Botan::CBC_Encryption Class Reference

#include <cbc.h>

Inheritance diagram for Botan::CBC_Encryption:

Public Member Functions
bool	authenticated () const
	CBC_Encryption (std::unique_ptr< BlockCipher > cipher, std::unique_ptr< BlockCipherModePaddingMethod > padding)
void	clear () override final
size_t	default_nonce_length () const override final
void	finish (secure_vector< uint8_t > &final_block, size_t offset=0)
template<concepts::resizable_byte_buffer T>
void	finish (T &final_block, size_t offset=0)
bool	has_keying_material () const override final
size_t	ideal_granularity () const override final
Key_Length_Specification	key_spec () const override final
size_t	maximum_keylength () const
size_t	minimum_final_size () const override
size_t	minimum_keylength () const
std::string	name () const override final
size_t	output_length (size_t input_length) const override
size_t	process (std::span< uint8_t > msg)
size_t	process (uint8_t msg[], size_t msg_len)
virtual std::string	provider () const
virtual bool	requires_entire_message () const
void	reset () override
void	set_key (const SymmetricKey &key)
void	set_key (const uint8_t key[], size_t length)
void	set_key (std::span< const uint8_t > key)
void	start ()
void	start (const uint8_t nonce[], size_t nonce_len)
void	start (std::span< const uint8_t > nonce)
virtual size_t	tag_size () const
template<concepts::resizable_byte_buffer T>
void	update (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

Static Public Member Functions
static std::unique_ptr< Cipher_Mode >	create (std::string_view algo, Cipher_Dir direction, std::string_view provider="")
static std::unique_ptr< Cipher_Mode >	create_or_throw (std::string_view algo, Cipher_Dir direction, std::string_view provider="")
static std::vector< std::string >	providers (std::string_view algo_spec)

Protected Member Functions
void	assert_key_material_set () const
void	assert_key_material_set (bool predicate) const
size_t	block_size () const
const BlockCipher &	cipher () const
const BlockCipherModePaddingMethod &	padding () const
secure_vector< uint8_t > &	state ()
uint8_t *	state_ptr ()

Detailed Description

CBC Encryption

Definition at line 73 of file cbc.h.

Constructor & Destructor Documentation

CBC_Encryption()

Botan::CBC_Encryption::CBC_Encryption ( std::unique_ptr< BlockCipher >  cipher, std::unique_ptr< BlockCipherModePaddingMethod >  padding  )

inline

Parameters

cipher	block cipher to use
padding	padding method to use

Definition at line 80 of file cbc.h.

                                                                          :
         CBC_Mode(std::move(cipher), std::move(padding)) {}

Member Function Documentation

assert_key_material_set() [1/2]

void Botan::SymmetricAlgorithm::assert_key_material_set ( ) const

inlineprotectedinherited

Definition at line 182 of file sym_algo.h.

