Botan  2.8.0
Crypto and TLS for C++11
Public Member Functions | Static Public Member Functions | Protected Member Functions | Protected Attributes | List of all members
Botan::CFB_Decryption Class Referencefinal

#include <cfb.h>

Inheritance diagram for Botan::CFB_Decryption:
Botan::CFB_Mode Botan::Cipher_Mode Botan::SymmetricAlgorithm

Public Member Functions

virtual bool authenticated () const
 
 CFB_Decryption (BlockCipher *cipher, size_t feedback_bits)
 
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 maximum_keylength () const
 
size_t minimum_final_size () const override final
 
size_t minimum_keylength () const
 
std::string name () const override final
 
size_t output_length (size_t input_length) const override final
 
size_t process (uint8_t buf[], size_t size) override
 
virtual std::string provider () const
 
void reset () override final
 
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)
 
template<typename Alloc >
void start (const std::vector< uint8_t, Alloc > &nonce)
 
void start (const uint8_t nonce[], size_t nonce_len)
 
void start ()
 
virtual size_t tag_size () const
 
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 n) const override final
 

Static Public Member Functions

static std::unique_ptr< Cipher_Modecreate (const std::string &algo, Cipher_Dir direction, const std::string &provider="")
 
static std::unique_ptr< Cipher_Modecreate_or_throw (const std::string &algo, Cipher_Dir direction, const std::string &provider="")
 
static std::vector< std::string > providers (const std::string &algo_spec)
 

Protected Member Functions

size_t block_size () const
 
const BlockCiphercipher () const
 
size_t feedback () const
 
void shift_register ()
 
void verify_key_set (bool cond) const
 

Protected Attributes

secure_vector< uint8_t > m_keystream
 
size_t m_keystream_pos = 0
 
secure_vector< uint8_t > m_state
 

Detailed Description

CFB Decryption

Definition at line 85 of file cfb.h.

Constructor & Destructor Documentation

◆ CFB_Decryption()

Botan::CFB_Decryption::CFB_Decryption ( BlockCipher cipher,
size_t  feedback_bits 
)
inline

If feedback_bits is zero, cipher->block_size() bytes will be used.

Parameters
cipherblock cipher to use
feedback_bitsnumber of bits fed back into the shift register, must be a multiple of 8

Definition at line 94 of file cfb.h.

94  :
95  CFB_Mode(cipher, feedback_bits) {}
CFB_Mode(BlockCipher *cipher, size_t feedback_bits)
Definition: cfb.cpp:13
const BlockCipher & cipher() const
Definition: cfb.h:46

Member Function Documentation

◆ authenticated()

virtual bool Botan::Cipher_Mode::authenticated ( ) const
inlinevirtualinherited
Returns
true iff this mode provides authentication as well as confidentiality.

Reimplemented in Botan::AEAD_Mode.

Definition at line 169 of file cipher_mode.h.

169 { return false; }

◆ block_size()

size_t Botan::CFB_Mode::block_size ( ) const
inlineprotectedinherited

◆ cipher()

const BlockCipher& Botan::CFB_Mode::cipher ( ) const
inlineprotectedinherited

Definition at line 46 of file cfb.h.

Referenced by Botan::CFB_Mode::key_spec(), Botan::CFB_Mode::name(), and Botan::CFB_Mode::shift_register().

46 { return *m_cipher; }

◆ clear()

void Botan::CFB_Mode::clear ( )
finaloverridevirtualinherited

Reset the state.

Implements Botan::SymmetricAlgorithm.

Definition at line 23 of file cfb.cpp.

References Botan::CFB_Mode::m_keystream, and Botan::CFB_Mode::reset().

24  {
25  m_cipher->clear();
26  m_keystream.clear();
27  reset();
28  }
void reset() override final
Definition: cfb.cpp:30
secure_vector< uint8_t > m_keystream
Definition: cfb.h:50

◆ create()

std::unique_ptr< Cipher_Mode > Botan::Cipher_Mode::create ( const std::string &  algo,
Cipher_Dir  direction,
const std::string &  provider = "" 
)
staticinherited

Create an AEAD mode

Parameters
algothe algorithm to create
directionspecify if this should be an encryption or decryption AEAD
provideroptional specification for provider to use
Returns
an AEAD mode or a null pointer if not available

Definition at line 54 of file cipher_mode.cpp.

