Botan  2.6.0
Crypto and TLS for C++11
Public Member Functions | Static Public Member Functions | Protected Member Functions | Protected Attributes | List of all members
Botan::CFB_Encryption Class Referencefinal

#include <cfb.h>

Inheritance diagram for Botan::CFB_Encryption:
Botan::CFB_Mode Botan::Cipher_Mode

Public Member Functions

virtual bool authenticated () const
 
 CFB_Encryption (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 minimum_final_size () const override final
 
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
 
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 ()
 
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 ()
 

Protected Attributes

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

Detailed Description

CFB Encryption

Definition at line 65 of file cfb.h.

Constructor & Destructor Documentation

◆ CFB_Encryption()

Botan::CFB_Encryption::CFB_Encryption ( 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 74 of file cfb.h.

74  :
75  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 179 of file cipher_mode.h.

179 { 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

Zeroise all state See also reset_msg()

Implements Botan::Cipher_Mode.

Definition at line 23 of file cfb.cpp.

References Botan::CFB_Mode::reset().

24  {
25  m_cipher->clear();
26  reset();
27  }
void reset() override final
Definition: cfb.cpp:29

◆ 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 50 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_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().

53  {
54 #if defined(BOTAN_HAS_OPENSSL)
55  if(provider.empty() || provider == "openssl")
56  {
57  std::unique_ptr<Cipher_Mode> openssl_cipher(make_openssl_cipher_mode(algo, direction));
58 
59  if(openssl_cipher)
60  return openssl_cipher;
61 
62  if(!provider.empty())
63  return std::unique_ptr<Cipher_Mode>();
64  }
65 #endif
66 
67 #if defined(BOTAN_HAS_STREAM_CIPHER)
68  if(auto sc = StreamCipher::create(algo))
69  {
70  return std::unique_ptr<Cipher_Mode>(new Stream_Cipher_Mode(sc.release()));
71  }
72 #endif
73 
74 #if defined(BOTAN_HAS_AEAD_MODES)
75  if(auto aead = AEAD_Mode::create(algo, direction))
76  {
77  return std::unique_ptr<Cipher_Mode>(aead.release());
78  }
79 #endif
80 
81  if(algo.find('/') != std::string::npos)
82  {
83  const std::vector<std::string> algo_parts = split_on(algo, '/');
84  const std::string cipher_name = algo_parts[0];
85  const std::vector<std::string> mode_info = parse_algorithm_name(algo_parts[1]);
86 
87  if(mode_info.empty())
88  return std::unique_ptr<Cipher_Mode>();
89 
90  std::ostringstream alg_args;
91 
92  alg_args << '(' << cipher_name;
93  for(size_t i = 1; i < mode_info.size(); ++i)
94  alg_args << ',' << mode_info[i];
95  for(size_t i = 2; i < algo_parts.size(); ++i)
96  alg_args << ',' << algo_parts[i];
97  alg_args << ')';
98 
99  const std::string mode_name = mode_info[0] + alg_args.str();
100  return Cipher_Mode::create(mode_name, direction, provider);
101  }
102 
103 #if defined(BOTAN_HAS_BLOCK_CIPHER)
104 
105  SCAN_Name spec(algo);
106 
107  if(spec.arg_count() == 0)
108  {
109  return std::unique_ptr<Cipher_Mode>();
110  }
111 
112  std::unique_ptr<BlockCipher> bc(BlockCipher::create(spec.arg(0), provider));
113 
114  if(!bc)
115  {
116  return std::unique_ptr<Cipher_Mode>();
117  }
118 
119 #if defined(BOTAN_HAS_MODE_CBC)
120  if(spec.algo_name() == "CBC")
121  {
122  const std::string padding = spec.arg(1, "PKCS7");
123 
124  if(padding == "CTS")
125  {
126  if(direction == ENCRYPTION)
127  return std::unique_ptr<Cipher_Mode>(new CTS_Encryption(bc.release()));
128  else
129  return std::unique_ptr<Cipher_Mode>(new CTS_Decryption(bc.release()));
130  }
131  else
132  {
133  std::unique_ptr<BlockCipherModePaddingMethod> pad(get_bc_pad(padding));
134 
135  if(pad)
136  {
137  if(direction == ENCRYPTION)
138  return std::unique_ptr<Cipher_Mode>(new CBC_Encryption(bc.release(), pad.release()));
139  else
140  return std::unique_ptr<Cipher_Mode>(new CBC_Decryption(bc.release(), pad.release()));
141  }
142  }
143  }
144 #endif
145 
146 #if defined(BOTAN_HAS_MODE_XTS)
147  if(spec.algo_name() == "XTS")
148  {
149  if(direction == ENCRYPTION)
150  return std::unique_ptr<Cipher_Mode>(new XTS_Encryption(bc.release()));
151  else
152  return std::unique_ptr<Cipher_Mode>(new XTS_Decryption(bc.release()));
153  }
154 #endif
155 
156 #if defined(BOTAN_HAS_MODE_CFB)
157  if(spec.algo_name() == "CFB")
158  {
159  const size_t feedback_bits = spec.arg_as_integer(1, 8*bc->block_size());
160  if(direction == ENCRYPTION)
161  return std::unique_ptr<Cipher_Mode>(new CFB_Encryption(bc.release(), feedback_bits));
162  else
163  return std::unique_ptr<Cipher_Mode>(new CFB_Decryption(bc.release(), feedback_bits));
164  }
165 #endif
166 
167 #endif
168 
169  return std::unique_ptr<Cipher_Mode>();
170  }
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:50
static std::unique_ptr< StreamCipher > create(const std::string &algo_spec, const std::string &provider="")
virtual std::string provider() const
Definition: cipher_mode.h:236
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 40 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().