         {
         assert_key_material_set(has_keying_material());
         }

Referenced by Botan::Salsa20::cipher_bytes(), Botan::AES_128::decrypt_n(), Botan::AES_192::decrypt_n(), Botan::AES_256::decrypt_n(), Botan::ARIA_128::decrypt_n(), Botan::ARIA_192::decrypt_n(), Botan::ARIA_256::decrypt_n(), Botan::Blowfish::decrypt_n(), Botan::Camellia_128::decrypt_n(), Botan::Camellia_192::decrypt_n(), Botan::Camellia_256::decrypt_n(), Botan::CAST_128::decrypt_n(), Botan::DES::decrypt_n(), Botan::TripleDES::decrypt_n(), Botan::GOST_28147_89::decrypt_n(), Botan::IDEA::decrypt_n(), Botan::Lion::decrypt_n(), Botan::Noekeon::decrypt_n(), Botan::SEED::decrypt_n(), Botan::Serpent::decrypt_n(), Botan::SHACAL2::decrypt_n(), Botan::SM4::decrypt_n(), Botan::Threefish_512::decrypt_n(), Botan::Twofish::decrypt_n(), Botan::AES_128::encrypt_n(), Botan::AES_192::encrypt_n(), Botan::AES_256::encrypt_n(), Botan::ARIA_128::encrypt_n(), Botan::ARIA_192::encrypt_n(), Botan::ARIA_256::encrypt_n(), Botan::Blowfish::encrypt_n(), Botan::Camellia_128::encrypt_n(), Botan::Camellia_192::encrypt_n(), Botan::Camellia_256::encrypt_n(), Botan::CAST_128::encrypt_n(), Botan::DES::encrypt_n(), Botan::TripleDES::encrypt_n(), Botan::GOST_28147_89::encrypt_n(), Botan::IDEA::encrypt_n(), Botan::Lion::encrypt_n(), Botan::Noekeon::encrypt_n(), Botan::SEED::encrypt_n(), Botan::Serpent::encrypt_n(), Botan::SHACAL2::encrypt_n(), Botan::SM4::encrypt_n(), Botan::Threefish_512::encrypt_n(), Botan::Twofish::encrypt_n(), Botan::GHASH::final(), Botan::GHASH::ghash_update(), Botan::ChaCha::seek(), Botan::CTR_BE::seek(), Botan::Salsa20::seek(), Botan::OCB_Mode::set_associated_data_n(), Botan::Salsa20::set_iv_bytes(), Botan::GHASH::update(), and Botan::GHASH::update_associated_data().

assert_key_material_set() [2/2]

void Botan::SymmetricAlgorithm::assert_key_material_set ( bool  predicate ) const

inlineprotectedinherited

Definition at line 187 of file sym_algo.h.

         {
         if(!predicate)
            throw_key_not_set_error();
         }

authenticated()

bool Botan::Cipher_Mode::authenticated ( ) const

inlineinherited

Returns

true iff this mode provides authentication as well as confidentiality.

Definition at line 239 of file cipher_mode.h.

{ return this->tag_size() > 0; }

block_size()

size_t Botan::CBC_Mode::block_size ( ) const

inlineprotectedinherited

Definition at line 53 of file cbc.h.

{ return m_block_size; }

Referenced by Botan::CBC_Mode::default_nonce_length(), Botan::CTS_Encryption::minimum_final_size(), Botan::CBC_Decryption::minimum_final_size(), Botan::CTS_Decryption::minimum_final_size(), output_length(), Botan::CBC_Mode::valid_nonce_length(), Botan::CTS_Encryption::valid_nonce_length(), and Botan::CTS_Decryption::valid_nonce_length().

cipher()

const BlockCipher & Botan::CBC_Mode::cipher ( ) const

inlineprotectedinherited

Definition at line 45 of file cbc.h.

{ return *m_cipher; }

Referenced by Botan::CBC_Mode::ideal_granularity(), Botan::CBC_Mode::key_spec(), Botan::CBC_Mode::name(), and Botan::CBC_Mode::update_granularity().

clear()

void Botan::CBC_Mode::clear ( )

finaloverridevirtualinherited

Reset the internal state. This includes not just the key, but any partial message that may have been in process.

Implements Botan::SymmetricAlgorithm.

Definition at line 31 of file cbc.cpp.

   {
   m_cipher->clear();
   reset();
   }

References Botan::CBC_Mode::reset().

create()

std::unique_ptr< Cipher_Mode > Botan::Cipher_Mode::create ( std::string_view  algo, Cipher_Dir  direction, std::string_view  provider = ""  )

staticinherited

Create an AEAD mode

Parameters

algo	the algorithm to create
direction	specify if this should be an encryption or decryption AEAD
provider	optional 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.