References Botan::SCAN_Name::algo_name(), Botan::SCAN_Name::arg(), Botan::SCAN_Name::arg_as_integer(), Botan::SCAN_Name::arg_count(), Botan::BlockCipher::create(), Botan::AEAD_Mode::create(), Botan::StreamCipher::create(), Botan::ENCRYPTION, Botan::get_bc_pad(), Botan::make_commoncrypto_cipher_mode(), Botan::make_openssl_cipher_mode(), Botan::parse_algorithm_name(), Botan::Cipher_Mode::provider(), and Botan::split_on().

Referenced by botan_cipher_init(), Botan::Cipher_Mode::create_or_throw(), Botan::get_cipher_mode(), Botan::pbes2_decrypt(), and Botan::Cipher_Mode::providers().

57  {
58 #if defined(BOTAN_HAS_COMMONCRYPTO)
59  if(provider.empty() || provider == "commoncrypto")
60  {
61  std::unique_ptr<Cipher_Mode> commoncrypto_cipher(make_commoncrypto_cipher_mode(algo, direction));
62 
63  if(commoncrypto_cipher)
64  return commoncrypto_cipher;
65 
66  if(!provider.empty())
67  return std::unique_ptr<Cipher_Mode>();
68  }
69 #endif
70 
71 #if defined(BOTAN_HAS_OPENSSL)
72  if(provider.empty() || provider == "openssl")
73  {
74  std::unique_ptr<Cipher_Mode> openssl_cipher(make_openssl_cipher_mode(algo, direction));
75 
76  if(openssl_cipher)
77  return openssl_cipher;
78 
79  if(!provider.empty())
80  return std::unique_ptr<Cipher_Mode>();
81  }
82 #endif
83 
84 #if defined(BOTAN_HAS_STREAM_CIPHER)
85  if(auto sc = StreamCipher::create(algo))
86  {
87  return std::unique_ptr<Cipher_Mode>(new Stream_Cipher_Mode(sc.release()));
88  }
89 #endif
90 
91 #if defined(BOTAN_HAS_AEAD_MODES)
92  if(auto aead = AEAD_Mode::create(algo, direction))
93  {
94  return std::unique_ptr<Cipher_Mode>(aead.release());
95  }
96 #endif
97 
98  if(algo.find('/') != std::string::npos)
99  {
100  const std::vector<std::string> algo_parts = split_on(algo, '/');
101  const std::string cipher_name = algo_parts[0];
102  const std::vector<std::string> mode_info = parse_algorithm_name(algo_parts[1]);
103 
104  if(mode_info.empty())
105  return std::unique_ptr<Cipher_Mode>();
106 
107  std::ostringstream alg_args;
108 
109  alg_args << '(' << cipher_name;
110  for(size_t i = 1; i < mode_info.size(); ++i)
111  alg_args << ',' << mode_info[i];
112  for(size_t i = 2; i < algo_parts.size(); ++i)
113  alg_args << ',' << algo_parts[i];
114  alg_args << ')';
115 
116  const std::string mode_name = mode_info[0] + alg_args.str();
117  return Cipher_Mode::create(mode_name, direction, provider);
118  }
119 
120 #if defined(BOTAN_HAS_BLOCK_CIPHER)
121 
122  SCAN_Name spec(algo);
123 
124  if(spec.arg_count() == 0)
125  {
126  return std::unique_ptr<Cipher_Mode>();
127  }
128 
129  std::unique_ptr<BlockCipher> bc(BlockCipher::create(spec.arg(0), provider));
130 
131  if(!bc)
132  {
133  return std::unique_ptr<Cipher_Mode>();
134  }
135 
136 #if defined(BOTAN_HAS_MODE_CBC)
137  if(spec.algo_name() == "CBC")
138  {
139  const std::string padding = spec.arg(1, "PKCS7");
140 
141  if(padding == "CTS")
142  {
143  if(direction == ENCRYPTION)
144  return std::unique_ptr<Cipher_Mode>(new CTS_Encryption(bc.release()));
