_cbc.h:39

◆ msg()

secure_vector<uint8_t>& Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::msg ( )
inlineprotectedinherited

Definition at line 73 of file tls_cbc.h.

Referenced by Botan::TLS::TLS_CBC_HMAC_AEAD_Encryption::finish(), and finish().

73 { return m_msg; }

◆ name()

std::string Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::name ( ) const
finaloverridevirtualinherited

Implements Botan::Cipher_Mode.

Definition at line 67 of file tls_cbc.cpp.

Referenced by Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::key_spec(), and output_length().

68  {
69  return "TLS_CBC(" + m_cipher_name + "," + m_mac_name + ")";
70  }
std::string m_cipher_name

◆ output_length()

size_t Botan::TLS::TLS_CBC_HMAC_AEAD_Decryption::output_length ( size_t  input_length) const
overridevirtual

Returns the size of the output if this transform is used to process a message with input_length bytes. Will throw if unable to give a precise answer.

Implements Botan::Cipher_Mode.

Definition at line 264 of file tls_cbc.cpp.

References Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::block_size(), Botan::CT::is_equal(), Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::mac(), Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::name(), Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::tag_size(), Botan::unlock(), and Botan::Buffered_Computation::update().

265  {
266  /*
267  * We don't know this because the padding is arbitrary
268  */
269  return 0;
270  }

◆ process()

size_t Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::process ( uint8_t  msg[],
size_t  msg_len 
)
finaloverridevirtualinherited

Process message blocks

Input must be a multiple of update_granularity

Processes msg in place and returns bytes written. Normally this will be either msg_len (indicating the entire message was processed) or for certain AEAD modes zero (indicating that the mode requires the entire message be processed in one pass).

Parameters
msgthe message to be processed
msg_lenlength of the message in bytes

Implements Botan::Cipher_Mode.

Definition at line 115 of file tls_cbc.cpp.

116  {
117  m_msg.insert(m_msg.end(), buf, buf + sz);
118  return 0;
119  }

◆ provider()

virtual std::string Botan::Cipher_Mode::provider ( ) const
inlinevirtualinherited
Returns
provider information about this implementation. Default is "base", might also return "sse2", "avx2", "openssl", or some other arbitrary string.

Reimplemented in Botan::GCM_Mode.

Definition at line 208 of file cipher_mode.h.

208 { return "base"; }

◆ providers()

std::vector< std::string > Botan::Cipher_Mode::providers ( const std::string &  algo_spec)
staticinherited
Returns
list of available providers for this algorithm, empty if not available
Parameters
algo_specalgorithm name

Definition at line 158 of file cipher_mode.cpp.

References Botan::ENCRYPTION, and Botan::get_cipher_mode().

159  {
160  const std::vector<std::string>& possible = { "base", "openssl" };
161  std::vector<std::string> providers;
162  for(auto&& prov : possible)
163  {
164  std::unique_ptr<Cipher_Mode> mode(get_cipher_mode(algo_spec, ENCRYPTION, prov));
165  if(mode)
166  {
167  providers.push_back(prov); // available
168  }
169  }
170  return providers;
171  }
Cipher_Mode * get_cipher_mode(const std::string &algo, Cipher_Dir direction, const std::string &provider)
Definition: cipher_mode.cpp:40
static std::vector< std::string > providers(const std::string &algo_spec)

◆ reset()

void Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::reset ( )
finaloverridevirtualinherited

Resets just the message specific state and allows encrypting again under the existing key

Implements Botan::Cipher_Mode.

Definition at line 60 of file tls_cbc.cpp.

References Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::cbc_state().

Referenced by Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::clear().

61  {
62  cbc_state().clear();
63  m_ad.clear();
64  m_msg.clear();
65  }
secure_vector< uint8_t > & cbc_state()
Definition: tls_cbc.h:71

◆ set_ad()

template<typename Alloc >
void Botan::AEAD_Mode::set_ad ( const std::vector< uint8_t, Alloc > &  ad)
inlineinherited

Set associated data that is not included in the ciphertext but that should be authenticated. Must be called after set_key and before start.