   {
#if defined(BOTAN_HAS_COMMONCRYPTO)
   if(provider.empty() || provider == "commoncrypto")
      {
      auto commoncrypto_cipher = make_commoncrypto_cipher_mode(algo, direction);
 
      if(commoncrypto_cipher)
         return commoncrypto_cipher;
 
      if(!provider.empty())
         return std::unique_ptr<Cipher_Mode>();
      }
#endif
 
#if defined(BOTAN_HAS_STREAM_CIPHER)
   if(auto sc = StreamCipher::create(algo))
      {
      return std::make_unique<Stream_Cipher_Mode>(std::move(sc));
      }
#endif
 
#if defined(BOTAN_HAS_AEAD_MODES)
   if(auto aead = AEAD_Mode::create(algo, direction))
      {
      return aead;
      }
#endif
 
   if(algo.find('/') != std::string::npos)
      {
      const std::vector<std::string> algo_parts = split_on(algo, '/');
      std::string_view cipher_name = algo_parts[0];
      const std::vector<std::string> mode_info = parse_algorithm_name(algo_parts[1]);
 
      if(mode_info.empty())
         return std::unique_ptr<Cipher_Mode>();
 
      std::ostringstream mode_name;
 
      mode_name << mode_info[0] << '(' << cipher_name;
      for(size_t i = 1; i < mode_info.size(); ++i)
         mode_name << ',' << mode_info[i];
      for(size_t i = 2; i < algo_parts.size(); ++i)
         mode_name << ',' << algo_parts[i];
      mode_name << ')';
 
      return Cipher_Mode::create(mode_name.str(), direction, provider);
      }
 
#if defined(BOTAN_HAS_BLOCK_CIPHER)
 
   SCAN_Name spec(algo);
 
   if(spec.arg_count() == 0)
      {
      return std::unique_ptr<Cipher_Mode>();
      }
 
   auto bc = BlockCipher::create(spec.arg(0), provider);
 
   if(!bc)
      {
      return std::unique_ptr<Cipher_Mode>();
      }
 
#if defined(BOTAN_HAS_MODE_CBC)
   if(spec.algo_name() == "CBC")
      {
      const std::string padding = spec.arg(1, "PKCS7");
 
      if(padding == "CTS")
         {
         if(direction == Cipher_Dir::Encryption)
            return std::make_unique<CTS_Encryption>(std::move(bc));
         else
            return std::make_unique<CTS_Decryption>(std::move(bc));
         }
      else
         {
         auto pad = BlockCipherModePaddingMethod::create(padding);
 
         if(pad)
            {
            if(direction == Cipher_Dir::Encryption)
               return std::make_unique<CBC_Encryption>(std::move(bc), std::move(pad));
            else
               return std::make_unique<CBC_Decryption>(std::move(bc), std::move(pad));
            }
         }
      }
#endif
 
#if defined(BOTAN_HAS_MODE_XTS)
   if(spec.algo_name() == "XTS")
      {
      if(direction == Cipher_Dir::Encryption)
         return std::make_unique<XTS_Encryption>(std::move(bc));
      else
         return std::make_unique<XTS_Decryption>(std::move(bc));
      }
#endif
 
#if defined(BOTAN_HAS_MODE_CFB)
   if(spec.algo_name() == "CFB")
      {
      const size_t feedback_bits = spec.arg_as_integer(1, 8*bc->block_size());
      if(direction == Cipher_Dir::Encryption)
         return std::make_unique<CFB_Encryption>(std::move(bc), feedback_bits);
      else
         return std::make_unique<CFB_Decryption>(std::move(bc), feedback_bits);
      }
#endif
 
#endif
 
   return std::unique_ptr<Cipher_Mode>();
   }

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

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

create_or_throw()

std::unique_ptr< Cipher_Mode > Botan::Cipher_Mode::create_or_throw ( std::string_view  algo, Cipher_Dir  direction, std::string_view  provider = ""  )

staticinherited

Create an AEAD mode, or throw

Parameters

algo	the algorithm to create
direction	specify if this should be an encryption or decryption AEAD
provider	optional specification for provider to use

Returns

an AEAD mode, or throw an exception

Definition at line 40 of file cipher_mode.cpp.