145  else
146  return std::unique_ptr<Cipher_Mode>(new CTS_Decryption(bc.release()));
147  }
148  else
149  {
150  std::unique_ptr<BlockCipherModePaddingMethod> pad(get_bc_pad(padding));
151 
152  if(pad)
153  {
154  if(direction == ENCRYPTION)
155  return std::unique_ptr<Cipher_Mode>(new CBC_Encryption(bc.release(), pad.release()));
156  else
157  return std::unique_ptr<Cipher_Mode>(new CBC_Decryption(bc.release(), pad.release()));
158  }
159  }
160  }
161 #endif
162 
163 #if defined(BOTAN_HAS_MODE_XTS)
164  if(spec.algo_name() == "XTS")
165  {
166  if(direction == ENCRYPTION)
167  return std::unique_ptr<Cipher_Mode>(new XTS_Encryption(bc.release()));
168  else
169  return std::unique_ptr<Cipher_Mode>(new XTS_Decryption(bc.release()));
170  }
171 #endif
172 
173 #if defined(BOTAN_HAS_MODE_CFB)
174  if(spec.algo_name() == "CFB")
175  {
176  const size_t feedback_bits = spec.arg_as_integer(1, 8*bc->block_size());
177  if(direction == ENCRYPTION)
178  return std::unique_ptr<Cipher_Mode>(new CFB_Encryption(bc.release(), feedback_bits));
179  else
180  return std::unique_ptr<Cipher_Mode>(new CFB_Decryption(bc.release(), feedback_bits));
181  }
182 #endif
183 
184 #endif
185 
186  return std::unique_ptr<Cipher_Mode>();
187  }
std::vector< std::string > split_on(const std::string &str, char delim)
Definition: parsing.cpp:144
Cipher_Mode * make_openssl_cipher_mode(const std::string &name, Cipher_Dir direction)
static std::unique_ptr< AEAD_Mode > create(const std::string &algo, Cipher_Dir direction, const std::string &provider="")
Definition: aead.cpp:52
std::vector< std::string > parse_algorithm_name(const std::string &namex)
Definition: parsing.cpp:91
static std::unique_ptr< BlockCipher > create(const std::string &algo_spec, const std::string &provider="")
static std::unique_ptr< Cipher_Mode > create(const std::string &algo, Cipher_Dir direction, const std::string &provider="")
Definition: cipher_mode.cpp:54
static std::unique_ptr< StreamCipher > create(const std::string &algo_spec, const std::string &provider="")
virtual std::string provider() const
Definition: cipher_mode.h:180
Cipher_Mode * make_commoncrypto_cipher_mode(const std::string &name, Cipher_Dir direction)
BlockCipherModePaddingMethod * get_bc_pad(const std::string &algo_spec)
Definition: mode_pad.cpp:18

◆ create_or_throw()

std::unique_ptr< Cipher_Mode > Botan::Cipher_Mode::create_or_throw ( const std::string &  algo,
Cipher_Dir  direction,
const std::string &  provider = "" 
)
staticinherited

Create an AEAD mode, or throw

Parameters
algothe algorithm to create
directionspecify if this should be an encryption or decryption AEAD
provideroptional specification for provider to use
Returns
an AEAD mode, or throw an exception

Definition at line 44 of file cipher_mode.cpp.

References Botan::Cipher_Mode::create(), and Botan::Cipher_Mode::provider().

Referenced by Botan::ECIES_System_Params::create_cipher(), Botan::CryptoBox::decrypt_bin(), Botan::CryptoBox::encrypt(), and Botan::get_cipher().