43  {
44  if(auto mode = Cipher_Mode::create(algo, direction, provider))
45  return mode;
46 
47  throw Lookup_Error("Cipher mode", algo, provider);
48  }
static std::unique_ptr< Cipher_Mode > create(const std::string &algo, Cipher_Dir direction, const std::string &provider="")
Definition: cipher_mode.cpp:50
virtual std::string provider() const
Definition: cipher_mode.h:236

◆ 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 63 of file cfb.cpp.

References Botan::CFB_Mode::block_size().

64  {
65  return block_size();
66  }
size_t block_size() const
Definition: cfb.h:47

◆ feedback()

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

◆ finish()

void Botan::CFB_Encryption::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 157 of file cfb.cpp.

References Botan::Cipher_Mode::update().

158  {
159  update(buffer, offset);
160  }
void update(secure_vector< uint8_t > &buffer, size_t offset=0)
Definition: cipher_mode.h:115

◆ key_spec()

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

Implements Botan::Cipher_Mode.

Definition at line 58 of file cfb.cpp.

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

59  {
60  return cipher().key_spec();
61  }
const BlockCipher & cipher() const
Definition: cfb.h:46
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 53 of file cfb.cpp.

54  {
55  return 0;
56  }

◆ name()

std::string Botan::CFB_Mode::name ( ) const
finaloverridevirtualinherited

Implements Botan::Cipher_Mode.

Definition at line 35 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().

36  {
37  if(feedback() == cipher().block_size())
38  return cipher().name() + "/CFB";
39  else
40  return cipher().name() + "/CFB(" + std::to_string(feedback()*8) + ")";
41  }
size_t feedback() const
Definition: cfb.h:45
std::string to_string(const BER_Object &obj)
Definition: asn1_obj.cpp:145
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. Will throw if unable to give a precise answer.

Implements Botan::Cipher_Mode.

Definition at line 43 of file cfb.cpp.

44  {
45  return input_length;
46  }

◆ process()

size_t Botan::CFB_Encryption::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 114 of file cfb.cpp.

References Botan::copy_mem(), Botan::CFB_Mode::feedback(), Botan::CFB_Mode::m_keystream, Botan::CFB_Mode::m_keystream_pos, Botan::CFB_Mode::shift_register(), and Botan::xor_buf().

115  {
116  const size_t shift = feedback();
117 
118  size_t left = sz;
119 
120  if(m_keystream_pos != 0)
121  {
122  const size_t take = std::min<size_t>(left, shift - m_keystream_pos);
123 
124  xor_buf(m_keystream.data() + m_keystream_pos, buf, take);
125  copy_mem(buf, m_keystream.data() + m_keystream_pos, take);
126 
127  m_keystream_pos += take;
128  left -= take;
129  buf += take;
130 
131  if(m_keystream_pos == shift)
132  {
133  shift_register();
134  }
135  }
136 
137  while(left >= shift)
138  {
139  xor_buf(m_keystream.data(), buf, shift);
140  copy_mem(buf, m_keystream.data(), shift);
141 
142  left -= shift;
143  buf += shift;
144  shift_register();
145  }
146 
147  if(left > 0)
148  {
149  xor_buf(m_keystream.data(), buf, left);
150  copy_mem(buf, m_keystream.data(), left);
151  m_keystream_pos += left;
152  }
153 
154  return sz;
155  }
secure_vector< uint8_t > m_keystream
Definition: cfb.h:50
size_t feedback() const
Definition: cfb.h:45
void shift_register()
Definition: cfb.cpp:100
void xor_buf(uint8_t out[], const uint8_t in[], size_t length)
Definition: mem_ops.h:174
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

◆ 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 236 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().