   {
   if(auto mode = Cipher_Mode::create(algo, direction, provider))
      return mode;
 
   throw Lookup_Error("Cipher mode", algo, provider);
   }

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().

default_nonce_length()

size_t Botan::CBC_Mode::default_nonce_length ( ) const

finaloverridevirtualinherited

Returns

the default size for a nonce

Implements Botan::Cipher_Mode.

Definition at line 65 of file cbc.cpp.

   {
   return block_size();
   }

References Botan::CBC_Mode::block_size().

finish() [1/2]

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

inlineinherited

Complete processing of a message.

Parameters

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

Definition at line 158 of file cipher_mode.h.

         {
         finish_msg(final_block, offset);
         }

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

finish() [2/2]

template<concepts::resizable_byte_buffer T>

void Botan::Cipher_Mode::finish ( T &  final_block, size_t  offset = 0  )

inlineinherited

Complete procession of a message.

Note: Using this overload with anything but a Botan::secure_vector<> is copying the bytes in the in/out buffer.

Parameters

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

Definition at line 174 of file cipher_mode.h.

         {
         Botan::secure_vector<uint8_t> tmp(final_block.begin(), final_block.end());
         finish_msg(tmp, offset);
         final_block.resize(tmp.size());
         std::copy(tmp.begin(), tmp.end(), final_block.begin());
         }

has_keying_material()

bool Botan::CBC_Mode::has_keying_material ( ) const

finaloverridevirtualinherited

Returns

true if a key has been set on this object

Implements Botan::SymmetricAlgorithm.

Definition at line 75 of file cbc.cpp.

   {
   return m_cipher->has_keying_material();
   }

ideal_granularity()

size_t Botan::CBC_Mode::ideal_granularity ( ) const

finaloverridevirtualinherited

Return an ideal granularity. This will be a multiple of the result of update_granularity but may be larger. If so it indicates that better performance may be achieved by providing buffers that are at least that size.

Implements Botan::Cipher_Mode.

Definition at line 55 of file cbc.cpp.

   {
   return cipher().parallel_bytes();
   }

References Botan::CBC_Mode::cipher(), and Botan::BlockCipher::parallel_bytes().

key_spec()

Key_Length_Specification Botan::CBC_Mode::key_spec ( ) const

finaloverridevirtualinherited

Returns

object describing limits on key size

Implements Botan::SymmetricAlgorithm.

Definition at line 60 of file cbc.cpp.

   {
   return cipher().key_spec();
   }

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

maximum_keylength()

size_t Botan::SymmetricAlgorithm::maximum_keylength ( ) const

inlineinherited

Returns

maximum allowed key length

Definition at line 123 of file sym_algo.h.

         {
         return key_spec().maximum_keylength();
         }

minimum_final_size()

size_t Botan::CBC_Encryption::minimum_final_size ( ) const

overridevirtual

Returns

required minimium size to finalize() - may be any length larger than this.

Implements Botan::Cipher_Mode.

Reimplemented in Botan::CTS_Encryption.

Definition at line 103 of file cbc.cpp.

   {
   return 0;
   }

minimum_keylength()

size_t Botan::SymmetricAlgorithm::minimum_keylength ( ) const

inlineinherited

Returns

minimum allowed key length

Definition at line 131 of file sym_algo.h.

         {
         return key_spec().minimum_keylength();
         }

name()

std::string Botan::CBC_Mode::name ( ) const

finaloverridevirtualinherited

Returns

the algorithm name

Implements Botan::SymmetricAlgorithm.

Definition at line 42 of file cbc.cpp.

   {
   if(m_padding)
      return fmt("{}/CBC/{}", cipher().name(), padding().name());
   else
      return fmt("{}/CBC/CTS", cipher().name());
   }

References Botan::CBC_Mode::cipher(), Botan::fmt(), Botan::CBC_Mode::name(), and Botan::CBC_Mode::padding().