47  {
48  if(auto mode = Cipher_Mode::create(algo, direction, provider))
49  return mode;
50 
51  throw Lookup_Error("Cipher mode", algo, provider);
52  }
static std::unique_ptr< Cipher_Mode > create(const std::string &algo, Cipher_Dir direction, const std::string &provider="")
Definition: cipher_mode.cpp:54
virtual std::string provider() const
Definition: cipher_mode.h:180

◆ default_nonce_length()

size_t Botan::CFB_Mode::default_nonce_length ( ) const
finaloverridevirtualinherited
Returns
the default size for a nonce

Implements Botan::Cipher_Mode.

Definition at line 64 of file cfb.cpp.

References Botan::CFB_Mode::block_size().

65  {
66  return block_size();
67  }
size_t block_size() const
Definition: cfb.h:47

◆ feedback()

size_t Botan::CFB_Mode::feedback ( ) const
inlineprotectedinherited

◆ finish()

void Botan::CFB_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 224 of file cfb.cpp.

References Botan::Cipher_Mode::update().

225  {
226  update(buffer, offset);
227  }
void update(secure_vector< uint8_t > &buffer, size_t offset=0)
Definition: cipher_mode.h:112

◆ key_spec()

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

Implements Botan::SymmetricAlgorithm.

Definition at line 59 of file cfb.cpp.

References Botan::CFB_Mode::cipher(), and Botan::SymmetricAlgorithm::key_spec().

60  {
61  return cipher().key_spec();
62  }
const BlockCipher & cipher() const
Definition: cfb.h:46
virtual Key_Length_Specification key_spec() const =0

◆ 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_final_size()

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

Implements Botan::Cipher_Mode.

Definition at line 54 of file cfb.cpp.

55  {
56  return 0;
57  }

◆ 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::CFB_Mode::name ( ) const
finaloverridevirtualinherited
Returns
the algorithm name

Implements Botan::SymmetricAlgorithm.

Definition at line 36 of file cfb.cpp.

References Botan::CFB_Mode::block_size(), Botan::CFB_Mode::cipher(), Botan::CFB_Mode::feedback(), Botan::SymmetricAlgorithm::name(), and Botan::ASN1::to_string().

37  {
38  if(feedback() == cipher().block_size())
39  return cipher().name() + "/CFB";
40  else
41  return cipher().name() + "/CFB(" + std::to_string(feedback()*8) + ")";
42  }
size_t feedback() const
Definition: cfb.h:45
std::string to_string(const BER_Object &obj)
Definition: asn1_obj.cpp:210
virtual std::string name() const =0
const BlockCipher & cipher() const
Definition: cfb.h:46
size_t block_size() const
Definition: cfb.h:47

◆ output_length()

size_t Botan::CFB_Mode::output_length ( size_t  input_length) const
finaloverridevirtualinherited

Returns the size of the output if this transform is used to process a message with input_length bytes. In most cases the answer is precise. If it is not possible to precise (namely for CBC decryption) instead a lower bound is returned.

Implements Botan::Cipher_Mode.

Definition at line 44 of file cfb.cpp.

45  {
46  return input_length;
47  }

◆ process()

size_t Botan::CFB_Decryption::process ( uint8_t  msg[],
size_t  msg_len 
)
overridevirtual

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 182 of file cfb.cpp.

References BOTAN_STATE_CHECK, Botan::CFB_Mode::feedback(), Botan::CFB_Mode::m_keystream, Botan::CFB_Mode::m_keystream_pos, Botan::CFB_Mode::m_state, Botan::CFB_Mode::shift_register(), and Botan::SymmetricAlgorithm::verify_key_set().