See set_associated_data().

Parameters
adthe associated data

Definition at line 66 of file aead.h.

Referenced by Botan::TLS::write_record().

67  {
68  set_associated_data(ad.data(), ad.size());
69  }
virtual void set_associated_data(const uint8_t ad[], size_t ad_len)=0

◆ set_associated_data()

void Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::set_associated_data ( const uint8_t  ad[],
size_t  ad_len 
)
overridevirtualinherited

Set associated data that is not included in the ciphertext but that should be authenticated. Must be called after set_key and before start.

Unless reset by another call, the associated data is kept between messages. Thus, if the AD does not change, calling once (after set_key) is the optimum.

Parameters
adthe associated data
ad_lenlength of add in bytes

Implements Botan::AEAD_Mode.

Reimplemented in Botan::TLS::TLS_CBC_HMAC_AEAD_Encryption.

Definition at line 130 of file tls_cbc.cpp.

Referenced by Botan::TLS::TLS_CBC_HMAC_AEAD_Encryption::set_associated_data().

131  {
132  if(ad_len != 13)
133  throw Exception("Invalid TLS AEAD associated data length");
134  m_ad.assign(ad, ad + ad_len);
135  }

◆ set_associated_data_vec()

template<typename Alloc >
void Botan::AEAD_Mode::set_associated_data_vec ( const std::vector< uint8_t, Alloc > &  ad)
inlineinherited

Set associated data that is not included in the ciphertext but that should be authenticated. Must be called after set_key and before start.

See set_associated_data().

Parameters
adthe associated data

Definition at line 51 of file aead.h.

Referenced by Botan::TLS::write_record().

52  {
53  set_associated_data(ad.data(), ad.size());
54  }
virtual void set_associated_data(const uint8_t ad[], size_t ad_len)=0

◆ set_key() [1/3]

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

Set the symmetric key of this transform

Parameters
keycontains the key material

Definition at line 178 of file cipher_mode.h.

Referenced by botan_cipher_set_key(), and Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::key_spec().

179  {
180  set_key(key.data(), key.size());
181  }
void set_key(const std::vector< uint8_t, Alloc > &key)
Definition: cipher_mode.h:178

◆ set_key() [2/3]

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

Set the symmetric key of this transform

Parameters
keycontains the key material

Definition at line 187 of file cipher_mode.h.

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

188  {
189  set_key(key.begin(), key.length());
190  }
void set_key(const std::vector< uint8_t, Alloc > &key)
Definition: cipher_mode.h:178

◆ set_key() [3/3]

void Botan::Cipher_Mode::set_key ( const uint8_t  key[],
size_t  length 
)
inlineinherited

Set the symmetric key of this transform

Parameters
keycontains the key material
lengthin bytes of key param

Definition at line 197 of file cipher_mode.h.

198  {
199  if(!valid_keylength(length))
200  throw Invalid_Key_Length(name(), length);
201  key_schedule(key, length);
202  }
virtual std::string name() const =0
bool valid_keylength(size_t length) const
Definition: cipher_mode.h:168

◆ start() [1/3]

template<typename Alloc >
void Botan::Cipher_Mode::start ( const std::vector< uint8_t, Alloc > &  nonce)
inlineinherited

Begin processing a message.

Parameters
noncethe per message nonce

Definition at line 44 of file cipher_mode.h.

Referenced by botan_cipher_start(), Botan::TLS::check_tls_cbc_padding(), Botan::TLS::TLS_CBC_HMAC_AEAD_Encryption::set_associated_data(), and Botan::TLS::write_record().

45  {
46  start_msg(nonce.data(), nonce.size());
47  }
virtual void start_msg(const uint8_t nonce[], size_t nonce_len)=0

◆ start() [2/3]

void Botan::Cipher_Mode::start ( const uint8_t  nonce[],
size_t  nonce_len 
)
inlineinherited

Begin processing a message.