Referenced by Botan::CBC_Mode::name().

output_length()

size_t Botan::CBC_Encryption::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. In most cases the answer is precise. If it is not possible to precise (namely for CBC decryption) instead an upper bound is returned.

Implements Botan::Cipher_Mode.

Reimplemented in Botan::CTS_Encryption.

Definition at line 108 of file cbc.cpp.

   {
   if(input_length == 0)
      return block_size();
   else
      return round_up(input_length, block_size());
   }

References Botan::CBC_Mode::block_size(), and Botan::round_up().

padding()

const BlockCipherModePaddingMethod & Botan::CBC_Mode::padding ( ) const

inlineprotectedinherited

Definition at line 47 of file cbc.h.

         {
         BOTAN_ASSERT_NONNULL(m_padding);
         return *m_padding;
         }

References BOTAN_ASSERT_NONNULL.

Referenced by Botan::CBC_Mode::name().

process() [1/2]

size_t Botan::Cipher_Mode::process ( std::span< uint8_t >  msg )

inlineinherited

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

msg	the message to be processed

Returns

bytes written in-place

Definition at line 133 of file cipher_mode.h.

         { return this->process_msg(msg.data(), msg.size()); }

process() [2/2]

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

inlineinherited

Definition at line 135 of file cipher_mode.h.

         { return this->process_msg(msg, msg_len); }

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 250 of file cipher_mode.h.

{ return "base"; }

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

providers()

std::vector< std::string > Botan::Cipher_Mode::providers ( std::string_view  algo_spec )

staticinherited

Returns

list of available providers for this algorithm, empty if not available

Parameters

algo_spec

algorithm name

Definition at line 172 of file cipher_mode.cpp.

   {
   const std::vector<std::string>& possible = { "base", "commoncrypto" };
   std::vector<std::string> providers;
   for(auto&& prov : possible)
      {
      auto mode = Cipher_Mode::create(algo_spec, Cipher_Dir::Encryption, prov);
      if(mode)
         {
         providers.push_back(prov); // available
         }
      }
   return providers;
   }

References Botan::Cipher_Mode::create(), Botan::Encryption, and Botan::Cipher_Mode::providers().

Referenced by Botan::Cipher_Mode::providers().

requires_entire_message()

virtual bool Botan::Cipher_Mode::requires_entire_message ( ) const

inlinevirtualinherited

Certain modes require the entire message be available before any processing can occur. For such modes, input will be consumed but not returned, until finish is called, which returns the entire message.

This function returns true if this mode has this style of operation.

Reimplemented in Botan::CCM_Mode, and Botan::SIV_Mode.

Definition at line 212 of file cipher_mode.h.

{ return false; }

reset()

void Botan::CBC_Mode::reset ( )

overridevirtualinherited

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

Implements Botan::Cipher_Mode.

Reimplemented in Botan::CBC_Decryption.

Definition at line 37 of file cbc.cpp.

   {
   m_state.clear();
   }

Referenced by Botan::CBC_Mode::clear(), and Botan::CBC_Decryption::reset().

set_key() [1/3]

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

inlineinherited

Set the symmetric key of this object.

Parameters

key	the SymmetricKey to be set.

Definition at line 150 of file sym_algo.h.

         {
         set_key(key.begin(), key.length());
         }

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

Referenced by Botan::Sodium::crypto_stream_salsa20(), Botan::Sodium::crypto_stream_salsa20_xor_ic(), Botan::Sodium::crypto_stream_xsalsa20(), Botan::Sodium::crypto_stream_xsalsa20_xor_ic(), Botan::FPE::fe1_decrypt(), Botan::FPE::fe1_encrypt(), and Botan::Sodium::randombytes_buf_deterministic().

set_key() [2/3]

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

inherited

Set the symmetric key of this object.

Parameters

key	the to be set as a byte array.
length	in bytes of key param

Definition at line 17 of file sym_algo.cpp.