236 { 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 173 of file cipher_mode.cpp.

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

174  {
175  const std::vector<std::string>& possible = { "base", "openssl" };
176  std::vector<std::string> providers;
177  for(auto&& prov : possible)
178  {
179  std::unique_ptr<Cipher_Mode> mode = Cipher_Mode::create(algo_spec, ENCRYPTION, prov);
180  if(mode)
181  {
182  providers.push_back(prov); // available
183  }
184  }
185  return providers;
186  }
static std::unique_ptr< Cipher_Mode > create(const std::string &algo, Cipher_Dir direction, const std::string &provider="")
Definition: cipher_mode.cpp:50
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 29 of file cfb.cpp.

References Botan::CFB_Mode::m_keystream, and Botan::CFB_Mode::m_state.

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

30  {
31  m_state.clear();
32  m_keystream.clear();
33  }
secure_vector< uint8_t > m_keystream
Definition: cfb.h:50
secure_vector< uint8_t > m_state
Definition: cfb.h:49

◆ 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 206 of file cipher_mode.h.

Referenced by botan_cipher_set_key().

207  {
208  set_key(key.data(), key.size());
209  }
void set_key(const std::vector< uint8_t, Alloc > &key)
Definition: cipher_mode.h:206

◆ 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 215 of file cipher_mode.h.

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

216  {
217  set_key(key.begin(), key.length());
218  }
void set_key(const std::vector< uint8_t, Alloc > &key)
Definition: cipher_mode.h:206

◆ 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 225 of file cipher_mode.h.

226  {
227  if(!valid_keylength(length))
228  throw Invalid_Key_Length(name(), length);
229  key_schedule(key, length);
230  }
virtual std::string name() const =0
bool valid_keylength(size_t length) const
Definition: cipher_mode.h:196

◆ shift_register()

void Botan::CFB_Mode::shift_register ( )
protectedinherited

Definition at line 100 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 process(), and Botan::CFB_Decryption::process().

101  {
102  const size_t shift = feedback();
103  const size_t carryover = block_size() - shift;
104 
105  if(carryover > 0)
106  {
107  copy_mem(m_state.data(), &m_state[shift], carryover);
108  }
109  copy_mem(&m_state[carryover], m_keystream.data(), shift);
111  m_keystream_pos = 0;
112  }
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 72 of file cipher_mode.h.

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

73  {
74  start_msg(nonce.data(), nonce.size());
75  }
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 82 of file cipher_mode.h.

83  {
84  start_msg(nonce, nonce_len);
85  }
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 90 of file cipher_mode.h.

91  {
92  return start_msg(nullptr, 0);
93  }
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::OCB_Mode, Botan::CCM_Mode, Botan::TLS::TLS_CBC_HMAC_AEAD_Mode, Botan::ChaCha20Poly1305_Mode, Botan::GCM_Mode, and Botan::EAX_Mode.

Definition at line 184 of file cipher_mode.h.

Referenced by botan_cipher_get_tag_length().

184 { 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 115 of file cipher_mode.h.

References BOTAN_ASSERT.

Referenced by botan_cipher_update(), Botan::XTS_Encryption::finish(), Botan::ChaCha20Poly1305_Encryption::finish(), 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 Botan::TLS::TLS_CBC_HMAC_AEAD_Decryption::finish().

116  {
117  BOTAN_ASSERT(buffer.size() >= offset, "Offset ok");
118  uint8_t* buf = buffer.data() + offset;
119  const size_t buf_size = buffer.size() - offset;
120 
121  const size_t written = process(buf, buf_size);
122  buffer.resize(offset + written);
123  }
#define BOTAN_ASSERT(expr, assertion_made)
Definition: assert.h:30
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 48 of file cfb.cpp.

References Botan::CFB_Mode::feedback().

49  {
50  return feedback();
51  }
size_t feedback() const
Definition: cfb.h:45

◆ 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 196 of file cipher_mode.h.

197  {
198  return key_spec().valid_keylength(length);
199  }
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::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 68 of file cfb.cpp.

References Botan::CFB_Mode::block_size().

69  {
70  return (n == 0 || n == block_size());
71  }
size_t block_size() const
Definition: cfb.h:47

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 process(), Botan::CFB_Decryption::process(), and Botan::CFB_Mode::shift_register().

◆ m_state

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

Definition at line 49 of file cfb.h.

Referenced by Botan::CFB_Mode::reset(), and Botan::CFB_Mode::shift_register().


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