183  {
184  verify_key_set(m_keystream.size());
185  BOTAN_STATE_CHECK(m_state.empty() == false);
186 
187  const size_t shift = feedback();
188 
189  size_t left = sz;
190 
191  if(m_keystream_pos != 0)
192  {
193  const size_t take = std::min<size_t>(left, shift - m_keystream_pos);
194 
195  xor_copy(buf, m_keystream.data() + m_keystream_pos, take);
196 
197  m_keystream_pos += take;
198  left -= take;
199  buf += take;
200 
201  if(m_keystream_pos == shift)
202  {
203  shift_register();
204  }
205  }
206 
207  while(left >= shift)
208  {
209  xor_copy(buf, m_keystream.data(), shift);
210  left -= shift;
211  buf += shift;
212  shift_register();
213  }
214 
215  if(left > 0)
216  {
217  xor_copy(buf, m_keystream.data(), left);
218  m_keystream_pos += left;
219  }
220 
221  return sz;
222  }
void verify_key_set(bool cond) const
Definition: sym_algo.h:89
secure_vector< uint8_t > m_keystream
Definition: cfb.h:50
size_t feedback() const
Definition: cfb.h:45
#define BOTAN_STATE_CHECK(expr)
Definition: assert.h:49
void shift_register()
Definition: cfb.cpp:103
secure_vector< uint8_t > m_state
Definition: cfb.h:49
size_t m_keystream_pos
Definition: cfb.h:51

◆ 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 180 of file cipher_mode.h.

Referenced by Botan::AEAD_Mode::create(), Botan::Cipher_Mode::create(), Botan::AEAD_Mode::create_or_throw(), and Botan::Cipher_Mode::create_or_throw().

180 { 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 190 of file cipher_mode.cpp.

References Botan::Cipher_Mode::create(), and Botan::ENCRYPTION.

191  {
192  const std::vector<std::string>& possible = { "base", "openssl", "commoncrypto" };
193  std::vector<std::string> providers;
194  for(auto&& prov : possible)
195  {
196  std::unique_ptr<Cipher_Mode> mode = Cipher_Mode::create(algo_spec, ENCRYPTION, prov);
197  if(mode)
198  {
199  providers.push_back(prov); // available
200  }
201  }
202  return providers;
203  }
static std::unique_ptr< Cipher_Mode > create(const std::string &algo, Cipher_Dir direction, const std::string &provider="")
Definition: cipher_mode.cpp:54
static std::vector< std::string > providers(const std::string &algo_spec)

◆ reset()

void Botan::CFB_Mode::reset ( )
finaloverridevirtualinherited

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

Implements Botan::Cipher_Mode.

Definition at line 30 of file cfb.cpp.

References Botan::CFB_Mode::m_keystream, Botan::CFB_Mode::m_state, and Botan::zeroise().

Referenced by Botan::CFB_Mode::clear().

31  {
32  m_state.clear();
34  }
secure_vector< uint8_t > m_keystream
Definition: cfb.h:50
secure_vector< uint8_t > m_state
Definition: cfb.h:49
void zeroise(std::vector< T, Alloc > &vec)
Definition: secmem.h:183

◆ 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

◆ shift_register()

void Botan::CFB_Mode::shift_register ( )
protectedinherited

Definition at line 103 of file cfb.cpp.

References Botan::CFB_Mode::block_size(), Botan::CFB_Mode::cipher(), Botan::copy_mem(), Botan::BlockCipher::encrypt(), Botan::CFB_Mode::feedback(), Botan::CFB_Mode::m_keystream, Botan::CFB_Mode::m_keystream_pos, and Botan::CFB_Mode::m_state.

Referenced by Botan::CFB_Encryption::process(), and process().

104  {
105  const size_t shift = feedback();
106  const size_t carryover = block_size() - shift;
107 
108  if(carryover > 0)
109  {
110  copy_mem(m_state.data(), &m_state[shift], carryover);
111  }
112  copy_mem(&m_state[carryover], m_keystream.data(), shift);
114  m_keystream_pos = 0;
115  }
secure_vector< uint8_t > m_keystream
Definition: cfb.h:50
size_t feedback() const
Definition: cfb.h:45
const BlockCipher & cipher() const
Definition: cfb.h:46
secure_vector< uint8_t > m_state
Definition: cfb.h:49
void copy_mem(T *out, const T *in, size_t n)
Definition: mem_ops.h:108
size_t m_keystream_pos
Definition: cfb.h:51
void encrypt(const uint8_t in[], uint8_t out[]) const
Definition: block_cipher.h:81
size_t block_size() const
Definition: cfb.h:47

◆ 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 69 of file cipher_mode.h.