   {
   if(!valid_keylength(length))
      throw Invalid_Key_Length(name(), length);
   key_schedule(key, length);
   }

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

set_key() [3/3]

void Botan::SymmetricAlgorithm::set_key ( std::span< const uint8_t >  key )

inlineinherited

Set the symmetric key of this object.

Parameters

key	the contiguous byte range to be set.

Definition at line 159 of file sym_algo.h.

         {
         set_key(key.data(), key.size());
         }

start() [1/3]

void Botan::Cipher_Mode::start ( )

inlineinherited

Begin processing a message.

The exact semantics of this depend on the mode. For many modes, the call will fail since a nonce must be provided.

For certain modes such as CBC this will instead cause the last ciphertext block to be used as the nonce of the new message; doing this isn't a good idea, but some (mostly older) protocols do this.

Definition at line 115 of file cipher_mode.h.

         {
         return start_msg(nullptr, 0);
         }

start() [2/3]

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

inlineinherited

Begin processing a message with a fresh nonce.

Parameters

nonce	the per message nonce
nonce_len	length of nonce

Definition at line 100 of file cipher_mode.h.

         {
         start_msg(nonce, nonce_len);
         }

start() [3/3]

void Botan::Cipher_Mode::start ( std::span< const uint8_t >  nonce )

inlineinherited

Begin processing a message with a fresh nonce.

Parameters

nonce

the per message nonce

Definition at line 90 of file cipher_mode.h.

         {
         start_msg(nonce.data(), nonce.size());
         }

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

state()

secure_vector< uint8_t > & Botan::CBC_Mode::state ( )

inlineprotectedinherited

Definition at line 55 of file cbc.h.

{ return m_state; }

state_ptr()

uint8_t * Botan::CBC_Mode::state_ptr ( )

inlineprotectedinherited

Definition at line 57 of file cbc.h.

{ return m_state.data(); }

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

Definition at line 244 of file cipher_mode.h.

{ return 0; }

update()

template<concepts::resizable_byte_buffer T>

void Botan::Cipher_Mode::update ( T &  buffer, size_t  offset = 0  )

inlineinherited

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

Parameters

buffer	in/out parameter which will possibly be resized
offset	an offset into blocks to begin processing

Definition at line 144 of file cipher_mode.h.

         {
         BOTAN_ASSERT(buffer.size() >= offset, "Offset ok");
         const size_t written = process(std::span(buffer).subspan(offset));
         buffer.resize(offset + written);
         }

References BOTAN_ASSERT.

Referenced by botan_cipher_update().

update_granularity()

size_t Botan::CBC_Mode::update_granularity ( ) const

finaloverridevirtualinherited

Returns

size of required blocks to update

Implements Botan::Cipher_Mode.

Definition at line 50 of file cbc.cpp.

   {
   return cipher().block_size();
   }

References Botan::BlockCipher::block_size(), and Botan::CBC_Mode::cipher().

valid_keylength()

bool Botan::SymmetricAlgorithm::valid_keylength ( size_t  length ) const

inlineinherited

Check whether a given key length is valid for this algorithm.

Parameters

length

the key length to be checked.

Returns

true if the key length is valid.

Definition at line 141 of file sym_algo.h.

         {
         return key_spec().valid_keylength(length);
         }

Referenced by Botan::SymmetricAlgorithm::set_key().

valid_nonce_length()

bool Botan::CBC_Mode::valid_nonce_length ( size_t  nonce_len ) const

overridevirtualinherited

Returns

true iff nonce_len is a valid length for the nonce

Implements Botan::Cipher_Mode.

Reimplemented in Botan::CTS_Encryption, and Botan::CTS_Decryption.

Definition at line 70 of file cbc.cpp.

   {
   return (n == 0 || n == block_size());
   }

References Botan::CBC_Mode::block_size().

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

• src/lib/modes/cbc/cbc.h
• src/lib/modes/cbc/cbc.cpp