Parameters
noncethe per message nonce
nonce_lenlength of nonce

Definition at line 54 of file cipher_mode.h.

55  {
56  start_msg(nonce, nonce_len);
57  }
virtual void start_msg(const uint8_t nonce[], size_t nonce_len)=0

◆ start() [3/3]

void Botan::Cipher_Mode::start ( )
inlineinherited

Begin processing a message.

Definition at line 62 of file cipher_mode.h.

63  {
64  return start_msg(nullptr, 0);
65  }
virtual void start_msg(const uint8_t nonce[], size_t nonce_len)=0

◆ tag_size()

size_t Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::tag_size ( ) const
inlinefinaloverridevirtualinherited
Returns
the size of the authentication tag used (in bytes)

Reimplemented from Botan::Cipher_Mode.

Definition at line 39 of file tls_cbc.h.

Referenced by Botan::TLS::TLS_CBC_HMAC_AEAD_Encryption::finish(), finish(), Botan::TLS::TLS_CBC_HMAC_AEAD_Encryption::output_length(), and output_length().

39 { return m_tag_size; }

◆ update()

void Botan::Cipher_Mode::update ( secure_vector< uint8_t > &  buffer,
size_t  offset = 0 
)
inlineinherited

Process some data. Input must be in size update_granularity() uint8_t blocks.

Parameters
bufferin/out parameter which will possibly be resized
offsetan offset into blocks to begin processing

Definition at line 87 of file cipher_mode.h.

References BOTAN_ASSERT.

Referenced by botan_cipher_update(), Botan::XTS_Encryption::finish(), Botan::ChaCha20Poly1305_Encryption::finish(), Botan::CFB_Encryption::finish(), Botan::CBC_Encryption::finish(), Botan::EAX_Encryption::finish(), Botan::XTS_Decryption::finish(), Botan::CFB_Decryption::finish(), Botan::CTS_Encryption::finish(), Botan::CBC_Decryption::finish(), Botan::TLS::TLS_CBC_HMAC_AEAD_Encryption::finish(), Botan::CTS_Decryption::finish(), and finish().

88  {
89  BOTAN_ASSERT(buffer.size() >= offset, "Offset ok");
90  uint8_t* buf = buffer.data() + offset;
91  const size_t buf_size = buffer.size() - offset;
92 
93  const size_t written = process(buf, buf_size);
94  buffer.resize(offset + written);
95  }
#define BOTAN_ASSERT(expr, assertion_made)
Definition: assert.h:29
virtual size_t process(uint8_t msg[], size_t msg_len)=0

◆ update_granularity()

size_t Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::update_granularity ( ) const
finaloverridevirtualinherited
Returns
size of required blocks to update

Implements Botan::Cipher_Mode.

Definition at line 72 of file tls_cbc.cpp.

73  {
74  return 1; // just buffers anyway
75  }

◆ use_encrypt_then_mac()

bool Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::use_encrypt_then_mac ( ) const
inlineprotectedinherited

◆ valid_keylength()

bool Botan::Cipher_Mode::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 168 of file cipher_mode.h.

169  {
170  return key_spec().valid_keylength(length);
171  }
virtual Key_Length_Specification key_spec() const =0
bool valid_keylength(size_t length) const
Definition: key_spec.h:51

◆ valid_nonce_length()

bool Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::valid_nonce_length ( size_t  nonce_len) const
finaloverridevirtualinherited
Returns
true iff nonce_len is a valid length for the nonce

Implements Botan::Cipher_Mode.

Definition at line 77 of file tls_cbc.cpp.

References Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::block_size(), and Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::iv_size().

Referenced by Botan::TLS::TLS_CBC_HMAC_AEAD_Mode::key_spec().

78  {
79  if(m_cbc_state.empty())
80  return nl == block_size();
81  return nl == iv_size();
82  }

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