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

70  {
71  start_msg(nonce.data(), nonce.size());
72  }
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 79 of file cipher_mode.h.

80  {
81  start_msg(nonce, nonce_len);
82  }
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 87 of file cipher_mode.h.

88  {
89  return start_msg(nullptr, 0);
90  }
virtual void start_msg(const uint8_t nonce[], size_t nonce_len)=0

◆ tag_size()

virtual size_t Botan::Cipher_Mode::tag_size ( ) const
inlinevirtualinherited
Returns
the size of the authentication tag used (in bytes)

Reimplemented in Botan::SIV_Mode, Botan::CCM_Mode, Botan::OCB_Mode, Botan::ChaCha20Poly1305_Mode, Botan::TLS::TLS_CBC_HMAC_AEAD_Mode, Botan::GCM_Mode, and Botan::EAX_Mode.

Definition at line 174 of file cipher_mode.h.

Referenced by botan_cipher_get_tag_length().

174 { return 0; }

◆ 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 112 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(), finish(), Botan::CTS_Encryption::finish(), Botan::CBC_Decryption::finish(), Botan::TLS::TLS_CBC_HMAC_AEAD_Encryption::finish(), Botan::CTS_Decryption::finish(), and Botan::TLS::TLS_CBC_HMAC_AEAD_Decryption::finish().

113  {
114  BOTAN_ASSERT(buffer.size() >= offset, "Offset ok");
115  uint8_t* buf = buffer.data() + offset;
116  const size_t buf_size = buffer.size() - offset;
117 
118  const size_t written = process(buf, buf_size);
119  buffer.resize(offset + written);
120  }
#define BOTAN_ASSERT(expr, assertion_made)
Definition: assert.h:55
virtual size_t process(uint8_t msg[], size_t msg_len)=0

◆ update_granularity()

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

Implements Botan::Cipher_Mode.

Definition at line 49 of file cfb.cpp.

References Botan::CFB_Mode::feedback().

50  {
51  return feedback();
52  }
size_t feedback() const
Definition: cfb.h:45

◆ 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

◆ valid_nonce_length()

bool Botan::CFB_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 69 of file cfb.cpp.

References Botan::CFB_Mode::block_size().

70  {
71  return (n == 0 || n == block_size());
72  }
size_t block_size() const
Definition: cfb.h:47

◆ 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::Blowfish::decrypt_n(), Botan::SEED::decrypt_n(), Botan::XTEA::decrypt_n(), Botan::KASUMI::decrypt_n(), Botan::Twofish::decrypt_n(), Botan::CAST_128::decrypt_n(), Botan::MISTY1::decrypt_n(), Botan::SHACAL2::decrypt_n(), Botan::IDEA::decrypt_n(), Botan::Noekeon::decrypt_n(), Botan::DESX::decrypt_n(), Botan::CAST_256::decrypt_n(), Botan::Camellia_128::decrypt_n(), Botan::DES::decrypt_n(), Botan::AES_128::decrypt_n(), Botan::SM4::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::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::SEED::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::Serpent::encrypt_n(), Botan::Threefish_512::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(), Botan::GHASH::ghash_update(), Botan::CFB_Encryption::process(), 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(), Botan::GHASH::update(), Botan::GHASH::update_associated_data(), and Botan::ChaCha::write_keystream().

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

Member Data Documentation

◆ m_keystream

secure_vector<uint8_t> Botan::CFB_Mode::m_keystream
protectedinherited

◆ m_keystream_pos

size_t Botan::CFB_Mode::m_keystream_pos = 0
protectedinherited

Definition at line 51 of file cfb.h.

Referenced by Botan::CFB_Encryption::process(), process(), and Botan::CFB_Mode::shift_register().

◆ m_state

secure_vector<uint8_t> Botan::CFB_Mode::m_state
protectedinherited

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